\iOHQ^
?s.w
M^^^O^
\0^^
AMERICAN SOCIETY
OF
CIVIL ENGINEERS
January, 1908.
PROCEEDINGS = VOL. XXXIV— No. 1
Pre:
AMERICAN
SOCIETY OF
CIVIL
LENGINEERSj
kFQUNDEOi
:d t
^^ Z^- U. C/VIL
ay
VV,tuAM P. Morse
Published at the House of the Society, aao West Fltty-seventh Street, New York,
the Fourth Wednesday of each Month, except June and July.
CoDvriffhted 1908, by the American Society of Civil Engineers.
Entered as SeS?Class Mat'te/at the New York City Post Office, December 15th, 1896.
Subscription, $6 per annum.
Vol. XXXIV. JANUARY, 1908. No. 1.
AMEEICAN SOCIETY OF CIVIL ENGINEEES.
INSTITUTED 185 3.
PAPERS AND DISCUSSIONS.
This Society is not responsible, as a body, for the facts and opinions advanced
in any of its publications.
CONTENTS.
Papers : page.
Safe Stresses in Steel Columns.
By J. R. Worcester, M. Am. See. C. E 3
Effect of Earthquake Shock on High Buildings.
By R. S. Chew, Assoc. M. Am. Soc. C. E 8
Discussions :
Invar (Nickel-Steel) Tapes on the Measurement of Six Primary Base Lines.
By Messrs. J. A. Ockerson, Horace Andrews, and Noah Cummings 16
Municipal Refuse Disposal: An Investigation.
By Messrs. W. M. Venable, Albert A. Cary, E. H. Foster, B. F. Welton,
C. Herschel Koyl, Louis L. Tribus, and H. Norman Leask 21
The Reinforced Concrete Work of the McGraw Building.
By Messrs. Guy B. Waite, and E. P. Goodrich ; 49
Memoirs :
Nathaniel Henry Hutton, M. Am. Soc. C. E 63
PLATES.
I. Measuring Fort Snelling Base Line with 300-Ft. Steel Tape 17
II. Cinder Concrete Test House 51
HI. The Bon wit-Teller Building and the Salvation Army Warehouse 53
IV. Reinforced Concrete Garage 55
Vol. XXXIV. JANUARY, 1908. No. 1.
AMEEIOAN SOCIETY OF CIVIL ENQINEEES.
INSTITUTED 1852.
PAPERS AND DISCUSSIONS.
This Society is uot responsible, as a body, for the facts and opinions advanced
in any of its publications.
SAFE STRESSES IN STEEL COLUMNS.
By J. E. Worcester, M. Am. Soc. C. E.
To BE Presented February 19th, 1908.
The subject of a proper allowance for stresses in columns has bee^.
treated so often by theorists that it may seem as though no more could
be said on the subject without danger of exhausting the patience of
the engineering profession, but, in spite of all the theories, the prac-
tice of steel designers, as shown by the specifications in general use
to-day, may well bear further consideration.
The reason for this is that all "rational" column formulas, based
on the elastic properties of the steel, are founded on considerations
which are applicable only to ratios of length to radius of gyration far
beyond those allowed in actual construction. It is known, in a gen-
eral way, that steel in compression should not be strained as high as
in tension, and there is a popular impression that the only reason for
this is that when the ratio of I to r increases above 0, or, at most^
above a value very little above 0, the strength becomes lessened rapidly
on this account; but there has been a growing tendency to neglect the
fact that, even in very short columns, there is not the same unit
strength manifested against compressive and tensile stresses.
Note. — ^These papers arc issued before the date set for presentation and discussion.
Correspondence is invited from those who cannot be present at the meeting, and may be
sent by mail to the Secretary. Discussion, either oral or written, will be published
in a subsequent number of Procecdinqs, and, when finally closed, the papers, with
discussion in full, will be published in Transactions.
Pajiors.] Qj^YY. STRESSES IN STEEL COLUMNS 3
The reason for this difference is manifest from a moment's con-
sideration. It may be admitted that, within the elastic limit, the
modulus of elasticity is practically the same, whichever way the metal
is strained — in tension or compression. One may even go further and
admit that the elastic limit is practically the same for both stresses;
but, what happens after the elastic limit is passed? In tension, the
member merely straightens out — if it is not straight to start with —
and stretches, while with every increase in length comes an increase in
resisting strength until the ultimate strength is reached, the final
strength being nearly twice as great as it was at the elastic limit.
In compression, however, soon after the elastic limit is passed, the
column will cripple, and the more it cripples the weaker it becomes.
It is not necessary to consider the ideal conditions of exact equilibrium
in the resisting power of a section, when crippling would not take
place, because the equilibrium — unstable at the best — is not attainable
in practice. On the other hand, it must be admitted that the ductility,
which is of such great advantage in tension, is not present to an
appreciable amount in compression, and that the ratio between work-
ing stresses and destructive stresses in all structures depends on the
compression members, and not the tension, when anything like equal
working units are allowed in the two.
An examination of the results of tests of full-sized columns made
by Tetmajer, Marshall, Christie, Bouscaren, Strobel, Lanza and the
Watertown Arsenal, shows strengths of wrought-iron columns, in which
the I -^ r does not exceed 120, of from 16 000 to 43 000 lb. per sq. in.,
and for mild steel, from 18 000 to 46 000 lb. per sq. in. By far the
larger part of these range between 22 000 and 34 000 lb. for iron, and
between 22 000 and 46 000 lb. for steel. It is very noticeable, also,
that one finds results of more than 28 000 lb. with the longest length
and less than this amount with values of Z -f- r as small as 30. While
the axis drawn through the central portion of the group of these ex-
periments, when plotted, shows some inclination toward lower values
for increased length, the center of the groiip lies at about 30 000 lb.
when I -^ r = 90, and there is very little increase in strength mani-
fested in the tests with a lesser length than this. It is apparent, there-
fore, that if the compression is allowed to run as high as 16 000, the
factor between working stress and ultimate will not exceed 2. In
tension members, on the other hand, the corresponding factor is nearly
4 SAFE STRESSES IN STEEL COLUMNS [Papers.
4. The answer to this argument is, of course, that nobody cares what
the factor between working strain and ultimate may be, as one is
really interested only in the elastic limit, which it is never intended
to reach. Is it not time to call a halt on this line of reasoning? Have
not engineers been overconfident in their ability to design structures
so that all possible contingencies are taken into account? One would
not willingly make use of a material in tension which had no stretch
beyond the elastic limit, yet it would be in no way more hazardous
than to neglect the fact that such is the case with compression mem-
bers, unless a greater factor below the elastic limit were allowed in
these.
The history of the development of the column formulas used in
bridge specifications may shed a little light on the way in which unit
strains have crept up.
The adaptation of the Gordon formula to wrought-iron columns by
Rankine had for a nimierator 36 000 lb. That is, Rankine recom-
mended that this value be assumed for the ultimate strength of
wrought iron in compression of short columns. The earlier specifi-
cations for railroad bridges, in which Rankine's formula was used,
recommended 7 500 or 8 000 in the numerator when 10 000 was used
for tension, and this difference between the numerator of the com-
pression formula and the tensile unit has been retained to a large
extent in specifications until recently,
Wlien the straight-line formula was first introduced, it was recom-
mended for the reason that a straight line could be drawn that would
coincide very well with the plotted results of experiments for ratios
of Z to r between 90 and 150, and that, in giving less values than ex-
periments warranted above this point, it erred on the side of safety.
The straight line, thus drawn, when prolonged the other way, reached
the I —- r = 0 line at about the tensile value of the steel, making the
formula take the form, A ^= B ■ — C X in which A = the allowable
r'
compressive stress, and B ^=^ the allowable tensile stress. This simple
form appealed strongly to engineers, and was readily accepted by
many, but the fact was not recognized by all that the line when plotted
goes far above the experiments for values of Z -f- /• less than 90. The
tables by C. L. Strobel, M. Am. Soe. C. E., for the strength of Z-bar
colunuis were bas(Ml on ;i straight -line fornnila, but this is a notable
instance of recogiiiiioii of tlic error of the formula for short lengths,
Papeis.] SAYT. STRESSES IN* STEEL COLUMNS 5
because he limited his stresses to 12 000 when the straight line went
higher than this amount.
At this point, may be noted what seems to have been an unwar-
ranted change in specitications, due to the reprehensible practice of
copying from one to another with slight changes. There have always
been many engineers who liked the form of the Eankine formula and
refused to give it up. Many appear to have been struck with
the simplicity of the straight-line formula in having the unreduced
compression unit the same as the tension, and, wishing to take ad-
vantage of this feature, but still adhering to the Eankine form, they
adopted the tension unit for the numerator of the formula. This
throws the curve entirely above the field of tests, and, apparently, can-
not be defended by any reasoning.
A later development, of the specifications which are based on the
form of the Rankine formula and still retain the tension unit in the
numerator, is to adopt a lower constant in the denominator. This,
by some, is made 20 000, and by others, 8 000. The former brings the
curve within the outer limits of the group of tests, while the latter
passes well through the middle of the group for values of Z -=- r greater
than 50, but is above the group for lower values.
Perhaps enough has been said to show that the formulas in general
vise to-day need to be sawed off at the end toward low values of I -f- r.
It may also be said that they all need to be amputated at the other end.
Mr. Schneider, years ago, suggested that values of Z -^- r greater than
100 should not be allowed in main members, and this limitation, with
slight variations, has been generally accepted since that time as an es-
sential of good practice.
If, then, the Rankine formula be used, with the numerator value
equal to the tension, and the compression stress be limited to, say,
75% of the tension, and the value of Z -=- r to 100, or thereabouts, one
obtains for a diagram a horizontal line running to a cusp, then a
concave curve running to another cusp, then another straight line.
Could anything be more irrational? The straight-line formula is little
better; the only difference being, that, in the middle portion, there is
a straight line instead of the curve. How much better it would be
to use a continuous curve throughout, embodying its own limitations
at each end!
The late J. B. Johnson, M. Am. Soc. C. E., suggested this same
G SAFE STRESSES IN STEEL COLUMNS [Papers.
thought in his book on Modern Framed Structures, and proijosed a
parabola. This is safe and simple, though, if the vertex is kept down
to a safe value of stress for short lengths, and the limitation of Z -=- r
is made not higher than 120, the central portion of the curve does
not reach as high as tests would warrant.
An elliptical curve fits the case much better, the ellipse being drawn
with its center at the zero value for both stress and I -^- ?% and having
for one semi-diameter the limiting value oi I -^ r, and for the other
tlio limiting stress for zero lengths. The form of this equation is:
B.n- '
(Orf
in which A = the allowable stress, B = the maximum stress at I ^- r
= 0, and C = the maximum value of Z -^- /■ allowed. This curve is
easy enough to plot as an ellipse, but, if a diagram be only arranged
so that on the scale of ordinates B is of the same length as C on the
scale of abscissas, the curve becomes the quadrant of a circle.
The diagram, Fig. 1, illustrates graphically a number of curves of
well-known specifications, together with the results of tests, by the ex-
perimenters previously referred to, reduced so as to allow for a proper
factor of safety. This reduction is made so that the experimental re-
sults can be compared with the formulas in their usual forms. Thi
reduction applied is proportional to the ratio between the tension unit
and the ultimate tensile strength of the metal. That is, for wrought
!•'> 000
iron, the test values are multiplied bv r^ n, ,-,. and for steel the multi-
16 000
i^^^^" ^^ (50 000-
The proposed fornuda, as plotted, is based on limiting values of
compressive stress of 12 000, and oi I -^ r of 120, which appear to be
warranted by experiments and by good practice, and, as the scales are
arranged, the curve is circular.
The writer puts forward a new formula with great diifidence, know-
ing well that custom is a very difficult thing with which to contend,
and how cold a reception new compression formulas have met in the
liast; but, considering how poorly the formulas now in use fulfill the
requirements, and realizing that the public is fully awakened at the
present time to their insufficiency, the time seems to be opportune for
at least suggesting tlio possil)ility of an improvement.
Papers.]
SAFE STRESSES IN STEEL COLUMNS
Vol. XXXIV JANUARY, 1908. No. 1.
AMEEIOAN SOCIETY OF CIVIL ENaiNEEES.
INSTITUTED 1852.
PAPERS AND DISCUSSIONS.
This Society is not responsible, as a body, for tlie facts and opinions advanced
in any of its publications.
EFFECT OF EARTHQUAKE SHOCK ON HIGH
BUILDINGS.
By K. S. Chew, Assoc. M. Am. Soc. C. E.
To BE Presented March 4tii, 1908.
In submitting' this paper, the writer is well aware that he is deal-
ing with a force that can be measured only by the resistance en-
countered; and it was simply with a view of determining the nature
of the stresses induced in structures by a shock, such as that in San
Francisco on April 18th, 1906, that the following was undertaken.
All realize that, with a possible exception, the steel-framed struc-
tures in San Francisco stood this shock. This fact has promoted con-
fidence, and has satisfied architects and owners that such is the safe
type of building for the Pacific Coast. The engineer, however, cannot
be satisfied until he ascertains just how a disturbance of this nature
affects high buildings.
The eft'ect of an earthquake is to produce a complex movement in
the crust of the earth. This movement is a wave motion accompanied
by more or less twisting. This twisting or torsional effect is small,
and affects oidy the first tier of columns. The length of the wave is
very long, so that the vertical movement is small, and, for a stnu'ture
with a well-designed foundation, may be neglected. The effect of the
shock, then, is from the horizontal motion, which is a rapid oscillation.
Note. — These papers are issued before the date set for presentation and discussion.
Correspondence is invited from those who cannot be present at the meeting, and may be
sent by mail to tlic Secretary. Discussion, either oral or written, will be published
in a subsequent number of Proceed i)u)s. and. when finally closed, the papers, with
discussion in full, will be published in Trans(i.etions.
Papers.] EFFECT OF EARTHQUAKE SHOCK ON HIGH BUILDINGS
From iiu'cluiiiit's, it is known that:
Force = Mass acceleration, ov F = M a =
Wa
9
a)
or, the force of the earthquake on any structure is the mass of the
structure into the acceleration produced.
W
, 1 1st Floor
9
Fig. 1.
Imagine the structure represented by Fig. 1 to be built of a per-
fectly rigid material, and that W is the weight of each story; then,
as the foundation takes up the movement of the earth, it endeavors to
set the structure in motion. The inertia of the building resists, and
5 Wa
calls into play the force, F
floor are :
g
S,= 4:
>S3=8
The shearing stresses at each
Wa
9
Wa
9
S,= 2 ~ etc.
9
5 W a ^h
The maximum bending moment = X
9
2'
If these shears and
bending moments could be developed, the building would follow the
movement as a whole. There are, however, no perfectly rigid materials,
so that, under the action of a force, there would be deformation which,
as will be seen later, is different in different types of buildings.
Consider tirst a structure which has no wind bracing. By reference
to Fig. 2 it will be seen that each story weighs W, and that, there-
K)
EFFECT OF EARTHQUAKE SHOCK ON HIGH BUILDINGS [Papers.
fore, the resistance that each story would offer to having set up in an
acceleration, a, woiild be .
<J
The bvTilding, under this action of forces, is a beam cantilever
under a uniform load so that :
Moment of inertia at section 1 — 1 = /^^
li u ii a li 9 o ^ /
assuming I = ' J* then, approximately,
-=T^'^,^z ^';>
II vpill be noticed that J, in Equation 2, does not represent the dis-
placement due to the shock, and may be greater or less than this.
F- 5 Wa
t.
g
\ w
w
X
Wa
g
Wa
g
Wa
g
Wa
g
Wa
g
Fig. 2.
If the building be represented as a single line it can be seen that, as
^ varies directly as a, Iv', and W , and inversely as E and I, that either
of the three curves may be attained, dependent on these variables.
If now, E and 7 be large, and W and L small, and the oscillation
rapid, then the building would endeavor to follow the movement closely,
in which case the curves produced by the oscillation would produce a
wave motion in the structure as shown approximately by Fig. -i.
The writer believes this to be the effect of the late shock as felt on
the majority of low structures. He identifies it as the effect produced
Papers.] EFFECT OF EARTHQUAKE SHOCK ON HIGH BUILDINGS
11
on the three-story apartment house which he was in on that memorable
morning. It was quite different from the effect felt in the fifth story
of a six-story steel-frame structure during a later shock. In the
latter case, there was a decided swinging movement of the building.
Fig. 3.
Referring to Fig. 1, one may note the high shearing stresses pro-
duced. These are, of course, the same in Fig. 2. The bending
moment is a maximum at the foot of the column, and equals :
5 Wa h , _ „^ J
g 2 2
2
(t + ')
(•■5)
Original
Eositii
L
■^^^^^^^^^^^^^^^^^^^^^^^^^^^55^?
1st Bloveuient 1st Reversal
2nd Reversal
3rd Reversal
Fig. 4."
It can be seen at a glance that this type of construction is not
adapted to resist any shocks except those of very small displacement ;
and, even in these, the buildings will fail in § ?
detail. For instance: It was noted, after the fe|3
shock of April 18th, that in a number of cases
the connection of beams to columns had failed
by the rivets shearing off. Reference to Fig.
5 will explain the condition. By referring to
the curves, it will be seen that during the
vibration the column bent, throwing the
V\G.
12 EFFECT OF EARTHQUAKE SHOCK ON HIGH BUILDINGS [Papers.
couple, F F, into action, and the rivets, not being sufficient to stand
this, failed. The writer has also noted several buildings of this type
in which there is a decided crack in the brickwork following the
column, which tends to substantiate this theory.
A wind-braced building will act a little differently from the fore-
going, due to the fact that the point of contraflexure in the columns
is fixed by the bracing, so that the building in part will follow the
movement.
Let D = the horizontal displacement,
t = the time for said horizontal displacement,
a = the acceleration ^ — „^
g = the effect of gravity;
W a WD
then, the force exerted on the building ^ F ^ — , where
9 0 t-
W equals the weight of the building.
If, in Fig. 6, it be assumed that the horizontal girders are stiff
enough to fix the columns at the knees, then the effect on the build-
ing by the movement, D, is as shown.
D' = Aj + A2 -\- h = 2 (^1 + ^2 + ^5) = the de-
formation in building.
Wr, = the weight of the building above and including the first
floor.
W^ = the weight of the building above and including the second
floor.
W^ = the weight of the building above and including the third
floor.
From mechanics, it is known that:
_ Fl^ _ WD^JP_
~ :iE I ~ gf -.IE I ^ ^
W. 1?. T)
•i E I
w, i\
B
'.iEI^
yt^
W, l\
D
^s = ^ ^ r„ etc
* 'd E I^f] t-
Papers.] EFFECT OF EARTHQUAKE SHOCK ON IIIUII BUILDINGS
13
The bending moment is a maximum at the base, and
_ W^D I, W,' I, D
gt'
\ ^ 2, El)
(")
Fig. 6.
These conditions are reached for the movement in one direction.
As this movement is back and forth, it gives the approximate curves
shown by Fig. 7.
It can readily be seen that while the curve, 0 A, shows the curve
in the building for the movement 1 — A, that, before the return move-
ment throws the reverse curve 0 — B into the structure, a portion
14 F.Fl'KCT or EAItTHQUAKE SHOCK ON HIGH BUILDINGS [Papers.
of the frame at the top will endeavor to straighten, or that the point,
0, will move to .r, and that the curve on the beginning of the return
movement will ha x y z A. ' This tendency is aggravated on each re-
verse, and produces the whip action at the top.
Fig. 8.
Fig. 7.
By Equation 5 it may be seen that should D be very small and L
on the first story large, nearly all the bending would occur in the first-
story columns, the building above receiving a
very small force. In this case, the first-story
columns vibrate back and forth, and the build-
ing above is practically stationary. Of course,
this would be productive of a high bending move-
ment in the first-story columns, and a shock of
any magnitude would wreck the building.
If the foregoing analysis is correct, the following may be noted:
1st. — That the stresses produced are similar to those caused by
wind ;
2d. — That, on account of quick reversal, the stresses are increased;
3d. — That, in a wind-braced structure, the total effect is distributed
throughout the structure;
4th. — That, as this effect is a direct function of the weight, the
wall and floor construction should be as light as consistent with
strength ;
5th. — That, as this effect is inversely as the coefficient of elasticity,
the frame should be of a highly elastic material;
Gth. — That, as the effect in buildings that are not wind-braced
varies as the cube of the height, these structures should be limited
in height;
'i'th. — Tliat a inouolitliio fonudation is preferable to one having
isohited footings.
Papers.] kffecT OF EAltTIKJUAKE SHOCK ON IIKill BUJLDINGS 15
These conclusions all point to a steel frame with reinforced walls
and floors as the type of construction for the vicinity of San Francisco.
With respect to reinforced concrete, the writer, although he be-
lieves it to be a valuable combination, thinks it unsuited to resist
the forces that an earthquake shock would produce in a high building,
for the following reasons :
1st. — This type of construction is not adapted to resisting reversed
stresses ;
2d.- — It cannot take shock ;
3d. — The construction is heavy, which conflicts with Conclusion 4;
4th. — The coefficient of elasticity is low, which does not agree with
Conclusion 5;
5th. — The high bending moments produced in columns and girders
would make their designs uneconomical;
6th. — Added to these, when it is considered that any failure in
detail will necessitate the renewal of several entire members, the dis-
advantages of this construction will be seen.
Finally, the writer would recommend:
I.^ — The building to have lattice girders of the Warren type, as
deep as the spandrel section will allow, running entirely around the
structure at every floor. The advantage of this construction is
obvious : Being in the center of the wall, the brickwork or concrete
can be built around the members, the wall thereby being reinforced,
the girder can be designed economically for the different floors. Be-
ing deep, it forms the lintel over the windows and at the same time
decreases the length of the column.
11. — Monolithic foundations.
III. — Reinforced concrete walls, the reinforcement to run hori
zontally and vertically.
IV. — Floor slab to be of rock concrete at least 3J in. thick.
V. — Floors cut up by a large number of openings to be braced so
that they can transmit all horizontal shear to the columns.
VI. — Wind bracing connections to be designed to develop the main
member.
VII. — Wind bracing to be carried to the ground.
VIII. — Columns to be calculated for an extreme fiber stress of
12 000 lb.
Vol XXXIV. JANUARY, 1908. No. 1.
AMEEIOAN SOCIETY OF CIVIL ENGINEEES.
INSTITUTED 18 5 2.
PAPERS AND DISCUSSIONS.
This Society is not responsible, as a body, for the facts and opinions advanced
in any of its publications.
INVAR (NICKEL-STEEL) TAPES ON THE
MEASUEEMENT OF SIX PRIMARY
BASE LINES.
Diyciissiou.*
By Messrs. J. A. Ockerson, Horace Andrews, and Noah Cummings.
Mr. Ockerson. J. A. OcKERSON, M. Am. Soc. C. E. (by letter). — Mr. French's ac-
count of the progress made in the use of steel tapes in geodetic work
is interesting and valuable. The old-time methods of using bars or
rods for the measurement of base lines were both laborious and ex-
pensive, and, as a consequence, the intervals between such lines in a
system of triangulation were entirely too long.
Professor Woodward's paper on long steel tapes, and the discus-
sion thereon,t gave an account of the use of steel tapes in connection
with the triangulation work of the Coast Survey.
The official reports of the Mississippi and Missouri River Commis-
sions, of earlier date by several years, gave accounts of the steel-tape
work on their respective surveys, which included high-grade triangu-
lation, where the length of the triangle sides and the closure required
were such as to compare favorably with so-called primary work.
In August, 1880, the writer made use of a steel tape in the
measurement of a base line 6 063 ft. long, opposite Grafton, 111., in
connection with the triangulation in that vicinity, and, although the
(M|uipment was deticient in many respects, the results obtained were
♦This discussinn (of the paper by Owen B. French, M. Am. Soc. C. E., printed in
Proceedings for October, 1907), is printed in Proceeding'^ in order that the views expressed
may be brought before all members for further discussion.
f Transactions, Am. Soc. C. E., Vol. XXX, pp. 8M0r and 638-652.
PLATE I.
PAPERS, AM. SOC. C. E.
JANUARY, 1908.
OCKERSON ON
STEEL TAPES.
1 *ii*-^1,
Fig. 1.— Measuring Fort Snelling Base Line with 3G0-Ft. Steel Tape,
Rear End of Tape.
Fig. 2.— Front End of Tape, Fort Snelling Base Line, Showing Tension Device.
Papers.] DISCUSSION ON INVAR (nICKEL-STEEL) TAPES 17
STich as to establish practically the use of the steel tape in the ex- Mr. Ockerson.
tensive triangulation work which followed, from the mouth of the
Ohio to the headwaters of the Mississippi.
The writer believes this to be the first use of the steel tape in re-
fined geodetic work, at least in the United States.
The methods of manipulation in the field were modified and im-
proved, in the interest of both economy and accuracy, as experience
developed the defects.
Mr. O. B. Wheeler, of the Missoviri River Commission, is entitled
to the credit of introducing an accurate tension adjuster, which is
described in the Annual Report of that Commission for 1886.
The use of metal strips on which to mark the graduated extremi-
ties of the successive tape lengths was also developed in the river sur-
veys. This was a very important step, as it virtually permitted the
graphical results of each tape length to be transferred from the field
to the ofiice, where the discussion could be taken up at leisure.
Mr. Marshall, in connection with the survey of the Red River,
made a number of improvements, among which was the use of two
tapes of different metals at one and the same time.
The greatest source of error in the use of the steel tape lies in
failure to secure its temperature, as it is much more sensitive to
changes than the thermometer used in connection therewith. The
writer had in mind a method of diminishing the difference between
the two, by the construction of a thermometer with an elongated
bulb of the same material as the tape, and perhaps extending the
metal along the back of the glass scale tube. The invar tape, ap-
parently, eliminates much of the objection to the steel tape incident
to changes of temperature.
In the Mississippi River triangulation, the measurement of base
lines became so easy that the general practice called for a base line at
intervals of about 12 triangles. That is to say, the instrumental
errors of centering both instrument and target, and errors of point-
ing, were larger than the errors of base measurement, hence such
errors were largely localized by the use of frequent bases.
In the writer's opinion, each tape should be standardized by
measuring a primary base the length of which has been determined
by a Repsold or other refined base-measuring apparatus. The measur-
ing should be done under conditions and by methods identical with
those to be used in the measurement of a new base, in preference to
relying on a laboratory determination of the length of the tape.
Table 9 gives some results of base-line measurements with steel
tapes on the Mississippi River Triangulation. The measurements were
generally made in the morning, before sunrise, when changes of
temperature were not very rapid. The lengths are given in round
numbers, omitting the decimals.
18
DISCUSSIOX ox INVAU (KICKEL-STEEL) TAPES [Papers.
Mr. Ockerson TABLE 9. — SoME RESULTS OF BaSE-LiNE MEASUREMENTS WITH StEEL
Tapes on the Mississippi River Triangulation.
Mr. Andrews.
Location.
Length of base line, in feet.
Discrepancy between suc-
cessive measurements.
New Boston
18 066
5 624
7 105
7 00]
5 312
6 486
5 223
6 783
5 379
5 400
5 401
5 700
5 400
4 798
1 in 759 000
Rapid City
594 917
East Dubuque
346 965
Cassville
266 412
Prairie du ( 'hien
" 265 000
DeSoto
929 300
Trempeleau
'• 2 396 000
Wabasha
740 000
Red Wing
" 8 400 000
Fort Snellin^
517 000
Monticello
" 1 475 000
Rice
" 2 969 000
Brainard
Aitkin
438 400
'• 1 304 000
The method of handling the tape is shown by the photographs on
Plate I. Single measurements of lines 1 mile long have been made
in 28 min. In the lines cited, no eifort was made to secure a very
high degree of accuracy, but simply to keep within the limit of dis-
crepancy between two measurements, 1 in 250 000, as prescribed.
Horace Andrews. M. Am. Soc. C. E.(by letter). — The engineer-
ing profession is indebted to Mr. French for his clear and useful
exposition of the practical adaptability of invar to field use.
There would seem to be little left to be desired in base-measuring
apparatus, now that temperature corrections are so well eliminated.
The history of base measurement has' been one of constant struggle
against the uncertainty of temperature corrections. At present, the
use of iced bars, steel tapes, and night work, enables high precision
to be attained, together with speed and economy passing all former
experiences. A further and most important advance, from the
economical standpoint, is now assured through the use of this wonder-
ful alloy.
Previous to the six base lines referred to by Mr. French, some
35 base lines of primary importance had been measured in the United
States. The three earliest, one in 1834 and two in 1844, measured
1
with the Hassler apparatus, had an average probable error of
Between 1847 and 1873, seven bases were measured by the Coast Sur-
vey, with the Bache-Wiirdemann apparatus, an average probable
error of -__-_--— being indicated. Similai
4:57 000
States
United
l>r()bal)l(' error o
..ake Survey,
f five base;
from
1
ajiparatus used l)y the
1870 to 1875, gave the average
Till' lu'psold apparatus then
rapois.] DISCUSSION ON INVAR (nICKEL-STEEL) TxVPES 19
canio into use on the Lake Survey, three bases being measured with Mr. Andrews,
an average probable error of oi^^y wv7c~/)nA' The United States Coast
ajid Geodetic Survey, after 1873, measured eight bases with various
apparatus. Two of these, measured in 1891-92 with the iced bar and
steel tape, showed excellent residts. The average probable error of
these eight bases was ^,^- „„^. Then came the phenomenal achieve-
nient of 1900, when the United States Coast and Geodetic Survey,
having commissioned one field party to measure nine bases in a work-
ing season, the aim being to secure a precision of about rnn ofin'
obtained, not only unprecedented economy of time and money, but
an average probable error of only -i i en aaa- This success was due
to the use of the iced bar and steel tapes, as mentioned by Mr. French;
the advantages of invar are those pointed out by him, and are irre-
spective of the higher precision which was incidentally obtained.
Obviously, invar will be an admirable material for precision level-
ing-rods. Its use for pendulum rods was one of the first suggested.
A pendulum, supported by an iron rod, will change its rate about 1
mill, a week, if subjected to a change of temperature of 30° fahr,,
but, with invar having the coefficient given by the author, the change
of rate would be only 2 sec.
It would be interesting to know the exact proportions of nickel
and steel entering into the composition of the invar tapes. In view
of the fact that the coefficient of expansion given in Table 2, is only
one-half that found in Guillaume's 36% of nickel alloy, it would seem
that some change must have been made in the proportions, and if the
name, "invar," is to be adopted, it would be well to have it apply to a
definite nickel-steel alloy; at present, there are two "invar" alloys,
one of which has only half the invariability of the other.
Engineering measurements in general must be made under all con-
ditions of temperature, and it will be of great advantage to be inde-
pendent of temperature corrections. The writer has found it very
advisable to keep temperature notes for important steel-tape measure-
ments, and correct, under the rule of 0.01 ft. in 100 ft., for each
15° fahr. In the surveys for the Boston Back Bay tract, it has been
stated that brass tapes were used, and with the correction of 0.01 ft.
in 100 ft. for 10° fahr. change of temperature. With invar, the cor-
rection would appear" to be 0.01 ft. in 100 ft. for each 44° fahr., so
that temperature corrections would in general be negligible.
Noah Cummings, Assoc. M. Am. Soc. C. E. — The low coefficient Mr.cummings.
of expansion of invar makes it a most desirable material for a tape,
20 DISCUSSION ON INVAR ( NICKEL-STEEL ) TAPES [Papers.
.Mr.Cummings. and the results given in the paper show that it has proved very satis-
factory for base-line measurements.
It could be used to advantage for measuring base lines for city or
bridge triangulations, or wherever great accuracy is required in base-
line work. However, there seem to be serious objections to the use
of the invar tape for ordinary city surveying, even though its low co-
efficient of expansion would practically eliminate temperature correc-
tions. It is more easily bent and less elastic than steel, and, accord-
ing to the makers, requires a reel 16 in. in diameter. Thus great
care must be taken in handling it, and it would need to be retested
every time someone happened to run into it while a measurement was
being made or in case it was stepped on, either of which may easily
happen in ordinary street surveying.
It is a question whether surveying needs to be done more accurately
than the holding of the points established by the survey. When street
corners are marked by stone monuments placed near the surface of
the sidewalk, there is a possible movement due to frosts and to ex-
cavations for building and street construction purposes. If the invar
tape should be developed so as to be more easily handled and then
come into use for city surveying, a greater degree of accuracy would
be obtained; but, to secure the benefits of this, the points established
would have to be marked on stone or concrete monuments either be-
low or extending below the frost line.
Vol. XXXIV. JANUARY, 1908. No. 1.
AMERICAN SOCIETY OP CIVIL ENGINEERS.
INSTITUTED 1853.
PAPERS AND DISCUSSIONS.
This Society is nr.t responsible, as a body, for the tacts and opinions a,dvanced in
any of its publications.
Ml^NTCIPAL REFUSE DISPOSAL:
AN INVESTIGATION.
Discussion.*
By Messrs. W. M. Venable, Albert A. Gary, E. II. Foster, B. F.
Welton, C. IIerschel Koyl, Louis L. Tribus, and
H. Norman Leask.
W. M. Venable, M. Am. Soc. C. E. (by letter). — In this valuable Mr. Venabie.
paper the author proves that the refuse of the Borough of Richmond,
New York City, contains sufficient calorific material to enable it to be
burned without offense, and without using auxiliary fuel. He also
presents data regarding forty incinerating plants in Great Britain,
with the object of determining the best features of design for use in
a proposed plant. The investigation which led to the conclusion that
it is desirable to burn all the refuse in one incinerator, if that is found
practicable, is not given in the paper, nor is there any investigation of
the merits or demerits of incinerators of American design. The writer
is of the opinion that, in the United States, it is seldom desirable to
reburn all refuse, including the ashes from private houses and other
buildings, and would like the author to present in detail the data upon
which this determination, which preceded the investigation reported
in the paper, was based.
Whether or not the method of destroying all wastes in one set of
furnaces will be found the best for municipalities generally, engineers
are indebted to Mr. Fetherston for his thorough work in ascertaining
the quantities of garbage, ashes and rubbish, and their calorific value,
in what may be taken as a representative district. It is remarkable,
* This discussion (of the paper by J. T. Fetherston, Assoc. M. Am. Soc. C. E., printed in
Proceedings for November, 1907), is piinted in Proceedings in order that the views
expressed may be brought before all members for further discussion.
23 DISCUSSION ON MUNICIPAL liEFUSE DISPOSAL [Papers.
Mr. Venable. also, that the best summary of British practice in refuse disposal is
found in this paper, by an American engineer, for nse in America.
Too much praise can hardly be given for the judgment shown in the
preparation of the various tables, although Table 1 was prepared so
long ago as to make it necessary for the reader to guard himself
against the error of assuming that it contains all the data now avail-
able on the subject with which it deals. The work of Messrs. H. de
B. Parsons, Rudolph Hering, W. F. Morse, and others has been pub-
lished since 1904.
From this paper and other available data, it is safe to assume that,
in almost any municipality, if all the household refuse is collected and
brought to one place, the mixture will contain sufficient calorific
energy to make it practicable to burn it without admixture of other
fuel, and to permit the generation of some steam for power purposes
from the heat in the gases of combustion. It does not follow from
this, however, that such collection and disposal is the most advisable.
It can hardly be granted, as a general proposition in cities, that it is
impossible to collect ashes in such condition that sanitary disposal of
them without reburning is impracticable. If such is granted, as ap-
pears to have been done in the present case, there would still be rea-
sons for considering separate collection and burning in separate parts
of an incinerator, keeping ashes separate from garbage and refuse,
both for sanitary reasons and for convenience and economy in actual
burning.
If the reburning of ashes is to be decided from considerations of
economy only, it should be regarded entirely apart from the disposal
of other wastes, for the introduction of ashes into the garbage makes
their disposal much more costly than otherwise, even if it is neces-
sary to furnish a considerable quantity of coal to assist in destroy-
ing the garbage.
While ashes from household fires contain much combustible ma-
terial, they do not contain enough, as a rule, to make up for the cost
of stoking them through a crematory, not including plant charges;
and, unless a very great reduction in weight is secured by reburning,
there will be no saving in total haul by the burning process. Gen-
erally, the weight of ashes passed through a crematory is not very
greatly reduced, although the weight of rubbish and garbage is very
much decreased by burning. There may be cases, however, where a
furnace can be located at the center of a district, and the haul to the
dump is very much longer than that to the furnace, in which cases the
saving in haul will more than counterbalance the cost of dumping,
stoking, interest and dei)reciation on plant, and reloading for haul to
the dump.*
* This matter is discussed in the writer's book, "Garbage Crematories in America,"
John Wiley & Sons, 1906. In this book will also be found descriptions of every type of
crematory installed in the United States, reference to every United States patent o"f interest
in this field, and a list of the more important and representative plants installed by each
builder of such works in tiie United States.
Papers.] DISCUSSION ON MUNICIPAL REFUSE DISPOSAL 23
In the United States it has been customary to dispose of ashes Mr. Venabie.
separately from garbage, from motives of economy, and furnaces for
the disposal of garbage or refuse, or of both combined, have been de-
signed with the expectation that ashes would be excluded. It is prac-
ticable to burn these materials properly without forced draft, and
several builders of crematories have accomplished this successfully,
at prices of disposal per ton quite as low as those obtaining in England
for the mixed refuse; but crematories operating on natural draft can
be abused more readily than those using forced draft, and, conse-
quently, when handled by the ignorant persons who are so often placed
in charge, the furnaces have received the blame that ought to have
been charged against the persons in authority. Of course, very many
crematories of poor design, and crematories attempting to burn ma-
terials for which they have not been fitted, have been installed, and '
the blame has not always been with the operator. Crematories of the
so-called American design are much cheaper to build than those of the
British type, as they require no boiler plant, or power auxiliaries.
They will consume successfully garbage and rubbish of a character
which cannot be burned in those of the British type, and are very
economical in the use of labor in stoking. Therefore they ought not
to be condemned, or left out of consideration in selecting a method of
disposal, but should be installed where economy shows that they will
be most economical in the long run ; and proper precautions should be
taken that they are operated so as not to produce a nuisance.
On the other hand, it is practically impossible to burn ash-bin
refuse with natural draft. The reason is, not that a strong enough
natural draft cannot be obtained, but that the constant opening of
doors for stoking, on account of the large proportion of ashes to actual
fuel in the mixed refuse, admits to the furnace too much air for
proper combustion. This reduces the draft and also causes the pro-
duction of foul odors in the chimney gases. It requires so much more
head to create a proper draft through a mixture of ashes than through
a mixture of rubbish that it is possible to burn the rubbish without
offense, on natural draft, even with doors frequently open, although it
is not possible if a large proportion of ashes is introduced into the
mixture to be burned. Thus, practically all British incinerator
builders have been compelled to adopt forced draft because they reburn
ashes, and to install boilers in order to develop power to obtain it.
When forced draft is used, the stack should be designed merely to carry
off the gases of combustion, not to produce any portion of the head
across the grates. Thus, when the stoking doors are opened, there is
no tendency to draw the air in the stoking room into the furnace;
but, on the other hand, there may be a tendency for the heated gases
within to come out throiigh the open doors, as observed by Mr. Fether-
ston in several British installations. Forced draft, subject to close
24 DISCUSSION ON MUNICIPAL REFUSE DISPOSAL [Papers.
Mr. Venable. regulation, is preferable in any installation, and is a very great safe-
guard against the admission of too much air into the furnace, above
the fires; but it is not the only way in which this can be safeguarded,
and, in many plants, especially in the smaller towns, the advantages
to be derived from the installation of a boiler are not as great as the
disadvantages.
These remarks may be considered as not properly applying as a
discussion of Mr. Fetherston's valuable paper, one of the premises of
which is that the ashes are to be burned. While fully recognizing
this, as a condition precedent to his inquiry, and having no quarrel
with it, in the case of the Borough of Richmond, the writer has
ventured these remarks as perhaps of some interest to others, for con-
ditions which may differ from those stated in this paper.
Mr. Gary. ALBERT A. Cary, Esq. — This paper, viewed from the standpoint of a
furnace and fuel specialist, is of great interest to the speaker, who,
having had considerable experience in burning various fuels of
low calorific value and also fuels carrying large percentages of
moisture, such as spent tan bark, wet refuse wood-pulp shavings, spent
licorice root, bagasse, etc., can well appreciate the difiiculties en-
countered in burning wet municipal wastes; and burning them so as
to obtain sufficient heat for steam-making, which heat is in excess of
that required to evaporate the moisture contained in the fuel, and to
dissociate the fuel (thereby liberating the volatile gases it contains,
vdiich action is necessary before these fuel constituents can burn).
If any fuel be dried and an analysis be made of its chemical com-
position, then, by the use of a modification of the well-known Dulong
formula, a determination of the calorific vak;e of the sample analyzed
can be made. This may or may not be of use in furnace determina-
tions, depending on the nature of the fuel and the value of the sample
as a fair representative of the entire mass of fuel consumed.
It is no easy matter to obtain a representative sample of the entire
fuel consumed during a test, even when the fuel is fairly uniform in
quality, but when its quality is of a very variable nature, such as in
refuse-burning plants, the difficulties in obtaining a small sample of
fair average value become almost insurmovmtable. Aside from this
difficulty, after making calculations from the chemical analysis of a
dried sample, one does not obtain a true calorific value of the fuel, as
this process of determination assumes that the combustion is wholly
an exothermic process, that is, one producing heat with no heat
absorption occurring for internal or external reactions. Such endo-
thermic actions always take place in the process of combustion, as it
requires heat energy to break up solid masses of fuel and liberate and
split up the hydro-carbons, to say nothing of the energy required to
evaporate the moisture, both on the surface and contained hydro-
scopically.
Papers.] DISCUSSION ON MUNICIPAL REFUSE DISPOSAL 25
For this reason, when careful tests are made, the calculated fuel Mr. Cary.
values are found to be higher than those obtained by using the oxygen
fuel calorimeter; the difference between these two values indicates
the heat energy absorbed by endothermic reactions.
Coming now to the fuel calorimeter, reference will be made only
to the work done in the Mahler bomb. By a proper manipulation of
this apparatus, there is no difficulty in determining the true value of
the sample tested, and the results obtained will require no correc-
tions for chemical endothermic actions; but here, also, there is diffi-
culty in obtaining correct samples, representing a fair average of the
whole fuel mass, and it must be remembered that the quantity of
fuel tested weighs only 1 g. (that is, less than 0.04 lb.).
The great difficulty in obtaining the true calorific values of the
refuse by either of these methods, therefore, can be well appreciated,
and the question naturally is: How can this most important value be
determined ?
The answer is prompted by a somewhat extended experience in
making furnace investigations leading to accurate heat balances.
Heat balances are usually obtained by calculations made from the
analysis of the fuel, the quantity of fuel used, the analysis of the
products of combustion, and a proper consideration of the various
furnace losses.
By a somewhat reversed method of calculation, made from a series
of observations, the chemical composition of the fuel may be obtained,
and from it the unknown quantity to be determined, then, with a very
fair degree of accuracy, its value may be found.
The accuracy of such a determination is, unquestionably, far greater
than may be obtained by any system of sampling when such a mixed
fuel as municipal wastes is used.
This method was used in the work of Mr. C. E. Stromeyer, re-
ferred to on page 957,* but he did not carry his work far enough to
obtain sufficiently satisfactory results.
The furnace gas analysis becomes a most important matter in such
test work, and the mere finding of the percentages of COg, O, CO
and N, by difference, by the use of the ordinary Orsat apparatus, will
not give sufficient information, as experience has taught the speaker
that in such work it is necessary to determine the free hydrogen and
hydro-carbons as well.
Mr. Stromeyer also relates, in his report, the failure of his high-
temperature measuring apparatus, which furnishes most important
information. The speaker is continually using such apparatus, with-
out trouble, in furnace tests where much higher temperatures exist.
The speaker does not wish to be understood as criticizing Mr.
Stromeyer in this work, on the contrary, he regards it as very much
* Proceedings, Am. Soc. C. E., for November, 1907.
2G DISCUSSION ON MUNICIPAL REFUSE DISPOSAL [Papers.
Mr. Gary, in advance of any testing work previously done in refuse crematories.
He merely wishes to indicate that this is the most reliable way of
obtaining this much sought for information, when proper testing is
done.
To obtain data needed to make such fuel determinations, one does
not require any other apparatus than that used in making complete
and exhaustive furnace tests, but careful refinements must not be
neglected, both in applying and using the apparatus and in having
them all carefully calibrated.
The work done by Mr. Fetherston, as shown in this paper, to
obtain such information, by fuel sampling methods, is certainly highly
creditable, and the amount of work involved appeals to the speaker
strongly, as he knows by experience what it means.
Concerning the large percentages of moisture held in fuels, the
speaker has profitably passed very wet fuel between a pair of large
cast-iron rolls, with rough faces, one roll being of a little greater
diameter than the other. These rolls, both running at the same num-
ber of revolutions per minute, were held together by large springs
which allowed them to separate when solid chunks reached them.
In this way a large quantity of the contained moisture was squeezed
out, and higher temperatures were obtained in the furnace, as well
as better combustion, for the furnace is the poorest place in the world
to evaporate water.
Mr. Fetherston's statement of the requirements necessary for burn-
ing wet fuel, on page 972* which, as he states, originated with Pro-
fessor Thurston, may be found in the Journal of the Franklin Insti-
tute for 1874, where it will be found to refer especially to spent tan
and wet saw-dust.
For the combustion of moist fuel, the highest fvirnace temperatures
possible are most essential, and that requirement is one of the weakest
features in general garbage incinerating plants. It is firmly believed
that much profitable development is possible in this direction.
The disposition of the highly heated surrounding surfaces men-
tioned is a matter of much importance with such fuel, and combus-
tion chambers must be proportioned to the amount of gaseous matter
and moisture given off by the fuel.
The speaker can hardly admit the statement indicating that com-
bustion shoidd be retarded and limited by spots of dry fviel forming
on the grate and burning to expose wet fuel, thereby stopping com-
bustion. Such conditions should never exist as they indicate bad
design.
To obtain the most desirable results, the combustion of the fuel
should constantly be accelerated.
Pre-heated air, introduced under some pressure, to offset its dilated
*Proceedings, Am. Soc. C. E., for November, 1907.
Papers.] DISCUSSION ON MUNICIPAL REFUSE DISPOSAL 27
condition, will assist in producing such results, as is noted by Mr. Mr. Gary.
Fetherston.
Steam jets should certainly be avoided as much as possible, as there
is altogether too nuich steam given off from the fuel in the furnace,
and steam has a cooling effect on the fire-bed. To obtain the best
results, the steam used to disintegrate the clinker should be super-
heated.
The speaker cannot agree with Mr. Fetherston when he places the
minimum desirable furnace temperature as low as 1 250° fahr., which
is dangerously near the lowest temperature at which some of the gases
found in the furnace will ignite. Such a temperature will surely be
followed by most imperfect combustion.
A furnace should not fall below 1 800° fahr., as experience proves
that, under lower temperatures, both furnace and boiler efficiencies
drop. Further, 2 000° fahr. is too low for a maximum temperature,
as the speaker's best furnace results have always been obtained with
temperatures of 2 500° fahr., or greater.
If a furnace is properly designed and built, there is no reason why
it should not be durable under a temperature of 2 500° fahr., and with
destructor furnace conditions.
The speaker's experience, of many years in furnace work, has
taught him that proper provision for great expansion and contraction
is frequently neglected, and, also, that high-grade refractory materials
are not used as much as they should be, and that high-grade furnace
masons are not employed, but, where all these requirements are met,
the durability of furnaces is greatly increased.
On page 970,* it is noted that Mr. Fetherston assumes a combined
furnace and boiler efficiency of 50 per cent. By the system of testing
referred to in this discussion, the exact efficiency of the furnace can
be obtained. The information thus obtained will also point out
deiinitely the exact causes of inefficiency, and thereby lead to a rapid,
rational, and scientific development and improvement of the system of
garbage incineration, and the time is certainly favorable for work of
this nature, as shown by Mr. Fetherston's earnest work and careful
investigation of existing conditions.
E. H. Foster, M. Am. Soc. C. E. (by letter). — The valuable data Mr. Foster,
which Mr. Fetherston has presented in this paper will certainly be
appreciated by engineers who have occasion to explore this com-
paratively obscure field, and it is certain that the paper will prove an
important addition to the Society's Transactions.
Attention is called to the quotation on page 972* from Professor
Thurston, giving the requirements for success in burning wet fuel:
To insure that "the rapidity of combustion may be precisely equal to
*Proceedings, Am. Soc. C. E., for November, 1907.
28 DISCUSSION ON MUNICIPAL EEFUSE DISPOSAL [Papers.
Mr. Foster, and never exceed the rapidity of desiccation" offers a condition which
is to be steadfastly striven for, but which, unfortunately, can only be
obtained under the most ideal conditions, and one can only hope to
fulfil it when the combined collection of the city's waste is to be
burned. So long as furnaces are required to burn garbage only, or
garbage and rubbish, special provision must be made for carrying out
the above requirements. When garbage alone is burned, fuel must be
added to support combustion. Professor Thurston's remarks show why
coal should be used, and not oil or natural gas, since it is the heated
mass in the coal, and not the volatile matter, which accomplishes the
drying process. The quality of coal need not be high; in fact, coals
of the poorer quality, containing high percentages of ash, are really
more suitable for this purpose. When garbage or rubbish have to be
dealt with, without ashes, some other means must be adopted for pre-
paring the garbage for burning, and, whatever method is used, it
must be carried out inside the furnace, thus it becomes a part of the
detail of the design.
It must not be considered that the chief desideratum is to obtain
the highest possible temperature in any part of the furnace. Such an
impression would be entirely wrong. The temperature, on the contrary,
must be maintained between certain moderate limits, preferably be-
tween 1 800 and 2 000° fahr., but with a minimum never less than 1 250°
fahr. The disadvantages of too high a temperature may be stated as:
Excessive cost of repairs ;
Melting of the dust and clinker, causing it to fetick to the fire-
brick linings inside, and loss of time and labor in cutting
out, periodically, by hammer and chisel, the slag-like
accumulations ;
Discomfort to the operators in removing the clinker from the
furnace.
The limit of low temperature is reached at the point where the
gases of combustion cease to be dissociated and oxidized. It is neces-
sary, then, to maintain a temperature well above this, thus rendering
them thoroughly innocuous, and without which no process of destruc-
tion may be termed sanitary or without nuisance.
In the study of designs of various furnaces intended for destroying
refuse, attention has been drawn to the conservation of the heat by
various recuperating devices, such as an air heater for extracting the
heat from the flue gases and transferring it to the air which is being
fed to the furnace, and the method of cooling the clinkers by taking
up their heat in the same air going to the furnaces. All these devices,
which resemble the conventional economizers and air heaters used in
connection with steam-power plants for securing higher efficiency and
economy in fuel consumption, serve an entirely different purpose in
Papers.] DISCUSSION ON MUNICIPAL EEFUSE DISPOSAL 29
the case of destructor furnaces. They are rendered necessary in order Mr. Fos^ter.
to insure a high minimum temperature which must at all times be
maintained, the character of the material fed to the grates being of
such a nature that these precautions are necessary.
Whereas the steam generated from the plant represents a valuable
asset, and, in some instances, can be made to do useful work, doubtless
there will be many cases where, in the absence of a suitable method of
utilizing this power, the steam must be blown off and wasted. As it
is the condition in the furnace which is of most importance, even if
the steam generated is wasted, the devices for recovering the heat must
be used.
On page 978* Mr. Fetherston siiggests a further improvement
which might be made in the Westmount plant, namely, to utilize the
heat contained in the hot clinker for raising the temperature of the
air for combustion. This idea is being carried out in the city plant
now under construction.
It is a mistake to rely on the recommendation that the conversion
of the power of the destructor plant into electrical energy is the most
suitable outlet for that power. Mr. Fetherston mentions the pumping
of water or sewage as an appropriate use. A still inore appropriate
use would seem to be the manufacture of ice, for which such a plant
is strikingly well adapted. For instance, with an absorption ice ma-
chine, 9 lb. of ice may be readily procured by the burning of 1 lb. of
coal imder the grates of the boiler, whereas, in a destructor plant of
50 tons capacity, 1 lb. of steam may be readily evaporated per pound
of mixed refuse destroyed. A 50-ton destructor plant would serve a
community with a population of approximately 40 000. By comparing
these figures it will be seen that a 50-ton refuse destructor will pro-
duce 50 tons of ice per day, or an allowance of 2J lb. of ice per
capita, which would be a liberal amount.
An important feature in the design of furnaces is the avoidance
of smoke; this can only be accomplished by isolating completely the
fiirnace and combustion chamber from the water-heating surface con-
nected with the boiler, as the chilling effect produced by contact of the
partially cooled consumed gases against the cold surface of the tube
containing water will suppress complete combustion and result in a
smoky chimney.
B. F. Welton, Assoc. M. Am. See. C. E.— The speaker has fol- ^r. Weiion.
lowed with great interest the development of the work done by Mr.
Fetherston, the results of which are so admirably presented in his
valuable paper.
The speaker's relation to this work, as stated by the author, has
been in connection with the determination of the calorific values in-
corporated in the text of the paper. The purpose of this discussion,
* Proceedings, Am. Soc. C. E., for November, 1907.
30 DISCUSSION ON MUNICIPAL REFUSE DISPOSAL [Papers.
Mr. Welton. therefore, is to describe in some detail the methods used in making
the calorific tests and proximate analyses, in order that the reader may
be enabled to form his own estimate of the relative value of those re-
sults as compared with similar tests of other and more homogeneous
materials used as fuel.
It is also desired to record the results of a series of chemical
analyses of the component parts of the refuse made in the same
laboratories by Professor Stephen F. Peckham, Member of the Ameri-
can Chemical Society, whose assistance has been highly appreciated.
The primary purpose of the experiments was to provide funda-
mental data from which could be determined the feasibility of the
sanitary disposal of the wastes of the Borough of Richmond by self-
combustion, in a refuse destructor of the same general type as used
in Great Britain.
Inasmuch as the matter of heat utilization and power production
was to be taken up ultimately, in connection with the disposal of the
refuse, the resialts of the experiments were also to be considered as
possibly affecting the design of the destructor. If the results of the
calorific tests should show that the material was not suitable for self-
incineration, it was hoped that the chemical analyses might provide
the necessary information for determining some alternative method
of sanitary disposal. On the other hand, if the material should be
found suitable, the chemical analyses might furnish additional data
for the stvidy of means for the prevention of possible nuisance by the
escape of the products of combiistion, or for tlie recovery of com-
mercially valuable material.
After the conclusion of trial calorific tests on two sets of samples
to ascertain what methods of handling the material in the laboratory
would secure the desired uniformity of results, a consultation was held
between the author and the speaker to define the scope of the experi-
ments.
It was decided :
First. — That, if the experiments were to be conclusive, they should
be extended over a period of at least a full year, thus showing the
entire seasonal variation in the character of the collections, which
variation, it was thought, might be sufficient to interfere, perhaps, to
a serious degree, with the successful operation of a destructor;
Second. — That the samples should be taken with sufficient fre-
quency and in such manner as to be truly representative of the col-
lections, both as regards the character of the material and the period
covered.
It was finally settled tliot the samples submitted to the laboratory
should represent the daily collections of the Bureau of Street Cleaning
for a period of about two weeks, or a half month.
Pitpcrs.] DISCL'SSION ()\ MLXiCirAL KEL^USE DISi'OSAL 31
The primary sampling- from the actual collections, as well as the Mr. Weltoc.
initial preparation of the half-monthly samples, was to be made under
the direction of Mr. Fetherston.
The sampling, as described in detail by the author, consisted in the
selection of representative material which was subsequently separated,
by sieves and hand-picking, into six general classes as follows :
1. — Garbage,
2. — Coal and cinders,
3.— Rubbish,
4. — Fine ash,
5. — Clinker,
6. — Incombustible material.
The garbage consisted of vegetable and animal matter, etc., such
as ordinarily collected from dwellings.
The coal and cinders was the better portion of the stove and furnace
wastes of the district.
The rubbish consisted of a variety of materials, such as paper,
excelsior, rags, iibrous material, etc.
The fine ash was the material from the general collections which
would pass through a screen of f-in. mesh, and consisted principally
of the finer residue from domestic fires.
The clinker was that contained in the residue from domestic fires,
and those of schools, churches, etc.
The incombustible material was largely glass, metal, stone, bricks,
etc.
The initial preparation of the samples comprised the reduction of
large quantities of material of the several classes by quartering, the
evaporation of nearly all the moisture, and the rough pulverizing of
all samples to effect a uniformity which would serve to make the
samples submitted to the laboratory truly representative.
The weight of these samples was approximately^:
1 lb. of garbage (dry) ;
2 lb. each of coal and cinders, clinker and fine ash;
5 lb. of rubbish.
The condition of the samples, as they arrived at the laboratory,
after going through this preliminary process, was about as follows :
The garbage, in the majority of cases, was fairly dry, but soft and
greasy ; most of it would pass a sieve of ^-in. mesh, and, while the
odor was decidedly in evidence it was not offensively so. Nearly all
the coal and cinders would pass a sieve of I -in. mesh, and showed a
large proportion of unburned coal.
The fine ash and clinker were in about the same condition as the
coal and cinders, except that the difference in the quantity of carbon
present was plainly evident from the color and general appearance.
32 DISCUSSION ON MUNICIPAL REFUSE DISPOSAL [Papers.
Mr. AVelton. The rubbish presented the appearance of shredded rags, paper, etc.
No incombustible material was tested, for obvious reasons.
Upon arrival at the laboratory, each sample was immediately
placed in a wide-mouthed glass jar with a ground-glass stopper, and
as soon as convenieitt thereafter a careful determination was made of
the contained amount of moisture. This operation was conducted
using about 10 g. of garbage and about 5 g. each of the other samples.
The whole of each sample of garbage and rubbish was then made
to pass a sieve of No. 20 mesh by repeated grinding in a small pul-
verizer of the coffee-mill type. The coal and cinders sample was
pulverized in a laboratory ball mill until it would all pass a No. 40
sieve. The clinker and fine ash were treated in the same manner.
The samples were then replaced in their respective glass jars and
thoroughly mixed by agitation.
Proximate analyses were next made, determining again the
moisture, and, in addition, the volatile matter, fi.xed carbon, and ash.
For these determinations, the following weights of material were used:
Garbage about 1.5 g.
Coal and cinders " 2.0 "
Clinker " 2.0 "
Fine ash " 2.0 "
Kubbish " 0.5 "
These quantities of the several materials were taken at random
directly from the jar containing the whole sample, since it was found
that practical duplication of results could readily be obtained without
further reduction in size or quantity of the sample.
All determinations of moisture were made by using an electric
oven kept at a constant temperature of about 180° fahr. The coarse
samples were allowed to remain in the oven for about 18 hours, but
only about 1^ hours were necessary when the samples were in the
pulverized condition. The volatile matter was determined by placing
the dried material in a small, covered, porcelain crucible, over a three-
flame Bunsen burner, care being taken that all the carbon deposited
during the combustion of the volatile hydro-carbon was afterward con-
sumed by the Bunsen flame. (Platinum crucibles were first used for
this work, but some constituent of the coal and cinders, which was
later discovered to be tin, probably from tin cans, re-acted with the
platinum, ruining the crucibles, and their use was abandoned).
The fixed carbon then remaining in the crucible was next reduced
to ash by open burning over the same Bunsen flame until no loss in
weight occurred.
The percentages of the various determinations were reduced by
calculation to the basis of the condition of samples as they were re-
ceived at the laboratory, and the garbage analyses were still further
Papers.] DISCUSSION ON MUNICIPAL REFUSE DISPOSAL 33
modified to represent the conditions in the original sample before Mr. Weitou.
evaporation of any of its moisture, a record of the evaporative tests
being sent to the laboratory with each sample.
The calorific values were determined by the Mahler bomb calorim-
eter, which provides for the combustion of the material in the presence
of oxygen at a pressure of 25 atmospheres.
The tests were made using the following weights of material :
Garbage 0.80 to 1.00 g.
Coal and cinders 0.50 « 0.Y5 "
Kubbish 0.35 " 0.50 "
Fine ash 0.50 " 0.75 "
Clinker 0.50 " 0.75 "
These values, as obtained by the actual tests, were reduced to values
per pound of dry sample, original sample, and combustible, in that
order, using the corrected proximate analyses as a basis. These are
the figures that appear in Tables 6 and 7.
There was no diflSculty in securing satisfactory combustion, ex-
cept in the tests of "fine ash" and "clinker," in which the percentage
of inert matter was so high that it prevented ignition of the com-
bustible portion of the sample by the ordinary means. In these cases,
therefore, a small amount of naphthaline was introduced with the
sample to start the combustion, and a deduction, representing the
calorific value of the naphthaline used, was made subsequently.
The residue from the combustion of the garbage was hard, vitreous,
and invariably in the form of small globules of a brownish black color.
That of the coal and cinders was naturally about the same in appear-
ance as the ash of anthracite coal, while the rubbish left little more
that could be seen with the eye than a stain on the combustion tray.
At the beginning of the experiments, tests were made in duplicate
on all samples until it became evident that the differences in results,
as shown by the duplications, were well within the variation that
might easily occur in the primary selection of representative samples.
In amount, these differences were generally less than 1% of the
calorific value of the dry material. By this time, also, the uniformity
in the character of each class of material, as shown by the calorific
value per pound of combustible, began to be noticeable, and it was
observed that this value would serve to detect errors in manipulation
and computation as well as to indicate the occasions when duplication
was required. As a consequence, tests on the same sample were rarely
repeated thereafter, unless the value per pound of combustible was at
some variance with the average of the other tests already made.
To those who are not familiar with the calorific values of the
staple fuels, such as anthracite and bituminous coals, it may appear
that no great confidence should be placed in the results of these tests
34 DISCUSSION ON MUNICIPAL KEFUSE DISPOSAL [Papers.
Mr. Weiton. on material which would naturally be expected to vary widely in
character. As a matter of fact, the experiments have shown a uni-
formity of character in the material which is all the more remarkable
in that it was not anticipated. Indeed, now, when all the data are at
hand, the conclusion might easily be drawn that in the instances where
the largest variations in calorific values per pound of combustible
occur, this variation is more likely to be due to the difficulty of ob-
taining representative samples from the collections than from actual
differences in character.
Moreover^ few who have had no occasion to study the matter of
analyses and calorific tests of coal are aware of the variation in fuel
value of its combustible portion or what is known as "pure coal."
In this respect the figures in Table 12 are of interest. These
are deduced from :
First. — The report of the coal-testing plant of the United States
Geological Survey at St. Louis, in 1904;
Second.^ — From records of the Department of Water Supply,
Gas and Electricity, at Mount Prospect Laboratory, New
York City.
The chemical analyses made by Professor Peckham consisted of
organic analyses of composite samples representing the collections of
the entire period, and inorganic analyses of the residue from burning
the same over a Bunsen flame. They will not be described in detail
here, but the results of both series of analyses have been combined in
Table 13.
These results would have been included in Mr. Fetherston's paper,
except for the fact that their completion was delayed by pressure of
more important matters in the laboratory, and they have only very re-
cently become available.
The same reason also accounts for the relatively large percentage
of undetermined constituents in the garbage sample.
Table 13 also shows a comparison between the calorific value of the
samples, as calculated from the chemical analyses, and as determined
by the calorimeter. The correspondence is believed to be sufficiently
close to serve as a general verification of the entire work. The per-
centages in Table 13 are all computed on the weight of dry samples
as a basis. The presence, in considerable amounts, of volatile hydro-
carbons in the garbage and rubbish samples may be noted if the car-
bon, as shown by the chemical analyses, be compared with the fixed
carbon of the proximate analyses reduced to a dry-sample basis.
In the determination of the moisture in the garbage samples for
the proximate analyses, it is extremely probable that some of the
lighter and more easily volatile hydro-carbons were driven off and
computed as moisture. This is undoubtedly the reason why there is
Papers.] DISCUSSION ON MUNICIPAL REFUSE DISPOSAL
35
1
o
O
A'1 P
O 1 B
! p?
3 o c
3 ^ SJ^
(I » So"
O t-n
'-t
1s=
V c
>d a
o S
o &"
1
c *
C CD
1
I
&g
§-s
0 o
o 9
^^^^ :
■^> —
:^
>
o
j_^
Range, in
cnn>
2
CO
o
British thermal
a
3
3d
o
units.
o-.p
its
KisrO!^
>■
o
o
o
o
b
Percentage
of average
=\
=^
value.
*:=!!< Qa
!>»
8S
t-i
(»
o
Range, in
9^
4^
00
British thermal
g
05
units.
d
10.0
Pijrcentage
of average
•§5!
CO
O
G
=^
^
value.
^»
o
g
w
o
3
o
HH
o'
d
m
CO
Range, in
"— 2 5 S'
p
OQ
00
British thermal
units.
CO
i
^5!
o
o
'o
00
Percentage
of average
=\
.^
value.
Range, in
1
50
British thermal
units.
il'wg
33§°-
r<
"O o 5 «
E»
W
Percentage
o3
g-
Vi
of averae-e
s
=\
^ ,
value.
o
g
ts
Range, in
^ Q
Q
a
to
British thermal
J§w2?S
o
3
3
^
o?
§
units.
oj o •-! cr
F
S5 B-O ?3
W
H
3 a CW3
2 Pots »
M
o»
Percentage
of average
'ESp'-'h*
P
CD
a
^
^
value.
3
O
Ms
1
>
s2
Range, in
WW^
o
Q
OS
British thermal
o
a
g
units.
P^o S
P C (B
a
« ^Ha
.fe
s
Percentage
a - n
i=.o o
S
of average
■ "=3
=^
^
value.
Mr. WelioB
o
M
O
O
>
2
o
<l
t>
r
a
CO
B
W
> ts
M
!> CO
f H
C) CO
H "*
CO >■
■ !^
O
H
M
H
»
O
o
w
H
O
!z!
C!
O
K
W
>
O
H
bd
36
DISCUSSION ON MUNICIPAL REFUSE DISPOSAL
[Papers.
Mr. Weitou. not a closer agreement between the calorific values of dry samples of
garbage, as calculated from the analyses, and as determined in the
calorimeter. The oxygen is determined by difference, and the ash is
the average of the proximate analyses reduced to the dry-sample basis.
TABLE 13. — Chemical Analyses of Dry Composite Samples op
Coal and Cinders, Garbage, and Kubbish, Eepresenting Col-
lections FOR the Year 1905-06.
Constituents.
Percentage by weight of:
Carbon
Hydrogen
Nitrogen
Oxygen
Silica
Iron oxide and alumina
Lime
Magnesia
Phosphoric acid
Carbonic acid
Lead
Tin
Alkalies and undetermined
Coal and
cinders.
Garbage.
Rubbish.
55.77
43.10
42.39
0.75
6.24
5.96
0.64
3.70
3.41
2.37
27.74
33.52
30.01
7.56
6.49
8.98
0.41
2.03
1.31
4.26
2.26
Trace.
0.28
0.57
None.
1.47
0.10
None.
0.59
1.49
Trace.
Trace.
1 Sulphides, 0.20 ]
0.52
Trace.
0.27
4.45
100.00
1.21
100.00
100.00
Calorific Values, in British Thermal Units.
Calculated from above analyses
Average of calorimeter determinations. .
8 3S2
8 510
7 970
8 351
7 250
7 251
The calculations from the cliemical analyses are made as follows :
62 100 (h — ^) + 14 500 C. = British thermal units.
^ 8 '
Mr. Koyi. C. Herschel Koyl, Esq. (by letter). — This paper presents in ad-
mirable form the results of a very careful, systematic, and thorough
study of the possibility of destroying by fire the mixed wastes of the
Borough of Richmond in a manner innocuous, inoffensive, and not too
costly.
The need of such an investigation was pressing, and its value not
merely local, because the number of small communities in America,
in which this problem is of first importance, is considerable and
growing.
The technical question is whether the mixed waste contains enough
combustible to be self-burning, at a temperature sufiiciently high to
destroy and not merely distil the volatile organic matter. Records
show that, in England and on the Continent, a satisfactory disposal
of mixed municipal refuse is made in this way. but it is also known
Papers.] DISCUSSION ON MUNICIPAL REFUSE DISPOSAL 37
that abroad there is less waste of edible matter than in the United Mr. Koyi.
States; and, therefore, before risking $60 000 of municipal money, it
was the part of wisdom to determine the theoretical fuel efficiency of
the waste of Staten Island. From the character of the examination
and its completeness, Mr. Fetherston's results may be accepted with
confidence, and also his conclusion that a destructor of the English
type will burn the mixed waste of the Borough of Richmond effec-
tively. True, the expense will not be small; but if the destruction of
organic matter is complete and inoffensive to the neighborhood, a cost
of from $1.00 to $1.50 per ton should not be prohibitive, in view of
the fact that any other method of disposition would be extremely
difficult in Staten Island.
Regarding the limits of usefulness of these waste destructors: It
has been proven by eight months' operation in Westmount, Montreal,
that an average of 20 tons of mixed waste per day can be destroyed at
a working cost of 31 cents per ton, and a total cost of 80 cents per
ton ; therefore, a population of 13 000 people is not too small to have
the economical service of a destructor.
An upper limit, however, is reached when considering a city from
which there is enough garbage to make profitable a modern reduction
plant to separate the organic matter into grease and fertilizer. For
instance, the City of New York makes satisfactory disposal of ap-
proximately 3 000 000 tons of mixed waste per year (70% ashes, 12%
street sweepings, 12% garbage and 6% light refuse, by weight) at an
average cost of 40 cents per ton. It would be folly to talk of putting
all this material through destructors at a cost of 75 cents per ton.
Note should be made of a fact not mentioned by Mr. Fetherston,
that in the "coal and cinders" which makes 27% of his total collec-
tion, or about 35% of his ash collection, more than half is not only
burnable coal, but salable coal. This arises from the fact that most
of the coal which gets into the ash-pit is imdersized for the grate and
falls through unburned and indeed unmarked by the fire. The writer
has taken from many sample tons of Manhattan ashes an average of
20% of salable coal, from furnace size down, of which about half,
after being washed, was indistinguishable from coal fresh from the
mine. This means nothing in the Borough of Richmond, but it will
be the determining factor in settling the method of final disposal
where anthracite is used in cities which, at the same time, are large
enough to make profitable the mechanical separation of the coal from
the clinker and ashes. The process is not more difficult than the con-
centration of ore, and there is an average profit of about $2 per ton
of recovered coal.
In the United States the advocates of reduction "utilize" garbage
by separating it into water, grease, and fertilizer. The advocates of
incineration "utilize" dry refuse by picking out its 30% of salable
38 DISCUSSION ON MUNICIPAL REFUSE DISPOSAL [Papers.
Mr. Koyi. paper, rubber, etc., before they burn the remaining 70% of rubbish.
And "utilization" is the keynote to successful policy in any large city.
It now costs New York $1250 000 for the final disposition of its
municipal wastes. It would cost $2 250 000 to put all the waste
through destructors. It would cost about $200 000 to do it scientifi-
cally and save what ought not to be burned or buried, as follows:
Profit from utili-
zation of rubbish
Cost. and coal.
Garbage 360 000 tons (contract) $200 000
Street sweepings 360 000 " at 40 cents 144 000
Ash and clinker. ... 1 680 000 " at 40 cents 672 000
Kubbish 180 000 " burned at
profit $40 000
Coal 420 000 " recovered
at profit 840 000
$1 016 000 $880 000
Less 880 000
$136 000
or, the Department of Final Disposition would be almost self-support-
ing.
Mr. Ti-ibus. Louis L. Tribus, M. Am. Soc. C. E. — This paper gives evidence of
a great deal of work, and the speaker can say from personal knowledge
that, in the Borough of Richmond, and along the lines described,
there has been a vast amount of work which does not appear in the
paper, yet its results will certainly secure great advancement in the
art of refuse disposal.
Prior to the inauguration of the Greater City of New York, Staten
Island (then becoming the Borough of Richmond) was occupied by a
number of corporate villages and a great many small hamlets, the latter
controlled by the usual "township" and "county" system of govern-
ment, the incorporated portions by "village" form, with more or less
intelligent management, as politics determined.
During the first four years following consolidation, little was done,
other than to get accustomed to being a part of the great city.
On January 1st, 1902, under the revised charter, considerable home
rule, and a borough president of character and ability, the first ad-
vance toward real progress was made.
Street cleaning and refuse disposal had been cared for, to a very
limited extent, during the preceding four years, with a small force
of men, but supervised by a man trained under Colonel Waring, who
had the welfare of his subject at heart. The speaker was called upon
by the borough president early in 1902 to act in both professional and
Papers.] DISCUSSION ON MUNICIPAL REFUSE DISPOSAL 39
executive capacities, and take charge of the public works and main- Mr. Tribus.
tenance bureaus of the borough. He was given very free rein in
securing betterments in plan and operation, but, on taking charge, in-
sisted that he was to be free from politics in the work itself. Richard
T. Fox, formerly in charge of the work in Richmond, as noted before,
for the Department of Street Cleaning for the whole city, was placed
in charge of 'the newly created "Bureau of Street Cleaning," which
at this time came under the President of the Borough through the
Commissioner of Public Works. Fairly liberal appropriations were
made, so that, after careful plans had been laid, improvement became
the order of the day. The first step noted was the banishment of
garbage cans and refuse receptacles from the sidewalks and streets as
far as possible, all such being removed by collectors from behind the
buildings, the empty cans being then returned to their places. The
next step toward efficiency and the establishment of esprit de forps
among the men, was made by placing them all in uniform; the third
step was to employ the men continuously throughout the year, so as
to render service daily instead of spasmodically. This, of course, ap-
plied more to street cleaning, pure and simple, than to refuse collec-
tion which, formerly also, had to be more or less regular throughout
the year.
After some two years' service, Mr. Fox accepted a call to the City
of Chicago, to show there what scientific and business methods could
accomplish in the way of street cleaning and refuse disposal.
Mr. Fetherston, as a member of the borough engineer corps, had
been assigned to specific work in connection with local scientific tests
in refuse disposal, in which work he gave so good an account of him-
self that when Mr. Fox resigned he was selected to take the place of
"Superintendent."
The paper describes very clearly the course taken, which has led
to the recommendation and the actual construction of the first refuse
destructor of this type in the United States. It is confidently hoped
that in a few years this paper will be supplemented by one describing
the destructor and telling of its efficient operation. That, however,
will depend largely on the intelligence exhibited in its management,
for the best piece of machinery may give poor results unless well
handled.
In studying the refuse disposal question in the Borough of Rich-
mond, it has been necessary to estimate very carefully the probable
development of this specific locality, as its conditions are changing
very rapidly year by year. It is not improbable that, within the life
of the present generation, the whole island will be practically built
up with residences, factories, stores, and valuable water-front improve-
ments. This would mean that it would be impossible to find places
for the burial of garbage, for maintaining ash dumps, and for any
40 DISCUSSION ON MUNICIPAL KEFUSE DISPOSAL [Papers.
Mr. Tribus. of the nuisance-producing plants for the destruction of garbage by
low-temperature cooking. All experiments, therefore, in the past six
years have been directed toward finding a process that would convert
refuse, without nuisance, into some useful or innocuous material. The
investigations which have been made so carefully by Mr. Fetherston
and others assigned to the work from time to time, therefore, have
been directed specially to this system; as, by process of elimination,
all other systems were dismissed as not suitable for the probable local
conditions of development, hence the conclusion that mixed refuse
destruction promised more to the Borough of Richmond than did any
other process; though it should be clearly understood that other sys-
tems might be more advantageous in other communities under differ-
ent conditions, and time may prove that even in Richmond some dif-
ferent method may be evolved. In view of these explanations, the
special studies, almost exclusively, have been directed toward acquiring
information about and perfecting plans for mixed-refuse destructors,
with the primary object of collecting materials at the lowest expense
and converting them into an innocuous product without causing
nuisance in the process, and it seems probable that the high-tempera-
ture system planned will accomplish the object desired. Up to the
present time, theory and experiment indicate that, not only will the
material collected have sufficient fuel value in itself to convert it into
inoffensive slag, but that, in addition, there will be developed a liberal
amount of heat units.
In the installation under construction, there is provided a bqiler
which, it is expected, can be operated by the otherwise wasted heat
units, so as to furnish ultimately all the power and light needed at
the plant. If the results justify the expectations, it is probable, also,
that the slag from the destructor will eventually be ground up, and,
with an admixture of cement, be converted into paving blocks, which
would have value for gutters and pavement in places where traffic is
not specially heavy. That feature, however, is only being considered
for the future, the present epoch being confined to what might be
called the self-destruction of the refuse collected.
If success attends the operation of the new plant, it is expected
that, ultimately, six or seven similar plants will be installed in other
portions of the borough, as near as possible to the centers of collection;
with one concession, however, to public sentiment, placing the de-
structors in manufacturing districts, near a railroad, or at the water
front, rather than in residence localities.
Mr. Fetherston's paper covers the general phase of the refuse de-
structor, from the standpoint of economy in gathering garbage and
other refuse and disposing of it finally. He has not gone particularly
into the reasons why prompt final disposal of refuse is desirable. There
are, perhaps, throe reasons why every community should take care of
Papers.] DISCUSSION ON MUNICIPAL REFUSE DISPOSAL 41
this feature of urban life: First, that which appeals most popularly Mr. Tribus.
to citizens, the removal of refuse materials because they are obnoxious
to the senses of smell and sight; second, because the keeping of de-
caying organic matters near habitations is generally supposed to breed
disease; and, third, a reason which should have more consideration,
though it has not been taken up extensively, that, during the heat of
the summer, when the house fly develops and feeds and thrives on
refuse, it is a very prolific distributor of disease. It is, to begin with,
not a cleanly insect, and feeds on decaying matter; then, as likely
as not, it proceeds to the nearest receptacle containing milk, for a
drink, and not infrequently a bath ; the combination is often too much
for the fly, and it remains for a few moments or several hours float-
ing around in the milk, leaving in it very often the germs of disease,
which in turn thrive very readily in the milk and are taken into the
human system. During the summer, the human system, particularly
in infancy and childhood, is in excellent condition for the growth of
disease germs in the intestines, and the various so-called summer
complaints ensue. While probably no one as yet will claim that all
intestinal diseases are caused by flies; by the process of elimination,
in records that have been kept in certain places by intelligent ob-
servers, the fly can very fairly be charged with a great deal of the
trouble. The mosquito has borne its share of public contumely as a
dispenser of yellow fever; why should not the ordinary house fly be
given credit for the work which undoubtedly it can do, and which
many are beginning to believe it does do ? If this is the case, the
community that promptly removes and disposes of its decaying
organic matters should, first, enjoy the presence of a lessened num-
ber of flies, and, second, a lessened number of cases of intestinal disease.
This subject is only mentioned here as one worthy of fuller investiga-
tion, rather than as a conclusion based upon observation.
This whole topic of refuse collection and disposal is one of very
great interest, and is a field as yet almost untouched in the United
States, and, prior to the publication of this paper, very little, of much
real value and based on facts, has been printed. The speaker hopes
that additional information will be gathered, not only in the Borough
of Richmond, but in other places, and be put at the disposal of this
Society, to aid in this most important work.
H. Norman Leask, Esq. — The speaker, being conversant with the Mr. Leask.
literature on this subject, and having had long experience in design-
ing and operating destructor plants, ventures the opinion that, for
engineers, this is one of the most valuable papers which has ever been
presented. It is the more valuable as it enters a new field and presents
data from which a contracting engineer can design plants and guaran-
tee results without risk of failure to either of the contracting parties.
It is pleasing to note that the author has commenced with first
42 DISCUSSION ON MUNICIPAL REFUSE DISPOSAL [Papers.
Bir. Leask. principles, and not at some place in the middle of the subject, which,
unfortunately, is often done. The exact figures in the paper, however,
do not apply generally, and must be used with the discrimination born
of experience, due allowance being made for losses, after the manner
set forth in the problematic balance sheet. Table 9.
The information in the paper has not been available heretofore in
such extended form; and, as far as the speaker is aware, it has not
covered such a long period, or such a great weight of refuse. At the
same time, it should be remembered that an inspection of material is
desirable, in order to note any peculiarities in its character, without
which immediate success is not likely to result.
When the author took up the question, the conditions existing in
the Borough of Richmond were practically the same as those which
have induced most cities to resort to destruction by fire. In many
cities abroad other methods have been tried, such as reduction, making
fertilizer, and gasification for lighting and power purposes, all of
which have failed signally to deal completely and in a satisfactory
manner with the final disposition of refuse of all classes, which is
the chief desideratum. The only system of final disposal which is
growing in use, and is now quite general, is the destruction or
cleansing of refuse by fire, thus rendering it innocuous.
That an examination of existing garbage crematories in the United
States should offer no hope of meeting the requirements satisfactorily,
is not surprising, for such crematories can hardly be termed engineer-
ing propositions, and one doubts very much whether American engi-
neers have had anything to do with their design. The principal faults
which one recognizes in garbage crematories of the present type are:
1. — That the process of destructive distillation, rather than
oxidization, has been resorted to.
2.^That apparently no lower-limit temperature has been re-
garded as a standard by the builders of such apparatus,
although it is absolutely necessary to maintain a tem-
perature of more than 1 250° fahr., in order to insure
the combustion of the hydro-carbons and the dissociation
and oxidization of objectionable chemical compounds.
3. — That the usual method of feeding and stoking precludes the
possibility of obtaining anything like a regular tempera-
ture in the furnace, the temperature rising and falling
with an amplitude of probably 800°, and sometimes fall-
ing as low as atmospheric temperature.
4. — That the high temperature is usually at the wrong end of
the furnace, namely, that farthest from the outlet, and
as long as this remains there can be no hope of dealing
successfully with the material in a sanitary manner. At-
tempts to overcome this difficulty have been made by
Papers.] DISCUSSION ON MUNICIPAL REFUSE DISPOSAL 43
following the ideas of Mr. Charles Jones, of London, who, 3tr. Leask.
in 1885, introduced a fume cremator between the furnace
and the chimney. This was a palliative rather than a
cure, and' while it succeeded in reducing the nuisance to
some extent, it only went half way.
5. — Another error, in certain types of garbage cremators, is
made in the environment of the burning mass. Water-
jacketed furnaces are absolutely unsuitable for burning
garbage or other material high in hydro-carbons. In
such a furnace, flame is no sooner generated than it is
extinguished by absorption, due to contact with cold sur-
faces, or by radiation. No one would think of hatching
eggs out in an ice box.
6. — Finally, restrictions as to the amount of organic matter re-
maining in the ash after cremation do not seem to be
imposed upon the builders of such apparatus, nor have
such apparatus succeeded satisfactorily in eliminating
the organic matter from the ash.
Table 1 is likely to give a very erroneous impression as to the
quality of the refuse collected in Great Britain, That the author
does not rely on the figures given in this table, is quite apparent. His
estimates of the character of the refuse in various cities, as given in
Table 10, prove that the conditions at the plants he visited did not
correspond with the figures in this table. Hutton's figures as to the
percentage of coal, coke, breeze, and cinder are much too high,
even for mid-winter. Mr. Codrington's figures appear to be much
nearer to the actual conditions, while those of Mr. Eussell, giv-
ing 64.53% for coal, coke, breeze and cinder, are not justified by the
results which he has obtained at the Shoreditch plant, the operation of
which he directs. The figures for Torquay appear to be inverted, and,
if inverted, would more fairly represent the conditions existing in
that town and in similar towns along the south coast of England and
in suburban districts.
That there is a marked similarity between the refuse collected in
Great Britain and that collected in New York is undoubted, and the
difi'erence relates more to character than to calorific value. The
speaker agrees with the author that there is probably more moisture
in refuse, as collected in Great Britain, than in refuse collected in the
Borough of Richmond, biit it is in a different form. In the Borough
of Richmond the moisture is principally contained in the garbage,
while in Great Britain the ash, as a rule, contains quite a large per-
centage of water, and it must be remembered that, in this form, it is
more easily attacked than when carried in the structure of material
such as garbage.
44 DISCUSSION ON MUNICIPAL REFUSE DISPOSAL [Papers.
Mr. Leask. There is a similarity, also, between the refuse collected in many-
cities on the Continent of Europe and that collected in the United
States. It has been stated that the refuse collected in Berlin has a
calorific value of about 2 000 B. t. u., while at Frankfort it has a
calorific value of 4 350 B. t. u. ; the refuse collected in Vienna is
stated to contain about 3 000 B. t. u., and that at Kiel somewhat less.
The refuse collected in Paris has been analyzed frequently, and has
been variously stated to contain from 3 600 to 5 400 calories.
It should be noted that the chemical analysis of the refuse at Kings
Norton was made of refuse collected in winter. In the spring, three
years later, another analysis was made, and the refuse was found to
contain 4 300 B. t. u., In summer, however, the calorific value could
not be much more than 3 000 B. t. v..
It might be interesting to give the calorific value applied to various
classes of refuse by German scientists, in order that a comparison may
be made between that part of Table 1 devoted to that subject and
the values ascertained by Mr. Welton :
Vegetable matter ... 2 165 B. t. u.
Bones 540 "
Paper 3 950 "
Sawdust 5 750 "
Wood 6 280
Straw 5 400 "
Coal, coke 9 380
Hair 1 620
Eags 3 600 "
It will be seen that the calorific value of vegetable matter corre-
sponds very closely with Mr. Welton's figures, while that for coal, coke,
etc., is somewhat higher, and that for rubbish (composed of paper,
wood, rags, etc.) is appreciably lower.
In order to make a comparison of the refuse collected in the Bor-
ough of Kichmond and that collected in the London residential dis-
trict, containing some stores, and a suburb of one of the large
provincial towns, the speaker's firm, by the courtesy of the city en-
gineers, made a number of analyses of the refuse as collected in the
Metropolitan Borough of Stoke Newington and Kings Norton, near
Birmingham. This refuse was sorted by hand into four classes:
1. — Garbage ;
2. — Coal, coke, cinders and fine dust, including fine inseparable
vegetable matter;
3.— Eubbish;
4. — Large incombustible matter, such as tin, bottles, etc.
These analyses were made at a period corresponding to the critical
month in Richmond, that is, September and early October. The volume
Papers.] DISCUSSION ON MUNICIPAL REFUSE DISPOSAL 45
of the refuse at Stoke Newington worked out to about 4 cu. yd. per Mr. Leask.
ton of 2 240 lb., and it contained on an average : 34.43% of garbage,
42.92% of coal, fine dust, etc., 15.4% of rubbish, and 7.35% of glass,
metals, etc. The refuse had averaged 4 cu. yd. to the ton for about
five months, and presented somewhat similar characteristics during
this period. At Kings Norton the refuse had a volume of about 3.75
cu. yd. per ton, and carried 39.5% garbage, 45.4% coal, fine dust, etc.,
9.3% rubbish, and 5.2% glass, metals, etc. Taking September alone,
there was 49.37% garbage, 38.80% coal, coke, etc., 7.73% rubbish,
4.28% glass, etc., from which it can be seen that the percentage of
garbage is even higher than that collected in the Borough of Richmond
for that month. It is not suggested that the foregoing figures are ab-
solutely accurate, but merely the result of an honest endeavor to ascer-
tain the make-up of the refuse. The results obtained with the refuse
at Kings Norton agree very well with the balance sheet, as shovsm in
Table 9, as to evaporation and combustion-chamber temperature. In
September the evaporation was somewhat higher than that calculated in
the balance sheet, that is, more than 1.25, actual, in ordinary work, and
the average temperature in the combustion chamber about 150° higher.
The speaker's make-up of a balance sheet would differ slightly in that
the radiation loss would not be as high, while there would be a some-
what lower percentage of tmburned carbon in the clinker and ashes,
but probably a greater loss in moisture in chimney gases. As the
average combustion-chamber temperature and evaporation in winter
and spring are considerably higher than the foregoing, it can be seen
that, in British refuse, as well as that under discussion, there is a
considerable seasonable variation.
The practical tests, as given in Table 8, demonstrate clearly that
the material is burnable, and the results obtained are such as might
be expected when burning material in such a crude furnace, and pre-
clude all doubt of obtaining satisfactory temperatures with a prop-
erly regulated and heated air supply.
Based on the results obtained with summer refuse in England,
Messrs. Heenan and Froude, Ltd., of Manchester, who have been en-
trusted with the plant for New York City, specially designed and
erected a plant in Vancouver, B. C. This plant has certain de-
partures from their standard type. It is now in successful operation,
and, of the refuse collected in that city, it is destroying more than
50 tons per 24 hours, at suitable temperatures, without the aid of
supplementary fuel, and with an excellent residual. The refuse burned
is very poor in quality, due to the presence of considerable quantities
of wood-ash and moisture. The difficulties of obtaining high tem-
peratures with this material have been overcome by checking the
quantity and increasing the temperature of the air supply. Figures
in detail as to the results are not yet at hand, therefore they cannot
46 DISCUSSION ON MUNICIPAL REFUSE DISPOSAL [Papers.
Mr. Leask. be given here. The cost of destruction is 36,1 cents per ton, includ-
ing the salaries of two engineers who look after the pump, boiler, fan,
etc. During the first week the plant was put in operation, it sur-
passed the guaranty, which is unusual — the men being untrained — and
better results may be expected in the course of time.
The utilization of the steam and clinker resulting from the de-
struction of refuse is by no means the only offset to the cost of burn-
ing. The most important offset is the reduction of the cost of collec-
tion, for a modern plant may be placed in the center of a city or
residential quarter without fear of nuisance to the neighborhood.
This means a great reduction in the cost of collection and transport.
Numerous instances can be cited supporting this: in the Metropolitan
Borough of Stoke Newington, previously mentioned, two 45-ton units,
each with 200-h.p. boiler and the appurtenances thereto, a clinker-
crushing and screening plant, has been erected in the middle of the
Borough, at the rear of the Town Hall, and surrounded on all sides
by three and four-story dwellings of a good class. Notwithstanding
the fact that the interest and sinking fund on the capital outlay, the
repairs, maintenance, and labor charges have to be added to the cost
of disposal, the cost of collection, transport, and final disposal is now
lower than it was prior to the erection of the plant, and this in spite
of the fact that, as yet, no use has been made of the steam generated,
which is equivalent to about 175 k.w. per hour from one unit; also
exclusive of the sale of clinker, which has been contracted for on a
profitable basis. The same conditions apply to Woodgreen, London,
where the plant is also critically located, and at Rathmines, Dublin,
where a saving in coal of $2 000 per year (in addition to the saving
in cost of collection and transport) has been made, and where, in the
past, the power has been utilized without relying on storage batteries.
Now that storage batteries have been installed, the saving in coal, as
shown by the working during the past few months, will be more than
$5 000 per anum. This is the more remarkable as the quantity of ref-
use to be handled is less than 35 tons per day.
Table 9 gives the average temperature which may be expected in
the combustion chamber at various seasons; it gives no idea, however,
of the lowest temperature which may occur. When burning Septem-
ber refuse on the standard British furnace with air heated to, say,
250° fahr,, the lowest temperature would be near, if not actually be-
low, the limit of 1 250°, momentarily. To insure the temperature
always being above this lower figure, it is absolutely necessary to in-
crease the temperature of the preheated air, to control the air supply
very carefully, and, further, to increase temporarily the temperature
of the air entering the furnace immediately after a fresh charge.
Fortunately, this can be effected by taking the heat out of the clinker,
just withdrawn from the grate, prior to charging. All these points
Papers.] DISCUSSION ON MUNICIPAL REFUSE DISPOSAL 47
have been given special attention in the case of the plant for New Mr. Leask.
York City.
British destructors have been designed in accordance with the
principles mentioned by the author, but it has been by progressive
steps, and after many failures. The various steps in the concep-
tion and improvement of refuse furnaces, as made in England, may
be traced as follows:
1. — The attempt to burn refuse in or under shell boilers;
2. — The building of a fire-brick lined furnace, or Dutch oven,
operated by natural draft;
3. — The introduction of the fume cremator;
4. — The abandonment of the fume cremator and the introduc-
tion of forced draft;
5. — The preheating of the air supply;
6. — The use of a continuous furnace chamber, containing a
number of grates with divided ash-pits;
7. — Suitable ventilation of the building;
8. — Methods of handling the clinker and recovering the heat
contained in it.
With regard to the cost of operation, it is possible, with a large
plant, to reduce the labor charge, part of the work being effected by
mechanical means. It must be remembered, however, that the feeding
of the furnace is only one of three operations necessary in the work-
ing of the plant : First, there is the introduction of material into
the furnace, which may be done mechanically; the other two, which,
however, do not appear to be susceptible to mechanical operation, are
the stoking and spreading and the final cleaning out of the mineral
residual from the grate.
The speaker's firm has attempted to solve this problem, and after
many failures has at last succeeded in devising a machine which will
handle all classes of refuse and will feed the refuse in any desired
quantity. Extended trials of such an apparatus have been made at
one plant, and it will soon be installed in some city. The system to
be adopted for charging depends on the specific gravity of the material
to be dealt with and the size of the plant.
The speaker has had the opportunity of examining the refuse in a
number of large cities in the United States, and is strongly of the
opinion that the combined refuse of most cities can be destroyed by
fire at suitable temperatures, without the aid of supplementary fuel.
This brings up another phase of the question which has been
mentioned by Mr. Eetherston, namely, the collection of the refuse.
The adoption of a system of a single collection of refuse, combining
the ashes, rubbish, and garbage, cannot be urged too strongly. It is
impossible to get complete or satisfactory separation. It is a question
48 DISCUSSION ON MUNICIPAL REFUSE DISPOSAL [Papers.
Mr. Leask. of public health, rather than profit. The single collection costs less
tc make. The mixing of thd refuse retards decomposition, the ashes
acting as a deodorant by absorption, and it provides a wherewithal in
calories to cleanse the mass of its impurities, and, when burned, leaves
a marketable residual in the form of clinker. If advantage be taken
of the heat generated by combustion (and here it should be noted
that, whatever the material may be, when it is burned at suitable
temperatures there is always utilizable heat), there is placed at the
disposal of the authorities another valuable residual in the form of
steam, the best uses for which are those giving a large load factor,
such as pumping — sewage or water — or electric traction. Lighting
alone is not a satisfactory outlet. The question of collection and dis-
posal of refuse in the United States to-day appears to be in the state
that it was in older countries some years ago, that is, in the hands of
contractors. It has been abundantly demonstrated that the only satis-
factory method is for the municipalities themselves to undertake it.
Where this has been done, and where refuse destructors form a part
of the scheme, it has been followed by a noticeable decrease in the
death rate. Why should not one of the richest coimtries in the world
forsake the problematical gain arising from reduction, and regard the
question from a purely public health standpoint, as has been done in
older countries, even in backward Russia?
The whole question is purely one of combustion, and, generally
speaking — provided the moisture contained in the material is not ex-
cessive— refuse containing 2 000 B. t. u. per lb. will cleanse itself.
The great difference between the combustion problem as applied
to coal and refuse is this : When dealing with coal one has a material
which is comparatively low in ash and requires about 20 to 24 lb. of
air per lb. to burn it in a practical and satisfactory manner, whereas
refuse is high in ash, and the air required is only from 4 to 5 lb. per
lb. The difficulty, therefore, is to find a small quantity of carbon in
so large a bulk, with the minimum quantity of air. To effect this
one must look to the distribution and the temperature of the air sup-
plied, the intensity of the draft, and the environment of the burning
mass. It is, therefore, wholly an engineering proposition.
The speaker must again congratulate the author on the service he
has rendered to engineering science in general and contracting engi-
neers in particular.
Vol. XXXIV. JANUARY, 1908. No. 1.
AMEEICAN SOCIETY OF CIVIL ENGINEERS.
INSTITUTED 185 2.
PAPERS AND DISCUSSIONS.
This Society is not responsible, as a body, for the facts and opinions advanced
in any of its publications.
THE EEINFORCED CONCRETE WORK OF THE
McGRAW BUILDING.
Discussion.*
By Messrs. Guy B. Waite and E. P. Goodrich.
Guy B. Waite, M. Am, Soc. C. E. — Had the McGraw Building Mr. Waite.
been designed ten years ago, it would not have been built of reinforced
concrete. Few engineers at that time had sufficient confidence to
undertake the experiment, and the local building laws did not permit
it. Even more recently than this, nearly every important architect
in the vicinity would have refused to listen to an argument for using
concrete in a building in which there was to be heavy vibration, as it
was only considered fit for light, cheap buildings.
At that time, even engineers were afraid to speak in favor of con-
crete for general building purposes, for fear of becoming unpopular.
One who dared engage in concrete building construction had to en-
dure the humiliation of seeing some of his former friends pass quietly
to the opposite side of the street when they saw him, in order to avoid
meeting one who was engaged in an immoral business, and who was
just escaping the meshes of the law. The change in public opinion,
with regard to reinforced concrete, has been brought about purely by
the merits of the construction.
About ten years ago the Building Department of New York City
inaugurated standard tests for concrete constructions to be used for
fire-proof floors. All constructions for floors had to be submitted to a
4-hour fire test, at an average temperature of 1 700° fahr. They
were to be loaded with 150 lb. per sq. ft. on a full-sized floor not less
* Continued from December, 1907, Proceedings.
50 DISCUSSION ON REINFORCED CONCRETE BUILDING [Papers.
Mr. Waite. than 14 ft. long. Immediately following the fire — the material being
still red-hot — a regulation stream of cold water was to be thrown on
the construction, with a pressure of 60 lb. per sq. in., for 10 min.
The construction was then to withstand a distributed load of 600 lb.
per sq. ft."
During the five years following the inauguration of this test, about
twenty-five concrete constructions withstood it successfully. By this
time some of the public had been convinced that concrete possessed
merits, as a fire-proof material, but did not dare to speak out; while
others feared that it had some merits, and set out to kill it. Quite
successful obstacles were placed in its way, by the Board of Insur-
ance Underwriters, who fined it; by codes of law, which practically
ruled it out; by labor unions, who dictated by whom and how it should
be made; and by politicians, whose interests were generally in other
directions.
Interest was finally awakened by the favorable showing made by
concrete in some of the great fires on which a few honest reports were
made by eminent engineers, and since that time concrete constructions
have gained rapidly in popularity.
It was only about four years ago that the speaker secured, from
the Department of Buildings of New York City, the first permit ever
granted in the Borough of Manhattan for a concrete building, in-
cluding concrete wall construction. All who are interested in the
advancement of reinforced concrete must feel indebted to Professor
Burr for giving his name and influence to this cause.
The McGraw Building was undoubtedly made in reinforced con-
crete because it ofi^ered the best construction to withstand the
peculiarly heavy work of a printing house; and because it gave the
safest fire risk. The National Board of Fire Underwriters, some two
years ago, recommended a minimum rate of insurance on similar con-
structions, and, from recent inquiry of the Local Board of Fire Un-
dervtrriters, it is learned that even this august body has at last reached
a point where a similar action is under consideration.
As a fire risk, concrete structures offer the best possible invest-
ment, either for individuals to carry their own risks, or for insurance
associations to make a specialty of these constructions. Such under-
takings would be the safest and most profitable kind of insurance
ventures.
Concrete is superior to burned clay, not because it is more fire-
proof, but on account of its superior elasticity under the stress due to
fire and water. Some years ago the speaker constructed, entirely of
cinder concrete, a test house, 14 by 14 ft. and about 12 ft. high, with
walls 12 in. thick, and with a ceiling only IJ in. thick. In various
tests conducted by the Department of Buildings in that house the
ceiling was submitted to four separate series of fire tests.
PLATE II.
PAPERS, AM. SOC. C. E.
JANUARY, 1908.
WAITE ON
REINFORCED CONCRETE BUILDINGS.
Fig. 1.— Cinder Concrete Test House, After Fourth Fire
Fig 3.— Stone Concrete House, with Test Load,
After Four-Hour Fire Test.
Papers.] DISCUSSION ON REINFORCED CONCRETE BUILDING 51
When this structure was torn down, to make way for dock im- Mr. Waite.
provements, this IJ-in. ceiling was examined by an engineer from the
Department of Buildings of New York City, and by Professor Wool-
son of Columbia University, and was found to be in good condition,
the fire having affected scarcely ^ in. on its under side, and this was
due to the first fire.
While reinforced concrete has been demonstrated to be superior
in many respects to other forms of fire-proof construction, it has
forced its way to the front principally on account of the economy it
has effected.
The parts of a building in which it is best adapted must be deter-
mined largely by the engineer's experience. Sometimes this experi-
ence is paid for very dearly, and forms a secret chapter in his
biography.
Local conditions often alter circumstances to such an extent that
a kind of construction which might be erected in one locality at a
profit would become a loss in another locality a short distance away.
As the relative prices of built steelwork and concrete per unit
section are about as 65 to 1, and the relative working capacities in
compression (16 000 to 500) are about as 30 to 1, it is evident that,
other things being the same, the more concrete is substituted for steel
in compression, the greater is the economy.
Where heavy loads are to be carried, concrete will be found highly
advantageous; conversely, where small loads are carried, it will have
little advantage. Keeping this fact in view, one would expect to find
the greatest economy in using concrete for column supports and floor
constructions — the heavier the construction, the greater the economy.
The great barrier to using concrete for columns is the impractical
size necessary when more than a few stories are required. Leaving to
others the discussion of the rationality of the combination of con-
crete and steel in the columns of the McGraw Building, the speaker
considers this form of construction siiperior to anything heretofore
done in reinforced columns.
The column is reduced to a reasonable size, and is made safe
against accidents. The positive dead loads from the building are
carried by positive steel supports, while the doubtful superimposed
floor loads are adequately provided for by the more questionable form
of concrete reinforcement.
The certainties are balanced one against the other, and the un-
certainties are also brought to face each other. Although columns of
this form are not directly the cheapest, the speaker believes them to be
the most economical, all things considered. Columns of this form
are adapted to much speedier erection than the cheaper reinforced
concrete, and are absolutely safe during erection; they also allow
as good a monolithic connection of the column with the floor as that
52 DISCUSSION ON REINFORCED CONCRETE BUILDING [Papers.
Mr. waite. obtained in other reinforced forms. The column forms, with the steel
as a gxiide, cost less than where they are made as independent struc-
tures.
As pointed out by the author, the construction of the forms is
probably the greatest problem in the practical construction of rein-
forced concrete. Almost every beginner in this field has arrogant
confidence in his ability to eclipse everything previously done in the
way of perfect centering. It is only necessary to watch such an one
and see a second scheme in his second job, a third scheme in his third
job, and so on, imtil he becomes a meek plodder along the tow-path
of experience.
A discrimination should be made between centers or forms de-
signed for a building, and a building designed for the forms. Forms
made to fit a special building may cost several times as much as those
with which a standard building might be made. The cost of center-
ings may be reduced about in proportion to the standardization of
the building. Many useful schemes for systematizing the general
construction of centerings have been invented, and many of these
have simplified the problem so that the main cost is in taking down
and putting up the forms.
Most of these centering schemes are used for rough concrete work,
where the surface is to be plastered afterward; but when finished sur-
faces are to be produced, the cost of centers is more than doubled. If
the mechanic trained to do finished-center work be told to make rough
standard centers, he will spend nearly 7i hours carefully getting
ready to do work which would take the other man J hour; conversely,
the rapid standard-center man if put on perfect-center work, would
do in i hour what would take the perfect-center man about 7i hours
to undo and do over again. False conceptions and misrepresentations
on the part of competitors in concrete work have led them into bitter
warfare by presenting owners with what they term "finished surface"
free of cost. Is it not possible to conceive a method of trying uni-
formly rough surfaces instead of uniformly smooth surfaces, as a
help toward solving the problem of centers ?
The indirect method may be used to cheapen centers, that is, con-
structions may be used which do not require the expensive centering
necessary in ordinary forms of reinforced concrete. If such construc-
tions de not advance the total cost by increases in other directions,
there will be a net saving. As is evident, the forms or centers for
ordinary reinforced concrete must be sufiiciently heavy to maintain
a perfectly , independent structure under the tendency to warp and
deflect, due to the fact that they are alternately wet and dry, and also
on account of the heavy load of the concrete. Where a steel skeleton (such
as the columns in the McGraw Building), maintains the construc-
tion lines, one may use for centers material which is much lighter, and
PLATE III.
PAPERS, AM. SOC. C. E.
JANUARY, 1908
WAITE ON
REINFORCED CONCRETE BUILDINGS.
I^^^^IP*^^
i^^m
■
w
9
^S^k
^^^^^^Kl
p
I
]
K
^. ^ ..
p
H^^^i
wK^^^^^
^^
Bv^^>
E-
"■^^^^
^^^^■hL
mKi
*'i
'"""^■^-^^i
Fig. 1. — The Bonwit-Teller Building
Fig. 3.— The Salvation Army Warehouse.
Papers.] DISCUSSION ON REINFORCED CONCRETE BUILDING 53
more easily worked and handled than with ordinary reinforced con- Mr. Waite.
Crete.
The author does not describe the wall construction of this build-
ing, but the speaker believes it to be of some form of reinforced con-
crete. In wall construction, the conditions are very different from
either column or floor construction. In both columns and floors, con-
crete makes a saving in steel, but, in wall construction, this element
of saving does not enter. Further, in monolithic wall construction
two forms must be kept plumb, but in floors only one form is re-
quired, and gravity helps to hold this in place. The speaker, with the
very best of assistants, after finishing several buildings having com-
plete concrete wall construction averaging 8 in. thick, concluded that
the cost of the concrete in such wall construction was of small con-
sequence and could be safely neglected in totaling up the entire cost
of the wall. In factory construction, where there are practically no
walls except panels under windows, no such difficulties are en-
countered as in dead wall construction.
Nothing is stated definitely by the author concerning the character
of the steel used in the floor construction, other than that round rods
were used. The kind of bars and the character of the steel in them
seem to command a great deal of attention at present. The only
logical conclusions that can be drawn from the claims of the big
grist of deformers (with increased capacities for each new deforma-
tion in their rods) is that they are developing the art toward a state
where (according to claims) practically nothing but bond and grip
will be required, and steel for tension, etc., as now designed, will be-
come of little consequence.
In referring to some recent constructions which the speaker has
^xecuted, the only excuse he has to offer for so doing is that such
improvements have come after quite a lengthy experience in general
steel and reinforced concrete construction, and, being a product of
natural evolution, they belong to the general scheme of development
toward something higher. The speaker's experiences have been unlike
those of many engaged in reinforced concrete construction, because,
m most cases, he has had to contend with the conditions existing in
crowded^ parts of large cities, where space for storing materials and
performing work is extremely limited, and where great rapidity of
erection is necessary; and, on account of the extra height of build-
ings, safe construction must be considered.
Having been fundamentally trained in steel construction, followed
by the fire-proofing of the steel; and subsequently having pursued
general reinforced concrete construction, the speaker was forced to
consider the merits and demerits of the combinations of these three
factors in building construction for the conditions found in large
cities.
54 DISCUSSION ON EEINFORCED CONCRETE BUILDING [Papers.
Mr. Waite. The Safety and the speed of steel construction were apparent, and
the advantages in the use of concrete for the protection and fire-
proofing of steel were well demonstrated. Then followed the combina-
tion of steel with concrete (formerly used for fire-proofing), and this
developed into a system which possessed all the merits of the steel
skeleton construction and the advantages of reinforced concrete. In
this system (known as System "M," in its order with other systems)
there is required only from 35 to 40% of the steel necessary for the con-
ditions in which the steel does all the work. The concrete — which
must be used for fire-proofing — is made to do the remainder. The
light steel frame is run up ahead of the concrete, in the usual manner
for steel frames, and is made strong enough to take all tensional and
shearing stresses in the subsequently reinforced construction formed
by the steel and concrete. The combination forms a truly reinforced
structure.
Work can be done on several stories simultaneously, as in other
steel construction. The necessary forms are simplified, as compared
with those required in most reinforced concrete constructions, on ac-
count of the assistance given by the steel frame. Within the last two
years, some twenty buildings in the vicinity of New York City have
been constructed by this system.
From January 1st to April, 1907, while the McGraw Building was
being erected, three buildings in that vicinity were constructed in
which the floors were of this form of construction, namely: The
Bonwit Teller Building,* at 15 and 17 West Thirty-fourth Street,
shown by Fig. 1, Plate III; the Salvation Army Warehouse,! at 533
and 537 West Forty-eighth Street, shown by Fig. 2, Plate III ; and the
Strack Building, at 214 and 220 West Twenty-third Street.
In these buildings steel columns carry the entire loads, but, where
conditions permit, a light steel frame, similar to the construction used
in the McGraw Building, carries the dead floor loads.
The general form of the steel in this combined column construc-
tion is shown by Fig. 1. It is made of channels or similar sections
disposed centrally with respect to floor beams and girders, and the
separate steel members are connected at the corners. The speaker
has found this to give a very simple and effective steel skeleton which,
he believes, affords ample means for the proper combination of the
steel and concrete.
Some months ago, in building a garage for the use of his family,
at Whitestone, Long Island, the speaker concluded to make the entire
building of reinforced concrete in order to demonstrate the economy
of a new form of construction suitable for a small number of laborers.
The building is 40 ft. long and 20 ft. wide, and has two stories, and
* Engineering Neirs, April 25th, 1907.
+ The Engineering Record, June '23d, 1907.
PLATE IV.
PAPERS, AM. SOC. C. E.
JANUARY, 1908.
WAITE ON
REINFORCED CONCRETE BUILDINGS.
Reinforced Concrete Garage at VVhitestone, Long Island
Papers.] DISCUSSION ON REINFORCED CONCRETE BUILDING
55
an attic. The walls consist of a series of 12 by 8-in. reinforced Uv. waite.
pilasters, spaced 5 ft. apart between centers. Between these buttresses,
and erected simultaneously with them, there are concrete blocks, 3 in.
thick and 12 in. wide. In the lower story the blocks are flush with
the outside of the pilasters, and in the second story they are kept back
from the front to give the effect shown in the photograph, Plate IV.
m
jSi
W^
I
-^.
SYSTEM "M" COLUMN
Fig. 1.
The floors were reinforced with 4 by T^-in. steel beams, resting on the
pilasters, and having shear bars extending up from holes in the webs
of the beams. One handy man and two laborers constructed the
foundations and all the walls and floors in about 8 weeks. The walls
were run up several feet above the second floor in order to make a
full story of the attic.
E. P. Goodrich, M. Am. Soc. C. E. — The speaker's connection with Mr. Goodrich,
the McGraw Building, in a supervisory capacity, during the major
portion of its design and construction makes Professor Burr's descrip-
tion of special interest to him. In a few particulars, that description
may be somewhat amplified, for the sake of noting additional points
of interest.
The power plant for the building is located in a sub-basement
situated in the southwest corner. Consequently, the columns in that
portion of the building are somewhat langer than the others and ex-
ceed the dimensions given in the paper by 12i ft., making the length .
56 DISCUSSION ON REINFORCED CONCRETE BUILDING [Papers.
Mr. Goodrich, of the longest column 172 ft. It may also be of interest to note that
the "reinforcement" in the first length of one of these columns weighed
14 050 lb.
The windows on the sides and rear of the building are of wire-glass
in metal frames, so that practically the only possible additional device
which could be added to give security against fire, would be a com-
plete automatic sprinkler system. In consequence, the McGraw Build-
ing is one of the best in the city, as far as insurance conditions are
involved, and carries a very low rate for both the building and the
contents.
The column spacing was determined primarily by the dimensions
of modern printing presses, nearly half a score of which are now in
operation on several of the upper floors of the building. This fact
brought about the use of rectangular floor bays, while a more nearly
square arrangement would have been slightly more economical, had it
been possible to design the building in that way.
Of the several new features in the building, of course, the column
design is the most unusual. While the whole arrangement, as finally
worked out, proved highly satisfactory, from a construction point of
view, it may be open to some adverse criticism, from a solely economic
standpoint. As shown by Mr. Douglas, a design for purely structural
columns would have cost less money, and Mr. Stern suggests that, even
when fire-proofed, such columns wovild have been smaller than those
used. Plenty of evidence has been adduced from the San Francisco
conflagration to show that no comparison can be made between struc-
tural columns, however well "fire-proofed" in the usual manner, and
such columns as are used in the McGraw Building. No comparison
is fair unless this superiority to resist fire is capitalized. On the
other hand, columns of the Considere type likewise possess this good
quality, their principal drawback, under such conditions, being their
size. It may be of interest to state that, early in the history of the
design of this building, the speaker caused to be prepared a typical
column of the Considere type, based on the accepted stress require-
ments of the New York City, Manhattan Borough, Building Regula-
tions at that time. The columns, of course, were circular in section,
with a diameter in no case greater than the diagonal of the corre-
sponding square column of the Burr type, finally vised. The estimated
cost of the Considere column, on a conservative basis, showed an ap-
parent saving in its favor of approximately $10 000 for the whole
building.
Two other small objections to the Burr column were also discovered,
which wore almost entirely obviated during the progress of the work,
and could be entirely remedied in future designs. The wide faces of
the angles in the lower stories, and the wider expanses of some of the
splice-plates, made necessary a special wrapping of wire or wire lath
Papers.] DISCUSSION ON" REINFORCED CONCRETE BUILDING 57
to hold the fire-proofing concrete in place ; and the extreme rigidity Mr. Goodrich,
of the column steel, made necessary a much more careful adjustment
of the forms than is usually required for reinforced concrete build-
ings. In most cases, the less rigid reinforcing rods are given slight
eccentricities, which do not affect their efficiency seriously, and are
thus made to accommodate themselves to small variations in the spac-
ing of the forms, and thereby save some labor cost. This latter possi-
ble defect of the rigid reinforcement may even be considered a ' real
virtue, in the eyes of some people.
The speaker is aware of really very few reliable tests of reinforced
concrete columns, and of none which possessed anything like the per-
centage of longitudinal steel found in those of the McGraw Building.
Some time ago, the speaker arranged for a series of tests on specimens
designed after the Burr type, and of practically full size, but, un-
fortunately, the results have not yet been secured. In this, it is well
to note a fact to which Professor Morsch, of Zurich, calls attention,
in his "Eisenbetonbau," that the efficiency of longitudinal rod rein-
forcement decreases with the increase of the percentage used, at least
up to 4%, and that no one knows how larger amounts will act. It is
thus incumbent upon designers to exercise great care in selecting
working stresses for concrete columns possessing considerable longi-
tudinal steel, as the field is absolutely unknown at the present time,
and some serious trouble may result for inexperienced designers who
follow rules blindly.
Another point to be noted is the fact that most experimenters on
concrete columns have concluded that the concrete appears to carry
much the larger percentage of the load until it has reached a stress
far above the usual allowable working one, when the steel comes into
more pronounced action. Of course, this conclusfon is based on com-
putations involving an assumed modulus of elasticity of the steel and
the observed stresses and strains of the column. The distribution of
stress, above described, is probably due to the fact that the stress-
strain curve for concrete is not a straight line, thus demonstrating the
existence of a variable modulus of elasticity. From these facts, it
might seem to be more rational to reverse the condition as to the dead
and live load carrying capacities of the steel and concrete in the Burr
column, and require the concrete, at say 750 lb. unit stress, to carry
all the dead load and then add enough steel in structural form, if so
desired, to carry the total or reduced live loads.
Another item of design in the McGraw Building to which special
attention was paid, was the connection between the reinforcing rods
and the column steel. This was worked out so effectively that the
steel erectors of the columns often attached, to any convenient point
of the beam reinforcement, one end of the turnbuckle which they used
for plumbing the column sections. In no other reinforced concrete
building within the speaker's knowledge could this be done.
58 DISCUSSION ON REINFORCED CONCRETE BUILDING [Papers.
Mr. Goodrich. With such rigidity of column steel and its firm connection with
the beam rods, the best method of beam design would seem to be that
of cantilevers or continuous beams throughout, instead of simply sup-
ported members. Such an arrangement of the steel in a concrete
beam has the following advantages:
Maximum shears occur at points where maximum moments are
found, and, in consequence, where most steel is placed.
Not as much steel is found near the bottoms of beams, where it
would be exposed to the most trying effects of fire.
Such a method of design obviates the tendency to sharp deflec-
tions near the supports, with the resulting probability of
the occurrence of cracks at points where the shear is the
greatest.
Such design gives most resistance against the type of failure
observed in impact experiments.
There is also less likelihood of the displacement of reinforcement,
because it is in view during the greater part of the process
of concreting.
All beams and girders throughout the McGraw Building were de-
signed as fully continuous, or restrained, even where supported in the
outside columns and walls. The drawings show twice as much steel
over tlie supports as in the centers of the spans, and, since the factor
used in connection with the moment at the latter point is xjj, according
to the requirements of the Building Code, the factor for the supports
is only i. Thus it is seen that, when compared with ^^^, and ■^^.
the theoretically correct vakies, more than twice as much beam and
girder reinforcement was used as theory would dictate. This extra
material was used iji a literal compliance with the anomalous wording
of the New York Building Code. A comparison of this building with
numerous others has led the speaker to the conclusion that the re-
quirements therein contained are rarely complied with literally, and
that this faulty requirement of the code has been the real cause of
much poor work.
To the speaker, no reason is apparent for using, over points of
support, more steel than enough to satisfy the theoretical moment
formula, with a coefficient of y\. When that amount is used in that
way, only half as much, of course, is theoretically necessary in the
lower part of a beam at its center, while the building requirements
specify as much as would be indicated by a coefficient of r^, which is
even more than is needed in the upper part of the beam over a support.
Some slight argument may be advanced for using as much steel
below as above, in the two locations, from the fact that eccentrically
placed partial loads on continuous members resting on perfectly mov-
able supports, subject the members to maximum positive and negative
moments which are much larger than those produced by a continuous
Papers.] DISCUSSION ON REINFORCED CONCRETE BUILDING 59
load, as usually considered. This fact has often led the speaker to Mr. Goodrich,
recommend a partial concession to the older ideas of design, and to
use equal amounts of steel over the supports and at the centers of
spans, determining this quantity by the coefficient, tV- This distri-
bution allows of an economical design for, and method of handling,
the rods; it meets practically all the requirements of partial loads,
and, at the center of the spans, uses within 20% of the quantity of
steel required by the New York Building Code, with 100% better dis-
tribution, as far as prevention of cracks is concerned.
The reinforced concrete beams and girders of a monolithic con-
crete building are not beams and girders at all, in the sense of the
wooden and steel ones in the older types of structures, which simply
rest on brackets and have ample opportunity for motion in each joint.
Until cracks have formed, the concrete beams are really extended
brackets on the columns and other members, and should be designed
as such. The early workers with reinforced concrete were influenced
too largely by the old type of structure, and few designers have even
yet grown into the true spirit of the newer material.
Thus it has transpired that the McGraw Building has a floor con-
struction which is rated far below its true safe carrying capacity.
Were any floor loaded to failure, the latter would probably take place
by shear, or rather diagonal tension. In relation to this, however, it
must be stated that the speaker never has understood why those in
actual charge of the design of the reinforcement (other than the
author of the paper), invariably used an odd number of rods to resist
tension. By so doing it is impossible to bend upward the same number
of rods at each end of a beam to assist in resisting shear, so-called.
Thus, Ave rods might be used in a given case for tension reinforce-
ment. Three could be bent upward at one end, but then it is practicable
to bend up only two at the opposite end of the adjoining beam without
causing a congestion of steel over the support. If the two bent rods
were just sufficient to assist the shear, the three rods at the other end
would give 50% better efficiency at that end; and 20% more resistance
would have been secured at the weaker end by using six rods of
smaller individual (but aggregating the same total) area, and bending
up three rods at each end.
The floor forms were designed with especial care. They were
collapsible in type, and were erected in an exceptionally substantial
manner, so as to be capable of serving as platforms from which to
erect the structural work of the columns. The determination, after-
ward made, to use the central tower for erection purposes, rendered
this special reason for heavy forms unnecessary, but their value was
repeatedly shown for other reasons, and the speaker is decidedly of the
opinion that a little extra material in excess of that sometimes seen,
is of real economic advantage. The forms were designed by Mr. J. G.
60 DISCUSSION ON REINFORCED CONCRETE BUILDING [Papers.
Mr. Goodrich. Ellendt, and were all built in a special shop, hauled to the building
site on trucks, and the whole truck-load hoisted by the central derrick
in a single operation and set practically in place. The speed actually
attained in erecting the building, shows how well the form work was
prepared and carried on, because that work is the crucial part of the
erection of all concrete work. Matched and dressed material was used
throughout, always well coated with oil, so as to obviate the necessity
of special surface finish if possible. However, the rapid and repeated
use of this material during the winter soon disclosed the fact, the
truth of which has always been held by the speaker, that it would be
necessary to plaster the building, if it was to be given a character on
a par with the average office structure.
No plans of the forms are included in the paper, although reference
to them appears at one point.
In the speaker's opinion, the tower used in the erection of this
building was really a factor of large economy. For instance, all con-
crete was hoisted to each floor in buckets dropped through the elevator
shafts to the mixers, which were in the basement and placed so as to
dump directly into the buckets as they rested. The booms swung the
buckets so that they could be dumped exactly at the desired points,
thus obviating the use of other hoists, hoppers, wheel-barrows, runways,
etc. This method proved so effective that very often the cost of all
labor on concrete for considerable quantities would not exceed 40 cents
per cu. yd.
The speaker certainly would repeat the use of that special con-
trivance on a similar operation, except that he would stiffen the struc-
ture to a somewhat greater extent, and would use 12 by 12-in. timbers
for corner posts instead of the 10 by 10-in. posts used in this instance.
The tower structure also served as a storage space, and was of almost
inestimable value in this respect, because of the congested portion of
the city in which the building stands.
During cold weather, besides making use of the salamanders,
as described by the author, the concrete was mixed with hot water and
all aggregates were heated so as to prevent frozen lumps from getting
into the work. On one operation with which the speaker was con-
nected he once removed a lump of frozen sand from a column in
which it would have occupied about 15% of the total area. The
necessity of heating the aggregate is obvious, since, even when boiling
water is thrown into the mixer, it has such speed of operation that not
enough time elapses to thaw frozen masses and get them properly
distributed, before the mixing process is complete.
With the methods used on the McGraw Building, even in the
coldest weather, the concrete would reach the point of deposit at a
temperature ranging from 50 to 75° fahr., and would have attained
its initial set while its temperature was still warm to the touch. The
Papers.] DISCUSSION ON REINFORCED CONCRETE BUILDING 61
salamanders maintained a temperature in the dead air spaces between Mr. Goodrich,
the beams, which often reached 100° fahr., and seldom fell below
60°, even in zero weather.
Of course, the special interest of this paper centers around the type
of column. The speaker feels that, even at the present time, the de-
signing of reinforced concrete columns is like working in a darkened
room, and this is said even after personally making a large number of
column tests, and after carefully analyzing nearly a hundred others.
If carefully designed, and when a proper relation exists between the
longitudinal and spiral steel, the speaker considers a Considere column
entirely practicable for a reasonably high building with comparatively
light floor loads; but, for more lofty structures, the opinion is gain-
ing strength, in the speaker's mind, that a regular structural steel
column should be used, in connection with reinforced concrete girders,
beams, and floors, if desired. This structural column, however, should
be of some open design, and it should be completely filled with con-
crete and surrounded by a fire-proofing at least 3 in. thick over all
extreme edges. Such a composite building will be more economical
than any other, in yearly carrying charges, including interest on first
cost, insurance, maintenance, heat, etc., and a correspondingly larger
income can be derived therefrom.
62 MEMOIR OF NATHANIEL HENRY HUTTON [Memoirs.
MEMOTES OF DECEASED MEMBERS.
Note.— Memoirs will be reproducpcl in the volumes of Transactions. Any information
which will amplify the records as here printed, or correct any errors, should be forwai'ded
to the Secretary prior to the final publication.
NATHANIEL HENRY HUTTON,* M. Am. Soc. C. E.
Died May 8th, 1907.
Nathaniel Henry Hutton was born on November 16tli, 1833, in
Washington, D. C, and died in Baltimore, Maryland, on May 8th,
1907. His earliest ancestor in the United States of whom there is any
record, John Strangeways Hutton, was born in New York City in 1684
iind died in Philadelphia in 1792. His father was James Hutton, who
married Salome Rich of Boston, Mass., in Washington, D. C.
Following the example of his elder brother, the late William Rich
Hutton, M. Am. Soc. C. E., "Harry" (as he was familiarly called by
those who knew him well) entered the service of the United States at
;ui early age, adopting the profession of civil engineering. Neither had
the advantage of a collegiate education, but they did have the good
fortune to grow up under the thorough training of those days, in the
specially excellent schools of Alexandria and Washington, taught by
men like Ben Hallowell, Abbot and others. They made good use of
those early opportunities, and by industry, faithful attention to duty,
and continual study of the theory of engineering and the works of able
engineers, their own experience and unusual natural talents enabled
them to pass through the lower grades of the profession with credit to
themselves, and with the respect and ever-increasing confidence of their
superiors in their integrity and high tone, until they had come to rank
well among the engineers of their period in the special lines to which
their attention was called.
Mr. Button's work as a surveyor and engineer, up to 1896, may be
summarized briefly as follows:
He was U. S. Assistant Engineer on explorations and surveys for
the Pacific Railroad west of the Missouri River, on the 32d and 35th
Parallels, from 1853 to 1856, inclusive; Chief Engineer of the El Paso
and Fort Yuma wagon road (Department of Interior) during 1857 and
1858; Surveyor on the western boundary of Minnesota (Department of
Interior) during 1859 and 1860; U. S. Assistant Engineer on the de-
fenses of Baltimore from 1861 to 1865 ; U. S. Assistant Engineer in
charge of the improvement of the Patapsco River from 1867 to 1876,
nnd on the Western division of the Virginia Central Water Line (sur-
vey 1874 to 1875) ; and from 1876 until his death he was Engineer to the
Harbor Board of Baltimore; he was also U. S. Assistant Engineer in
charge of surveys for a ship canal to connect the Chesapeake and Dela-
* Memoir prepared by William P. Craighill, Past -President, Am. Soc. C. K.
Memoirs.] MEMOIR OF NATHANIEL HENRY HUTTON 63
ware Bays during 1878 and 1879; Consulting Engineer for a project for
a ship canal between Philadelphia and the Atlantic Ocean in 1894 and
1895; and Consulting Engineer for a projected ship canal to connect
Lake Erie and the Ohio Eiver in 1895 and 1896.
For many years previous to 1896, and up to the time of his death,
Mr. Hutton had been Chief Engineer to the Harbor Board of the City
of Baltimore. That he held this office so many years, during the admin-
istrations of mayors and councils of opposing political parties, is proof
that his services were considered so valuable as to be almost indispen-
sable. Later, he became President of the Harbor Board, as well as
Chief Engineer.
The following tribute from the Harbor Board shows the high esteem
in which he was held by his associates, and it may be said with truth
that this was the sentiment of the business men of Baltimore who were
best acquainted with his work and ability:
"The death of Major Nathaniel H. Hutton, Engineer of the Harbor
Board of Baltimore City, comes at a time and under conditions which
cause especially deep feelings of sorrow and regret in the minds of the
members of the Harbor Board.
"Immediately after the fire of February 7th and 8th, 1904, he was
called upon by the citizens of Baltimore to suggest and design plans for
the new docks and the improvements of the harbor of this City. The
preparations of these plans, together with his other duties as engineer
of the Harbor Board, devolved upon him a very great amount of skill-
ful professional work, and it is probable that he unconsciously over-
taxed his strength in this way.
"The influence which Major Hutton has exerted upon the plans for
the improvement of the Harbor, cannot be estimated. He has not lived
to see the realization of what he has planned, bvit there can be no doubt
that his activity and experience in this great work will be appreciated
by his successors, and the citizens of Baltimore, when the full effects
of his labors and efforts are realized.
"Major Hutton was an engineer of rare ability and of vast and
varied experience. He was a gentleman of the old school, and a most
faithful engineer and honest public servant.
''Resolved, that in the death of Major Nathaniel H. Hutton, the
City of Baltimore has been deprived of a noble and trusted citizen and
a capable and conscientious public servant, who has devoted many years
of his life to her interests.
"Resolved, that the members of the Harbor Board, who particularly
appreciate the full measure of loss suffered by his death, tender their
sympathies to the family of the deceased, and that these Resolutions be
spread upon the Minutes of the Board."
There are also appended resolutions adopted May 19th, 1907, by the
Board of Public Improvements, of which Mr. Hutton was a prominent
member :
"At a special meeting of the Board of Public Improvements held
this date called to take action on the death of Major N. H. Hutton,
64 MEMOIR OF NATHANIEL HENRY HUTTON [Memoirs.
President and Chief Engineer of the Harbor Board, the following reso-
lutions were adopted :
"Resolved, that by the death of Major Button the City of Baltimore
has lost a most faithful and efficient public officer, whose long service
as Harbor Engineer here and extended experience on important public
works elsewhere made his services invaluable to this city.
"Also by his death, we, his fellow members of the Board of Public
Improvements, have lost a trusted friend and wise counsellor, whose
uniformly genial and courteous nature greatly endeared him to us.
"We extend to his family our sincere and heartfelt sympathy in
their great sorrow."
Mr. Hutton was a Charter Member and Vice-President of the Engi-
neers' Club of Baltimore. At his death the Club took the following
action in his honor:
'^Whereas, We, the members of the Engineers' Club of Baltimore,
have learned with sincere sorrow of the death of our fellow member.
Major N. H. Hutton; and whereas we recognize his earnest efforts, as
a Charter Member and Vice-President, to promote the welfare of the
Club, and the active, friendly and generous interest, manifested by
him, in establishing its success :
"Resolved, that in his death the Engineers Club of Baltimore has
been deprived of a distinguished member and a Loyal and Honoured
Friend."
Mr. Hutton was also an architect of decided ability, as is shown by
the outcome of the designs proposed by the firm of Hutton and Mur-
dock, of which he was a member for several years, for the construction
and alteration of a number of churches, dwelling-houses and warehouses
in Baltimore, Washington, Virginia and Pennsylvania. One of his
designs for a highway bridge in Baltimore was considered by a very
judicious board to be the best among five that were submitted. Not
only was Mr. Hutton esteemed as an able engineer and architect and a
capable and faithful official, but he was admired and loved by his
friends in an unusual degree. A few extracts are appended from many
testimonials that have been received as proof of the statements already
made.
After a long intercourse, under conditions which often test men's
character, long-drawn-out surveys among the rough surroundings of
camp life, in the midst of Indians and uncultivated and often lawless
frontier people, both male and female, one of his closest friends writes :
" 'Tis said that you must sleep with a man to learn his peculiarities.
Well, if this is true, Harry and I ought to have become pretty well
acquainted, for the nights we stretched ourselves on the ground under
the same blanket, ate oiir grub out of the same tin pan, and drank our
coffee out of the same tin cup, ran through years, and during the entire
time our affection became closer. It was only necessary to know him to
love him, and, of the many acquaintances I have made during a long
and varied life, I have yet to meet the man who excelled him in the
Memoirs,] MEMOIR OF NATHANIEL HENRY HUTTON 66
noble qualities of head and heart which he possessed. He was one of
Nature's noblemen, a conscientious Christian whose only fear, if he
knew what fear was, was to do wrong, and whose sense of honor was as
firmly fixed as the everlasting hills."
Another, with whom Mr. Hutton had close professional and personal
contact in Baltimore, gives the following high testimonial from himself
and others of their mutual associate:
"All of us had the highest appreciation of his ability as an engineer
and of the value of his services to the city. He had been our Harbor
Engineer for so many years that he had become indispensable in the
working of our city government. His advice was frequently sought by
municipal engineers and other municipal officials, and his opinion was
always respected on all engineering questions. He was progressive,
broad and liberal in his views, yet conservative enough to hold down
some of us younger and rasher engineers. He was a conciliating and
harmonizing influence at all gatherings of engineers and meetings of
boards and commissions. His personality was such, and his manner
was so genial and kindly, that he could regulate or harmonize where
others could not, and yet always retain the regard and affection of his
associates.
"Because of his years of experience and of his broad learning, his
place in our municipal government will be hard to fill. His place in
our affections can never be filled."
Another who had served with Mr. Hutton very closely for many
years adds:
"As an engineer, he was capable, careful, eminent and prominent,
and was consulted in the development of many projects of National
importance. On undertaking any new work he sought the results and
opiniond of others of distinction and after giving careful consideration
formulated his plans.
"As a public official, he was earnest, honest and faithful, possessing
a keen power of penetration, and his approval always carried weight.
"As a man, he was modest and retiring, affable and lovable, with
ever a kind word for his fellow-man, be he high or low, and all in all
a splendid type of a gentleman."
Still another says:
"I was thrown in intimate relations with him. He was always to me
the embodiment of a true gentleman, in the highest and best sense of
that word; honorable and truthful, above suspicion, always courteous
and always manly.
"As an engineer, he was well trained and on broad lines. I had
great confidence in him, and frequently consulted him about difficult
problems coming up in my work, and always got sound and helpful
advice. If I were called upon to name some special characteristic of
Major Hutton, which distinguished him as an engineer, I should say
that good judgment was his strong point.
"His death leaves a great blank, both professionally and socially.
My feelings for Major Hutton were those of real, genuine affection.
66 MEMOIR OF NATHANIEL HENRY HUTTON [Memoirs.
and I believe that most men who came in close contact with him had
the same. It is difficult to imagine a true man having any sentiments
for Major Hutton other than those of the profoundest confidence and
respect."
The writer knew Mr. Hutton for more than forty years, both profes-
sionally and socially, and can fully bear testimony to the fact that what
is said by others in what precedes is not exaggerated. His domestic
life was charming and lovely.
In early manhood, Mr. Hutton married Miss Meta Van Ness,
daughter of Colonel Eugene Van Ness of the United States Army,
who was a member of the well-known and distinguished family of that
name in the State of New York. One of Mrs. Hutton's ancestors was
Admiral Van Ness of Holland, who lived in 1653 ; and in Scotland her
lineage dates distinctly and honorably at least to 1542.
Mr. Hutton passed from time to eternity in May, 1907, and his
devoted wife followed in September. They left three children, all resi-
dent in Baltimore, Mr. Harry Hutton, Mrs. S. S. Busby and Mrs. C.
H. Wyatt.
Mr. Hutton was elected a Member of the American Society of Civil
Engineers on June 3d, 1896.
AMERICAN SOCIETY
OF
CIVIL ENGINEERS
February, 1908.
PROCEEDINGS = VOL. XXXIV— No. 2
AMERICAN
SOCIETY OF
CIVIL
^ENGlNEEpSi
By
W.LUAM P. Morse
Published at the House of the Society, 220 West Fifty-seventh Street, New York
the Fourth Wednesday of each Month, Except June and July.
Copyrighted 1908, by the American Society of Civil Engineers.
Entered as Second-Class Matter at the New York City Post Office, December 15th, 1896.
Subscription, $6 per annuna.
Vol. XXXIV. FEBRUARY, 1908. No. 2.
AMEKIOAN SOCIETY OF CIVIL ENGINEERS.
INSTITUTED 185 3.
PAPERS AND DISCUSSIONS.
This Society is not responsible, as a body, for the facts and opinions advanced
in any of its publications.
CONTENTS.
Papers : page.
The Electrification of the Suburban Zone of the New York Central and Hudson
River Railroad in tne Vicinity of New York City.
By William J. WiLGUs, BI. Am. Soc. C. E 68
The Flood of March. 1907, in the Sacramento and San Joaquin River Basins,
California.
By W. B Clapp, M. Am. Soc. C. E., E. C. Murphy, Assoc. M. Am. Soc. C. E.,
AND W. F. Martin, Jun. Am. Soc. C. E 99
Discussions :
The Reinforced Concrete Work of the McGraw Building.
By Messrs. T. L. Condron and F. F. Sinks, E. AV. Stern, L. J. Mensch. and
P, E. Stevens 149
The Use of Reinforced Concrete in Engineering Structures : An Informal Discus-
sion.
By Messrs. E. P. Goodrich, Edwin Thacher. Sanford E. Thompson, W. H.
Burr, T. Kennard Thomson, D. W. Krellwitz, Guy B. Waite, and C. L.
Slocum 169
Memoir :
Charles Paine, Past-President, Am. Soc. C. E 196
PLATES.
Plate V. Map of the Electric Zone, New York Central and Hudson River Rail-
road, in the Vicinity of New York City 69
Plate VI. Port Morris and Yonkers Power Stations, Cable Tower, Etc 71
Plate VII. Cross-Section and Plan of Port Morris Power Station 73
Plate VIII. Aerial and Duct Tran^ mission Lines. 75
Plate IX. Splicing (Jhambsr, Submarine Crossing, and Sub-Station 75
Plate X. Third-rail, Circuit- Breaker House, Operation of Third-rail in Winier,
and Electric Locomotive 75
Plate XI. Electri3 Trains, " Jump?r," and Reactance Bond 78
Plate XII. Electric Locomotive, and Bi- polar Gearless :Vlotor 79
Plate XIII. Train Braking Charts for Distance and Speed 81
Plate XIV. Terminals at North White Plains, Hi^h Bridge, and Wakefield , . 83
Plate XV. Harmon Shops, and Grand Central Yard 85
Plate XVI. Present Grand Cential Station and Train-shed, and Excavation in
Progress at <Grand Central Terminal 87
Plate XVII. Contrast Between Smoke Conditions at Grand Central Terminal, Be-
fore and After Electrifleation 89
Plate XVIII. Proposed Bronx Station and Improvement, and Typical Grade Cross-
ing Elimination 91
Plate XIX. Grade Crossing Elimination, Marble Hill Cut-off, Signal Tower, etc. ... 93
Plate XX. Four and Six-tracking, Typical Signals, and Typical Fencing 93
Plate XXI. Table 3: Comparative Tests of Steam and Electric Locomotives 95
Plate XXII. Profile from Grand Central Station to White Plains 97
Plate XXIII. Map of I>rainage Basins of Sacramento and San Joaquin Rivers,
California 105
Plate XXIV. Reinforcement and Concreting. Watson Building 151
PlateXXV. Maniitacturets' Furniture F-xehange Building 153
Plate XXVI. Reinforcement and Concreting, Manufacturers' Furniture Exchange
Building 1 55
Plate XXVII. Exterior and Interior, Manufacturers' Furniture Exchange Building. . 157
Vol. XXXIV. FEBRUARY, 1908. No. 2.
AMEEICAN SOCIETY OF CIVIL ENGINEERS.
INSTITUTED 1852.
PAPERS AND DISCUSSIONS.
This Society is not responsible, as a body, for the facts and opinions advanced
in any of its publications.
THE ELECTRIFICATION OF THE SUBURBAN ZONE
OF THE
NEW YORK CENTRAL AND HUDSON RIVER RAIL-
ROAD IN THE VICINITY OF NEW tORK CITY.
By William J. Wilgus, M. Am. Soc. C. E.
To BE Presented March 18th, 1908.
The recent successful completion of the electrification of the service
of the New York Central and Hudson River Railroad entering the
Grand Central Terminal, New York City, marks such an important step
in the progress of the art of transportation that a paper seems at this
time appropriate, explaining the reasons for the abandonment of steam,
the general features of construction and operation, and the results.
Two decades have passed since electricity in the United States first
commenced its important career in the field of lighter traffic; but only
within the past few months has it fairly met its steam rival in heavy-
traction trunk-line service.
Reasons for Delay in Electrification of Trunh Lines. — The reason
for this delay is not far to seek. The steam locomotive, during its
lifetime of eighty years, has been developed into a wonderfully reli-
able, efficient, and powerful machine, deep-seated in thp affections of
Note. — These papers are issued before the date set for presentation and discussion.
Correspondence is Invited from those who cannot be present at the meeting, and may bo
sent by mail to the Secretary. Discussion, either oral or written, will be published
in a subsequent number of Prorerdinas. and, when finally closed, the papers, with
discussion in full, will be published In Transactions,
PLATE V.
PAPERS AM. 80C. C. E.
FEBRUARY, 1908.
WILQUS ON
ELECTRIFICATION OF SUBURBAN ZONE
OF N. Y. C. 4 H. R. R. R.
Papers.] ELECTKII'ICATION, SUBUltBAN ZONE, N. Y. C. & 11. K. R. R. G9
the railroad world. With the conservatism naturally born of these
conditions is the reluctance of stockholders to spend vast sums for
changes of unproven financial value.
There is no cause for surprise, therefore, that electricity, so com-
monly associated in the mind of the railroad officer with light street-
car traffic, has not been seriously considered as a substitute for steam,
until special problems have arisen demanding some escape from the
limitations and nuisances incident to the use of steam locomotives.
The very fact that steam locomotives have grown so in size and
power makes them more objectionable as emitters of increased volumes
of noise, smoke, gas, and cinders.
The first important instance of the use of electricity on a large
scale was in utilizing electric locomotives to push solid trains, with
their inactive steam locomotives, through the Baltimore Tunnel of the
Baltimore and Ohio Railroad. In this instance, electricity was adopted
as an aid, not as a substitute for steam.
Reasons for Electrification of New York Central. — As early as 1899,
thought was given to the use, on the New York Central, of electricity
for curing the evils at the entrance to the Grand Central Terminal;
but it was not until 1903 that the objectionable atmospheric conditions
in the Park Avenue Tunnel, and the congestion of traffic at the termi-
nal, precipitated legislative action directing the complete abandonment
of the steam locomotive in Park Avenue south of the Harlem River,
within a period of five years terminating July 1st, 1908.
In the same year the railroad company and the city agreed upon
radical changes at the terminal, which were possible only with the
abandonment of steam. From a civic standpoint, the most important
of these changes is the depression of the whole terminal, so as to
permit the extension of highways over the tracks from Forty-fifth to
Fifty-sixth Streets, inclusive, and the continuation of Park Avenue, 140
ft. wide, within the same limits, thus joining two sections of the city
hitherto separated for | mile by an impassable barrier of railroad yards
and structures.
Reasons for Extended Scope of Electrification. — A careful analysis
of the situation soon proved the absurdity of terminating the electric
zone at or near the Harlem River.
Immediately north of that point is Mott Haven Junction, where
the line splits, one leg known as the Harlem Division continuing north
70 ELECTRIFICATION, SUBUEBAN ZONE, N. Y. C. & H. R. R. R. [Papers.
to Chatham on the Boston and Albany Railroad, and the other consti-
tuting the main line of the Hudson Division, bearing to the west and
north, along the banks of the Hudson River, to Albany and beyond.
At Woodlawn Junction, on the Harlem Division, is the point of conflu-
ence with the New York, New Haven and Hartford Railroad, the very
large passenger traffic of which flows over the rails of the New York
Central to and from the Grand Central Terminal, a distance of 12 miles,
From the Grand Central Terminal to Woodlawn Junction, the
Harlem Division is four-tracked, but for the remainder of the distance
within the territory under discussion, but two tracks existed for hand-
ling all classes of traffic. Similarly, on the main line, from the junction
at Mott Haven, two tracks w'ere called upon to transport both passenger
and freight trains, except on the section between Spuyten Duyvil and
Scarborough, where a third track aided to some extent.
In addition to the extremely heavy through passenger train service
from the New England, northern and western States of the Union,
and Canada, there is an important local traffic extending as far out as
Harmon, on the Hudson Division, a distane of 33 miles. North White
Plains, on the Harlem Division, a distance of 24 miles, and Stamford,
on the New York, New Haven and Hartford Railroad, a distance of 34
miles, from the Grand Central Station.
A further burden on the four-track stem between the terminal and
Mott Haven Junction is the hauling between those points of "dead"
equipment, because of inadequate storage space at the station.
From this recital it will be seen that a termination of the electric
zone at the Harlem River, or at Mott Haven Junction just above the
river, would entail the stoppage a;id change of motive power from
steam to electricity and vice versa, of all kinds of traffic, at a point
peculiarly subject to congestion. Moreover, the physical conditions in
the neighborhood precluded the construction of the necessary facilities
for the storage and care of motive power.
Because of these fundamental objections, and, moreover, guided by
the broad-minded policy that growth of traffic responds to the use of
electricity, the company decided to extend the limits of the electric
zone to the northerly termini of the suburban territory, at Harmon
and North White Plains, where ample space is available for loops,
yard tracks, and buildings. The geography of the territory is shown
on Plate V.
PLATE VI.
PAPERS, AM. SOC. C. E.
FEBRUARv, 1908.
WILQUS ON
ELECTRIFICATION OF SUBURBAN ZONE
OF N. Y. C. & H. R. R. R.
Papers.] ELECTKIiaCATION, SUHUJtBA]^ ZONK, N. Y. C. & H. R. R. R. 71
Reasons for Other Improvements. — This decision, and the demands
of growing traffic for more and better facilities, led to the adoption of
plans for a new Grand Central Station with two track levels; the
separation of track grades and a new overhead eight-track station at
Mott Haven; the elimination of all grade, street, and highway crossings;
the "four-tracking" of both divisions as far as the termini; many new
and enlarged passenger and freight stations; new electric automatic
signals, and electric interlocking plants ; and many important revisions
of alignment and grades.
Reasons for Adopting the Direct-Current System. — About this time
the battle had just opened in the United States between the two rival
systems of electricity — direct and alternating current. Of coiirse, the
advocates of each argued that the pther was unsuited to New York
Central conditions, and it was "only after lengthy and thorough consid-
eration that the direct-current system was selected.
The principal reasons for this conclusion, apart from technical
points, may be summarized as insufficient practical development of the
alternating-current system for a trunk-line problem reqiiiring absolute
reliability of service, restricted clearances which forbade the use of
overhead conductors, and legal obstacles to the use of overhead trolley
wires carrying high voltages within the limits of the City of New York.
Reasons for Not Using Alternating-Current Equipment on a Direct-
Current System. — Some time after this decision had been made, and
apparatus had been ordered, the company was urged by outside inter-
ests to abandon the tyi^e of equipment suited exclusively to the direct-
current system, and adopt another type which could operate on both
direct and alternating currents. It was claimed that, by making this
change, the equipment would be available for use on later extensions
of the electric zone where there were no physical or legal objections
to the use of alternating current. The wisdom of adhering to the type
of equipment already chosen has been proven by recent comparative
tests of locomotives of the two types under exactly the same conditions,
which demonstrate that the one designed only for direct current con-
sumes from 15 to 25% less current than the one intended for use on
both systems. This will effect a saving to the company of at least
$140 000 per annum. If to this item is added the economy resulting
from less locomotive ton-miles per annum because of the lower weights
of locomotive per unit of capacity, and lower wages, fixed charges, and
72 ELECTRIFICATION, SUBURBAN ZONE, N. Y. C. & H. R. R. R. [Papers.
maintenance of equipment, because of the smaller number needed to
do the same work, the total saving for the ultimate electric zone, result-
ing from adherence to the adopted type of direct-current locomotive,
will be approximately $300 000 per annum.
Reasons for Duplicate Power Stations and Transmission Lines. —
One of the strongest arguments advanced against the substitution of
electricity for the well-tried steam locomotive, for the movement of
the most important passenger, mail, and express service in the country,
is the vulnerability of power stations and distributing systems to failures
of the class which affect, not one, but all, units. To overcome this well-
founded criticism, two cross-connected power stations were decided
upon, accessible to both rail and boat coal; and each with sufficient
capacity, utilizing its spare unit, and working "overload," to carry the
entire demand of the service at the rush hours shovild the other fail.
It was considered that the growing familiarity of the operating force
with the new conditions, and the elimination, in time, of unsuspected
defects of installation, would later make the surplus capacity available
for other uses, such as increased demands of traffic, the movement of
freight trains by electricity, and the operation of the terminals of the
company on the west side of Manhattan Island. As a further precau-
tion, duplicate transmission lines were adopted in the more important
portions of the territory, so that the failure of one would still leave
the other effective for the uninterrupted movement of trains.
Reasons for Storage Batteries. — Even with these two safeguards,
there appeared to be vulnerable places, where accidents might put
essential features of the service out of commission, and to overcome
this, as well as to make suitable regulation of violent fluctuations of
load on the power stations and sub-stations, storage batteries were
adopted with capacity sufficient to tide over the usual maximum periods
of interruption of current supply, that experience elsewhere has shown
may be expected.
Reasons for Combined Locomotive and Multiple-V nit Practice. —
While, necessarily, through trains with cars originating at far distant
points must be hauled by electric locomotives within the electrified
territory, it was evident from the start that, for the company to reap
the full advantage from its expenditures, the multiple-unit type of
suburban equipment should be adopted that elsewhere had been shown
was essential for the propagation of traffic, and the simplification of
PLATE VII.
PAPERS, AM. SOC. C. E.
FEBRUARY, 1908.
WILQUS ON
ELECTRIFICATION OF SUBURBAN ZONE
OF N. Y. 0. & H. R. R. R.
^-m,.^
^_ fj^.-l: -a. It IF f-
Fig. 1.— Typical Cross-Section of the Port Morris Power Station.
Fig. 2.— Typical Plan of Port Morris Power Station.
Papers.] ELECTEIFICATION, SUBURBAN ZONE, N. Y. C. & H. R. R. R. 73
operation in congested terminals. By dispensing with locomotives in
suburban service, and equipping the individual cars with electric
motors controlled from either end of the train, it becomes possible to
meet the demand of the public for less interval between trains, and at
the same time regulate the cost of operation to the volume of traffic at
various periods of the day. The absence of locomotives, and the distri-
bution of power among the cars practically eliminates switching, and
movements to and from engine-houses, with a resultant great reduction
of the causes that congest terminals. A twofold character of equip-
ment, therefore, was adopted — locomotives for through trains, and mul-
tiple-unit cars for the passenger service confined to the electric zone.
Awarding First Contracts. — With all the foregoing questions settled,
plans and specifications were actively prepared, and contracts awarded
in the fall of 1903 for the apparatus requiring the longest time for
delivery, including power-station machinery and locomotives. Later,
arrangements were made for the remaining items of the installation,
either by contract or by company forces.
General Features of Construction.
Principal Elements of the Installation. — The principal elements of
the installation are the duplicate power stations for generating 3-phase,
11 000-volt, 25-cycle alternating current ; the high-tension transmission
lines for distributing this current to the sub-stations; the sub-stations
for transforming and converting the high-tension alternating current
to 660-volt direct current, and for the storage of current in batteries;
the direct-current transmission lines for the distribution of energy
to the working conductors; the third-rail and overhead conductors at
special places, known as working conductors, for the delivery of the
660-volt current to the contact shoes on locomotives and cars; the
electrical equipment ; repair shops and inspection facilities ; interchange
terminals for electric and steam power; and last, but not least, the
building up of an operating organization to make all this intricate
machinery a working success.
Power Stations. — Each power station is equipped initially with six-
teen water-tube, 625-h.p. boilers, with superheaters and mechanical
stokers, and four 5 000-k.w. Curtis turbo-generators, together with the
necessary condensers, pumps, exciters, feed-water heaters, and appur-
tenances. Additional space is provided in the buildings, for a later
74 ELECTRIFICATION, SUBURBAN ZONE, N. T. C. & H. R. R. R. [Papers.
expansion of capacity to the extent of 50% of the initial installation.
It will thus be seen that each station has a present normal capacity of
approximately 28 000 h.p. (20 000 k.w.), with provision for an ultimate
increase to approximately 42 000 h.p. (30 000 k.w.), or a combined
ultimate normal capacity of approximately 84 000 h.p. (60 000 k.w.).
The two stations are electrically cross-connected, so that, for all prac-
tical purposes, they act as one.
Both. power stations are supplied with mechanical plants for trans-
ferring coal from car or boat to overhead bins, each station having a
storage capacity of 3 500 tons, equal to 9 days' supply under maximum
conditions.
A pilot switch-board is located in the gallery of each power station,
but the important control apparatus, including oil switches, is placed
in a separate building, so that serious trouble in the main structure
will not disable or injure what may be termed the brains of the system.
The buildings are constructed substantially, of concrete, brick and
steel, on stable foundations, and with an architectural treatment suited
to the purposes for which they are designed. The twin stacks at each
station are of perforated radial brick, have an average internal diam-
eter of 16 ft. 3 in., and rise to a height of 267 ft. above the ground.
A noteworthy fact may be recorded that illustrates one of the
advantages of turbo-generators in the economical design of power-
station buildings. The capacity required at the Yonkers station is
only 110 cu. ft., and that at the Port Morris station 115 cu. ft. per
k.w., as compared with from 170 to 255 cu. ft. at the more important
reciprocating-engine plants in New York City.
The maximum calculated 4-min. peak load on both stations is
24 000 k.w., at which time 38 trains, of varying speeds, weighing in all
9 800 tons, are assumed to be in motion. The annual output is expected
to aggregate 121000 000 kw-hr., of which 107 000 000 kw-hr. are for
the propulsion load and the remainder for lighting and other purposes.
These figures do not include the fviture additional requirements for
switching at various yards, the movement of freight trains, and the
operation of labor-saving devices at terminals.
11 000-Volt Transmission Line. — The 11 000-volt alternating current
from the power stations is led to the sub-stations by duplicate systems
of insulated copper cables in ducts within the populous districts of the
city; and by bare copper cables suspended on substantial steel poles set
PLATE VIM.
PAPERS, AM. SOC. C. E.
FEBRUARY, 1908.
WILQUS ON
ELECTRIFICATION OF SUBURBAN ZONE
OF N. Y. C. & H. R. R. R.
PLATE IX.
PAPERS, AM. SOC. C. E.
FEBRUARY, 1908.
WILGUS ON
ELECTRIFICATION OF SUBURBAN ZONE
OF N. Y. C. &. H. R. R. R.
PLATE X.
PAPERS, AM. SOC. C. E.
FEBRUARY, 1908.
WILGUS ON
ELECTRIFICATION OF SUBURBAN ZONE
OF N. Y. C. & H. R. R. R.
Papers.] eLECTKIFICATION, SUBUKBAN ZONE, N. Y. C. & H. E. R. R. 75
in concrete bases in the less densely settled districts. This arrange-
ment was adopted only after an exhaustive investigation of line con-
struction throughout the country had proven the greater safety and
reliability of well-built aerial wires, where the population is sparse and
the line is located on private right of way.
Where the cables pass from one type of construction to the other,
they are led through brick towers equipped with lightning arresters.
Owing to the failure of the city to grant the right to place the
cables beneath the surface of neighboring streets, it was necessary to
locate them within the right-of-way limits of the company, and this
required many varied types of construction, often taxing the ingenuity
of the engineers to place the conduit pipes where they would be safe
from injury. A few of these conditions are illustrated in the accom-
panying photographs. Altogether, there will be 16 miles of conduit
territory, and 46 miles of pole lines, together with 383 splicing
chambers.
Substations. — There are to be eight sub-stations, four of which
are now in operation. Their total normal rotary capacity will be
27 000 k.w.
Each station contains transformers for reducing the voltage from
11 000 volts primary to 450 volts secondary, and rotary converters for
changing the current from alternating to direct at 660 volts. Storage
batteries, "floating on the line," are also provided, to regulate the sharp
fluctuations of the peculiarly severe short-period demands incident to
heavy traction service, and to safeguard the continuity of traffic should
perchance the supply of current be interrupted by power station or
distributing failures. This insurance of reliability of service has
already demonstrated the wisdom of its adoption. The aggregate
momentary capacity of the batteries will be 37 786 k.w., with an hourly
capacity of 12 595 k.w.
660-Volt Feeder System. — The 660-volt direct-current system, for
conveying energy to the working conductors, consists of copper cables
protected and arranged similarly to the high-tension lines already
described.
Working Conductors. — The working conductors deliver 660-volt cur-
rent to locomotives and cars. Third-rail is used at all points, except
where intricate switch lay-outs prohibit a continuous conductor near
the level of the track. At such places overhead conductors are used.
76
ELECTRIFICATTONT, SVEUEBAN ZONE, N. Y. C. & H. R. R. R. [Papers.
PLATE XI.
PAPERS, AM. SOC. C. E.
FEBRUARY, 1908.
WILQUS ON
ELECTRIFICATION OF SUBURBAN ZONE
OF N. Y. C. & H. R. R. R.
Papers.] ELECTRIFICATION, SUBURBAN ZONE, N. Y. C. & H. R. R. R. 77
either of a temporary character where future track changes are con-
templated, or permanently suspended from overhead bridges and build-
ings. The adopted type of third-rail is unique, for the reason that the
current is collected from beneath instead of from the top. This permits
the sides and upper parts of the rail to be sheathed in wood or other
insulating material in a way that safeguards employees and others from
accidental contact, and protects the contact surface from sleet and
snow which, with the usual types of top-contact rail, so frequently
cause tie-ups of traffic. The manner of construction is such as to
secure all these advantages, without encroachment within the clearance
lines of the steam equipment, and without precluding the interchange
of electric equipment with other lines already using the top-contact
type.
At frequent intervals, the direct-current cables pass through small
circuit-breaker houses, in which circuit-breakers automatically open
and interrupt the flow of current, when, because of accident or injury,
there is an improper leak in the third-rail system or the direct-current
feeder system. This safety device, therefore, automatically checks the
delivery of current to the working conductors, when a continuation
of the supply might be disastrous. The circuit-breakers are controlled
by cables connected with neighboring sub-stations. Numerous other
precautionary measures have been taken for shutting off power promptly
in case of accident, such as, for instance, continuous indicator wires
for each of the four tracks in the Park Avenue Tunnel, that enable
the power to be shut off immediately on any desired track.
In all, there will be 52 miles of territory, embracing 285 miles of
track equipped with third-rail, of which more than one-third is com-
pleted and in use.
Track Bonds. — The bonding of the track rails for the return cur-
rent was a task of considerable proportions, because of the intimate
relation of the work to traffic. Several ingenious devices were used in
expediting the drilling of rails and placing the bonds. The concealed
type of bond was used as a protection against the thefts that embarrass
traffic and entail pecuniary loss, and to obviate injury by trackmen.
Electrical Equipment. — The electrical equipment now in use com-
prises 35 locomotives and 180 suburban cars. Of the cars, 125 are
equipped with motors. The remainder, for the present, act as trailers,
although motors will be added when the electrical service is extended
78 ELECTRIFICATION, SUBURBAN ZONE, N. Y. C. & H. R. R. R. [Papers.
SPEED AND ACCELERATION CURVES
ELECTRIC LOCOMOTIVES.
2.0
100
300 300 400 500
Total Weight of Cars, in Tons.
Fig. i.
GOO
PLATE XII.
PAPERS, AM. SOC. C. E.
FEBRUARY, 1908.
WILQUS ON
ELECTRIFICATION OF SUBURBAN ZONE
OF N. Y. C. & H. R. R. R.
Fig. 1.— Electric Locomotive.
Fig. 3.— Bi-polar Gearless Motor.
Papers.] ELECTRIFICATIOISr, SUBURBAN ZONE, N. Y. C. & H. R. R. R. 79
the full distance to Harmon and North White Plains. The aggregate
normal rating of both classes of equipment is 127 000 h.p.
Locomotives. — The locomotive is a peculiarly efficient and powerful
machine. Although weighing 94.5 tons, complete, as compared with
the 171-ton weight of the heaviest 'teteam passenger locomotives in use
by the company, its normal rating of 2 200 h.p. is practically twice that
of its rival; it has 76^ tons less weight to haiil about, thus effecting a
saving of 45% for energy in moving dead tonnage; its concentrated
weight per driving axle, 34 250 lb., is 27% less than that of the steam
locomotive, without decreasing the total driver weight available for
traction; it is capable of running at will in either direction, without
the delays and expense of going to the turn-table; it occupies little
more than half the track space of the steam locomotive — an important
advantage in terminals — and it is much more quickly started and
stopped. These advantages have been demonstrated strikingly in prac-
tice, both in comparative trials on the 6-mile experimental track near
Schenectady, where all the new equipment was tested exhaustively
before acceptance, and in regular service in the New York zone.
The principal characteristics of the locomotive are :
Length over all 37 ft. 0 in.
Rigid wheel base
Total wheel base
Diameter of drivers
Diameter of truck wheels ^
Total weight
Weight on four drivers
Weight on two trucks
Horse-power per ton of weight — normal capacity ....
Horse-power per ton of weight — overload capacity. .
Number of motors
Normal capacity of each motor 550 h.p.
Normal capacity of each locomotive 2 200
Over-load capacity of each locomotive 3 300
Type of motors Gearless, bi-polar.
Type of control Sprague-General Electric multiple-unit.
Type of heaters for train supply Westinghouse oil-fired.
Air brakes Westinghouse graduated-release.
37 ft.
0
13 "
0
27 "
0
44
36^
94^ tons.
68A
a
26
(I
23
35
4
62
ft.
0
m.
50
iC
0
38
a
6
7
u
0
6
u
0
36
33
80 ELECTRIFICATION, SUBURBAN ZONE, N. Y. C. & H. R. R. R. [Papers.
Cars. — The suburban cars are constructed of steel and other non-
inflammable material, and, while simple in design, have all the features
conducive to the safety and comfort of the public. Their leading char-
acteristics are as follows :
Length, over all 62 ft.
Length of car body
Distance between truck centers
Distance between axles of motor trucks
Distance between axles of trailer trucks
Diameter of wheels — motor trucks
Diameter of wheels — trailer trucks
Number of motors on each motor truck 2
Normal capacity of each motor 200 h.p.
Normal capacity of motor car 400 "
Total weight of motor car 53 tons.
Total weight of trailer car 44^ "
Total weight of car body 33J "
Weight per motor car, due to electrical equipment. ... SJ "
Horse-power (normal capacity) per ton of weight of
electrical equipment 47
Seating capacity 64
Heating system Both steam and electric.
Lighting system Both electric and Pintsch gas.
Cooling system for summer season Two 14-in. electric fans.
Type of control Sprague-General Electric multiple-unit.
Acceleration, in miles per hour per second 1.2
Comparative Train Weights. — The comparative weights of steam
and electric trains in the two classes of service, through and suburban,
are interesting, as illustrative of the saving in consumption of energy,
and therefore in cost of operation, that accompanies the lower electric
train weights; and, also, as justifying the adoption of the multiple-unit
instead of locomotive practice for suburban operation.
Through Service.
Steam. Electric.
Tous. Tons.
Pacific type locomotive . . 171.0 Electric locomotive 94.5
8 Pullman cars 400.0 8 Pullman cars 400.0
Total 571.0 Totiil 494.5
Saving in favor of electric traction = 7Gi tons = 13 per cent.
PLATE XIII.
PAPERS, AM. SOC. C. E.
FEBRUARY, 1908.
WILQUS ON
ELECTRIFICATION OF SUBURBAN ZONE
OF N. Y. C. & H. R. R. R.
ELEcriue LoetumTtye S.3CjMt TfuUft-TOrM. lirT/94./S Toms.
/e*-e/ //c^c^ ^r^d rt?presenf ai-srsg^ coni/jfions o^ fregfher
Corrocfions muof be maefe for gr^t/e 3ncy cur^aft/ns of /rcKff
Fia. 1.— Train Braking Chart— Distance.
SL£:cr/f/cLocoMOr/y£-S 6 Cj^r TffAm-ToTAL ft^T. 2^338 Tons.
Corrections musf be/773c/^ forQrscfe3n<fcari'3fLfre offriScA
tr/7ef7 3pp//ecf fo snij ^/i^e/7 /ooaf/on. Carres ^ns p/offec^ from ^n
syeraffe o/'t^ /ri/mher of runs.
Fig. 2.— Train Brakfng Chart— Time.
Papers.] ELECTRIFICATION, SUBURBAN ZONE, N. Y. C. & H. R. R. R. 81
Suburban Service.
Average Number of Cars.
Electric Locomotive. Multiple-Unit Cars.
Tons. Tons.
Locomotive 94.5
4i steel trailer cars 200.0 4^ motor cars 238.5
Total 294.5 Total 238.5
Saving in favor of multiple-unit practice = 56 tons = 19 per cent.
Shops and Inspection Sheds. — The maintenance of electrical equip-
ment in a high degree of efficiency requires suitable repair shops and
inspection sheds, located where the dead mileage will be reduced to a
minimum. At both Harmon and North White Plains permanent in-
spection sheds have been built, and at the former point ample modern
shop facilities are provided. As the equipment on both divisions is
pooled, any car or locomotive needing repairs can be sent while in
regular service to either place, without the expense and loss of time
incident to special dead movements.
Interchange Terminals. — At North White Plains, the existing steam
engine-house plant is to be enlarged when the extension of electric
operation requires added facilities for the interchange of power. At
Harmon, space has been provided for ample facilities for the same
purpose. Owing to the present curtailment of electric operation because
of the backwardness of the State in acting on the abolition of grade
crossings north of the limits of the City of New York, temporary
terminals have been constructed, at High Bridge on the Hudson
Division and at Wakefield on the Harlem Division, with convenient
yard arrangements and structures for the care and exchange of power.
Operating Organization of Electrical Department. — The success of
a new plant of such magnitude, especially when a change from old to
new conditions must be effected without embarrassing an enormous
passenger traffic, depends very largely on the organization and per-
sonnel of the electrical operating force. It was recognized, at an early
stage of the work, that the operation and maintenance of the entire
installation required to deliver current to equipment, as well as the
maintenance of locomotives and cars, should be under the supervision
of those responsible for their construction, leaving to the regular steam
82 ELECTRIFICATION, SUBURBAN ZONE, N. Y. C. & H. R. R. R. [Papers.
organization the operation of trains with electric current and equip-
ment thus furnished.
As the work on the power stations, distributing system, and equip-
ment progressed, competent men were gradually employed for inspec-
tion and testing purposes, so that, when all was ready for regular
■operation, there was in existence a skilled, energetic corps of veterans,
■equal to any emergency, and imbued with a spirit that meant success.
Telephone System.- — A word should here be spoken of the independ-
ent telephone system which has been constructed for the purpose of
bringing all parts of the electric zone in close touch with each other
and with the load and train dispatchers.
Other Improvements. — While the principal purpose of this paper
is to give an outline of the elements of the electrification of the New
York Central suburban zone, it would be incomplete without at least a
passing mention of the other important improvements undertaken in
conjunction with the change of motive power.
Grand Central Terminal. — Within the territory bounded by Forty-
second Street, Fifty-seventh Street, Madison Avenue and Lexington
Avenue, the old Grand Central Terminal occupied a parcel of irregular
shape, with an area of about 23 acres. The four main tracks from the
north descend on grades of from 26 to 53 ft. per mile to the south end
cf the Park Avenue Tunnel at Fifty-sixth Street; thence they ascend
at the rate of 62 ft. per mile in an open cut in the middle of Park
Avenue to Fiftieth Street; thence spreading out into the yard, on a
slight descent to Forty-fifth Street; and thence on a gentle declivity
to the terminal in the train-shed near Forty-third Street. The vital
defect of this arrangement was the absence of switching tracks for
drilling the yard, north of Fiftieth Street, which necessitated the use
of two of the main tracks for that purpose. Consequently, the entrance
to the terminal really consisted of but two main tracks for the accom-
modation of the trafiic pouring to and from a four-track line. To
increase the congestion, one of these tracks, assigned to drilling ser-
vice, had also to be used for the storage of steam locomotives at rush
hours of the day.
By the use of electricity, it became possible to depress the roadbed
south of the low point at Fifty-sixth Street, so as to pass beneath the
surface of Park Avenue on either side of the railroad, and thus permit
the utilization of the full width of the avenue, 140 ft., without affecting
PLATE XIV.
PAPERS, AM. SOC. C. E.
FEBRUARY, 1908.
WILGUS ON
ELECTRIFICATION OF SUBURBAN ZONE
OF N Y. C. & H. R. R. R.
Fig. 3.— High Bridge Temporary Terminal.
Fi(i. 3.— Wakefield Temporary Terminal.
Papers.] eLECTIUFICATION, SUBUU15AN ZONL, N. Y. C. & 11. U. R. R. 83
its use by the public. This gave space for ten instead of four tracks
from Fifty-sixth to Fiftieth Streets, of which four are for a legitimate
main-line entrance to the enlarged upper yard, two are for drilling the
yard, and two on each side, or four in nil, ;ire for ingress and egress
of the lower-level suburban station. The upper level for through trains
will have stub tracks, while the lower level will have a double-track
loop at the south end near Forty-third Street.
The depression also admits of the extension of Park Avenue, for
its full width, south from Fiftieth to Forty-fifth Streets over the tracks
of the yard, and the connection by east and west viaducts of the ends
of streets from Forly-Hflh to Fifty-sixth Strcx^ts. inclusive, now sepa-
rated by the lonninnl.
To the 21? acres in tlio old (onniiial lins boon nddod by luirchase 17
acres, nuiking a total area of 40 acres. With the 21 acres obtained
by excavating for the suburban stiUion, there will be a total area in the
new terminal, when com]ileted, of more than 6i acres. This is equal
to an increase over the present space of 178 per cent.
These radical changes make necessary the tearing down of the old
station and train-shed, originally built in 1871 and enlarged in 1898
and 1900; and the substituticm of a nuicli larg(M- and handsomer struc-
ture, suited to the new motive power and more adequate for the proper
handling of a rapidly increasing tratlic.
It should here be added that electricity brings with it an unexpected
boom in the permissible use of overhead spaces termed "air rights,"
that is denied with steam traction. A vast area in the heart of the
greatest city on the continent is thus reclaimed for use as desired for
various revenue-producing purposes. In time, lliis feature will add
very largely to the company's assets.
An idea of the difficulties of construction, due to the nature of the
underlying material — solid rock — and the necessity of subordinating
all efforts to the safe and uninterrupted movement of an exacting and
constantly increasing train service, is illustrated in the accompanying
photographs.
Tlie magnitude of the now lerniinal, wliich has thus to be built
while trains and passengers i)onr in and out, is evident from the quan-
tities of material involved. A Iter Iteiug loaded on cars, 3 000 000 cu. yd.
of rock and earth are dispatclied, at times when the passenger service
will j)G™^it, to the Hudson Division, for building additional main
84 ELECTEIFICATION, SUBURBAN ZONE, N. Y. C. & H. R. R. R. [Papers.
tracks. In the construction of retaining walls, suburban stations, via-
ducts, subways, and tunnels, 100 000 tons of steel and 260 000 cu. yd.
of concrete are used, in addition to numerous other materials.
The final result will be an electrically operated station and yard
with quadruple the capacity of the old one, and with many appurte-
nances for usefulness and profit, that are additional to the parent
purpose of a railroad terminal.
Bronx Improvement. — At Mott Haven Junction, in the Borough of
the Bronx, 5.3 miles from the Grand Central Terminal, two four-track
lines, making eight tracks in all, merge into the single four-track stem
that leads to the terminal. With increased frequency of train service,^
the grade intersections at such an important junction are inadmissible
on tlie grounds of safety and non-delay to traffic. Therefore, plans
have been adopted and work commenced on the raising and lowering
of tracks by means of viaducts and tunnels, so as to effect trailing
junctions free from grade crossings.
The points of junction are to be moved south about | mile, to the
vicinity of the Harlem River; and, near the present connection, on
One Hundred and Forty-ninth Street, a new large overhead station is
to be built, with eight main tracks. This will permit the abandonment
of the old station at One Hundred and Thirty-eighth Street, and
remove another of the causes for congestion on the four-track entrance
to the Grand Central Terminal. Moreover, this new station will serve
the rapidly growing population in the Bronx, which is fast approaching
the half-million mark.
Elimination of Grade Crossings. — At the time of the decision to
proceed with electric zone improvements, there were, within that terri-
tory, forty-four street and highway grade crossings, the abolition of
which was deemed precedent to the commencement of electric opera-
tion. Of these, one-half were located within the city limits of New
York, and these, by agreement with the City, have since been carried
over the tracks. None of the remainder has yet been completed, owing
to the delay of the State authorities to make effective the provisions of
the statute governing grade crossings, and also owing to difficulties in
acquiring the necessary additional right of way. However, due to the
energetic action of the new Public Service Commission, decisions on
many of the crossings have been reached; and the remainder are
expected soon. The majority of these eliminations require either
PLATE XV.
PAPERS, AM. SOC. C. E.
FEBRUARY, 1908.
WILQUS ON
ELECTRIFICATION OF SUBURBAN ZONE
OF N. Y. C. & H. R. R. R.
Papers.] ELHCTlil I'lCATION, SUBUHBAN ZONK, N. Y. C. & II. U. K. It. 85
changes of the line of the railroad for considerable distances, as for
instance at Mount Vernon and White Plains, or the lifting of the
grade of the tracks so that the streets may pass under, as at Yonkers
and Tarrytown.
Local Improvements. — The elimination of grade crossings north of
New York City, and the growth of business, make obligatory many
extensive and costly local improvements, with new passenger and
freight stations and yards. The more important ones are at Yonkers,
Hastings, Tarrytown, Ossining, and Harmon, on the Hudson Division;
and at Mount Vernon, Bronxville, Tuckahoe, and White Plains, on
the Harlem Division. Features of the design of these new stations
are the avoidance, by means of subways and overhead bridges, of all
grade crossings of tracks by passengers; and the placing of the tops
of the local platforms on a level with the car floor,
Four-Tracking and Loops. — The anticipated increase in frequency
of train service with electric traction, and the urgent necessity of
removing causes of congestion in this important entrance to New York
City, make mandatory the construction of additional main tracks, so
that there will be separate tracks in each direction for high- and slow-
speed service; and, where possible, additional tracks for the exclusive
movement of freight.
In line with this policy, new main tracks are under construction
within the suburban zone, in conjunction with the elimination of grade
crossings and improvement of local facilities. The four tracks on the
Harlem Division are being extended from Woodlawn Junction to North
White Plains, with long middle sidings at frequent intervals, for the
passage of passenger trains around freights. The double and triple
main tracks on the Hudson Division, as far out as Harmon, are being
increased to four, and, at some places, as for instance between Spuyten
Duyvil and Yonkers, two additional tracks have been provided for the
exclusive use of freight trains. As on the Harlem Division, middle
tracks are being built, where needed, for keeping freight trains out of
the way of the passenger service.
At Harmon and North White Plains, loops are to be built, for the
turning of suburban trains without crossing the express traffic at grade.
It will be noted that, with loops at all three termini and the freedom
from grade crossings at Mott Haven Junction, opportunity is given for
a constant flow of traffic with an absence of the usual obstructions that
cause congestion.
8G ELECTRIFICATION, SUBURBAN ZONE, N. T. C. & H. R. R. R. [Papers.
Increased Capacity of Entrance to Grand Central Terminal. — From
the fact that two four-track lines feed into a single four-track stem
from Mott Haven Junction to the terminal, the question naturally
arises as to what solution the future holds for this restriction on
growth of traffic. The present plans of the terminal provide for a
future four-track cross-town tunnel connection with the West Side
line of the Company, over which the Hudson Division can then enter
the terminal without burdening the Harlem Division tracks. This,
when built, will afford to the terminal an eight-track entrance con-
nected with both train levels.
Improvements in Alignment and Grades. — In conjunction with
these radical "changes in the physical condition of the property, it has
been considered wise to make at the same time other desirable changes
that could not be accomplished later without undue extra cost. At
many places, on both divisions, alignment and grades have had careful
study, and alterations have been approved which will result in material
saving in rise and fall, and in curvature. Many have been completed,
and others have been deferred, awaiting the acquisition of right of way
and the settlement of legal questions. Among those still in embryo is
the improvement between Croton and Peekskill, more than 8 miles in
length, which when completed Avill admit of a still further extension of
electric operation.
The advantages to be gained by the principal changes of alignment
are as follows :
Marble Hill cut-off, including Spuyten
Duyvil Tunnel cut-off
Croton to Peekskill
Spuyten Duyvil to Mt. St. Vincent
Irvington cut-off
Totals 8 341 '' 559°
Signals and Interlocking. — Under the old order of affairs, traffic on
the Hudson Division from the north ran right-handed to Spuyten
Duyvil, where it was transposed to left-handed operation so as to
harmonize with the left-handed practice on the Harlem Division. The
design of the new Grand Central Termiuiil and a possible future con-
Saving in
Saving in
Distance.
Curvature,
3 944 ft.
137°
4 338 "
333°
9 "
24°
50 "
65°
PLATE XVI.
PAPERS, AM. SOC. C. E.
FEBRUARY, 1908.
WILQUS ON
ELECTRIFICATION OF SUBURBAN ZONE
OF N. Y. C. & H. R. R. R.
1 '1
!
►'k ■ %■ 9=*^
j;
L-. 1
b : Vr
J^^^
-' MiSk \
I-
iSS^iRASl
}-
V
^^Kxw^fjiall
Tl
'i|H|'. 1
4-
i, /^^SKP
33
, ^Hfe: '
'^"Si
1 , w^ ■
K
1 s -^^
- * ^\^l^
^■^
1 itflK
H
i 1 V
o
k"^
a. 1 IB „^^mM
w
" ■" ' ' — ^
*
'tfr -«Hir*>i' '
>■
0
o
""^j
' -9
H
-^ , ,-£y»
s-J
" M.-.
z
jxmmtik^i , 1
H
^^^^^v "'Sw . vftV
mKKHmd4'
t-
si^^^^k
H
^^^^ 1^1 **
H
^^^^^^^B^rF?
1>
./jMy
M^^/^yyimm
5;
|Ufi^V
mKk/////WM
MH^^^H
<i vQjfi^RluSik. '
ffl
^iSS^wvnu.
M
wSfmSw^^k^ '
O
„..'.^ 1*
^
l';i|)cis.] |.;ij.;("i'|;| |'|(!A'I'I()N, SIHUIL'l'.A N /ONI'l, N. Y. (!. & 11. If. U. It. 87
nection with the cil.y siibwny h.vsIciii, as well as (he dcsirMhilily of
avoiding tiic gradt^ crossing at Spuylcn Dnyvil, led l,o tho decision to
tnako llio riglit-lianded system of operation uniform throughout the
Hiihiirlian zone. In considering Ihr eifect of this reversal of traffic
on the existing signals and interlocking plants, it was also i-ealized
that the cuntrollcd-manual systc^m in use on a largo portion of the
territory was insufTieicuitly elastic for tho quick handling of a frequent
electric train scrvieo on four oi- nioi'e tracks. Aeeompanying these
traffic reasons for radical t^haiigcs in tho old signals and interlockings
was the ecpially important fact that the use of track rails for return
pro|)ulsi()n current, to tlu! i)ovv(!r stations completely dc'ranged the
signal circuits. Thcji, too, the many additions and changes to tracks
made imperative the abandonment of tho larger ])art oi, the old plants.
All these causes led to the adoption of new electric automatic sig-
nals and electric interlocking plants for the entire zone, the predomi-
nant feature of which is the reactance bond, which p(!rmits the free
j)assage of propulsion ciirreiit, through the track rails, but, where de-
sired, stops the passage of the altcM-nafing signal cnri'cait ci remit.
Fences. — One of the worst evils with which American railroads
have to contend is trespass. Kight of way and tracks are considered
public highways, and tho petty courts refuse or neglect to impose
adequate punishment on those who thus risk their lives in dangerous
places. This freedom of use of the railroad's property also leads to
thieving which, in the aggregate, causes large losses to the company.
'riw. change to electric traction by no means minimizes these evils.
More frequent trains, and the presence of electricity, increase the risks,
while copper cables and bonds attract the thief. To guard against Ihese
incrcas(!d dangers, tb(! entire; ((l(H;tric zone is to be enclosed with num-
and boy-proof fences. The portion within the settled districts consists
of iron pickets and concrete posts of a pleasing design.
Chronology.— -YoWowmg the placing of orders in tli(! fall of V.)OS,
work was pushed energetically on all items of construction required
for tho operation of the initial electric zone south of Wakefield and
High Bridge. It should be borne in mind that the larger part of the
work had to be p(!rfortn(ul on or about tracks congested with traffic,
which entailed danger to employees, dcjiay to numy parts of the work,
and ex])ense. It is a pleasure to record, however, that not an accident
occurred to regular train service, nor, with a lew minor (!Xce|)l ions, any
88 ELECTRIFICATION, SUBURBAN ZONE, N. Y. C. & H. R. R. R. [Papers.
delay to traffic, due to construction. Such accidents and delays as did
occur were from other causes.
The following dates mark the progress of the electrical features :
Initial informal test of first electric loco-
motive October 27th, 1904.
First formal test of Electric locomotive. . . . November 12th, 1904.
Port Morris Power Station :
Commencement May 15th, 1904:.
First current July 1st, 1906.
Transmission Lines:
Commencement February 17th, 1905.
Ready for service September 30th, 1906.
Sub-stations :
Commencement July 6th, 1905.
Ready for service September 30th, 1906.
Working Conductors :
Commencement January 2d, 1906.
Ready for service December 11th, 1906.
Electrical Equipment :
First operated in New York City... July 20th, 1906.
First train into Grand (^entral Ter-
minal September 30th, 1906.
Electrical Operation :
First schedule multiple-unit train. .. . December 11th, 1906.
First schedule electric locomotive. ... February 13th, 1907.
First regular shop train April 14th, 1907.
Completion of change of motive power:
Schedule trains July 1st, 1907.
Reversal of traffic August 25th, 1907.
Because of the burdensome conditions of traffic, and complicated
changes in the signal and interlocking systems, about 6 months were
thus consumed in making the change of motive power complete, after
the first schedule train was operated.
PLATE XVII.
PAPERS, AM. SOC. C. E.
FEBRUARY, 1908.
WILQUS ON
ELECTRIFICATION OF SUBURBAN ZONE
OF N. Y. C. & H. R. R. R.
Fig. 1.— Before.
Fig. 3.— After.
Contrast Between the S.vioke Conditions, as They Existed at the Grand Central
Terminal in 1906. and the Absence of S.moke in the New Terminal.
Due to the Use of Electricity.
Papers.] ELECTRIFICATION, SUBURBAN ZONE, N, Y. C. & H. R. R. R. 89
Initial Zone Operation. — As previously stated, the company was
forced to confine temporarily the change of motive power to the opera-
tion of the suburban zone terminating at High Bridge, Y miles out;
and at Wakefield, 13 miles from the terminal. This postpones for
two or three years the extension of electrical service to the northerly
termini of the suburban zone. In the meantime, the power on through
trains is changed at the temporary termini. At the same points, mul-
tiple-unit trains north-bound have steam locomotives attached and
thence proceed as non-electric trains; and south-bound the steam
locomotives are detached and the trains continue by electricity without
locomotives. The average time required for making the changes,
including that lost in slowing down and regaining speed is as follows:
Through trains with locomotives 4 J min.
Multiple-unit trains, north-bound 3 "
Multiple-unit trains, south-bound 2^ "
On the Hudson Division this delay has been largely compensated
by shortening the line at Marble Hill and the elimination of grade
track crossing at Spuyten Duyvil.
Eesults.
Expectations from Electrification. — Now that the change of motive
power in the initial electric zone has been completed for sufficient time
to gain at least a preliminary idea of the results, the question naturally
arises, with what success has the change met expectations ?
It has already been explained that the principal reasons for under-
taking the work were twofold:
(1). — Demand of the public for the abolition of the nuisances
incident to the use of steam locomotives south of the
Harlem River; and
(2). — Need for increased capacity of the terminal, by the elimi-
nation of a large proportion of the switching movements
required with steam locomotive practice; and relief to
the main line entrance to the terminal by reducing its
use for haulage of dead locomotives and cars to Mott
Haven.
90 ELECTRIFICATION, SUBUllBAN ZONE, N. Y. C. & H. R. R. R. [Papers.
As secondary considerations there were:
(3). — The possibility of sufficient economy in operation at least to
offset largely the additional fixed charges on the cost of
the electrical installation;, and
(4). — Opportunities for an ultimate large increase in traffic and
corresponding growth of revenue to justify the expendi-
ture for all improvements within the suburban zone.
What do the observations made thus far disclose?
The first two expectations have been completely realized.
Park Avenue Tunnel. — The atmospheric conditions in the Park
Avenue Tunnel show marked improvement, even with the presence of
the remaining New Haven Company's steam service.
Increased Terminal Capacity. — The effect on the operating effici-
ency of the terminal has been very gratifying, the increased capacity
being estimated at one-third. There has also been a large reduction in
the number of shop or "dead" trains to and from Mott Haven.
Reduced Cost of Opei-ation. — The results, as regards the third ex-
pectation, have been most surprising. The operation, for a considerable
period, of steam and electric equipment side by side has afforded an
unexampled opportunity for a true comparison of costs of operation.
Until now, data on this subject have been based on theory, ignoring
many of the indeterminate features of actual operation that have such
a weighty effect on costs. For instance, among the variables entering
into an analysis of this character are :
(a). — Cost and quantity of coal and water at the power station,
and on the steam locomotive tender;
(b). — Relation of ton-mileage of the motive power to total ton-
mileage, including motive power and cars;
(c). — Frequency and volume of traffic;
(d). — Mechanical and electrical desigTi of motive power as affect-
ing repairs, and hours available for active service;
(e). — Fixed charges, depreciation, and maintenance on all items
of both kinds of service, that have a bearing on compara-
tive results, including land, structures, and equipment.
In other words, to obtain a true comparison, observations must be
made under like conditions in a known service.
PLATE XVIII.
PAPERS, AM. SOC. C. E.
FEBRUARY, 1908.
WILGUS ON
ELECTRIFICATION OF SUBURBAN ZONE
OF N.Y. C. & H. R. R. R.
^^rrrs^^j
j::
■«ffrv„v,-. r iirpajra t ^•f'^^^^r'- X
Fui. 1. I'liMi'dSKL) liitiiNX Station.
<A -Kc- -..^
%'
Fig. 2.— Orthogkaphic View of Bronx Improvement.
Fig. 3. Tvi'KAL Gradk CiicissrNc Ki.imination. with ( »vi:hhioaii m
AND TRACK.S Beneath (University Heights).
Papers.] ELECTRIFICATION, SUBURBAN ZONE, N. Y. C. & II. R. R. R. 91
With this object in view, a typical steam switching locomotive,
engaged in terminal service, and a steam passenger locomotive, assigned
to road service, were each selected for observation in the same class of
traffic with electric locomotives. The terminal service embraced switch-
STEAM LOCOIVIOTIVES USED IN COMPARATIVE TESTS
Weight on drivers, working order 156 000 lb.
Weigbt on truck, working order 16 500 lb.
Wciglil; total of eujiue _191 500 lb.
Weighlof tender, loaded 118000 lb.
STEAM LOCOMOTIVE USED IN
ROAD TESTS.
CLASS-F-2-d.
(No. 1978.)
iniX-O^
-16 6Ji- !
:>s w}.
Weight on drivers, working order 152 500 lb.
Weight, total of engine 152 5001b.
Weight of lender, lo.lded
4DO0-gal. t.ank _..S9 5001b.
5100-gal. t.inU 915001b.
STEAM LOCOMOTIVE USED IN
SWITCHING AND HAULING TESTS.
CLASS B-10.
^ Fig. 3.
ing at the Grand Central yard, and hauling dead cars to and from
Mott Haven storage yard, a distance of 6 miles. The road service
comprised the hauling of schedule trains by the electric locomotive
between the Grand Central Terminal and Wakefield, 12^ miles; and
92 ELECTRIFICATION", SUBURBAN ZONE, N, Y. C. & H. R. R. R. [Papers.
the same trains by steam between Wakefield and North White Plains,
11^ miles.
Observers constantly rode the locomotives for the period of the
tests, namely, September 12th to 27th, 1907, in terminal service, and
October 4th to 18th, 1907, in road service. Cyclometers and watt-
meters registered actual distances, speeds, and current consumption.
Record was also kept of the number of cars switched and hauled, and
the proportion of time each day engaged in actual service, awaiting
duty, and laid up for inspection and repairs.
The coal used contained 14 000 B. t. u. per lb., and the cost, per
ton of 2 240 lb., was :
Steam locomotive in terminal service (anthracite) .... $5.00 per ton.
Steam locomotive in road service (bituminous) 3.50 " "
Port Morris power station (bituminous) 3.05 " "
Water, per 1 000 gal., cost as follows :
Terminal service and at power station 13 J cents.
Road service 5 "
The cost of electric current, when the power station designed load
is attained, is taken at 2.6 cents per kw-hr., delivered at the contact
shoes of the equipment, and includes all operating and maintenance
costs, interest on the electrical investment required to produce and
deliver the current, depreciation, taxes, insurance, and transmission
losses. The details of this cost are :
Items.
Operating costs.
Fixed charges.
Total.
Power station
$0.58
0.19
0.32
$0.44
0.15
0.92
$1.08
Transmission losses
0.34
Distributing system and .-iib-sta
1 24
Totals
$1.09
$1.51
$2.60
Locomotive wages are practically identical for each class of ser-
Table 1 shows the details of locomotive repairs, maintenance, and
fixed charges for each class of service, from which it will be noted
that, although the fixed charges and depreciation of the electric loco-
PLATE XIX.
PAPERS, AM. SOC. C. E.
FEBRUARY, 1908.
WILQUS ON
ELECTRIFICATION OF SUBURBAN ZONE
OF N.Y. C. & H. R. R. R.
PLATE XX.
PAPERS, AM. SOC. C. E.
FEBRUARY, 1908.
WILGUS ON
ELECTRIFICATION OF SUBURBAN ZONE
OF N. Y. C. & H. R. R. R.
Papers.] ELECTRIFICATION, SUBURBAN ZONE, N. V. C. & 11. H. R. R. 93
ffi
fCO
r-t
andl
tion,
char
tena
® (ti p.
■CO (t
o
S-S3
E
ing
inc
■ges
nee
ctur
»|
»!
and
ludm
and
of la
es
o
1
1
B IJ<? -•
P P x^
1
&5-£9
1
Total
Mott
day
4J4% on
5% on $
General
Runninj
Trips to
Use of s
1
1
"a ?
r .335 da
aven e
at We
g at Mc
1 shops.
- a v:
: g2S
if 1
■ "^Kt
-1
H
: o ps
: ^Sa
o'
. e cr
75 '^"-fl
Xi
: Jg 5"
;•£ ?
a:
. P5 to
H
. B 01
H
• rt- '^
>■
: - <_
S
■ CO o'
■ 05 (t
m
^ji^^
>
COOi l-^ *J
p3
O00 4i O
B O
0 d
^
^
e B
>4^
1-1 CO
^ ^
K
^
iffl to
OO ~>03
ca to
>(>. cnco
o
»i O-i
bi
o bi
s s'g
o
o c
CO p
l5^
o
CO C!
V- f^
-J *^
w
<».;;• H
5s- S
o^g2 2o^
a to ^
cct;- o
aiJJ CO ►
?e!; p o««
3 O ^ - o
c^« s
^^ffij.^s
S^5
=5
O
(T>
CO
• <i p
3§P^
O
; P <!
^Ci
•5'
• W P
ft re
~
: » p
P
3 '
3
. 01 c
5
: B. X
C-
r 1
: 5- §
B
:1 1
P ■
W
(T> .
p
a-
; s 8 :
2.:
1
p;
1
_^
t>*
^sg|
B o
^
^
^
C B
Oi
CO
t-1 >— .
3 <^
OS
to ■**
<I into
."•d ;
3
S 2
£ SS
%
P
P
*4^
tn to
£ 1
CJ>
|C>.
td
c
!^
o
H
M
r,
W
*]
w
m
H
Q
o
m
b
H
r/3
w
in
»«
1:1
>
>
H
Kl
i
§
r
y GO
% 5
O O
«^
? o
H
3:
O
M
o
o
o
94 ELECTKIFICATIOX, SUBURBAN ZONE, N. Y. C. & H. R. R. R. [Papers.
motive are higher than those of the steam, owing to the greater first
cost, the net result is in favor of the electric locomotive, due to lower
costs for repairs and maintenance. These results are based on actual
observations of the steam locomotive covering a period of several
years; and of the electric locomotive for two years on the experi-
mental track near Schenectady and one year in the New York zone.
The reasons for the lower cost of repairs on the electric machine are
the simplicity of construction and the minimum number of mechani-
cal parts. It is also worthy of comment that the electric locomotive
costs very much less per day for repairs and maintenance, due to lower
expenses for land and structures, and fewer days out of service. For
instance, the fixed charges and cost of maintenance and operation
of the extensive steam engine plant on costly land, are comparable with
the simple inspection-shed charges of the electric locomotive.
The Schenectady experiments indicated that the cost of repairs of
the electric locomotive of this type is about two-fifths of that of the
steam locomotive of a corresponding age and capacity.
The results of these observations are shown in detail in Table 2,
Plate XXI, and are summarized in Table 3. They show that, under
the stated conditions, the electric locomotive has the following ad-
vantages over its steam rival :
19% saving in locomotive repairs and fixed charges.
18% saving in dead time for repairs and inspection.
25% greater daily ton-mileage.
6% saving in locomotive ton-mileage in hauling service.
11% saving in locomotive ton-mileage in switching service.
16% saving in locomotive ton-mileage in road service.
12% net saving in cost in hauling service.
21% net saving in cost in switching service.
2Y% net saving in cost in road service.
Even better results may be expected during winter months, when
steam locomotives are subjected to many conditions that cause addi-
tional expenses not incident to the electric locomotive.
Reduced Cost of Grand Central Terminal Operation. — Owing to
the partial use of steam switching locomotives, and the presence of
the New Haven Company's steam road locomotives at the terminal,
the full benefits of change of motive power have not yet been secured.
PLATE XXI.
PAPERS AM. 300. C. E.
FEBRUARY, 1908.
WILQUS ON
ELECTRIFICATION OF SUBURBAN ZONE
OF N. Y. C. i H. R. R. R.
?tv.S£f.'^isf.v&^."'
96 ELECTRIFICATION, SUBURBAN ZONE, N. Y. C. & H. R. R. R. [Papers.
However, on the same wage basis for 1907 as for 1906, the month of
August, 1907, showed a decrease in cost of terminal locomotive and
yard operation of nearly $3 000, although the number of cars in and
out increased from 64 984 to 68 519. In other words, the cost of opera-
tion decreased 9% while the work done increased 5^%, which is
equivalent to a net saving of 13 J per cent.
Increased Revenue. — As to the fourth expectation — increased
revenue from a larger volume of business — no definite conclusions
can be reached until the extension of electrical service and the com-
pletion of the various other improvements afford an opportunity for
increase in frequency and speed of train service; for the production
of revenue from various sources at the terminal; and for the expansion
of business that is sure to follow the enlargement of the facilities of
the company throughout the suburban zone, not only as regards the
local service, but in an even larger degree from long-haul freight and
passenger traffic.
Summary of Results. — To summarize, the observations thus far
made demonstrate that this pioneer electric installation in heavy-
traction trunk-line work in the United States has fully accomplished
the purposes that prompted its adoption, namely :
(1).— Abolition of nuisances incident to the steam locomotive;
and
(2). — Increased capacity of the Grand Central Terminal,
a full year in advance of the date fixed by law; and in addition:
(3). — The promise, with the completion of the changes, of a
saving, in cost of operation, of from 12 to 27%, after pro-
viding for increased capital charges for electrification;
and
(4). — The outlook of a large future growth of remunerative
traffic, and other sources of revenue attendant on the use
of electricity, much more than sufficient to provide for the
increased capital charges for the other improvements.
Several years w;ill be consumed in the gradual rounding out of the
work as a whole; but it is gratifying to have this early indication of
the success of the undertaking from both the engineering and financial
standpoints.
PLATE XXII.
PAPERS, AM. 80C. C. E.
FEBRUARY, 1908.
WILQUS ON
ELECTRIFICATION OF SUBURBAN ZONE
OF N. Y. C. & H. R. R. R.
AUgmnent.
Highway (No's). J^^
Geography.
♦
Foldout
Here
♦ ♦
♦
I
Sub. Loop
"Grades
Vol. XXXIV. FEBRUARY, 1908. No. 2.
AMERICAN SOCIETY OF CIVIL ENGINEEES.
INSTITUTED 18. t 2.
PAPERS AND DISCUSSIONS.
This Society is not responsible, as a body, for the facts and opinions advanced
in any of its publications.
THE FLOOD OP MARCH, 1907,
IN THE SACRAMENTO AND SAN JOAQUIN RIVER
BASINS, CALIFORNIA.*!
By W. B. Clapp, M. Am. Soc. C. E., E. C. Murphy, Assoc. M. Am.
Soc. C. E., AND W. F. Martin, Jun. Am. Soc. C. E.
Introduction.
The Sacramento and San Joaquin Valleys were visited, in March,
1907, by one of the most destructive floods that have ever occurred in
California, the resulting financial loss being unquestionably greater
than that from any other flood of which there is record. The greatest
damage was done in the valleys of the trunk streams, especially Sacra-
mento Valley. The Lower Sacramento Eiver and its two largest
tributaries. Feather and American Elvers, reached the highest stages
ever recorded, and record stages were reached by other tributaries of
the Sacramento and by the San Joaquin and its tributaries.
The flood was remarkable in many respects. In the first place, it
was preceded by a period of heavy precipitation, and consequent flood
stages of all the streams, a condition which had prevailed intermittently
for several preceding weeks. As a result, the earth was thoroughly
*The data upon which this paper is based were collected by the VVater Resources
Branch of the United States Geological Survey in co-operation with the State ot Calitornia,
and the naner is nublishel bv oermission of the Director ot the Survey.
Further acknowledgments are due to Mr. J. H. Scarr, the district forecaster
of the United States Weather Bureau, and to the engineering department of the
Southern Pacific Railway, for data furnished.
tThis paper will not be presented at any meeting, but written communications on the
subject are invited foi publication with it in Transactions.
100 THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [Papers.
saturated, and all the surface basins which impound and store flood
waters temporarily were full. Particularly was this true of the large
flood basins on each side of the Sacramento Eiver. Then, too, this
flood was due to a general precipitation of extraordinary intensity
throughout the entire drainage basin (the storm covering a period of
several consecutive days), and also to comparatively high tempera-
ture and consequent rapid melting of snow in the higher altitudes.
This flood was remarkable, also, because of the record-breaking
stages of so many of the streams, such as the Lower Sacramento River
and the Feather, Yuba, and American Rivers. Not only were they
higher than ever known before, but they maintained their high stages
for a moderately long period. All the other streams of the water-shed
also maintained high stages for a like period, so that the resultant was
a flood of exceptional height and extent, and of considerable duration.
For the 4-day period, March 18th to 21st, the mean rate of run-oif
from the mountains and foot-hills of the Sacramento Basin alone was
about 530 000 cu. ft. per sec, or more than 22 cu. ft. per sec. per sq.
mile.
During this flood, special effort was made by the engineers of the
United States Geological Survey to obtain valuable flood data. The
flow of nearly all the important tributaries of both the Sacramento and
San Joaquin River systems was gauged in the foot-hills above the point
of debouchure. The flow from 83% of the mountains and foot-hills
in the Sacramento Basin was measured at eleven gauging stations.
In the San Joaquin Basin the flow from 41% of the mountains and
foot-hills was measured at six gauging stations. Unfortunately, no
gaugings were made of the San Joaquin itself.
It is believed that the data obtained during this flood will fully
repay the State of California for its generous co-operation with the
United States Geological Survey in the study of its water resources.
Data are now available for planning for these great valleys a more
comprehensive reclamation system than has been possible heretofore.
The importance of the data collected will be appreciated when it is
recalled that the rate of run-off from the mountains and foot-hills of
the Sacramento Basin alone for a period of 4 consecutive days, March
18th to 21st, was 112% greater than the rate used as a maximum by
the 1904 Commission of Engineers, after a careful study of all flood
data on record, including those of the 1904 flood. It is doubtful if
Papers.] THE FLOOD 0¥ MARCH, 1907, IN CALIFORNIA RIVERS 101
any combination of causes or conditions will ever produce a larger
rate of delivery of water to this valley for a 4-day period than occurred
during the flood of March, 1907.
Topography and Drainage of the Water-shed.
California is traversed, in a general northwest-southeast direction,
by two distinct and approximately parallel ranges of mountains which
extend almost the entire length of the State. Near the eastern border
is the Sierra Nevada; not far from the shore line on the west is the
Coast Kange. These two ranges merge into each other about 40 miles
south of the California-Oregon boundary line, the meeting point being
Mount Shasta, which has an elevation of 14 380 ft. They are merged
again south of Bakersfield by a cross-range known as Tehachapi
Mountains.
The elevation of the Sierra Nevada ranges from about 6 000 ft.
east of Mount Shasta at the north, to 14 501 ft. south of Yosemite
National Park where the range culminates in Mount Whitney.
Beckwith Pass, about 150 miles south of the northern boundary
line, is the lowest pass through the range, and has an elevation of
5 300 ft. The Coast Range is comparatively low, and is unbroken ex-
cept at Carquinez Strait and the Golden Gate which permit the drain-
age through Suisun Bay to reach the Pacific.
The Sierra Nevada and Coast Ranges, merging at the north and
south, inclose a water-shed approximately 58 000 sq. miles in area,
with a single outlet near the middle of the western side. This water-
shed is somewhat elliptical in shape, and has a length of about 540
miles from north to south and a width varying from 120 to 150 miles.
It is drained by two large river systems, the Sacramento in the north
and the San Joaquin in the south, and these are quite commonly re-
ferred to as the Sacramento and the San Joaquin River Basins.
Sacramento River has its source in the region of Mount Shasta,
and flows almost due south through the trough of the water-shed until
it discharges into Suisun Bay. The San Joaquin rises in the Sierra
Nevada, in the region of Mount Lyell, just east of Yosemite National
Park, at an elevation of 13 000 ft., and flows southwestward until it
emerges from the foot-hills into the trough of the valley, when it turns
and flows northwestward to its junction with the Sacramento near
Suisun Bay, through which the combined volume of the two systems
102 THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [Papers.
finds an outlet to the Pacific by way of San Pablo and San Francisco
Bays and the Golden Gate.
The drainage of the water-shed determines its division into three
distinct basins : On the north is the Sacramento Basin, 27 100 sq.
miles in area, drained by the Sacramento River and its tributaries; in
the center is the San Joaquin Basin, about 18 300 sq. miles in area,
drained by the San Joaquin and its tributaries (excluding Kings
Eiver, which, for reasons given later, is classified under the Lake
Basin) ; in the south is the Lake Basin, with an area of about 12 600
sq. miles, containing several lakes with their tributary drainage, but
at the present time having no outlet discharging to the sea.
That portion of the three basins which is inclosed by the sharply-
defined line of the foot-hills is called the "Great Valley of California."
This valley has a length of about 400 miles from north to south, an
average width of about 40 miles, and an area of probably 15 000 sq.
miles, and is surrounded by steep mountains. The western mountain
slope — that of the Coast Range — is comparatively narrow, having an
average width of about 18 miles. Considering the entire length of
the district, from north to south, the precipitation, as a whole, is light,
and perennial streams are few, but, in the region about Clear Lake
and Mount St. Helena, in the Lower Sacramento Basin, the precipita-
tion is remarkably heavy, and occurs almost entirely as rain. The
eastern mountain slope, which has an average width of about 58 miles,
is visited by rather heavy precipitation throughout almost its entire
length from north to south, particularly in the central part of the
Sacramento Basin. A large percentage of the precipitation occurs as
snow on the higher elevations. From this slope come all the larger
tributaries to the Sacramento and San Joaquin Rivers and the San
Joaquin itself, as well as the principal tributaries to the Lake Basin.
The change from mountain to valley is quite abrupt along a well-
defined line, but the slope of the valley is gentle and uniform.
What is commonly called the Sacramento Valley extends north-
ward only to Iron Canyon, near Red Bluff. In the Report of the Conl-
missioner of Public Works to the Governor of California, in 1894
(page 28), the valley is described as having a total area of about 4 250
sq. miles, divided as follows : 2 510 sq. miles of high lands, not sub-
ject to overflow; 450 sq. miles of lower lands, overflowed occasionally
by high floods; 1250 sq. miles of low lands, overflowed periodically;
Papers.] THE FLOOD OF .MARCH, 1907, IN CALIFORNIA RIVERS
103
d:.
4 .^-^' ¥■
ruylcL. Jw
MS
.^ ICei.
16 f-
LEGEND
+ tT.s. Gauging Stations
• U.S. Precipitation Stations
"V l'roi)Osecl Reservoir Sites
f-' Boundary of Watcr-slied
Scale of Miles
20 0 20 iO «0 80
190T
San Franciscb,
MAP OF WATER-SHED
OF
SACRAMENTO AND SAN JOAQUIN RIVERS
IN CALIFORNIA
SHOWING
TRIBUTARV STREAMS, UNITED STATES GAUGING AND
PRECIPITATION STATIONS,
AND PROPOSED RESERVOIR SITES
IN SACRAMENTO BASIN
104 THE PLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [Papers.
and 38 sq. miles of perennial stream surface. Below the mouth of
Stony Creek (Plate XXIli and Fig. 1) the central portion of the
valley is a flood piano of unusual extent, the immediate river banks
being from 5 to 20 ft. higher than the land on either side some distance
from the river. In the vicinity of the river banks the ground slopes
rapidly from the river toward the trough of the flood basins on either
side, but, as the bottom of the trough is approached, the slope becomes
more gradual. The lowest portions of the flood-basin troughs are from
2 to 7 miles from the river channel.
The large flood basin on the west side of the Sacramento is divided
into two smaller basins by a ridge of debris brought down by Cache
Creek. These are the Colusa Basin in the north and the Yolo Basin in
the south. The large flood basin on the east side of the Sacramento
is divided into foiir smaller basins by Marysville Buttes and the Feather
and American Eivers. From north to south, they are called Butte
Basin, Sutter Basin, American Flood Basin, and Sacramento Flood
Basin. Fig. 1 shows the position of the flood basins. The following
data regarding the area and capacity of these smaller flood basins are
taken from the Report of the Commissioner of Publi<3 Works to the
Governor of California, for 1894:
Colusa Basin is 50 miles long, from 2 to 7 miles wide, and has a
capacity of 690 000 acre-ft. at flood stage. It discharges into Sacra-
mento River above Knight's Landing through Sycamore Slough.
Yolo Basin has a length of 40 miles, an average width of 7 miles,
and a capacity of 1 115 000 acre-ft. at flood stage. It discharges
through Cache Slough into Steamboat Slough, and thence into the
Sacramento near the foot of Grand Island, about 25 miles above the
head of Suisun Bay.
Butte Basin is north of Marysville Buttes, and has an area of
from 30 to 150 sq. miles, depending upon the river stage, and a capacity
cf 460 000 acre-ft. at flood stage. It discharges through Butte Slough
into Sutter Basin.
Sutter Basin is south of Marysville Buttes and north of the Feather
River. It has an area of 138 sq. miles, and a capacity of 895 000 acre-
ft. at flood stage. It discharges through sloughs into Sacramento
River above the mouth of Feather River.
The American Flood Basin is south of Feather River and north of
the American. It has an area of 110 sq. miles, and a capacity of
PLATE XXIII.
PAPERS, AM, 30C. C. E.
FEBRUARY, 1908.
OLAPP, MURPHY AND MARTIN ON
FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS.
MAP OF
THE LOWER PORTION OF THE'
SACRAMENTO AND SAN JOAQUIN
VALLEYS
STATE OF CALIFORNIA
SHOWINQ
APPROXIMATE CONTOURS REFERRED TO MEAN SEA LEVEL.
FLOOD BASINS IN SACRAMENTO VALLEY, AND
THE MARGIN OF THE FLOOD PLAIN OF
MARCH. 1907
6 0 5 I'o Ifi
NOTK: The mai^ln of the flouil plane abown thus, [iwj;iiiU,tj
does not neceasarily indicate the area actually covered by water,
but It shows approximately the area which was below the \
surface In the river..
]
♦
Foldout
w Here
p"
♦
♦
Papers.] THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS 107
Climate.
The climate of California is probably one of its most valuable
assets. The principal factors affecting the climate are proximity to
the Pacific Ocean, and diversified topography. The warm Japanese
ocean currents, which bathe about 1 000 miles of the coast line, serve
to equalize the temperature as normally affected both by seasons and
latitude. The influence of the topography is such that altitude rather
than latitude is the chief factor affecting temperature.
As regards precipitation, the year is divided into two well-defined
seasons, the "rainy season" from November to March, and the "dry
season" from April to October. The rainy season is usually marked
by a series of storms, of greater or less severity, which form in the
Pacific Ocean and move eastward to the coast, depositing their moisture
before crossing the Sierra Nevada. The centers of the most severe
storms generally strike the coast in the State of Washington and then
move southward through Oregon into California between the mountain
ranges. These storms almost invariably make their appearance in late
winter or early spring, being, as a rule, most severe about the time of
the vernal equinox. At this season the precipitation is quite general
throughout the State, increasing with altitude and also with latitude.
Flood Conditions and Causes.
During the winter and early spring of each year, toward the end
of the rainy season, the various streams of the Sacramento and San
Joaquin Basins generally reach their highest stages. The most serious
flood conditions invariably exist on the lower courses of the trunk
streams, the Sacramento and the San Joaquin. On the Sacramento
River, in particular, serious damage is inflicted on crops and trans-
portation interests almost every year. Of course, the destructiveness
of any flood is measured largely by its height and duration. In these
basins the maximum height, and generally the greatest duration, of
floods on the primary streams result from the simultaneous flooding
of all the secondary and tertiary streams, a condition which obtains
when there is a period of long-sustained precipitation throughout the
entire water-shed, accompanied by high temperature and rapid melting
of snow on the higher elevations. It was such a condition that brought
about the flood of March, 1907.
108 THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [Papers.
Other conditions that contribute more or less to all floods in this
area are the following :
1. — The steep, barren, and impervious slopes of the mountains and
foot-hills, which result in streams of heavy grades and the rapid de-
livery of water to the valleys.
2. — The broad, flat valleys, with light grades and sluggish streams.
3. — The limited channel capacity. It is said that some of the
trunk channels are not large enough to carry even one-third of the
flood flow. Particularly is this true of the Sacramento River. Here
the surplus water overflows into the flood basins, the result being
either to increase or diminish the stage of the lower course of the river,
depending on the volume of water in the flood basins at the beginning
of the flood period and the duration of the period.
4. — The common outlet of the two river systems, with large tribu«
taries of each system discharging into trunk streams near this outlet.
5. — The constriction of the flood area in the delta of the two rivers
through the reclamation of large areas of overflow land by levees.
6. — The deposition of the debris resulting from hydraulic mining
in several tributaries of the Sacramento River, the result of which has
been the filling of channels and the reduction of gradients, there-
by raising the flood plane several feet.
7. — The tidal and wind action in the delta of the two rivers.
Precipitation.
In the Sacramento Valley, the mean annual precipitation varies
from 15 in. in the southern to 20 in. in the northern part, while, in the
tributary foot-hill and mountain areas, it varies from 20 to 60 in.,
with an occasional maximum of 100 in. In the San Joaquin Valley,
the mean annual precipitation varies from 10 in. in the southern to 15
in. in the northern part, and in the foot-hill and mountain areas it
varies from 15 to 40 in. In the Sierras, the greater part of the pre-
cipitation is normally in the form of snow, and the magnitude of
floods depends largely on its rate of melting. A heavy, warm rain on
a deep, freshly fallen snow produces a maximum run-off.
In January and February, 1907, there were two periods of heavy
and long-sustained precipitation, one from January 2d to 17th, and
the other from January 24th to February 4tli. The precipitation was
unusually heavy over the Sacramento Basin, diminishing gradually
Papers.] THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS 109
toward the south. The precipitation during the first of these periods
produced the ordinary winter stages of the tributaries of the Sacra-
rcento River; that during the second period produced flood stages on
the tributaries of both the Sacramento and San Joaquin Rivers and
high stages in the Lower San Joaquin. American and Bear Rivers
reached stages almost as high as in the great flood of the following
month. Yuba River was higher than at any time previously re-
corded.
In March there were two precipitation periods, one from the 2d to
the 11th, in which the amount of rainfall was moderate, and the other
from the 16th to the 25th, in which it was extraordinarily heavy. The
precipitation of the latest period was accompanied by unusually high
mean temperatures, especially in the higher altitudes, from the
Feather River south to the Tuolumne, causing very rapid melting of
snow and exceedingly large run-ofl. The average from 24 fairly rep-
resentative meteorologic stations throughout the basin shows that the
mean temperature for March 17th to 20th was about 5° above the mean
for the month, with low daily maxima resulting from cloudiness and
rain, and high daily minima due to the liberation of heat by the
storm. The average greatest daily range in this period was only 16
degrees. These facts indicate that probably all stations with a monthly
mean temperature as high as 25° had scarcely any freezing condi-
tions from March 16th to 20th, when the precipitation was heaviest.
Further, they show that, out of 113 stations located at various eleva-
tions throughout the Sacramento and San Joaquin drainage basins,
at 105 of them all the precipitation from March 17th to 20th was prob-
ably in the form of rain or of snow in a melting condition.
Table 1 shows the monthly precipitation from January to March,
1907, the daily precipitation for the three days, March 17th, 18th, and
19th, when it was greatest, and the precipitation for the ten days,
March 17th to 26th, for 120 places in the Sacramento and San Joaquin
Basins, varying in altitude from 20 to 7 017 ft., arranged according to
basins of tributary streams. Where possible, the monthly precipita-
tion for the period of January to March, 1904, is also given, for com-
parison with the great flood of that year.
Table 2 shows the average precipitation and average mean tempera-
tures for March at 113 'stations arranged according to stream basins
and in order of altitude.
110 THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [Papers.
Table 3 shows the results at 24 stations ranging in altitude from
60 to 5 270 ft., the data having been taken from the Climatological
Report of the United States Weather Bureau for March, 1907. These
particular stations were selected because they are the only ones in the
basin for which daily temperatures have been published. They are
fairly well distributed, both as regards area and altitude, and are prob-
ably as representative as any that could have been chosen. This table
also shows the extraordinary intensity of precipitation from March
17th to 26th by percentages with reference to the total for the month,
and also the normal for the month, covering a period of 21 years on
an average.
These tables show conclusively that the precipitation from March
17th to 26th, and particularly on March 17th, 18th, and 19th, was
phenomenally heavy for this section of the country. This large pre-
cipitation is rather evenly distributed throughout all the river basins,
but there is a very noticeable and quite rapid, though comparatively
regular, increase with the altitude. During the month, sixteen stations,
with elevations of more than 3 500 ft., had more than 30 in. in depth
of precipitation; about forty stations, with elevations of more than
1 500 ft., had more than 20 in. ; and fully one-third of the total pre-
cipitation for the month fell on March 17th, 18th, and 19th. On one
of these three days, seventeen stations, with an altitude of more than
2 000 ft., had precipitations of from 5 to 8 in. in 24 hours. It is note-
worthy that the range of temperature with altitude was quite regular,
and that there were no very low temperatvires even at very high eleva-
tions. It is highly probable that at elevations of 5 000 ft. a large part
of the precipitation occurred as rain or as snow which melted rapidly.
Indeed, at Inskip, in the Feather Basin, with an elevation of 4 850
ft., a 24-hour rainfall of 8 in. was reported. Taking a record of 21
years on an average throughout the basin, it is seen that about 88% of
the normal precipitation for March occurred on March 17th, ISth, and
19th, 1907, or, counting 20 days as normally rainy in this month, the
intensity of this 3-day period was about 600% of the normal intensity
for the month. During these 3 days the average precipitation at the
sixteen stations, principally in the Feather and Yuba Basins, having
more than 30 in. during the month, was 145% of the normal for the
month, or at an average intensity of 1 000% of the normal.
Papers.] THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS 111
TABLE 1. — Precipitation.
Rainfall IStatiosts.
Precipitation,
[N Inches.
g^j
2.^
a
m
A
M
^
.n
a^
No.
Name.
a
oi
■-5
^
3
3fl
t~
QO
OS
m
" o
S
fi
fa
g
o o
s
^
^5
S£
W
M
S
a
g
^-d
Sacramento Drainage Rasin.
1
Delta
1138
1904
1907
3.96
12.26
21.19
9.21
23.93
24.45
49.08
45.92
1.10
3.50
3.50
18.10
47.3=
2
Redding
565
1S04
1907
2.34
8. '57
14.10
9.09
15.89
7.28
32.83
24.94
1.36
0.88
0.11
4.57
49.0^
a
Dunsmuir
2 285
1904
1907
5.03
20.53
24.00
8.27
22.90
18.64
51.93
47.44
2.00
2.87
2.72
13.61
46.9°
4
SissoD
3 555
1904
1907
3.26
9.48
10.91
2.84
15.90
13.16
30.07
35.48
0.00
8.55
1.27
11.27
37.6°
5
Nimshew
2 0(10
1904
1907
10.82
17.64
8.72
13.12
13.27
27.69
32.81
58.45
5.54
4 00
3.03
18.36
42.4°
fi
Sacramento
71
1904
1907
0.15
4.63
5.26
2.37
5.43
7.28
11.14
14.28
0.42
1.74
0.56
4.75
50.9°
7
Fruto
624
1904
1907
0.75
6.43
6.13
1.95
7.07
4.67
13.95
13.05
0.45
0.40
0.30
2.90
50.1°
8
Shasta
1148
1904
1907
2.79
13.65
24.86
7.89
16.37
14.47
44.02
36.10
1.54
3.25
1.03
10.98
48.0°
9
Corning
377
1904
1907
0.60
3.60
4.95
2.60
7.30
5.05
12.85
11.25
0.00
0.95
0 28
2.68
49.1°
10
Red Bluff
307
1904
1907
1.44
6.10
6.63
3.13
8.33
5.92
16.40
15.15
0.62
0.38
0.00
2.93
48.4°
11
Tehama
220
1904
1907
1.01
4.75
4.6r
2.96
7.19
5.38
12.87
13.09
0.86
0.28
0.30
2.':9
50.8°
13
Chico
189
1904
1907
0.80
6.28
5.64
2.09
9.33
8.08
15.77
18.67
1.58
0.73
0.36
4.79
49.2°
13
Durham
160
1904
1907
1.70
6.45
5.75
2.09
10.32
8.39
17.77
16.93
1.61
0.87
0.45
4.49
50.4°
14
Willows
136
1904
1907
0.45
4.84
3.44
1.02
7.61
3.63
11.50
9.48
0.70
0.13
0.05
1.98
49.1°
15
C(jlusa
60
1904
1907
0.66
5.63
3.13
0.75
5.67
3.80
9.46
10.18
0.58
0.22
0.00
2.21
49.9°
16
Suisun
20
1904
1907
1.12
8.89
6.50
3.59
7.52
7.57
15.14
20.05
1.61
0.08
1.55
5.95
52.0°
17
Dunnigan
65
1904
1907
0.66
7.63
5.33
1.63
8.87
6.98
14.86
16.24
1.10
0.04
1.40
3.91
52.9°
1H
Wesi Branch
3150
1907
17.96
39.69
112 THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [Papers.
TABLE 1.— (Continued.)
Rainfall Stations.
Precipitation, in
Inches.
1
a
ai
^'
xJ
Jh'
.a
-M
«'
S
«
-g
^^
>
0)
Q
1-5
ta
g
hI
3
c6
S^
H
CO
S
^
g
ss
No.
Name.
McCloud Kiver Drainage Basin.
19 Johns Camp.
1904 4.50 19.73 37.36 51.49
Pit Kiver Drainage Basin.
^0
Csdarville
4 675
4 460
1904
1907
1907
1.12
1.99
1.35
4.87
3.70
2.87
4.61
3.31
4.13
10.60
9.00
8.35
0.67
0.55
0.40
0.75
0.06
0.14
1.59
2.45
?I1
Alttiras
34.4"^
35.6°
Feather River Drainage Basin.
9f?,
Magalia
2 321
1904
1907
3.43
23.57
23.39
10.71
30.13
37.75
56.95
73.03
7.65
6.66
2.79
24.48
41.9°
9^
Oroville..
250
1904
1907
1.60
6.71
7.99
3.59
10.86
10.90
20.45
21.20
1.10
1.44
0.52
5.57
51.00
9A
Butte Vallev
4 030
3 600
1904
1907
1904
1907
4.30
11.96
2.39
9.57
22.90
6.78
18.81
4.48
22.10
26.76
15.53
24.51
49.20
45.50
36.73
38.56
Greenville
25
4.25 6.17
2.91
19.89
37.8*
9.P,
4 730
3 400
1904
1904
1907
4.13
2.46
11.89
29.10
23.10
4.96
29.90
10.83
30.15
63.13
35.39
47.00
4.40
25.55
97
5.30
6.50
35.8°
•■'8
4 850
1907
45.30
"9
Bless
98
1904
1907
1.09
4.55
4.98
1.85
8.35
6.57
14.42
12.97
0.20
0.00
0.00
3.65
52.0»
30
Brush Creek
2 140
1904
1907
4.81
16.21
23.11
11.49
25.01
33.02
58.93
60.72
5.70
5.40
3.40
23.96
42.8°
31
67
1904
1907
1.19
4.52
5.18
4.30
7.77
10.59
14.14
19.41
0.30
1.30
2.00
6.44
53.8<>
391
213
1904
1907
1.48
5.86
7.23
3.34
9.35
8.80
18.05
17.50
0.97
0.86
0.25
4.37
50.8°
'«
Sterling City
3 535
1904
1907
3.96
24.63
26.51
17.54
25.22
4:^.38
55.69
85.55
6.66
7.90
6.16
32.86
37.0°
Papers.] THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS
TABLE 1.— {Continued.)
113
Rainfall Stations.
Precipitation,
IN Inches.
0) u
a
TD
^'
.d
A
.c
as
No
Name.
c8
6
s
®
iL,
0 o
CO
00
OS
^^
•*^ o
a-"
>
ft
i-s
El.
^'
e8
1
h
cj
s
^i
SB
Yuba Eiver Drainage Basin.
34
Colgate ^.
650
1650
2 580
3 200
5 939
7 017
5 000
3 400
3 250
1904
1907
19(14
1907
1904
1907
1904
1907
1904
1907
1904
1907
1904
1907
1907
1907
1907
1907
1907
1904
1907
3.79
7.86
3.79
10.54
2.76
10.21
3.85
10.25
5.20
14.70
4.20
13. SO
4.48
17.75
18.75
12.11
5.37
13.82
9.92
10.28
14.04
8.98
19.17
8.22
16.44
9.23
30.80
6.25
30.40
4.38
30.35
16.40
16.78
12.87
11.26
45.61
12.68
8.19
19.31
13.65
19. 4S
18.64
24.62
21.89
28.64
26.87
24.20
21.30
37.36
31.66
42.62
36.12
37.38
36.93
26.78
29.01
39.51
31.46
21.90
37.45
31.48
38.95
40.57
43.05
42.18
48.12
62.87
45.15
55. 9(.
45.24
66.49
76.27
Dobbins
35
2.50
2.47
3.07
1.00
1.42
6..58
2.33 2.60
3.34 3.63
4.51 3.97
1.C0 3.60
2.42 2.32
6.19 5.42
13.04
17.76
21.10
14.10
16.06
.33.12
36
Nevada City
37
No. Bloomfleld
41.6^
38
Cisco
39.8°
39
Summit
34.4'=^
40
La Porte
28.8°
41
32.2°
\9.
Woodleaf
69.00
43
Deer Creek...
44
45
6 500
5 500
52.38
90.49
57.96
46
Bowman's Dam.
Bear Eiver Drainage Basin.
47
Bear Valley 4 600
Wheatland ,
Grass Valley.
Gold Run
84
2 090
3 222
1904
1907
1904
1907
1907
1907
4.46
14.59
1.09
4.67
11.22
10,47
34.26
11.10
6.14
3.06
11.79
9.61
27.99
35.50
7.22
9.64
26.15
21.61
66.71
61.19
14.45
17.37
49.16
41.69
1.18
0.81
6.19
50.0°
39.4°
114 THE FLOOD OF MAECH, 1907, IN CALIFORNIA RIVERS [Papers.
TABLE 1.— (Continued.)
Rainfall Stations.
a
o
No.
Name.
^
tt)
OJ
P
H
Precipitation, in Inches.
PS
S5
Ho
0) g
American Kiver Drainage Basin.
51
Colfax
2 421
1904
1907
3.50
9.45
20.10
9.75
30.46
19. 4f;
44.06
38.66
2.401.55
2.85
12.36
48.3°
5'i^
Emigrant Gap
5 230
1904
1907
3.75
14.35
25.10
14.45
31.23
30.2(1
60.07
59.00
2.00 3.50
4.50
19.45
30.0°
53
Georgetown
2 650
1904
1907
4.79
8.96
36.02
13.50
31.17
39.07
51.96
51 .53
3.581.08
4.90
19.47
42.4°
54
Placerville
2109
1904
1907
2.96
8.13
15.59
8.15
13.4^
30.54
33.03
36.82
3.03 1.06
4.28
14.62
47.0°
55
Rocklin
249
1904
1907
1.29
5.51
7.94
5.71
3.1!r
12. 4t
16.41
23.68
1.70
0.15
2.20
8.65
51.2°
56
Represa
Auburn
305
1360
1904
1907
1904
190?
1.15
6.31
2.73
8.35
8.33
5.31
13.34
9.70
8.55
12.39
11.8.-
16.66
18.03
34.01
27.90
31.71
57
3.08
0.39
3.11
11.23
47.6°
58
Blue Caayon
4 395
1904
1907
4.81
13.18
30.61
17,95
26.14
35.1]
61.56
66.34
4.18 4.35
6.45
37.33
36.6°
59
Iowa Hill
3 825
1904
1907
4.58
11.53
20.20
10.13
16.97
24.36
41.75
46.01
3.43 2.88
3.21
16.35
42.6°
60
New Castle
970
1904
1907
1.93
7.09
10.79
6.73
11.61
14.10
24.33
27.91
1.35 1.18
1.78
8.49
50.0°
61
Eolsom
252
1904
1907
1.12
5.25
7.19
5.65
7.70
11.06
16.01
21.96
1.42 0.10
2.08
7.33
51.0°
a?.
Pilot Creek
4 000
3 704
1904
1907
ir.04
1907
5.48
14.40
3.84
9.45
29.88
11.79
35.50
13.24
25.45
32.88
23.29
24.05
60.81
59.07
52.63
45.74
Towle
63
3.69
15.83
2.402.43
i
37.7°
Stony Creek Drainage Basin.
65
Fouts Springs
1650
750
254
1904
1907
1904
1904
1907
2.34
14.8;.
0.75
9.44
4.60
4.79
4.06
12.73
15.63
6.22
6.36
3.97
24.51
35.08
11.76
Julian
Orland
0.57
0.15
0.12
2. Hi 48.8°
1
Papers.] THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS 115
TABLE 1.— (Continued.)
Kainfall Stations.
Precipitation,
IN Inches.
g
aj
J3
j= ja
ja
2*-
No
Name.
1
a
■^ b.
o o
t- a
M
00
03
tJ'-O
-^ o
a*-
o
1-5
fc g
^
s
^5
^2
Cache Creek Dkainage Basin.
Bartlett Springs 2 375
KonoToyee 1350
Lake Port 1325
Upper Lake 1 350
Guinda 350
Woodland
1904
2.48
19.96
16.75
39.19
1904
1.64
8.78
7.62
:8.04
1904
1.65
13.37
12.72
27.74
1904
1907
1.62
5.30
11.19
4.60
10.14
10.63
2i.95
20.53
2.40
1.73
0.70
7.98
1904
1907
0.75
9.30
6.80
1.30
7.55
8.84
15.10
19.44
1.30
1.00
1.70
7.20
1904
1907
0.69
4.45
4.60
3.24
7.15
5.90
12.44
13.. 59
4.10
i
47.6°
47. 9»
50.50
PuTA Creek Drainage Basin.
73
Middletown
1 300
51
1904
1904
1907
2.52
0.53
4.81
16.99
5.05
2.28
27.57
7.57
6.69
47.08
13.15
13.78
1.25
0.07
2.00
5.24
74
Davisville
56. lo
75
North Lake Port
1450
363
1907
1904
1907
5.45
2.65
10.89
4.30
16.08
7.95
12.35
16.10
19.50
22.10
34.83
38.34
76
Calistoga
0.00
5.80
3.85
16.60
52. 6»
77
Helen Mine.
2 750
1904
1907
4.52
27.21
34.22
11.66
31.48
36.73
70.22
75.60
7.40
6.64
5.10
28.90
43.4°
78
VacavUle
175
1904
1907
1.67
6.54
8.61
3.08
11.73
8.48
18.10
0.13
2.02
0.29
4.81
49. 7°
79
Mt. St. Helena . . .•
2 300
1904
1M07
3.37
19.95
28.34
12.18
26.14
24.20
57.85
56.33
116 THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [Papers.
TABLE l.—iContinued.)
No.
Rainfall Stations.
Name.
Precipitation,
IN Inches.
,to
si
,q
^'
.a
— ^a
■^
. +5
n
c3
►-5
.o
b
nt
00
^^
fe
S
^n
s
^5
05
S
a
a
Acs
as
J^ :g^
San Joaquin Drainage Basin.
80
Farmlngtoii
Fresno
Ill
293
1904
1907
1904
1907
0.54
4.70
0.57
3.35
4.71
2.65
2.49
0.84
4.10
5.47
2.f5
1.74
9.35
12.82
5.81
6.03
52.9°
81
0.12
0.00
0.32
0.56
52. 8»
H?,
255
1904
1907
1.15
4.40
2.60
0.77
2.90
5.56
6.65
10.73
0.00
0.45
0.00
2.96
47.3°
RS
Las Banas
121
1904
1907
0.25
8.17
1.23
1.17
1.28
4.39
2.76
8.73
0.00
0.45
0.67
2.78
53.0°
84
Mendota
177
1904
1907
0.20
2.83
1.70
1.31
1.26
1.79
3.16
5.93
0.00
0.03
0.00
0.64
55.5°
85
Merced
173
1904
1907
0.55
4.25
2.30
3.16
2.34
3.68
5.19
11.00
0.00
0.00
0.22
2.73
51.7'
86
Newman
91
1904
1907
0.23
3.35
1.51
1.49
2.33
3.82
4.07
8.66
0.15
0.00
0.67
2.42
51.8°
87
Stockton
23
1904
1907
0.54
3.94
4.09
2.52
3.67
6.03
8.30
12.49
0.63
0.06
1.22
4.07
51.2°
88
Storey
296
1904
1907
0.69
2.70
2.69
0.48
2.47
1.35
5.85
4.53
0.00
O.CO
0.01
0.47
49.8°
89
Tracv
64
1904
1907
0.46
3.22
2.10
1.70
1.93
5.04
4.49
9.96
0.00
0.00
0.70
2.75
48.0°
t)0
Westley
90
1904
1907
0.41
5.18
1.53
1.39
3.07
3.55
5.01
10.12
0.00
0.18
0.48
2.31
55.2°
«)1
No. Fork
3000
345
25
46
1904
1907
1907
1907
1904
1907
10.73
14.30
4.24
4.64
4.65
6.43
■27;9i
9.30
9.76
7.72
11.46
Pollasky
Lathrop
9.19
4.20
3.58
0.42
3.23
4.42
0.86
1.54
2.65
1.80
W
93
41.5°
94
Antioch
0.65
0.03
0.83
4.38
.54.8°
Papers.] THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS 117
TABLE 1.— (Continued.)
Rainfall Stations.
Precipitation,
IN Inches.
tteS
.
HSS
a
m
A
^ ja
j:
« t.
—'.a
a£
No
Name.
^
1
?
^
aj
cS
|o
h"f
>
^
b.
s
Hp
b
03 eS
nJi
a
CO
s 1 s 1 a
CosuMNEs Drainage Basin.
95 Shingle Springs 1 427
1904
1907
2.80 15.91
5.05 8.50
J2.58
16.84
31.29
30.39
MOKELUMNE RlVER DRAINAGE BASIN.
9f
Mill Creek
3500
1 500
725
1560
2 326
49
287
35
1907
1904
1907
1904
1907
1904
1907
1904
1907
1904
1907
1904
1907
1904
1907
10.20
2. OS
6.25
2.61
7.47
2.44
7.61
4.62
9.38
0.60
4.00
0.90
4.87
0.72
3.94
8.00
13.79
6.25
13.92
5.15
13.35
6.29
IB.S*?
6.66
6.24
3.29
7.05
3.95
5.77
2.82
24.45
9.22
13.85
9.50
18.01
9.52
15.66
13.4?
19.76
5.27
7.59
5.00
10.39
4.85
6.76
42.65
25.09
26.35
26.03
30.63
25.31
29.56
34.47
35.80
12.11
15.38
12.95
19.21
11.34
2.06
2.36
4.04
15.96
41. 5»
97
Kennedy Mine
Electra
98
0.26
4.55
0.47
10.04
99
Mokelumne Hill
West Point
53.2°
48.0°
100
Gait
101
1.00
1.10
0.04
0.11
0.21
1.47
2.40
1.18
5.92
6.27
4.26
102
1(«
Tone
Lodi
51.3'
44.9»
13.52
0.42
50. 70
Calaveras Drainage Basin.
101
Milton
660
673
300
1904
1907
1904
1907
1907
0.93
4.76
1.42
5.51
6.78
2.53
10.56
4.31
2.61
5.30
9.27
7.81
11.12
9.38
13.01j
16.560.34
19.79;
20.94 0.92
0.35
0.25
1.53
2.62
4.90
6.66
105
Valley Springs
51.2°
106
54.2°
118 THE FLOOD OF MARCH, 1907, IN CALIFOEXIA RIVERS [Papers.
TABLE 1.— (Continued.)
Rainfall Stations.
Precipitation, in Inches.
No.
Name.
1
>
a)
.
P
a
w
<;
o o
CO
!>
s
g
1
si
.a
^ 1.
■" o
Stanislaus River Drainage
]Jasin.
107
Oakdale
156
760
7 500
1904
1907
1907
1907
0.70
3.72
5.03
11.38
5.00
2.36
6.49
2.63
3.44
6.37
17.48
29.43
9.14
12.45
29.00
43.44
0.59
0.00
1.33
3.36
108
Melones
Relief Creek
49.1°
109
Tuolumne River Drainage
Basin.
110
111
112
113
114
115
llli
Jamestown
1 471 1904
• 1907
3 100 ' 1907
1
4 452 1904
|1907
1
3 100 1907
i
850 1907
91) 1904
1907
1 900 1904
1.96
7.82
- 9.89
1.87
13.49
9.66
5.76
0.33
4.11
1.79
7.38
12.96
5.59
4.92
17.10
5.82
3.70
4.54
1.67
3.00
13.82
5.40
8.18
17.27
30.79
19.56
27.41
15.95
13.38
3.15
4.70
8.63
19.09
23.10
30.58
35.60
38.53
46.73
29.31
23.68
4.15
11.81
24.24
31.87
1.04
1.43
1.83
10.68
Tuol Camp
49.0°
Crocker's (Sequoia P. 0.).
Modesto
0.34
1.41
1.05
1.46
0.76
1.93
3.64
12.17
57.3°
1907
47.4°
Merced River Drainage Basin.
117
118
Summerdale
Yosemite
5 270
3 945
375
126
1
1904 2.60; 14.96 17.09
1907: 14.95 6.81: 37.06
1904 2.99 13.95 12.53
1907 11.96 3.72' 21. 9S
1
1907| 4.04 2.08 5.85
1
1904' 0 57 2.19i 3.17
34.66
48.82
29.47
S6.66
11 97
2.r4
0.71
1.90
1.85
13.90
35.2°
119
2.61
3.02
13.15j 38.4°
1-'0
Elm wood . .
4.93
0.22
1.64
1907'i 3.60 0.60 3.26
7.46
0.00
0.00
53.6°
Papers.] THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS 119
TABLE 2. — Rainfall Stations, x\ccording to Elevation,
FOR March, 1907.
ELE.VATION, IN FeET.
0-500
46
Stations.
!
500-1 000 1 000-2 000 3 000-3 000
10 13 16
Stations. , Stations. Stations.
3 000-4 000
15
Stations.
4 000-5 000
7
Stations.
5 000-
6 Sta-
tions.
Basin.
SB ig
t^ IS
ft -
6.20 50.3°
9.22 51.9°
a
o
ft
3
S a
a
a
o
If
ft
19.46
^ Mean
? temperature.
to
^ Total
~ precipitation.
3
it
s ft
E
a
o
ft
26.42
32.68
34.77
21.61
28.46
3
II
S
<u
37.6°
36.9°
39.8°
39.4°
37.7°
d
.2
J.
t
il
IE
B
1
E
ft
5.98^49.6°
44.6°
43.4°
41.6°
4516°
Keatner
35.38
35.70
26 15
36.03
42.62
35.50
35.11
32! 2°
Yuba
i9.3i'
19 43
28.01
Bear
9 t;4 50 6°
American
11.97 51.1°
14.16 50.6° 16-66
47.6°
33.36
36.6°
30.20
16.84
14 76
Mokelunine
8.25 49.0°
9 38 ...
18 0rP3.2°
48.0°
19.76
24.45
41.5°
Calaveras
10 20.52 7°
Stanislaus
6 37 49 1° 17 48
29.43
Tuolumne
4.70 57.:^°
4.5« 53 (5°
13 38
18.18
48.3°
30.79
... .
15.95
20.98
38 '.4°
27.41
27.06
.35! 2°
Merced
San Joaquin
4.12 51.2°
3.97 48.8°
7.37 49.2°
11.56|52.8°
14.30
Stony Cr.
6.22
15.63
10.63
12.35
Cache Cr... .
47.6°
PutaCr
30.46
43.4°
28.66
38.3°
34.25
34.7°
Average of all \
Stations ')
6.65 51.0° 13.09 51.6°
i
16.36
48.2°
25.34
43.9°
28.61
A comparison of the precipitation from January to March, 1907,
with that for the same period and stations in 1904, shows that, for the
average of all stations in the water-shed, the precipitation was greater
in 1907 than in 1904, and that the difference increases from the north
toward the south, but the percentage in favor of the former is quite
small. An examination of Table 1 shows that the precipitation for
January, 1904, v;as quite light compared with that of January, 1907,
while the precipitation for February, 1904, was much heavier than
for February, 1907. The comparison for March, however, is of most
importance, as regards the floods of 1904 and 1907. Such a com-
parison is made in Table 4, where it is seen that, with the exception
of the Sacramento River Basin, the precipitation throughout the water-
shed was much greater in 1907. In the basins of the tributaries of the
Sacramento River from the east, the rainfall in March, 1907, was
from 20 to 41% greater than in March, 1904, while for basins on the
vrest it is only from 2 to 3% greater. For the San Joaquin River
and its tributaries tjie percentage is much greater, ranging from about
50 to 80 per cent. The distribution of the precipitation during the
120
THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [Papers.
TABLE o. — Resitlts at Twenty-four Stations. Ranging rx
Altitude fkom 60 to 5 270 Feet.
Drainage.
I
-i
o
o
Precipitation
IN March, 1907.
Temperature.
Month.
March
17th-26th.
March
17th-i9th.
Month.
March
17th-20th.
station.
**
c
0/
s
o
up
W) .
be .
tvH
S u
a
a
go
5
a
a
t
^ o
P^
s:-
g.
hJ
H
c3
CL, O
Alturas
Pit
3
4.13
59
35
35.6^
43. 0»
13°
Auburn
American. . .
36
16.66
224
67
33
107
47.6°
45.8°
19°
Cedai-ville
Pit
13
3.31
124
48
16
37
34.4°
42.0°
19°
Chico
Sacramento.
Sacramento.
37
24
8.03
3.80
197
28
60
58
32
21
95
27
49.2°
49.9°
53.1°
57.2°
16°
Colusa..
18°
Fresno
San Joaquin
20
1.74
32
32
25
33
52.8=
58.1°
18°
Greenville
Feather
13
24.51
371
81
54
254
37.8°
40.5°
14°
Merced
San Joaquin
33
3.68
1.56
74
6
15
51.7°
52.5°
25°
Milton
Calaveras. . .
Yuba
17
15
9.27
24.62
133
193
53
69
24
38
56
111
51.2°
41.6°
58.3°
48.2°
13°
Nevada City. .
19°
No. BlmHd....
Yuba
1(1
28.64
254
74
44
1.56
39.8°
45.5°
23°
Palermo
Feather
IB
8.80
247
50
23
80
50.8°
55.5°
17°
Quincy
Red Bluff
Feather
la
30.15
3.53
85
54
244
35.8°
41.4°
16°
Sacramento.
30
5.92
81
50
15
27
48.4°
52.2°
10°
Redding
Sacranifiito.
3^
7.28
53
63
32
49
49.0°
52.9°
10'
Sacramento...
Sacraiiit'iito.
30
7.28
148
65
37
92
50.9°
56.6° 12°
Shasta
Sacramento.
11
14.47
167
76
33
88
48.6°
47.4°
19°
Stockton
San Joaquin
36
6.03
164
67
30
79
51.2°
.57.4°
18°
Summerdale .
Merced
11
27.06
194
51
17
50
35.2°
39.4°
9°
Upper Lake..
Wheatland. . . .
Cache
as
10.63
238
75
45
152
49.6°
50.8°
16°
Bear
ao
9.64
247
64
33
109
50.6°
56.7°
17°
Willows
Sacramento.
28
3.63
119
55
24
53
49.1°
54.7°
17°
Yosemite
Merced
3
20.98
63
31
38.4°
39.5°
17°
Georgetown..
American . . .
34
29.07
209
07
33
102
42.4=
Average of a
bove 24 Sta-
tions
!
21
12.43
179
63
31
87
45.5°
50 7° ; 16°
Average of 7
Stations in
Basin
12.96
185
46.5°
1
Note :— These selected stations are fairly representative as regards both temperature
and precipitation. It is observed that the average of the mean temperature, March 17th-
20th, is 5.2° above that for the month.
month, however, is of most vital significance. For March, 1904, the
precipitation is distributed quite evenly throughout the entire month,
though the intensity is noticeably greater during the equinoctial week.
For March, 1907, however, not only is the total precipitation for the
month considerably greater than in 1904, but its periodic occurrence
in a series of storms is more pronounced. During the 10-day period
centering about the equinox, the intensity was so great that about 70%
of the total precipitation for the month occurred in this time, while
more than 30% of it was recorded on March 17th, 18th, and 19th.
Papers.] THE FLOOD OF MAECH, 1907, IN CALIFORNIA RIVERS 121
TABLE 4. — Comparison of Precipitation in Sacramento and San
Joaquin Basins, for March, 1904, and March, 1907.
River basin.
Number of
precipitation
stations.
Precipitation.
Percentage op
Difference.
1904.
1907.
1904.
1907.
Sacramento
17
10
8
2
11
2
3
5
13
1
7
2
1
4
3
ii.a*
16.52
22.71
17.60
20.46
9.54
8.28
18.60
3.34
12.58
6.56
8.12
3.44
9.63
10.60
10.13
23.24
27.20
22.57
25.67
9.80
8.46
19.12
4.86
16.84
10.20
13.15
6.37
17.12
17.10
12
Feather
41
Yuba
20
Bear
28
American
25
Stony
Cache
3
2
Puta
3
San Joaquin
45
Cosumues
34
Mokelumne
56
Calaveras
Stanislaus
62
85
Tuolumne
78
flierced
61
Flood Flow of Streams.
On the following pages is recorded the daily flow of the various
streams in the Sacramento and San Joaquin Basins for the 11 days,
March 16th-26th, also the mean daily flow for the 4-day period, March
18th-21st, at all places where gauging stations were maintained. The
figures given herein are not the final figures as they may appear in
the Annual Report of the United States Geological Survey, but they
will not differ materially from them. In all cases it is believed that
the estimates are quite conservative, and rather inclined to be too low
than too high.
Pit River. — This river drains a long, comparatively narrow, and
high mountainous area in the northeastern part of the Sacramento
Basin. In this area are several large reservoir sites. Those surveyed,
to June, 1905, have a capacity of 6 000 000 acre-ft., but Big Valley
Eeservoir, above Bieber, with a capacity of 3 196 000 acre-ft., is in all
probability the only one that could be utilized for flood control. The
precipitation in this basin above Bieber was comparatively light, and
occurred mainly as snow, so that the run-off per square mile was small.
The gauging station is about 12 miles below Bieber and about 70
miles in a direct line above the mouth of the McCloud River. The
area above this gauging station is 2 950 sq. miles. Table 5 contains
data on the flood flow at this station during the flood of 1907.
122 THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [Papers.
TABLE 5. — Flow of Pit Kivee, near Bieber.
Date, 1907.
Gauge height.
Di.scharge, in cubic feet
per second.
March 16th
6.5
12.8
15.5
16.4
15.5*
14.0*
11.5*
9.7
8.5
7.4
7.3*
2 770
" irth
17 400
'• 18th
•' 19th
25 000
27 500
'• 20th
25 000
■' 21.st
20 800
•' 32d
13 800
'• 2:M
S810
" 24th
6 110
'• 25th
4 160
" 26th
4 000
Period.
Mean daily discharge, in
cubic feet per second.
Total run-oft", in acre-feet.
February
4 180
6 940
24 600
232 000
Blarch
427 000
Blarch 18th-Slst
195 000
* Estimated.
The mean rate of flow for the 24 hours when it was greatest was
9.3 cu. ft. per sec. per sq. mile, and the mean rate for the 4 consecutive
days, March 18th-21st, was 8.3 cu. ft. per sec. per sq. mile. This small
run-off was due to light precipitation and to the slow melting of the
snow.
McGloud River. — McCloud River, the principal tributary of the
Pit River, drains a long, narrow, mountainous, timbered strip of about
676 sq. miles on the north side of the Pit River Basin, including the
southern and eastern slopes of Mount Shasta. Its low-water flow is
remarkably large, never having been less than 1 200 cu. ft. per sec. at
the gauging station in 4 years.
The gauging station is 14 miles east of Baird Spur, on the South-
ern Pacific Railroad, at Gregory Post-Office, and the drainage area
above it is 608 sq. miles. Table 6 contains data on the flow at this
station during the flood of 1907.
The mean rate of flow at this station for the 24 hours w^hen it was
greatest was 50.0 cu. ft. per sec. per sq. mile, and the mean for the
4 consecutive days, March 18th-21st, was 35.5 cu. ft. per sec. per sq.
uii'o.
Upper Sacramento River. — The gauging station on the Upper
Sacramento is in the foot-hills near Iron Canyon, 4 miles above Red
Bluff, at an elevation of about 310 ft. above sea level. The drainage
Papers.] THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS
123
area above it includes 9 300 sq. miles of mountains and foot-hills.
About 38% of this area is above the stations on Pit and McCloud
Rivers. Table 7 contains data on the flow of the river at this place
during the floods of 1907 and 1904. ,
TABLE (). — Flow of McOloud River, near Gregory.
Date, 1907.
Gauge height.
March 16th
l~th
18th
19th
'30th
'^.8
4.0
9.4
13.0
10.65
2l!-t
22d . .
23d..
24th.
25th.
26th.
.5
5.9
5.5
4.9
4.55
3.95
Discharge, in cubic feet
per second.
2 460
4 310
19 200
30 too
24 200
12 700
8 360
7 400
6 060
5 300
4 120
Period.
Mean daily discharge, in cubic
feet per second.
Total run off, in
acre-feet.
February. .
5 490
305 009
March... .
5 990
21 600
1
368 000
March 18th-21st
171 000
TABLE 7. — Flow of Upper Sacramento River,
NEAR Red Bluff.
Date. 1907.
March 16th
" 17th
" 18th
•' 19th
•' 20th
•• 21st.
■' 22d..
•' 23d.,
" 24th
^' 25th
'' 26th
Gauge
height.
10.0
31.4
36.05
28.7*
22.85
18.4
31.65
16.8
14.3
13.25
Discharge, in
cubic feet
per second.
23 600
.39 100
118 000
164 000
192 000
132 000
92 900
120 000
80 800
64 000
57 100 .
Date, 1904.
Gauge
height.
Mar
eh 7th 16.30
8th I 24.40t
9th ! 18.95
10th : 17.90
11th ; 15.80
12th I 14.70
13lh 13.30
14th 1 15.80
15th I 17.25
l'6th 18.30
Discharge, in
cubic feet
. per second.
77 200
147 180
97 300
88 940
73 700
66 220
57 400
73 700
84 050
92 040
Period.
Mean daily discharge, in
cubic feet per second.
Total run-off, in
acre-feet.
February, 19C4
46 300
73 300
45 700
55 700
152 000
2 670 000
March, 1904
February. 1907
March. 1907
March 18th-21st, 1907
4 510 000
2 540 000
3 430 000
1 200 000
* Maximum stage, 29.4 ft.; discharge. 204 000 cu. ft. per sec. at 2 p. m.
t February 16th, the stage was 38.00 ft.: maximum stage. 31. (i tt.: dischan
cu. ft. per sec. in the evening. On the 15th the stage was 17.4 ft. and on the 17th, 1
■ge, 234 OCO
2 ft.
124 THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [Papers.
The mean rate of flow at this station, for the 24 hours when it was
greatest, was 20.T cu. ft. per sec. per sq. mile, and the mean for the
4 days, March 18th-21st, was 16.3 cu. ft. per sec. per sq. mile.
Attention is directed to the fact, shown in Table 7, that, although
the flow for 4 days of the 1907 flood was greater than for any 4 con-
secutive days of 1904, the total flow for March, 1907, is only 76% of
that for March, 1904.
By comparing the discharges and drainage areas above the gauging
stations on the Pit, McCloud, and Sacramento Rivers, it is seen that,
although the drainage area above the stations on the Pit and McCloud
Rivers is 38% of that above the station on the Sacramento, the com-
bined flow at these two stations is only 21% of that of the Sacramento
during February, and 23% during March. This condition is due
largely to the slower melting of snow during these months in the
higher parts of the basin.
Feather River. — The Feather, the largest tributary of the Sacra-
mento, derives its water from melting snow in the high Sierras, the
highest point in its basin being more than 10 000 ft. above sea level.
The main river is formed by the union of three streams, the North,
Middle, and South Forks, above Oroville. Its principal tributaries
are the Yuba and Bear Rivers, which enter it below Oroville.
TABLE 8. — Flow of Feather Kiver, at Oeoville.
Period.
Mean daily discharge, in
cubic feet per second
Total nan-off, in
acre feet.
February, 1904
27 800
39 500
21500
36 000
97 300
1 600 000
March, 1904
2 430 000
February, 1907
1 190 000
March, 1907
2 210 000
March 18th-21st, 1907
770 000
* Estimated. t Maximum, about 1 a. m., 185000 cu. ft. per sec.
Papers.] the FLOOD OF MARCH, 1907, IX CALIFORNIA RIVERS
125
The ganging station is on the main stream, in the foot-hills at
Oroville. The drainage area above it is 3 640 sq. miles. Table 8 con-
tains data on the flood flow at this station during the floods of 1907
and 1904.
The mean rate of flow for the 24 hours when it was greatest was
35.6 cu. ft. per sec. per sq. mile, and the mean for the 4 days, March
18th-21st, was 26.7 cu. ft. per sec. per sq. mile.
It is seen that, although the maximum daily discharge in 1904 is
only 73% of that in 1907, the total flow for February and March is
greater in 1904 than in 1907 by 29% and 10%, respectively.
The other four largest floods in the stream on record, or even re-
called by the oldest inhabitants living along it, occurred in 1849,
!1853, 1861, and 1881. In none of these floods, however, was the water
as high at Oroville as in March, 1907. This may have been due in
part or entirely to the filling of the river channel at and below Oro-
ville with mining debris. About one-half of the Town of Oroville was
flooded for 3 days. The water was about 3 ft. deep on the floor of the
Union Hotel. The highway bridge and the Northern Electric Rail-
way bridge in Oroville were swept away, and also other bridges along
this stream.
The great range of river stage and its rapid fluctuations are shown
by Table 9, the gauge record at Big Bend, 15 miles above Oroville.
TABLE 9. — GrAUGE Eecord on Feather Eiver, at Big Bend.*
Day.
Hour.
Gauge height.
March 14th
7 a.m.
8 "
8 "
9 '■
1 P. M.
6 '•
3 A. M.
10 "
4 P. M.
1 A. M.
10 "
10 "
10 '•
5 P. M.
10 A. M.
6 9
15th
6 6
16th
6 6
17th
10 0
" 17th
13 0
171h
20 0
18th
25 0
iwth
31 0
18th
32.5
" 19th
36 0
" 19th
34 5
" 20th
28 0
" 21st
23 0
" asd
18 0
'■ 25th
10 0
Note: Low-water reading, 2 ft.
* Data furnished by Great Western Power Company, through Mr. L. J. Bevan.
Indian Creeh. — Indian Creek is a tributary of the North Fork of
the Feather River, and its water-shed is at a high altitude. The gaug-
126
THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [Papers.
ing station is about 1^ miles below the Town of Crescent Mills. The
drainage area above this station is 740 sq. miles, the larger part of it
being at an elevation of more than 5 000 ft.
TABLE Xo. IO.^Flow of Indian Ckeek, near Ceescent Mills.
Date, 1907.
Gauge height.
Discharge, in cubic feet
per second.
March 16th
17th
4.4
7.1
17.0
19.7*
17.9
14.7
10.95
9.0
7.8
7.7
7.5
905
2 570
" I8th
9 500
19th
11 500
'• 20th
10100
" 21st
7 890
^' 22d
5 365
23d..
3 900
" 24th
3 060
" 25th
2 990
" 26th
2 850
Period.
February
March
March'l8th-2ist.!!!
Mean daily discharge, in
cubic feet per second.
Total ruu-off . in acre-feet.
2 210
2 940
9 750
123 000
IM 000
77 400
* Maximum, 20.2 ft.
The mean rate of flow for the 24 hours when it was greatest was
15.5 cu. ft. per sec. per sq. mile.
It is seen that the maximum run-off per square mile during this
flood is less than one-half of that from the water-shed of the Feather
River above Oroville, due to the slower melting of the snow at high
altitudes.
Yuha River. — The Yuba is the largest tributary of the Feather
River, entering it at Marysville, 30 miles above the junction of the
Feather and Sacramento Rivers and 26 miles below Oroville. The en-
tire area drained by it is about 1 330 sq. miles, of which 1 220 sq. miles
are above the gauging station near Smartsville. The basin is com-
paratively long and narrow, the highest point having an elevation of
9 000 ft., which is not as great as that of the Feather River, the high-
est point of which is more than 10 000 ft. A large part of the basin
is more than 5 000 ft. above sea level. Table 11 contains data on the
flow of this stream at Smartsvillo during the floods of 1907 and 1904.
Papers.] THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS 127
Table 11.— Flow of Yuba River, at Smartsville.
Discharge, in
Discharge, in
cubic feet
Date, 1907.
Gauge height.
cubicj feet Date, 1904.
per second.
per second.
Mrtrnh Kith !.
14.3
24.0
6 600 Febr
56 000
uary 16th
17th
58 000
' 17th
41 000
' 18th
27.9
85 000
18th
17 880
• 19th
29.?*
100 000
19th
13 340
^ 20th
24.0
60 000
20th
9 350
' 21st
18.5
27 000
21st
9 350
• 22d
15.9
14 000
22d
59 800
• 23d
16.4
16 500
23d
27 660
■ S4th
15.0
11 OCO
24th
59 800
*■ 25th
14.5
9 900 i
25th
24 080
" 26th
14.1
8 900
Period.
Mean daily discharge, in
cubic feet per second.
Total runoff, in acre-feet.
February. 1904
March, 1904
February. 1907
March, 1907
March 18th-21st, 1907,
14 900
15 400
14 100
17 300
68 000
858 000
947 000
783 000
1060 000
537 000
* Maximum stage, 29.5 ft. about 2 p. m.
The mean rate of flow for the 24 hours when it was greatest was
82.0 cu. ft. per sec. per sq. mile. The maximum daily discharge of
this stream was 67% greater in 1907 than in 1904. The total dis-
charge for March, 1907, is larger than for March, 1904, but the total
for February and March combined is about the same for the two years.
The effect of rapid melting of snow in the middle altitudes is clearly
shown here by the large run-off per square mile.
Bear River. — The Bear is the most southern tributary of the
Feather River, entering it about 12 miles above the mouth. It drains
an area of about 290 sq. miles, of which 263 sq. miles are above the
gauging station at Van Trent, 8 miles above Wheatland. Its head-
waters do not reach back to the crest of the Sierras, and, as much of
its drainage basin is deforested, it is more torrential than the main
stream. The greatest altitude in the basin is about 5 500 ft. Table
12 contains data on its flow during the 1907 flood.
The mean rate of flow for March 19th is 106.5 cu. ft. per sec. per
sq. mile, and the mean for March 17th-20th is 75.3 cu. ft. per sec. per
sq. mile.
It will be noticed that the run-off per square mile was 106.5 cu.
ft. per sec. on March 19th, and 102.7 cu. ft. per sec. on February 2d.
128 THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [Papers.
TABLE 12. — Flow of Bear River, at Van Trent.
Date, 1907.
Gauge height.
Discharge, in cubic feet
per second.
March 16tli
4.9
13.95
12.75
17.8
13.6
9.6
8.8
13.2
9.7
9.4
8.1
900
17th
18 200
18th
15 500
19th
28 000
20th
17 400
' 21st
8 400
' 22d
6 600
' 23d
16 500
24th
8 600
25th
8 000
26th
5000
Period.
Mean daily discharge, in cubic
feet per second.
Total run-off, in
acre-feet.
February
3 460
5 570
19 800
192 000
March
;i42 000
March 17th-20th
157 000
Note : On February 2d the discharge was 27 000 cu. ft. per see.
American River. — The American River drains an area of about
2 000 sq. miles, directly south of Bear River Basin and north of
Cosumnes River Basin. It has three main forks, two of which head
at an elevation of about 9 000 ft. above sea level, while the South
Fork reaches back to an elevation of more than 9 600 ft. The gaug-
ing station is at Fair Oaks, and the drainage area above it is 1910
sq. miles, a large part of which has an altitude of more than 5 000 ft.
Table 13 contains data on the flow of this stream during the flood of
1907.
TABLE 13. — Elov^t of American River, at Fair Oaks.
Date, 1907.
Gauge height.
Discharge, in cubic
feet per second.
March Ifith
6.1
13.40
20.60
27.6*+
23.9*
21.0*
18.4*
13.5
13.25
12.80
11.50
6 800
' 17th
33 000
' 18th
63 200
' 19th
93 000
' 20t.h
' 2lst
' 22d.....
' 23d
' 24th.....
' 25th
26th
77 000
65 000
54 000
33 400
32 300
38 400
85 000
Period.
Mean daily discharge, in
cubic feet per second
Total run-off, in
acre-feet.
February
14 200
23 200
74 600
789 000
March ; . .
1 430 0(X)
March 18th-21st
594 000
* Bridges and gauges washed away. Gauge height estimated.
+ Maximum stage, 30.2 ft., about 5 a. m.
Papers.] THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS
129
The greatest mean daily discharge at this station was 48.7 cu. ft.
per sec. per sq. mile, and the greatest 4-day mean was 39.1 cu. ft. per
sec. per sq. mile.
Attention is called to the fact that the run-off per square mile for
the American River is about 50% greater than that of the Feather
River, although the percentage of each basin with an altitude exceed-
ing 5 000 ft. is about the same.
Btony, Cache, and Puta Creehs. — These three streams are the
largest tributaries of the Sacramento River from the west. They
drain the eastern slope of the Coast Range, and are torrential. Stony
Creek is the only one of the three that flows directly into the Sacra-
mento River; the other two empty into Yolo Basin. The gauging
station on Stony Creek is in the foot-hills, near Fruto, and the drain-
age area above it comprises 601 sq. miles. The station on Cache
Creek is near Yolo, and the area above it is 1 230 sq. miles. Puta
Creek station is at Winters, and the area above it is 805 sq. miles.
Table 14 contains data on the flow of these streams during the flood
of 1907.
TABLE 14. — Flow of Stony, Cache, and Puta Creeks.
Date, 1907.
Stony Creek.
Cache Creek.
Puta Creek.
Gauge.
Discharge.
Gauge. Discharge.
Gauge.
Discharge.
March 17th
t
9.45 6 100
14.25 ' 25 000
13.15 i 20 000
11.8 ! 13 450
9.8 6 810
6.80 3 950
IK .W
8 800
18th
19.45 13 500 21.60
25.90t 19 000 23.65
18.20 12 500 16.15
12.65 7 820 12.35
12.00 7 300 11 90
20.85 14 800 I 26 60*
19.30 13 400 i 15.60
16.15 10 800 14.75
12.55 1 7 750 11.40
19 800
24 700
" 19th. .
20th
10 000
21st
5 460
22d
7.75
3 350
5 000
" 23d
11.55
8.7
8.15
7.75
12 300
4 760
3 910
3 3.50
31 500
24th
9 200
25th
8 100
" 26th
4 500
Period.
Mean daily discharge, in Total run-off, in
cubic feet per second. acre-feet.
Stony Cr.
Cache Cr.
1
Puta Cr. StonyCr.
Cache Cr.
Puta Cr.
February
3 330
4 450
16 300
3 320
5 310
13 200
1 740 185 000
5 030 273 000
15 000 , 129 000
i
129 000
326 000
105 000
96 600
March
309 000
March ]8th-21st
119 000
* Maximum, 28.15 ft., about noon. t Maximum, about 26.4 ft., during night.
IBP
TSTF TM»Q1> iW mAUCM.. l!?(<^., IST CJOiEPCatXIlA iETTiESlS II'Apers.
The 5jy»JKsr flfio^j" xh^ «f Af*^ I^r sgaare amle 'was, ico- S*«m7
Qyftflg, 41.6 pu- ft. i*er sec.; f«r (Oadhe Oreek, laJ> 'Ca. ift iper sec; fw
Puia Crreei;. BS-1 cm. it iper sec The smaiH teed-jsJI l£roan Cache Basin
is ; - ' - , ■ - ^ ^ ~ ^- -~ ""■' Lake.
_ ■ ' " no i-fll^
ine SEfltann imfi Itieen esiaihiyhefl fln tSm? San Jnagrnxii Jtiver, "bacaise of
inahiEty *r ' - In liie fall of - ■' ' - "^er. a
saodat 'wai^ .^ . -^--. _ __ .^.. - ... s near J^oIlaskT, ... ... _. inils
nnrrieasi ki TTesna. ^«ehsre ifair cian^ixians dhtadn. The drainage area
flbpve tV>>s scaiiun is 1 ^€4f* sij. unolfe. Itn TTtrifciirng' say fSdjns^ jsf liie Tmn-
ttP inr Marek iStb-T" - ■ f IP <m. ft per sec par sq. ttiiTp "has
hesn Tsed. This Tr--. - -■ . tiie TaTvSS in liie hasins to xhe nartii
Hnfi simiiiu and k lefie^ed ip "he gioiff eanservatrve.
~ •? Eirer has a "rery nairo^ ami very
Itc.^ -.■.-.-.i.^. -..^- ._.__. ;^.,.:a^ easrwrard to -the surmnTt of liie
Siecras. i'Tom lie Irw f fiot-MIk "to tSk jBmcttaan nS. liie liiree hrandh^
athcmt 3C' naD^ ulicw^. aife fiaBiii k Sl ifarciacl eanjnan wiilfti 'A mamiiiiiirna
"wj ' " -' ' ' ■"'■es. A larse pere-: - :■ Trtasn r; - = '"■•^2
7 ' ' :'. in eievanioiL ei ■ -e naoire i_ - '.'0
T A"RTT ~ f — T"liOW OF 5fE(!1EEUni5TE ^IVI2L, 3CEAE CliE3i03PT5..
lajtt. ^iir.
■Eiaiure neiidit.
per sacfltnfi.
SBKdi J<n
IS fMTi
Sfl.
SOW
112-200
XTiOOO
ItSOOO
13 aw)
*!H0O
6300
%4m
reiamary
MHwdtt.
feei "Der spconcL-
2S3t)
Total nm-ofi. Sn^aert-ir-WL.
106 <sw
A-mwriif^ann aood StaaoMlaiiK ISir^eas. amd emptaes njiinip lihe Sana -Joagnin
It 1^ te
U !• i* it
t# !• U
\. ^ -
t r r «
TflE 1^ -WED
ii Jn jifi I'MrraB- ingmtr^'
snsest :a35in- Ti»^
-^irXffH. if taifec "H "figr :agjr "iitSC -&& -rrgt.'y.iriiiiri THHITf fi-*<'rijmj&
"Hft- =eE^'-' "' "'^^ ~" "-^-^SHei. ^^'- . — ' —
. -^ ^.r "Eat 3ftr.. - -— — - ^. - _ - -^ IHl
Kt si^i^srinrt tr
TA'ggry 3€. — 5^F«r ((ffl^ C>il«EM9ffiE ^^FTi^.
iCi t! Wrm^ -T ^_
atefc-SisL
.:s:aai
3«r S5K- ^er sc. TTfTfc- imt 'her j!gigihHfeL 4r-£a?- ttpstt -fi;^ S^ ji. ±i T^r
^K- 5«2r St. Trr<*. TTie Ss^tl.
rnnt tsta. m. -ttp- m-i^-«?erT2j : j : _
TttranisL ^'^tw^' *££• ^Biait. JL ^!°EznL3r y»iiiJ'''iiJ' 4;.ij»iT"iTTr TBt^ i^st -sruu—
130
THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [Papers.
The greatest daily rate of flow per square mile was, for Stony
Creek, 41.6 cu. ft. per sec; for Cache Creek, 15.5 cu. ft. per sec; for
Puta Creek, 39.1 cu. ft. per see. The small run-off from Cache Basin
is attributed to the storage and regulation effects of Clear Lake.
San Joaquin River. — Prior to the flood of March, 1907, no gaug-
ing station had been established on the San Joaquin Kiver, because of
inability to find a satisfactory section. In the fall of 1907, however, a
station was established in the foot-hills near Pollasky, about 20 miles
northeast of Fresno, where fair conditions obtain. The drainage area
above this station is 1 640 sq. miles. In making an estimate of the run-
off for March 18th-21st, a rate of 10 cu. ft. per sec. per sq. mile has
been used. This rate is based on the rates in the basins to the north
and south, and is believed to be quite conservative.
Molcehimne River. — Mokelumne Eiver has a very narrow and very
long drainage basin which extends eastward to the summit of the
Sierras. From the low foot-hills to the junction of the three branches,
about 30 miles above, its basin is a broad canyon with a minimum
width of 1.1 miles. A large percentage of the upper basin ranges from
7 000 to 9 000 ft. in elevation, and several peaks are more than 10 000
ft. high.
TABLE 15. — Floav of Mokelumne River, near Clements.
Date, If 07.
Gauge height.
Discharge, in cubic ten
per second.
March 16th
r.l5
13.60
17.00
21 00
17.9
15.9
13.0
13.3
13.0
11.6
11.8
2 000
ITth
8 600
18th
12 200
" 19th
17 000
" 20th
13 000
31st
11200
asd
8 000
2SA
SHOO
24th
8 000
25th
6 500
26th
6 400
Period.
Mean daily discharge, in cubic
feet per second.
Total run-off. in acre-feet.
February
2 920
5 320
13 350
162 000
327 000
March 18th-21st
106 000
This river drains an area of about 660 sq. miles between the
American and Stanislaus Rivers, nnrl empties into the San Joaquin
Papers.] THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS
133
cu. ft. per sec. per sq. mi*le. It is seen that the maximum run-off at
tliis station in 1904 was only 57% of that in 1907.
TABLE 18. — Flow of Stanislaus Eiver, at Knights Ferry.
Date, 1907.
Gauge height.
Discharge, in cubic feet
per second.
March 16th
8.85
14.50
17.35
35.30
19.10
15.60
14.55
14.15
13.80
14.20
13.75
3 780
17th
18th
15 580
24 100
19th
54 300
" 30th
31400
" 21st
19 300
22cl
15 740
23d
14 470
24th
13 430
25th
14 630
26th
10 420
Period.
Mean daily discharge, in
cubic feet per second.
Total run-off, in acre-feet.
February
3 440
9 880
32 250
191 000
March
608 000
March l8th-31st
256 000
TABLE 19. — Flow of Tuolumne Kiver, at LaGrange.
Date, 1907.
Gauge height.
Discharge, in cubic feet
per second.
March 16th
17th
6.55
11.30
13.50
15.75
13.00
11.50
10.50
9.80
10.65
10.65
9.30
3 430
20 300
" 18th
33 400
19th
30th
'• 21st
51 800
30 500
21 500
22d
16 700
38d
13 500
341h
17 000
25th
17 000
36th
11 500
Period.
""Zl^tltf^^'^nt Total run-Off, in acre-feet.
February
3 910 217 000
March
11 100 683 000
March 18th-21st
34 300 271 000
Tuolumne River. — Tuolumne River, which drains an area imme-
diately south of the Stanislaus River, heads in the high peaks of the
Sierras above Yosemite National Park, at an elevation of about 13 000
ft., and empties into the San Joaquin River about 10 miles west of
134 THE FLOOD OF MAKCH, 1907, IN CALIFORNIA RIVERS [Papers.
Modesto. The area above the gauging station at LaGrange is 1 500 sq.
miles. Table 19 contains data on the flow at this station during the
1907 flood.
The greatest daily rate of run-off at this station during this flood
was 34.5 cu. ft. per sec. per sq. mile, and the greatest 4-day mean rate
was 22.9 cu. ft. per sec. per sq. mile.
Merced River. — Merced River drains the area between Tuolumne
River and the Upper San Joaquin, and empties into the latter about
26 miles northwest of Merced. It heads at the summit of Mt. Lyell,
at an elevation of 13 090 ft., and drains the southern and western
slopes of this mountain, while the Tuolumne drains the northern slope.
In this basin is the famous Yosemite Valley, with its great waterfalls
and barren domes. The gauging station on this stream is at Merced
Falls, above which the drainage area is 1 090 sq. miles. Table 20 con-
tains data on the flow of this stream at the station during the flood
of 1907.
TABLE 20. — FLOW" of Merced Kiver, at Merced Falls.
Date, 1907.
Gauge height.
Discharge, in cubic feet
per second.
March 16th
" 17th
10.85
15.2
14.8
18.0
16.05
14.8
13.95
13.. 55
16.55
15.60
13.65
2 200
14 400
'• ISth
'• 19th
13 000
23 000
" 20th
" 21st
" 22(1
17 400
13 000
10 200
" 23d
8 800
" 24th
" 25th
19 200
15 800
'• 26th
9 200
Period.
February
VI arch
March 'iStli-aist '.'.'.'
Mean daily discharge, in
cubic feet per second.
1920
7 170
16 600
Total run-off, in acre-feet.
107 000
441000
132 000
The greatest daily rate of flow during this flood was 21.1 cu. ft.
per sec. per sq. mile, and the greatest 4-day mean was 15.7 cu. ft. per
sec. per sq. mile. The small run-off per square mile arises from the
fact that much of the basin has a high altitude, and that the precipi-
tation was not as heavy as in the basins to the north.
Papers.] THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS 135
Flow through Sacramento and San Joaquin Valleys.
The rate of inflow into the Sacramento and San Joaquin Valleys
from the metered mountain and foot-hill areas during this flood can
he seen from the preceding pages. For ready reference, however, these
rates of inflow at gauging stations for the 4-day period, March 18th-
21st, are given in Table 21.
TABLE 21. — Eun-Off from Sacramento and San Joaquin Basins,
IN Cubic Feet per Second, for March 18th-21st, 1907.
Place.
Drainage,
in square
miles.
Date, Ma
RCH, 1907
Mean for
March
18th-21st.
18th.
19th.
20tb.
21st.
Sacramento
Stony
Red BluflE
Fruto ...
9 300
601
3 640
1220
263
1 910
1230
805
3 907
4 250
118 000
35 000
107 900
85 000
15 500
63 200
13 500
19 800
164 000
20 000
129 6110
100 000
28 000
93 000
19 000
24 700
192 000
13 450
84 900
60 000
17 400
77 000
13 500
10 000
132 000
6 800
66 740
27 000
8 400
65 OCO
7 820
5 460
151500
16 310
Feather
Yuba
Oroville
Smarts ville
97 290
68 000
Bear
Van Trent
17 300
American
Fair Oaks
74 600
Yolo
13 200
Puta .....
Winters
15 000
Unmeterert mo
Sacramento Vf
antain and foot-hills,
illey
76 000*
25 soot
Total, Sacramento Basin
27126
554 700
Cosumnes [Michigan Bar.
Mokelumne . . . Clements.
Calaveras
Stanislaus
Tuolumne
Merced . .
San Joaquin. ..
Jenny Lind
Knights Fe^ry
LaGrange
Merced Falls
Pollasky
Unmetered mountain anJ foot-hills,
San Joaquin Valley ,
Total, San Joaquin Basin 16 372
524
7 600
82 600
9 300
3 900
642
12 200
17 000
13 000
11 200
395
3 800
26 100
3 800
3 300
935
24 100
54.300
31 400
19 300
1 500
33 400
51800
30 500
21 500
1 0'.10
13 000
23 000
17 4"0
13 000
1 640
5 656
5 890
16 372
13 3,50
13 3.50
9 250
32 250
34 300
16 600
16 40011
67 900+
23 560§
226 960
* Run-off per square mile assumed as 50% of precipitation for period, March 17th-20th,
or 20 cu. ft. per sec.
+ Run-off per square mile assumed as 50% of precipitation for perifid, March 17th-20th,
or 12 cu. ft. per sec.
i Run-off per square mile assumed as 40% of rainfall for period, March 17th-20th. or
6 cu. ft. per sec.
§ Run-off per square mile assumed as 40% of rainfall for period, March 17th-20th, or
4 cu. ft. per sec.
I' Run-off per square mile assumed as 10 cu. ft. per sec.
From Table 21 it is seen that the mean rate of run-off from the
metered area of the Sacramento Basin (83% of all mountains and
foot-hills) for the 4-day period, March 18th-21st, was about 453 000
cu. ft. per sec. The estimated run-off for this period was 76 000 cu.
ft. per sec. from the unmetered mountains and foot-hills, and 25 500
136 THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [Papers.
cu. ft. per sec. from Sacramento Valley, making a mean rate of run-
oif from the Sacramento Basin of about 555 000 cu. ft. per sec. for 4
consecutive days.
It is not possible to trace the movement of this v^ater through the
valley, on account of overflow into flood basins and breaks in the levee
system. The levees failed at many places on both sides of the Sacra-
mento Eiver, and also on some of its tributaries, and it is impossible
to compute the flow through any of these breaks. Such an estimate,
if correctly made, would have practically no value, as it would give
little idea of the distribution of flow through the valley during any
other flood when failure of levees occurred at other places.
While an estimate of the volume passing specified places in the
valley at a given time cannot be made, the points where large volumes
left the channel and returned to it again or crossed it can be indi-
cated, as well as the time of failure of important levees. On the
evening of March 20th the water was overtopping the levees for almost
the entire distance between Princeton and Jacinto, and also above and
below Colusa. On March 21st, eleven breaks in the levees occurred
between Colusa and Grimes, and during that night several breaks
occurred in the levees on the east side of Sacramento River between
Clarksburg and Courtland, allowing water from the Sacramento to
pass into Mokelumne River and thence into the San Joaquin. On
March 22d several other breaks occurred in Colusa County, and also
in the Island District, where large areas of reclaimed land were sub-
merged. On March 23d the levees of Ryer, Tyler, Brannan, Andrus,
and Bouldin Islands and the Lisbon District failed, flooding 65 000
acres of land. Besides the failures already mentioned, there were
numerous others of more or less seriousness in different places in the
Sacramento Valley.
At Knights Landing, on March 21st, the Sacramento was 1 ft.
higher than recorded at any previous time. Below this point, a large
part of the water from the Feather River was flowing across the Sacra-
mento Channel into Yolo Basin. Through the Kripp crevasse of
February 8th, opposite the City of Sacramento, a large part of the
waters of the Sacramento and American Rivers also passed into Yolo
Basin, and the water level of this basin was several feet higher than
ever known before. On February 24th the Sacramento at Rio Vista
reached its greatest height during the flood, being 3 ft. higher than
Papers.] THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS 137
indicated by previous records. The failure of the levees of Brannan,
Twitchell, and Andrus Islands, near the mouth of Cache Slough, per-
mitted a part of the water of Yolo Basin to flow across the Sacramento
Channel into the San Joaquin River, submerging large areas in the
San Joaquin Delta. In all, it is estimated that about 300 000 acres
of reclaimed land were submerged during this flood. Below the City
of Sacramento, the only reclaimed districts having levees that with-
stood the high waters are : Reclamation District No. 744 ; Merritt
Island, Grand Island, and Randall Island Reclamation Districts;
Geo. W. Locke, private reclamation; Reclamation District No. 545;
Sutter and Sherman Islands; and the northern portion of Union
Island.
Referring again to Table 21, it is seen that, in all the streams of
the San Joaquin Basin, the greatest rate of flow occurred on March
19th. On this date the mean rate of run-ofl from the metered area
(41% of all mountains and foot-hills) was about 205 000 cu. ft. per
sec. The rate from the unmetered area must have been at least
84 000 cu. ft. per sec. from mountains and foot-hills and 24 000 cu. ft.
per sec. from the valley, making a maximum run-off of about 313 000
cu. ft. per sec. from the San Joaquin Basin. The mean rate for 4
days, March 18th-21st, was about 227 0)0 cu. ft. per sec. It is im-
possible to indicate the volume of flow at different points in this valley
owing to the failure of levees on both the San Joaquin and Sacra-
mento Rivers, and the passage of a large volume from the latter into
the former, producing back-water and retardation nf flow.
It is also seen from Table 21 that the mean flow from the mountains
and foot-hills of the Sacramento and San Joaquin Basins combined,
for the 4 days, March 18th-21st, was about 732 000 cu. ft. per sec. It
is seen, too, that the mean rate of discharge into Suisun Bay for
these 4 days, if storage in the valleys had not been permitted, would
have been about 782 000 cu. ft. per sec, a volume for these 4 days of
G 200 000 acre-ft., or 9 690 mile-ft., enough to cover both basins to
a depth of 2.56 in., if spread over them evenly.
Table 22 shows the run-off, expressed as depth, in inches, over the
drainage basin, together with the precipitation for the March flood.
Of course, there is the very regrettable condition of too few and poorly
placed precipitation stations, but it is believed that the records here
given are quite representative for the different basins. This table
138 THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [Papers.
gives some idea of the effects of altitude and of melting snow in the
various drainage areas.
TABLE 22. — KuN-OFF, as Depth, in Inches.
Place of gauging.
1
oi
cS •
01 a
□
1
o
P
■0.9
Run-off per Square Mile, March, 1907.
o
P a
.S|
Mean for March 18th-21st.
stream.
a
il
tj_i o
o ®
3
u
8.3
35.5
16.3
26.7
13.2
55.7
75.3
39.1
27.1
9.3
18.6
25.5
20.8
23.4
34.5
22.9
15.7
10.0
.s •
p'
a<p
Pit
Bieber
(Gregory
Red Bluff
Oroville
Crescent Mills. .
Smartsville
Van Treut
Fair Oaks
Fruto
Yolo
Winters
Michigan Bar . .
Clements
Jenny Lind
Knights H erry. .
La(irange
Merced Falls...
Pollasky
2 950
(iOS
9 300
3 640
740
1 220
263
1910
601
1 230
805
524
642
395
935
1500
1 090
1640
9 900
14 400
14 400
10 000
7 000
9 000
5 500
9 600
"Vmo
10 000
6 000
11500
13 000
13 000
13 000
9.3
50.0
20.7
35.6
15.5
82.0
106.5
48.7
41.6
15.5
39.1
62.2
26.5
66.2
58.1
34.5
21.1
(Est.)
1.23
5.28
2.43
3.97
1.96
8.29
11.30
5.81
4.03
1.38
2.77
3.80
3.08
3.48
5.14
3.40
2.34
1.49
McCloud
Sacramento
Feather
6.56
10.40
10.00
10.33
8.13
8.63
5.27
5.00
5.10
7.50
6.42
5.06
6.26
6.65
5.92
5.00
37
29
Indian Cr
Yuba
20
80
Bear
American
Stony Cr
139
67
76
Cache Cr
Puta Cr
28
54
Cosumnes
Mokelumna . ...
Calaveras
Stanislaus
Tuolumne
Merced
51
48
69
82
51
40
San Joaquin
30
Rate of Flow in Sacramento Valley.
It will he instructive to compute the probable rate of flow of the
Sacramento River during this flood at the four places where it re-
ceives large volumes of water from tributaries, namely, just below the
mouths of Stony Creek, Feather and American Rivers and Cache
Slough, taking into account the time required for the water to pass
from the gauging stations to the Sacramento and the time to pass be-
tween the above-mentioned places. No great degree of refinement
will be attempted, as the data will not warrant it.
As a flood wave travels down a channel there is a gradual diminu-
tion of its height, due to the filling of the channel and the flattening
of the wave. Such diminution would have been small for this flood,
and is neglected in the computations, for the following reasons :
(1). — The flood wave was a long one, the water at some of the
stations continuing to rise for 4 days;
Papers.] THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS 139
(2). — The streams had reached a comparatively high stage on
March 17th, and consequently their channels were from
more than half to two-thirds full at the date when the
computations begin;
(3). — The rates of flow computed at gauging stations are 24-
hour means, not maxima for a few hours.
It can be shown that the speed of a flood wave, M, in a stream
channel, is given by the equation.
d Q
dh
M W, in which d Q is the
increment of discharge corresponding to the increment of stage, d h,
and W is the channel width. The value of M has been computed at
each gauging station for intervals of 1 ft. in gauge height during the
flood stages, and a mean value obtained for the distance, in ho.urs,
from the gauging station to places along the Sacramento River. These
results are given in Table 23 :
TABLE 23. — Data on Kate of Progress of Flood Wave, in
Streams, if Water Were Confined in Channels.
Place to place.
Gauging Station, Sacramento River to mouth of Stony Creek...
Gauging Station, Stony Creeli to mouth of Stony Creek ,
Gauging Station, Featlier River to mouth of Feather River
Gauging Station. Yuba River to mouth of Feather River
Gaugmg Station, Bear River to mouth of Feather River
Mouth of Stony Creek to mouth of Feather River
Gauging Station, American River to mouth of American River.
Mouth of Feather River to mouth of American River
Mouth of American River to mouth of Cache Slough
Gauging Station, Cache Creek to mouth of Cache Slough
Gauging Station, Puta Creek to mouth of Cache Slough
^
a> b
>■ a>
^
cS O.
5
1-2
9
40
35
6
60
7
50
8
15
5
100
7
15
5
ao
7
46
7
45
4
45
4
Note: The rate of travel for flood waves, as given above, is thf mean of the computed
rates on each of the days, March 17th-31st, reduced, in most instances, by a considerable
percentage.
A study of the daily rate of discharge of the streams in the Sacra-
mento Basin, for March 18th-21st, Table 21, shows that the discharge
at places along the Sacramento River was undou' tr'dly at a maximum
when the crest of the wave from the Feather River reached them.
This wave crested at Oroville about 1 A. M., March 19th. As Oroville
is about 9 hours above the mouth of Feather River, the crest would
reach the Sacramento River at about 10 a. m., March 19th, with a
discharge of about 258 000 en. ft. per sec, including the Yuba and
140 THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [Papers.
Bear Elvers. This amount, combined with the flow in the Sacramento
at that time, would give the maximum discharge just below the mouth
of the Feather Elver. The flow in the Sacramento at this time, how-
ever, was the flow at the gauging station above, about 19 hours before,
combined with the flow at the gauging station on Stony Creek,
about 20 hours before, or the flow of the two at, say, 2 p. M., March
18th. This flow was 143 000 cu. ft. per sec, which, added to the
258 000 cu. ft. per sec. from the Feather Elver, would give a discharge
of 401000 cu. ft. per sec. in the Sacramento. This volume would
reach the mouth of American Elver 3 hours later, and be augmented
by 93 000 cu. ft. per sec. passing the gauging station 3 hours before,
sc that the maximum discharge in the Sacramento below the mouth
of the American Elver would be about 494 000 cu. ft. per sec, and
would occur at about 1 P. M., March 19th. This volume would reach
the mouth of Cache Slough at about 8 p. m., March 19th, to be in-
creased by the flow of the Cache and Puta Creeks at the gauging
stations 11 hours before, which amounted to about 44 000 cu. ft. per
sec. Below the mouth of Cache Slough, therefore, the discharge would
have been about 538 000 cu. ft. per sec. It is to be noted that the
maximum flow in the Sacramento below the mouth of Stony Creek
was about 205 000 cu. ft. per sec, and did not occur until some time
on March 20th.
The figures just given do not include the unmetered flow of 76 000
cu. ft. per sec from the mountains and hills below the metered basins,
nor the 25 500 cu. ft. per sec from the valley. It is evident that, un-
less stored in the flood basins, it must have appeared in the Sacramento
below Cache Slough. It is impossible to compute the increase in dis-
charge at the diflerent places on the Sacramento Elver due to these
two rates of inflow, because it is not known at what points all these
waters were delivered; but it is quite clear that there must have been
a very decided increase above the mouth of Stony Creek from each
side of the river. On the east side there are 1 600 sq. miles of moun-
tains and foot-hills lying between the Feather and Upper Sacramento
Basins, which are drained by numerous creeks, the most important
of which are Mill and Deer Creeks, the headwaters of which come from
Lassen Peak, more than 10 000 ft. in altitude. Several of the stations
reporting the greatest precipitation in March, 1907, are in this area or
very near it. Taking into consideration its position between two
Papers.] THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS
141
basins in which the rate of i^in-ofE is known, together with its heavy
precipitation and generally lower altitude, it is believed that the mean
rate of run-off may be safely placed at 25 cu. ft. per sec. per sq. mile
for the period, March 18th-21st. This means 40 000 cu. ft. per sec.
from this side. On the west, above the Stony Creek Basin, are 1 080
sq. miles of mountains and foot-hills, for which it is safe to put the
run-off at 15 cu. ft. per sec. per sq. mile, or a mean of 16 000 cu. ft.
per sec. for jVIarch 18th-21st. This would mean an increase in the
discharge below Stony Creek of about 56 000 cu. ft. per sec.
A considerable area of mountains and foot-hills between the Feather
and Bear Basins must have contributed a large volume to the Sacra-
mento through the Feather River, so that, all told, the maximum dis-
charge below the mouth of the Feather River was probably at least
65 000 cu. ft. per sec. greater than that computed above. As the rates
of run-off for the unmetered area of mountains and valley are 4-day
means, the maximum discharge below Cache Slough must have been
about 640 000 cu. ft. per sec. This maximum, however, is only 15%
greater than the 4-day mean flow of 555 000 cu. ft. per sec. for March
18th-21st.
It will be noticed that the maximum discharge just below the
mouth of Cache Slough would probably occur at 8 p. M., March 19th,
if the water were confined in channels. But the maximum stage at
Rio Vista, a few miles below the mouth of this slough, actually oc-
curred at 11 p. M., March 23d. Overflow and storage in the flood
basins, therefore, delayed the arrival of the flood crest at Cache Slough
about 4 days.
Table 24 is a comparison of maximum rates of flow of the Sacra-
mento River during this flood with those assumed by the 1904 Engi-
neering Commission, provided that the total run-off is confined be-
tween the levees and not allowed to collect in the flood basins.
TABLE 24.
Place.
Maximum rate assumed by
1904 Engineering Commission.
Cubic feet per second.
Maximum rate computed
from March, 1907, flood.
Cubic feet per second.
Below mouth, Stony Creek
" " Feather River . .
" " American River.
" " Cache Slough...
180 000
190 000
230 000
250 000
261 000
466 000
559 000
640 000
142 THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [Papers.
These computed rates are from 45 to 156% larger than the as-
sumed rates.
Profile of Flood Wave in Sacramento Kiver.
Fig. 2 is a profile of the flood wave iu Sacramento River during
March, 1907. This profile merely shows the greatest elevation of the
flood plane above mean sea level at different points along the course
of the river. In other words, the maximum height attained by the
flood at various points is platted with reference to the distance from
the mouth of the river and the elevation above mean sea level. An in-
spection of this profile shows that the mean gradient of the flood plane,
In feet per mile, between observed points, decreases quite rapidly from
Red Bluff toward the mouth of the river, actually changing sign below
Walnut Grove. This gradient varies from — 2.41 between Red Bluff
and Munroeville, near the mouth of Stony Creek, to + 0.01 below
Walnut Grove. Such a reversal of slope would seem to indicate a
constricted condition of the channel near the mouth of the river.
A profile of the flood wave of 1905, made under the direction of the
Commissioner of Public Works of California, is also shown on Fig.
2 for the purpose of comparison. This profile may be considered as
typical of the usual flood wave in the spring of each year.
Losses Due to the Flood of March, 1907.
The losses resulting from this flood consisted mainly in the de-
struction of the crops then growing on about 300 000 acres of land
completely inundated, together with the damage done to a portion of
the prospective yield for the season of 1907. In addition to this, many
miles of costly levees had to be rebuilt and many miles more ex-
tensively repaired on account of overtopping and wind action. The
railroads suffered heavily, in bridges and culverts washed out, in injury
to miles of roadbed, and in loss of traffic. The line from Marysville
to Knights Landing was closed from March 19th to May 13th. Among
the larger bridges swept away or badly damaged were the highway and
the Northern Electric Railway bridges across the Feather River at
Oroville, the highway bridge across the American River at Fair Oaks,
the highway bridge on the Mokelumne River near Clements, and the
bridge on the Cosumnes River at Bridge House. Three costly dredges
for mining gold-bearing gravel in the Feather River near Oroville were
Papers.] XHE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS
143
'^ 5
9 <
i
Ked
/
Bluff
h
/
/
/^
^^
.
A
^,v
/
o
/ /
Mu
nroev
ille
o
/
/
///
,J
1:^
o
/
b
c
B
»
rv
/ /
if
1
Colu
sa
1 1
o
/
/
1
b
/
; /
£.
Ik
1 !t
1
0
■n
-D
o
1
1
Knig
Its-Lj
ndinj
? ^6
^ 0 -n
> >
'IS
1
1
E 5 r-"
/
/
t
^0 p3H -n
1
1
/
Ig
^^ OS 1 T1
/
/
/
/
Sacrame
i 1
uto
c
tt-
' /« Freeport
^
r- r
a
41 Richland
iS Courtland
I
Tl
<
m
+
b
Walnut Grove
B
Isleton
Mouth Cache SI
Kio Vista
mgh
(JoUinsville
Elevat
ions in
feet a
jove m
9an se
I level
<
z
5
S 1
S c
:i c
\
;
1
1 ?
I Z
^ 1
144 THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [Papers.
destroyed. Many towns and villages were partially inundated, subject-
ing the inhabitants to serious inconvenience at the time and to heavy
expense in repairs later. The greater part of Stockton was flooded for
nearly a week, because of the failure of the levees along Mormon
Slough and Jackson Creek. About half of Oroville was flooded for
three days, and one hundred and twenty-five families were driven from
their homes. The restraining dam on the Yuba River, 14 miles above
the mouth, known as Barrier No. 1,* was destroyed on the night of
March 18th. This dam was built to hold back the mining debris in
the channel above. With its destruction, practically all the debris
restrained by it (probably amounting to more than 1000 000 cu. yd.),
■was transferred to the channel below. It is estimated that the total
damage resulting from this flood exceeded $5 000 000.
Effect of Mining Debris on Floods.
From 1849 to 1880 enormous quantities of debris — sand, gravel,
and cobbles, the tailings from hydraulic mining — were deposited in
the upper course of several of the streams on the eastern slope of the
Sacramento Basin. The volume of this debris in the Yuba River
alone has been variously estimated at from Yl 000 000 to 700 000 000
cu. yd. At the mouth of the river, near Marysville, it has a depth of
7i ft.; at Dugnens Point, 11 miles above the mouth, it has a depth
of 26 ft., and at The Narrows, 18 miles above the mouth, it has a
depth of 84 ft. The gradual elevation of the flood plane at Marysville,
due to the accumulation of debris in the channel at this place, is shown
by the maximum gauge readings at Marysville (Table 26). The zero
of the gauge is the elevation of low water in 1872.
TABLE 26. — Maximum Gauge Readings at Marysville.
Date.
Gauge height, t
January
11, lWi3
11 ft. 6 in.
March
6, 1869
15 " 11 ••
January
19. 1875
15 '• 2 '■
April
23, 1880
I') '■ 3 "
February
34, 1881
18 " 2 "
December
23, 1884
17 " 1 '•
January
18, 1898
18 '■ 5 "
March
25, 1899
18 " 5 •'
February
31, 1901
19 '• 0 '■
February
25, 1904
20 •' 0 '•
January
19, 1906
21 " S •'
February
3, 1907
21 " 3 "
March
19, 1907
33 •' 4 "
*The failure of this structure is described in Engineering News, Aug. 8th, 1907,
t Data furnished by W. T. Ellis, Levee Commissioner.
Papers.] THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS 145
The low-water reading on this gauge, in the summer of 1906, was
9.0 ft. The flood of 1907, however, changed the low-water channel
from the right to the left side of the river, so that in Augiist the
elevation of the water surface could not be read at all, the debris
around the gauge being 3 ft. higher than the water.
The failure of Barrier Dam No. 1, on the Yuba River 14 miles
above the mouth, liberated about 1 300 000 cu. yd. of debris which
was deposited in the bed of the stream at varying distances below the
dam, depending upon the size of the material. The deposition of this
enormous volume of material in the stream bed, and the gradual ele-
vation of the flood plane due to it, require frequent raising and widen-
ing of the levees along the river. Such a condition is fraught with
growing peril to the valley land and to all interests adjoining the river.
Effect of Storage Reservoirs on Floods.
Any rational system of reclamation for the overflow lands in the
Sacramento and San Joaquin Valleys must make provision for passing
the peak of the floods rapidly to Suisun Bay. The volume of flood
water to be passed in Sacramento Valley, as determined by actual
gaugings of the flood of March, 1907, largely exceeds all estimates
previously used as a basis for the computation of proper channel
capacity to carry safely the flood waters of the Sacramento River.
Indeed, it may be that the task of rectification and enlargement of
channel necessary to pass such floods as that of March, 1907, is so
great as to make it economically impossible. In such event, some
auxiliary system of flood control would have to be devised. Probably
no more effective and easily executed auxiliary system could be found
than that of large, regulating storage reservoirs in the mountains.
Such reservoirs could be utilized to store water during floods, thereby
reducing the peak of the flood in the valley sufficiently to allow the
main channel to carry it safely to Suisun Bay.
The United States Reclamation Service has located the principal
reservoir sites in the Sacramento Basin, and has made surveys to
determine the capacity and probable cost of most of them. Of the
reservoirs surveyed to date, four are in Stony Creek Basin, with a
total capacity of 124 100 acre-ft. ; two are in Cache Creek Basin, with
a total capacity of 176 500 acre-ft. ; two are in Puta Creek Basin, with
a total capacity of 318 000 acre-ft. ; seven are in Feather River Basin,
146
THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [Papers.
with a total capacity of 775 600 acre-ft. ; four are in Pit River Basin,
one of which has a capacity of 3 196 000 acre-ft. ; and one is on the
Upper Sacramento River at Iron Canyon, with a capacity of 226 900
acre-ft. In the San Joaquin Basin no reservoir sites have been located
and surveyed yet, although it is probable that the area contains some
good ones.
Table 27. — Rkservoir Data.
Capacity,
in
acre-feet.
Drain-
age, in
square
miles.
Volume Available for Storage,
in Acre-Feet.*
Name of Reservoir.
5
5
Stony Creek Basin.
East Park
Stony Ford
26 000
40 000
14 400
43 700
114
no
58
323
9 390
9 060
4 770
26 600
10 600
2 680
13 500
7 520
7 250
3 820
21300
5 060
4 880
2 570
14 300
2 560
2 470
1300
7 250
24 530
23 660
12 460
Mill Site
69 450
Cache Creek Basin.
100 000
76 500
486
123
631
14 900
3 770
24 600
9 790
2 480
12 500
3 460
14 800
998
2 040
31700
23 500
1 350
8 000
47 000
55 800
6 120
1550
7 820
41 410
Little Indian
Below reservoirs and above
10 460
52 820
PuTA Creek Basin.
Guenoc
188 000
130 000
148
603
54
7 210
29 400
1980
8 990
36 600
2 460
1990
8 110
546
31830
88 910
Below reservoirs and above
5 984
Feather River Basin.
61800
12 600
■ 500 000
46 270
86 100
68 800
44
682
506
29
172
1010
1 300
2.580
40 000
■29 700
1 700
10100
59 300
70 400
49 (iOO
3 100
48100
35 600
2 040
12 100
71 200
84 500
1 600
24 800
18 400
1 050
6 260
36 700
436 0
9 320
144 600
Big Meadow
107 300
Buck's Valley and Spanish
Ranch
6140
36 460
214 200
Below reservoirs and above
254 300
3 196 000
Pit River Basin.
Big Valley
3 950
54 500
49 600
41200
220 800
194 900
Sacramento River.
226 900
6 350
184 400
270 500
331400
1007100
* The daily run-ofif per square mile is assumed to be constant over the basin abov e the
gauging station.
In Table 27 are shown the reservoir sites in the Sacramento Basin
which could be used for flood control, together with the drainage area
Papers.] THE FLOOD OF MARCH, 1907, IN CALIFOKNIA RIVERS 147
tributary to each and its capacity in acre-feet. Assuming the run-oS
per square mile to be constant in any particular basin, the quantity of
water available for storage at each reservoir is given for each of the
days, March 18th-21st, and also the total for the 4 days. It will be
noted that some of these reservoirs would be only partially filled by
the flood flow of March 18th-21st, while others would store but a small
percentage of the run-off for this period.
A study of Table 27 will show that the four reservoirs in Stony
Creek Basin would have stored the run-off from 481 sq. miles, or 80%
of the area above the gauging station, and would have reduced the
maximum daily flow from 25 000 to 5 000 cu. ft. per sec. The two
reservoirs in Cache Creek Basin would have stored the flow from 609
sq. miles, or 50% of the area above the gauging station, and would
have reduced the maximum daily flow from 19 000 to 9 500 cu. ft. per
sec. The two reservoirs in Pvita Creek Basin would have stored the
flow from 751 sq. miles, or 93% of the area above the gauging station,
and would have rediiced the maximum daily flow from 24 700 to 1 700
cu. ft. per sec.
The seven reservoirs in Feather River Basin would have stored the
flow from about 1 134 sq. miles, or 31% of the area above the gauging
station at Oroville, leaving 2 506 sq. miles uncontrolled. Of this un-
controlled area, 623 sq. miles are above Mohawk Valley Reservoir,
683 sq. miles are above Indian Valley Reservoir, and 1 200 sq. miles
are below the reservoirs and above the gauging station. This storage
would have reduced the daily flow at Oroville as follows :
From 107 900 to 74 300 cu. ft. per sec. on March 18th ; from 129 600
to 89 200 cu. ft. per sec. on March 19th; from 84 900 to 58 500 cu. ft.
per sec. on March 20th ; and from 66 740 to 45 900 cu. ft. per sec. on
March 21st. Big Valley Reservoir, on Pit River, would have stored the
entire flow at that place and reduced the daily flow of the Sacramento
River at Red Bluff about 25 000 cu. ft. per sec. The storage at Iron
Canyon, together with that on Pit River, would have reduced the
greatest daily flow of the Sacramento River at Red Bluff from 192 000
to 106 000 cu. ft. per sec.
The combined effect of all these reservoirs in operation at the same
time would have been to reduce the maximum flow in the Sacramento
River by about 86 000 cu. ft. per sec. above the mouth of Stony Creek,
106 000 cu. ft. per sec. above the mouth of the Feather River, and
179 000 cu. ft. per sec. below the mouth of Cache Slough.
148 THE FLOOD OF MARCH, 1907, IN CALIFORNIA RIVERS [P-ipeiS-
It would seem that the ultimate solution of the flood problem in
the lower portions of the Sacramento Valley is closely interwoven
with the reclamation of the higher portions by irrigation. Keservoirs
which would impound flood waters and reduce the peak of floods, so
ap to save the lowlands from overflow in the early spring, would serve
later as storage reservoirs from which to draw for irrigation purposes.
The flood problem in this valley is indeed a very serious one, and
merits the most careful and thoughtful consideration.
Vol. XXXIV. FEBRUARY, 1908. No. 2.
AMERICAN SOCIETY OF CIVIL ENGINEEES.
INSTITUTED 1852.
PAPERS AND DISCUSSIONS.
This Society is not responsible, as a body, for the facts and opinions advanced
in any of its publications.
THE REINFOKCED CONCRETE WORK OF THE
McGRAW BUILDING.
Discussion.*
By Messrs. T. L. Condron and F. F. Sinks, E. W. Stern, L. J.
Mensch, and p. E. Stevens.
T. L. Condron and F. F. Sinks, Members, Am. Soc. C. E. (by Messrs. Con-
letter). — No good reason can be offered for not exercising the same
common sense in designing reinforced concrete strilctures as that ex-
pected and demanded in designing steel or timber structures. Too
much is heard regarding "systems" of reinforced concrete, and too
little regarding the simple application of the well-known hiws relating
to the strength of materials and the distribution of stresses in such
structures. It is not many years ago that iron bridges were btiilt ac-
cording to one or another special, and generally patented, type. To-day
the "patented bridges" are limited to draw bridges, which, after all,
are machines as well as structures. It is doubtless true that, in a
large measure, the present wide use of reinforced concrete is due to
the energetic promotion of various so-called "systems," together with
the equally energetic promotion of concrete construction by makers
of various forms of reinforcing materials. While, in some cases,
capable and conscientious engineers have done splendid work in de-
veloping new and better designs for reinforced concrete as a substi-
tute for designs of steel or masonry structures, in other cases, less
capable, and in some instances ignorant, men have produced "sys-
tems" which would be ridiculous if they were not dangerous.
♦Continued from January, 1908, Proceedings.
150 DISCUSSION ON KEINFORCED CONCEETE BUILDING [Papers.
Messrs. Con- In designing reinforced concrete, the writers have endeavored to
' follow the same methods of analysis of stresses and proportioning of
parts as they use in designing steel structures. They have studied
carefully all the experimental and research work done by the leading
technical schools and universities, and believe that more can be gained
by such study than by simply developing any refined theoretical
analysis of the strength of .concrete reinforced with steel.
The writers present herewith illustrations of what they believe to
be rational designs of reinforced concrete construction. Care has been
taken to have these designs free from every unnecessary complica-
tion, the whole aim being to gain great strength and everlasting
durability with the most simple construction possible.
The author's description of the McGraw Building is of especial
interest, as there are several features in its design which are similar
to those used by the writers; therefore, they present the following
description of one building, and some notes regarding two others,
designed by them.
The Manufacturers' Furniture Exchange Building, in Chicago,
the reinforced concrete features of which were designed by the writers,
as Consulting Engineers for the Architect, Mr. William Earnest
Walker, was designed in the spring of 1906 and completed near the
close of that year. In the McGraw Building, as well as in the build-
ings designed by the writers, the columns have been reinforced with
latticed steel angles. As far as the writers are aware, the first rein-
forced concrete building in which columns of this form were used
was the Watson Building, in Chicago, built in 1905, for which Messrs.
Huehl and Schmidt were the Architects. The writers' original recom-
mendation for the columns of this building was that the angles be
latticed, but they were actually built with horizontal tie-plates, as
shown by Fig. 1, Plate XXIV. At the time this photograph was taken
the view. Fig. 2, Plate XXIV, was also taken on the first floor, where
concreting was going on, the forms for the floors above being siipported
so that they did not interfere with the placing of concrete on this
floor.
The general plans for the Manufacturers' Furniture Exchange
Building were completed in June, 1906, and the contracts were let
about July 1st. The building is near the business center of Chicago,
and has a frontage of 70 ft. on Wabash Avenue, running back 170 ft.
on Fourteenth Street to an alley. The general appearance of the
building is shown by Fig. 1, Plate XXV. It is an eight-story and base-
ment building, designed for furniture show rooms, warehouse pur-
poses, or light manufacturing. The floors are designed to carry live
loads of 160 lb. per sq. ft. on the lower floors, and 100 lb. per sq. ft. on
the upper floors. Fig. 2 is a plan and Fig. 3 a cross-section of the
building, showing the general arrangement of the columns and beams.
PLATE XXIV.
PAPERS, AM. SOC. C. E.
FEBRUARY, 1908.
CONDRON AND SINKS ON
REINFORCED CONCRETE BUILDING.
Fig. 1.— Second and Third Story (_".ii,i mx Keinforcin j, Watson Building.
Fig. 2.— Concreting on First Floor, Watson Building.
Papers.] DISCUSSION ON REINFORCED CONCRETE BUILDING
151
On the first floor a bulkhead is carried around on two sides, sup- Messrs. Con-
porting platforms for the show windows and permitting half windows
for lighting the basement. The second to eighth floors, inclusive, are
exactly alike. The roof is of reinforced concrete, and has two rows
of saw-tooth skylights.
[^ 70 iX-
E3
u
levator MA/ ^
Shaft-Ty\
[] o ® e&
=©=©=
0
T
PLAN OF 2ND TO 8TH FLOOR
Fig. 2.
4 Concrete TaU
Fig. 3.
In designing the columns, the ratio of the moduli of elasticity of
steel and concrete was assumed as 15 to 1. The columns were not
considered as hooped concrete, only 500 lb. per sq. in. being allowed
for the working stress on the concrete and 7 500 lb. per sq. in. on the
steel. Only one change was made in the size of the concrete columns.
From the basement to the third story the columns were 24 in. square,
and above that they were 20 in. square. The corners of the columns
were rounded to a radius of 4 in., except in the basement.
Fig. 4 shows the typical reinforcement of the columns, girders, and
slabs. Temporary cross-angles were bolted to the steel column rein-
153
DISCUSSION ON REINFORCED CONCRETE BUILDING [Papers.
Messrs. Con-
dron and Sinks.
forcement to support the column forms, and, in turn, the floor forms
above. After the concrete for one floor was finished, the weight of
the form work of the floor above was supported by shores in the usual
manner, resting directly on the finished concrete floor. The temporary
angles were then removed from the columns, and the column boxing
was closed, preparatory to casting the concrete in the column section
above the finished floor. This is all shown quite clearly in Figs. 1
and 2, Plate XXVI.
-I'OK-^'
% Finish
Fig. 1, Plate XXVI, is a photograph taken at the beginning of the
concreting work on the first floor (October 10th, 1906), and when taken,
the forms were completed for the first floor, the reinforcement of this
floor was in place, the column reinforcement, extending from the
PLATE XXV.
PAPERS, AM. SOC. C. E.
FEBRUARY, 1908.
CONDRON AND SINKS ON
REINFORCED CONCRETE BUILDING.
./f / /i ■ A^
Papers.] DISCUSSION ON REINFORCED CONCRETE BUILDING 153
footings to the level of the second floor, was also in place, and the ^®^,^''^: ^P^-
basement columns were cast. The character of the column reinforce- '
ment is shown very clearly in this photograph. The points where the
lacing of the columns is omitted near the top are the openings left
for the reinforcement for the second-floor beams to pass through.
In Fig. 2, Plate XXVI, the temporary angles may be seen near the
bottom of the column in the foreground. This photograph was taken
on November 6th, and shows the concreting in progress on the second
floor. After the concrete work on the first floor was finished, no more
concreting was done until after the forms for the second and third
floors were both completed. The carpenters then worked on the third
floor, building the forms for the fourth floor. At this stage of the
work the reinforcing material for the second floor was placed, and
the concreting of this floor proceeded. The photograph. Fig. 1, Plate
XXVII, was taken at the same time as Fig. 2, Plate XXVI, from which
it will be seen that the exterior walls had been run up practically to the
level of the fourth floor, and the carpenters are seen working on the
fourth-floor forms, and, as stated previously, concrete was being placed
on the second floor. From this time forward, both the concrete gang
and the carpenters were kept constantly at work, the carpenters being
two stories ahead of the concrete gang. In order to prevent freezing,
the window openings were closed, and coke fires were kept burning in
salamanders in the story directly under the floor on which concrete
was being placed. As a consequence, the concreting went on at a
temperature that was considerably above the freezing point, even in
the coldest weather. The cement finish was put on the concrete floors
as soon as the first concrete had taken its initial set. Owing to the
prevalence of rainy weather during this construction, considerable
trouble was caused by water dripping from the forms on the newly
finished cement floors, and great care had to be exercised to protect
these floors from injury.
Fig. 2, Plate XXV, is a photograph, taken on December 15th, when
the exterior walls were finished. It shows the concrete hoist on the side
of the building, with a dumping bucket just below the level of the
fourth floor. The scaffold at the rear of the building carried the
elevator used for raising brick. The concrete mixer is shown on the
ground at the base of the concrete hoist.
As already stated, concreting on the first floor began on October
10th, and the concrete roof over the eighth story was completed on
December 27th, only 66 working days intervening between the time
of starting the first floor and the completion of the roof. On Decem-
ber 31st the tenants began moving into the practically finished build-
ing.
Fig. 2, Plate XXVII, is a photograph of the third floor, taken on
December 29th, and is typical of the upper floors.
154
DISCUSSION ON REINFORCED CONCRETE BUILDING [Papers.
Messrs. Con-
dron and Sinks.
The details of the reinforced-concrete construction are shown quite
clearly in Fig. 4. It will be seen, both in the beams and in the slabs,
that some of the reinforcing bars run straight through on the bottom,
and some are turned up to form the reinforcement for the upper face
of the beams and slabs in such manner as to provide as much steel in
the top of the beams and slabs over the supports as in the bottom of
the beams and slabs between the supports.
Fig. 5 is a bill of bars for the slabs of one floor, and Fig. 6 is the
bill of bars for one girder, taken from the working plans. These bills
of bars were prepared carefully and were shown on the working plans,
together with sketches of each different beam or girder, so that the
.Mkd.
Total
No. of Bars
Size
Length
Shape
Location
A-A
17'6"
Y^^
^
i^,toiJ,incl.
13^
'.'.
^ ^10-6^^ H
^ 6-0^^— ^-
B-B
2-M
-
14' 0"
Straight
"l9-20-22-23-24
C-C
9
"
6'0"
"
P.,
D-D
20
"
8'0"
•(•
R.
3-
^f
1
E-E
235
"
2'6"
T^l<
j
Anchors ,
v 1
F-F
5
"
14' 0"
+ Mo:
Pu
s"
V
•t
-—5-0^
\^
H-H
5
"
9' 6"
straight
I'll
X-X
224
'•
23' 0"
"
Longitudinal
Y-Y
18
"
18'0"
"
"
H-H
3
"
9 '6"
1
"
J-.T
4
"
IV' 6"
10 '6 ■
i> T-o" '^
P..
1 <
BILL OF BARS IN SLABS FOR ONE FLOOR
Fig. 5.
Contractor was able to get out the correct number of bars, and bend
them to the shape required. By following the plans, it was a simple
matter to select the right bars, and place them properly in the beams
and panels. The specifications required that no concrete should be
put in until the inspector had checked and approved the placing of the
reinforcing material. The floor bars were held the proper distance
above the forms by 2-in. lengths of round iron of the proper diameter,
while the bars in the beams were supported by two cement blocks in
each beam like those shown in Fig. 4. About 1 300 of these cement
blocks were required for the entire building, and each block was re-
inforced with two No. 8 wires, so that they could be handled safely.
These blocks were found to work perfectly, the bars resting in the
notches, thus being held in their proper places while the concrete was
poured into the beams.
PLATE XXVI.
PAPERS, AM. SOC. C. E.
FEBRUARY. 1908.
'CONDRON AND SINKS ON
REINFORCED CONCRETE BUILDING.
Fig. 1.— Reinforcing of Columns and Floor, Manufacturers' Furniture Exchange
Building.
Fig. 2.— Concreting on Second Floor, Manufacturers' Furniture Exchange
Building.
Papers.] DISCUSSION ON REINFORCED CONCRETE BUILDING
155
Fig. 7 shows the reinforcement of the stairways, of which there Messrs. Con-
were two flights running from the basement to the eighth floor. ronan m s.
The extreme simplicity of the reinforcement of this building is
evident, and, as corrugated bars were used, it was not necessary to make
bends at the ends of the bars or use other means of insuring bond, the
form of the bar giving in all cases an absolute bond between the con-
crete and the steel.
The total cost of the reinforcing bars delivered in Chicago was
almost exactly 5% of the cost of the building, and, while the special
bar used cost more than plain or other forms of reinforcing bars,
the saving which would have been made by using a less expensive one
would have been insignificant as compared with the cost of the build-
ing.
Jilk.
l.-.l
Xo. of Bars
in each Beara
'i -16 0
-21 0
eo 0
Shape
Straiofht
-5-1-1-
9-0-
-5-14-
_1.
BARS REQUIRED FOR BEAMS G^
Fig. 6.
ITnder the Chicago Building Ordinances, it is necessary for rein-
forced-concrete floors to be tested with a load at least double that for
which they are designed, and this ordinance requires that the floors thus
tested shall show no evidence of failure and shall not deflect more than
T^s of the span, or i in. for a 14-ft. span.
ITnder this ordinance, these floors were tested with a load of 350
lb. per sq. ft., covering an entire panel of 14 by 17 ft., under which
test load a deflection of less than tV in- was measured.
Later, the writers followed this method of design for the ware-
house of the Advance Thresher Company, at Kansas City (Mr. J. C.
Llewellyn, Architect), the typical reinforcement of the columns,
girders, beams, and floor slabs of which is shown in Kg. 8. These
floors were designed to carry a working load of 250 lb. per sq. ft. in
addition to the dead load. In this case, floor slabs of 8 ft. span were
156
DISCUSSION ON REINFOECED CONCRETE BUILDING [Papers.
Messrs. Con-
dron and Sinks.
adopted, and these were carried by concrete joists framing into con-
crete girders. The spacing of the columns was very irregular in the
building, but the maximum spans were 24 ft. The type of column
reinforcement was about the same as in the Manufacturers' Furni-
ture Exchange Building, except that the angles for this building
were placed with the corners out, instead of in.
FlG. 7.
Owing to the fact that this building is to be used for exceedingly
heavy concentrated loads, that is, the weight of traction engines having
12 000 lb. concentration on a wheel, the owners desired to satisfy them-
selves of the effect of concentrated loads on these floors, and therefore,
the following test was made :
PLATE XXVII.
PAPERS, AM. SOC. C. E.
FEBRUARY, 1908.
CONDRON AND SINKS ON
REINFORCED CONCRETE BUILDING.
Fig. 1.— Exterior of Manufacturers' Furniturf Ex'^hange BriLniNG. Nov. 0th, 1906.
l<'jc;. 3.— Typical Interior, Second to Seventh Stories, MANi'FACTrRERs' Fuknituke
Exchange Building.
Papers.] DISCUSSION ON REINFORCED CONCRETE BUILDING
157
Two strips of 2 by 4-in. wood, each 4 ft. long, were laid along the Messrs. Con-
centers of two adjoining 8-ft. slab spans parallel with the supporting ''™°^'^<i^'"*'s.
joists. On these two strips rested a platform on which a load of
40 850 lb. was placed, giving a concentration of 20 425 lb. on each
strip, or a concentrated load, at the center of each of these two slabs,
of 5 106 lb. per lin. ft., thus producing the same moment in the slab
TYPICAL REINFORCEMENT FOR
THE ADVANCE THRESHER COMPANY'S WAREHOUSE
KANSAS CITY, MO.
Fig. 8.
as a uniformly distributed load over a 4-ft. width of the two panels
of 1 274 lb. per sq. ft. Under this test a deflection of tV in- was
measured. Of course, the entire floor assisted in carrying such a test
load, and this is only mentioned as illustrative of the remarkable carry-
ing capacity of such floor slabs. Notwithstanding the fact that such floor
tests give astonishing results, the writers believe that floors should be
designed, not on the basis of such tests, but in accordance with con-
158 DISCUSSION ON REINFORCED CONCRETE BUILDING [Papers.
Messrs. Con- servative practice, and in all their work they have considered that,
* for floor slabs and intermediate beams, where the reinforcement passes
over the top of the slabs and beams at the ends and well into the next
panel, the moment is equal to iv I- -=- 12, and that, for end beams and
end panels, where the reinforcement can only pass in this manner
over the top at one support, w P -^ 10. The writers consider that the
dead load plus the assumed live load will stress the reinforcing ma-
terial to one-third of its elastic limit, and they use from 0.8 of 1%
to 1% of steel reinforcement having an elastic limit of 50 000 lb. per
sq. in. They have not calculated the beams as T-beams, even in such
floor construction as illustrated, but have considered them as rectangu-
lar beams with a depth equal to the distance from the top of the floor
to the bottom of the beam, and in them have used reinforcement as
great as li%, but usually it does not exceed li%, of the area of the
beam, not including any portion of the floor slab except that which is
a part of the beam section.
In designing beams and girders, the writers have used the empirical
formula, M = (450 P + 55) hd^. This formula was adopted as a
result of the study of all the tests of reinforced concrete beams which
bad been made in the various engineering laboratories of the techni-
cal schools prior to June, 1905. Up to that time, 202 beam tests had
been reported, of which 72 were of beams reinforced with Johnson
bars having an elastic limit of about 50 000 lb. per sq. in. Of these
72 tests, 80% showed ultimate strengths exceeding that given by the
formula, while only 8% developed less than 90% of the formula
strength, and the lowest test developed 78 per cent. This formula is
only used where P, the percentage of reinforcement, is more than
half of 1%, and not more than 1^%, and where steel having an elastic
limit of 50 000 lb. per sq. in. is used, and with a positive mechanical
bond. For 1% of reinforcement, the ultimate moment, M = 505 td^,
and, in general that percentage has been used. The writers have con-
sidered that three times the dead-load moment plus three times the
live-load moment is equal to the ultimate moment. Therefore, if the
dead load is equal to one-half of the live load, it would require,
theoretically, an application of four times the working live load to
reach the ultimate load. The tests made indicate that this practice is
on the safe side.
Mr. stern. E. W. Stern, M. Am. Soc. C. E.— The author states that, in view
of the uses to which the McGraw Building was to be devoted, it was
imperatively necessary that it should be designed to afford the greatest
possible resistance to the vibration of heavy machinery. Now, is
enough known about the action of reinforced concrete under vibratory
loads to make certain its suitability for this purpose?
In reinforced concrete buildings, cracks occur when there are prac-
tically no vibratory loads; under the influence of vibrations continued
Papers.] DISCUSSION ON REINFOKCED CONCRETE BUILDING 159
for a immber of years, due to running machinery in the building, is Mr. stern,
it certain that cracks will not develop, and that the reinforcing rods
will not work loose in the concrete?
Considering the design of the columns, the author assumes that
stress is transmitted into the concrete filling through the rivet heads
and lattice bars of these columns, so that both steel and concrete act
together as a unit. The speaker cannot accept this assumption. It
seems to him far-fetched and entirely problematical. If there are any
experiments to fortify the contention of the author, it would be of
benefit to this discussion to have these results.
The author likewise adopts a working stress of 750 lb. per sq. in.
on the concrete filling of the columns, equivalent to 45 tons per sq. ft.
Such a very high unit stress is so much more than has been con-
sidered good practice (being more than double that allowed in the
Building Code of Manhattan), that the author should give the Pro-
fession the benefit of the experiments upon which he bases his con-
clusions.
It is not clear to the writer, in examining the details of the
columns, how the splices of the columns were arranged at the various
joints to take care of the reduction in dimensions. For instance, the
columns in the ninth story are 17 by 17 in., back to back of angles,
whereas the next section of columns, supported on these, is decreased
suddenly to 10 by 10 in., back to back of angles. It would be of interest
to know how this change in size was taken care of in the details.
The speaker believes the type of column used to be neither as
economical nor as efficient as a box steel column made of plates and
channels. A column of this type, to take the same load, would be
made of 15-in. channels with 17-in. cover-plates, and would build up
about 21 in. square, if surrounded with 2 in. of fire-proof covering.
The columns in the McGraw Building are 29 in. square in the base-
ment and first floor, or about 40% larger in outside dimensions, and
occupy nearly twice as much space; in fact, in the lower stories, these
columns are actually about as large in outside dimensions as the steel
columns in the thirty-two story City Investing Building, at Broadway
and Cortlandt Street, designed by the firm of which the speaker is a
member.
There is actually more steel in the type of column adopted than
there would be in the channel and plate box column above mentioned,
assuming that the entire load were carried by it, without any regard
to concrete filling; and, if it were intended to fill these columns solid
with concrete and surround them with a fire-proof covering of that
material, there would be less concrete used, so that the column adopted
was extravagant both in material and in space occupied.
The author claims that the use of the type of steel column adopted
was a great convenience in erection, as it enabled the steelwork to be
160 DISCUSSION ON REINFORCED CONCRETE BUILDING [Papers.
Mr. Stern, erected ahead of the concrete work, and afforded convenient support-
ing members for the adjoining forms or for other erection work.
This argument would be equally applicable to the more economical
type of column suggested by the speaker.
The columns are spaced too closely together for a building adapted
to loft purposes. The interior columns, parallel to 39th Street, are
15 ft. 9 in. to 14 ft. 8 in. apart. A better arrangement would have
been to have these columns spaced about 18 ft. apart.
The author also states that the construction of the concrete work
in this building during the winter of. 1906-07 was entirely successful,
thus demonstrating that reinforced concrete work may be conducted
during a New York winter without material interruption. He states
that this was accomplished by covering window openings with canvas,
using salamanders, and covering the fresh concrete, as fast as poured,
with tarpaulins or hay, or both. Now, while it may be possible to ob-
tain first-class concrete work in this way, it is undoubtedly a great
expense thus to do the work, and likewise risky, as the work may freeze
at any time, especially the thin floor slabs, from underneath.
The speaker knows of a number of cases of collapse due to this
cause, and he believes that the erection of reinforced concrete work,
in which there are thin floor slabs, undertaken during freezing weather,
carries with it grave responsibility and uncertainty.
It might be interesting to compare the quantity of steel required
in reinforcing the concrete work of the McGraw Building and in that
of a steel skeleton structure. A complete steel frame structure for
the McGraw Building, computed for the same loads that were used
by the author, would weigh approximately 1 500 tons. In the McGraw
Building the steel columns weigh 655 tons, the reinforcing rods 507,
making a total of 1 162 tons, equivalent to a saving in the McGraw
tjTDe of 340 tons in the steelwork. This would amount to about $21 000,
assuming the price of steel to be about $62 a ton. This difference,
however, would most likely be more than offset in other ways in the
steel skeleton type, as there would be much less concrete required, and
the erection methods would be less expensive. Perhaps the author
made comparisons as to the cost of these different types of construc-
tion ; if so, it would be interesting to have his figures.
In an experience covering more than seventeen years in the con-
struction of buildings, the speaker has had to deal with practically
all kinds of materials, and has had charge of a number of reinforced
concrete structures. In his opinion, nothing, thus far, has been de-
vised which is comparable to the modern steel skeleton type of con-
struction for high buildings, not only for safety, but for economy,
speed in construction, and ability to make the frame as thoroughly
fire-resisting as possible.
Every condition of loading can be intelligently taken care of in a
Papers.] DISCUSSION ON REINFOllCED CONCRETE BUILDING 161
steel structure, the stress in each member of the frame being capable Mr. stern.
of complete analysis, and the knowledge at hand to-day as to what
the unit stresses should be has been so thoroughly tried out that it is
safe to say there is practically no element of vincertainty in the design
of a steel building. In a reinforced concrete building, however, the
case is otherwise. The factor of ignorance is much greater. Most of
the work is done on the premises by labor more or less unskilled.
The supervision of the work during construction is of the most
exacting nature, and requires high intelligence and unremitting
vigilance. The difficulty of getting good workmanship, and of making
the construction correspond with the plans, is very great, and, finally,
after the work is finished, grave defects of workmanship may exist in
spite of all the care exercised.
L. J. Mensch, M. Am. Soc. C. E. (by letter). — This paper has been Mr. Mensch.
read with great interest by the writer, and, while he does not doubt
that the owners are more than pleased with the strength of the build-
ing, he has to take exception to many statements made.
The structure cannot be called a true reinforced concrete build-
ing, the columns being of steel, fire-proofed by concrete, although
ostentatiously calculated as reinforced concrete columns. Neither is
it the latest type of reinforced concrete building construction; it is,
in fact, the oldest type of high building construction in which rein-
forced concrete was used. After the introduction of reinforced girder
and slab construction, many years elapsed before owners and archi-
tects could be persuaded to allow the use of reinforced concrete columns,
and, in most cases, latticed steel columns, fire-proofed by concrete,
were used. Of the numerous biiildings of this type, the writer will
mention only the ten-story Audit Office of the French Government
at the Cours de la Eeine, Paris. The statement, that the McGraw
Building is higher than hei'etofore considered practicable, must be
contradicted. The height of the Ingalls Building, in Cincinnati, is
about 220 ft. above the basement, and the height of the Pugh Power
Building, in the same city, designed by the writer, is about 180 ft.
above the basement. The latter is used for the same purpose as the
McGraw Building, and has also the same spacing of columns; and the
first section, YO by 335 ft., proved such a success that the owner built
an addition to it, making it now about 150 by 335 ft. and ten stories
high. Mr. Douglas has shown clearly the waste of steel in the columns.
It is true that very few tests of structural steel columns strength-
ened by concrete filling have been made, and the writer is pleased to
be able to mention at least one test which was made by Dr. F. von
Emperger, and published in the July number of Beton und Eisen,
1907. TwoX-beams, about 5 J in. deep and 6§ in. from center to center,
were connected by eight flat irons 2^ by I in. in a length of 13 ft. This
column failed at 100 000 lb., the I-beams buckling separately. The
162 DISCUSSION ON REINFORCED CONCRETE BUILDING [Papers.
Mr. Mensch. column was straightened out, and the space between the I-beams filled
with concrete, and tested after six weeks. The composite column
failed at 265 000 lb. The iron section contained 6.3 sq. in., the con-
crete section contained 31^ sq. in., the radius of gyration of the two
I-beams was 2.6 in., and, from this. Dr. von Emperger demonstrates
that the carrying capacity of this cokamn is to be considered as the
sum of the carrying capacities of the iron and of the concrete. He
also mentions that the concrete completely separated from the iron,
and crushed into pieces from 1^ to 3 ft. long. Test cubes, cut from
such pieces, gave an ultimate resistance of 1 120 lb. per sq. in.
Although this test may not be entirely convincing, it shows that,
in such a column, the highest working stress on the steel section may
be allowed safely, disregarding the concrete, which may be considered
as acting only as a stiffener. From this it follows that it would have
been safe to reduce the size of the columns of the McGraw Building.
The author is correct in his statement that the form work repre-
sents the most difficult part of reinforced concrete construction; and
the success of a contractor, and also the speed of erection, depend en-
tirely on his ability to organize his carpenter force, and to give his
foremen complete working drawings, omitting not the smallest detail,
even specifying the number and kind of nails; in fact, do the work
on the same basis as structural steelwork. But it is also the duty of
the engineer to design the building so that the form work is reduced
to a minimum. For example, lumber comes only in certain sizes — a
so-called 2 by 10-in. plank, is generally only 11 by ,9^ in. — and, if a
column 20 in. square is specified, the forms can only be made by
ripping the planks. On the other hand, it will be found that a column
19| by 19J in. can be formed in by using commercial lumber, and it
is absolutely necessary that the designing engineer should know the
commercial sizes of lumber, as they vary with different localities. The
same applies to girders and beams, which, as a rule, cannot be obtained
in even dimensions without considerable waste of labor and material.
The use of brackets should be carefully considered. It seems that
in most cases they are adopted for good luck, with no regard to
statical considerations. The writer has seen many brackets, the
under side of which formed an angle of 60° and more with the hori-
zontal, which were generally not more than 8 or 12 in. in length. Such
brackets add greatly to the cost, but very little to the strength, of the
structure. A little consideration would show that it would be cheaper
to use deeper girders and omit the brackets. A bracket is of im-
portance only in case the underside forms an angle of not more than
25° with the horizontal.
The layout of girders and beams should be made as simple as possi-
ble. The writer cannot say that the distribution of girders and beams
in the McGraw Building is the most economical, or the most favor-
Papers.] DISCUSSION ON REINFORCED CONCRETE BUILDING 163
able, for the form work. In the Pugh Building, the girders were Mr. jieusch.
adopted in the direction of the 21-ft. spans, and the beams in the
direction of the 14-ft. spans, and were spaced about 11 ft. apart. This
reduced the number of beams, and made the centering of the girders
much simpler, and the little excess of concrete used in the slabs, which
were reinforced in both directions — a necessity in every good design —
was more than counterbalanced by the saving in the form work and
time. The fact is that, although the floor area of this building was
more than 20 000 sq. ft., and all the walls and main partitions were
also of reinforced concrete above the third floor, the rate of progress
was a story every 16 days, with a comparatively small gang of men.
In regard to the use of a derrick tower with four swinging booms,
the writer's experience proves that the cost of the handling of the
concrete and the installation of such an outfit is considerably more
expensive than the use of a small elevator and concrete bucket, which
empties into a hopper and is hauled in two-wheeled buggies to the
place where needed.
P. E. Stevens, Assoc. M. Am. Soc. C. E. (by letter).— In the de- Mr. Stevens,
sign of the McGraw Building, careful attention has been given to
those details intended to secure continuity in the beams, even though
the New York Building Code does not permit the designer to take
full advantage of the increased strength resulting from such con-
tinuity. This feature of the design has been made the subject of
some adverse criticism, on account of the abundant reinforcement pro-
vided. The writer believes that these criticisms are not well founded.
The description and drawings of the reinforcing frames for the girders
show the steel reinforcement over the supports to be the same as that
at the center of the span, and this has been regarded by some as a
waste of material. The usual formulas for stresses in continuous
beams apply in the case of concrete only when such reinforcement is
provided. In the derivation of such formulas, three conditions are
imposed :
1. — Unyielding supports, conforming to the unstrained out-
line of the beam — usually styled supports all on a level;
2. — Spans all equal;
3. — Uniform moment of inertia throughout the length of the
beam.
The first of these conditions it is impossible to fulfill, the second
seldom prevails, and the third is commonly ignored. This is not in-
tended for cynicism, but is a simple statement of fact. Imperfect
workmanship, uneven shrinkage of concrete, and elasticity in the ma-
terial, make any assumption of "supports on a level" untenable. This
alone is sufficient reason for placing small dependence on the increased
strength due to continuity, when designing the beam.
164 DISCUSSION ON KEINFORCED CONCRETE BUILDING [Papers.
Mr. Stevens. An example of a very common and erroneous interpretation of the
third condition is found in another discussion of this subject. Mr.
Noble has said that the formulas for stresses in continuous beams
apply only when the bending moments are
"adequately met by moments of resistance, and then only when the
Linit stresses in the material furnishing this amount of resistance are
the same at the center span and the points of support."
This is decidedly at variance with the third condition imposed by
the formulas. Uniformity of stress is far from identical with uni-
formity of moment of inertia.
The amount of the bending moment over the support added to
V 1-
that at the center of the span will give a sum equal to — — in an
infinite series of uniform spans uniformly loaded. If, further, the
moments of inertia of the sections of the beam are the same through-
out its length, then, and then only, the bending moment over the
support is ^ f__j, and that at the center is .^ (^-^ )• ^^^ ^ series
of eight or more spans complying with the three conditions before
mentioned, and uniformly loaded, the span at the middle would have
approximately — within 1% — the above distribution of bending mo-
n>ents.
A design which assumes some fraction of this total, -3—, as the
moment at the support, and the remainder as the moment at the center
of the span, simply because moments of resistance have arbitrarily
been provided at those points to resist such moments, cannot be justi-
fied by any sound theory.
In order to show how erroneous any conclusions drawn from such
assumptions may be, the writer has derived the correct moments at the
supports and center of the span corresponding with various ratios be-
tween the moment of inertia for the cantilever portion and that for
the suspended portion of the span.
The beam to be considered will be assumed to be one of an infinite
series of uniform spans, uniformly loaded — approximated by a span
at the middle of a series of eight or more spans — and with supports
''all on a level." In Fig. 9 let the following nomenclature and condi-
tions govern :
A E = X\\e undeformed neutral axis of the beam, with
supports at A and E ;
A B C D E = the deformed neutral axis ;
B and D = the points of contraflexure ;
w = the uniform load per unit length ;
I = the moment of inertia of any section of A B, or
D E;
K = the moment of inertia of any section of B CD.
Papers.] DISCUSSION ON REINFORCED CONCRETE BUILDING
165
All conditions are symmetrical, therefore the elastic curve will be Mr. Stevens,
symmetrical.
a = the distance, A B, or D E;
h = the distance, B I);
ilf Q = the bending moment at A or E j
.¥^ = the bending moment at the center of the span, C;
B D will be parallel with A E.
B F is tangent to A B at B, making the angle, v. , with A E and
BI);
B O is tangent to BCD at B, making the angle, fj, with B D;
n and m are current co-ordinates of points in B G D, referred to B ;
X and y are current co-ordinates of points in A B, referred to B.
Fig. 9.
Since B and D are points of contraflexure, and bending moments
at these points are zero, the beam may be regarded as made of three
beams: two cantilevers, A B and E D, and a simple span, B D. Con-
sider first the span, B D, loaded with w per unit of length. By the
well-known theory of flexure,
" ^ WWJv ^ ~ '"^ + "'^ ^^^
Differentiate and obtain the first derivative,
d n r(j (&^ — 6 & nr -\- 4 m^)
dm 24 E K ■ ^
Make m = 0, then,
-"■'^-A '•^"
Consider now the cantilever, A B: It is loaded with the uniform
load, »•, per unit length and the end reaction from B D at B. This
end reaction is eqiml to .-, . From uniform load:
166 DISCUSSION ON REINFORCED CONCRETE BUILDING [Papers.
Bir. Stevens. deflection = -J^— (,r* — 4 a' x -{- ?, a*) (4)
42 E I ^
IV b
and, from load, -^ at -B;
w h
2
deflection = —^—.(2 cfi — 3 a^ x -\- x^) . . . (5)
and ?/, the sum of these deflections, is
2 w b (2a^ — 3a^ X -\- x^) + iv (a;* — 4 a^ x + 3 a^)
y = 24^1 -■■■■('^^
obtain the first derivative :
dy _2^vh (Sx^ — 3 a^) + w (4 ar' — 4 a^)
d^x 24 EI ^' '
make x = 0, then,
6 w b (^ — 4 w a^
*"^^- ''= WEI ('^>
Since 5 is a point of contraflexure, v. = /3, and
tan. a- = tan. /? (9)
and, from Equations 3 and 8,
w b^ 6 ui b ((- — 4 tv a^
MEK ^ 2¥WT ^ '
^^ ^
whence, ^ 3 = — ~ (11)
6 0 cr + 4 a"* I
The negative sign governing the second term of this equation is
due to the fact that the moments in the cantilever and those in the
suspended portion are of opposite sign. It will be dropped hereafter,
as it is immaterial to this discussion.
By assigning to a and h consistent values, fractions of the total
span, A D =^ I, corresponding values of j may be obtained. Such
values have been platted and a curve drawn through them (Fig. 10).
10 t
A curve has also been drawn for the values of M^^ in terms of — -,
and one for the ratio, ^>^, for comparison with f. Attention is called
.li^ 1
to the values of the various functions given by these curves corre-
1 A'
sponding with a = I (1 — .3 ^3) = 0.211 I. The curves show y = 1;
hence K — J,
lf„ = 0.00 (^^-)
which values correspond exactly with the formula for beams with uni-
form moment of inertia. It will be noted that the curves for
Papers.] DISCUSSION ON REINFORCED CONCRETE BUILDING 167
Mr. Stevens.
100 10
00 0
80 8
IS 10
60
o 50 =5
40 4
10 1
^
/
/
/
y.
/i
/.i
1
\l "
A
/ \
/ \
/
\\ \
5
/
s
"v.^^\^
0.0
u.'2 0.3
Value ol" -2-
FiG. 10.
1G8 DISCUSSION ON REINFORCED CONCRETE BUILDING [Papers.
Mr. Stevens l/" i c /^ ►- • t • i j? i
iiiid - -' intersect at a common value oi 0.1 i, indicating that lor these
values, if the depths are uniform, the stresses at the center and at
the supports will be equal. If, as is often done, y is made equal to ^
and a bending moment of ~ (— s— ) is provided for at the supports, an
overstress of 12i% will result. If, as is said to be the French practice,
_(— ^) is provided for at the center of the span, and _ (^d^)
is provided for at the supports, then — ^ 4, and il/,^ = 0.-1:70 ( — —\ .
Therefore, if the conditions of continuity and loading assumed are
realized, the result will be an actual theoretical stress 21 times as
great as that calculated. This appears to the writer to be extremely
bad designing.
It must be borne in mind that the live load to be sustained by the
beams and columns of a building is not a uniformly distributed one,
but a constantly varying set of unequal loads, sometimes concentrated
and sometimes distributed over varying areas. In a steel structure,
where each beam is an independent span, a uniform live load, with
a proper "scaling down formtila" can be specified which will enable
the designer to work very close to actual conditions. In a reinforced
concrete structure, where the floor slabs, the floor beams, and the
girders are built as continuous beams, the stress in every beam, girder,
and column is influenced by every live-load concentration, whether
it is assumed so or not. In such a case, it is manifestly impossible to
make close calculations, and the most conservative estimate must be
placed upon the value of continuity as a factor in saving material.
Also, if concentrated loads are to be provided for, the reinforcement
over the supports must be made equal to that at the center of the
span, as has been done in the design of the McGraw Building.
In the design of steel structures, experience has taught that forms
in which the stresses in each member can be determined accurately
are preferable. Many of the statically indeterminate forms, such as
multiple intersection trusses and continuous girders, have almost en-
tirely disappeared.
The workers in the younger art of reinforced concrete would do
well to give most respectful consideration to this idea of using stati-
cally determinate forms, which has become so general in the design
of structures in steel — a material the properties of which may be far
more accurately determined or controlled than those of concrete.
Vol. XXXIV. FEBRUARY, 1908. No. 2.
AMEBIC AN SOCIETY OF CIVIL ENGINEERS.
INSTITUTED 1852.
PAPERS AND DISCUSSIONS.
This Society is not responsible, as a body, for the facts and opinions advanced
in any of its publications.
THE USE OF REINFORCED CONCRETE IN
ENGINEERING STRUCTURES.
An Informal Discussion.*
By Messrs. E. P. Goodrich, Edwin Thacher, Sanford E. Thompson,
William H. Burr, T. Kennard Thomson, D, W. Krellwitz,
Guy B. Waite, and C. L. Slocum.
Presented at the Meeting of January 8th, 1908.
E. P. Goodrich, M. Am. Soc. C. E. — The use of reinforced con- Mr. Goodrich.
Crete in engineering structures has had a phenomenal development,
both as to the amount built in each succeeding year and as to the
variety of applications made. Its field of usefulness is rapidly
broadening, and its exploitation is believed to have been overdone in
a few lines.
The theory concerning the mode of action of the two materials
involved, is constantly undergoing modification, making it more per-
fect through deduction from experiment. This is the scientific method
of development of any art; and in this particular branch of the build-
ing art, it is believed that by experiment alone can proper working
stresses be determined, upon which to base all designs of structures.
Such stresses should be deduced primarily from fatigue exi^eriments,
and not be chosen as arbitrary fractions of ultimate strengths. It
is believed, further, that every careful designer should take proper
account of the secondary stresses induced in structures like buildings
and arches, by the increasing permanent set caused by repeated loading.
* The discussion of this subject, for which no formal paper was presented, is printed in
Proceedings in order that the views expressed may be brought before all members of
the Society for further discussion.
170 DISCUSSION ON THE USE OP EEINFOECED CONCRETE [Papers.
Mr. Goodrich. Experimental research is yet much needed along several different
lines connected with this subject. More light is desired as to the
cause and cure of the retrogression in the tensile strength of cement
briquettes, often disclosed. More extended compression tests are also
needed to determine the presence and amount of any retrogression in
the compressive strength of concrete. When tests, published in engi-
neering periodicals, show, at the end of 2 years, values hardly greater
than those at the end of 7 days, it would seem as if this subject needed
most careful investigation.
If possible, a cement of higher compressive strength should be de-
veloped, especially for use in concrete columns. Perhaps this is im-
possible with the materials involved, because of their very nature, and
because the strength of the aggregate has been practically reached;
but unless some considerable increase can be secured, it would seem
as if concrete columns would have to be excluded from consideration
in high building design; that is, in structures higher than perhaps six
stories. In their stead, structural steel columns would seem necessary^
but they should be heavily fire-proofed and entirely filled with a con-
crete of cheap quality. It may seem excessive to some engineers, but
it is believed that experience has shown the necessity of fully 3 in. of
good concrete fire-proofing over all extreme edges of such columns.
The best design for the steelwork of columns of this variety, is
believed to be of angles latticed or battened, of channels similarly
fabricated, or perhaps wide-flanged I-beams, or the usual Z-bar types.
Columns of the Considere variety are believed to be proper, if a
suitable relation exists between the spiral and the longitiidinal re-
inforcement, and if a sufficient quantity of each is used. In such
columns, a lower limit should be set on the quantity of each kind of
reinforcement, and an upper limit on the size of the opening between
the parts. It may not be out of place to state that the inventor of
spiral reinforcement himself uses spirals of very thick material with
a comparatively small pitch, and it is believed that a large majority
of the columns being erected at the present time, and considered of
high carrying capacity, would not disclose any appreciable excess of
carrying power if tested to failure.
In reinforced concrete columns, with longitudinal rods as the
principal reinforcement, an upper limit should be set on the percentage
which may be allowed. In addition to the fact that many laboratory
tests show lower efficiencies for rods of large diameter in concrete
columns, it would seem as if the use of rods more than IJ in. in diam-
eter, or aggregating more than 5% of the total area of the column
were of more than doubtful value, simply from the impossibility of
being certain that enough adhesion is developed to secure the theoreti-
cal compressive stress in the steel itself. It might seem as if more
Papers.] DISCUSSION ON THE USE OF REINFORCED CONCRETE 171
nearly practical conditions would be secured, in laboratory tests, if m>-- Goodrich,
all reinforcement were kept away from the ends of the concrete
columns a distance equal to at least one-fourth of the diameter of the
column.
It is believed that too little attention is given to the design of the
footings under such columns, especially with regard to a proper trans-
mission of the stress in the longitudinal rods into the foundation
concrete, and that in most work not more than half the proper number
of ties are used to prevent buckling in the vertical rods. The dis-
position of the latter, so as to prevent easy depositing of the concrete,
is imperative, and those varieties of columns in which the steel is
distributed very uniformly through the whole column section are viewed
with distrust, however superior they may be considered from a
theoretical standpoint.
Great care should also be exercised in the design of the beam and
girder reinforcement, to prevent a congestion of steel in the column
sections at the floor levels. Much ingenuity can profitably be expended
in obviating this trouble.
It is well known that the addition of steel to increase the com-
pressive strength of concrete columns is not on the side of economy of
first cost, but only of economy of floor area occupied. It would seem,
therefore, as if the best practice would be to introduce steel only to
carry bending stresses, and to use a cement of higher quality (if ob-
tainable), or a richer mixture of the commercial product, and thus
secure higher working stresses with correspondingly smaller sections.
The subject of impervious concrete is of vital importance for those
who are interested in the construction of dams, reservoirs, conduits,
sewers, and water pipes; of hardly less interest in connection with
sea walls, retaining walls, bridge abutments, and building founda-
tions; and even of considerable interest in regard to the superstruc-
tures of buildings, arch bridges, etc. Many experiments have been
made as to the perviousness of different mixtures of different aggre-
gates of different sizes, but, apparently, something further is neces-
sary. Great things are claimed for the several patented wet and dry
compounds now on the market, designed to render concrete im-
pervious, and, until further progress can be made in this line, the use
of the best of these in all concrete work is strongly recommended.
Perhaps an impervious cement will soon be evolved, produced either
by the addition of one of the present products to the practically
finished cement product, somewhat as gypsum is now added, or by
some other substance which the inventor may work out. Such a
cement is greatly to be desired, if for no other reason than to prevent
the unsightly discoloration from efflorescence which now defaces al-
most all exterior cement work. This may be partially cured by the
use of a so-called "non-staining" cement, but all those now on the
172 DISCUSSION ON THE USE OF REINFORCED CONCRETE [Papers.
Mr. Goodrich, market are unsatisfactory, either as to effect or first cost. A better
and cheaper one is essential.
Although other elements than moisture are involved in the rusting
of steel, the use of an impervious cement would have gone far toward
preventing the absolute disintegration of the metal backing of some
stucco work examined by the speaker on several occasions, and would
make one feel much safer as to the probable life of some of the re-
inforcement which has been plainly visible on the bottoms of floor
slabs when the latter were slightly scratched with a knife or other
sharp implement. It will not be very long before some of such floors
will show signs of failure, especially those in which wires of small
diameter, or sheet material of small thickness have been used for the
reinforcement.
Impervious concrete is also of vital importance in foundations,
and walls of reservoirs, conduits, etc., through which water will perco-
late slowly. It is known that at least one heavy retaining wall be-
came honeycombed to such an extent that failure resulted; and in one
high building on lower Broadway, in New York City, the sub-cellar
walls have been screened, apparently to hide the process which may
possibly be slowly producing a similar effect in that structure.
Again, the few experiments which have been made with regard to
electrolysis of embedded steel in wet concrete, together with the
astonishing phenomena observed in one reinforced concrete street car
barn, in which hot metal was sometimes encountered when a trolley
pole left the trolley wire, seem to be convincing evidence of the
necessity of using impervious concrete in all reinforced foundations
which may be in the line of electric earth currents.
It would also seem wise to use only such concrete in reinforced
concrete piles, because they are relatively slender members, and any
disintegration of either the reinforcement or the concrete in them
would be of grave moment. As to the general subject of concrete
piles, not enough is yet known. While a strong difference of opinion
may exist, it would seem as if fewer objections could be raised against
those piles which are moulded in plain sight and driven as is a wooden
pile, than against those piles which are moulded in place. The latter
rarely are properly reinforced, and it is extremely likely that the
fresh concrete will be displaced before it has properly set, by opera-
tions in their vicinity.
A very heavy hammer should be used for driving such piles, one
weighing at least as much as the pile being very important.
It is probable that impervious concrete will partially solve the
problems incident to the use of cement in sea water, whether the dis-
integration caused by the latter be chemical or mechanical in its
nature. It has already been demonstrated, at the New York Navy
Yard, for example, that a rich face mixture, rendered more im-
Papers.] DISCUSSION ON THE USE OF llEINFORCED CONCRETE 173
pervious by careful surface treatment as soon as the forms are re- Mr. Goodrich,
moved, is the best preventive of disintegration. It is hoped that
someone, therefore, vpill produce a water-proof cement.
More care than is often taken, should be exacted with regard to
the placing of reinforcement. Some hints have been given of the
evils incident to poorly designed columns, placing floor reinforcement
too close to the surface, and the dangers of electrolysis. All these
may be obviated to a great extent by the exercise of care in design
and execution. The compulsory use of reinforcement fabricated in
units, in place of separate bars in beams and girders, is advocated.
It is believed that the small possible saving which is claimed for the
latter method is more than offset by the insurance that a rod or two
will not be accidentally omitted from an important member, or a short
one thrown in to take the place of a lost longer one. Such cases have
been actually observed, even with the most perfectly organized forces,
and one superintendent of a company which still advocates separate
bars, once said the company could have some of his salary if they
would use units, because of the immeasurable lessening of responsi-
bility on his shoulders.
More attention should be paid to the subject of shear or diagonal
tension in reinforced concrete beams and girders. The fact that cer-
tain empirical systems have produced many buildings which have not
collapsed under load, is no proof of the adequacy of their reinforce-
ment in this respect. It is believed that, in much work now under
way, while the factor of safety against failure through tension or com-
pression is four or more, the margin of safety, with regard to diagonal
tension, is much smaller. The care taken with this point of design
by foreign engineers is far above that common in America. Many
more experiments, covering various ages and arrangements, are
urgently needed.
The ideas incident to the use of discrete structural members are
not applicable to the design of monolithic concrete structures. In the
latter, the continuity of the members should be recognized, and the
reinforcement of columns, beams, girders, and floors, should be ar-
ranged so as to make the parts act as rigidly connected elements. The
desig'n of colunms simply as compression members, entirely ignoring
the bending produced by unbalanced loads on rigidly connected girders,
is not considered the best practice; and the use of the factor, |, in the
moment formula is an inheritance from the older methods used in
timlier and steel. Even the use of so much reinforcement at supports
as corresponds with the factor, ^^y, is believed to be entirely inade-
quate; and the speaker ventures the prophecy that progressive failure
is taking place in many structures designed with only that quantity
of steel at the points in question.
It is further advocated, that designs be made so that tests of se-
174 DISCUSSION ON THE USE OF REINFORCED CONCRETE [Papers.
Mr. Goodrich, curity can be carried out on the very day the centering is allowed
to be removed. It is also recommended that the tests be exacted on
those dates. Such specifications, rigidly adhered to, would reduce to
a minimum the danger and number of premature failures.
Deformed rods may be better in theory, but almost no practical
proofs of their superiority have been produced, as far as known.
Laboratory tests are hardly conclusive, since many experiments on
beams actually seem to show some kinds of rods to be really detri-
mental to the best results.
More experiments are very desirable concerning the effect of the
proportion of water used in the original mixture and the effects of
continued and intermittent saturation of the concrete, upon the ad-
hesion between it and smooth rods embedded therein. Perhaps the
use of impervious concrete would solve this difficulty, irrespective of
the actual effects produced by excessive moisture. More fatigue ex-
periments, also, are essential to a full knowledge of this subject, and
the very few so far reported along all lines are worthy of the highest
commendation and the most careful study.
The compression experiments of this kind, in conjunction with
those carried to rupture on columns of the Considere type, seem really
to show the justice of allowing high stresses on such columns. As
long as the elastic limit of the concrete is not reached, since columns
rcinforced'in this way show very large deformation before final failure
(thus reducing the danger of the latter), there would seem to be no
good reason for restricting the working stress to the low figures at
present usually exacted for plain concrete or longitudinally reinforced
columns.
Nor do rods of high elastic limit appear to be advantageous, under
ordinary conditions. Since all varieties of steel have practically the
same modulus of elasticity, and since the first tension cracks in the
concrete appear at approximately the same strain in all specimens,
and consequently at the same stress, irrespective of how much higher
the elastic limit may be, the relative amount of the latter is of no
importance provided it is beyond the usual working stress.
Perhaps such rods may be of value in column work, where high
stresses are used, and they may be advantageous in the reinforcement
of long walls against shrinkage, but, even in these positions, the ad-
vantage is not evident. Reports as to actual structures of the last
mentioned kind, where no cracks have appeared, together with the
amount of steel introduced, are greatly to be desired. It is possible
that the distribution of the reinforcement is also influential to some
extent.
The character and size of the aggregate does not receive half the
attention it deserves, and the quantity of water being used, especially
in the manufacture of much cement brick, concrete blocks, and orna-
Papers.] DISCUSSION ON THE USE OF REINFORCED CONCRETE 175
mental cement work, is entirely inadequate. Very few persons are M'" fioodrich.
interesting themselves in the artistic phase of the subject, and the
results attained in most part are still considered rather crude. There
are some beautiful exceptions to this statement, however.
Experiments should be made as to means of securing more uni-
formity of color of stucco, and the application of color to cement sur-
faces should receive more study. In Europe there are some beautiful
examples of such work. While some progress has been made in devis-
ing effective and pleasing results in surface treatment of concrete
work, there is still ample opportunity for improvement. All are
familiar with the terazzo effect of good granolithic work, and most
have seen surfaces which have been picked, axed, hammered, or treated
with a sand blast. Some of the effects produced by washing, with
heavy scrubbing while quite fresh, and of etching with weak acid are
fairly pleasing, but probably the use of stucco in all its several varie-
ties will eventually predominate. Colored tile can also be used, either
in connection with stucco or in combination with selected aggregates,
and treated with water or acid to bring out the color.
With the wider use of stucco, the necessity of securing a perfect
bond between it and the foundation material will be more apparent.
Several patented and secret processes are now in use, but none is be-
yond reproach, and in this there is a wide field for improvement. When
eventually produced, such a bonding process should be used, even be-
tween parts of work done on succeeding days.
The engineer should pay more attention to the subject of forms.
If specifications, hitherto, had not been so indefinite in regard to this
item, fewer premature failures would have taken place. The practice
to be followed in the erection of at least one important arch, of design-
ing and specifying in detail all points as to the centering, can be
followed profitably in lesser structures. With this element of risk
removed, wherein the contractor has an opportunity to involve seriously
the safety of the work by his faulty design and erection of falsework,
and with the use of reinforcement in units designed by an engineer
of long and wide experience, there is no reason why reinforced con-
crete work, eventually, should not become absolutely safe and fairly
economical. Only one other point remains: the process of manu-
facture of concrete should be inspected as carefully as the production
of structural steel and the grading of timber. Then the ideal will
have been reached. Meanwhile, a careful study of the problem of
forms is exceedingly profitable, because, in the cost of finished work,
that of the labor and material thus involved often exceeds 40%, and
sometimes approaches 75%, of the total cost; and, when carefully done,
it may be reduced to 25%, where conditions are favorable. The rapid
deterioration of all form material, because of wear and tear from re-
peated use, makes this item of cost high, even when the forms are
176 DISCUSSION ON THE USE OF REINFORCED CONCRETE [Papers.
Mr. Goodrich, used a great many times. Doubtless, metal will eventually be used to
a great extent, although wood will continue to be necessary for many
parts. Staff is being used to excellent advantage, even for compara-
tively simple work, but it is not probable that its use will ever be very
extensive. Some device which will remain a permanent part of the
structure will probably be used, because these parts themselves can be
moulded in shops where few forms are necessary, and the latter can
be used a great number of times. In a similar way, the manufacture
of structural members in a factory, by machine, or in such manner
that few forms are necessary, will also be more widely developed
where conditions make it possible.
In the labor element, a reduction can often be made by handling
the forms in large units by derricks, and many devices are constantly
being invented to do away with the costly work involved in the use
of the saw, hammer, and nails. Bolts and a wrench, and work cut to
length in a mill, are more nearly ideal. In all probability, less atten-
tion will soon be given to the finish of the work as it comes from the
forms, because, for most classes of work, a better quality of surface
finish is desirable, and more than enough money can be saved by using
cruder forms, to cover the cost of such surface treatment.
Perhaps it is yet too early to discuss the subject of standardizing
the sizes of beams, percentages of reinforcement, etc., but such a step
will doubtless be taken just as soon as the art has outgrown its pres-
ent really experimental stage.
Finally, a plea is made for more rational municipal building regu-
lations and architects' specifications, in the framing of which engi-
neers should have a hand. When the designing engineer and the man
in charge of the furnishing of materials and erection of the work,
are distinct individuals, better results will be attained; and owner,
architect, engineer, and contractor will then all be striving for the
most economical and artistic structure possible.
Mr. Thaeher. Edwin Thacher, M. Am. Soc. C. E.— The effect of sea water upon
Portland cement mortar and concrete, and upon steel embedded there-
in, is a subject which has received considerable study from American
and foreign engineers and chemists, for several years past ; but the in-
vestigations thus far made appear to have resulted in very little positive
knowledge on the subject. There is considerable conflict of opinion
between foreign experts themselves, and between foreign and American
experts. What is most desired is to know why certain works have
failed, and why other works have stood the tests of many years with-
out any signs of decomposition or injury. When this is known it will
be possible to write specifications for future work in which the chemi-
cal composition of the Portland cement used, and the mixture, manipu-
lation, and placing of the concrete shall be such as will insure uni-
formly safe and satisfactory results. According to the best known
Papers.] DISCUSSION ON THE USE OF REINFORCED CONCRETE 177
European writers on the subject, the use of Portland cement concrete Mr. Thacher.
in sea water is attended with great risk of chemical decomposition,
and it is difficult and expensive to carry ovit their recommendations,
in the way of precautions to be observed to overcome partially the
risk of such a result, and their conclusions do not appear to be justi-
fied by experience in America during the past twenty years or more.
M. Feret states that no cement has yet been found which will give
absolute security against the decomposing action of sea water, that
sulphuric acid is the principal cause of decomposition, that the cement
should be low in alumina, and as low as possible in lime, that puzzolanic
material is a valuable addition to the cement, that gypsum should be
used sparingly, that fine sand used in mixing is injurious, and finally
that the mortar must be such as will give a dense and impervious
concrete.
Dr. \V. Michaelis also recommends a completely impervious mixture,
but differs from M. Feret in recommending that at least one-third of
the sand used in mixing must be very fine. If the whole body of the
concrete is not impervious, he says, this impervious layer should sur-
round the porous kernel on all sides, and even underneath. He advises
a cement rich in silica and as poor as possible in alumina and ferric
oxide, also the addition of puzzolanic material to the cement.
M. Le Chatelier considers that the aluminous compounds in Portland
cement are the direct cause of its disintegration in sea water, and ad-
vises that the alumina be replaced by oxide of iron. These foreign
authorities do not give the chemical composition of a practical Port-
land cement, such as they would recommend for work in sea water,
but satisfy themselves by condemning to a greater or less extent every
constituent of Portland cement, except silica, and no manufacturer
has yet succeeded in producing a satisfactory Portland cement contain-
ing this material only.
The writer has communicated with quite a number of American
engineers who have had extensive experience in the use of coiaerete
in sea water, and, almost without exception, the results have been
highly satisfactory, notwithstanding the fact that very little precau-
tion has been observed regarding the chemical composition of the
cement, or the impermeability of the mixture; and the damage sus-
tained has been confined mostly to points between high and low water,
apparently due to mechanical causes more than to chemical decomposi-
tion. Joseph E. Kuhn, Major, Corps of Engineers, U. S. A., Norfolk,
Va., is of the opinion that little apprehension of chemical action need
be felt when standard and well-proved brands of seasoned cement are
used. He mentions a sea wall built at Fort Monroe, just outside low
water, fifteen years ago, of 1 : 4 : 8 concrete, with two-man stone in-
corporated. It has been exposed to wave action from storms, iai which
the beach sand was stirred up, and hurled against the wall with great
178 DISCUSSION ON THE USE OF REINFORCED CONCRETE [Papers..
Mr. Thacher. force, also to tides and heavy swells from steamers. This mixture
would naturally give a very porous concrete, but it is hard and tough,
and no indications of chemical action or damage of any kind are
noticeable except between high and low water, where the wall has in
places been reduced in thickness as much as 4 in. This face has been
repaired by 1 : 2J : 4 concrete. Major Kuhn concludes that, by using
a Portland cement of good quality, and a dense and strong facing layer
when exposed to the action of the water, concrete-steel structures are
as safe in salt as in fresh water.
C. W. Staniford, M. Am, Soc, C. E., Engineer in Chief, Depart-
ment of Docks and Ferries, New York City, says :
"In the work of constructing the bulkhead or river walls around
Manhattan, which has been in progress for the past 30 years, and is
now being continued, no extra precaiitions are taken on account of the
concrete being laid in sea water, except the use of first-class material
and careful work."
Practically all the river wall, from low water up, has a granite
face, backed by concrete in place, and heavy concrete blocks set in
place with derricks from low water down, and the work is in perfect
condition, after, in many cases, a period of 30 years. This applies
also to concrete blocks laid above water at points not readily visible,
and to concrete laid en masse above low water during the past 8 years,
except in one location where, between low water and 2^ ft. above, the
concrete shows some signs of pitting, and slight disintegration, which
indicates a wear occasioned by the extreme pressure of ice during the
long low-water slack.
S. W. Hoag, Jr., M. Am. Soc. C. E., Assistant Engineer, Depart-
ment of Docks and Ferries, says :
"As regards chemical action, the experience in New York Harbor
ought to be valuable, as our waters carry sewage probably not equalled
in any smaller city. If chemical action counts for anything, I think
it would in the harbor of New York along the North and East River
waterfronts. I do not think that the possible deterioration from chemi-
cal action is likely to amount to much, lanless the exposure is in close
proximity to some chemical works. The above remarks are predicated
on first-class material and workmanship."
A committee of the Association of Railway Superintendents of
Bridges and Buildings made some investigation on the subject of con-
crete in sea water, and some of the replies to its inquiries are of in-
terest and may be noted as follows:
A, Wliere there is no ice, concrete made in air with fresh water
and sunk in sea water, works well. We would not deposit concrete
direct into sea water. Disintegration more rapid than if deposited in
blocks. Where there is large ice formation, concrete between high and
low water will disintegrate from ^ to | in. annually. Stone facing
recommended.
Papers.] DISCUSSION ON THE USE OF REINFORCED CONCRETE 179
B. Mix dry, no water, and deposit through chutes; depositing in Mr. Thacher.
blocks preferable; tides and frost have no appreciable effect on blocks.
C. Concrete deposited direct into sea water gives perfectly satis-
factory results if the materials and work are right. The cement should
contain not more than 2% sulphuric tri-oxide. Concrete should not
be leaner than 1:2:4. Stone facing preferred between high and low
water.
D. A concrete pier at Warren, E. I., built about 25 years ago, of
1 : 3 mortar, is sound except between high and low tide, where it has
worn away in places from 4 to 8 in., due to ice and tide. Current
about 8 miles an hour.
The committee reports in favor of depositing concrete direct into
sea water. It considers this method the cheapest and best, and is of
the opinion that, with good material, properly mixed and handled, and
with a granite face above low water, it will do good service.
Louis C. Sabin, M. Am. Soc. C. E., says:
''Many of the most eminent and conservative engineers consider
that most failures are due to improper specifications, proportions, and
manipulation, rather than to any defect in the cement."
William B. Mackenzie, Chief Engineer, Intercolonial Railway of
Canada,* has used concrete in eight different places in clear sea water,
and in every case disintegration has taken place between high and low
■tide, from J in. to 6 in. in depth. The concrete was generally 1:2:4.
He learned that, where sea water carries sediment, the sediment pene-
trates into the pores and coats the surface, and no disintegration takes
^lace.
Martin Murphy, Provincial Government Engineer, Nova Seotia,t
has used concrete extensively for bridge piers since 1883. Some of the
bridges were within the influence of the turbulent tides of the Bay of
Eundy, most of them exposed to heavy drift ice, and all of tEem to
extremes of temperature, yet but one failure can be recorded, and that,
in his opinion, was due to careless workmanship.
J. G. Theban, Assoc. M. Am. Soc. C. E., Engineer in Charge of the
Department of Bridges, Borough of the Bronx, New York City, has
made an interesting experiment relating to the preservation of steel
embedded in concrete in sea water. On August 24th, 1904, or some-
what more than three years ago, he sank in Pelham Bay, in 20 ft. of
vpater, a shallow wooden box, in which ten steel Thacher bars, spaced
at equal intervals, had been spiked to wooden cross-pieces. A bucket
of 1:2:4 concrete was then lowered and dumped on and around these
bars. After one month the box was raised and placed at low tide,
where it was covered with sea water twice every 24 hours. The bars
have been removed from time to time, and all have been found free
* Engineering News, October 31st, 1907.
+ Transactions, Am. Soc. C. E., 1893.
180 DISCUSSION ON THE USE OF REINFORCED CONCRETE [Papers.
Mr. Thacher. from rust. The speaker saw the hist bar removed on January 1st,
1908, and it and also the spikes with which it was fastened were free
from rust. Only a thin film of grout at most could find its way under
the bars at points where they were in contact with the wood, but no
rust could be discovered at these points,
m-. s. E. Sanford E. Thompson, M. Am. Soc. C. E. — Columns represent the
Thompson. . ,•■,•■,■,■ • , r -i r j.i
most Vital part of a building, since the failure of one may cause the
fall of the entire structure. The extreme variations in the funda-
mental assumptions in different private specifications, and also in city
ordinances, make it imperative that the subject should receive more
accurate and scientific treatment. As an illustration of the variety of
ideas as to what constitutes safety, the extremes may be cited of cer-
tain city ordinances which permit a load not greater than 350 lb. per
sq. in. on the column, and the value which is sometimes used in private
practice of 1 000 lb. per sq. in. based on the entire cross-section of the
column without appreciable reinforcement. The convincing argument,
once addressed to the speaker by a prominent architect, for the adop-
tion of the latter value in an important structure was that buildings
in the Middle West had been designed and constructed with this unit
compressive stress and were still standing.
The owners of a building frequently bring great pressure to bear
upon the designer to reduce the size of the columns in the lower
stories. This is not to be wondered at when it is considered that
their dimensions may be 30 or 36 in. square, and thus require an ap-
preciable amount of floor space.
It is well to recognize at the start that reinforced concrete columns,
of a section which will compare favorably with steel, cannot yet be
safely and economically constructed. A design after the principles
followed by Professor Burr .in the McGraw Building perhaps ap-
proaches a minimum section as closely as is possible, but, even here,
only a low unit stress can be allowed on the steel without over-com-
pressing the concrete. It may be laid down as a general principle that,
not only is it cheaper to resist compressive stress with concrete than
with steel, but also that concrete is cheaper than any combination
which may be made of steel and concrete.
In order to reduce the size of concrete columns, four distinct
methods have been used :
(1). — Rich proportions,
(2). — Vertical reinforcing steel,
(3). — Structural steel reinforcement,
(4). — Hooping or banding.
The use of a very rich mixture has much to commend it. The
ultimate strength, by using a 1 : 1 mortar, may reach 5 000 lb. per sq.
in.,* and the modulus of elasticity will also be so high that the defor-
mation will be slight.
* '-Tests of Metals," U. S. A., 1904, p. 386.
Papois.] DISCUSSION ON THE USE OF REINFORCED CONCRETE 181
The introduction of vertical steel rods is indicated by the majority Mr. s. E,
. 11. Thompson,
of tests* to be a satisfactory manner oi increasing the strength, but
the low stress which can be taken by the steel without permitting too
. great deformation of the concrete, makes this an expensive method,
and the percentage of steel is limited, not only by economical con-
siderations, but also because of the difficulty, especially when deformed
rods are used, of placing the concrete around them properly.
The use of structural-steel shapes for reinforcement has already
been so fully considered in previous discussions that no further men-
tion need be made of it here.
Hooping or banding, first introduced by Considere in France, per-
haps more than any other method of reinforcement, has caught the
popular eye, with a resulting tendency to great extremes of loading.
For this reason, it behooves engineers to examine very carefully the
underlying principles involved in this method of reinforcement and
the results of experiments thus far made.
To illustrate the position taken by many conservative engineers
on the subject of hooped columns, it may be worth while to study for
a moment the real action which takes place under loading, as shown
both by theory and tests.
When a load is placed upon the top of any column, it causes verti-
cal compression or deformation with, at the same time, a lateral ex-
pansion. The lateral expansion in concrete columns, as shown by tests
upon plain and upon reinforced columns by Mr. J. E. Howard at the
Watertown Arsenal,t and by A. N. Talbot, M. Am. Soc. C. E., at the
University of Illinois,:}; is at first very small. Any stress produced in
the steel hooping must be proportional to its deformation or stretch-
ing; hence, with small lateral expansion of the concrete, there can be
but slight stress in the hoops. For this reason, and also because of
the initial shrinkage of the concrete, which the lateral expansion must
first overcome, scarcely any stress or pull comes upon the hoops until
the concrete within them has reached a loading equal to the breaking
load in plain concrete. As this load is approached, the modulus of
elasticity of the concrete becomes very much lower, and consequently
both the vertical and lateral deformations become much greater. Then,
and not until then, does the lateral pressure begin to act appreciably
upon the hoops. In other words, up to the very crushing strength of
plain concrete, the value of the hooping is actually negligible. From
then on, the reinforcement takes practically all the load, and a high
ultimate strength may be attained, although coincident with great
shortening of the column.
It is evident that, if concrete is confined in a tube, advantage can
be taken of the added strength due to the tube. On the other hand,
* "Tests of Metals," U. S. A.. 1904, p. 386; 1905, p. 377.
t '-Tests of Metals," U. S. A., 190.5, pp. 293-336.
t Proceedings, American Society for Testing Materials, Vol. VII, 1907. p. 3H2.
182 DISCUSSION ON THE USE OF REINFORCED CONCRETE [Papers,
Thonipson. ^^ lioops are very far apart, it is evident that the concrete, when it
reaches a stress equal to the strength of plain concrete, will be thrust
out between the hoops. Professor Talbot's tests,* using a gradually
increasing load, indicate that, with ordinary spacing (the effect of
different hoop spacing is not definitely discussed in the advance report
of the tests thus far made), the hoops will effectually restrain the con-
crete within them. The effect of repeated and continued loading was
not investigated by him.
Even with the concrete restrained within the hoops, the shell of
concrete outside of them, which is necessary for fire-proofing and for
the protection of the steel, begins to crack and peel at about the same
load as that which will cause complete failure in unreinforced con-
crete. Professor Talbot, in fact, states as a general proposition that:
"Cracking and peeling of the concrete appear at loads corresponding
to the ultimate strength of the concrete."
This applies to hoops held rigidly. If the hooping is in short spiral
sections, with the ends of the wire or rods simply lapped or insecurely
fastened together, it follows, inevitably, that the spiral must give way
and unwind as soon as it is exposed by the stripping of the concrete
from the steel. Consequently, the breaking strength of a column hooped
in this way will only be effectively equal to that of an unreinforced
column.
The modulus of elasticity of the concrete within any hooping, after
the point of exterior cracking is reached, drops very rapidly, reaching,
in the two diagrams shown in Professor Talbot's paper, less than
300 000 lb. per sq. in., even at 2 000 lb. per sq. in. stress in the column,
the deformation becoming so great, in fact, that any vertical rein-
forcing steel, unless in such quantity as to take the full load, would
pass its elastic limit soon after the point of first crack,t and by its
buckling increase the surface peeling. Furthermore, from the ap-
pearance of the deformation curve, the concrete itself would seem to
be in somewhat the same condition as is steel after it has passed its
elastic limit.
When it is considered that the usual practice in concrete column
design takes no definite account of eccentric loading, or of bending
caused by expansion and contraction of floor and wall areas, and that
inferior spots may occur in any concrete, through careless mixing or
placing, it appears that the greatest care should be exercised in fixing
the unit stresses in hooped columns.
Tentative conclusions with regard to hooped column design at the
present stage of tests may be summarized as follows:
(1). — Hooping, if properly applied, increases the ultimate break-
ing strength under a single loading to double or treble the breaking
strength of a plain column.
* Proceedings, American Society for Testing Materials, Vol. VII, 1907, p. 383.
t See also Mr. Howard's tests, in " Tests of Metals," U. S. A.
Papers.] DISCUSSION ON THE USE OF EEINFORCED CONCRETE 183
(2). — The surface of concrete outside of the hooping will begin to q.^Q;^fp^^n
crack at a loading corresponding to the breaking load of an unhooped
concrete column.
(3). — Hooping, if not continuous or rigid, will peel off with sur-
face concrete, so that the effective strength of the column will be no
greater than a similar one of plain concrete.
(4). — The total vertical deformation of a hooped column is so
great at the period of first external crack that any vertical steel, unless
designed to carry the entire load, is stressed beyond its safe strength.
(5). — The ultimate breaking strength of a hooped column is no
measure of its safe strength, and formulas based on the ultimate
strength are useless.
(6). — With the present knowledge, based on tests in America and
abroad, the safe load allowed on hooped cokimns should be but slightly, '
if any, greater than on similar columns without hooping.
In spite of the favorable reports which have resulted from the
European experiments upon hooped concrete, it seems impossible to
ignore the additional facts brought ovit by American tests. Before the
hooping acts, the concrete has begun to crush, and any structural ma-
terial which has begun to crush is unsafe.
William H. Burr, M. Am. See. C. E. — Statements made in the Mr. Burr,
course of this discussion appear to indicate that, in such a general treat-
ment of the entire concrete-steel question as this, some featiires at
least of the use of concrete-steel should receive a more careful con-
sideration than would otherwise seem necessary, in view of recent
successful constructions.
Caution has been urged against using a unit working strees in the
concrete-steel combination exceeding one-tenth of the ultimate resist-
ance of plain concrete, such caution being based upon some of the
results obtained in the tests of 12-in. cubes of 1:2:4 concrete at the
Watertown Arsenal. In the consideration of experimental results
attained by testing concrete cubes, it is of the utmost importance to
know completely all the circumstances of such tests, including the
preliminary tests of the cement used and the gradations of the sand
and gravel or broken stone aggregate. If a 1:2:4 concrete should
be mixed relatively dry, and allowed to set in air and remain in a dry
building, from the time of its mixture until testing, the results at the
end of any usual test period might and probably would be quite dif-
ferent from those found at the end of the same period with a com-
paratively wet mixture kept constantly moist by sprinkling for a month
or longer subsequent to mixing. Other conditions equally productive
of varying results can be named, besides the quality of the cement.
As a matter of fact, there are numerous tests of 12-in. cubes of
1:2:4 concrete in the records of the Watertown Arsenal which show
an ultimate compressive resistance of from 3 000 to 3 600 lb. per sq. in.,
184 DISCUSSION ON THE USE OF REINFORCED CONCRETE [Papers.
Mr. Burr, and even more, at the end of three months, with increasing resistances
for longer periods. It is a conservative statement to say that well-
balanced 1:2:4 concrete, made with a good quality of Portland cement,
may give from 2 700 to 3 000 lb. per sq. in., at the end of three months,
with ultimate resistance continually increasing with age. Such con-
crete may properly and safely be expected to reach ultimate resistances
2>i from 4 000 to 4 500 lb. per sq. in. at the end of a year, results which
are jvistified by extended experience both in America and in Europe.
It is difficult to assign any satisfactory reason for the use of a work-
ing stress as low as one-tenth the ultimate resistance of concrete. It
is true that there are occasional cases of retrogression, but, with the
high grade of Portland cement available from the most reputable pro-
ducers both in America and abroad, it is reasonable to state that, with
the usual engineering inspection to which the best classes of public
work are now subjected, cement with retrogressive qualities may con-
fidently be excluded. No engineer at the present time need apprehend
sensible difficulty in securing Portland cement the resistance or
strength of which will go on increasing indefinitely, and, having
reached its maximum, hold it. Under such conditions, a working re-
sistance or permissible intensity of compression in concrete of one-fifth
to one-sixth of its ultimate, certainly affords all margin of safety re-
quired for engineering works of the best class. Indeed, probably a
somewhat higher working stress than that is justified in large struc-
tures of reinforced concrete, especially where the reinforcement is of
such a character as to give material lateral support to the concrete.
This subject is illustrated effectively by the report of a French Govern-
ment Commission bearing upon the use of reinforced concrete in
France. In that report the limit of compressive stresses allowed in
reinforced concrete is two-sevenths of the ultimate crushing resistance
of the same concrete as determined by tests of plain cubes at the age
of 90 days, with the further provision that this two-sevenths may be
increased to three-fifths if the longitudinal and transverse reinforce-
ments comply with certain prescribed conditions. This French pro-
vision would yield a safe working stress with first-class reinforced con-
crete work but little if any under 900 lb. per sq. in. The Bureau of
Buildings of the Borough of Manhattan,, New York City, therefore,
has taken a safe and satisfactory course in allowing 750 lb. per sq. in.
in such reinforced concrete work as the Thirty-ninth Street Building
in the City of New York. In fact, this latter working resistance is
conservative for the best class of reinforced concrete work of the
present time.
The apprehension regarding the reliability and durability of rein-
forced concrete work as shown by timorous expressions reminds one
strongly of the attitude which some engineers and others used to take
toward structural steel when it first came into use, twenty-five or more
Papers.] DISCUSSION ON THE USE OF REINFOKCED CONCRETE 185
years ago. It is remarkable, when one reflects that structural steel is Mr. Bun-,
practically the only structural metal which we now possess, that at the
period to which allusion is made it was frequently argued out of any
future possibility of use, as compared with such a reliable material as
wrought iron, in consequence of the erratic behavior which some struc-
tural steel members exhibited at that time. Fine cracks, started at a
punched rivet hole or sheared edge, would sometimes extend far enough
to destroy the reliable carrying power of a channel or angle or other
member. Such disclosures, with other erratic experiences, were sources
of keen apprehension to many; others, however, believed them to be
merely passing phases of difficulty, which attend the introduction of
all new materials and processes, and careful study, with intelligent
shop manipulations, has shown them to be such. Experience, of
course, has more than justified the advocates of structural steel, and
that metal has now proved to be, not only reliable, but by far the best
structural material ever yet made available to the engineer for a wide
range of purposes; indeed, wrought iron is no longer available for
structural purposes, nor has it been for a number of years.
Reinforced concrete is passing through a similar phase. It is
admirably adapted to a great range of structural purposes. Much has
already been learned in regard to it, but extending experience will dis-
close a widening fund of information of value to the engineer in its
intelligent application. As a matter of fact, more is actually known
about the carrying capacity or the ultimate resistance of concrete-
steel members than about the carrying capacity of steel columns, as
determined by actual tests. There has already been accumulated a
great mass of well-considered and well-digested experimental data re-
garding the design and construction of both concrete-steel beams and
columns, although there is need of many additional tests of some of
the latest and best forms of concrete-steel columns. On the other
hand, there are almost no tests of full-sized steel-built coUimns, made
in such a way as to disclose some of the most important fundamental
principles of design. In the present condition of actual tests of the
two classes of members, it is reasonable to believe that there may be
at least as much confidence attached to the computed ultimate carrying
capacity of both reinforced concrete beams and columns as now built
imder the best design as can be attached to the computed ultimate
carrying capacity of steel columns. Engineers have been so accus-
tomed to design and construct built-steel columns in their every-day
work that few ever reflect on the paucity, or even absence, of experi-
mental data on which to base a rational and competent design of such
members.
All that reinforced concrete construction needs for reliable results
is good cement, good inspection, and intelligent design, which, up to the
present time, it has not always had. It is one of the most useful build-
186 DISCUSSION ON THE USE OF REINFORCED CONCRETE [Papers.
Mr. Burr, jjjg inaterials which the engineer has yet had at his command, but it
must be dealt with in a manner suitable to any first-class engineering
work. There must be rational design, intelligent and effective hand-
ling, and good inspection, precisely as with structural steel; and, under
such conditions, reliable and durable results may confidently be ex-
pected.
Mr. T. K. X. Kennard THOMSON, M. Am. Soc. C. E. (by letter). — Reinforced
' concrete, like all other good things, should be protected from its
friends. Many young men, having very little knowledge of steel or con-
crete, have formed companies to build reinforced concrete structures,
and one of the first things with which they come in contact is the
fact that to obtain a contract they must bid low, another is the neces-
sity of showing the advantages of reinforced concrete over structural
steel, and, as the question of cost is the one that appeals most forcibly
to the majority of purchasers, they try to design their structure so
that the cost will be as low as, or not much higher than, plain steel.
One of the methods of doing this is to use fiber strains which are
higher than a good bridge or building designer is accustomed to allow.
Many who design reinforced concrete strain their steel bars up to
20 000 or 22 000 lb. per sq. in. — strains which bridge engineers have
countenanced only for very long spans, that is, those where the dead
loads are large compared with the live load. The recent collapse at
Quebec, where it was intended to allow a possible strain of 24 000 lb.,
and where, owing to faulty detailing,' the structure failed at about
18 000 lb., has made many doubt the wisdom of allowing such high
combinations of strains (even if only possible), which are hardly likely
to occur on any span.
It is practically impossible to ascertain the exact elastic limit of
the built-up members of a bridge — due to imperfections of workman-
ship, material, etc., etc., and therefore it is decidedly unsafe to ap-
proach too close to the elastic limit, in estimating the stresses, or to
assume that the elastic limit of the test bar is the elastic limit of the
full-sized member. There is no reason for allowing higher fiber strains
in reinforced concrete than in plain steel, as there are many elements
of uncertainty in the former which do not occur in the latter, because
far more care is required in the field work and inspection of concrete.
One source of danger, "dry concrete," is rapidly disappearing, for
dry concrete practically required an inspector for each laborer, in
order to ensure proper ramming, whereas wet concrete will almost
ram itself — the only danger being the risk of letting the water escape,
thus carrying the cement with it. A 4-in. reinforced concrete wall in
New York City was recently removed, when it was found that there
was no bond between the steel and the concrete. Not knowing the
conditions under which the wall was built, it can only be assumed
that the concrete must have been put in too dry.
Papers.] DISCUSSION ON THE USE OF REINFORCED CONCRETE 187
After the design for a reinforced concrete structure has been made, -^i''- T. k.
. , . , 1 TT <• 1 Thomson.
the three most important considerations are the proper handhng of the
material, protection from rust, and — more important still — protection
from electrolysis.
In ordinary structures where large masses of concrete are used,
buckets containing 2 cu. yd. can be dumped in place, and, if wet, re-
quire almost no handling, but, in most reinforced concrete structures
comparatively little material is used, and the utmost care is required
in handling. In many cases the extra sum paid for labor plus the
reinforcement makes the work cost as much as, or more than, a good
plain concrete structure containing twice as much concrete, in which
case it is better to put one's money into the material rather than into
the labor.
Much difference of opinion exists as to whether or not concrete
can be made water-tight. The writer's experience has been that it
can be, but may not always be, owing to carelessness, and that the mix-
ture should always be rich, that is 1 part of cement to 2 parts of
sand, with as much stone as can be covered.
The writer has seen 24-in. I-beams, which had been buried in con-
crete under the city streets for five or six years, taken out cleaner than
they were put in, and in many places showing the original blue shop
scale — no paint or oil having been used. In a few isolated places,
however, these beams were pitted with rust, showing where the water
had found its way to them. It is well known that paint and oil inter-
fere with the bond between steel and concrete. Steel caissons and
coffer-dams have been sunk in quicksand in New York City, which,
when exposed some seven years later, showed not the slightest evidence
of rust.
The writer has removed old steel and cast-iron columns, which had
been bedded in concrete and brickwork for years, which showed abso-
lutely no sign of rust. Therefore, in large buildings, carefully con-
structed, it would seem that there is almost no danger of rust, but it
is doubtful if this is true of reinforced concrete bridges, where thin
layers of concrete are used, for it has been found very difficult to put
in a roadway floor which will not allow any water to percolate through.
The danger from electrolysis is probably very much greater than
from rust, and its action is m.ore rapid. There have been cases in
New York City where a certain amount of current has been grounded
through the steel in foundations buried in concrete, and the steel has
been absolutely destroyed. For foundations, it would seem to be
safer, in many cases, to rely on mass concrete rather than on thin
slabs of reinforced concrete, which cost almost as much in the first
place. Of course, in cases where water can reach the embedded steel
and carry an electric current with it, the danger is very great, and
very certain in its action.
188 DISCUSSION ON THE USE OF REINEOKCED CONCRETE [Papers.
Mr. T. K It is probably true that steel in reinforced concrete is much less
Thomson. |-j^gjy ^^ ^.^g^ ^j^^^^ -^^ ^ g^gg^ structure covered with the best paint,
but the latter can be inspected and the former cannot.
In short, the best friends of reinforced concrete should restrict its
use to its legitimate spheres, which are many.
Mr. Kreiiwitz. D. W. Krellwitz, Jun. Am. Soc. C. E. (by letter). — Probably the
most novel form in which reinforced concrete has been used is in
transmission-line structures.
One case is the 12-mile transmission, for many thousand horse-
power at high voltage, from Decew Falls to Welland, Ont., Canada,
for which a line with reinforced concrete towers was completed in
1907. Another example is the line of towers* carrying transmission
circuits of high voltage to St. Catharines, Ont. These towers are at
present the highest monoliths that have ever been erected, being con-
siderably more than twice the height of any of the famous Cleopatra
needles.
For the elevations above ground at which it is common to support
the conductors of transmission lines (from 25 to 45 ft.), a reinforced
concrete tower, in various parts of the United States and Canada, will
cost from one to five times as much as a wooden pole. It follows at
once from this fact that there must be cogent reasons, apart from
the matter of first cost, if the substitution of reinforced concrete towers
for wooden poles on transmission lines is to be justified on economical
grounds. The electric transmission of energy from distant water-
powers to important centers of population has grown from the most
humble beginnings to the delivery of hundreds of thousands of horse-
power in the service of millions of people, and the lines for some
of this work are supported on reinforced concrete towers. Electrical
supply in Buffalo, N. Y., to the amount of 30 000 h.p., depends entirely
on the circuits from Niagara Falls which operate at 22 000 volts and,
at Tonawanda, N. Y.. are supported on reinforced concrete.
In the operation of high-voltage transmissions, during the past,
some difficulties have been met, but they have not been so serious as to
prevent satisfactory service. Nevertheless, it is being urged that
certain impediments, met in the operation of transmission systems,
would be much reduced by the substitution of reinforced concrete for
wooden poles, and it is even suggested that perhaps the first cost, and
probably the last cost, of a transmission line of this kind would be less
than with wood for supports. The argument tor reinforced concrete
in the matter of costs is that, while a tower requires a larger invest-
ment than a wooden pole, yet the smaller number of towers may reduce
the entire outlay to about the same as for wood. More than this, it
is said that the lower depreciation and maintenance charges on rein-
* Described by the writer in his paper on "• Reinforced Concrete Towers," Proceedings.
Am. Soc. C. E., Vol. XXX III, p. 572.
Papers.] DISCUSSION ON THE USE OF REINFORCED CONCRETE 189
forced concrete supports will make their final cost less than that of Mr. Krellwitz,
wooden poles.
One advantage of reinforced concrete over wood is that it will
not burn, and is probably not siibject to destruction by lightning.
The fact that reinforced concrete will not burn may make it desirable
in places where a long line passes over a territory covered with brush
or timber. In tropical countries where insects rapidly destroy wood
the use of reinforced concrete, even at a much greater cost, might be
highly desirable.
Guy B. Waite, M. Am. Soc. C. E. (by letter). — Eeinforced con- Mr. Waite.
Crete has its uses, and, up to the present, there are few things to which
it has not been found to apply.
Public opinion has changed within a very few years from serious
doubt about concrete being good for anything to that now held, that
it is good for everything.
Friends of concrete can do much damage to the cause by insisting
on pointing out personaj achievements where actually failures should
have been recorded.
It is not possible for one man to formulate a statement as to the
universal adaptability of concrete for a given purpose, in all localities
from jSTew York to California, without a knowledge of all the condi-
tions in each locality. The popular idea seems to be in most places
that concrete should be used for buildings because it is so much
cheaper than wood, and that in concrete construction the cost of almost
anything is very trifling. This view has recently been strengthened by
one of our most distinguished and respected prophets, who promises
to see that a two-family house, if it is desired, is turned out complete
in a few hours. It is to be regretted that the necessary details to enable
others to benefit by his discovery are not disclosed.
Concrete has its pros and cons which could be stretched in long
columns, thus, for example :
Against concrete: For concrete:
Xot good in tension; Good in compression;
Requires forms; Good for limited amount of shear;
Eequires time to set; Strength improves with age;
Difficult to tear down — or to fall Economical where forms are sim-
down ; pie ;
Etc. Is monolithic;
Etc.
Stone concrete, mixed in the proportion of 1:2:4, can be laid
down in almost any part of a fair-sized building, with profit, at 30
cents per cu. ft., not including forms.
An average steel colvimn, for a corresponding building, could be
erected, at a profit, for $90 per ton.
190 DISCUSSION ON THE USE OF REINFOKCED CONCRETE [Papers.
Mr. Waite. Average steel floor beams and girders, of standard sections, will
cost $60 per ton.
Beginning with the supporting columns of a building, a properly
reinforced concrete column (conservatively estimated) will carry an
average of 750 lb. per sq. in. On the other hand, suppose the
corresponding steel column to be strengthened so that it carries an
average of 16 000 lb. per sq. in. Then the required amount of ma-
terials in the two cases will be as 750 to 16 000, or about as 1 to 21.
The costs of corresponding sections of the two materials, on the
foregoing assumption, will be 30 cents and $21.96, or as 1 to 73. There-
fore the relative costs of the sections of each material to carry any
unit loading will be as 21 to 73, or about 1 to 34 in favor of the con-
crete column.
From here on, practical experiences will become useful to decide
whether the percentage of 1 to 3J in favor of concrete is the ultimate
ratio of cost, when everything is considered.
Even engineers prejudiced in favor of steel will perhaps concede
that for this steel column about 12 to 15% will have to be added to
the carrying shaft for fittings, etc. (and in the case of latticed columns
much more than this), which added amount of steel will be sufficient
to reinforce the concrete column — according to the accepted theory of
hooping. Further, if the steel column is to be protected from rust as
well as fire, the forms and the concrete material for such fire -proofing
will be substantially the same in each case.
Without taking time to go further into details, it would appear
that concrete properly used in the form of columns would certainly
have the better of the argument, when comparing costs.
The speed of erection sometimes becomes important, and, where
the reinforcement to the concrete column is made in the form of an
independent carrier, construction can proceed approximately as rapidly
as in all-steel construction.
The next objection to the concrete column is naturally the
increased size. This objection cannot be raised consistently except in
normal buildings more than six stories high, and this in the lower
stories only. If the buildings be eight stories high, the size of the
columns will only be abnormally large in the two lower stories, etc.
A well-constructed building, six stories high, should have columns of
steel of not less than a certain outward dimension, in order to give
proper rigidity to provide against eccentric loading, etc., and such
steel columns, when fire-proof, will be substantially of the size of the
solid reinforced concrete column, with an equivalent strength and
rigidity.
With development along the lines of improved reinforcement for
the concrete, in reinforced concrete columns, it is believed that in the
future the sizes of concrete columns can be reduced to meet all re-
quirements.
Papers.] DISCUSSION ON THE USE OF REINFORCED CONCRETE 191
Concrete, in connection with reinforced floors, is usually taken ^^'^- ^*'^''^®-
with a working stress of 500 lb. extreme fiber strain.
"With the usual T-section of floor construction, an average work-
ing load on the entire sectional area for compression can be taken
safely at 450 lb. per sq. ft. Estimating the steel beams to take this
load at the unit prices set forth above, the comparative costs of con-
crete and steel would be about as 35 to 49, showing an economy in
favor of concrete, other things being the same. But, in this item of
floor construction, the concrete floors have to be installed, even when
the all-steel construction is used, in order to coat the steelwork and
protect it against rust as well as fire. So that, in reality, if the con-
crete cost as much or more than the steel doing the compression work,
whatever is saved by putting this concrete to work is a clear gain,
other things being the same.
Other things do not always remain the same, however, and it is
necessary to consider the form work for the reinforced concrete con-
struction and the forms for the fire-proofing, used when steel con-
struction carries all the floor loads.
With the steel beams and girders giving the working lines and
offering ample supports for the wood forms, the modern system of
forms for fire-proofing is very materially less than where much stronger
independent framings and supports must be carefully leveled and sup-
ported for the reception of the concrete, in reinforced work.
Wliere the forms can be made in the same general manner as fire-
proofing (as in some improved systems of reinforced concrete), the
discussion of the relative costs of forms can be dropped, and one may
proceed to compare other items in the relative costs of concrete and
steel constructions. Now, assuming that forms are the same, and that
the concrete is used as a fire-proofing in each case, showing a gain for
every bit of the concrete in the reinforced scheme (which is not ob-
tained in the fire-proof scheme), then, if it is not clear that there is
economy in the reinforced scheme, it is because the concrete can be
made cheaper in the one construction than in the other. The floor
slabs will have the same loads to carry when acting as carriers from
beam to beam: the concrete, to be an effective protection to the steel
against deterioration, must be rich, so that, if the ultimate objects
are to be accomplished, the concrete should be substantially the same
in either case.
Without making the inquiry more monotonous, it would appear
that, in floors, concrete reinforced construction shows an economy in
proportion to the amount of steel it is able to replace. So that, where
economy alone is the object, a good steel job is necessary. In light
constructions (such as dwellings and hotels), where but little steel is
necessary, one cannot save as much by using concrete as where the
steel is heavier; and the saving continues to increase with the amount
of steel to be saved.
193 DISCUSSION ON THE USE OF REINFORCED CONCRETE [P^ipf'-s^
Ml-. Waite. In the foregoing comparison of relative costs in column and floor
constructions the form work is similar whether reinforced concrete or
steel and fire-proofing be used. In monolithic wall and partition con-
struction the comparison is disadvantageous when it is considered
that brick walls and partitions are laid rapidly and without the incon-
veniences of forms, and that double forms are necessary for concrete.
Further, it is very much more difficult to place the forms for straight
walls or partitions than for either columns or floors. The wall forms
are not easily held plumb, or in straight lines. The removal of the
forms for walls is also much more difficult than for either columns or
floors. The cost of common brick and mortar amounts to about 18
cents per cu. ft., and the cost of the materials composing concrete is
just about the same. So that the_ cost of laying the brickwork, for
walls of the same thickness, must be balanced by the cost of the double
forms and placing the concrete.
It is not intended to burden the reader with descriptions of the
difficulties of constructing form work for vertical structures; but, to
anyone having much experience, it must be evident that such diffi-
culties must be met. Economy in wall work must be looked for only
in heavy work, where the quantity of material placed for any given
form is sufficient to pay for it, without materially affecting the cost
of the concrete.
When no finish is looked for on the concrete work, rough forms
may be placed for from 4 to 5 cents per sq. ft. on each side of the wall;
but, for good form work, the cost will run from 7 to 10 cents per sq.
ft. on each side.
Concrete walls will be erected. They are an improved construction,
and can be handled conveniently in connection with other concrete
work in a building. The object of writing what seems to the writer
to be the truth about their construction is that economy in their con-
struction should be looked for along other lines than making double
forms for the reception of the concrete. It is believed that there will
soon be other means of erecting concrete walls and partitions, in which
concrete can more than compete with the rapid and economical brick
wall.
Mr. siocum. C. L. Sloclim, Assoc. M. Am. Soc. C. E. (by letter).— The science
and use of reinforced concrete in the United States appears to be in
its earlier stages, as compared with a longer and more thorouph ac-
quaintance and varied use in Europe. Only recently its wide application
in America has been appreciated in the manifold kinds of construction
which are now seen almost everywhere. Generally speaking, theory
and practice do not seem to be as closely allied in America as abrond.
American engineers have not learned, as well as European engineers,
that knowledge of the constituent materials and thoroughness in de-
tails of construction are more important than records in speed of erec-
Tapers.] DISCUSSION ON THE USE OP REINFORCED CONCKETE VJo
tion. Like everything new, mneh opposition, in the nature of in- Mr- siocum.
credulity, has to be overcome. For its age, reinforced concrete is
fairly well understood, and it may be said that its newness is its
greatest fault. The change in the field of design caused by the
knowledge of the properties and capabilities of the combination of
concrete and steel is now general, and is somewhat in the nature of a
revolution in construction. There is hardly a department or particu-
lar sphere of construction which has not been changed by it. Homely
and incongruous constructions in wood, steel, and stone, and other
types of construction too highly commercialized, may now, at reason-
able, cost, give place to permanent structures, which are pleasing to the
eye and are harmonious additions to the locality or latidscape. Many
types of construction in vogue or considered as good standard practice
two or three years ago are now appropriately known or should be
known as a part of the history of construction.
If reinforced concrete can be accorded the same conscientious treat-
ment and scrutiny as steel receives, there need be no hesitation about
making the change to more permanent and artistic structures, which,
if honestly built, will cause no concern or attention after they are put
in place. The mature design and construction of steelwork to-day is
accomplished by experts in that line, and these are necessary accom-
paniments of its age and maturity. The use of reinforced concrete
needs more rigid inspection in construction, for it is idle to apply care-
fully intricate formulas to designs which when constructed suffer for
want of expert superintendence and experienced labor.
In the realm of bridge construction, where ample depth is available,
there is not much doubt as to its economy. This still holds true for
spans with, comparatively shallow depth, and with light loads, in the
nature of moving concentrations. For crossings with little depth of
structure available, with heavy moving concentrations, its sphere of
usefvilness is at present advisedly confined to short spans. However,
even floor spans, up to and from 30 to 40 ft., under heavy concentra-
tions, with less than the ordinary depth, can well be investigated. Fab-
ricated units, of simple shapes, as reinforcement, with little or no shop-
work, will afford ample stiffness. Theoretical analysis, however, must
show that the unit stresses in the concrete and steel are well within
the fatigue limits. Continuous framework or an interdependent sys-
tem of units, easily put together, as reinforcements, but rigid in itself
when complete, would seem to afford as much stiffness as steel beams
bedded in concrete, which are generally calculated as carrying all the
loads independently. In true reinforced work the homogeneous com-
bination of the concrete and steel is the supporting resistance. The
full use of the two materials to carry the loads must be more economical
than the use of the one which has the concrete merely as a protection.
The writer doubts the eennniuy of hybrid construction.
194 DISCUSSION ON THE USE OF REINFORCED CONCRETE [Papers.
Mr. siocum. With old OP nmcli--used material the internal or molecular structure
and properties of which have been changed, or are in doubt, half the
usual unit stress allowed for new reinforcement, or doubling the usual
economical percentage of reinforcement, would seem to be safe and
advisable. The use of old material, of cumbersome, as well as dubious
section, of, say, 4 or 5 sq. in. net section, such as old rails, is inad-
visable for floor bridges in total length greater than the commercial
rail lengths; because attempts to develop such sections in tension are
too expensive, and are somewhat abortive.
In a series of short, independent, self-supporting arches of rein-
forced concrete, which are very flat, and are practically carried on con-
tinuous columns, the writer has used the cantilever method in finding
the stresses in the constituent materials, and has proportioned the
steel accordingly; in other words, he has considered the middle third
of each span as carried by the end thirds. These arches were calcu-
lated for the heaviest moving concentrations for highways. In beam
and slab bridges, carrying heavy trolley concentrations, where the de-
sign is somewhat hampered for depth, higher percentages of steel and
double reinforcement may have economical advantage.
In current American practice, more time can be allowed to good
advantage for this construction to attain mature strength rather than
use a green structure prematurely and perhaps lessen the efficiency of
the bond. Collections of materials of construction or equipment,
sometimes inadvertently placed on new work, give concentrations for
which the design is not calculated, and, if the work is not of sufficient
age, much damage may be done, and may not be evident until some
time after. Such consequent weakness may be brought out by fatigue,
which, under normal conditions, could not be explained. From ob-
servation, competent, well-paid superintendence and experienced work-
men of the best class give the strongest structure and the one that
fulfills all the conditions of economy.
As compared with the usual heavy masonry arches of gravity sec-
tion, the comparatively light reinforced arches give more and greater
vibrations under moving loads, principally on account of much less
bulk weight of structure. Can reinforced concrete work vibrate with
the same impunity as steelwork? The writer thinks it can, if the
working stresses are not too high, but are well within the fatigue limits.
Much interesting and instructive information could be obtained by
measuring the number of vibrations and their amplitude on bridges of
different types under different kinds and speeds of rolling loads.
Under any conditions, crossings of shallow floor construction can well
be tested for unusual loads, and consequent deflection, if any.
Other properties and characteristics being satisfactory, a greater
proportion of finely-ground cement, with a graded aggregate will, with
safety, give reinforced concrete design and construction its bold quality.
Papers.] DISCUSSION ON THE USE OF REINFORCED CONCRETE 195
which distinguishes it. Too little attention is paid to the compact- M'- siocnm.
ness or density of the mixture. The result of a few simple and inex-
pensive experiments in the measurement of voids, taking a compara-
tively short time to perform, will give a cheaper and stronger concrete.
In reinforced work, such preliminary investigations are productive of
economy.
196 MEMOIR OF CHARLES PAINE [Memoirs.
MEMOIRS OF DECEASED MEMBERS.
Note.— Memoirs will be reproduced in the volumes of Transactions. Any information
which will amplify the records as here piiuted. or correct any errors, should be forwarded
to the Secietary prior to the final publication.
CHARLES PAINE, PAST-PRESIDENT, AM. SOC. C. E.
Died July 4th, 1906.
Charles Paine was born in Haverhill, New Hampshire, on April 25th, '
1830, and died at Tenafly, New Jersey, on July 4th, 1906. Almost his
entire working life, which begdn when he was 14 years old, was spent
in railroad service, and the building of his professional position was
in that period when the railroad art was still primitive and when the
opportunities for education as a Civil Engineer, in the United States,
were confined almost to actual work in the office and in the field.
Mr. Paine was descended from Stephen Paine, who came to the
United States from England in 1638, and his family remained in New
England for eight generations. He belonged to a fine, substantial
stock, and some of his ancestors were distinguished.
Mr. Paine's school education was quite limited. In 1839, he en-
tered the College of the Order of St. Sulpice, in Montreal, where he
remained for two years and where he acquired that part of his school
education which always seemed to him the most valuable, viz., a good
grounding in French and Latin and in the elements of what old-
fashioned people call "polite education." He spent a year at an
academy in Meriden, New Hampshire, and two years in New York at
a school of which Mr, Charles Coudert was principal. This Mr.
Coudert was the father of the late Charles and Frederic Coudert,
eminent lavpyers of New York and Paris. From an uncle, William T.
Porter, editor and proprietor of the New York Spirit of the Times,
young Paine, during these two years, was permitted certain oppor-
tunities to see life and people, and he always attached a good deal of
value (and not without reason, perhaps) to the hours which he passed
in the offices of that newspaper in the company of the wits, men about
town, and famous actors and actresses. He says that in that brief
period he "drank in a love of fine things in conduct, in art, in litera-
ture, and in manners which has continued a joy to me throughout my
life."
In the spring of 1844, Paine's uncle, Governor Charles Paine, of
Vermont, took the lad into the counting-room of his broadcloth
factory, where he remained until August, 1845. Then he entered the
service of the Vermont Central Railroad, the surveys for which had
just been commenced. Of this enterprise. Governor Paine was Presi-
* Memoir prepared by Edward P. North and H. G. Prout, Members, Am. Soc. C. E.
Memoirs.] . MEMOIR OF CHARLES PAINE 1^?
dent. Here he began as rodman in the corps of Charles Brown, one
of the old engineers of the period, who enjoyed a fine reputation.
Other young men, afterward distinguished, who were associated with
Paine in this work at this time, were the late S. M. Felton, M. Am.
Soc. C. E., afterward President of the Philadelphia, Wilmington and
Baltimore Eailroad and of the Pennsylvania Steel Company; Mr.
Charles Collins, afterward Chief Engineer of the Lake Shore and
Michigan Southern; Mr. Carpenter, afterward United States Senator
from Wisconsin; and Dr. Edward H. Williams, afterward General
Superintendent of the Pennsylvania Division of the Pennsylvania
Railroad, and a member of the firm of Burnham, Parry, Williams and
Company, owners of the Baldwin Locomotive Works. Mr. Paine en-
joyed the close friendship of all these men until their lives ended, and
it is related that at the time of the Chicago fire, in 1871, Dr. Williams
and his wife, knowing that the Paines lived in Chicago, immediately
shipped by express from Philadelphia a complete outfit of clothes for
each member of the Paine family, without stopping to ask if the clothes
were needed.
In the autumn of 1847, the Vermont Central was completed into
Northfield, and, for a very short time, young Paine got a chance to
fire a locomotive, which he always regarded as one of the most valu-
able experiences of his life. The following winter he spent in the
drafting rooms of Brown and Hastings, Civil Engineers, in Boston,
and of Hinkley and Drury's Locomotive Works, where he made quite
complete drawings of all the parts of a locomotive.
Li 1848, Mr. Paine took charge of a division of the Vermont and
Canada Railroad, under Henry R. Campbell, Chief Engineer. This
road was completed in 1850. Mr. Paine then went to Montreal and
took charge of the contracts of H. R. Campbell for building a rail-
road from Rouses Point to St. Johns, and for building a branch line
from St. Lambert to intersect with the line of railway between St,
Johns and La Prairie. At this time he also had charge of the build-
ing of docks at Moffatt's Island, opposite Montreal.
It will be seen that the young man had considerable responsibili-
ties before he was of age, and he appears to have been in no way re-
luctant to assume still other responsibilities, for on May 13th, 1851,
less than a month after reaching his majority, he was married to
Olivia Blodgett Hebard, of Chelsea, Vermont. His wife belonged also
to one of the most solid New England families. She was a woman
of great cultivation of mind and of strong and beautiful character,
and they lived together in the greatest happiness until Mrs. Paine's
.death in the summer of 1897. They had six children, and four sons
now survive.
In 1855, Mr. Paine moved to Wisconsin, where he became Chief
Engineer of the Beaver Dam and Baraboo Railroad, and of the Fox
198 MEMOIR OF CHARLES PAINE [Memoirs.
Eiver Valley Eailroad, neither of which enterprises got beyond the
stage of grading the roadbed, because of the great panic of 1857. In
August, 1858, Mr. Paine became Superintendent of the Western Di-
vision of the Michigan Southern and Northern Indiana Eailroad,
which road was at that time five months behind in its pay-roll and
physically pretty nearly a wreck. The local nickname for the road
was the "Miserably Slow and Nearly Insolvent Eailroad." These con-
ditions, however, were not peculiar to that railroad in the year 1858.
Mr. Paine's connection with this railroad and its lineal successors
continued for twenty-three years. In January, 1864, he was made
Chief Engineer of the road, and on March 1st, 1872, he became Gen-
eral Superintendent of the Lake Shore and Michigan Southern" Eailway.
While in charge of this road he made such improvements and econo-
mies that by 1876 he had demonstrated his ability to carry freight for
4 mills per ton-mile, and from this, at the time, sriiall sum, pay all
the costs except for improvements, dividends, and interest on the
bonded debt.
He remained Superintendent of the Lake Shore and Michigan
Southern until he was appointed General Manager of the New York,
West Shore and Buffalo, in August, 1881. He organized and carried
through the building of this road, and upon its bankruptcy he found
himself with health impaired and with the savings of his lifetime
gone, for he himself had invested in the securities of the enterprise in
which he believed enthusiastically.
In order to get himself in condition to rebuild his fortunes, he
adopted the novel and bold scheme of traveling in Europe for a year
on borrowed money. The remedy was characteristic and highly suc-
cessful, and until the day of his death he never suffered another illness.
He served for a short time as the General Superintendent of the
New York, Pennsylvania and Ohio Eailroad, and for a few months
as Second Vice-President of the Erie, and then he went to Pittsburg
to help Mr. Westinghouse in developing the natural gas industry
through the Philadelphia Company. There he remained until Decem-
ber, 1890, he having had active executive charge of the company.
He returned to New York at the end of 1890, and opened an office
as Consulting Engineer, which office he maintained until 1899; part of
which time, however, he was General Manager of the Union Steam-
boat Line, a subsidiary Erie company, and he occupied an important
and confidential position in the administrative organization of the Erie.
From 1899 until a year before his death, Mr. Paine was General
Manager of the Panama Eailroad Company, and for a time he was
also Vice-President and a Director of that Company. This service
ended with the purchase of the Panama Eailroad by the United States
Government and the transfer of its management to the existing Canal
Commission.
Memoirs.] MEMOIR OF CHARLES PAINE 199
Mr. Paine was elected a Member of the American Society of
Civil Engineers on its reorganization in December, 1867, and was the
second man to join the Society : numbering 17 on the list of members
as it stood for the first year. He contributed to the Transactions
Paper XX : "History of the Iron Rails on the Michigan Southern and
Northern Indiana Railway," and was President of the Society during
1883.
At the time of his death, Mr. Paine was a Member of the Century
Club, in New York, an Honorary Member of the Western Society
of Engineers, and of the Engineers' Club of Cleveland, and a number
of other scientific and philosophical bodies.
Mr. Paine's personality was so extraordinary, and meant so much
to those among whom he lived, that special mention should be made
of it. His manner was commanding, but singularly gracious. He had
a dignified and impressive presence. He was of generous and en-
thusiastic temperament. He had a broad sympathy, wide reading, and
a discriminating taste in literature and art; but, beyond this, there
ib much more to be said. In every generation there are a few men
who impress their fellow men by beauty and nobility of character,
quite apart from those qualities which we may think of as purely
intellectual. They have a distinction which wealth or power or achieve-
ment cannot bestow. In the deepest recesses of our minds we recognize
these men as being the real nobility — the flower of humanity. Mr.
Paine belonged to the small group of men distinguished by character.
He had intellectual superiority, and he was a man of honorable achieve-
ment; but we, who knew him well, think of him first and respect him
most for the subtle qualities of gentle manliness. His temper was
naturally quick, and he had great personal dignity; but his courtesy
was unfailing and his modesty was sincere. He was chivalric in
thought and conduct. Honor, truth, and duty were in the roots of his
nature — inherited, bred in the bone. These were his shining charac-
teristics, by virtue of which his life was lived in a high and serene
atmosphere, and in that atmosphere dwelt with him a wife, his equal
in every way.
O^QCo
AMERICAN SOCIETY
r
OF
CIVIL ENGINEERS
March, 1908.
PROCEEDINGS - VOl! XXXIV—No. 3
N. L N^/,L
E:nginee:ring Society
William p. Morse
Published at the House of the Society, 220 West FItty-scventh Street, New York
the Fourth Wednesday of each Month, except June and July.
Copyrighted 1908, by the American Society of Civil Engineers.
Entered as Second-Class Matter at the New York City Post Office, December 15th, 1896.
Subscription, S6 per annum.
Vol. XXXIV. MARCH, 1908. No. 3.
AMEEICAN SOCIETY OF CIVIL ENGINEEES.
INSTITUTED 185 3,
PAPERS AND DISCUSSIONS.
This Society is not responsible, as a body, for the facts and opinions advanced
in any of its publications.
CONTENTS.
Papers : page.
Erection of the Bellows Falls Aich Bridge.
By L. D. Rights. Assoc. M. Am. Soc. C. E 303
Recent Developments in Pneumatic Foundations for Buildings.
By D. A. UsiNA, Assoc. Am. Soc. C. E 313
Substructure of Piscataquis Bridge, and Analysis of Concrete Work.
By G. A. Hersey, Jun. Am. Soc. C. E .' 323
Discussions :
Overhead Construction for High-Tension Electric Traction or Transmission.
By Messrs. Joseph Mayer, W. K. Archbold, Charles Rufus Harte, Farley
Osgood, and W. S. Murray 239
A New Suspension for the Contact Wires of Electinc Railways Using Sliding
Bows.
By Messrs. R. D. Coombs and Charles Rufus Harte 354
Safe Stresses in Steel Columns.
By Messrs. Henry B. Seaman, Luzerne S. Cowles, Charles M. Emmons,
Henry S. Prichard, Horace E. H(>rton, F. P. Shearwood, L. D. Rights, and
A. W. Carpenter 357
Effect of Earthquake Shock on High Buildings.
By Messrs. Uuy B. Waite, and E. G. Walker 393
The Use of Reinforced Concrete in Engineering Structures: An Informal Discus-
sion.
By Messrs. M. S. Falk, Rudolph P. Miller, Eugene W. Stern, and H. C.
Turner 397
IVlemoirs:
Calvin Easton Brodhead, M. Am. Soc. C. E 308
Georoe Thomas Nelles. M. Am. Soc. C. E 309
Herbert Franklin Northrup, M. Am. Soc. C. E 311
William Roberts, Assoc. Am. Soc. C. E 313
PLATES.
Plate XXVIII. Strain Sheet, Bellows Falls Arch Bridge 205
Plate XXIX Erection of Bellows Falls Arch Bridge 207
Plate XXX. Method of Erecting Bellows Falls Arch Bridge 309
Plate XXXr. Views of Bellows Falls Arch Bridge 311
Plate XXXII. South Abutment, Piscataquis Bridge, Showing Method of Placing
Concrete, and Coffer- Dam of Pier 3. Showing Cableway 325
Plate XXXIII. Piscataquis Bridge, Looking South, Shovving Progress of Work, and
Genei-al View of Completed Bridge 237
Plate XXXIV. Single Catenary Construction, Syracuse, Lake Shore and Northern
Railroad '. 239
Plate XXXV. Insulators Before and After Testing 7 241
Plate XXXVI. Sleet Accretion on Twig and on Wires, Winsted, Conn 343
Plate XXXVII. Wire Gridiron Under 33 000-Volt Transmission Line, and Wire
Cradle Over II 000-Volt Transmission I,ine 245
Plate XXXVIII. Wood Bar Cradle Under 6 600- Volt Lighting Circuit, and Catenary
Crossing, with Single Cut-Off Arms 249
Plate XXXIX. Improvised "Atwood's Machine" for Testing the Stiffness of
Trolley Wire 255
Plate XL. Reinforced Concrete Structure for Ice Storage, and Scaffolding to
Support Reinforcing Rods 399
Plate XLI. Reinforcement of Walls and Columns, and Reinforced Concrete
Building 801
Plate XLII. Reinforced Ccncrete Construction 303
Vol. XXXIV. MARCH, 1908. No. 3.
AMERICAN SOCIETY OF CIVIL ENGINEERS.
INSTITUTED 1852.
PAPERS AND DISCUSSIONS.
This Society is not responsible, as a body, for the facts and opinions advanced
in any of its publications.
ERECTION OF THE BELLOWS FALLS
ARCH BRIDGE.
By L. D. Rights, Assoc. M. Am. Soc. C. E.
To BE Presented April 1st, 1908.
The highway bridge across the Connecticut River at -Bellows Falls,
Vt., is interesting because, in the United States, it stands alone as an
example of a through arch with suspended floor, and also because, as
an arch, it is only surpassed in span by the two deck arches at
Niagara.
The residents of North Walpole, N. H., depend largely on the
factories at Bellows Falls, Vt., for their employment, and on the stores
for their trading. To reach the town, they were compelled to use the
old wooden toll bridge at the south end, or venture on the Sullivan
Coimty (Boston and Maine) Railroad bridge, or patronize a rather
uncertain rowboat ferry. For years they had urged a more con-
venient crossing, and this was naturally btu;ked up by the merchants
and business men on the Vermont side. The depth of the river at this
point, about 25 ft., strong objections to piers above the mouth of the
canal, owing to the vested rights of the Canal Company, and the free-
ing of the old toll bridge before another could become available, were
factors contributing to the delay of the project, which resolved itself,
largely, into a matter of cost.
Note. — 'These papers are issued before the date set for presentation and discussion.
Correspondence is invited from those who cannot be present at the meeting, and may be
sent by mail to the Secretary. Discussion, eidier oral or written, will be published
in a subsequent number of PrnceefiingR. and when finally closed, the papers, with
discussion in full, will be published in Transactions.
Papers.]
EKECTION OV ARCH BRIDGE
20J
Early in the spring of 1904, the agitation was again revived, and
interest;ed citizens brought forward new and old schemes. One that
met with considerable favor was to locate a pier on the rock in shallow
water just above the angle of the dam, shown on the map, Fig. 1.
This permitted the use of two spans, but made it necessary that these
spans should be at an angle with each other in order to reach con-
venient landing places on the shores.
BELLO>V
In March, the two towns, at their annual meeting, voted appropria-
tions to cover the cost of freeing the old toll bridge and building a new
free bridge, and appointed a joint committee to receive bids and enter
into, a contract for the work. The committee secured some preliminary
estimates on the various schemes, but, owing to the probability that
the new bridge might be used in the future for electric cars, it did not
favor the plan for two spans at an angle, but preferred a single span.
204 ERECTION OF ARCH BRIDGE [Papers.
As the preliminary estimates for a single-span bridge were unsatis-
factory, some members of the committee visited Boston and appealed
to the President of the Boston and Maine Railroad, who was inter-
ested to the extent of freeing the railroad bridge from unauthorized
foot passengers, and who responded by offering the services of J. P.
Snow, M. Am. Soc. C. E., in an advisory capacity. Mr. Snow was
naturally familiar with the general surroundings, but did not feel
that conditions warranted the preparation of an elaborate design;
therefore, he drew up general specifications, and called for bids, re-
questing each bidder to submit his own plans. Among the designs
submitted were several for truss- and suspension bridges, but all the
prices were greater than the appropriation, and the bids were rejected.
Mr. Snow was satisfied that a bridge could be built within the specified
sum, and recommended the employment of J. R. Worcester, M. Am.
Soc. C. E., which suggestion the committee accepted, Mr. Worcester
concluded to adopt an entirely different type of bridge, and decided
that a three-hinged, riveted arch with suspended floor would be the
most artistic and suitable structure for the location. He drew plans
and specifications, and, on his recommendation, separate bids were
asked for the masonry and structural steel. The results of the com-
petition were satisfactory, as several bids were received which were
within the appropriation. On the recommendation of Mr. Snow, the
contract for the masonry was awarded to Joseph Eoss and Sons, of
Boston, and the superstructure to Lewis F. Shoemaker and Company,
of Philadelphia and New York.
Design. — As will be seen by the general plan and stress sheet, Plate
XXVIII, the bridge is about 650 ft. long, and consists of a single, three-
hinged, arch span, 540 ft. from center to center of end pins, with
a short truss span at the west end, 104 ft. 8 in. from center to center
of bearings. This short span was necessary, in order to carry the
street over the Rutland Railroad. It will be noted that the roadway
is on a grade of 3.33%, running downward from the short span to the
abutment at the east end. The height of the main arch is 90 ft. be-
tween the hinge centers. The truss chords follow the lines of two
parabolas 14 ft. apart. In order to secure simplicity of detail, the
trusses do not diverge at the bottom, but stand in parallel vertical
planes, 30 ft. from center to center. This provides for a roadway, 20
ft. clear, and one sidewalk, 6 ft. wide, as shown by the cross-section.
PAPERS, AM- SOC. C. E.
MARCH, 1908,
RIGHTS ON
ERECTION OF ARCH BRIDGE.
HALF TOP CHORD PLAN
♦
Foldout
Here
♦ ♦
♦
PLATE XXIX.
PAPERS, AM. SOC. C. E.
MARCH, 1908.
RIGHTS ON
ERECTION OF ARCH BRIDGE.
1
u
,.^ ^
^
^ l^i
1 1
^
m — -"
Fig. 1.— Bellows Falls Arch BBitiGE in Progress.
-^5^^^^
^^^^ \if^
^J^ '
Sii^ y,ie«i
— -^^j-.'m^lKk
ei^:aamv^si
^N
U^ f^
^ 1 /
I Vv^
/
/
/
/
/
Fig. 2. -Connecting Arch at tre Center.
(Camera pointed upward at an angle of 15 degrees.)
Pa per;
EKKCTION OF AHCH BRIDGE
2or
number and spacing of tlio pile supports. The details of the center
bents, F, F-^, and F... are shown by Fig. 2, which gives the size of the
main posts and bracing, and indicates the splices and number of bolts.
.„- ..... DETAIL OF
BENTS F. Fj. AND F„
Bents F and F^ are as shown.
Bent F^ has outside post only,
and no bracing.
2-8"i 12"i 31)'
-44'6"
Fig. 3.
It was considered advisable, on account of the switching facilities,
to unload the material on the Vermont side of the bridge and carry
those pieces required for the east side on a standard-gauge service
track running between the towers, along the center line of the bridge.
A 10-ton stiff-leg derrick was placed on the west shore, to unload ma-
terial from the cars and transfer it to the trucks on the service track.
Two 30-h.p. hoisting engines, with two drums and four spools each,
were located at Bent E to raise the steel.
208 ERECTION OF ARCH BRIDGE [Papers.
Erection. — The masonry plans provided for piles to be driven in
the foundations for the arch, and, as the masonry contractor was well
equipped to do the work, the contract for furnishing and driving the
piles for the falsework was sublet to him. The water has an average
depth of about 25 ft., and the bottom is hard gravel. Spruce piles
were specified, in order that they might be sold to the pulp mills after
the work was completed. They were driven from 8 to 10 ft. into the
bottom, and were cut off and capped about 3 ft. above the low-water
line. The falsework towers were completed in November, and the shoes
were set on December 6th, 1904,
Two gangs were started, one from each end of the arch, and the
rivalry between them helped not a little in the rapid erection of the
work. The severe weather of the winter of 1904-05 will no doubt be
remembered, but, even in that latitude, there were breaks in the cold,
and on two separate days considerable rain fell. The fear that the
ice might go out, which would mean taking out the falsework and
everything with it, was a constant incentive to hasten the erection in
every way possible. It had not been the intention to do any work on
the ice, but after it had frozen to the thickness of about 2 ft., it was
found to be very convenient when assembling the chords, which were
handled in two sections of four panels each. The ice also acted as a
hindrance, for when the canal gates were closed, on Sundays and
holidays, the river rose about 18 in., and it was necessary to keep the
ice chopped free from the piles.
When the ice first began to form about the falsework, the structure
showed a tendency to move down stream. This was carefully noted,
account of it being taken in placing the steel. When the arch was
swung, some of the bents were found to have moved down stream about
4 in. As the load was put on the falsework, some of the bents sank
slightly, but this settlement was adjusted with wedges under the block-
ing at each point of support.
The two end panels of the lower chord and the end panel of the
upper chord were shipped riveted together. These members, each
weighing about 8 tons, constituted the heaviest pieces to be handled.
In beginning the erection, the shoes and end panels of the west
end were set with the stiff-leg derrick used for handling material from
the siding to the material trucks. On the east end a gin pole was placed
to set the shoes and end panels. Provision had been made in the plans
PLATE XXX.
PAPERS. AM. 80C. C. E.
MARCH. 1908.
RIQHT6 ON
ERECTION OF ARCH BRIDGE.
BELLOWS FALLS. VT
ROCKINGHAM, VT,
iraffi
♦
Foldout
Here
♦ ♦
♦
C. E.
IRIDGE.
I
i>
PLATE XXXI.
PAPERS, AM. SOC. C. E.
MARCH, 1908.
RIGHTS ON
ERECTION OF ARCH BRIDGE.
F'iG. 1.— The Bellows Fails Arch Bridge.
Fig. 2.— End View, -Bellows Falls Arch Bridge.
Papeis.] ERECTIOX OF AKCH BRIDGE 211
Credit for the work should be given to Mr. J. H. Fichthorn, Chief
Engineer for Lewis F. Shoemaker and Company, and to Mr. A. L.
Westbrook, Field Superintendent. The writer also wishes to ex-
press his thanks to Messrs. J. P. Snow and J. R. Worcester for the
information furnished for the preparation of this paper.
Vol. XXXIV. MARCH, 1908. No. 3.
AMEEICAN SOCIETY OF CIVIL ENGINEEES.
INSTITUTED 185 2.
PAPERS AND DISCUSSIONS.
This Society is not responsible, as a body, for the facts and opinions advanced
in any of its publications.
KECENT DEVELOPMENTS IN PNEUMATIC
FOUNDATIONS FOR BUILDINGS.
By D. a. Usina, Assoc. Am. Soc. C. E.
To BE Presented April 15th, 1908.
The purpose of this paper is to review briefly the recent and very
interesting development in foundations of the class generally used for
the high buildings being erected in the lower section of New York City.
The earth there overlies a stratum of rock, the depth of which varies
from 40 to 100 ft., and the enormous loads are carried most securely
by concrete piers built with pneumatic caissons, and resting directly
on the substratum of rock.
Prior State of the Art. — Prior to the present improvements, the
conventional type of construction was as ilkistrated in Figs. 1 and 2.
The working chamber was built with sides and roof of heavy timber
or of sheet steel with stiifeners at suitable intervals. The coffer-dam
was built up in successive sections (also of timber or stiffened steel),
the horizontal joints being made by angles on the inside, and the walls
being braced by transverse struts, where the shape and size demanded
it. The shaft was of steel tubing fastened to the roof and at the sev-
eral horizontal joints by outside angles.
Note. — These papers are Issued before the date set for presentation and discussion.
Correspondence is invited from those who cannot be present at the meeting, and may bo
sent by mail to the Secretary. Discussion, either oral or written, will be published
in a subsequent number of Proceedings, and, when finally closed, the papers, with
discussion in full, will be published in Transactions.
Papers.] PNEUMATIC FOUNDATIONS FOR BUILDINGS 213
As the structure was sunk, to bring the upper edge of each section
of the coffer-dam near the ground level, a new section of coffer-dam
and a new section of shafting were added, and the space between the
coffer-dam and the shafting was filled with concrete. When bed-rock
was reached, the working chamber and the shaft were also filled with
concrete. The finished pier consisted of two entirely separate bodies
of concrete — an inverted T-shaped portion bounded by the shafting
and the roof and walls of the working chamber, and a ring-shaped por-
tion surrounding the shaft and enclosed within the coffer-dam.
The surrounding shell, consisting of the coffer-dam and the sides
of the working chamber, whether of timber or of steel, could only be
considered a mould for the concrete and a curb or lining for holding
back the earth during the sinking of the caisson. It could not be cal-
culated as supporting any weight, but, on the contrary, was certain to
rot or corrode in time, and leave a more or less free space around the
pier. The shafting, and especially the roof, where the latter was of
metal and was left in place, presented very serious possibilities. Their
protection from corrosion depended on the care with which the con-
crete was rammed into contact with them. If either corroded to a sub-
stantial extent, it would produce a very large surface of weakness.
The permanence of these important elements of the structure, there-
fore, depended on the care of workmen, who are not to be relied on for
more care than is necessary at the moment. Furthermore, the angles
at the several horizontal joints formed grooves in the concrete from
3 to 6 in. deep. Only under unusually favorable conditions could the
shafting angles be calculated to act as supporting a share of the load
in the ratio of their horizontal area to that of the complete cross-
section of the pier; but the angles at the joints of the coffer-dam
would not transmit any substantial pressure to the concrete below
them, because the concrete would never be rammed under them suffi-
ciently. The only transmission of pressure would be to the decaying
or corroding walls, and the angles themselves would corrode in time.
The greatest area upon which the bearing strain could be calculated
correctly, therefore, was that within the inner edge of the angle-irons
(X, Fig. 2), rather than that within the inner face of the coffer-dam
{Y, Fig. 2). As a matter of fact, the latter standard was generally
used, but the error was swallowed in the large factor of safety made
necessary by the uncertainties of the problem.
214 PNEUMATIC FOUNDATIONS FOR BUILDINGS [Papers.
furthermore, the useless, and to some extent harmful, materials
left in the ground, were very expensive parts of the structure.
There were thus two powerful incentives for the elimination of
these materials from the finished structure, either by sinking the pier
without them, or by withdrawing them after use. ISTevertheless, there
was a period of many years during which little or nothing was accom-
plished.
The recent activity in high building construction in New York
City, however, making necessary a very extensive use of caissons of
this type, has witnessed the substantial elimination of every material
but concrete. The sinking of the coffer-dara and of a metal or timber
roof for the working chamber, has been rendered unnecessary, and the
steel shafting has been designed to permit its ready removal after it
has served its purpose in the sinking of the caisson. These improve-
ments have been put into practice in the foundations of the building
for the United States Express Company, at the corner of Rector Street
and Trinity Place; the New Trinity Building; the building for the
United States Realty Company, at Broadway and Thames Street, and
the Singer Building, on Broadway near Liberty Street.
Elimination of the Roof. — The most serious objection to caissons
of the style described has been the existence of the roof, constituting
a dividing plane across almost the entire cross-section. The objection
to such a dividing plane was appreciated from the earliest use of
pneumatic caissons. The late Theophilus E. Sickles, M. Am. Soc. C.
E., in 1870, and John F. O'Rourke, M. Am. Soc. C. E., in 1898, pro-
posed the removal of the roof after the sinking of the caisson and be-
fore the introduction of the concrete above the working chamber.
The Sickles caisson is shown in Eigs. 3 and 4. The roof consisted
of four segmental plates bolted to the under side of internal flanges
of the casing and attached to each other by bolts passing through
radial flanges on the under side. After sinking to the required depth,
and sealing the cutting edge with a sufficient filling of concrete to pre-
vent the entrance of water, the air was cut ofl^ and the roof removed
by withdrawing the bolts passing through the several flanges. The
caisson of the type shown had a high roof and no separate air-shaft
siapported upon the roof, as in the modern type, the cofl'er-dam or outer
shell being made air-tight throughout its height. For a caisson of this
type, the design of the roof was probably entirely satisfactory.
Pii IK-
PNEUMATIC I'OUXDATIOXS FOIt BUll.D[N(iS
215
The O'Rourke caisson. Figs. 5 and 6, utilized a similar roof in
lialf-roiind sections, but the roof was bolted on the top of the inward
flange of the casing, and the flanges connecting the segments to each
other were at the top. This would permit the filling of the working
chamber with concrete clear up to the roof before removing the latter.
Fig. 6
Fig
Fig, 8
Fig. 9
Fig. 10
The chief defect of these methods, however, appears in cases where,
in order to get the requisite weight, the concrete is filled into the space
above the roof during the sinking operation, as is usual in sinking
216 PNEUMATIC rOUXDATIOXS FOR BUILDINGS [Papers.
through earth for building foundations. In such operations it ha3
been impossible to eliminate the roof of the working chamber until
the introduction of a recent improvement which, at the same stroke,
eliminated the coffer-dam which had previously passed for a necessary
evil in sinking caissons in earth. The feasibility of the improvement
was first demonstrated by sinking all the caissons for the building for
the United States Express Company by this method, and at a sub-
stantial reduction in cost.
Elimination of the Coffer-dam. — There had been previously sug-
gested, in 1904, the elimination of the coffer-dam and roof by sinking
practically a solid pier of concrete, with only a central air-shaft and
a working chamber hollowed out of the bottom. Fig. 7 gives a suffi-
cient idea of the construction proposed. There was no distinction be-
tween different parts of the structvire, except in so far as the lower
portion of the concrete might be considered as the roof and side walls
of the working chamber, and the concrete above this might be con-
sidered as the coffer-dam extending solidly from the surrounding
earth to the shaft. It was proposed to build the whole of annular
blocks of concrete laid one above another, or to form substantially a
monolith by building up the structure in situ as fast as it was sunk.
The difficulties in the way of moulding the concrete working chamber
with suitably strong roof and sides and hardening it sufficiently in the
short time available at the works then in hand prevented the utiliza-
tion of this design, and, instead, the contractors adopted the design
shown in Figs. 8, 9, and 10.
The working chamber was built of heavy timber, and across the
top were laid angle-irons, a few inches below which was fastened a
temporary flooring. The steel shafting was supported on this flooring,
and a roof of concrete was moulded thereon to a substantial height,
and of the same outside dimensions as the working chamber. The
earth being excavated, and the chamber sunk to a sufficient depth,
another section of concrete was added. The shafting was built up
from time to time to maintain it above the concrete. After the first
section of concrete was finished, the successive sections were moulded
in place without interruption of the sinking operations; the excava-
tion and the building up proceeding of course at the same ultimate
rate, but quite independently of ench other, and the coffer-dam, reduced
to merely a mould for the concrete, being removed before the sinking
of each concrete section.
Papers.] PNEUMATIC FOUNDATIONS FOR BUILDINGS 217
In a previous design, it had been proposed to divide each section
of the coffer-dam into flat nnits which might be readily transported
and only united to each other when in place on the next lower section,
this method having the further advantage of avoiding the necessity of
breaking the air-pipes (see Fig. 1), which had been a cause of delay
with the use of sections which were completed before being put in
place; and such flat units were now found to be excellent moulding
plates, only four being needed for each section of concrete, and ex-
cessive lengths being unobjectionable, because one might overlap the
next at the corner.
The temporary flooring carried the concrete roof until the latter
was hardened, and was removed before putting on the air pressure and
the necessary lock. The angle cross-bars remained embedded in the
concrete, transmitting its weight to the timber walls, although they
were not necessary for the purpose after the concrete had hardened;
and, in fact, after reaching a comparatively slight depth, the weight
of the concrete was sustained by the skin friction and the air pres-
sure, and added weights were necessary to force the caisson down.
The cross-bars might have been designed and connected so as to per-
mit their removal after the hardening of the concrete, if such removal
had been thought of importance.
Only one accident occurred, and this demonstrated the advisability
of using timber rather than concrete for the walls of the working
chamber. The earth under one wall of the working chamber had been
excavated previously to remove the footing of an old wall. When the
first section of concrete had been moulded on this working chamber and
the mould had been removed, preparatory to sinking the concrete sec-
tion, the old material replaced in the excavation allowed one side to
settle so as to tilt the structure, and, before it could be righted, it fell
over. The concrete was tied to the working chamber only by the cross-
ing angles embedded in the base of the concrete, and swung bodily
about the upper edge of a side wall of the working chamber, thus for
a time putting its entire weight on this single wall. But the chamber
was built so strongly that it was substantially uninjured, and the
workmen in it at the time were unscathed. The accident, while in-
dicating the necessity for greater precaution in building and sinking
the first concrete section, demonstrated the practical excellence of the
design.
218 PNEUMATIC FOUNDATIONS FOR BUILDINGS [Papers.
When such a caisson was sunk to its final depth, there was no metal
or timber roof to be removed. The cost of making first a sectional
bolted roof, like that of Sickles or O'Rourke, and subsequently remov-
ing it, was saved; and, which is probably more important, the intro-
duction of concrete above the working chamber did not have to await
the sinking of the caisson. Its weight could be utilized in the sink-
ing of the structure, and this weight, in caissons passing for a great
depth through earth, is a very substantial consideration. It consti-
tuted probably the greatest of the series of advance steps under dis-
cussion.
Elimination of Shaft Lining. — The finished pier included, besides
the concrete body, the cross-bars, which are a negligible consideration,
being entirely embedded so as to prevent corrosion, and being of such
slight cross-section as not to form cleavage planes in the concrete;
and the steel shaft lining, which, at the very best, added not a pound
to the load for which the pier might be safely designed, and, at the
worst, might prove an element of weakness, and was certainly an ele-
ment of substantial expense.
The progress of improvement in eliminating the shaft lining was
the reverse of that in eliminating the roof. In the latter case, the
idea was first advanced of making the roof removable after the caisson
had been sunk; and the successful solution of the problem lay in avoid-
ing the building of a true roof. In the case of the shaft lining, the first
proposals endeavored to avoid its use entirely, but practical success
came only with the idea of sinking the caisson with a shaft lining
similar to those previously used, and removing the lining after sink-
ing and before introducing the filling of concrete.
The first idea is shown in Fig. 11. A shaft lining of moulded con-
crete is shown. To avoid excessive loss by leakage of air through the
concrete, it was proposed to coat the inner surface of the shaft lining
with air-tight material, such as a paint containing lime. The difficulty
of connecting the shaft lining to the air-lock with sufficient strength to
resist the upward air pressure on the latter was to be obviated by long
tie-rods extending from the lock to the lowest section of the shaft
lining, as indicated in dotted lines. It was also proposed in this de-
sign to eliminate the lining entirely, merely coring the concrete body
and coating the surface with paint, as above, the manner of fastening
the air-lock not being specified.
Papers.] PNEUMATIC FOUNDATIONS FOR BUILDINGS
219
^%wj!,\>«te^
220 PNEUMATIC FOUNDATIONS FOR BUILDINGS [Papers.
The first successful attempt to eliminate the shaft lining, however,
involved the i;se of a removable lining, which, while costing more than
those of common design, is usable again and again indefinitely, and,
in the long run, effects a great economy. The design used in sinking
the caissons of the new Trinity addition, and the adjoining bviilding
of the United States Realty Company, is shown in Figs. 12, 13, 14,
and 15. It was found that a comparatively small number of sections
served for the sinking of many piers. There was no material loss of
time involved in removing the sections and reassembling them for fur-
ther use. In fact, the job was completed in much less than the previous
record time for such work.
Figs. 12 and 13 show the shaft lining in place; Figs. 11: and 15
show the construction of one of the collapsible sections. Each section
was composed of two approximately semicircular plates internally
flanged for bolting to each other along one vertical edge, and a key
interposed between the opposite edges of the plates. Internal flanges
at the ends served for bolting successive sections to each other. Ladder
rungs were arranged conveniently between the flanges of the key, and
vertical guides were arranged just inside the line of the end flanges to
guide the bucket past them. In some cases the tubing was made oblong
in cross-section instead of circular. Packing was provided in all the
joints, and this was the only part of the striicture requiring renewal,
it being cheaper to provide new packing for each re-use than to try to
save the old.
Fig. 16 shows the finished pier, supposing the working chamber to
l>e built of sheet steel. The dotted line indicates the joint between
the concrete set up in sinking the pier and the filling introduced after-
ward.
Comparison with Concrete Piles. — Side by side with the lorogress
in caisson work, recent years have seen a rapid inipnnement in the
sinking or building of concrete piles in the earth. The first attempts
to substitute concrete for timber or steel in piles contemplated the
manufacture of the concrete piles above ground and the sinking of
them by one or another of the methods used for timber or steel piles.
But, at present, there are in the market several styles of concrete piles
made by first forming the excavation and subsequently filling in the
concrete. These methods permit the formation of piles of great depth
and of theoretically unlimited diameter. Starting from widely-sepa-
Papers.] PNEUMATIC FOUNDATIONS FOR BUILDINGS 221
rated points, the two arts, caisson work and pile work, have constantly
converged toward the same goal, a simple concrete column, bearing
upon a rock or similar sub-foundation in the case of caissons and some
piles, and supported by skin friction in the case of other piles.
The analogy has been carried even further by more recent improve-
ments in which vertical reinforcing rods of steel, similar to those
sometimes used in concrete piles, are embedded in the concrete of the
pier. The base of such a pier is shown in vertical section in Fig. 17,
and Fig. 18 shows a concrete pile similarly reinforced. The reinforcing
rods in the pier should extend down to the rock sub-foundation, and
are most easily introduced in that method of construction in which the
rcof of the working chamber is omitted, turn-buckles being introduced
for putting the rods under stress before embedding them in concrete.
The non-adjustable flange joints may be used for the rods which run
through the shaft, and substantially the entire length of which may
bear freely on the sub-foundation before the concrete is filled in about
them.
Most Becent Modifications. — The steel rods in the foregoing de-
signs merely reinforce the concrete. Should the concrete fail, or be
designed or built so as to shift a substantial portion of the load to the
rods, the latter would be unable to stand the strain. A recent design
includes the introduction of columns of sufficient strength to carry a
substantial load. In fact, they may be proportioned to carry all or
the greater part of the load. Fig. 19 shows the caisson sunk to rock,
and the columns in place, ready to be filled with concrete. The columns
are of ordinary style, built up of Z'^bars riveted to a central plate. One
column is embedded in the concrete from the beginning, and is wedged
up at its lower end. This column may be duplicated as often as de-
sired. Another passes down through the shaft, and is properly sup-
ported before its embedment. The shaft lining may or may not be
withdrawn, as desired.
Since it is possible to carry concrete piles in many cases to a rock
sub-foundation, where they act as true cohimns, the idea has been con-
ceived of substituting steel, with its immensely greater strength as a
column, and surrounding it with concrete, which stiffens the column
to some extent, but which performs the principal function of protect-
ing the steel from corrosion. The finished pile or column is indicated
in Figs. 20 and 21. The column is hollow, which serves to carry a
222 PNEUMATIC FOUNDATIONS FOR BUILDINGS [Papers.
water-jet for sinking the column itself, and has a surrounding shell,
which is afterward filled with concrete around and within the center
of the column. The shell may be withdrawn as the concrete is intro-
duced. The column may be shod at its lower end so as to secure a
good bearing by ramming it down on the rock.
Invention is largely accidental, and its progress is apt to be most
erratic. The writer has never observed a series of improvements pro-
gressing more logically and consistently in the same direction than
those here considered. The engineering profession owes to Daniel E.
Moran, M. Am. Soc. C. E., and John W. Doty, Assoc. M. Am. Soc. C.
E., who conceived these improvements, and to the Foundation Com-
pany, by whom they were put into practice, a very large debt for the
originality and progressive spirit with which they have met the de-
mands of modern builders for economical methods of providing founda-
tions of maximum bearing strength.
Vol. XXXIV. MARCH, 1908. No. 3.
AMEEICAN SOCIETY OF CIVIL ENGINEERS.
INSTITUTED 185 2.
PAPERS AND DISCUSSIONS.
This Society is not responsible, as a body, for the facts and opinions advanced
in any of its publications.
SUBSTRUCTURE OF PISCATAQUIS BRIDGE,
AND ANALYSIS OF CONCRETE WORK.
By G. A. Hersey, Jun. Am, Soc. C. E.
To BE Presented May 6th, 1908.
This paper gives a general description of the construction of the
Piscataquis Kiver Bridge, built for the Bangor and Aroostook Kail-
road, and also the results attained with the different classes of con-
crete used.
The Piscataquis Bridge was built during 1907, and is a part of the
"Medford Cut-off," an extension of the Northern Maine Seaport Kail-
road, a branch of the Bangor and Aroostook Kailroad. This extension
begins at the present terminus of the Northern Maine Seaport Kail-
road, and runs northward- about 28_miles until it again strikes the
main line of the Bangor and Aroostook Kailroad. It shortens the
distance between the two points on the main line 4.3 miles, reduces
the curvature considerably, and gives much easier grades.
The "Cut-off" crosses the Piscataquis Kiver in the Town of Med-
ford, and on the line of a very high horse-back — a formation peculiar
to that section of the country — which was of considerable value in the
construction of the railroad. The line follows the horse-back in a gen-
eral direction for about 14 miles, and for 6 miles skirts along its side;
it can even be said that the entire road was made from it, for, as the
Note. — These papers are issued before the date set for presentation and discussion.
Correspondence is invited from those who cannot be present at the meeting, and may be
sent by mail to the Secretary. Discussion, either oral or written, will be published
in a subsequent number of Proceedinps. and, when finally closed, the papers, with
discussion in full, will be published in Transactions.
224 BRIDGE SUBSTRUCTURE [Papers.
northerly half of the line passes through low land, material from the
horse-back was used for filling, as well as ballasting. The material in
it varies from sand to coarse gravel, and, in a few instances, clay. At
the river the best kind of gravel was found, and the hills on either
side afforded excellent sand and stone for concrete.
The grade of the railroad is 55.5 ft. above the average water level,
with about 8 ft. of water in the river.
A bridge of the deck type was adopted, with four river piers and
two shore abutments of reinforced concrete. The line crosses at a
bend in the river, the piers being placed at an angle of 55 degrees.
The total length, of the bridge is 607 ft. 10 in. About 13 tons of steel
were used for reinforcement, mostly in the two abutments, there be-
ing but little placed in the tops of each of the piers. >
The work was handled with a Lidgerwood cableway, 800 ft. long,
placed on the center line of the bridge. This cableway was used in
making all the excavation, in conveying and placing concrete, moving
machinery, and, later, in erecting the temporary trestle bridge. The
cableway clearly demonstrated its suitability in this case, and, for
rapid and profitable work, it would be hard to find anything better.
In landing the north abutment, it was necessary to go about 50 ft.
into the side of a 40-ft. bank and remove about 3 000 cu. yd. With
the cableway, all this material was saved and used directly for con-
crete and for banking coffer-dams, whereas, by almost any other method,
it would have been necessary to rehandle it several times.
The concrete was all machine-mixed, and dumped into buckets
which were run out under the cableway and carried to any part of the
bridge. The greatest number of buckets used in one day was 182, for
9 hours' work. Each bucket held 1 cu. yd.
Crib coffer-dams, of 8 by 8-in. timber, in. 8-ft. sections, were made
on the river bank. Alternate sections were floored about four tiers from
the bottom. These cribs were then set in place, and the floored sections
were loaded with rock. The outside was covered with 2-in. planks
drive'n into the river bottom as far as possible by hand-mauls. The
cribs were then banked with earth to above the water level. These
coffer-dams gave excellent satisfaction, and only in one instance was
there any trouble from leakage, and that was quickly remedied by a
generous use of straw and gravel. The pumping was done by five
centrifugal pumps having a combined discharge of 24 in., and they
were able at all times to take care of the water.
PLATE XXXII.
PAPERS, AM. SOC. C. E.
MARCH, 1908.
HERSEY ON
BRIDGE SUBSTRUCTURE.
Fig. 1.— South Abutment, Showing Method of Placing Concrete in Finishing
Abutment. Total Height, 57 Ft. (Above Ground, 45 Ft.)
Fig. 2.— Building Coffer-Dam of Pier 3, Showing Cableway.
l*«P<'i'«] BRIDGE SUBSTRUCTUEE 225
The river bottom is very rocky and gravelly, and almost as hard
and compact as if cemented. This feature could not have been im-
proved upon for the foundation. Excavations vpere carried down to
an average depth of about 5 ft. below this bottom, and all footings
rested on hard gravel through which test-bars could not be driven more
than 2 ft. The piers were liberally rip-rapped with the rock which
had been used to load tlie coffer-dams, and other larger rock.
Two mixtures of concrete were used, namely : 1:2:4 for under
water, and 1:3:5 for above water. Suitable gravel was found mixed
with sand in about the right proportions and was used without screen-
ing. Daily tests of the aggregates were made, by volumes, so that it
was known that the proper ratios were being maintained. The sand
in the gravel was very clean and sharp, and free from loam and clay.
The treatment of the aggregates was as follows: The specification
called for measurement by volume, 1 bbl. of cement, 3 bbl. of sand, and
5 bbl. of stone, etc. Test boxes, holding half a batch of gravel, were
filled with the aggregates, as placed upon the mixing platform, the
contents were screened, and the sand and rock measured separately.
If not in the right proportions more sand or more rock was added, as
the case required. By making daily tests, and inspecting closely the
materials as used, the proper proportions were maintained.
Table 1 shows the results obtained, and it is interesting to compare
them with the results from mixtures made under ideal conditions, or
those oblained where the ingredients were screened and graded more
carefully. The ratios were determined by weight as well as by volume.
In making the calculations in Table 1 for the number of cubic
feet of concrete per barrel of cement, the quantities used in the putty
coats were not considered, as so few barrels were used that they would
not have much effect on the results. The 1:2:4 mixture took 1.36
bbl., and the 1:3:5 mixture, 1.21 bbl. of cement per cubic yard of
concrete. A perfect mixture of the 1:2:4 class would require 1.46
bbl. per cu. yd., and of the 1:3:5 class, 1.11 bbl. per cu. yd., which,
as compared with the results obtained, shows that the 1:2:4 mixture
fell short x& l^^bl. per cu. yd., and the 1:3:5 mixture over-ran ^o
bbl. per cu. yd. This would indicate that the cement used in the entire
bridge was 83.88 bbl. more than called for theoretically.
The fact that the 1:2:4 mixture is short in cement and that the
1:3:5 mixture has a surplus, may be accounted for in two different
226
BRIDGE SUBSTRUCTURE
[Papers.
O o o o o o
g. i(i. CO 10 l-i ^
!> 3 2 3 tS >>»
' -! "-i r- "■ C
O UTOD0D«D
O -1 CO 00 CO
l-" -J tc CO to
COOI-'CCCO
i-iiOi-1-J-J
ooooo
ooooo
-JoaoCOCn
ooooo
^t^^a^s^o^
OM CDOSCD O
03 «». i-J. 05 to O
CJI CO CO CO to bS
O O O;. *^ GC 0>
CO JO 0» d O 1-'
ot'o'oo'oo»
oooooo
tOiO JO JOtOlO
JO I-' M- JO JO JO
bo it^ 'c» ~j o o
ooooo o
cei-icoco eo>c>
o 'c o o o o
to &" CO i-i o
to CO >-• hJ !-■ ox
'o 00 -J bi to o
CO-i iti. 1-' JO o
OS »^ oi oi m JO
1-' oo oo 00 JO en
jocnoooocn
en en o o o ci»
oooooo
£cs.
3 -i trj
o
^ » «
o 3
^ C r?
bd
w
H
cc
O
td
;>
I— I
a
Q
O
H
o
w
W
*^
o
w
a
M
;»
O
,©
d
W
td
w
5
o
PLATE XXXIII.
PAPERS, AM. SOC. C. E.
MARCH, 1908.
HERSEY ON
BRIDGE SUBSTRUCTURE.
Fig. 1.— General View. Locking South. North Abutment and Piers 1 and
Finished. Pier S Nearly Complete, and Pier 4 Being Excavated.
Fig. 3.— General View of Completed Bridge.
Papers.] BRIDGE SUBSTRUCTURE 237
ways : First, the aggregates were not graded properly, so that the voids
were not completely filled; second, the quantities of the aggregates
used for the different mixtures were not always exactly the same. The
material was loaded into the mixer by wheel-barrows, the necessary
quantity for a wlieel-barrow for each mixture was determined, and
they were all supposed to be loaded the same; in this, however, there
was bound to be some variation.
For 1 bbl. of cement, or 4 bags (all the cement being in bags) 8
wheel-barrows of the aggregate were used in the 1:3:5 mixture, and
6 wheel-barrows of the aggregate in the 1:2:4 mixture. A check
was had on the quantities used by the space occupied by the completed
batch in the bucket, after being dumped from the mixer, as the
buckets each held 1 cu. yd., it was found by test samples just how full
they should be for the two different mixtures. Then, again, the ag-
gregates not being uniformly graded by Nature would have a tendency
to throw the resultant, cubic feet per barrel, under or above the
theoretical results obtained from perfect mixtures. It seems, however,
that where suitable ingredients can be found in their natural state,
free from loam and clay — although a small percentage of either will
not decrease the strength of the concrete — that as good work at less
cost per yard can be obtained as where the sand is screened from the
gravel and they are again mixed artificially; for, when the ingredients
go into the mixer in their natural state, the machine has to do less
work in mixing the cement with them, than when the sand, rock, and
cement go in separately, for the mixer has not only to mix the cement
in, but the sand and rock as well. Thus, with a mixer running for
the same time, under the two different conditions, it would seem that
a better mixture could be made from the natural ingredients. There
were instances during the progress of the work when the resultant
mixtures agreed exactly with the required quantity of cement per barrel.
This would indicate that in such cases the voids were completely filled,
the sand filling the interstices of the rock and the cement those of
the sand.
The piers were designed with round noses, having a slight batter.
At a point well above high water, on the front ends, a circular break-
water was made, having a batter of 2 : 3 and extending down to with-
in 3 ft. of the footing course. The forms for these noses were made
of 2-in. plank, about 4 in. wide, sections being built up in 8-ft. lengths
228 BRIDGE SUBSTRUCTURE . [Papers.
as the concrete advanced. With plank of this width, the circular
form could be made very readily, and with very smooth surfaces.
The concrete was mixed wet, no tamping being required, other than
the shoveling over it received after being dumped from the bucket.
Care was taken, however, that the sides of the forms were well worked
around with shovels, which kept the rock back and allowed the soft
material to come to the outside. The piers when stripped and dry
received a coat of whitewash. The writer is not wholly convinced of
the worth of this coat for work of this class, as it usually cracks and
peels off. Where a good surface has been obtained, he would prefer to
omit the whitewash coat.
Although the season was unusually wet, the progress of the work
was delayed only for a few days. The river is affected rapidly by the
rains, there being no storage in its water-shed, and the water rises and
falls quickly. High water was encountered only once, when the sec-
ond and third piers were first started, but the only damage was the
washing away of a little of the coffer-dam embankment.
In the construction of the temporary falsework, piles were driven
from a driver on a barrel raft. In no case could the piles be driven
more than 5 ft., and the average was about 3 ft. This proved fully
the firmness of the entire river bottom, as found during the excava-
tion at the pier locations. Most of the piles were furnished with steel
points. For absolute safety, piles should not be driven without some
protection for the point, no matter through what kind of ground, as
one can never tell what material a pile is to pass through.
The contractor for the concrete work was Mr. J. B. Mullen, who has
had wide experience in similar work. Moses Burpee, M. Am. Soc. C.
E., is Chief Engineer of the Bangor and Aroostook Railroad. W. S.
McEetridge, M. Am. Soc. C. E., was Engineer of Construction, in
charge of the "Medford Extension," and the writer was Engineer in
Charge at the bridge.
Vol. XXXIV. MARCH, 1908. No. 3.
AMEEIOAN SOCIETY OF CIVIL ENGINEERS.
INSTITUTED 1852.
PAPERS AND DISCUSSIONS.
This Society is not responsible, as a body, for the facts and opinions advanced
in any of its publications.
OVEEHEAD CONSTRUCTION FOR HIGH-TENSION
ELECTRIC TRACTION OR TRANSMISSION.
Discussion.*
By IMessrs. Joseph Mayer, W. K. Archbold, Charles Eufus Harte,
Farley Osgood, and W. S. Murray.
Joseph Mayer, M. Am. Soc. C. E. — This paper, in the main, is ^r Mayer,
an interesting collection of data and tables, useful in the design of
overhead contact and transmission lines.
The tables of wind velocities and pressures are especially useful
for forming a correct opinion of the actual pressures. More stress
might be laid on the fact that the observations of the Weather Bureau
are made on the tops of high buildings, while the transmission lines,
and especially the contact lines, are near the surface of the ground,
where the wind pressures are much less. It would also be reasonable
to assume less ice on the contact wire than on steel carrying strands,
especially on lines of large traffic. Mr. Coombs' recommendations,
in regard to wind pressures and unit strains, are generally reasonable.
His paper, however, in common with most writings on the same sub-
ject, suffers from an insufficient consideration of the bending strains
in the wires. In many designs, these bending strains are greater than
the tensions, and their neglect leads inevitably to the selection of un-
safe designs. They vary so greatly in amount that they cannot be
provided for by neglecting them and adopting a large, but uniform
factor of safety.
*This discussion (of the paper by R. D. Coombs, M. Am. Soc. C. E., printed in Pro-
ceedings for December, 1007), is printed in Proceedings in order that the views expressed
may be brought before all members for further discussion.
230 DISCUSSION ON OVERHEAD ELECTRIC TRACTION [Papers.
Mr. Mayer. Mr. Coombs suggests for discussion a suspension from a single
steel strand with 300-ft. spans and a distance of 6J ft. from the points
of suspension of the strand to the wire. Taking the wire as horizontal,
and at the highest temperature, this, with a distance of 6 in. from
the lowest point of the strand to the wire, gives a maximum vertical
deflection of 6 ft. for the strand. He prefers this to the double
catenary and strandless suspension. What justifies this preference,
and what makes a superior suspension?
To have adequate conductivity, the wire must be copper; to give
a smooth path for the bow, it must be solid; it is impossible to
make it straight, but, under the pressure of the sliding bow, especially
with high train speeds, it must have a large minimum radius of verti-
cal curvature. The wire should not deviate horizontally far from the
center line of track, or, if hung on the side, from a line parallel to it.
It must remain safely suspended under the influence of its weight and
that of sleet, the wind pressure, the prjessure of the sliding bow, and
the changes of temperature. The wire and its supporting structure
should interfere as little as possible with the view of the signals.
These ends should be attained by the simplest means, entailing the
least cost of construction and maintenance. The bow lifts the wire,
and the curvature of its motion, and not that of the freely hanging
wire, must be considered. If the wire is supported at short intervals,
it is lifted by the passing bow to positions above its supports; if these
are rigid, the bow, at high train speed, oscillates rapidly up and down.
Excessive bending strain in the wire, and jumping of the bow, with
sparking, may result.
To ascertain whether the bow will run smoothly, its equivalent
weight, the train speed, the cross-section of the contact wire and its
tension, the distance apart of the suspenders, their weight, and that
of the carrying strand, and the nature of the connection of the wire
to the suspenders must be known. For high train speeds, a small
equivalent weight of the bow is essential. Long bows are inevitably
heavy; high train speeds, therefore, require short bows and small
lateral deflections of the contact wire. The equivalent weight of the
bow, however, depends even more on the design adopted than on its
length. If smooth running is called for, at high speed, with an in-
ferior heavy bow, short spans are inevitable with all suspensions. The
rapid vertical oscillation of the bow is avoided in the strandless and
the Siemens-Schuckert suspension described by Mr. Coombs.
In the strandless suspension, with long spans, there is a large
change in the direction of motion of the bow at the infrequent sus-
penders; to make this practicable at high 'speed, the curvature of this
motion must be chosen so that where it is convex downward the bow
will not jump, and where it is convex upward neither the wire nor the
bow nor the suspender will suffer from the increased pressure. In all
Papers.] DISCUSSION ON OVERHEAD ELECTKIC TRACTION 231
suspensions there are large changes in the direction of motion of Mr. Mayer,
the bow at low overhead crossings and tnnnel entrances, and some-
times at grade crossings. With inferior, heavy sliding bows a perfect
design of the contact line for high speeds at these points is difficult
or impracticable. A suspender fitted to ch.^nge the variable direction
of approach of the sliding bow into another variable direction of its
departure, by a transition curve of large least radius at all tempera-
tures, is here needed with all suspensions.
To obtain a safe wire, its maximum strain must nowhere and
never exceed about three-fourths of its elastic limit. It is exposed
to bending strains and tensions. The former are often much larger
than the latter. In catenary suspensions, a large grooved copper wire,
about 0.3 in. wide and 0.6 in, in height of cross-section, is suspended
from steel strands made up of very small wires. The copper wire has
an ultimate strength of from 50 000 to 60 000 lb., the steel wires,
140 000 lb. or more. The modulus, E, of copper wires is 16 000 000,
that of steel strands is 26 000 000 lb. per sq. in. of solid section. It
is evident that the bending accompanying changes in vertical and
horizontal deflections will produce much more serious bending strains
in the large and weak copper wire than in the small and strong steel
wires. For calculating them, the vertical and horizontal deflections
of the wire under all conditions of load, wind pressure, pressure of the
sliding bow, and changes of temperature must be determined. It is
easy to provide steel ropes strong enough to carry the wire, the ice
loads and the wind pressures. The main difficulty arises from their
expansion and contraction caused by changes of temperature and ten-
sion. These and the wind pressures cause lateral and vertical curva-
ture of the contact wire. Both the deflections and the drop of tem-
perature increase its tension and produce at certain points large bend-
ing strains. To determine the degree of safety of the various sus-
pensions, the largest bending strains and tensions in the contact wire
and the ropes must l)e calculated. With regard to obstruction to the
view of the signals, 1h(^ fewer ropes, suspenders, posts, and bridges or
brackets, the better.
For judging the suspension suggested by Mr. Coombs by these
standards, and for finding whether it is sufficiently rigid to be suit-
able for use with a sliding bow that will run smoothly at high speed,
and sufficiently strong to resist with adequate safety the incident
forces, the size of the steel strand and the distance and nature of the
suspenders must be reasonably assumed, and the deflections and con-
sequent bending strains and tensions calculated.
Following Mr. Coombs' specification, a |--in. steel strand is ample,
and weighs 0.89 lb. per ft. of span. The 0000 copper wire weighs
0.64 lb., and gas-pipe suspenders, 12 ft, apart, about 0.33 lb., giving
a total weight of 1.86 lb. per ft. of span. Ice ^ in. thick on all parts
232 DISCUSSION ON OVERHEAD ELECTRIC TRACTION [Papers.
Mr. Mayer, weighs 1.63 lb., giving a total weight, with ice, of 3.49 lb. per ft. of
span. Taking the wire to consist approximately of two 0 wires
directly above each other, it is 0.65 in. high and half as wide. The
wind pressure on the bare metal of wire suspenders and strand, taking
12 lb. per sq. ft. all through, is 1.63 lb., and that on the ice-covered
structure, with 8 lb. per sq. ft., 2.57 lb. per ft. of span. Assuming a
tension of 1 000 lb. in the contact wire, the lateral deflection of the
wire, at maximum temperature, woi;ld be 3.15 ft. This assumes that
the wire is held at the ends of the spans by steady braces. If these
were absent, the lateral deflection would be much larger and thq
needed sliding bow would be altogether impracticable.
Where sliding bows are used, the wire must run alternately to the
right and left of the center line of track so as to distribute the wear
over a considerable length of the bow. Taking the lateral displace-
ment of the wire at the brackets to be 1 ft., and allowing i ft. for the
lateral vibration of the sliding bow, the latter must be 6.96 ft. long
to catch the wire, with the strongest winds assumed. A sliding bow
of this length, which will not jump at the suspenders, with moderate
train speeds, can be designed.
For the highest present steam railway speeds, a much larger ten-
sion in the contact wire or more frequent suspenders are needed to
prevent jumping and sparking, with the usual connection of the wire
to the suspender. Jumping and sparking might also be prevented by
a contrivance allowing the wire to rise at the suspenders, without
lifting them, when the sliding bow passes. With steady braces, which
are practically unavoidable with this design, the wire carries, at
maximum temperature, 0.49 lb. of the total wind pressure of 1.63 lb.
per ft., to the steady braces, and its tension is thereby increased.
Much more serious is the bending strain in the wire at the clamps
which connect it to the steady braces. These clamps may be designed
to avoid bending strain in the wire at maximum temperature without
wind. In this case, the lateral bending strain in the wire at the end
of the clamp, at highest temperature and wind pressure, is 35 300 lb.
per sq. in. For the wire here assumed, this bending strain is given
19 200 0 7i , • ^1 1 J- . • •
by the formula, s = 7- where s is the bending strain, m
V T
pounds per square inch, and T is the tension in the wire. If T is
decomposed into a component having the direction of the wire at the
end of the clamp and one normal to it, the horizontal component of
the latter is Q h, and the vertical component Q v. For the vertical
18 000 Q V
bending of the same wire, the formula is s = /- At the
V T
same time, with this bending strain of 35 300 lb. per sq. in., the tension
in the wire is 10 800 lb., giving a combined strain of 46 100 lb. per
sq. in.
Papers.] DISCUSSION ON OVERHEAD ELECTRIC TRACTION 333
The passing sliding bow increases the total strain to nearly 48 000 Mr. Mayer,
lb. per sq. in. The horizontal bending strain may be rediiced, theoreti-
cally, to one-half, by using two steady braces at each bracket and con-
necting them to the wire by hinged clamps, the hinges being vertical.
The steady braces themselves should have horizontal hinges permitting
the clamps to rise and fall with changes of temperature and wind
pressure and the passing of the sliding bow. By this rise and fall, the
principal vertical bending strains of the wire, except those due to the
passing bow, are transferred to the nearest suspender; therefore, they
need not be added to the horizontal bending strains occurring at the
steady braces. With hinged double steady braces, connected to the
wire by hinged clamps, the total strain per square inch at the highest
temperature, with the assumed wind pressure, is approximately 30 500
lb. This assumes that all the hinges work without friction. The fric-
tion of the hinges may increase this strain considerably. At the
lowest temperature, without ice, and with the largest wind pressure,
the lateral deflection of the wire is 15 ft., its tension is 5 000 lb., or
30 080 lb. per sq. in.
The bending strain at the steady braces due to horizontal bending
is 27 200 lb. per sq. in. with single, and half as much with double,
braces and hinged clamps. This gives combined strains of 57 280 and
43 680 lb. per sq. in. These strains are both increased about 1 000 lb.
by the passing sliding bow. Since they exceed the elastic limit, the
wire will bend before the strains reach the amount calculated. Re-
peated forward and backward bending will produce rupture. To re-
duce these large bending strains and tensions in the contact wire,
smaller deformations must be obtained. These can be secured by
smaller deflections of the carrying strand which requires either heavier
strands or shorter spans.
With a |-in. strand of 3 ft. maximum vertical deflection and 300
ft. span, carrying 6 in. below the strand at the center of the span a
0000 grooved wire which is horizontal and has 1 000 lb. tension
at the highest temperature, without wind, the deflections and strains
in the wire are as follows: At the highest temperature and wind
pressure, the horizontal deflection of the wire is 2.17 ft., its upward
deflection is 0.23 ft., the tension is 8 260 lb. per sq. in., the horizontal
bending strain is 20 580 lb. per sq. in. with single and half as much
with double steady braces. This gives, with the latter, a combined
strain of 18 550 lb., which is increased to about 20 600 lb. per sq. in.
by the passing sliding bow. This is a great improvement over the
corresponding 30 500 lb. with 6 ft. deflection of the strand.
At the lowest temperature, with the highest wind pressure, without
ice, the vertical deflection of the strand is 1.85 ft., its lateral deflec-
tion is 0.9 ft. The vertical upward deflection of the wire is 1.18 ft.
and its lateral deflection 1.05 ft. The tension in the wire is 4 760 lb..
234 DISCUSSION ON OVERHEAD ELECTRIC TRACTION [Papers.
Mr. Mayer, or 28 640 lb. per sq. in. ; the horizontal bending strain, with double
steady braces, is 9 290 lb., giving a combined strain of 37 930 lb. per
sq. in. This is increased to about 39 000 lb. by the passing sliding
bow. With hinged steady braces, most of the vertical bending strain,
amounting, if concentrated, to 24 800 lb. per sq. in., is transferred to
several of the nearby suspenders. If these suspenders have clamps at-
tached to them by horizontal hinges, allowing oscillation of the wire
in a vertical plane, then the vertical bending strains are certainly
smaller than the horizontal ones; if there are no such hinges, such
strains are probably larger than the horizontal bending strains with
double steady braces, but they cannot easily be calculated with ac-
curacy. With ice and wind, at the lowest temperature, the lateral
deflection of the wire is 1.48 ft., the upward deflection is 0.46 ft., its
tension is 4 760 lb. or 28 640 lb. per sq. in. The horizontal bending
strain, with double steady braces and hinged clamps, is 13 100 lb.,
giving a combined strain of 41 740 lb. per sq. in. This is increased
about 1 000 lb. by the passing bow.
The maximum tension in the strand is 16 200 lb., which gives a
factor of safety of 3, provided the small bending strains are neglected.
A sliding bow 5 ft. long is needed, and can be designed so as to give
smooth running at all but the highest speeds. It is evident that the
strains in the wire are still excessive where the wind pressures and
ice loads prescribed by the specification really occur. As these are of
rare occurrence, a structure of this design, with improved hinged
double steady braces, connected to the wire by hinged clamps, will
probably, in most situations, last a number of years. It would have
about the rigidity of a double catenary suspension of the same span
with two strands of A in. diameter and 6 ft. vertical deflection,
having the wire 6 in. below the lowest point of the strands. The
largest lateral deflection of the wire of this latter suspension, with the
wire tension and wind pressure here assumed, is approximately 2.25
ft. In the double catenary suspension, no steady braces are used, the
bending strains in the wire due to its vertical and lateral deflection
are distributed to several clamps near the ends of the spans. They
cannot easily be calculated with accuracy, but are probably somewhat
smaller than in the best single catenary suspension of the same span.
The tensions in the wire are nearly the same in both designs here
compared. The double catenary suspension is certainly superior in
strength to a single catenary suspension of the same span and lateral
deflection with single steady braces. All these designs are far in-
ferior in safety to railroad bridges.
Taking now a 0000 round wire, hung from special suspenders,
with 300-ft. spans and 4 ft. maximum vertical deflection, with strain
adjusters 1 mile apart, the adjusters changing the length of the
spans four times a year, so that the variation of temperature with one
Papers.] DISCUSSION ON OVERHEAD ELECTRIC TRACTION 235
length of span does not exceed 84° f ahr. : The largest lateral deflec- Mr. Mayer,
tion of the wire is 2.54 ft. A sliding bow 6 ft. long is required. The
tension in the wire at the lowest temperature, with wind and without
ice, is 3 260 lb. or 19 600 lb. per sq. in. The maximum bending strain
at the same time is 6 250 lb., giving a total strain of 25 850 lb. per
sq. in. The corresponding strain in the suspension suggested by Mr.
Coombs is 44 680 lb. per sq. in. In the single catenary suspension,
with 3 ft. maximum vertical deflection of the strand, it is 39 000 lb.
with the best design.
With a coating of ice, i in. thick on the contact wire, increasing its
diameter i in., the maximum tension at the lowest temperature, and
with a wind pressure of 8 lb. per sq. ft. of ice-covered wire, is 21 530
lb., the bending strain is 6 250 lb., giving a total of 27 780 lb. per sq.
in. A greater thickness of ice on the contact wire would make it
difBcult to collect the current. Where there is considerable traffic,
the wire will be generally several degrees warmer than the atmosphere,
and less ice will form on it than on steel strands carrying but little
current, and the passing sliding bow will kneck off much of that
which forms. It is reasonable, therefore, to assume a smaller amount
of ice on the contact wire than on the strands. The maximum strain
in the wire, with ice i in. thick, and a wind pressure of 8 lb. per sq.
ft., at the lowest temperature, in the best of the single catenary suspen-
sions of the same span is 42 700 lb. per sq. in. ; this would be but
little reduced by assuming the ice on the contact wire i in. thick, the
strain without any ice being 39 000 lb.
The strandless suspension here described requires, for smooth run-
ning with a speed of 70 miles per hour, a sliding bow of 4 lb. equiva-
lent weight, 6 ft. long. Such a bow can easily be designed, but, as
far as the speaker is aware, it is not at present in the American mar-
ket. The bows in use are designed for smaller speeds. If they are to
be used with high speeds, shorter spans are necessary. The 4-ft. de-
flection of the contact wire requires a larger range of vertical motion
of the bow than the catenary suspension of the same span, in which
the height of the wire varies only about 2 ft. Though 300-ft. spans
are entirely practicable and safe, with improved strandless suspension
and a speed of 70 miles per hour, they will riot give continuous con-
tact at this speed without improved sliding bows.
The speaker has invented another suspender, which can be used
at any speed with ordinary sliding bows of large equivalent weight,
and reduces still further the bending strains. With it, 300-ft. spans
can be safely used. As the sliding bow may be heavy, it may be made
longer, and a maximum vertitial deflection of 4J or 5 ft. may be
adopted, thus reducing greatly its maximum tension. This suspender
will be described later.
The calculation showing the excessive bending strains in the
236 DISCUSSION ON OVERHEAD ELECTRIC TRACTION [Papers.
Mr. Mayer, single catenary sv;spensions of 300-ft. span is confirmed by practical
experience with long-span electric transmission lines. In these, solid
wires were first used, but they broke at the insulators even with
moderate tension per square inch. Stranded M'ires, therefore, are
now used with long spans. Many experiments have been made with
single catenary suspensions. As a result, the present practice in
America and in Europe, as far as known to the speaker, does not
show any existing spans of more than 160 ft. The importance of re-
ducing the lateral and vertical deflection of the contact wire, and
thereby its bending strains, is fully appreciated by the designers of
most, if not all, of the existing structures in America. The sliding
bows are generally 4 ft. long, and could not be used with large lateral
deflections.
Taking a design with 150-ft. spans of a steel strand of ^^ in. diam-
eter, with 16 in. maximum vertical deflection, the 0000 grooved
wire being horizontal at the highest temperature and 4 in. below the
strand at the center of the span, the following deflections and strains
are obtained with a variation of temperature of 140° fahr., and the
loads and wind pressures mentioned by Mr. Coombs : The weight of
wire, strand and suspenders is approximately 1.04 lb. per ft., the wind
pressure, without ice, is 1.15 lb. per ft. The weight, with ice, is 2.33
lb., and the wind pressure is 2.10 lb. per ft. With the greatest wind
pressure, and at the highest temperature, the lateral deflection of the
wire is approximately 0.95 ft., its tension is 1 284 lb., or 7 730 lb. per
sq. in., the horizontal bending strain, with ordinary steady braces, is
17 410 lb., giving a combined strain of 25 140 lb. per sq. in. ; this is
increased to about 27 100 lb. by the passing of an improved sliding
bow of a maximum dynamic pressure of 25 lb.
At the lowest temperature, with the greatest wind pressure, and
without ice, the upward deflection of the wire is approximately 0.3 ft.,
the horizontal deflection is 0.38 ft., its tension is 4 640 lb., or 27 920
lb. per sq. in. The horizontal bending strain is 6 630 lb., giving a
combined strain of 34 550 lb. per sq. in. This is increased to about
35 500 lb. by the passing sliding bow. If the wire is firmly held at
the steady brace, so that it cannot rise and fall, the combined strain
due to tension and horizontal and vertical bending is about 40 000 lb.
With ice having an average thickness of i in., at lowest tempera-
ture and with the greatest wind pressure, the wire has a lateral deflec-
tion of 0.6 ft. and a downward deflection of 0.07 ft. Its tension is 28 160
lb., and the horizontal bending strain is 10 510 lb., giving a combined
strain of 38 670 lb. per sq. in. This is increased by about 1 000 lb.
per sq. in. by the passing sliding bow.* The horizontal bending strain
may be reduced to one-half and the vertical bending strain transferred,
by a perfect double steady brace, allowing the wire to rise and fall
and turn.
Papors.] DISCUSSION ON OVERHEAD ELECTRIC TRACTION 237
Wire havino- an elastic limit of 40 000 lb. per sq. in. can be ob- Mr. Mayer,
tained, and. with little ice and moderate wind pressures and changes
of temperature, jjives an approximately safe structure with the usual
designs.
The maximum tension in the steel strand, with the foregoing
loads, is 5 000 lb., the ultimate strength of a cast-steel strand is about
13 600 lb.
These results explain why much longer spans are not used with
single catenary suspension.
It is evident that a structure having the factor of safety of a
railroad bridge is not practicable with ordinary catenary suspension,
in most climates. If Mr. -Coombs' description of the Siemens-Schuc-
kert suspension is correct, and if the pulleys over which the con-
tact wire is carried have a diameter of 12 ft., larger pulleys being
impracticable, the bending strain in the wire here assumed would be
36 000 lb. per sq. in. If the tension in the contact wire is made small,
the lateral deflection of the wire would be much increased, and long
spans with large strand deflection would be impracticable. This sus-
pension is used with spans of 48 m., with a steel carrying structure
where long spans are very desirable. If the designers had thought
them practicable, they would probably have adopted them. Spans of
300 ft., with single catenary suspension, therefore, are not sustained
by precedent; they cannot be defended successfully by theory, and
they will probably prove short-lived if tried under conditions ap-
proximating those here assumed.
The maximum strains which demonstrably exist in the contact
wires with catenary suspension show what a copper wire can stand, at
least for a few years. They make it extremely probable that a wire in
which the maximum strain never and nowhere exceeds 30 000 lb. per
sq. in. is abundantly safe.
W. K. Archbold, Esq. — Regarding the matter of protective struc- Mr. Archbold.
tures where transmission lines cross railroad tracks, Mr. Coomb's
paper should help to standardize the practice, which has varied ex-
tremely, as the speaker has had occasion to note. Under the direction
of Thomas H. Mather, M. Am. Soc. C. E., an overhead construction
has recently been designed and installed on the line of the Syracuse,
Lake Shore and Northern Railroad, running from Syracuse to
Baldwinsville, N. Y. The line is about 5 miles long, and is provided
with single-catenary trolley construction presenting some new features,
Mr. Mather thinks that the work has not yet advanced far enough
to warrant the presentation of a formal paper, and therefore the
speaker will make simply a preliminary presentation of the prominent
features of the construction.
The trolley wire is hung from a messenger cable supported on
bridges spaced 300 ft. apart, from center to center. The bridges, as
238 DISCUSSION ON OVERHEAD ELECTRIC TRACTION [Papers.
Mr. Archboid. shown ill Plate XXXIV, consist of light trusses on bents 30 ft. apart,
from center to center. The bents are each composed of two 8-in. chan-
nels, 6 ft. apart at the base, converging to 8 in. at the top, and sup-
ported on concrete pedestals, 20 in. square, and of depth varying with
the nature of the ground. The trusses have an 8-in. channel top chord
and 6-in. channel bottom chords, set with the flanges down. The
diagonal members are g-in. rods, and the struts 2J by 2J by i-in.
angles. The struts are flattened and bent over at the ends, and are
riveted to the channels.
To the top chord of each truss are bolted malleable-iron pins to
v/hich are cemented porcelain insulators for the messenger cable. The
three-phase high-tension line is supported on steel A-frames at each
end of each bridge. The construction is designed for a wind pressure
of 8 lb. per sq. ft. on the trolley and messenger cables, covered with
i in. of ice, a somewhat lower ice load being assumed on the high-
tension cables, which are of No. 2 copper. The structure is computed
as a braced portal, the unit strains under the assumed wind and ice
load being 22 500 lb. per sq. in., reduced for compression members.
The catenary is strung for a net sag of 6.5 ft. at 100° fahr. At 20°
fahr., the sag is about 6.5 ft., and the trolley is about 1 ft. higher at
the center of the span than under the bridges, the height from rail to
trolley being 18 ft. at the bridges. Stranded steel messenger, 15 000-lb.
wire, y^ in. in diameter, supports steel hangers, | in. in diameter,
spaced 10 ft. apart, from center to center. These hangers are of the
Ohio Brass Company type, and are attached to the messenger cable
with a sister hook through the base of which the rod is threaded and
drawn up tight against the messenger cable. The 0000 grooved
trolley is secured to the hanger by Detroit clamps.
At each bridge there is a span-wire steady strain (not shown in the
photograph), the trolleys being insulated from the bridge and from
each other by 6-in. wheel-type porcelain strain insulators. The messen-
ger cable is dead-ended on an equalizer attached to a pair of these in-
sulators, which are connected by short cable loops to a similar pair
secured to the anchor bridge.
A test which came on the line during construction showed the
effect of a broken messenger wire. When about half a mile of wire
had been pulled up, and hangers were on three or four of the spans,
the dead-end arrangement broke, allowing the line to go. The insu-
* lator broke on the bridge next to the dead-end bridge, but the trouble
did not extend any further than that point. Some of the men on the
work thought the foundation of the second bridge was raised a little,
but there seems to be considerable difference of opinion on that point,
and certainly no damage was done. The idea has been that the bridges
would be what might be called semi-anchored; or, in other words, the
effect of a break would not go beyond two or three bridges in either
PLATE XXXIV.
PAPERS, AM. SOC. C. E
MARCH, 1908.
ARCHBOLD ON
OVERHEAD CONSTRUCTION
FOR ELECTRIC TRACTION.
Papers.] DISCUSSION ON OVERHEAD ELECTRIC TRACTION 239
direction. It is possible, too, that the heavy rods and tight clamping Mr. Archboid.
effect, obtained both at the messenger and trolley wires, assisted con-
siderably in holding the line. At any rate, no damage was done which
could not be repaired quickly.
The high-tension wire is strung with a sag of 40 in. at 20° fahr.,
and has a net clearance of about 24 ft. from the track. As the trolley
may at some time be operated at 6 600 volts, single-phase, all the in-
sulation of the catenary, steady strains, etc., is designed to withstand
this voltage. At present, however, it is being operated at 600 volts,
direct-current. In regard to the lateral stiffness of the single catenary
with supports 300 ft. apart, it may be noted that the line has been in
operation about 10 days, and, thus far, very little deflection or rolling-
can be observed under the action of the wheel trolley with a tension of
about 25 lb. During this time there have been temperature changes
of 50° and wind velocities of 45 miles per hour. These conditions
seemed to make no difference in the operation, even before the steady
strains were installed.
The speaker feels justified in saying positively that, with this type
of construction, there will be no difficulty from side-sway on the 300-ft.
span. It is yet to be determined whether the line is too stiff in the
vertical plane, but that cannot be determined positively except by
operation extending over a considerable period, and including hot as
well as cold weather. The preliminary tests which have been made in-
dicate that there will be no difficulty.
This line is a re-location, to shorten the running time and provide
a double track on private right of way between Syracuse and Baldwins-
ville. The old single-track line is on a highway, and is about | mile
longer than the new location, which will form part of a new high-speed
electric road between Syracuse, Fulton, and Oswego, a total distance
of about 35 miles.
Charles Eufus Harte, M. Am. Soc. C. E. — In the field of trans- Mr. Harte.
mission- and distribution-line construction, each engineer lias been
largely a law unto himself, and Mr. Coombs' effort to secure some
measure of standardization is much to be commended. At the same
time, local conditions very largely govern, and the successful construc-
tion of one locality may be of little value even in comparatively near
sections.
In addition to the causes given by the author, a short circuit may
be caused by the swaying together of two phases of the circuit. This,
however, may be prevented by spacing the wires a distance apart equal
to at least twice the versed sine of the sag. Thus the Missouri River
transmission has a spacing of 78 in. ; the 1 450-f t. Connecticut River
span of the Springfield-Suffield Line, 84 in.; while the Madison River
Line, of Montana, has 108 in. As an additional precaution, the wires
are often arranged so that no two are in the same horizontal plane.
240 DISCUSSION ON OVERHEAD ELECTRIC TRACTION [Papers.
Mr. Harte. This is characteristic of the Connecticut Eiver span, the Anglo-
Mexican, the Southern Power, and many other transmission lines.
The large spacing (of the triangle), with two wires in a vertical plane,
also materially reduces the likelihood of interference from large birds,
or branches or wires blown against the line. In practice, however, be-
cause of their weight and low periodicity, long spans usually swing
in unison, thus maintaining the spacings.
Mr. Coombs states that insulator troubles are largely due to mis-
directed savings. While it is true that there are to-day many lines
operating without change at higher voltages than designed for, and
on which the insulators were poor for the original voltage, there are
many other lines where, although no expense has been spared, insulator
troubles are very serious.
On the seacoast, particularly in Southern California, heavy salt
fogs cause troubles which, as far as the speaker knows, have not yet
been overcome successfully; in the alkali deserts, the so-called salt
storms result in losses by very remarkable brush discharges and leak-
ages; and where lines are near steam-railroad right of way the oil and
water from the exhaust condense on the insulators and then collect
coal and other dust until the creeping surface is largely covered, caus-
ing heavy leakage, and burning wooden pins. This condition promises
to be a very serious problem in steam-road partial electrification. The
deposits from salt and dust storms are washed off by the rains, but the
oily coating resulting from locomotive exhausts is not affected by
water.
While a "campaign of education" may be of assistance, the small
boy with his sling-shot and the man with the gun will always menace
seriously the welfare of insulators in settled sections. Dark-colored
glazes, being less conspicuous, are being used in many cases. With
medium voltages, compact insulators of the Eedlands or Crown type
are iised, and one large manufacturing company grooves the insulator
top, with the idea that the marksman will knock out the portion inside
the groove and then retire satisfied, leaving enough insulator on the
pin to protect the line. As a matter of fact, against a bullet of any
weight there is little choice as to type. The speaker tested the three
38
types shown, Fig. 1. Plate XXXV, using a Winchester r-rT,-caliber
rifle, reproducing line conditions as far as possible, and firing one shot
at each. Pig. 2, Plate XXXV, shows the result. In New England
or the East generally, a gun of such heavy caliber would rarely, if ever,
be used.
Serious sleet storms, fortunately, are not common, and are rarely
of great extent. While failure may be due to the dead weight of the
accumulation, the usual cause is more complex. In a strong wind, the
sleeted wires, because of the greatly increased area and weight, sway
PLATE XXXV.
PAPERS, AM. SOC. C. E.
MARCH, 1908.
HARTE ON
OVERHEAD CONSTRUCTION
FOR ELECTRIC TRACTION.
Fig. 1.— Insulators, Before the Test.
Fig. 3.— Insulators, After the Test.
Papers.] DISCUSSION ON OVERHEAD ELECTRIC TRACTION 241
until the vibrations become synchronous with the natural period of a ^r. Hartt
pole of the line. If this pole fails, the resulting long span usually has
weight enough to pull down other poles on each side.
Aluminum does not appear to hold sleet as does copper, and lines
transmitting much power are usually a little warmer than the air, so
that they throw oft" the coat quickly, therefore, an allowance of i in.
of ice around the wire is sufficient to provide for all reasonable con-
tingencies. The sleet coatings, however, may become very heavy. Fig.
1, Plate XXXVr, shows an accretion of clear ice on a twig, the coat-
ing having a diameter of practically 3 in. ; and C. J. H. Woodbury,
M. Am. Soc. C. E., recently advised the speaker of specimens he had
seen, one from Wayland, Mass., 4J in. in diameter, and one from
Nahant, 8 in. in diameter. Fig. 2, Plate XXXVI, shows the accumu-
lation on wires caused by the same storm which developed the twig
coating. This was at Winsted, Conn., on February 21st, 1898.
Occasionally, sleet and snow storms make trouble by bridging over
the creeping surface of the insulator, thus causing leakage to the cross-
arm. This, however, can be prevented by designing the pins and cross-
arms so as to leave no large catchment area, and by maintaining a con-
siderable distance from the insulator top to the arm.
The pressure variations in wind storms, cited by Mr. Coombs as a
reason for using a low value, are more properly reasons for introduc-
ing a sway factor. A field of grain or long grass, or ivy on a house,
observed in a wind storm, shows very clearly the successive pressure
waves. On a transmission line, when such impulses are synchronous
with the natural period of one of the poles, stresses are set up in the
latter far in excess of those due to the direct forces themselves. In
wooden pole lines there are stress transfers, due to the elasticity of
the poles and the slipping of the wires at the insulators, which relieve
these unusual conditions ; in tower lines, the greater rigidity of con-
struction largely prevents such relief, and the action miTst be con-
sidered in designing.
Mr. Coombs gives a series of very valuable tables of wire factors,
but there is a matter in connection with solid copper that, as far as
the speaker is aware, has been given practically no attention by any
investigator. The standard American copper-wire bar weighs approxi-
mately 200 lb. This is rolled to a rod of diameter depending on the
gauge of the wire it is to make. For 0000 trolley, this rod is about
560 mils in diameter, and is less than 300 ft. long. To secure the long
commercial lengths of trolley, the rods are brazed together, the scarf
having an angle of about 20°, the brazing being done with a mixture
of silver and tin at a temperature near 800° fahr. As a result, the rod
is annealed at the scarf, and the subsequent drawings to a diameter of
460 mils do not harden this annealed portion.
From tests of brazes, it appears that their strength is only eight-
242
DISCUSSION ON OVERHEAD ELECTRIC TRACTION [Papers.
Mr. Harte. tenths of that of stock wire. Incidentally, it should be noted that the
strength of grooved 0000 wire is from 4 to 5% lower than that of
round wire, due to the fact that more work is done upon the latter.
Grooved wire cannot be given a second reduction after the groove has
been made.
TABLE 11.— Tests of 0000 Grooved Trolley Wire.
Length tested in each case, 10 in.
Tests of Brazed Joints.
to M
fl
s
p
CO
<D
•s-g
"S.S
c3 .
^ CI
siS.S
Cm
W 5
h^
m
3 639
0.475
1.4
5 852
1.5
3 630
0.476
1.5
6 306
6.7
3 631
0.448
0.9
4 429
14.7
3 632
0.475
1.4
6 175
6.5
3 633
0.452
1.1
i 515
13.9
3 634
0.476
1.3
6 390
3.8
Average.
0.467
1.3
5 611
7.9
Remarks.
j Apparently good braze. Broke in joint, with par-
1 tial separation of braze.
Apparently erood braze Broke outside joint.
\ Apparently good braze. Metal reduced in section
-: by ttlirig. Broke in joint, with partial separa-
( tion of copper.
Apparently good braze, broke outside joint.
^ Apparently poor braze. Metal reduced in section
by filing. Broke in joint, with partial separa-
( tion of copper.
( Apparently good braze. Broke in joint. Separa-
tion very slight. Flaw in copper at point of
( rupture.
Tests of Wire From Sections Between Joints.
3 628
0.478
7 087
7.0
3 635
0.478
7 085
5.7
3 636
0.478
7 166
5.4
3 637
0.478
7 077
8.3
3 638
0.478
....
7 076
5.9
Average.
0.478
7 098
6.5
Fracture silky, angular.
The failure at a braze does not occur in the braze itself, but in the
area immediately adjoining; the break is usually parallel to the scarf,
but there is invariably a skin of copper on the braze.
At least one wire manufacturer uses a specially heavy wire bar
when requested, thus having fewer brazes per mile, but, in any case,
it is the braze which determines the strength of the line. For this
reason, as well as because of its flexibility and consequent ease of
handling, stranded copper is much better than solid for transmission-
PLATE XXXVI.
PAPERS, AM. SOC. C. E.
MARCH, 1908.
HARTE ON
OVERHEAD CONSTRUCTION
FOR ELECTRIC TRACTION.
Fig. 1.— Sleet Accretion on Twig, Winsted, Conn., February 31st 1898.
1 A/
,:?^i^^ '
Fig. 2.— Sleet Accretion on Wires. Winsted, Conn., February 31st, 1898.
Papers.] DISCUSSION ON OVEEHEAD ELECTRIC TRACTION 243
line work, the strand brazes being distributed along the made-up cable. Mr. Harte.
It should be added that the problem of the braze is now occupying the
attention of a number of the large wire manufacturers, and it is hoped
that decided improvements will follow.
Mr. Coombs refers to a grooved trolley wire having an area of
0.155 sq. in. and an ultimate strength of 8 800 lb. The speaker would
like to have further details of this wire. Commercial, American, 0000,
grooved wire, having a cross-section of 0.167 sq. in., this being a little
more than 7% greater than the wire referred to, in a series of tests,
failed to reach an ultimate strength of 8 000 lb., the break usually
occurring at about 7 800 lb.
Mr. Coombs' type of anchor is good for comparatively light
stresses, but for heavy spans it is desirable to arrange the insulators in
pairs, or, if in tandem, to the catenary of the span, to secure uniform
stress distribution.
Where the sag must not fall below fixed limits, provision must be
made for adjustments of considerable extent. In Mr. Coombs' design,
any considerable take-up on the turn-buckles would result in slack on
the saddle, not readily cared for. This may be avoided by using a
double saddle, both parts being movable, the slack looping between.
The Connecticut River crossing of the Springfield-Suffield line has a
crossing span attached to a movable cross-head controlled by a long
screw with an adjusting nut. Fig. 9. The main line taps into the
crossing span at the cross-head, and has a "pigtail" to care for the
variation in length.
Under specifications, to bar thin wiped galvanizing, it is desirable
tc require the galvanized metal to stand four immersions, of 60 sec.
each, in a saturated solution of copper sulphate, at 70° fahr. After
each immersion the test piece should be dipped into clean water and
then wiped dry; no metallic copper should appear after the fourth
immersion.
The speaker wishes Mr. Coombs had treated the subject of protec-
tion of line crossings at greater length. Apparently, the crossing de-
scribed is protected, over and above the general line, only by taking
additional precautions to relieve the crossing towers from stresses due
to adjoining spans, and in certain details of anchorage of line, provi-
sion being made for the installation of a cradle at a later date if
desired.
As far as line strength is concerned^ a crossing differs from a normal
span only in possible greater length, or in restrictions as to height of
wire; and a failure at this point, in its effect on the service, does not
differ from a failure elsewhere; but, in the possibilities of damage to
train, to passengers or others on platforms or highways, or to other
lines, the crossing becomes one of the most critical line points, and
the method of safeguarding it is of the utmost importance.
244 DISCUSSION ON OVERHEAD ELECTRIC TRACTION [Papers.
Mr. Harte. Protection may be effected by :
1. — Mechanically preventing a broken wire from getting into
the danger section;
2. — Strengthening the upper wires so that failure is practically
impossible;
3.- — Grounded arms to cut ofi a broken wire at the pole top be-
fore it can reach the line below.
Of the first class are the various cradles, all open to the criticism
that they offer large areas for sleet lodgment, and most of them that
they are very expensive.
A very simple type consists of telegraph wires strung between mul-
tiple pin arms. The system is grounded, but the small section of the
wires is usually a guaranty that they would be burned through by the
arc in case of a fall of the power line. Fig. 1, Plate XXXVII.
A modification consists of three longitudinal wires with cross-bars
of hard wood; other variations include sheets of wire netting, net-
works of wire strand more or less substantially fastened together, up
to the very impressive cradles of heavy strand with cross-bars of flat
iron. As clearly appears in the case shown. Fig. 1, Plate XXXVIIl,
wood bar cradles are apt to lose members from breakage or otherwise,
while the heavier wire cradles often sag, becoming a positive menace-
In Fig. 2, Plate XXXVII, is shown a wire-strand cradle which has
sagged to an extent requiring the power company to protect its lines
by the support wires strung on the top arm of the transmission line.
While the more substantial types, if large enough to keep a fallen
wire from blowing out again, are no doubt efficient along certain lines,
their great cost, and the excessive stress imposed by them upon their
supports, even without the great loads of sleet they are sure to catch,
make them very undesirable.
The ideal protection is the so-called short-span method. Here the
crossing span and the two spans adjoining are arranged so that the
distance apart of the poles is less than the distance from the cross-arm
of the upper line to the lower line; it is thus impossible for the two
lines to touch, under any circumstances, while the adjoining short spans
prevent a broken wire from swinging into the crossing-span section.
Unfortunately, crossings usually occur in highways where limitations
as to pole locations prevent the use of this method.
The method most generally applicable, and, in the speaker's judg-
ment, the best, is that of reinforcing the line by a set of messenger
cables. This plan has the great advantage that the line is locally
doubled in strength, with but little increase in weight or in exposure
area, and the cost is nominal.
In a recent and satisfactory design, messengers of No. 2 stranded
copper are used, and to them the line wire is tied every 4 ft. A
PLATE XXXVII.
PAPERS, AM. SOC. C. E.
MARCH, 1908.
HARTE ON
OVERHEAD CONSTRUCTION
FOR ELECTRIC TRACTION.
Fig. ].— Wire Gridiron Under 33 000- Volt Transmission Line.
Fig. 2.— Wire Cradle Over 11 oOO-Volt Transmission Line
Papers.] DISCUSSION ON OVERHEAD ELECTRIC TRACTION 245
Mr. Harte.
346 DISCUSSION" ON OVERHEAD ELECTRIC TRACTION [Papers.
Mr. Harte. grounded angle-iron frame just beneath the line provides an automatic
cut-o£F in case the line breaks in the span adjoining the protected span.
Fig. 10, and Fig. 2, Plate XXXVIII.
A protection device should meet the following requirements:
1. — Complete protection of the lower line^ including protection
from a failure in an adjoining span with wires whipping
into the protected section;
2. — A minimum of areas exposed to sleet or wind;
3. — Little increase over weight of normal line;
4. — Simplicity of design;
5. — Construction familiar to linemen;
6. — Few special parts;
7. — Low cost of installation and maintenance.
The foregoing types of protection assume that the power line is
above, and the additional safety of such arrangement will usually
justify a considerable expenditure to secure it. In some cases, how-
ever, it is practically impossible to go above with the transmission line.
In such cases the method of the American Telephone and Telegraph
Company, of practically enclosing the upper line in a sheath of |-in.
strand network is the best, provided the design is such that it will
prevent dangerous sagging of the cradle.
In any cradle design, the tendency of a broken wire to curl and
therefore jump out of the cradle should be recognized ; in Germany and
Switzerland it is customary to compel transmission companies to make
all lines crossing railroads pass through a regular tunnel of ironwork.
Where the line is on very narrow right of way, and where it carries
trolley brackets, straight poles are essential, and it is often desirable
to use selected stock in important highways, but in the majority of
cases considerable crook can be allowed. Certainly, where chestnut
is to be used, Mr. Coombs' requirement of only 1 in. of crook in 10 ft.
of length is unnecessarily rigid.
Tbe Western Lumberman's and the Idaho Cedarmen's Associations
have defined commercially straight cedar poles as having a crook in
one direction only, and a sweep not to exceed 1 in. in 6 ft. For chest-
nut, the American Telephone and Telegraph Company allows practi-
cally 1 in. sweep in 24 ft. of length for poles up to 40 ft. total length,
and of 1 in, sweep in 3 ft. for poles more than 40 ft. in total length,
the measurements to be made between the top and a point 6 ft. from the
butt.
Chestnut from seed often grows very straight; stump-grown stock,
which to-day forms a large proportion of the supply, almost in-
variably shows a sharp crook near the butt, due to the growth of the
shoots, first out to clear each other and then straight upward. If
this crook is large, it increases the cost of pole setting, but a diver-
Papers.] DISCUSSION ON OVERHEAD ELECTRIC TRACTION
24'^
Mr. Harte.
248 DISCUSSION ON OVERHEAD ELECTRIC TRACTION [Papers.
Mr. Harte. gence from the general axis of the pole of not more than 12 in. in the
lower 6 ft. can be cared for without additional work.
In the speaker's judgment, the severity of the specification does not
increase the line strength, and, as it materially increases the cost, it
would seem that it might better be changed, to meet current practice
and market limitations, to the following:
Cedar poles shall have but one crook, this in one way only, the
sweep not to exceed 1 in. in 6 ft.
Chestnut poles shall have but one crook, this in one way only.
The sweep shall not exceed the following limits between butt and top:
Pole length, in feet: 30—35—40—45—50—55—60—65—70.
Sweep, in inches: 9— 10— 11— 11— 11— 12— 13— 14— 15.
As far as the speaker is aware, there has as yet. been no wreck of
any magnitude on any of the electrified steam lines, and, until such a
try-out, certain questions of design must remain imanswered.
It is not at all unlikely, however, that, at least for lines on which
freight trains, with their capacity for trouble, are handled; the ulti-
mate development in steam railroad electrification will be in the di-
rection of independent overhead lines for each track or group of tracks.
With one live trolley, emergency movements can be made on ad-
joining tracks; with all overhead wires down, as may well be feared
in a wreck under bridge construction, not only is the electrical equip-
ment helpless, but a large additional burden of clearing away the ma-
terial devolves on the wrecker.
Whatever the design, the speaker feels that the unit stresses allowed
by Mr. Coombs are too high. With long and frequent trains, and par-
ticularly with high voltages, the failure of any part of the overhead
system offers too great an opportunity for serious results to justify
any close paring in the design.
Steam railroad electrification for some years to come will be un-
dertaken only where there is in sight a very marked gain by the
change, or where legislation compels it. The complications with which
the simplest distribution system involves maintenance operations, and
the awkward fact that for wrecking, and in ''dead" sections, some self-
contained motor must be used, weigh heavily with men familiar with
steam-road operation, and offset many of the obvious advantages of
electrification. It will rarely happen that a cost variation several times
in excess of the difference between thoroughly dependable construction
and "probably safe" construction will be of weight in influencing the
decision, and in the few cases where it is a factor it is far better for
the art that the work be deferred rather than incur an unjust discredit
because of failure, either physical or in performance, as to expected
maintenance and operation costs.
Whatever the unit stresses, the bridges, brackets, or poles shouM
PLATE XXXVIII.
PAPERS, AM. SOC. C. E.
MARCH, 1908.
HARTE ON
OVERHEAD CONSTRUCTION
FOR ELECTRIC TRACTION
Papers.] DISCUSSION ON OVERHEAD ELECTRIC TRACTION 249
have a safety factor considerably in excess of that of the overhead Mr. Harte.
system proper, and messengers, hangers, and trolley should mark a
regiilarly descending scale, in order that any failure may be of the
least extent possible.
While it is trvie that the ordinary trolley suspension gives a catenary
curve, the general practice to-day is to apply the term "'catenary con-
struction" to systems supporting the trolley from one or more messen-
gers. Following this practice, overhead systems wouW be classified as:
1. — Simple Suspension. — Trolley carried by hangers directly
connected to span wire, bracket, or bridge;
2.— Catenary Suspension. — Trolley hung from one or more
messenger cables in turn carried by the span wires,
brackets, or bridges;
3.- — Single Catenary. — Having but one main messenger (as in
the Erie Railroad electriiication) ;
4.^Multiple Catenary. — Having more than one main messen-
ger (as in the New Haven electrification) ;
5. — Simple Catenary.- — Trolley carried directly by main messen-
ger; may be simple or multiple (as in the Erie or New
Haven electrification) ;
6.— Compound Catenary.— Trolley carried by a secondary
messenger system, in turn carried by the main messenger
(as in the Blankenese-Ohlsdorf Railway).
The kind of conductors best adapted to the collection of the power
is an open question. The two chief difficulties, with high speeds, are
the chattering of the shoe, due to alternate hard and soft spots in the
line, and the pressure variations, due to the great vertical range re-
quired of the pantograph.
The first problem may be solved either by floating or by fixing the
trolley wire; for undoubtedly a perfectly flexible line or one perfectly
rigid would give excellent results as far as it alone was concerned.
Whether the shoe will not chatter on the rigid line, as a result of the
irregular movements of the car, remains to be seen. It is interesting
to note that Mr. W. S. Murray, Electrical Engineer of the New York,
New Haven, and Hartford Railroad, in discussing his recent paper
before the American Institute of Electrical Engineers, is quoted* as
saying that, in his judgment, either the shoe or the line must be
flexible.
The second problem is largely a function of overhead crossing
limitations, and, to a large degree, is independent of the overhead
construction; therefore it must be cared for in the design of the col-
lector itself.
Both problems are of the field rather than of the office. Mr. Mayerf
* street Ruilicay Journal. January 18th, 1908, page 8i.
t Proceedings, Am. Soc. C. E., for December. 1907.
250 DISCUSSION" OK OVERHEAD ELECTRIC TRACTION" [Papers.
Mr. Harte. has given a very elegant mathematical analysis of shoe pressure under
certain conditions, but the discussion is based on the supposition that
the car end of the collector traverses a path bearing a definite and
regular relation to the conductor. As a matter of fact, however, this
path is most irregular. Unevenness of track, as to grade and line,
gauge variations of rail and wheel, side play in axle boxes, spring
action, and movements in the car framing itself, all affect the shoe
pressure entirely independently of the variations due to the collector
mechanism and the character of the overhead system.
Mr. Coombs recites five objections to the double, as compared with
the single, catenary. That the double catenary has greater first cost
and greater mass overhead is true, although, by the time the single
form has been properly secured by pull-offs, guys, and steady braces,
there is a surprising amount of material in the air.
As to maintenance, however, the speaker doubts whether a single
catenary is not at least as troublesome. A double catenary can stand
severe punishment and still permit the movement of trains. On the
other hand, the hangers of the single catenary are more out of the way,
and therefore less likely to be injured.
Either type requires the tower car for repairs, but the double
catenary has twice as many connections to make; on the other hand,
its greater strength and rigidity undoubtedly reduce the troubles above
the trolley.
That the double catenary offers greater obstruction to the view of
the signals, the speaker cannot admit. If the signals are on bridges,
they will be between the tracks, and a curve that would bring the
overhead structure across the line of sight would also bring the pole,
towers, or truss posts also into line. The difficulty relates to the sec-
ondary supports rather than to the type of suspension.
Mr. Coombs sums up the situation admirably. If anything remains
to be said, it is this : In the present state of the art there is a great
lack of, and need for, data resulting from practical tests of the various
theories.
In closing, the speaker wishes to express his obligations to the many
friends who have kindly assisted in the experiments, and have loaned
illustrations for use in this discussion.
Mr. Osgood. Farley Osgood, Esq. (by letter). — If the high-tension wires are of
sufficient mechanical streng-th to have a factor of safety of 3, under
correctly-assumed general conditions, it is very doubtful if a con-
ductor will part in the span.
Up to crossings of 600 ft., it is not considered that the wires are
likely to cross in high winds, even though spreaders are not used, as
experience seems to indicate that the wires will swing from their normal
positions about equally.
Protection, in the form of lightning rods, seems desirable at cross-
Papers.] DISCUSSION ON OVERHEAD ELECTRIC TRACTION 251
ings where very high wooden towers are used, or on lower wooden cross- Mr. Osgoori.
ings at points of high altitude.
If steel towers are used at railroad crossings, the use of lightning
rods is desirable, if the crossings are at such points in the line as are
known to he affected by lightning disturbance.
The use of cradles, suspended from high-tension poles, under the
high-tension wires, is not advocated by the writer, for any ordinary
circumstances.
An ideal high-tension crossing would have the supporting towers of
sufficient height to make it impossible for one of the transmission wires
to touch the ground in case it should break in the crossing span, but
this condition is usually impossible, from a rational standpoint, owing
to the length of the section.
A second choice for crossings seems to favor a supporting tower at
the edge of the railroad company's right of way, and another between
the telegraph or signal wires and the outside rail, thus using four poles
or towers to a crossing, making a short span on each side of the tracks
over the telegraph or signal wires and the longer span over the tracks,
it being assumed that the railroad company has wires to be protected
on each side of its tracks.
These poles should be of sufficient height to prevent one of the
high-tension conductors from touching the telegraph or signal wires,
if it should break, so that, if a high-tension conductor should give way
over the tracks, the signaling system would not be affected, although
this might not always be true if any of the rails were used as part of
the signaling circuit.
If railroad companies feel that screens or cradles should be placed
under high-tension wires, let such devices be placed in the top arm
positions on the poles carrying the telegraph or signal wires, as their
purpose can then be accomplished and no unnecessary burden be placed
on the more important high-tension towers.
A simple and inexpensive type of screen, if used as suggested, can
be made up as follows: In the top e?in cf the pole on each side of the
high-tension crossing, place a ten-pin cross-arm, somewhat longer than
the standard cross-arm used on the line to be protected, and run in
between these arms, ten No.. 6 or No. 8 galvanized steel wires, strapped
together, and grounded at each pole.
W. S. Murray, Esq.^ (by letter). — Mr. Coombs has handled this very Mr. Murray,
interesting subject in an analytical and conservative manner. With
reference to that part of his paper concerning the strength of the ma-
terials to be used for wires and supporting structures, the basis of his
assumptions could not be better founded than on the records given in
liis several tables. With reference to the equations relating to the unit
pressures per square foot of projected area, the writer is pleased to be
* Electrical Engineer, New York, New Haven and Hartford Railroad.
252 DISCUSSION ON OVERHEAD ELECTRIC TRACTION [Papers.
Mr. Murray, able to confirm these figures in actual practice, as the catenary wires
and supporting structures in the New Haven electrification were worked
out by an equation practically identical with the one suggested by
Mr. Coombs; and it is of interest to note here that these wires and
structures have passed through storms approximating quite closely
those stated as maximum conditions upon which the equations are
based.
Mr. Coombs' specifications of general requirements are to the point,
and, in addition to those which are generally recognized as standard,
he has made many original and valuable suggestions.
In connection with the general subdivision of superstructures, al-
though the writer is not quite able to agree with Mr. Coombs that the
upright signals when supported from four-track trusses are obscured
from the engineer's view at a distance of 1 200 ft., it is unquestionably
true that the general envelope produces a difiicult foreground for the
engineer, and naturally the cross-span or cantilever-bracket construc-
tion clears up this disadvantage to a considerable degree.
As recently stated in a paper before the American Institute of
Electrical Engineers, the writer is not loathe to believe that even four-
track main-line electrification will be effected by the use of cross-
catenary spans interspersed at proper intervals with fabricated steel
truss anchor bridges; but believes that the form of this construction
will be guyed steel uprights siipporting the cross-catenary span, with
distances between bents of, say, not greater than 300 ft.; and, further,
he believes that, in the future, the single catenary will receive more
favorable consideration than the double catenary construction. It can
be readily seen that the first cost of the former will be much less, and
the flexible contact offered by the single catenary construction, due to
the fact that the trolley is supported from a single messenger, with the
messenger in turn supported from a flexible cross-catenary, gives it a
great advantage.
Practice seems to demonstrate the fact that either the shoe or the
trolley must be flexible. As a matter of fact, flexibility in both would
be of great advantage, and it cannot be questioned that the cross-
catenary span will offer more flexibility than either the cantilever or
bridge-truss type of construction. At this point, particular attention
is called to the fact that experimentation with the deflection of trolley
wire supported from a messenger, which is in turn supported at rigid
points, shows that in the middle of the span the deflection is as much
as 400% greater than that in the immediate vicinity of the bridge or
cantilever supporting the messenger wire, it being understood, of
course, that equal upward pressures are applied in each instance. This
illustrates the value of the flexible feature in the cross-catenary support.
A point of much value in the cross-catenary construction should be
emphasized, namely, that the cross-spans may be supported on strain
Papers.] DISCUSSION ON OVERHEAD ELECTRIC TRACTION 253
insulators, thereby not only doubling the actual insulating value of the Mr. Murray.
line, as measured under normal atmospheric conditions, but, in point
of fact, many times increasing the insulating value due to the insula-
tion being placed at the side, and thus out of the direct line of steam
locomotive blasts, which have such a deleterious effect on insulation.
An argument that will be advanced against the use of the cross-
catenary construction is that it is not as reliable as the cantilever or
truss construction. The answer to this is that, in this form of con-
struction, any factor of safety that may be used in other types can be
selected; in fact, larger factors of safety can be chosen with less pro-
portionate expense.
In conclusion, the writer agrees with Mr. Coombs in his summa-
tion, under five counts, concerning the undesirability of double cate-
naries. The root of all trouble with the alignment of catenary con-
struction is the change of temperature. The fact that a low tempera -
tiire means a tight wire and vice versa for a high temperature must
be considered. The ideal condition of suspension would be a free-
running suspended wire, tension being supplied at one or both ends
to counteract the variations in. its length due to temperature. It is
very seldom that ideal conditions can be secured in the field, however,
and the results are generally a combination of compromises and ap-
proximations. What one fails to accomplish with the contact wire
may be accomplished by a properly devised shoe, of strong construc-
tion, flexible and light, the last-named element eliminating inertia,
the arch enemy to the hard spots in the line, which, as Mr. Coombs has
pointed out, are at the "hanger points." To-day is not the time for
standardization, but for observation. The experiences and mistakes of
to-day will be invaluable in comparison with theories.
Vol. XXXIV. MARCH, 1908. No. 3.
AMEEICAN SOCIETY OF CIVIL ENaiNEERS.
INSTITUTED 1852.
PAPERS AND DISCUSSIONS.
This Society is not responsible, as a body, for the facts and opinions advanced
in any of its publications.
A NEAV SUSPENSION FOR THE CONTACT WIRES OF
ELECTRIC RAILWAYS USING SLIDING BOWS.
Discussion.*
By Messrs. R. D. Coombs and Charles Eufus Harte.
Mr. Coombs. R. D. CooMBS, M. Am. Soc. C. E. — The speaker is of the opinion
that interruptions in service caused by lateral displacement are im-
probable on either the 240-ft. spans with a sag of 2^ ft., as used by
Mr. Mayer, or on 300-ft. catenary spans having a sag of 6 ft.
Based on the fact that the hot and cold sags in the catenary, and
therefore in the trolley wires, are approximately equal for a total varia-
tion in temperature of 140°, the tension in the trolley wire is given
by Mr. Mayer as about 26 000 lb. per sq. in. Assuming that the cate-
naries are erected with the normal tension at normal temperature, it
would seem that the increased tension in the trolley wire should be
merely that due to a rise or fall in temperature of half the total varia-
tion.
The speaker is not familiar with the details of the automatic ad-
justment of the trolley wire used in the Blankenese-Ohlsdorf line, or
other foreign lines equipped with the secondary catenary, but thinks
it should not be necessary to run the comparatively inflexible trolley
wire over the adjusting pulleys, as this might be avoided by attaching
a flexible wire which would permit the use of pulleys of moderate diam-
eter.
The elastic limit, of from 40 000 to 45 000 lb., assumed for trolley
wire having an ultimate strength of from 60 000 to 60 000 lb. per sq.
in. seems to be rather high, and the maximum stress of about 26 000 lb.
* This discussion (of the paper by Joseph Mayer. M. Am. Soc. C. E., printed in
Proceedings for December, 1907), i.s printed in Proceedings in order that the views
expressed may be brought before all members for further discussion.
PLATE XXXIX.
PAPERS, AM. SOC. C. E.
MARCH, 1908.
HARTE ON
SUSPENSION FOR WIRES
OF ELECTRIC RAILWAYS.
Improvised - Atwood's Machine " for Testing the Stiffness of Trolley Wire.
Papers.] DISCUSSION" ON SUSPENSION FOR ELECTRIC RAILWAYS 255
per sq. in. in tlie trolley Avire under dead load, plus 6.0 lb. wind pres- Mr. Coombs,
sure, plus bending of the wire, does not give the contact wire in the
saddle suspension the same factor of safety as that used in designing
first-class railroad bridges.
A parallel condition to that of many railroad bridges would be dead
load, plus ice ^ in. thick, plus 8 lb. per sq. ft. for wind pressure, plus
lateral bending; the total stress from which would exceed 26 000 lb.
Assuming that the single catenary and the trolley wire supported
by it can be designed with suitable factors of safety, and constructed
so as to give satisfactory operation, the extra expense of the messenger
wire and hangers may be justified as a safeguard to prevent falling
v/ires and the troubles incident to them.
Charles Eufus Harte, M. Am. Soc. C. E. — Mr. Mayer has de- Mr. Harte.
veloped a very interesting construction which it is to be hoped may
have a practical trial in the near future. At the same time, it should
be noted that the excessive stresses feared by Mr. Mayer do not always
develop in the older forms of suspension. Undoubtedly, on long level
tangents, with heavy anchoring, there would be heavy stresses at low
temperatures, if the trolley had been well pulled up in warm weather,
but, as a matter of fact, grade changes and curves offer relief, and
trolley pulled to a tension of 2 200 lb. in summer apparently does not
materially increase this stress in winter imder usual conditions, owing
to the yielding of supports. Where trolley is hung slack, however, the
changes of length are chiefly taken up in the sag, and here an adjuster
may be desirable; but, certainly in New England, such a device must
be automatic or else receive constant attention in order to meet the
rapid and large changes of temperature of that climate.
A system of counterweights offers the ideal method of securing
uniform tension, and there is little difficulty in arranging bell-cranks
or of splicing into the trolley a section of steel strand, if the trolley
itself is too stiff to lead direct to the counterweights. It must be ap-
parent, however, to anyone familiar with trolley wire, that Mr. Mayer's
figures and practical conditions do not agree.
To determine roughly the flexibility of 0000 B. & S. gauge hard-
drawn, grooved copper trolley wire, the speaker arranged a crude form
of the "Atwood's machine," of physics, the trolley wire forming the cord,
and the head sheaves of a dumb-waiter the wheel. (Plate XXXIX.)
Balanced weights were hung from the wire, and then one side was
loaded until motion occurred. No correction was made for the con-
siderable friction of the wheels used.
With a pidley 65 in. in diameter at the root of the groove : 127 lb.
on each side required 13 lb. additional on one side to move; 232 lb.
on each side required 18 lb. additional on one side to move; and, 792
lb. on each side required 64 lb. additional on one side to move.
256 DISCUSSION ON SUSPENSION FOR ELECTRIC RAILWAYS [Papers.
Mr. Haite. With a wheel 33 in. in diameter : 232 lb. on each side required 33
lb. additional on one side to move.
With a wheel 17 in. in diameter: 127 lb. on each side required 83
lb. additional on one side to move; and, 324 lb. on each side reqiiired
155 lb. additional on one side to move.
The Blankenese-Ohlsdorf trolley is described* as a grooved wire,
having a gauge practically equivalent to 0000; Mr. Mayer gives the
area as 100 sq. mm., which is 3|% less than the area of the wire used
in the foregoing rough test.
For assistance in the tests, the speaker is greatly indebted to his
assistant, Mr. John F. Trumbull, and to Messrs. 0. W. Blakeslee and
Sons, Contractors, of New Haven.
* Street Railway Journal, April 6, 1907.
Vol. XXXIV. MARCH, 1908. No. 3.
AMERICAN SOCIETY OF CIVIL ENGINEEES.
INSTITUTED 1852.
PAPERS AND DISCUSSIONS.
Tliis Society is not responsible, as a body, for the facts and opinions advanced
in any of its jjublications.
SAFE STRESSES IN STEEL COLUMNS.
Discussion.*
By Messrs. Henry B. Seaman, Luzerne S. Cowles, Charles M.
Emmons, Henry S. Prichard, Horace E. Horton, F. P.
Shearwood, L. D. Rights, and A. W. Carpenter.
Henry B. Seaman, M. Am. Soc. C. E. (by letter). — It may be too Mr. Seaman,
early yet for a Special Committee to advise as to the proper column'
formula to be used in structural work, but Mr. Worcester's paper
brings us one step nearer its appointment.
To the writer's mind, there never has been sufficient reason for
abandoning the Rankine formula. The basis of its formation is the
provision that a column receives both direct strain and bending strain.
The direct strain is readily provided for, and the effect of bending is
found by experiment, the results of which are used in determining the
coefficient of r^. It would seem better to plot the results of these tests
upon the basis of ultimate strength, rather than working strength, as
it keeps the mind more directly on the actual data observed. The
formula can then be modified for working strength, either by taking a
certain proportion of the numerator as a factor, or by other modifica-
tion, if preferred.
It should be remembered that details are designed upon an assumed
value of , = 12, where I equals the length and d the least diameter of
a solid rectangular column. In designing columns, therefore, a greater
strain should not be permitted than that for which the details are de-
signed, that is, for a less value of , than 12. This serves, as Mr.
• This discussion (of the paper by J. R. Worcester, M. Am. Soc. C. E., printed in Pro-
ceecUnc/s for January, 1908), is printed in Proceedings in order that the views expressed
may be brought before all members for further discussion.
258 DISCUSSION OK SAFE STRESSES IN STEEL COLUMNS [Papers.
Mr. Seaman. Worcester has expressed it, to truncate the formula for very short
columns. Since the Rankine formula, however, provides for bending
as well as compression, it conforms with the tests on long columns bet-
ter than does the straight-line formula, and, for that reason, to the
v.'riter's mind, is the most valuable formula we have. There has never
seemed to be any excuse for the adoption of a straight-line formula,
except simplicity in plotting and ease in memorizing. Confessedly, it
does not conform to tests on long columns, it is not applicable beyond
certain restricted limits, and finally, since it involves r instead of r'^j
it cannot be used as readily without the assistance of tables; yet tables
will assist equally well with any formula.
A recent study of the tests mentioned by Mr. Worcester has led
the writer to adopt the following fonnulas :
For Steel and Wrought Iron: For Cast Iron:
8 000 7-2 1 000 r^
Mr. Worcester very properly calls attention to the fact that the
failure of a column occurs when it begins to cripple, while, with the
tension member, if allowed time to rest, the material becomes even
stronger because of the work of overstrain which it has received. This
would enable us to permit a higher factor of safety upon tension mem-
bers than upon compression members, were it not for the fact that a
permanent elongation of a tension member would deform the struc-
ture to such an extent as to change the strains for which it was de-
signed, and possibly cause failure on that account. It must also be
remembered that the element of fatigiae — and possibly that of moment-
ary impact — need not be considered in the bending of the column,
and therefore the extra material used, in order to prevent bending, is
an additional factor of safety, which the tension member does not
possess.
The recent tendency in structural design seems to be to increase
the live loading by a given factor in order to derive an equivalent
static strain, and then to design the parts for these static strains,
rather than the old method of using a factor of safety to cover defects
in material, increase, and extraordinary effects of loading, etc. If
the live-load strains can be increased so as to cover all possible con-
tingencies, and if a dead load can be assumed which will not be ex-
ceeded under any circumstances, it would seem safe to place the
allowable strain at one-half or two-thirds of the elastic limit. It is
on this basis that long-span bridges are designed ; and, by the adaption
of a formula in which this factor would vary with the various lengths
of span, the same method of proportioning could be adopted for shorter
spans. Future specifications will probably tend in tlu' direelion of some
such method of design.
Papers.] DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS 259
Luzerne S. Cowles, Assoc. M. Am. See. C. E. (by letter). — Mr. Mr. Cowies.
Worcester need hardly offer an apology for continuing the agitation con-
cerning compressive stresses to be allowed in designing structural steel-
work. The writer, from the beginning of his career, and in fact during his
college course, has been decidedly baffled by the numerous formulas for
allowable safe compressive stresses, and had begun to believe that most
so-called "rational" formulas were made up to assist the designer in
making a comparatively safe gxiess. The question arises, however, as
to whether all the commonly accepted formulas do really give the
margin of safety that is desired and is assumed to exist.
C. C. Schneider, Past-President, Am. Soc. C. E., has frequently
called attention to the fact that the elastic limit, and not the ultimate
strength, should be especially considered in deciding the real factor
of safety. This gives, for tension, and supposedly for compression,
a real factor of approximately 2, on the basis of 16 000 lb. per sq. in.
for static loads. The writer agrees with this, particularly where com-
pression is involved.
In the light of recently published data of experiments on full-sized
compression members, it would seem that this real factor of safety of
2 had even been seriously encroached upon, leaving far too lean a
margin of safety for structures where human life is at stake. When
one considers the astounding results of Mr. Buchanan's tests,* where
the fiber stress at crippling, even for so-called "short" columns, was
below the accepted elastic limit, it seems to be high time to consider
reducing the allowable unit stress for compression below that for ten-
sion, even though the modulus of elasticity and the elastic limit appear
in the laboratory, and no doubt are, approximately the same for each.
Most railroad bridge specifications insist that no compression mem-
ber shall have a length exceeding 100 times its least radius of gyration,
except for bracing, where a ratio of 120 may be used. In other words,
a main compression member in which the - is 100, will carry safely
f) 000 lb. per sq. in., whereas the use of a main member in which the
- is greater than 100 is disapproved. This is according to a standard
straight-line formula, and it seems that the use of very "long" columns
is not discouraged to the extent that it should be.
Is not then the really "rational" formula one which gives com-
paratively low results for the allowable fiber stress for the longest
columns consistent with good design, and errs on the side of safety
for the occasional exceptionally short strut ? Mr. Worcester's proposed
formula seems to fill these conditions, and while it may not be perfect
in its present .form, it is surely a step in the right direction, and fur-
nishes a basis for a truly sensible formula. With his customary
*Engineering News, Vol. LVIIT, pp. 685-695.
2 GO DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS [Papers.
Mr. cowies. modesty, the author of the proposed formula has failed to point out
its commendable features. The writer suggests the following:
(a). — Eeducing the allowable stress for "short" columns so as to
give a reasonable factor of safety;
(b). — Discouraging the use of columns in which the is greater
than, say, 90 to 100;
(c). — Placing the allowable stresses, for columns in which the
I
ratios of lie between 30 and 90, at figures which are
slightly below the average results, as shown by numerous
tests.
Charles M. Emmons, M. Am. Soc. C. E. (by letter). — The writer
is much interested in this paper. Mr. Worcester's plotting of the re-
sults of actual tests, reduced by a safe working factor, and also his
plotting of the several column formulas, to the same scale, reveals very
graphically the inconsistencies and the wide divergencies of these
formulas.
The writer is not as fully impressed with the idea of a formula
being self-limiting at the highest allowed value of • In attempting
to do that, the author's curve appears to be as inconsistent with the
tests as would be a straight-line formula. The writer realizes that a
formula should be of such form that, if the allowed value of be not
r
fixed arbitrarily, it will yet be in no wise dangerous, for the reason
that someone with more "nerve" than judgment, or through ignorance
or other cause, will occasionally use such a formula as
^ 3()000r-
to the limit. This danger was just lately brought to the writer's atten-
tion in a case where, for compression members, more than 10 ft. long,
having a stress of about 4 000 lb., a prominent engineer used a single
I
angle 2^- by 2 by i in. The is more than 300, and yet, according to
the formula, it should carry the load safely.
The use of any formula which may be based on a series of observa-
tions, like those given by the author, should not, with confidence, be
])ushed very far beyond the limits of those observations. Such a
formiila, however, should take full advantage of what is indicated as
safe by those observations.
Again, the formula proposed by the author, where one would be
practically limited to - = 112, would be prohibitive, in many classes
of work, especially for secondary members.
Papers.] DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS 261
In view of these considerations, the writer would prefer the use of Mr. Emmons.
a parabola with values, say, 12 000 (1 — "f^n 7x2 ) ' ^^^^^ ^^^' limiting
I
allowed value of prescribed. The formula is practically self -limit-
ing at = 150. It will be observed that this curve gives practically
the same values as the circle up to = 80, and from that point it
follows the tests far better, taking advantage of what the tests indicate
as safe, and yet in no case becoming dangerous.
Henry S. Prichard, M. Am. Soc. C. E. (by letter). — The intro- Mr. Pricimrd.
ductory paragraphs of this paper give the impression that the author
attaches slight importance to theory in regard to columns. Would it
not be well to discriminate somewhat in this regard ? It is unfortunate
that a single word, "Theory," is popularly used (with the sanction of
the dictionaries) to designate "a body of the fundamental principles
underlying any science or application of a science," and the radically
different conception "a proposed explanation designated to account for
any phenomena," no matter how visionary the assumptions, fallacious
the argument, or foolish the conclusion. It is natural and proper that
many of the proposed explanations of the behavior of columns should
be held in light esteem, but it is highly desirable that engineers should
understand and apply the principles of mechanics to the design of
columns. Without such an understanding, the phenomena observed
in practice and in the numerous compression tests are to a considerable
extent a set of seemingly discordant facts.
Referring to the fact that the practice of steel designers with re-
gard to columns may well bear further consideration, the author states:
"The reasor^ for this is that all 'rational' column formulas, based
on the elastic properties of steel, are founded on considerations which
are applicable only to ratios of length to radius of gyration far beyond
those allowed in actual construction."
It is difficult to reconcile this statement with the analyses and
equations developed by Euler, Cain, Fidler, Marston, J, B. Johnson,
Moncrieff, and others who have determined important facts regarding
short as well as long columns by reasoning based on the elastic prop-
erties of steel and iron. The names of Tredgold, Gordon, and Rankine
have purposely been omitted from this list for the reason that the
formula which they, by successive steps, developed is based on the
erroneous application to columns of the principle, strictly applicable
to beams, that the greatest possible deflections within the elastic limit,
of beams similar as to section, manner of loading, and end conditions,
are proportional to the squares of their lengths multiplied by the elas-
262 DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS [Papers.
Mr. Prichard. tic limit. In columns, nnder analogous conditions, the greatest de-
flections within the elastic limit are proportional to the squares of their
lengths, multiplied, not by the elastic limit, but by the differences be-
tween the elastic limit and the mean compressive stresses in the various
columns.
Euler's formula applies only to long columns, but he should be
included among those who, by analysis, have determined facts as
to short columns, for the reason that his formula carries with it the
necessary consequence that, under ideal conditions, columns which are
too short to have Euler's formula apply to them will have a uniform
distribution of stress and no deflection, up to the elastic limit, a con-
dition which is sometimes closely approached in laboratory tests. In
practice, of course, the conditions may be far from ideal, but Fidler,
Marston, J. B. Johnson, Moncrieff, and others have made valuable and
instructive analyses of the efi^ect, within the elastic limit, of departures
from ideal conditions.
The author objects to the practice of using the elastic limit as the
criterion of strength without regard to the ultimate. Wlien rest oc-
curs between the periods of straining beyond the yield point, the elas-
tic limit, which at first is somewhat below the yield point, can be
raised somewhat above it, thus making a permanent gain in strength,
the usefulness of which is greatly lessened by the fact that when
structural steel of the usual quality is overstrained it becomes very
4uctile.
When only a small portion of a steel member is overstrained, and
the conditions are such that a very small flow of the ductile metal
brings relief, the overstrained steel, by regaining its elasticity during
a rest, accommodates itself to the conditions with comparatively slight
distortion. Thus ductility, combined with the recuperative powers of
the steel, may be useful in adjusting the length and shape of members
and details, and in raising the strength of pins, etc., but if the stress
over the entire cross-section of a member is even slightly greater than
the yield point, and there is no other direct path for it to follow, the
member, if in compression, will buckle, unless it is very short and stifle,
and, if in tension, will elongate so much that it will not only be ir-
reparably injured, but will cause ruinous distortion in the remainder
of the structure, and possibly the failure of some adjacent compression
member, to the supposed weakness of which the disaster may be
erroneously attributed.
Between ruinous distortion and collapse there is a great difference:
Kuinous distortion means the loss of the structure, while collapse may,
in addition, cause great damage and loss of life. The possession of
strength in excess of the yield point, even though it be but temporary,
is, therefore, of some value, and a somewhat higher unit stress could
be allowed in members which possess it than in those which do not.
Papers.] DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS
263
It should be remembered, however, that even a tension member, from Mr
some action which starts from a nick, a flaw, a jagged edge, a thread,
or a rivet hole, or in some detail from no distinctive point, may break
without marked elongation, especially under shock.
There is no analytical method by which strength within the elastic
limit can be equated with strength beyond it, but, other things being
equal, would not an advantage of 4 000 lb. per sq. in. fully offset the
absence of any strength there may be in a highly ductile metal beyond
that limit? To assist in considering this question, the elongations
beyond the yield point during a test of a fairly typical eye-bar are
submitted in Table 1.
TABLE 1. — Elongation of a Typical Steel Eye-bar, Measured in a
Length of 262| In. from Center to Center of Pins.
Prichard.
Load per
Elongations:
Load per
Elongations:
square inch,
in pounds.
square inch,
in pounds.
Inches.
Percentage.
Inches.
Percentage.
35 000
0.55
0.03
45 000
6.92
2.64
36 000
2.07
0.79
50 000
9.75
3.72
37 000
2.75
1.05
55 000
13.60 5.17
38 000
3.77
1.44
60 000
30.63
7.84
39 000
4.21
1.60
64 410
38.25
14.6
40 000
4.56
1.74
56 710
40.65
15.5
A strain of 4 500 lb. per sq. in. in excess of the yield point, with
a percentage of elongation equal to the percentage in the bar cited, if
it occurred in the diagonal eye-bars of a bridge panel 25 ft. long by 25
ft. high, would cause a distortion of the bridge, in one panel length,
of 9-2- in. This would be a severe test of the floor system and top chords.
The relation of the yield points in compression to those in tension
was well shown by a set of comparative tests by the late Charles A.
Marshall,* M. Am. Soc. C. E., a synopsis of which is given in Table 2.
In Table 2 the strength of the steel increases, in a general way, as
the size and thickness of the sections are reduced. A similar variation
in the strength of wrought iron was shown, by tests made by the United
States Board on Testing Iron and Steel,t to be due to reduction in
rolling. In most cases, the results for compression are each an average
of two tests, and for tension, of three or four tests. The average of
the yield points given in Table 2 for compression is 1 432 lb. per sq.
in. greater than for the corresponding results for tension. The results
of these tests cannot be applied directly to tension in eye-bars. The
fact that eye-bars are annealed puts them in a different class from
material as it conies from the rolls, as the steel is softened, some of the
good effects of rolling are taken away, and the proportion of yield
* Transactions, Am. Soc. C. E., VoL XVII, p. i
t Vol. I, 1H81, pp. 35-45.
204
DISCUSSION OK SAFE STRESSES IN" STEEL COLUMNS [Papers.
Mr. Prichard. point to ultimate is lowered, especially if the bars are cooled slowly.
Except in rare cases, steel as it comes from the rolls will have a yield
point in tension exceeding 55% of its ultimate strength, while the
average of all the tests (some 570 or more) of full-sized eye-bars, made
during the last few years at the Ambridge plant of the American
Bridge Company, gives a yield point equal to 524% of the ultimate
strength of the full-sized bar, with variations above and below this
percentage. It is not wise to count on a yield point of more than 50%
of the ultimate strength of the bar.
TABLE 2. — Comparative Tests, in Tension and Compression.
All fi'om the same blow of Bessemer steel as it came from the rolls.
Yield Point.
Ultimate
strength in
teusion, in
pounds per
.square inch.
Size and sliape of
test piece.
Compression,
in pounds per
square ineti.
Tension :
In pounds per
square inch.
Percentage
of ultimate.
4 by ]/^ in
Not given.
49 055
Not given.
47 300
Not given.
43 845
46 020
Not given.
42 300
43 460
41290
53 800
47 815
47 363
46 090
44 417
44 273
44 202
43 560
41 527
41447
41415
41060
40 747
40 275
40 017
39 397
39 317
39 302
38 482
38 310
38 207
38 193
37 820
37 580
37 000
36 680
30 100
35 917
75.5
68.8
68.9
66.8
65.8
64.7
65.0
63.6
62.1
61.9
62.4
60.4
60.8
60.7
60.3
59.1
58.8
59.1
57.7
58;2
57.5
57.0
m.b
71255
69 390
3bv?^in
68 657
% in round
68 995
3 hv 1^ in
67 527
68 427
67 970
1 in .square
4 by 34 in
68 510
66 917
3 by % in
4 by 1 in ;
66 987
66 230
114 in square
67 973
67 040
114 in "
66 363
14d in "
42 075
Not given.
42 740
Not given.
39 940
66 333
3bv 1 in
66 700
66 833
3 by 2 in
66 537
3 bA' 1J4 in
66 640
Not given.
2 in. round
38 830
40 630
Not given.
36 840
Not given.
65 663
66 400
3 by 114 in
66 342
4 by 114 in
Not given.
65 460
Not given.
I. n
3 by 1^ in
65 762
It appears from the foregoing that the higher yield point in com-
pression, of steel as it comes from the rolls, as compared with the yield
point of annealed eye-bars, would about offset the advantage which the
latter possesses of some temporary strength in excess of the yield
point, even when the same ultimate tensile strength is specified for
the eye-bars, as determined by full-sized tests, and steel for compression
members, as determined by specimen tests. A comparison between
the strength of steel in compression and the tensile strength of built
Papers.] DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS 265
steel members is a different matter, and introduces a somewhat differ- Mr. Pilchard,
ent set of questions. Few engineers, however, unless they are opposed
to pin connections, would permit a higher unit stress for the net area
of a built tension member than for an eye-bar.
With the exception of columns made of pipes and single angles,
practically all columns are built of sections and plates. The rivets
are usually assumed to fill the holes and take the place, as far as com-
pression is concerned, of the sections they replace. As a matter of
fact, they do not completely fill the holes, and it is very doubtful
whether they wholly make good the loss in section. They are seldom
placed closer than an average of 4 in., and probably they are more
than half as effective as the metal they replace. On this basis, the
allowed stress per unit of gross section of column area would be about
seven-eighths of the allowed stress per unit of net section in tension;
that is, if 16 000 lb. per sq. in. is allowed in tension, 14 000 lb. would
be a corresponding limit for compression. There are other considera-
tions, however, chief of which is the weakening influence of slender-
ness in either the column as a whole, or in its details.
Notwithstanding the large number of tests that have been made in i
the endeavor to determine the influence of slenderness (Moncrieff, in
his paper on "The Practical Column,'"' cites more than 1000),* the
practice of engineers in this regard, as shown by the author, is very
diverse; from which it would appear that the lessons taught by the
tests are not very definite, or that they have not been generally under-
stood.
A knowledge of the principles involved is of great importance,
both as a guide to the making of useful tests and as a key to under-
standing the phenomena observed. The theory of columns has been
partially developed by correct analysis, but it has frequently been
elaborated so much that the essential facts have been buried under
what Trautwine called "heaps of mathematical rubbish." It may be
well, therefore, to present a concise analysis of the influence of length
and eccentricity on the strength and stiffness of columns.
Consider a column with frictionle.ss hinged ends, of length, I, and
radius of gyration, r, with constant cross-sectional area. A, subjected
to a longitudinal load, of intensity, p, acting with an intentional ec-
centricity, e, and an accidental eccentricity, e'.
In consequence of the eccentricity, there will be a primary inten-
tional bending moment, p A e, o. primary accidental bending moment,
p A e', and a secondary bending moment, p A ^ ; A being the de-
flection. The value of ^^ can be obtained from the well-known equa-
tion:
moment f
^ C E Ar"" ^^)
* Transactions, Am Soe. C. E., Vol. XLV, p. 334.
S66 DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS [Papers.
Mr. Prichard. in which E is the modulus of elasticity and G a factor which varies
with the shape of the moment diagram.
The moment diagram can be divided into two parts, the diagram
of primary moments and the diagram of secondary moments. For the
determination of the deflection due to the secondary moments, the
value of C will vary between limits of which the upper is n^ and the
lower depends on the form of the primary moment diagram: if it is
a rectangle, the lower limit will be 9.6, while, if it is in the shape of a
bow, the lower limit will approach very close to the upper limit,
n^ = about 9.87. The limits are so narrow that it can be taken as n'
without serious error.
For the determination of the deflection directly due to the primary
moment, the value of C will vary according to the conditions, but,
for convenience, it may be designated — . (If the cause of the primary
z
bending moment is the eccentric application of the load, z will equal
1.234, and C will equal 8; but, if the cause is a bow-shaped bend in
the axis of the column, z will be approximately equal to unity. In
the applications made subsequently in this discussion, z is taken as
equal to 1.234, which, in some cases, is a trifle high. The resulting
stresses and deflections, therefore, are a trifle high, especially for the
higher ratios of I to r.)
Substituting the primary intentional, primary accidental, and sec-
ondary moments in Equation 1 gives
zp A X' (e -\- e') p A A X-
A Tt- E v Atc-Ev
To simplify the development, let
^= -1^ ;••; ^"^
This is Euler's formula, and, as it facilitates the application of the
final equations to have the values of q, which may be termed a modulus
of rupture, determined for various values of and tabulated. Table ?>
r
is submitted.
Substituting q for its value in Equation 2, and reducing, gives
^^^t±(i±n (4)
q—p
Hence the secondary moment is
r) A A = p A (e -{- e') — - — z (f))
q—p
Let V = the distance from the neutral axis to the extreme fiber on
the concave side of the column.
The stress from bending, in the extreme fiber on the concave side
of the column, is 5 . Hence, if f = the combined stress
A r
in the extreme fiber on the concave side.
Papers.^ DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS 267
/ =. p + (JLlZ + P^^ ( 1 + _JL_ , ) (6) Mr. Prtc,.a„>.
In investigating physical laws, the work of the study and the
laboratory should be complementary — a proposition generally conceded,
but practiced too little in investigating the mechanics of structures.
TABLE 3. — Values for Modulus of Buckling.*
7r2 E
Values of the modulus of buckling, q
E = 29 000 000 lb. per sq. in.
I = length, in inches, r = radius of gyration, iu inches.
{'■)
I
r
Values of q.
■
I
r
Values of q.
I
r
!
Values of q.
■z
71555 000
82
42 567
162
10 906
4
17 889 000
84
40 564
164
10 642
6
7 950 500
86
38 700
166
10.387
8
4 472 200
88
36 9«0
168
10 141
10
2 862 200
- 90
35 336
170
9 904
12
1 987 600
92
33 816
172
9 675
14
1 460 300
94
32 393
174
9454
16
1 118 000
96
31 057
176
9 240
18
88:^390
98
29 802
178
9034
20
715 550
100
28 622
180
8 834
22
591 360
102
27 511
182
1 8 641
24
496 910
104
26 463
184
8 454
26
423 mo
106
25 473
186
8273
28
365 080
108
34 549 (
188
8098
30
318 020
110
23 655
190
7 929
32
279 510
112
22 8ir
192
7 764
34
247 590
114
22 024
194
7605
36
220 850
116
21 271
196
7 451
38
198 210
118
20 556
198
1 7 301
40
178 890
120
19 876
200
7 155
42
162 260
122
19 230
2(»2
7 015
44
147 840
124
18615
2lH
6 878 ■
46
135 260
126
18 029
206
6 745
48
124 230
128
17 469
208
6 616
50
114 490
130
16 936
210
6 490
52
105 850
132
16 427
212
6 368
54
98 155
134
15 WO
214
6 250
56
91 269
136
15 475
216
6 135
58
85 083
138
15 029
218
6 023
60
79 506
140
14 603
220
5 914
62
74 459
142
14 195
222
5 808
64
69 878
144
13 803
224
5 704
66
65 707
146
13 427
226
5604
68
61899
148
13 067
228
5 506
70
58 412
150
12 721
230
5 411
72
55 212
152
12 3&S
232
5 318
74
52 268
154
12 068
234
5 227
76
49 553
156
11 761
236
5139
78
47 045
158
11 465
238
5053
80
42 722
160
11 180
240
4969
* From Proceedings. Engineers' Society of Western Pennsylvania. July. 1907, p. 341.
268
DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS [Papers.
Mr. Prichard. To Substantiate Equation 4, which differs in form, but is actually
similar to one given by Moncrieff,* a comparison is submitted between
the deflections calculated therefrom and the actual deflections in tests
made at the Watertown Arsenalf of four wrought-iron columns; two
consisting of two 8-in. channels and one 12-in. cover-plate; and two of
two 10-in. channels and one 13-in. plate. In both cases the columns
were latticed on the side opposite to the plate, the length was 74 radii
of gyration, the load was applied by three ^-in. pins at right angles to
the webs of the channels, a-nd placed in the center of gravity of the
channels. The modulus of elasticity was assumed as 27 000 000 lb., and
the value of q correspondingly determined as 48 600 lb.
TABLE 4.
Test 1632:
Test 1633:
e- 1.62 IN.
e= 1.64 IN.
4 = 17.57 SQ. IN.
A^ 17.72 SQ. IN.
Load,
in
pounds.
Deflections, in inches.
Deflections, in inches.
Calculated.
Actual.
Calculated. Actual.
10 000
0.02
0.00
0.02 0.00
20 000
0.05
0.01
0.05 ' 0.01
50 000
0.12
0.10
0.12 0.09
100 oon
0.27
0.22
0.27 0.21
200 000
0.61
0.54
0.61 0..51
250 0(i()
0.83
0.77
0.8.3 0.74
280 000
0.97
0.95
0.97 0.91
SOOOOO
1.08
1.15
1.08 1.20
306 000
Ult. Load.
307 000
Ult. Load.
310 000
1.14
1.14
Test 350:
Test
351:
e = 1.7 IN.
e =
.3 IN.
A = 12.48 SQ. IN.
A= .
Load.
in
pounds.
Deflections, in inches.
Deflections
, in inches.
Calculated.
Actual.
Calculated.
Actual.
10 000
0.04
0.0
0.03
0.0
20 000
0.07
0.03
0.06
0.3
50 000
0.19
0.11
0.17
0.12
100 000
0.41
0.37
0.38
0.32
150 000
0.69
0.67
0.64
0.58
180 000
0.89
0.90
0.83
0.82
200 000
1.03
1.20
0.98
1.05
202 700
Ult. Load.
208 200
Ult. Load.
210 000
1.11
1.06
* Transactions, Am. Soc. C. E., Vol. XLV, p. 359.
+ Reports for 188:^, pp. 167 and 168: and 1884. pp. 54 and 55.
Papors.] DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS 269
Considering the fact that, in making the comparisons in Table 4, Mr. Prichard.
no allowance was made for unintentional eccentricity or pin friction,
the agreement is as close as could reasonably be expected. Monerieff,
in connection with his equation for deflection, previously referred to,
gives a large number of comparisons between deflections obtained by
applying his equation, and those observed in tests, which tend strongly
to establish its substantial accuracy.
The maximum compression in the extreme fiber of the column
bearing the test number 1632, has been calculated for the ultimate load
by Eqiuition 6, which gives 36 600 lb. per sq. in.
The amoimt of the unintentional eccentricity will fluctuate greatly
in practice, but, in devising rational formulas for use in designing,
either by direct application or through empirical formulas founded on
them, the greatest amount which is reasonably possible with ordinary
care should be assumed. The amount assumed should cover inac-
curacies in boring pin holes, the shift in the position of the axis from
over-runs, and shortages in sectional area as compared with the area
of the sizes specified, inequalities in the modulus of elasticity in dif-
ferent parts of the cross-section, curves or kinks in the axis, and
potential curves or kinks in the axis from the relief of internal stresses.
Owing to internal stresses produced by cold-straightening or otherwise,
the metal is likely to be overstrained in spots before that in the
main body of the column reaches the elastic limit. The internal
stresses may be relieved to some extent by overstraining followed by a
rest, but the column is likely to have a permanent deflection as a re-
sult thereof. From some causes, such as inaccuracies in pin holes,
short columns are likely to have as much accidental eccentricity as
long ones; while, from other causes, such as initial curvature of the
axis, the probable limit of eccentricity will vary with the length. The
e' V
following value for the factor, -^-, in Equation 0 is suggested:
r'
e^_ 1 _Z
T^ "~ 10 "*~ 700 7
For ordinary built coliimns with pin connections, in which the
relation of V to r is about as 7 is to 5, the eccentricity corresponding
to Equation 7 is :
e' = 0.07 r -f 0.01 I (,S)
For a column with a radius of gyration of 5 and a length of 500
in., the eccentricity given by Equation 8 is about | in.
From Equations 6 and ?, a formula can be deduced which will give
the load, p, per unit of column area, but such a formula is not sub-
mitted, for the reasons that it is so complicated and difficult of ap-
plication that it is of no practical value, and the results which it gives
for columns having a length of less than 100 radii of gyration can be
2 - T7T + ^7^ (')
270
DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS [Papers.
Mr. Prichard. jipproximated closely by short empirical methods. The method sug-
gested is as follows:
For structural-steel columns with hinged ends, the stress per square
inch, in pounds, in the most compressed fiber, from combined direct
compression and intentional primary bending moment, shall not exceed
f
35 000 — 1.5 2
1- (!»)
Factor required.
For a factor of 2.5, the expression becomes
r-
14 000 — 0.0
(1(1)
From Equations G and 7 it is evident that the minimum value which
can be assigned for the stress from the accidental bending moment is
O.lp^ from which it follows that a limitation of 35 000 lb. per sq. in.
for combined direct compression and intentional primary bending
moment corresponds to a limitation of 38 500 lb. per sq. in. for stresses
from all sources. Hence, if proportioning by Equation 9, with a factor
of one for maximum possible loads, gives results closely in accord with
theory, as claimed, the stress per square inch in columns thus pro-
l)ortioned, as determined by Equations 6 and 7, should be close to
38 500 lb. How close they come to this amount is shown by Table 5.
TABLE 5. — Maximum Stresses per Square Inch, Determined by
Theory (Equations 6 and 7) in Columns Proportioned by Rule
(Equation 9, with Factor of One), for Various Lengths and
Intentional Eccentricities.
The intentional primary bending stresses, in terms of the
LOAD, are given at THE HEAD OF EACH COLUMN.
I
r
0
O.lp.
0.5p.
P-
Pounds.
Pounds.
Pounds.
Pounds.
0
25
50
75
100
38 500
39100
39 100
39 400
38 700
38 200
39 000
39 200
39 800
38 800
37 300
38 100
38 600
38 500
33 900
36 750
37 300
.37 500
36 300
30 700
The agreement between theory and rule, indicated by Table 5, is
close, except for long columns and great eccentricities, for which the
rule requires a heavier column than theory.
Some opportunity for comparison between the theory and assump-
tions outlined on the one hand and experiments on the other is afi^orded
l)y the tests of mild steel columns with pivoted ends made by Professor
Papers.] DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS
271
Tetmajer."' Of the columns tested, the lengths of 27 did not exceed Mr. Pnchard.
100 radii, and they were loaded without intentional eccentricity. The
ultimate load in all cases was greater than indicated by Equation 9,
and less than required under ideal conditions for an elastic limit of
41 000 lb. and a modulus of elasticity of 29 000 000 lb. Table 6 is a
comparison of the ultimate loads given by Equation 9 and the lowest
of the ultimate loads shown by the tests.
TABLE 6.
I
r
Equation 9.
Pounds.
Tests.
Pounds.
I
r
Equation 9.
Pounds.
Tests.
Pounds.
80
40
50
33 650
33 600
31 250
39 000 about.
38 000 "
32 000 "
70
75
92
37 600
26 560
23 300
39 000 about.
28 000
33 000 '•
Eor columns of greater length than 100 radii of gyration, stiffness
rather than strength is the governing consideration. For this reason,
the loads allowed by Equation 9 are preferable to those allowed by the
theory of column strength.
To show the relative stiffness of columns 100 radii and longer in
length, when proportioned by Equation 9 with a factor of one, the de-
flections have been determined by Equations 4 and 8 for columns with-
out intentional eccentricity, with a radius of gyration of one, and
various lengths as shown in Table 7.
TABLE 7.
_
Length,
in
inches.
Deflection,
in
inches.
Ratio
of deflection
to length.
Length,
in
inches.
Deflection,
in
inches.
Ratio
of deflection
to length.
100
110
0.486
0.550
1:206
1:200
i
120
130
0.485
0.327
1:247
1:400
It will be noticed that the loads allowed by Equation 10 for columns
up to a length of 100 radii of gyration are about one-sixth greater than
those allowed by the author, but that there is a radical difference for
longer columns. The objection among engineers to columns longer
than 100 radii is largely sentimental. For the same load, a column
with a length of 120, 130, or 140 radii, proportioned by Equation 10,
in consequence of its greater sectional area, is stiffer and stronger than
one of a length of 100 radii.
* Transactions, Am. Soc. C. E., Vol. XLV, p. 404.
272 DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS [Papers.
Mr. Prichard. For derricks, poles, and other equipment used in building and erect-
ing, much longer struts are used than in bridge work, and, when the
loads are kept within rational limits, the flexibility of the struts, by
permitting them to absorb impact, is an element of safety. In the
ordinary affairs of life, long struts are used as a matter of course.
The engineer who becomes alarmed at long struts in structures will
bear his whole weight on a walking-stick, many times as flexible as
steel, with a ratio of Z to r of 200. Ample provision should be made in
horizontal and inclined struts for the stresses from their own weight.
The frequent neglect to make such provision in long struts has doubt-
less had something to do with the prejudice against them.
As regards columns, the greatest need for caution to-day is in pro-
portioning short stiff ones, which, to an engineering public accus-
tomed to gauge permissible unit stress by the ratio of length to radius
of gyration, have an appearance of strength not borne out by their
details, and, if their ends are square or fixed, they are subject to
strains from imperfect butt joints, or to secondary stresses produced
by the deformation of connecting floor-beams, etc. Such stresses are
greater for short than for long columns, on account of their greater
stiffness. In consequence of these facts, it is suggested that the
average load from direct compression per square inch of cross-sectional
area should not exceed 13 000 lb.
With the double requirement of Equation 10 and a 13 000-lb. limi-
tation for direct compression, if the permissible loads are plotted to a
scale for various ratios of I to r, the line indicating the maximum
permissible loads will suddenly change its direction at a length some-
what less than 41r, depending on the amount of the primary bending
moment. This is a feature which the author seems to consider objec-
tionable. It is entirely natural, however. Radically different condi-
tions govern the strength of very short and very long columns, and
the loci representing the loads under these radically different condi-
tions will intersect sharply. If there is no intentional primary bending
moment from eccentricity or transverse loading, 13 000 lb. per sq. in.,
unreduced, will govern for columns of shorter length than 41r, and
Equation 10 for columns of greater length, but if there is an inten-
tional bending moment, both requirements should be applied to de-
termine the governing one.
One of the assumptions from which Equation 10 was developed
was that of frictionless hinged ends. When there is no primary bend-
ing moment, any friction on the pins, according to strict theory, will
fix the ends; hence, it is not surprising that friction in pins is very
potent in increasing the resistance of columns to direct load in care-
fully devised and conducted tests. Such friction, however, is a very
poor reliance in practice, as it may be overcome by a little eccentricity
or shock.
Pai)ers.] DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS 273
Under ideal conditions, a column with strictly fixed ends has tlie Mr. Prichanl
same strength as a column of half its length with the same cross-
section and pivoted ends. In practice, however, the assumption of fixed
ends is never wholly realized. The appearance of having the ends
fixed is frequently deceptive, as compression members on opposite
sides of a joint may deflect in opposite directions in such a way that
the point of contrary flexure comes very near to the center of the joint,
which condition is equivalent to pivoted ends. For this reason, no
easement in the reduction for length, as given in Equation 10, is
recommended in designing new columns with seemingly fixed ends.
In determining the safe strength of a column in an existing structure,
however, if it is evident that the ends are well fixed, it might be as-
sumed that the column is as stiff as it would be if it were about three-
fourths as long and had frictionless hinged ends. For such an assump-
tion, Equation 9 would become :
Allowed compression per square inch in any fiber from comliined
direct compression and intentional primary bending moment for
columns with ends fixed equals
36 000 — 0.85 -,
Factor required.
In comparing this discussion with the writer's paper,* entitled "The
Proportioning of Steel Railway Bridge Members," it will be noticed
that the greatest compression now recommended is one-fifteenth less
than in the paper referred to, in addition to which a limitation for
direct compression to 13 000 lb. per sq. in. is now recommended. This
change is the result of a further consideration of the subject, in the
light of the Quebec Bridge disaster and the general discussion regard-
ing columns which followed it, including the paper by Mr. Worcester.
It should be stated, however, that it has always been the writer's prac-
tice in designing columns to give close attention to the details and to
the make-up of the section, and to make a liberal reduction in the
allowed unit stresses when the unsupported width of a plate exceeded
32 times its thickness. The following requirement as to the unsup-
ported width of plates is siiggested:
If the unsupported width, w, of any plate in a column is more
than 32 times its thickness, i, the permissible stress, as given by Equa-
tion 10, shall be reduced by multiplying it by the following expression:
2 ?o2
16 000 — -^
Permissible stress, as given by Equation 10, X
14 000
Horace E. Horton, M. Am. Soc. C. E. (by letter).— Mr. Worcester's Mr. Horton.
compilation of results of tests on full-sized wrought-metal compres-
*Proceedings, Enginews Society of Western Pennsylvania, July, 1907.
274 DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS [Papers.
Mr. Horton. sion members is very interesting and instructive, and is opportune.
There is an awakened interest in the subject at this time.
Wliile the writer approves unhesitatingly Mr. Worcester's criticism
on using excessive unit stress on members with short radii lengths,
he knows no physical reason for limiting compression members to a
length of 100 radii.
Mr. Worcester has chosen to make his platting of tests for steel on
the basis of four-fifteenths of the ultimate strength. For obvious rea-
sons, the writer uses the same. Mr. Worcester has used 12 000 lb. per
sq. in. as his unit value in compression, and the writer naturally uses
the same stress, with the reservation that the unit stress (tension) is
IJ X the compression, that is, 16 000, in this case.
The diagram, Fig. 2, gives all the tests of steel members shown by
Mr. Worcester, also tests of six members* by J. A. L. Waddell, M.
Am. Soc. C. E., and seven testsf by Mr. C. P- Buchanan, and, further,
six tests by the Chicago Bridge and Iron Works, on 8 by 8 by x^H"i"-
angles.
On this diagram a straight line is drawn through the center of
gravity of the group of tests, and is expressed by 11300 — 35 ^_ , also
the formula for loading, as indicated by C. L. Strobel, M. Am. Soc.
C. E., in his paper, "Experiments Upon Z -Iron Columns,":}: wherein
was first laid down the necessity of "sawing off" the unit stress for
short radii length, in this case to 8 000 lb. per sq. in., and also the first
appearance of the straight-line formula, which was 10 600 - — 30 .
The writer has platted Mr. Worcester's formula, based on 12 000,
and, as a protest against the attempted "amputation" for radii lengths
of more than 100, there is also platted the Hodgkinson-Gordon-Rankine
formula, as given by Mr. Worcester, based on 16 000, with a lower di-
visor of 8 000. It will be noticed that the platted lines come tangent
at 85 radii, and the two curves come somewhat above the center of
gravity of the tests. However, as these values are high for short radii
lengths, clearly indicating the necessity of "sawing off," the writer
offers the Hodgkinson-Gordon-Rankine formula, based on 12 000, with
a lower divisor of 12 000. When "sawed off" at two-thirds of the unit
stress (that is, 10 666 lb. per sq. in. as the ultimate value in com-
pression), and intersecting the curve at 40 radii length, it looks both
sane and safe.
The curve produced as platted, clearly indicates what is intended,
a value well below the average of the tests, and the value reduced so
that one may believe it to be reliable as the radii lengths are extended,
even to 200.
*The record of these tests appeared in Engineering Nen-s, January 16th, 1008.
^Engineering Newft, December 20th, 1907.
XTrnnsaclionx, Am. Soc. C. E., Vol. XVIII. p. 103.
Papers.] DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS
275
Mr. Hortoii.
27G
DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS [Papers.
Mr. Horton. The limitation to 100 radii length of compression members can only
be urged because of our want of knowledge, but practice and experi-
ence show that the greatest hazards are with short radii lengths, due
to want of proper proportion and cohesion of parts, and the tendency
toward using material which is too thin.
Unfortunately, engineering discussion as to the unit value of
compression members has been almost entirely on formulas, and not
on the physical column.
As to the physical compressive member, Mr. Buchanan gives a re-
port, with full details of tests to destruction, of nineteen full-sized
bridge members as built for actual use in structures — twelve of iron
and seven of steel. The first noticeable thing is that radii length has
no significance, in fact, members having a length of 83 radii were as
strong as any tested, and much stronger than many of less than 40
radii, and members of 97 and even 120 radii were a good average in
the whole group of tests.
The average ultimate strength of seven steel columns is 31 900 lb.
per sq. in. The average crippling strength is 23 800 lb. per sq. in. ;
the average elastic limit is 19 700 lb. per sq. in.
The ultimate strength, crippling strength, and elastic limit, in the
foregoing tests as reported, indicate a value of scarcely more than
50% of the value of the steel in tension. This is startling, with our
knowledge of specifications permitting the use of steel in short radii
lengths for approximately the same stress as in tension. Mr.
Buchanan's tests are given in Table 8.
TABLE 8.
Averaee of
Buchanan's tests.
I
r
Average of
T. H. and J. B. Johnson's
formula.
Crippling load.
Actual
crippling
load.
Below
estimate.
4 tests, 'Z,-ha,r columns
96
43.6
28 537
33 125
21 700
20 730
6 837
15 tests, trough and channel col-
umns
12 395
The four Z-bar columns lack, on an average from the computed
crippling load, essentially half as much as did the fifteen trough and
channel sections (the last with less than half the radii length), and
yet they actually stood a greater load.
From the photographs of the members taken after the tests, it is
seen that four Z-bar column struts yielded as a whole by flexure. The
fifteen other members yielded by some order of wrinkling or failure
in individual parts. It is further noticeable that the sections of the
Z -bar columns were much thicker, relatively. It is clearly apparent
that compressive members which fail by wrinkling fail at less load per
unit than those which fail by flexure.
Papers.] DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS 277
In the photographs of the material, after the tests by Mr. Waddell Mr. Horton.
referred to above (all of the same cross-section), it is noticeable that
members 81 radii long failed by flexure while those 27 radii long failed
by wrinkling. From the Buchanan tests there is abundant evidence
to conclude that the best results are obtained when the member yields
by flexure. From Mr. Waddell's tests there is evidence that, for the
best results at 27 radii, the material must needs be thicker than for
81 radii. Here is a suggestion, to be enlarged on later.
Wliile the radius of gyration has use, as indicating the value of a
strut, there is much to show that there are many other conditions of as
great importance as the radii length.
The radius of gyration will modify and hold in check any disposi-
tion to use material of undue thickness, but the radius of gyration has
to be held in check unless too thin material be used. The radius of
gyration of a transverse element of the column may be used as such a
check.
The composite nature of the compression member directly reduces
its unit value, as compared with tension, a very material amount. This
is directly traceable to the possible rivet efficiency connecting parts,
and it is undoubtedly a fact that rivets are driven much too far apart.
Two or three times as many rivets would surely give better results.
Rivet connections between multiple plates, or plates and angles, form-
ing a compression member, to reduce the tendency to wrinkling, are
clearly different from tension connections, and the efficiency has to
be considered locally.
With material half as thick as the rivet diameter, an efficiency of
50% may be obtained by pitching the rivets at 2.3 diameters; but,
with material the thickness of the rivet diameter, and rivets pitched
at 2 diameters, an efficiency of connection of 30% is all that is possi-
ble. In practice, rivets are generally driven with three times as much
pitch as here indicated, and the assertion may be made that the effi-
ciency of the connection of parts by rivets scarcely exceeds 12 per cent.
The cross-section of the compression member is unquestionably of
great significance. The proportions of the material in the flanges and
its width and thickness undoubtedly have paramount importance.
The compression member, with ever-increasing tendency in the evo-
lution of design, has developed with one or more open sides on which
lattice bars are used.
The proportions of such lattice bars, their connections to the
columns, and their relation to a force acting through the compression
member form a very material and important element, second to none
in the design. At the present time, there are in the technical press
many letters from correspondents, with elaborate formulas in which
E represents the modulus of elasticity, and e the eccentricity. As e,
eccentricity, is arbitrarily assumed, the writer prefers to assume a per-
centage of the compression through the column, and call it shear.
278 DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS [Papers.
Mr. Horton. The difference between the eccentricity discussed and the shear
outlined is as follows: Eccentricity is an assumption without refer-
ence to the magnitude or amount of the force acting on the member,
while the shear is a direct percentage of the force acting on the mem-
ber. One leads to the discussion of how accurate the workmanship of
the column may be, or is. The other asserts the fact that there must
be some relation between the force acting through a compression mem-
ber and its disposition to "side-step." This uncertainty is not caused
by faulty workmanship, but comes from a want of research and knowl-
edge.
In all the years past the whole discussion and the specifications for
compression members have absolutely ignored both shear and eccen-
tricity as items to consider, except in what has appeared within a very
short period, and there is no evidence that our workmanship has espe-
cially deteriorated in the immediate past, but there is reason to hope
that our knowledge of design may be enlarged.
Figs. 3 to 15 are given in order to indicate to the eye the relation
of various sections expressed by the radius of gyration; each section
has the same cross-section, namely, 12 sq. in.
Fig. 3 is a solid, 3.46 in. on a side, radius of gyration = 1.
Fig. 4 is a hollow square, 5 in. on a side, metal f in. thick,
radius of gyration =^ 2.
Fig. 5 is a hollow square, 7| in. on a side, metal if in. thick,
radius of gyration = 3.
Fig. 6 is a hollow square, 10^- in. on a side, metal ^f in. thick,
radius of gyration = 4.
Fig. 7 is a hollow square, 12| in. on a side, metal ^f in. thick,
radius of gyration = 5.
There are changes in the radius of gyration of from 1 to 5, with
the same cross-section, with a diminishing thickness of the material,
and an increasing unit value of the material by all compression
formulas.
Figs. 8 to 15, inclusive, are interesting as indicating 12 sq. in. of
section, in quite familiar shapes, with a radius of gyration of 6.
Appended to compression formulas it is quite usual to find a limi-
tation of thickness to width, of 1 to 30, and Figs. 8 to 15 can only be
objected to on this limitation, and not as to the radius of gyration.
According to Mr. Worcester's curve, as platted for working loads
on columns 10 ft. long, Figs. Y to 15, inclusive, may be worked for
11 800 lb. per sq. in. ; Fig. 6 for 11 700 lb. ; Fig. 5 for 11 300 lb. ; Fig. 4
for 10 400 lb. per sq. in.; and Fig. 3 for zero. With this conclusion
the writer does not agree. Figs. 4 or 5, undoubtedly, will carry the
largest load of any of the sections, 3 to 15, inclusive, at 10 ft. long,
while Fig. 3 will undoubtedly be a close second.
Papers.] DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS
279
Mr. Horton.
-15)4-
rr (Tj
;/--
S..B a
fc
\
V25K-
3:
H p I'
ri/-
-2.53^-
H
■11—
J
cc
'■
p
^
^
s
a
i<
tg
-i
c
<r.^'
^-H
L-4^ 1
Ul
•^
t
a
*
^
03
■^+°
,,
I
9 E
•2 ^i:
3
M®
4^
11
rf IK
B
280 DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS [Papers.
Mr. Horton. The Writer would extend the radius of gyration to the elements
making up the cross-section of a column, thereby limiting the thick-
ness of the material. The radii length on a transverse section of a
plate should never be more than the radii length of the column of
v;hich the plate is a part, or if it is, such parts should be used at a
decreased unit stress, found by substituting the value of thus obtained
in the general formula.
Angles should be one-fifth the size of the transverse dimensions of
a member, and not less than the thickness of the plates.
In the case of columns with projecting portions, such as angles,
Z's, etc., (where I = projection and r = radius corresponding to
r
thickness) must be doubled and substituted in formulas.
Where a part is made of several thicknesses riveted together, the
transverse radius of such a part will be taken as the radius of the
same as though solid and divided by the square root of the number
of pieces used.
The radii length of a lattice panel or the pitch of the lattice, with
the radius of gyration of neutral axis parallel with central line of the
web, of a built channel or similar section, should never exceed the
radii length of the entire member. The lattice need not exceed two
diameters of the rivet. The radii length of the lattice between the
connections should not exceed the radii length of the member on which
the lattice is used.
The lattice should have the ability to carry shear, assuming the
column to be supported at its two ends or in the center :
1. — At the unit strains allowed in the column itself, an assumed
uniform load equal to 10% of the load sustained by the
column ;
2. — At a unit stress of half the above, the weight of the column
itself.
The writer wishes at this time to emphasize his faith and belief in
proportion — the "Rule of Three" of our ancestors. It is the funda-
mental basis of comparison in all things.
Table 9 is an outline for five 2-built channel lattice columns.
Each column is in exact proportion, by the ratio of 2, in all its
three (and more) dimensions, to the next of the series. It follows at
once that the cross-section of the columns will be as the square, and,
for the same radii length, their weight as the cube. The writer has
outlined for the center of this group of five columns a rationally pro-
portioned 12-in. 2-built channel column having a section of 23 sq. in.;
he has also doubled it, and doubled it again. He has also divided the
12-in. 2-built channel column in each of its dimensions by 2 and by 4,
and in this tabulation by direct proportion there are five 2-built chan-
Papers.] DISCUSSION ON SAFE STllESSES IN STEEL COLUMNS
281
nol columns. There is every reason to believe that the 3-in. 2-built Mr Horton
1
channel column, at
4 096
part of the weight for a proportional radii
length of the 48-in. 2-built channel column, can be investigated with
reasonable certainty as to any in the group of columns that are in di-
rect proportion in all their elements, that is, size of rivets, size of
lattice, and pitch of rivets; and it is in this way that research can be
carried out at comparatively trifling cost. With the testing machines
already available, the truth can be developed as to any or all of the
moot questions as to value of cross-sections and radii length.
TABLE 9.
Built
channel
columns.
Section.
Area, in square
inches.
m
3
ai
>
(5
*
1
0)
3
f R. of gyration,
^" neutral axis,
I parallel to center
^ line ot web.
"Is ^
Plates.
Angles.
3-in.
6-in.
12-in.
24-in.
48-in.
2 - 3 X i
2 - 6 X J
2 - 12 X i
2 - 24 X 1
2 - 48 X 2
4— IX f X g
4— 11 X 1^ X J
4-3 X 3 X ^
4-6 X 6 XI
4-12 X 12 X 2
1.44
5.75
23
92
368
1.08
2.17
4.33
8.66
17.32
sin.
I-in.
li-in.
3 -in.
f Xi
Hx^
3 X 1
6 X2
0.22
0.43
0.86
1.73
3.55
9 ft.
18 ft.
36 ft.
72 ft.
144 ft.
Table 10 is a second compilation for five columns having the same
areas and dimensions as the columns in Table 9.
TABLE 10.
Section.
3 .
CTCO
te a)
<
i
CO
3
•3
CO
Rivets.
Double lattice.
R. of gyration,
neutral axis,
parallel to center
line of web.
Built
channel
columns.
Plates.
Angles.
c
48in.
24-in.
12 in.
6-in.
3-in.
8 - 48 X 1
8-24 X in
8—12 X;/j
8- exs'i
8- 3XtIb
4 - 4J X 4i X 1
4 — 2i X 2i X ^
4-11 XUXi
4 - t'b X i»B X J
4 - s'l X 5*5 X i'b
368
92
23
5.75
1.44
14.82
7.41
3.71
1.85
0.93
1-in. 4 X i
A-in. 2x8
i-in. 1 X ?e
i in i X ii
iVin- i X b\
1.38
0.69
0.35
0.17
0.09
124 tt.
62 ft.
31 ft.
16 ft.
8 ft.
The columns in this group will not require a testing machine, be-
cause when we have divided down from 48-in. 2-built channel columns
to the 12-in. 2-built channel columns, 23 sq. in. in area, and find four
12-in. plates massed together making 12 by | in. of metal combined
282 DISCUSSIOX ON SAFE STRESSES IN STEEL COLUMNS [Papers.
Mr. Horton. with 1^ by 1^ by, ^-in. angles with 1 by x\-in. lattice, all secured by
|-in. rivets, common sense will indicate that the columns in this group
should not be used.
The "Riile of Three" may be accepted as an agent, to assist in ap-
proaching the testing machine with columns of a size and cost so that
we may hope for extended research. The "Rule of Three" may also
be accepted as an agent to assist our common sense, as shown in the
second compilation.
In the foregoing, the writer has attempted to point out the de-
sirability of using all the rivet section possible in combining the parts
of a composite compression member.
All research which is available indicates that the thickness of the
material in the rectangular compression member has most to do with
its efficiency, thick material being required for short radii length, and
reducing in thickness as the radii length increases.
The piling together of relatively thin plates in multiple, with a few
tack rivets, and assuming that the mass is homogeneous is dangerous.
Some comprehensive proportion of stress through the compression
member must be accepted as shear, and must be provided for; if, on a
12 or 15-in. 2-channel strut of medium size, practice dictates lattice
of a weight equal to, say, 30% of the scantling weight of the member,
the "Rule of Three" will indicate that these same relations must be ex-
tended to large or small members.
It is not formulas that are needed to extend our knowledge of the
compressive member, but comprehensive research by physical tests.
Mr. Shear- F. P. SiiEARWOOD, M. Am. Soc. C. E. (by letter).— Mr. Worcester's
wood, curve appears to be more rational than any of the others he has plotted;
still, in common with all column formulas, his assumes that the
flexural stresses only result from the tendency of the member as a
whole to bend, and no reduction is allowed for the secondary bending
from the unsupported component parts and other unavoidable bending
stresses which occur in many of the compression sections now in use,
and especially in those having radii of gyration relatively large in
• comparison with their areas.
Strict adherence to a specified column formula has perhaps done
very much to force designers to use compression members which are
undesirable in nearly every way except that they meet the requirements
of the formula economically as regards material.
All, or nearly all, specifications have called for the unit stresses
in columns to be determined solely by the ratio of their length to their
radius, the latter to be calculated from the moment of inertia of the
section, without regard to whether the lattice (if used) is capable of
developing it, or whether, in so doing, secondary stresses are induced.
The latticed double channel section with flanges turned out, so fre-
qiiently used for compression members of truss bridges, is a good
Papers.] DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS 283
illustration of tlie incompleteness of the ordinary column formula, jyjj. g^ear
This section is generally used because, with a given width from out wood,
to out of chord gusset plates, it will give a strut having the largest
radius, and therefore the highest permissible unit stress; but, if in-
vestigated, it will be found that the following stresses are almost in-
evitable in such a section, and of these the column formula takes no
account, and they are practically unprovided for :
I. — Stress due to the flexure of the unsupported parts between
lattice-bar connections, which is coincident with that due to the flexure
of the column as a whole;
II. — Stress due to the eccentricity of the end connections, since
the center of gravity of either channel is usually some considerable
distance from the center of the gusset plates;
III. — Stress due to the eccentricity of the lattice-bar connections;
for it is usually impracticable to arrange the bars so that they will
intersect on the center of gravity of the channel ;
IV.- — Serious but less determinate stresses are probably induced at
or near panel points, where, owing to the necessary connections, it may
be impracticable to provide the last few feet of an important com-
pression member with either tie-plates or lattice bars; and, even when
center diaphragms are provided, the continuity of the lattice system
is broken up, resulting in unknown bending moments in the member.
V. — In nearly all bridges, the loads are applied more or less on the
inside of the trusses, thereby inducing longitudinal shear in the sev-
eral members, which in turn must stress the eccentrically connected
lattice bars, and increase the local stresses, as in III.
VI.— Lattice bars, having of necessity to be placed at an aiigle to
the direct stress of the member, create a distortion and bending when
the main member is under strain.
Most of the foregoing defects are absent or are minimized in mem<
bers having plate diaphragms, such as H -shapes, which are symmetrical
about every axis. Secondary bending is largely eliminated, and all
metal resists stress in direct lines to the applied loads. They are well
adapted to transfer any uneven application of load, but, unfortunately,
owing to their relatively small radius, they cannot be made to figure as
economically as flimsy latticed members.
It seems to the writer that columns with their several parts tied
together with solid plates should have more favorable consideration
than those which are occasionally tied together with redundant and
stress-inducing lattice bars.
Mr. Worcester, in common with many other authorities, apparently
attributes no advantage to fi:xed ends over pin ends.
It would seem reasonable that members with fixed ends should have
their lengths multiplied by some factor (say 0.7) when the allowed
unit stress and limiting lengths are computed.
284
DISCUSSION ON SAFE STT?ESSES IN STEEL COLUMNS [Papers.
Mr. Shear-
wood.
Fig. IG is given as an example, and shows the direct unit stress
allowed by the straight-line formula of the American Railway Engi-
neering and Maintenance of Way Association, in which only the
flexure of the column as a whole is considered, and also that permissible
if the flexure of the unsupported portions of the individual leaf and
bending from the eccentricity of the lattice bars are also provided for.
Radius of {f yi'atiou = 5.9"
" •' '" of single leaf = O.ili"
Area of section ^ 33 sq. in.
Allowea stress by straight-line formula = ICOOO-7O7 =1 lT:iO lli. per S'l. in.
Permissible stress if some of the other stresses due to flexure are provided for.
Unit stress ICOOO
Deduct for flexure of Column as a whole 4280
"' " " " unsupported leaf 1370
" " bending stress from eccentric
lattice connection [TOO CS-TO
9050 Permissible Stress
Fig. 16.
It seems probable that the disregarded secondary flexural stresses
in latticed columns have caused the tests on short lengths to disagree
with column formulas which are based on the compression value of
the metal. In devising a new column formula, the many inherent
weaknesses of latticed forms should be taken into account. Such a
formula would have the advantage of discouraging the use of ex-
aggerated forms with redundant metal, and encouraging the use of
members with continuously connected component partg.
Mr. Rights. L. J). RiGHTS, Assoc, M. Am. Soc. C. E. — This paper brings for-
ward a subject which is of interest, not only to engineers who work
with structural steel, but to all constructors who use columns of other
material.
Believing that there is a feeling among a number of engineers
that the "factor of ignorance" in regard to steel columns has an in-
sufficient margin, the author considers all the available tests, reduces
them to equivalent working values, and plots the results. He then
breaks away fropi any attempt to assume a theoretical formula, and
introduces a c^^rve which agrees fairly well in its middle portion with
Papers.] DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS 285
the average of the tests, and has the limiting values of 12 000 lb. at Mr. Rights,
cue end and 120 at the other.
As shown by tlie author's diagram, Fig. 1, most of the formulas
now in common use indicate considerably higher values than those
given by the proposed curve, and the question at once arises whether
engineers are warranted in making such a radical reduction. In the
light of present knowledge, the speaker does not feel that it is advisable
to take such a step. Many of the tests which the author has plotted
are from twenty to twenty-five years old; some of them are on plain
shapes, and many of them, as indicated, are for iron. The present
practice has been built up from these same tests, and is an attempt,
perhaps in a makeshift way, to accommodate itself to the improved
conditions of manufacture and details, which have changed materially
since the tests were made. It is the speaker's belief that engineers
would hardly feel justified in recommending this increased expense to
their employers or clients.
Although the speaker cannot agree with the author as to the large
reduction proposed, nevertheless, he feels that some enthusiasts, over-
confident in the supposed knowledge concerning the present state of
manufacturing, have increased the working values beyond safe limits,
and he would suggest that there is a middle ground. He would like
to offer as a temporary formula, and more or less of a compromise, the
straight line produced by 15 000 — 75 .
For the initial point, 15 000 lb. seems to be a .satisfactory value.
A very large proportion of the steel now used has an average ultimate
stress of 60 000 lb., with an elastic limit of 33 000 lb., and the values
suggested, if properly reduced, would come within what is, at present,
considered a safe limit. It will be noted from the diagram. Fig. 17,
that this straight line agrees with the author's plotted tests in the
middle portion fully as well as the proposed curve, and that it would
be practically tangent to the proposed curve at this position.
While it is desirable to cut off the column formula at some higher
value of , the question also arises as to where this point shall be. Some
r
engineers favor 100, others, 120, others, 125, and all of them probably
have had occasion at some time to consider columns at even a higher
value of - than 125. When such high values become absolutely neces-
r
sary, the engineer uses the old formula with discretion. It is the
speaker's belief that, instead of attempting to saw off the curve at
some arbitrary point, it should be made fool-proof by giving it safe
values above 200 . . It will be seen that the proposed straight line
28G
DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS [Papers.
Mr Rights, would end at 200 , and would give fairly low values between this and
r
120
I
In the light of our present knowledge, or ignorance, the straight-
line formula would seem to be adequately accurate for all practical
use, and the speaker feels that engineers could not do better than
adopt such a simple formula until more is learned about the subject.
\
\
s
\
-iv.
^
/-
^-1
\
\
N
N
J/T'''
\
\
s
s.
\
-
^
V
X
\
10000
-^
s.
%
^%
\
s
\
^
^'
\-
\
8000
N
1
[V
\
\
^
\
^
It-
%,
\
\
6000
\
\
N
X
^
^^
\
X
^
\
W\
\
N
s
\
■^
\
N
N
s
2000
!t\\
'■X
l>
S
N
-
^^
\
\
0
\
\
J
0 i
0 ;
0 1
u
jO i.
u
U i,
0 <
0 10
0 11
0 1^
0 lo
U 11
0 10
0 11
0 1-
0
18
0 It
0 200
DIAGRAM OF COLUMN FORMULAS
Fig. 17.
The speaker's suggestion would be that engineers either stick to
their present formulas, using them in a conservative manner, or adopt
some simple straight line, as suggested herein. New tests are needed,
not new formulas, and, until these tests become available, it would be
better for engineers to work conservatively along the lines they have
been taught.
Mr. Carpenter. ^ W_ CARPENTER, AsSOC. M. Am. SoC. C. E. (by letter).— Mr.
Worcester apparently overlooked the fact that full-sized tension mem-
bers do not develop the strength of specimen test pieces, and his com-
parison of the ultimate strength of full-sized columns with the ulti-
mate tensile strength of test specimens, therefore, is hardly on a fair
Papers.] DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS
287
basis. In proof of the statement that full-sized tension members do Mr. Carpenter.
not develop the strength shown by test specimens of the same material,
the writer would cite the tests* by J. E. Greiner, M. Am. Soc. C. E.,
on built-up tension members; the "Tension Tests of Steel Angles with
Various Types of End-Connection,"t by Frank P. McKibben, M. Am.
Soc. C. E. ; and any bridge engineer's records of tests of full-sized
eye-bars.
Table 11 is a summation of the results of these tests in form to
bring out the point desired.
TABLE 11.
Description of tests.
Specimen tests.
J. E. Greiner's tests of built-up ]
tension members: Nos. 3 to 10 of
Series A; Nos. 11 to 18 of Series
B: Average of 16 tests of full-
sized members
J. E. Greiner's tests of single-an-
gle tension members connected
by both legs: Average of 4 tests.
McKibben's tension tests of single
angles connected by both legs: - „f„„i
Average of 12 tests ; \ sieei.
Average of 70 tests of full-sized
eye-bars reported in Mr. Grei-
ner's paper
Average of ^ tests of eye-bars 10
by Its to ly% in., made under the
writer's direction
g
OJ 0,0"
Mild
steel.
Mild
steel.
Mild
Medium
steel. (?)
38 aso
■37580
3S040
37 342
58200
57280
56 480-
63 582
- 40 187 1 61 630
Full-sized
TESTS.
"Si
a &e
- o 3
3 '^si
s.a'^'.S
= iSj-^ P
j s a 3
-= oj s S
45 030
27 450
Not
given.
31270
30 440
50 650
51050
- 46 750
57 745
59160
Ratio of
full-sized
to specimen
TESTS.
0.73
0.84
0.76
0.87
0.89
0.83
0.91
0.96
Note. — All test specimens unannealed, except those of the last item.
It should be stated that, of Mr. Greiner's tests on built-up mem-
bers, Nos. 1 and 2 of Series A and all of Series C were excluded from
■J'able 11 for the reason that the members all had defective (inten-
tionally so designed) end connections; likewise, only the angles which
were connected by both legs in the angle tests mentioned were con-
sidered; therefore, the results are the most favorable possible toward
the best development of strength.
The high ratios of ultimate strength of eye-bars to that in speci-
men tests must be considered badly offset by the low yield-point ratios.
The yield-point ratios for Mr. Greiner's angles are certainly not favor-
* Transactions, Am. Soc. C. E., Vol. XXXVIII, p. 41.
t Engineering News, July 5th, 1906.
288 DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS [Papers.
Mr. Carpenter able to the tension side of the ar^iment. The other tests by Mr.
Greiner were made on members built of small sections, which probably
accounts for the high yield-point values. Following the usual laws,
lower results for yield point and (in lesser degree) for ultimate strength
would be found in the members of truss bridges and other structures,
which are built of thicker sections.
It would seem that, excluding eye-bars, it would be unsafe to call
the average ultimate unit tensile strength of full-sized tension mem-
bers more than 0.85 times the corresponding strength of test specimens
of the same material ; or, assuming 60 000 lb. as the ultimate unit
tensile strength of structural-steel test specimens, the corresponding
average strength of full-sized tension members would be 51 000 lb.
Now, put Mr. Worcester's Diagram of Column Formulas on the basis of
16 000 . ^ , . 16 000 16 000 „ , _ _,
517)00 ^"^ ''''^ ^"'^ rX^TTO "^ 42^ ^°^- ''''''^^'' """'^^ ^"'^ '^''
value he has chosen as the unit stress for the ratio, _ = 0 (12 000 lb.),
will become 14 000 lb. (practically).
Mr. Worcester entirely disregards the effect of end conditions on
the columns tested, treating columns with flat and hinged ends alike.
This seems to be rather unsatisfactory, since the theoretical influence
of the end conditions on the strength of columns is well backed up by
tests, and, undoubtedly, conditions arise which justify a distinction in
this regard.. The writer is wholly in favor of a single formula *f or
bridge work, and that based on hinged ends, since this condition is
closely approximated in pin-connected members, and the strengthening
effect of greater fixity of ends in members with riveted connections is
offset in unknown degree by secondary stresses and unavoidable eccen-
tricity of loading. It would seem preferable to base a curve on, or
compare formulas with, full-sized tests of columns the end conditions
of which are alike. For building work and special cases, in which the
condition can be unquestionably realized, a formula for columns with
fixed ends would seem to be entirely proper.
Mr. Worcester mentions the tests of Tetmajer, Marshall, and
Christie as ''full-sized." In his excellent paper, entitled "The Prac-
tical Column under Central or Eccentric Loads,"* Mr. J. M. Moncrieff
gives separate diagrams covering all the important series of tests of
columns made, up to the date of the paper, and apparently includes
all the tests cited by the author. According to these diagrams, the
tests of Tetmajer, Marshall, and Christie were on very small "full-
sized" members, generally, such as bars 1 in. square, small angles, and
other shapes and tubes. It seems that some distinction should be made
between these (especially the solid bars of insignificant size) and large
*Transact{ons, Am. Soc. C. E., Vol. XLV, p. 334.
Papers.] DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS 289
columns, such as those tested by Bouscaren, Strobel, and the Water- Mr. Carpenter,
town Arsenal. It was noted that the particularly low result of 28 000
lb. ultimate strength for a column having = 30 was obtained in
the series of "55 tests at Watertown Arsenal of 3-in. square bars (cold-
straightened), mostly on pins IJ in. in diameter, eight being on pin.s
from I in. to 2-i in. in diameter," all of wrought iron. It would seem
that such tests should be given very little weight in this consideration.
The writer has failed to note any test of a properly-constructed, cen-
trally-loaded large column which gives any such low result. The
author's statement regarding a factor of only 2 between the ultimate
strength of columns and a working stress of 16 000 lb. per sq. in. in
compression seems to be misleading, because, if the 16 000 lb. be con-
sidered the constant for reduction in one of the usual column formulas,
such tests as have been made on large columns show an average factor
of considerably more than 2 — perhaps 2.5 for mild steel — and it has
been pointed out that the average factor in tension is about 3.2. The
range of variation from the average is thought to be about the same
in tension as in compression. A careful study of tests of large steel
columns leads the writer to think that it would not be far wrong to
take, as the value representing the ultimate strength of well-propor-
tioned and properly-detailed columns, in the numerator of the Gordon-
Rankine or other equivalent column formula, 41 000 lb. for mild steel
and 36 000 lb. for wrought iron. These values would require, for equal
factors of safety based on ultimate strength, approximately the follow-
ing comparative values :
For tension in steel, 16 000 lb. per sq. in.
For compression in steel, 13 000 lb. per sq. in.
For tension in wrought iron, 13 000 lb. per sq. in.
For compression in wrought iron, 11 000 lb. per sq. in.
In spite of the author's remarks, it seems difficult to get around
the fact that engineers do and must design with the elastic limit in
view, and not the ultimate strength, and that the structure is unsafe
and possibly ruined when the elastic limit (or more properly perhaps,
the yield point) is passed, in tension as well as in compression. Also,
there is considerable strength beyond the yield point in compression,
which, as far as it goes, is just as valuable as the tensile strength be-
yond that limit. There appears to be a lack of data on the elastic
strength of columns. Such as the writer has been able to find, indi-
cate that the elastic strength will be found below that of test speci-
mens, but not more so than with eye-bars in tension. There also ap-
pears to be much greater danger from imperfect workmanship and
injuries to material, in the case of columns,' than in tension members,
for which reason the writer agrees with the author, that a lower unit
290 DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS [Papers.
Mr. Carpenter, should be iised ill compression than in tension, and thinks that per-
haps the ratio derived from the ultimate strength values proposed, will
be satisfactory, that is, a compression unit of about eight-tenths of the
tensile unit.
It is at this point that the writer would ask, speaking from the
viewpoint of a bridge designer, why reduce the compression value?
Why not raise the tension value ? Was not the 16 000-lb, unit chosen
with a view to increased loads, and has not the test of years proven
that railway bridges can carry, with absolute safety and without ap-
preciable deterioration, much higher stresses than the equivalent of
the 16 000 lb. ? If the question of maximum loading is settled, the
writer sees only extravagance in designing a steel railroad bridge for
the tension unit stress of 16 000 lb., the usual allowance being made
for impact and workmanship of the high standard generally required.
Neither experience with columns in structures, nor study of tests,
convince the writer that there is any cause for alarm in the use of
the 16 000-lb. compression constant in working formulas for steel
columns, unless it be that one cannot depend on having columns prop-
erly proportioned and properly detailed. An analysis of most of the
large columns which have been reported as showing unsatisfactory
strength will show that the columns were defective in design, as com-
pared with the requirements of good modern practice. The writer
thinks that the principal trouble, if any, will be found in the column
details, and that if the same attention is given to the concentric ap-
plication of loads and to rivet connections as in tension members,
ample provision is made for the full transmission of stress to all parts
of members through details, and the ratios of width and length to
thickness are kept down to the limits of conservative modern specifica-
tions, so that columns will have some body and not be "built of sheet
iron," and there will be no failures nor cause for alarm with the
16 000-lb. compression constant in columns of ordinary size and con-
struction.
It seems to the writer that, instead of being cut off on a horizontal
line for very low values of ^ , say less than 20, a formula line should
tlieoretically rise abruptly to the compressive limit of the material at
= 0. This, of course, would make a complicated formula, and, as
r
such short columns are unusual, it may be as well to omit this extra
complication. It will be noted that Mr. Worcester omitted to plat
values for columns havincr < 20, although the serie.s of tests he men-
tions includes a large nunjber of such with values which would rise to
the limits of his diagram.
In conclusion, the writer would state that he is opposed to a
Papers.] DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS 291
formula that is "chopped off" at the "long" end. Such a formula may Mr. carpenter,
be all right to design with, but it is "no good" for use in determining
the strength of existing structures. A formula which best represents
the true strength of a column, assuming its design is correct and its
physical condition is up to the average, seems to be the proper one,
and he does not know of any formula that fulfills this condition as
well as the Gordon-Rankine formula, in the form:
C
i 18, 000 \r /
Vol XXXIV. MARCH, 1908. No. 3.
AMERICAN SOCIETY OF CIVIL ENGINEERS.
INSTITUTED 185 2.
PAPERS AND DISCUSSIONS.
This Society is not responsible, as a body, for the facts and opinions advanced
in any of its publications.
EFFECT OF EARTHQUAKE SHOCK ON HIGH
BUILDINGS.
Discnssion.*
By Messrs. Guy B. Waite and E. G. Walker.
Mr. Waite. GrUY B. Waite, M. Am. Soc. C. E. (by letter). — In the paper en-
titled "Wind Bracing for High Buildings,"t the writer assumed a
horizontal wind pressure of 30 lb. per sq. ft. as acting against the en-
tire windward side of the structure. The stresses induced by the wind
force were assumed to be resisted by the construction acting as a canti-
lever. The building was assumed to be plumb. No increased bending
moment, caused from an overhang, by wind pressure was thought neces-
sary. Provided the weight of the building was sufficient to counteract
the overturning moment due to wind, the mass or weight of the build-
ing did not enter into the discussion.
The resistance of the structure to the horizontal component of
wind pressure was discussed without reference to whether it weighed
100 lb. or 1000 000 lb. Mr. Chew's first conclusion, that the stresses
produced by earthquakes are similar to those caused by wind, is mis-
leading. While the force from wind pressure is definite, and is dis-
tributed throughout the structure, the force from an earthquake is in-
definite and unmeasurable, and is distributed throughout the structure
only by acceleration taken at one place — the foundation.
To compare the two forces, it may not be improper to liken them
to the working of horizontal engines under a given pressure: the force
*This discussion (of the paper by R. S. Chew, Assoc. M. Am. Soc. C. E., printed in
Pnx-ccdiniis for January, 1908), is printed in Procecflinyn in order that the views expressed
may lip l>ioiif:clit before all members for further discussion.
ri'raii.'^dctions. Am. Soc. C. E., Vol. XXXIII, p. 190.
Papers.] DISCUSSION ON EFFECT OF EARTHQUAKE SHOCK 293
of the wind being similar to small pistons with long strokes, while the Mr. waite.
force of the earthquake is similar to a piston having an indefinitely
large area with a very small stroke. In the former case, the engine
force is distributed against the side of the building, is limited in
amount, and is substantially all taken up by the structure ; in the latter
case, the immeasurable force from the unlimited piston area is simply
carried through the foundation of the building, the only force taken
up by the building being due to the vibration of the foundation.
On the leeward side of a building the force of the wind is prac-
tically nil, while the force of the earthquake is substantially the same
on each side of the foundation. The wind force is all taken by the
building, whether it be a heavy or a light structure. The vibration of
the foundation of a building, from earthquake (other things being
equal), will be the same, whether it be heavy or light; the momentum
only will vary with its weight.
The amount of the vibration of the superstructure of the building
caused by earthquake will depend on the rapidity and length of stroke
of the so-called piston, the elasticity of the material in the construc-
tion, and the design of the building. For instance, if the foundation
of the building were divided into two horizontal parts, with roller or
ball bearings between the parts, the earth vibration could pass through
v.'ithout materially affecting the upper structure, whether heavy or
light, the only vibration being due to the friction of the bearings.
If the vibrations were sufficiently rapid, and the columns sufiiciently
long and elastic, probably little vibration would be felt, whether the
building were light or heavy.
While some structural resistance is absolutely necessary in the case
of wind — the force being definite and positive — the structural resistance
required in the case of earthquakes will depend on circumstances and
design, the force itself not being against the building.
Now, with a properly designed building, having a given mass and
a certain given vibration of the foundation, but little vibration may
be caused to the superstructure, while, with more unfavorable designs,
vibration enough to wreck the building might be caused, even if the
best of wind bracing were used.
Buildings may be definitely braced against wind pressure, but they
cannot be definitely braced against earthquakes.
A pile of brick may be laid so that it will resist wind pressure, but
will fall on account of the acceleration caused by an earthquake; this,
however, is no reason why a sober fat man cannot stand up as well as
a lean man under both earthquake and wind pressure. In Nature we
see resistances increasing with the size and weight of objects; if this
idea be carried out in buildings, we will but obey the mathematical
laws which govern the stability of all things composed of matter. The
heavier the building the more horizontal resistance it will naturally
294 DISCUSSION ON EFFECT OF EARTHQUAKE SHOCK [Papers.
Mr. Waite. have ; but the writer does not agree that the resistance should increase,
as indicated in the rational analysis from which the author draws his
conclusions.
It is generally considered that additional weight helps to distribute
wind pressures, and that the force of the wind is largely used up in
frictional and other internal work on the mass, to the relief of specific-
ally designed resistances.
When a force is set up in a building, from the vibration of the
mass composing the foundation, why should not much of this force,
which would otherwise be communicated to the braces and connections
of the superstructure, be lost in doing the internal work referred to
above ?
As buildings can be properly designed to resist wind, and can only
be designed to escape the vibration of earthquakes, it is believed that
they should be constructed so that their parts will withstand wind pres-
sures, and that they will then be amply provided to withstand earth-
quakes.
Wind pressures are very frequent, while earthquakes are very rare.
A building will have need for resistance to wind pressures several
thousand times for one possible resistance to earthquake.
There is no evidence to show that a modern wind-braced building
is not strong enough to withstand the vibration from an earthquake,
but there is considerable evidence to show that it is sufficient.
A building well designed to resist the force of the wind should
have plenty of good-sized columns. The connections and braces of
these columns to the girders should be strong and positive, and there
• shoiild be the maximum depth of connections of cross-beams and
girders to columns. All constructions composing floors, walls, parti-
tions, etc., should be capable of distributing stresses and of withstand-
ing vibrations.
It seems to the writer that reinforced concrete fulfills these condi-
tions better than any other known material. In reinforced concrete
the columns and girders have a monolithic connection throughout their
height, and, with proper design, can take stress in both directions. The
concrete, being a filling between the reinforcing steel, can take any
amount of vibration which will be conveyed by an earthquake. The
reinforcing steel is run into the columns, making a stronger connec-
tion than possible in steel and ordinary fire-proof construction.
If there be any part of a building in which concrete properly re-
inforced cannot be designed as light as, and perform the function of
resisting stresses better than, any other fire-proof material (in addi-
tion to which it preserves the steel), the writer is not aware of it.
Mr Walker E. G. Walker, Jun. Am. Soc. C. E. (by letter). — The writer has
read with very great interest Mr. Chew's paper and the analysis with
which he endeavors to arrive at the facts of the resistance of a steel-
Papers.] DISCUSSION ON EFFECT OF EARTHQUAKE SHOCK 295
framed building to earthquake shocks. At first sight it would appear Mr. Waik-er.
that this subject is not one which is susceptible of much calculation,
but, when the nature of an earthquake disturbance is considered more
closely, it at once becomes apparent that a rational analysis may easily
be made.
As Mr. Chew remarks, the effect of an earthquake is a wave motion.
The motion usually commences with small elastic earth-vibrations of
short periodicity, followed later by the shock proper, the period of
which will be much greater, from 1 to 2 sec, after which the vibra-
tions will become slower and smaller until a quiescent state is again
reached.
• This being the nature of the force acting on any structure during
an earthquake disturbance, the writer does not think that the author's
analysis, though correct and in order as far as it goes, is sufficiently
extended to take true cognizance of the initial conditions of the
problem. Mr. Chew treats his building as an elastic structure, the
foundations of which are subjected to an impact by -a seismological
wave, but he neglects the fact that this wave is followed by others at
intervals which, for a short period, may be regarded as regular.
When an elastic body is struck a blow, it tends to vibrate with its
own natural period of vibration, and the amplitude gets less and less
until the body comes to rest, the maximum distortion, and therefore,
also, the maximum stresses, occurring just after the impact. This is
the state of affairs Mr. Chew assumes.
The writer submits, however, that to treat the problem on this basis
is insufficient. The building should be considered, not as merely sub-
jected to an impact, biit as acted upon by a force the intensity of which
varies according to a regular periodic law. The building is then com-
pelled to execute forced vibrations, and, if it should happen to have
a natural period which synchronises with that of the applied force, a
resultant vibration of very large amplitude would be set up, causing
extreme stresses. On the other hand, and this, presumably is a more
common case, if the natural period of the building and that of the
impressed force are different, there would be a continuous variation of
stress in all members of the structure though the range would not be
so great.
The mathematical treatment of the problem, on these lines, though
a little complicated, only follows the orthodox method of investiga-
tions into the ordinary problems relating to vibrations. The writer had
intended to present a solution in some of the simpler cases, such as
those dealt with in the papei', but, unfortunately, the time at his dis-
posal has been insiifficient to take up the question in detail. However,
it should be possible, by treating the structure as a vertical cantilever
acted on by a periodic force, to arrive at a law of displacement for any
portion, and thus to get a value for the maximum deflection, /j , at any
296 DISCUSSION ON EFFECT OF EARTHQUAKE SHOCK [Papers.
Mr. Walker, point, as well as an accurate knowledge of the range, or extreme values
of deflection. The step from this to a calculation of the stresses in-
duced is easy and straightforward.
With regard to the author's first conclusion, it seems to the writer
that the stresses produced by a shock will be similar to those caused
by wind only in cases where the wind pressure is produced by gusts
at fairly regular intervals. The increase or otherwise of stresses men-
tioned in his second conclusion would be brought out in an analysis on
the lines the writer has mentioned, and, in calculating the scantlings
of a new structure, the extreme fiber stress allowed could be settled in
accordance with the range of stresses found.
This subject of the stresses induced in an elastic structure by
seismological disturbances is a very interesting and important one,
from both practical and theoretical standpoints. Up to the present,
rules and formulas have been mainly the outcome of observation and
experiment, rather than of deduction from the theoretical investiga-
tion; but there is no reason why the latter method should not be used;
so that, with a knowledge of the seismograms which have been recorded
from time to time, it should be possible to deduce, with a fair degree
of arccuracy, the probable stresses which would be induced by a shock,
and to provide suitably for them. The writer only regrets that he has
been unable to devote the time necessary to work out an analysis on
the lines he has endeavored to indicate.
Vol. XXXIV, MARCH, 1908. No. 3.
AMERICAN SOCIETY OF CIVIL ENGINEERS.
INSTITUTED 1852.
PAPERS AND DISCUSSIONS.
This Society is not responsible, as a body, for the facts and opinions advanced
in any of its publications.
THE USE OF REINFORCED CONCRETE IN
ENGINEERING STRUCTURES.
An Informal Discussion.*
By Messrs. M. S. Talk, Eudolph P. Miller, Eugene W. Stern,
AND H. C. Turner.
M. S. Falk, Assoc. M. Am. Soc. C. E. — A considerable number of Mr. Faik.
reinforced concrete structures have of late been described with en-
thusiasm before this Society and in the technical press; and many, if
not all, of the published descriptions make it appear that these struc-
tures have been a complete success from the time of their inception,
causing no trouble to designer, owner, or contractor.
As a rule, these descriptions cover the completed structure only,
and omit references to the difficulties and dangers encountered during
construction.
Candid statements of facts in relation to the use of reinforced
concrete are absolutely necessary at the present time; such statements
must be accurate, and should conceal nothing, so that they may serve
as guides to others who propose this construction for similar classes of
work.
Plates XL and XLI illustrate the construction of two buildings,
entirely of concrete, which were built during 1907, are now in use,
and, to any observer, would appear to be eminently satisfactory. In
neither case will the respective owners repeat their experiences, since
in both instances they have learned that different methods would have
afforded structures which could have been erected more quickly, at
less cost, and would have been fully as permanent.
* Continued from February, 1908, Proceedings.
298 DISCUSSION ON THE USE OF REINFORCED CONCRETE [Papers.
Mr. Faik. Plate XL and Fig. 1, Plate XLI, show an ice storage house, the
outside dimensions of which are 58 by 92 ft., and with a clear inside
height of 42 ft. 8 in. from the top of the basement floor to the under-
side of the roof slab. The columns supporting the roof are 18 by 12
in. in cross-section, and are embedded at intervals of about 11 ft. in
the curtain walls, which are 12 in. thick for the exterior and 10 in.
for the interior walls. The building, which is to store cakes of manu-
factured ice, contains three chambers running the full length of the
structure, the only entrance to each being through a small ice chute in
■ the front of the building. There are no windows. At first study, any
engineer would claim such a structure to be ideal for reinforced con-
crete; forms for vertical walls and for one roof slab only were re-
quired. The history of the case, however, refutes this.
The building was planned by an architect, who called for proposals,
requiring the bidding contractors to design the reinforced concrete
v/ork subject to iiis approval, although he himself wrote the specifica-
tions under which the work was to be built, and prepared preliminary
plans showing his ideas as to reinforcement. One of the requirements
was that the walls and columns were to be designed to withstand an
assumed horizontal thrust due to the pressure of the ice. Conse-
quently, the columns were designed, by the contractors to whom the
work was awarded, as vertical beams loaded at their centers with the
ice thrust. This explains (Fig. 1, Plate XL) why the reinforcing rods in
the columns were placed -in two lines parallel to the exterior faces of the
columns, instead of being spaced more uniformly throughout the cross-
section. The rods forming this reinforcement ran, for the most part,
the full height of the biiilding, and, ^as they were not self-supporting,
it was necessary to build a wooden structure to hold them before any
concreting work was done. This structure is shown in Fig. 2, Plate
XL.
The rods in the columns were hooped together at short intervals,
not only by outside wires, but also by wires crossing through the
center; moreover, in order to space the corner column rods away from
the forms, the contractor inserted plate-washers on each corner rod.
The curtain walls were also reinforced with horizontal and vertical
rods spaced and wired as shown in Fig. 1, Plate XLI. It is evident
that the reinforcement acted as a screen through which the raw con-
crete was forced to pass.
One clause of the architect's specifications read as follows :
"The centering for columns shall not be over half the height of the
building before concreting is commenced and for enclosing walls not
over 10 ft. in height, unless otherwise approved."
Although the contractor should have knovm better, he blindly at-
tempted to follow this clause. The final results of the work, taken in
PLATE XL.
PAPERS, AM. SOC. C. E.
MARCH, 1908.
FALK ON
THE USE OF
REINFORCED CONCRETE.
FrG. 1.— REINFuHC'lilJ CO.VCRETE STRrCTUKE FOR ICE STORAGE.
Fig. 2 —Scaffolding to Support Reinforcing Rods.
Papers.] DISCUSSION ON THE USE OE REINFORCED CONCRETE 399
connection with the design, are shown clearly in the photographs, and Mr. Falk.
require no explanation, except that when the forms for the lower por-
tions of the walls were stripped, the owner, mistrusting both contractor
and architect as to the safety of the work, called for engineering advice.
The structure was completed, after much difficulty, strictly accord-
ing to plan; dangerous defects were repaired so that no failure may
be expected, and surface blemishes were plastered so that anyone not
familiar with the actual construction might believe the building to be
an example to be followed.
The building shown by Fig. 2, Plate XLI, was originally designed
by an architect as a frame building to be finished in cement stucco;
but a reinforced concrete contractor convinced the owner that it would
cost but little more to make the building entirely of concrete, and he
was given the order to proceed. In fairness to the architect, it should
be stated that he was not consulted as to the building after the
original plans had left his hands.
When the structure had reached about half way to the second
story the owner began to suspect the character of the work which was
being done, and decided to complete the building by day's work in
charge of an engineer. No difficulties out of the ordinary were en-
countered until the I'oof was reached.
The building is 40 ft. square, and there are four interior columns.
The roof is a concrete slab, sloping at about 45° from the horizontal,
and is supported on the side-walls and on two concrete beams running
the length of the building and carried by the concrete columns. The
concrete in the main portion of the building had been poured very wet;
but when this mixture was placed on the sloping roof forms it refused
to stay in place. Therefore, wooden planks had to be placed on top
of this concrete in order to hold it down. This method, however, was
exceedingly difficult, as the roof was a dangerous place for the work-
men. The concrete was changed to a drier mixture, but still re-
quired the use of the outside forms. As it was impossible to lay very
much of the roof in one day, there were many joints. After the con-
crete had set so that workmen could move about without injury to it,
a surface coat of mortar, in which was incorporated a so-called water-
proof compound, was placed. This coat was colored with red oxide of
iron, so that the final surface showed a pleasing red. The surface
coat was plastered smooth, and it seemed as though all water would
be easily shed. The first rain storm, however, showed that the roof
leaked almost like a sieve. It must be remembered that this work had
been done by day's labor, and not by contract, and that there had been
absolutely no incentive for any but the best workmanship.
The speaker consulted several water-proofing companies, asking
them to water-proof the roof without destroying the color effect which
had been obtained, but not one of these companies would take the work
300 DISCUSSION ON THE USE OF REINFORCED CONCRETE [Papers.
Mr. Faik. and guarantee it for more than one year. The use of pitch or sirailar
water-proofing material was not permitted on account of the color, nor
does the speaker believe that any plastic material would stay on this
roof. It was finally decided to apply alum and soap, as in the Sylvester
process, and from its application up to the present time the roof has
shed the rain. It has not yet passed through both a summer and a
winter, and it will be interesting to note what effect the temperature
will have on a thin slab of this kind. The speaker would not advise
anyone to use a reinforced concrete roof of this kind.
Mr. Miller. RuDOLPH P. MiLLER, M. Am. Soc. C. E. — In the speaker's experi-
ence, along the line of building construction, the success of reinforced
concrete in engineering work is greatly dependent on thorough and
intelligent inspection. Many a good design has been completely de-
feated because of the lack of proper superintendence. The materials
being used at the present day in this kind of work are generally reliable,
but their improper handling has often been responsible for poor re-
sults. It is desired to call attention here to two defects that have been
of too frequent occurrence, which can be avoided by a little foresight
in the design and by intelligent supervision in the construction : First,
the displacement of the reinforcement when the concrete is placed;
and second, the formation of cavities in the concrete construction due
to complicated reinforcement.
It would seem unnecessary to call the attention of engineers to the
danger of the displacement of reinforcing rods or bars in reinforced
concrete beams. Concisely stated, if the displacement is upward, there
is a loss of strength proportionate to the amount of displacement; if
the displacement is downward, the fire-resisting qualities of the con-
struction are impaired, and ability to resist fire is one of the main
claims of superiority of reinforced concrete construction. Judging
from experience, however, it seems to be important to call the atten-
tion of engineers to the necessity of making provision for preventing
the displacement of the reinforcement. It is the speaker's opinion
that, no matter how carefully bars or rods are placed in the moulds,
or what precaution is taken in the pouring of the concrete, there can
be no assurance that the reinforcement is in its proper position when
the work is completed, unless some means have been used to prevent a
movement. The only certain method that has come to the speaker's
attention is that used in the so-called "Unit" systems, in which all
the reinforcing bars or rods in a beam (and it is equally applicable to
column construction), including the stirrups, are secured by heavy
wire clamps or other devices in such a way that their relative positions
cannot alter. By using washers or spacers the resultant frame can be
secured in the forms against a bodily displacement, and held at a
proper distance from the outer surface of the finished concrete.
PLATE XLI.
PAPERS, AM. SOC. C. E.
MARCH, 1908.
FALK ON
THE USE OF
REINFORCED CONCRETE.
Fig. 1.— Reinforcement of Walls and Columns.
/
ii
Rf IR nr
■ ■"^' If
m iir j,r
|i? rri
2 R I g I
Fig. i.— Reinforced Concrete Building.
Papers.] DISCUSSION ON THE USE OF REINFOECED CONCRETE
301
Besides assuring the correct position of the reinforcement, the use Mr. Miller.
of the unit frames greatly simplifies the superintendence of the con-
struction. It requires but a glance (comparatively speaking) to see
whether all the reinforcement is in place in the form and whether the
proper frame is in each form. The frame having been built up from
detailed drawings, previously prepared, the danger of the omission,
occasionally, of a bar or rod, of the substitution of a bar of less cross-
section, or of the use of too short a bar, is practically eliminated. (See
Fig. 1, Plate XLII.)
The frames themselves may be fabricated at the shops and shipped
to the job; or, if the operation is sufficiently large to justify it, there
may be a temporary shop on the premises. The particular advantage in
this is that the forms can be inspected and checked before they are put
in place. A sample detailed drawing from which the frames are made
is shown in Fig. 1.
Ul-3J«3J<l-2i4<-i-c->U— i-(;->U2-04>j<-2-0iJ* 3-11—
f* '■ '■ 8-0-^= ' >[-; 8^1-
U ■ 21-l-^=—
0'4^-l-(;-->i-i-l-Git<l'3>|«5^l'3ij
'^ 8^^^ '■ -]
No.of
Pieces
MATERIAL
LENOTH
WEIGHT
REMARKS
4
Rods 1 Vie Diam.
24'!"
4
.1
27'4"
Single Sockets
2
Double Sockets
4
Stirrups l"x V6 "
9'2"
L Holes punched I from each end
(i
8'10"
L
4
8' 9"
I'
4
Ties l"i li"
12"
t5
16
Clamps with Bolts
See Standard Sheet Ho.il.
Fig. 1.
Fig. 2, Plate XLII, shows another and quite satisfactory method of
securing the reinforcement in position when the style of columns used
is such as to admit of it. This is a photograph of one of the column-
girder connections in the McGraw Building, New York, recently de-
scribed* by William H. Burr, M. Am. Soc, C. E.
The second detail of construction which seems to have escaped at-
tention is the avoidance of too complicated a reinforcement. In the
disposition of the steel, care must be taken that the several elements
are not so closely spaced or so arranged as to prevent the concrete from
pouring between and around them and thus producing cavities. The
size of stone used in the aggregate should be considered in connection
with the spacing of the rods, or vice versa. When complicated rein-
*Proceedmgs, Am. t'cc. C. E., for October, 19C7.
302 DISCUSSIOX ON THE USE OF REINFORCED CONCRETE [Papers.
Mr. miler. forcement cannot be avoided, the size of the stones should be reduced
to suit the condition, or the stone should be eliminated, and mortar
should be used. All this applies particularly to column construction
and other work where the concrete must fall through considerable
height. The speaker has seen a column, the cross-section of which
was not more than 20% of its embedded area, because of the cavities
formed by the sieve-like action of the reinforcement. Ah instance of
what is meant, though not as serious as the case referred to, is shown
in Fig. 3, Plate XLII.
Mr. Stern. EuGENE W. Stern, M. Am. Soc. C. E. — ISTo Structural material in
recent years has temporarily won such enthusiastic partisanship, or
caught the public eye to such an extent, as reinforced concrete. It
may be that the reason for this is that it appeals so much to the
imagination of the layman.
It is useless to consider all the claims that have been made for it;
but one in particular should be flatly contradicted, which is that but
little special knowledge is required in the art of working in this ma-
terial, and therefore that it can be largely done by unskilled labor.
In view of the many fatal accidents which have resulted from the im-
proper use of this material, this claim is not as strongly urged as it
once was.
A matter of interest in connection with the construction of rein-
forced concrete work is that contracting firms, or those who exploit
patented or deformed bars, are largely responsible for the designs
which go into buildings to-day. They submit their own plans, based
on the use of these bars or some special method of construction, under
seme kind of guaranty as to carrying capacity, almost always without
any charge for their services. It is the speaker's experience that this
method leads to trouble, very often to a lawsuit. The client's interests
are supposed to be looked after by the contractor, but, when any trouble
happens, his interests, of course, are forgotten.
It is more than ever necessary, in the use of this material, that the
structural design and supervision of the work should be placed in the
hands of competent professional engineers who represent the owner's
interests only.
In no other material of construction is such extreme care necessary,
and such intelligent, constant and painstaking supervision required in
every part of the process.
Reinforced concrete is a valuable material for use in structures-,
and has a large field. It has its limitations, however, and often, owing
to the enthusiasm of its advocates, has been used where other ma-
terials would have answered the purpose better.
As a facing for buildings it has not proven a success, for the rea-
son that it is difficidt to obtain a pleasing surface, and ordinarily is
PLATE XLIl.
PAPERS, AM. SOC. C. E.
MARCH, 1908.
MILLER ON
USE OF REINFORCED CONCRETE.
Fig. 1.— Unit System of Frame.s.
Fig 2. — Method of Securing Reinforcement.
Fig. 3.— Cavities in Column.
Papers.] DISCUSSION ON THE "USE OF REINFORCED CONCRETE 303
more expensive than brick. In the construction of high buildings, the Mr. stern,
speaker believes that it is not as suitable for columns and girders as
steel-frame construction. For low buildings, or factory and mill build-
ings, occupying large areas in outlying districts, v/here there is plenty
of room to handle the material, it has proved a very desirable substitute
for mill-constructed buildings.
Among the favilts of reinforced concrete work is its tendency to
crack, due to the shrinkage of the concrete. The speaker has had to
deal with a number of reinforced concrete buildings, and none of these
has been free from cracks in various places. A recent case was inter-
esting: In a building there were two rows of colunms longitudinally,
dividing it into three bays. In the center, between the columns, there
were heavy girders, but, in the outside bays, for structural reasons,
there were in places light girders. The heavy girders, in shrinking,
drew the columns slightly together and the outside girders cracked in
the top flange.
The illustrations shown by Messrs. Talk and Miller are interesting
in showing what actually happens in practice. The speaker, however,
has seen much larger voids in columns than any of those illustrated.
In one case, where deformed bars having prongs were used, there were
voids in the columns which practically occupied the whole area of the
column. There was no attempt on the part of the contractor to scamp
his work, but the interlacing of the prongs formed a screen which held
up the stone and prevented it from becoming well consolidated in the
mixture, with the above result.
The use of reinforced concrete for railroad bridges does not seem
to be a proper application, for the reason that constant vibration would
tend to cause cracks ultimately, and separate the reinforcement from
the concrete.
Where conditions would be favorable to the rusting of steel, rein-
forced concrete is not suitable, unless cracking can be prevented, as
otherwise the reinforcement will ultimately rust out.
Mathematical investigations have been carried to an extreme degree
of refinement in reinforced concrete construction, and designs have
been worked out on paper for huge structures that stagger the imagina-
tion of any but the most enthusiastic. Only recently, a design for a
bridge over Spuyten Duyvil Creek, New York City, has been prepared
by its Department of Bridges, involving the construction of a rein-
forced concrete arch of Y03 ft. span.
Keinforced concrete is anything but an academic proposition. It
is eminently a practical one. Theorists assume for their computations
certain conditions, some of which may be possible, and some of which
may not be possible, to obtain in the practical operation of construc-
tion. Many things in the practical use of this material have yet to be
understood, and these can only be learned by experience.
304 DISCUSSION ON THE USE OF EEINFOKCED CONCRETE [Papers.
Mr. Stern. Has the state of the art, in the use of this comparatively new ma-
terial, progressed to such an extent as to warrant the conclusion that,
to-day, it is a perfectly safe and legitimate proposition to undertake
to build structures, which in magnitude and boldness of conception far
exceed anything in existence of similar type? Is it not sounder engi-
neering to progress slowly along well-tried-out lines?
There is wide difference of opinion as to what the working stresses
ought to be, particularly in compression. The building codes of the
various cities in America are not by any means uniform in this re-
spect, the allowable unit stresses in compression varying from 350 lb.
upward, and some engineers have recommended as high a stress as 750
lb. per sq. in.
There have been a great many tests on concrete cubes, the data
obtained from which are valuable in this discussion. The highest re-
sults have been obtained, of course, where the specimens have been
kept in moist sand, or submerged under water; but tests made under
such ideal conditions, which rarely obtain in practice, should not be
used as a basis for deciding what should be the working stress of con-
crete in compression, unless these conditions approximate those under
which the structure itself is built.
Among the many tests made at Watertown Arsenal, the speaker
would refer especially to a series of tests on 12-in. cubes, prepared by
the authorities at the Arsenal, the results of which are given in their
Annual Reports for 1899 to 1904. These blocks were allowed to set
in air, and were stored in a dry, cool building throughout the period of
the tests, which were made after periods ranging from 3 months to
5 years. The conditions under which the blocks were stored would be
almost identical with those to which reinforced concrete work in build-
ing construction would be exposed, and these tests, therefore, would
give results more in harmony with actual conditions than those in
which the blocks were immersed in water or kept moist in sand for a
number of months.
The average of 10 tests, after ■> months, was 1 958 lb. per sq. in.
" " 16 " " 4 " " 2 244 "
" 16 " •' 1 year, " 3 330 "
" 15 "■ " 2 years, " 2 610 "
u -^5 u u 3 .. a 2 610 "
u -^0 " " 4 " " 2 960 -
a 2 " "5 " " 2 630 "
Disregarding the 3-month and 4-month tests, the average of 58
tests, after 1 to 5 years, was 2 870 lb. per sq. in. These blocks were all
made of 1 part Alpha Portland cement, 2 parts sand and 4 parts
broken trap rock, varying in size in the different specimens from i in.
to 2^- in.
Papers.] DISCUSSION ON THE USE OF REINFORCED CONCRETE 305
It will be noticed that the 2-, 3-, 4-, and 5-year tests show sub- Mr. stem,
stantial reductions in strength from the 1-year tests, and the records
show, also, that there was a considerable loss of weight, varying from
i lb. to 2 lb. in each block.
There will undoubtedly be differences of opinion as to what fraction
of the ultimate strength should be adopted for a safe working stress.
To compensate for the great factor of ignorance which exists in the
construction of concrete and reinforced concrete work, there should be
an ample margin of safety. No matter what care may be taken with
the sampling and storing of cement, it is practically impossible, in the
process of construction, to prevent, not only some of the material
losing its strength, but also to obviate defects in workmanship.
It has been considered for many years that a factor of safety of
from 10 to 20 should be used in masonry. The speaker sees no reason,
therefore, why a greater load than J to ro of the ultimate strength of
laboratory tests on concrete cubes should be used in practice in build-
ing construction, which would give between 290 and 360 lb. per sq. in.
as a unit stress.
Professor Burr has brought up the question as to whether or not
the Watertown tests quoted by the speaker were all made under uni-
form conditions and with the same brand of cement and other ma-
terials. As far as can be learned from the official reports of these
tests. Alpha Portland cement was used throughout, and the same quality
of sand and stone ; moreover, the specimens were stored under the same
conditions, throughout the years during which the tests were conducted.
H. C. Turner, Assoc. M. Am. Soc. C. E. — During this discussion, Mr. Turner,
a number of questions have been raised which call for an answer by
those who are closely identified with the construction of reinforced
concrete buildings.
In answer to Mr. Stern's question regarding the preservation of the
steel reinforcerbent in concrete structures, the following is the experi-
ence of the Turner Construction Company in razing a one-story build-
ing, erected for the J. B. King Company, at New Brighton, Staten
Island, in 1902, which was taken down during the summer of 1907 to
make room for a larger structure: The building had reinforced con-
crete walls, 9 in. in thickness to grade line and 5 in. in thickness from
grade line to roof line, reinforced concrete interior columns, 11 in.
square, and reinforced concrete beams, girders and roof slab. The
foundation consisted of spruce piling, cut off at mean tide and capped
with reinforced concrete. All steel reinforcement was found in per-
fect preservation except a few i-in, hoops in the wall columns, which
were within i to i in. of the surface. These showed slight corrosion,
which would indicate that it is important to secure all steel reinforce-
ment at least | in. from the exterior surface. The steel in the footings.
30G DISCUSSION ON THE USE OF REINFORCED CONCRETE [Papers.
Mr. Turner, although alternately wet by the tide each day, was in perfect condition.
In some cases this steel was within | in. of the surface.
Numerous observations of a similar kind have been made by engi-
neers, and it is now generally recognized that steel reinforcement is
permanently preserved in concrete structures.
It seems unfortunate that illustrations of standard reinforced con-
crete work have not been shown, rather than those of generally defective
work, although such illustrations are valuable in indicating the charac-
ter of design and workmanship to be avoided. It must not be assumed,
however, that they are typical of reinforced concrete construction.
Much excellent work is being done in New York City, and in nil
cities in the United States. Eight and ten-story buildings are not
unusual, and it is to be noted that these buildings have proven espe-
cially adaptable for heavy storage or heavy manufacturing.
As Mr. Miller has stated, it is perhaps more difficult to secure good
workmanship than good engineering design. This is a matter of or-
ganization. Good workmanship should be required, and undoubtedly
can be furnished. There is abundant evidence of this, and good work-
manship costs but little more than poor workmanship. It is necessary
to have a thorough and experienced organization of workmen ; but this
is just as true in any line of successful business.
Regarding safe unit stresses, there is no reason for a factor of
safety of ten. Reinforced concrete buildings have a larger factor of
safety than steel buildings, because of the monolithic character of the
construction. Concentrated loads are distributed over larger areas
because the reinforcement extends in both directions. Vibration is
largely reduced. This is well demonstrated in the Ketterlinus Build-
ings, in Philadelphia. The two buildings are about the same size, 8
stories in height; one has a steel frame with hollow tile floors and
brick walls; the other, and later, building has reinforced concrete
columns, beams, girders and floors, with brick veneer walls. Both
buildings are used for printing and lithographing, and are subjected
to practically the same floor and machinery loads. The vibration in
the concrete building is very noticeably less than in the steel-frame
building, in fact, it can hardly be detected.
In the Robert Gair Company Building, in Brooklyn, there is a
16-ton embossing machine set on a 3 by 6-ft. base in the middle of a
bay on the seventh floor. No deflection has occurred in the beams,
and, when the machine is in operation, no vibration is perceptible,
although the working loads assumed for this building were only 200
lb. per sq. ft.
Answering Mr. Miller's observatioiis on the value of unit systems
in reinforced concrete construction, the chief objection to them at
present is the additional cost, which must be paid by the owners.
Fnit frames may relieve the architect or engineer of some anxiety
Papers.] DISCUSSION ON THE USE OF REINFOECED CONCUKl'l'; 307
and responsibility, but it is admitted that most of the important work M''- Turner,
in the United States has been done with the loose-bar system; and,
with a proper organization, loose bars, so-called, can be placed and
secured in the work with absolute reliability. The owner looks for
results, and should certainly be entitled to the difference in cost be-
tween buildings constructed with loose-bar systems and with unit
systems.
308 MEMOIR OP CALVIN EASTON BRODHEAD [Memoirs.
MEMOIRS OF DECEASED MEMBERS.
Note.— Memoirs will be reproduced in the volumes oi: Transactions. Any information
which will amplify the records as here printed, or correct any errors, should be forwarded
to the Secretary prior to the final publication.
CALYIN EASTON BRODHEAD, M. Am. Soc. C. E.*
Died April 29th, 1907.
Calvin E. Brodhead was born in Pike County, Pennsylvania, on
December 27th, 1846. His family moved to Mauch Chunk, Pennsyl-
vania, in 1851. He attended school at vphat vs^as knov^n at the time as
Park Seminary, and at St. Mark's Parish School, where Felix Ansart
was Principal. During vacation periods, he worked in the blacksmith
shop of N. Eemmel and Company, who repaired cars for the old
Beaver Meadow Railroad. When the survey was made for the railroad
from Bethlehem to Bath, Pennsylvania, about 1862, he found employ-
ment on the engineer corps, and chose engineering as his profession.
After the great flood of 1862 in the Lehigh River, which destroyed the
canal above Mauch Chunk, he entered the service of the Lehigh Valley
Railroad, locating the line over Wilkes-Barre Mountain, between Penn
Haven and White Haven. On this work he met the late Sidney Dillon,
F. Am. Soc. C. E., and a friendship was formed which lasted until
Mr. Dillon's death.
After the Lehigh Valley Railroad was opened to Wilkes-Barre, Mr.
Brodhead moved farther up the line to what was known as the Pennsyl-
vania-New York Canal and Railroad. About 1871 he was transferred
from Wilkes-Barre to Bethlehem, Pennsylvania, and, as Principal As-
sistant Engineer, under the late Robert H. Sayre, Chief Engineer,
commenced locating the Easton and Amboy Railroad. He remained
with the Lehigh Valley Railroad until 1877. During the building of
this line (Easton and Amboy) the construction of the Musconetcong
Tunnel was directly under Mr. Brodhead's charge.
From 1877 until 1883 he was engaged in the lumber business, and
then he formed a partnership with Lafayette Lentz, of Mauch Chunk,
John Byron and Daniel C. Hickey, of Mt. Vernon, New York, and
engaged in the contracting business. The first contract of the new
firm was for about ten miles of very heavy work on the Southern
Pennsylvania Railway in Fulton County, Pennsylvania. In 1885 the
firm secured the contract for the Vosburg Tunnel for the Lehigh Valley
Railroad. In 1887 the firm of Brodhead and Hickey succeeded Lentz
and Company, and while connected with this firm Mr. Brodhead was
engaged on several large undertakings, notably the Palisade Tunnel
for the New York, Susquehanna and Western Railroad, and a portion
*Memoir prepared by F. H. Clement, M. Am. Soc. C. E.
Memoirs.] MEMOIR OF GEORGE THOMAS NELLES 309
of the Pittsburg, Bessemer and Lake Erie Railroad, and the Lehigh
Valley Railroad. After the death of Mr. Hickey, in 1894, the firm
name was changed to C. E. Brodhead and Brother, and subsequently
to the Brodhead Construction Company, under which name the firm
continued work until Mr. Brodhead's death. It was in the contract
business that Mr. Brodhead spent the most active part of his life, and
in that he was best known and most successful. He was a man of
quick ideas, and was a born locating engineer, in which capacity he
was frequently called in consultation.
Mr. Brodhead continued to be interested for many years in the
coal and lumber bvisiness, having large interests in Kentucky. He
was twice married, and three children by his first wife survive him.
Mr. Brodhead was elected a Member of the American Society of
Civil Engineers on February 21st, 1872.
GEORGE THOMAS NELLES, M. Am. Soc. C. E.
Died November 15Tir, 1907.
George Thomas Nelles, son of George W. Nelles and Virginia Hobbs
Nelles, was born on April 15th, 1856, in Muscatine, Iowa.
His boyhood was spent in Leavenworth, Kansas, to which place his
parents moved in the summer of 1857. Mr. Nelles prepared for college
in the private school of the Reverend (now Bishop) John Mills Ken-
drick, and was graduated from the Rensselaer Polytechnic Institute
with the degree of C. E. in June, 1877.
After a few months' work as instrumentman with the United States
Engineer Corps at Leavenworth, he entered the service of the Kansas
City, St. Joseph and Council Bluffs Railway, as Assistant Engineer
in charge of surveys and relocation.
In the summer of 1878 he re-entered the Government service, as
United States Assistant Engineer, on the Missouri River improvement,
having in charge at various periods the work at Atchison, St. Joseph,
and Leavenworth, until the spring of 1883 when he was elected City
Engineer of Leavenworth, Kansas. Entering upon his duties at a time
when the city was growing rapidly, he directed much public work,
supervising, during his term of office, the expenditure of more than
$1 250 000 in grading and paving streets and constructing sewers, cul-
verts, and bridges.
During his term of six years as City Engineer, Mr. Nelles was also
Consulting Engineer for the Western Home for Disabled Volunteer
Soldiers; Chief Engineer of the Riverside Coal Company; Chief En-
♦Memoir prepared by F. E. Bissell, M. Am. Soc. C. E.
310 MEMOIR OF GEORGE THOMAS NELLES [Memoirs.
gineer of the Leavenworth Rapid Transit Company; and Chief Engi-
neer of the East Omaha Land Company,
At the organization of the Nebraska and Colorado Stone Company,
in 1889, Mr. Nelles became its Secretary and Manager. The company
operated quarries in Nebraska and Colorado, contracting not only to
furnish stone, but, also, in many cases, for the complete erection of the
structure.
Severing his connection with the Stone Company in 1891, he en-
tered the general contracting business, constructing sewers, pavements,
bridges, water-works and river and harbor improvements. The largest
and most important contracts handled during the four years he spent
in this work were the construction of the sewers in Denver, Colorado,
and the harbor improvements in the Mississippi River at St. Louis,
Missouri.
In the spring of 1895 Mr. Nelles again entered the Government
service as U. S. Assistant Engineer, on the Tennessee River improve-
ment at Chattanooga, Tennessee. During his six years of service on
the Tennessee River and its tributaries, many important and difficult
problems presented themselves. He made a careful study of the con-
struction of locks and dams under the conditions of fluctuating velocity
of current and volume of discharge which there prevail. His reports
on all subjects assigned to him were always exceedingly full and com-
plete. He prepared detailed tables showing the cost of construction of
the lift and gtiard locks at Colbert Shoals, Alabama. He investigated
the discharge of the Tennessee River, checking the formulas with the
actual measured velocities, and determining for this stream the
value of n, in Kutter's formula. His solution of the problem of the
effect of a dam on a submerged discharge, and on the surface level
of the upper pool, reached in his study of projects for the improve-
ment of that part of the Tennessee River known as the "Suck," is a
material addition to engineering knowledge.
Mr. Nelles studied the conditions on the French Broad River, and
made plans for widening and deepening the channel ; he examined and
reported on the necessity of making any improvement of Powells
River; made plans and estimates for the low-water improvement of
the Hiawassee, Little Tennessee, and Clinch Rivers, and also reported
on the feasibility of making improvements on the Holston River.
The same careful attention to details, and a comprehensive con-
sideration of all the component parts of the subject, characterize each
of these reports. They show that rare combination, complete theoreti-
cal knowledge and practical ability.
In June, 1901, Mr. Nelles was transferred to Cleveland, Ohio, as
U. S. Assistant Engineer in charge of the improvements of the harbors
on Lake Erie at Cleveland, Lorain, and Fairport. The same thorough-
ness and attention to detail, combined with indomitable energy and
great administrative ability, characterized his work there.
Monioirs.] MEMOIR OF HERBERT FRANKLIN NORTHRUP 311
The earnestness with which he worked, the ability which he brought
to the work, and the honesty of his dealings, combined with his cheer-
ful disposition, made him a very companionable man, both socially and
professionally.
His health began to fail in 1903. Two surgical operations failed to
give more than temporary relief, and he died at Cleveland, Ohio, on
November 15th, 1907.
On February 15th, 1884, Mr. Nelles was married to Miss Lena
Ralston, who, with one son, survives him.
Mr. Nelles was a Member and a Director of the Civil Engineers'
Club of Cleveland. He was elected a Member of the American Society
of Civil Engineers on October 3d, 1888, and contributed to the Trans-
actions a discussion* on the paper by the late George W. Rafter, M.
Am. Soc. C. E., entitled "On the Flow of Water over Dams ;" and also
a discussionf on the paper by the late R. C. McCalla, M. Am. Soc.
C. E., entitled "Improvement of the Black Warrior, Warrior, and
Tombigbee Rivers, in Alabama."
HERBERT FRANKLIN NORTHRUP, M. Am. Soc. C. E. |
Died January 21st, 1908.
Herbert Franklin Northrup, born on a farm near Shoreham, Ver-
mont, on October 9th, 1850, was the youngest child of Nazro and Mary
Hawes Northrup.
After attending the village school he prepared for college in Kim-
ball Union Academy, and entered Middlebury College, Vermont, in
the class of '73. He next taught mathematics and English for two
years at a boys' .school in Flushing, Long Island. He then took a
graduate course in engineering, in Sheffield Scientific School, Yale, in
the class of '78.
His first engineering engagement was upon the Lake Champlain
breakwater at Swanton, Vermont, in 1878, and in 1879 he was engaged
on railroad maintenance work at Salem, Massachusetts. In the spring
of 1880 he entered the employ of the Texas Pacific Railroad as As-
sistant Engineer of construction, and was located at Fort Worth, Texas.
He continued in .the employ of that company, in responsible positions,
until the completion of its construction in 1885.
On February 2d, 1882, he was married to Miss Cornjelia F. Allan,
of New Haven, Connecticut.
* Transactions, Am. Soc. C. E., Vol. XLI V, p. 359.
t Transactions. Am. Boc. C E., Vol. XLIX. p. 384.
t Memoir prepared by J. J. McVean, M. Am. Soc. C. E.
312 MEMOIR OF HERBERT FRANKLIN NORTHRUP [Memoirs.
He entered the employ of the Missouri Pacific Railroad Company
in 1885, as Assistant Engineer of construction in Missouri and Kansas,
and in September, 1886, he engaged with W. V. McCracken and Com-
pany, Contractors, as Chief Engineer on the construction of railroads
in Ohio and Indiana. From August to November, 1887, he was en-
gaged as Locating Engineer on the Duluth, South Shore and Atlantic
Railway, in the northern peninsula of Michigan.
In November, 1887, the writer engaged him as engineer in charge
of preliminary and location surveys for the Chicago and West Michi-
gan Railway, from Baldwin to Traverse City, Michigan, 75 miles,
which was finished in June, 1888. He was then engaged until June,
1889, upon some construction work* in the East, when he again returned
to take charge of the construction of the road from Baldwin to
Traverse City, following which he had charge of the location and con-
struction of an extension of about 90 miles from Traverse City to
Petoskey, Michigan, which was completed in 1893. In 1893 and 1894
he was engaged with the Detroit, Bay City and Alpena Railroad, and
from 1895 to 1901 was in private practice and City Engineer of
Traverse City, Michigan, and designed a proposed water supply for
that city. During this time he also located several miles of road for
the Lake Superior and Ishpeming Railroad Company.
In 1902 he entered the employ of the Cleveland, Cincinnati,
Chicago and St. Louis Railroad Company, in charge of a residency on
the relocation and construction of its line for double track, and reduc-
tion of grades and curvature, where he had charge of some very diffi-
cult and heavy work, especially the construction of several large-span
concrete arches.
In May, 1905, he formed a partnership with the writer, as Consult-
ing Engineers, with office at Grand Rapids, Michigan, where he was
engaged until his death.
Mr. Northrup was beloved by all who knew him. He was of a
very modest and retiring disposition, amiable, a staunch friend, and a
thoroughly honorable business man. Quiet and even-tempered, honest
in all his dealings, he had not only the entire confidence of his em-
ployers, but also the love and friendship of his assistants.
One of his many assistants, now occupying a responsible position
with the City of Buffalo, says "I knew him as a gentleman and an en-
gineer, and nothing can be added to that. His even temper and kindly
ways always left a pleasant recollection."
His death was very sudden and unexpected; after a severe fall on
an icy sidewalk, he was attacked with prostatitis, necessitating an
operation from which he did not rally.
Mr. Northrup was a Royal Arch Mason, a member of the Delta
Kappa Epsilon College Fraternity, and was elected a Member of the
American Society of Civil Engineers on January 6th, 1892.
Memoirs.] MEMOIR OF WILLIAM ROBERTS 313
WILLIAM ROBERTS, Assoc. Am. Soc. C. E.*
Died December 28th, 1907.
William Roberts was born in Watertown, Massachusetts, on March
25th, 1835. He was a son of John Roberts, a descendaoit of one of the
old Boston families. His x^arents moved to Waltham soon after his
birth, and he attended the Waltham Public Schools, the private school
of Daniel French, and the Allen School of Newton.
He entered the employ of the Boston Manufacturing Company, in
the machine shop, as a start toward the development of his mechani-
cal genius. Obtaining permission from the Fitchburg Railroad, he
ran an engine from Waltham to Boston a number of times. He then
went to Virginia, where he studied at the establishment of the Norfolk
Manufacturing Company. When very young he entered the United
States Navy. He was Third Assistant Engineer under Commodore
Perry when he opened the Ports of Simoda and Hakodadi, in Japan,
and served on the Michigan, on the Great Lakes in 1856, and on the
steam frigate Roanoke, on the Coast of Central America in 1857. He
was one of the officers on the steamer Fulton which captured Walker,
the filibuster, in 1858, and he served on the Memphis on the Paraguay
expedition in 1859.
In July, 1858, Mr. Roberts was promoted, becoming Second As-
sistant Engineer, and one year later he was made First Assistant. He
resigned in September, 1859, but, in response to his country's call, re-
enlisted in the Navy in April, 1861. In 1863 he became Chief Engi-
neer.
During the attacks on the forts and batteries at Pensacola Bay, in
1861, he was on the frigate Niagara; the steam sloop Housatonic
carried him to a point off Charleston, in 1862, when she drove
two iron-clad rams into port. He was attached to the frigate Niagara
repairing at Charlestown Navy Yard, during 1863 and 1864.
After his retirement from the Navy he returned to Roberts' Cross-
ing, Waltham, and joined his father in the manufacture of paper, and,
even after his father's death, he carried on the business under the firm
name, John Roberts and Son.
The manufacture of roofing paper was the principal product of the
mill until his ever-active mind turned to the then new article, asbestos,
and his mill was the first to produce asbestos fire-proof paper, the secret
of the process being held by him for many years.
He declined the acceptance of public office, notwithstanding the
many entreaties on the part of his friends. The only State positions
he held were Commissioner on Prisons, and Representative to the
*Menioir prepared by Sumner Milton, Esq.
314 MEMOIR OF WILLIAM ROBERTS [Memoirs.
General Court. He was a staunch Republican, and was sent as a
delegate to the State Convention for many years. He was a Member
of the Waltham Board of Cemetery Commissioners, and a Director of
the Waltham National Bank.
Mr. Roberts was a life member of Monitor Lodge, A. F. and A. M.,
and Post 29, G. A. R., of Waltham. He belonged to the Military Or-
der of the Loyal Legion of the United States, also the American So-
ciety of Mechanical Engineers.
"He serves God well, who serves his creatures," truly speaks the
life of William Roberts. Never was he known to refuse to help a
worthy person or project. Many leave public bequests and are thought
generous, but Mr. Roberts' method was to give continuously; and, as
was his nature, quiet, just, liberal, honest, and philanthropic, so was
his giving, and there are many individuals and institutions who miss
his beneficence.
Mr. Roberts was an interesting conversationalist, having toured the
world. He was especially interested in the ocean, and crossed the At-
lantic on all the finest new steamers, his knowledge of mechanical en-
gineering enabling him to note all the latest improvements in the
engines. It was difficult, indeed, to ask a question on country or prod-
uct on which Mr. Roberts could not give valuable information, and in
such a simple manner that a child could enjoy his talk.
On October 27th, 1879, Mr. Roberts married Eva C, daughter of
Hon. Gideon Haynes, and their home was always at Waltham, His
married life was one of devotion, and it would be difficult to decide
whether the palm should be given to him or to his companion in life.
William Roberts was elected an Associate of the American Society
of Civil Engineers on June 4th, 1884.
If 1-? %
>»>;», i:>;i.;li»il,»i'i»;.
; M'
If 14 i« »«
i> n !#.
i^ t* u 1» t
1. ft'^ir'- Ik' aw ' A^
^TSSING
VOLUME S )
ISSUE#
MONTH
YEAR I'^Oh
r
% m
^-.i •M»'j)!;ji5J}»J»«.M}«M".M>i'1j
[« It Hw
iv i» «^ 1
Vol. XXXIV
MAY, 1908.
No. 8.
AMERICAN SOCIETY OF CIVIL ENGINEEES
1 N S T 1 T L' T E L) 18 5 3
PAPERS AND DISCUSSIONS
riiis Sofiety is n'>t i-espousible, as a body, for the facts aud opinions advaiict»d
in any of its publications.
CONTENTS
Papers : paoe
I'lirve Resistance in Water Pipes.
By Ernest W. Schoder, Assoc. M.Am. See. C. E 416
Not«s Upon Docks and Harbors.
By Li'THER Wagoner, M. Am. Soc. C. E 446
Discussions :
The Flood of March, 1907. in the Sacramento and San Joaquin River Basins,
California.
By Messrs. Luther Wagoner, H. H. Wadsworth and George L. Dillman 460
Erection of the Bellows Falls Arch Bridge.
By F. W. Skinner, M. Am. Soc. O. E 46H
Safe Stresses in Steel Columns.
By William Cain, M. Am. Soc. C. E 477
The ElectriflcatioD of the Suburban Zone of the New York Central and Hudson
River Railroad in the Vicinity of New York City.
By Messrs. Edwin B. Katte. W. S. Murray. George A. Harwood, W. B. Pot-
ter, Frank J. Sprague, Henry G. Stott, and William J. Wilgus 484
Recent Developments in Pneumatic Foundations for Buildings.
By Messrs. F. W. Skinner, T. Kennard Thomson, and Louis L. Brown 521
Memoirs:
Charles Haynes Haswkll, Hon. M. Am. Soc. 0. E 534
James Dun. M. Am. Soc. C. E 537
XLVI.
XLVII.
XLVIIl.
XLIX.
L.
LI.
LIl.
LIU.
LIV.
LV.
LVI.
LVII.
LVIII.
LIX.
LX.
LXI.
LXII.
LXIII.
LXIV.
LXV.
PLATES
Experimental Pipe Line at Cornell University Hydraulic Laboratory; Nozzle
and Curves 419
Diagram Showing Results of Experiments on Curve Resistance in Water
Pipes 423
Statistical Chart Showing the Progress of Banking, Commei-ce, Shippintf,
Population, etc 449
Erection of Eads and Washington Bridges 469
Erection of Niagara Railway and Highway Arches 471
Erection of the Kaiser Wilhelm Bridge 473
Erection of the Garablt Viaduct and the Bonn and Diisseldorf Bridges 475
Erection of the Fairmount Park and the Rochester Driving Park Bridges. . 477
Erection of the Lake Street and Panther Hollow Bridges 477
Erection of the Kornhaus Bridge 477
Plans, etc., of Main Steam Piping in Power-Stations 485
General Diagram of Connections, Poit Morris Power-Station 487
Plans of Port Morris Swit<h-House 489
Sections. Port Morris Switch- House 491
Wiring Diagram, Typical Sub-Station 493
Diagram of Positive Feeders, N. Y. C. & H. R. R. R. Electrification 495
Cross-Section. Removal of Grand Central Train-Shed 497
Traveler for Removal of Grand Central Train Shed ' 499
Views Showing Removal of Grand Central Train-Shed . 501
Appliances used in Caissons for Foundations of Buildings 523
V^ol. XXKIV MAY, 1908. No. S.
AMERICAN SOCIETY OF CIVIL ENGINEERS
1 N S T 1 T I' T K I) 1 8 .5 -2
PAPERS AND DISCUSSIONS
This Society is ii'it respansible, as a body, for the facts and opinions advanced
in any of its publications.
CONTENTS
Papers : page
Curve Resistance in Water Pipes.
By Ernest W. Schoder, Assoc. M. Am. Soc. C. F, 416
Notes Upon Docks and Harbors.
By Luther Wagoner, M. Am. Soc. C. E 446
Discussions :
The Flood of March, 1907. in the Sacramento and San Joaquin River Basins,
California.
By Messrs. Luther Wagoner, H. H. Wadsworth and George L. Dillman 460
Erection of the Bellows Falls Arch Bridge.
By F. W. Skinner, M. Am. Soc. C. K 468
Safe Stresses in Steel Columns.
By William Cain, M. Am. Soc. C. E 477
The ElectriflcatioD of the Suburban Zone of the New York Central and Hudson
River Railroad in the Vicinity of New York City.
By Messrs. Edwin B. Katte. W. S. Murray, George A. Harwood, W. B. Pot-
ter, Frank J. Sprague, Henry G. Stott, and William J. Wilgus 484
Recent Developments in Pneumatic Foundations for Buildings.
By Messrs. F. W. Skinner, T. Kennard Thomson, and Louis L. Brown 531
Memoirs :
Charles Haynes Haswell, Hon. M. Am. Soc. C. E 534
James Dun. M. Am. Soc. C. E 537
PLATES
XL VI. Experimental Pipe Line at Cornell University Hydraulic Laboratory; Fozzle
and Curves 419
XLVII. Diagram Showing Results of Experiments on Curve Resistance in Water
Pipes 423
XLVIIl. Statistical Chart Showing the Progress of Banking, Commerce, Shipping,
Population, etc 449
XLJX. Erection of Eads and Washington Bridges 469
L. Erection of Niagara Railway and Highway Arches 471
LI. Erection of the Kaiser Wilhelm Bridge 473
LII. Erection of the Garabit Viaduct and the Bonn and Diisseldorf Bridges 475
LIIl. Erection of the Fairmount Park and the Rochester Driving Park Bridges. . 477
LIV. Erection of the Lake Street and Panther Hollow Bridges 477
LV. Erection of the Kornhaus Bridge 477
LVI. Plans, etc., of Main Steam Piping in Power-Stations 485
LVIl. General Diagram of Connections, Port Morris Power-Station 487
LVIII. Plans of Port Morris Swit.h-House 489
LIX. Sections, Port Morris Switch- House 491
LX. Wiring Diagram, Typical Sub-Station 493
LXI. Diagram of Positive Feeders, N. Y. C. & H. R. R. R. Electrification 495
LXII. Cross-Section. Removal of Grand Central Train-Shed 497
LXin. Traveler for Removal of Grand Central Train Shed ' 499
LXI V. Views Showing Removal of Grand Central Train-Shed . 501
LX V. Appliances used in Caissons for Foundations of Buildings 523
418 CURVE RESISTANCE IN WATER PIPE [Pai)crs.
straight line composed of six pipe lengths was set up in the pipe alley
alongside the large canal of the Cornell University Hydraulic Labora-
tory. The pipes were flange-connected. The total length of 6-in.
pipe was 122 ft. The loss of head was measured in a length of 99.33
ft., a length of 20.04 ft. being allowed up stream from the first
piezometer for the disturbances due to entry from a 12-in. header to
die down. The piezometers consisted each of two diametrically op-
])osito holes in the pipe wall into which i-in. T-handle cocks were
screwed. A three-way connection served to join the short hoses from
these cocks and the single long hose to the gauge. A water differential
gauge was used to measure the loss of head. A calibrated concrete
measuring tank, of 500 cu. ft. capacity, received the discharged water
from a 4-in. pipe with a 4-in. regulating valve through which the 6-in.
line discharged. An instantaneous diverter deflected the discharge into
the tank or allowed it to run to waste, as desired. The measurements
lasted from 5 to 10 min., the time being accurately taken. Fig. 1.
Plate XL VI, is a photograph showing the pipe line. The results of
these measurements are given in Table 2, where data from later
straight pipe experiments are given also.
After this the pipes were marked, disconnected, and transported
to the bottom of the Fall Creek Gorge, in Ithaca, near the hydro-
electric plant of Cornell University. Here the curve experiments
were performed. Fig. 2, Plate XL VI, is a photograph of this plant
and Fig. 1 is a plan of the pipe line.
The pipes composing the experimental portion of the line were the
same, and were set up in the same order as when tested as a straight
pipe line. The curves were placed between Pipes Nos. 1 and 2, the
two up-stream pipes in the experiments described above, and as shown
by Fig. 1. The down-stream tangent portion thus consisted of Pipes
Nos. 2, 3, 4, and 5. Pipe No. 6 was not used for the curve experiments
because this would have brought the end of the pipe line out into the
creek.
At the discharge end of Pipe No. 5 there was attached a brass
nozzle for measuring the velocity in the pipe line. This nozzle is
shown by Fig. ?>, Plate XLVI. It had been calibrated previously by
tank measurements in the Hydraulic Laboratory. The average dis-
charge coefllcient from 40 experiments, with pressure heads at the
base of the nozzV^ ranging from 1.G49 to 50.208 ft., was found to be
0.9S8.
PLATE XLVl.
PAPERS, AM. SOC. C. E.
MAY, 1908.
SCHODER ON
CURVE RESISTANCE IN WATER PIPES.
Fig. 1.— Six-Inth Cipk I.ink < ai- iiii; Kight)
AS Set Up for First Straight-
Pipe Experiments.
Fig. 3.— Cornell University Hydro-
Electric Power Plant, and 6-In.
Pipe Line for Curve Experiments.
Fig. 3.— Nozzle at End of 6-In. Pipe Line.
Fig. 4.— Six-Inch, 90" Curves, Nos. 1 to 12.
Papers.]
CURVE RESISTANCE IN WATER PIPE
419
The lengths of the pipes, from face to face of flanges, are given ixi
Fig. 1; the following are the inside diameters — the means of four
measurements, two at each end:
Pipe No. 1.
6.106 in.
No. 2.
6.086 in.
No. 3.
6.102 in.
No. 4.
6.078 in.
No. 5.
6.072 in.
No. 6.
6.083 in.
Pipe No. 5
— 22;i»:!0-ft7-
Down-st i-L-am
Piezometer
Pipe No. t
—22.218 ft-
Pipe No. 3
— 19::J50ft
Pipe No. 2
-20.GG0-ft—
PLAN OF
6-INCH WROUGHT- IRON
PIPELINE,
AS USED IN
CURVE EXPERIMENTS
Up-stream-
Piezometer
oS5
CO
3 .5
Fig. 1.
The Curves. — The curves used were made to order, except that
Nos. 10 and 12, respectively, were standard "long sweep" and "short
turn" 6-in., cast-iron, flanged, 90° elbows. Curves Nos. 1 to 6, in-
clusive, were bent from 6-in. wroiight-iron pipe. Curves Nos. 7 to 12,
inclusive, were of cast iron. All were 90° curves; and all were left
uncoated.
The wrought-iron pipe curves had al)out 6 in. of straight pipe at
each end. The ends had been threaded to receive standard flanges.
The cast-iron curves were flanged, faced, and drilled complete, ready
for setting up. Fig. 4, Plate XL VI, is a photograph of the curves
stacked against the power-plant wall.
4^0
CURVE RESISTANCE IN WATER PIPE
TABLE 1. — Dimensions of Curves.
[Papers.
01
0)
4)
a
am
a S
0)
1
0)
a «
o a_^
Material.
a
t; 1. 0)
3
■•^
CQ
fl-S a
■a
OS'S
'^
oq
+
tf
M
-r;
Wrought iron.
10.00
30
10.54
10.52
21.06
16.77
7.50
15
8.04
8.02
16.06
12.84
11 ti
5.00
10
5.59
5.57
11.16
9.01
" "
4.00
8
4.54
4.. 52
9.06
7.34
" "
3.00
6
3.60
3.58
7.18
5.89
2..'^0
5
3.05
3.10
6.15
5.08
Cast iron.
2.00
4
2.25
2.25
4.50
3.64
" "
l.CO
3
1.75
1.75
3.50
2.86
1.08
2.16
1.50
1.50
3.00
2.54
I. n
0.95
1.90
1.08
1.08
2.16
1.75
" "
0.88
1.76
2.00
2.00
4.00
3.62
0.67
1.34
0.67
0.67
1.34
1.05
cs S ce
6.09in
6.18
6.16
6.11
6.11
6.09
5.91
5.95
5.91
5.91
5.95
5.93
The dimensions of the cvirves are given in Table 1, in which ref-
erence is made to the dimensions indicated in Fig. 2. The dimensions
in Table 1 are for the curves as placed in the pipe line, the vvrought-
iron bends having screw flanges attached. The distances from the
faces of the flanges to the ends of the wrought-iron curves were as
follows: Curves Nos. 1, 2, 3, and 4, up-stream end, i in., down-stream
end, ^1 in.; Curve No, 5, up-stream end, i in., down-stream end, | in;
Curve No. 6, up-stream end, 1 in., down-stream end, f in. The inside
diameters of Curve No. 6 were measured also at points 22^°, 45° and
G7^° from the up-stream end. At these points, i-in. taps for the in-
sertion of a Pitot tube had been made on both the vertical and hori-
zontal diameters. The measurements were as follows: at 22i°, 5.92
and 6.09 in.; at 45°, 6.08 and 6.08 in.; at 67^, 5.95 and 6.15 in.
Papers.] CURVE KEiSlSTANCE IN WATER PIPE 421
Curves Nos. 9 and 11 were made in error, the foundry making
curves of quite short radius, with straight portions at each end, so
that the dimensions from the center to the face were 18 and 24 in.,
respectively, where the writer's order called for curves with the same
radii as the center-to-face dimensions. Curves Nos. 7 and 8 were made
later, to correct this error.
The experimental pipe line was arranged with the idea of keeping
all conditions the same except for the introduction of the several
curves. Consequently, the flange joints in the portion down stream
from the curves were not disturbed throughout the experiments. The
entire length of 85 ft. of 6-in. wrought-iron pipe, together with the
nozzle, was shifted bodily when a new curve was placed in the line.
This was rather vigorous exercise for two men, but it was accomplished
by a judicious tilting of the wooden horses supporting that part of
the pipe line. The portion up stream from the curves was left un-
changed during the experiments.
The same up-stream piezometer was used for the curve experi-
ments as for the first straight-pipe experiments. The down-stream
piezometer was a new one, of the same type, placed 1.05 ft. up stream
from the down-stream end of Pipe No. 5 which adjoined the nozzle.
A similar intermediate piezometer was placed 2.00 ft. up stream from
the down-stream end of Pipe No. 3.
At first it was assumed that some effect of the curves might ex-
tend 100 or more diameters down stream in the straight pipe beyond.*
The losses of head in all the curve experiments were measured be-
tween -the piezometer just up stream from the curves and the piezometer
just up stream from the nozzle, distant 168 diameters down stream
from the curves. These two piezometers were connected to the two
branches of a differential U-tube mercury gauge by lines of i-in. or
A-in. three-ply rubber tubing. The nozzle piezometer was connected to
one branch of an 8-ft. mercury U-tube gauge, the other branch of
which was open to the atmosphere. These gauges were provided with
blow-off cocks for the removal of air from the gauge and connections.
In experimenting, the 6-in. valve was first opened wide to establish
a swift flow through the pipe line. The gauge hoses connected to the
piezometers were allowed to run for a while before connecting them
to the gauges, being pinched near the gauge end while connecting up.
* Transactions. Am. Soc. C. E., Vol. XL VII, 1902, p. 302.
423 CURVE RESISTANCE IN WATER PIPE [Papers
Finally, the pet-cocks were opened, and all traces of air were blown
oft". Then the gauge readings were recorded and checked. The 6-in.
valve was then closed a little, and the readings were taken again as
soon as the flow had become settled. In this way ten or twelve runs
were made, the last being generally a repetition of the first run with
the valve wide open. If there was time, a new curve was then placed
in the line. Otherwise, the change was deferred until another dny,
in which case one or more check runs were made at the high velocities
before removing the curve and substituting another. For each set-up,
the level of the center of the nozzle with reference to the nozzle
mercury gauge scale was determined. The alignment of the down-
stream tangent was corrected after each change of curves.
When the work on the twelve curves had been finished, Curve No.
G was replaced in the line to find whether or not any appreciable
change in the condition of the pipes had occurred during the experi-
ments. Then a number of Pitol-tube studies were made to determine
the conditions of flow at the piezometers and in the curve. Later, a
6-in. screw elbow, of the ordinary steam-fitting type, was placed in
the line, and a series of measurements made on it as for the other
curves. Finally, the loss of head was measured in the portion (46.10
ft. long) of the experimental section farthest down stream, Pitot tube
traverses having shown normal flow in the pipe 38 ft., or 76 diameters,
down stream from the curves. Hence, this portion represented straight
pipe unaffected by curvature effects.
The results of these loss-of-head measurements are given in Table
2. For simplicity, there is given only the mean velocity in the pipe
line as deduced from the nozzle mercury pressure gauge indications.
The differential mercury gauge differences are taken directly from the
checked subtractions in the field notebook. These differences, multi-
plied by 12.57, would give the loss of head, in feet of water, the
specific gravity of mercury being taken as 13.57.
To illustrate the calculations involved in obtaining the velocity
ill the pipe line from the observations in the mercury pressure gauge
the following is a sample:
In Experiment No. 1, Curve No. 1, October 10th, 1907, the gauge
readings were: left 0.270, right 7.900. The difference is 7.630 ft.
The center of the nozzle-tip level was at 1.81 on the gauge scale.
ITcnce the top of the left mercury column was 1.54 ft. below the
ccnlcr of the nozzle tip. The pressure head at the base of the nozzle,
PLATE XLVII.
PAPERS. AM. SOC. C. E.
MAY, 1903.
8CH0DER ON
CURVE RESISTANCE IN WATER PIPES.
6-INCH PIPE, 90°CURVE EXPERIMENTS.
Logarithmic Plotting of Observed Difterentlnl Mercury Gauge Differences, with
Mean Velocities In the Pipe lino, showing the Losses of Head in the E-xpcrimental
Length as varied only by the introduction of the several Curves. Also the corre-
sponding Plotting for Straight Pipe without Curvature Effects. _
Differential Mercury Gauge Difference, Feet
Velocity, in Feet per Second
I
♦
Foldout
Here
♦ ♦
♦
II
tC.li) Ft. o£
;raight Pipe
out curvature
etfects.
Papers.] CURVE RESISTANCE IN WATER PIPE 4'23
therefore, was 7.G30 X 13.57 — 1.54 = 102.1 ft. The diameter of the
nozzle tip was 2.738 in., and the diameter of the nozzle base was 6.128
in., the ratio of areas being 1 : 5. Theoretically, the nozzle-tip velocity
is C \j /I \2 ■/ 2 gk= C'X S.l'.» s/'h, where //, is the pressure lu^ad
at the nozzle l)ase. As stated above, tlie coettieient C, for this nozzle
had been found io be 0.988 by experiment. The mean diameter of the
pipe line is 6.084 in. Therefore the mean velocity in the experimental
portion of the pipe line was: V = 0.988 X 8.19 X (g4li) '^ ^^^ "
1.639 v'/t. This gives, for this experiment, V = 1.639 X \/l02.T =
16.56 ft. per sec.
The results given in Table 2 were plotted logarithmically on 10-in.
base paper. Plate XLVII shows these plottings assembled.
Now, in order to study the effects of the curves, it is necessary to
select a uniform basis of comparison. Thus the experiments were
made by introducing the various curves between two fixed lengths of
pipe. For this case, the observed losses of head may be compared with
each other at once by using Table 2 or Plate XLVII ; but such a basis
takes no account of the comparative lengths of the several pipe lines,
nor does it consider whether or not the same two points are joined by
the combinations of straight pipes and curves.
The writer has chosen two bases of comparison. In one, all cases
are reduced to equal lengths on the center lines of straight pipes and
curves. In the other, all cases are reduced to what they would be if
two fixed points had been connected by two straight pipe lines with
the various 90° curves between them.
For both these cases it is necessary to know the loss of head in the
straight pipe when it is unaffected by curvature. Two series of ex-
periments already described give this information.
Turning to Plate XLVII, it is seen that the results of the first
straight-pipe experiments do not agree with the later ones. Each
series gives a good straight line, but the two lines have different slopes
and represent different laws of flow. The equations of these lines, re-
duced so as to represent loss of head in feet of water per foot length
of pipe, are
For the llrst series, ff = 0.000 OC!) V^-^'
For the later series, 7/ = 0.000 5'.>S F'--'*
426
CURVE RESISTANCE IN WATER PIPE
[ Pa pcis.
TABLE 2 (Coniinued).
Date,
1907.
Oct. 19.
Oc-(. 21.
Oct. 24.
n^.
g btxu
53 o3 a
S >;«
jj o aj
> In bi
life
Curve No. 11.
1.050
0.S126
().f)07
0.320
0.275
0.241
0.202
0.120
0.0.56
0.032
1.046
1.052
0.715
16.59
15.53
12.40
8.99
8.41
7.75
7.07
5.41
3.78
2.87
16.56
16.58
13.60
Curve No. 12.
1.046
1.009
0.818
0.558
0.320
0.168
0.072
0.087
0.612
1.040
16.62
16.31
14.65
12.01
8.92
6.43
4.21
2.74
12.61
Ki.Ol
Screw Elbow.
Sag
Date,
1907.
0
a
OJ
«
x>
i
<o
a.
!z;
Ed
vg I
o a;
w
■■9
01 r-
6JD-.S
47^
Straight Pipe Experiments.
\ Temperature of water:
First Series: -. 68° at beginning,
I 70" at end.
43
43
Nov. 12..
1
1.090
16.55
37
2
1.036
16.15
Nov. 18..
3
1.098
16.55
33
4
1.053
16.21
0
0.912
15.02
6
0.682
12.94
7
0.515
11.20
8
0.331
8.93
9
0.174
6.40
10
0.071
4.04
11
1.088
16.55
Sept. 4..
1
1.901
0.0701
6.03
2
1.687
0.0622
5.67
3
1.449
0.0535
5.22
4
1.241
0.0458
4.80
5
1.000
0.0369
4.29
fi
0.881
0.0307
3.88
7
0.704
0.0260
3.55
8
0.473
0.0175
2.87
9
0.307
0.0114
2.27
10
0.160
0.0059
1.61
Sci-
,„,1 Series*' * 'r*'"'P*"''*^'^i"'2 *?''
.iKiheiies . 1 water, ;«° fain-.
&"™='
Nov 18..
1
13.70 0.506
16.56
2
13.19 0.487
16.23
3
10.24 0.378
14.29
4
6.83 0.2525
11.56
5
4.40 0.1625
9.26
6
2.45 0.0905
6.93
* The
velocities for the second series are
compute
d for the mean diameter of the ex-
peruneu
6.075 in.
tal section (46.10 ft. long) which was
Papers.] CURVE RESISTANCE IN WATER PIPE 427
To show more clearly the magnitude of this difference, the follow
ing caleiilated values are given:
Loss of head, in feet of water per foot of length :
T'= 3 ft.
F = 5 f t.
F = 10 ft.
I'= 10 ft,
per see.
per sec.
per sec.
per see.
First series
o.oons
0.0135
0.049
0.119
Later series
0.0050
0.0135
0.052
0.129
Thus, at the outset, comes the question which must arise in all
experiments of this kind: What was the law of flow of the identical
straight pipe used with the curves when unaffected by curvature, but
otherwise in the same condition ? On this depends the calculation of
the excess loss of head caused by the curves.
Thore are a number of possible causes for the difference shown
above :
1. — The pipe may have become rougher by rusting in the interval
between the two series of experiments;
2. — Pipes Nos. 4 and 5 together may have had different hydraulic
properties from Pipes Nos. 2, 3, 4, and 5 together;
3. — The different temperatures of the water may have caused a
difference in loss of head.
It was intended originally to bring the straight pipes back to the
hydraulic laboratory and again test them as at first for loss of head
after the curve experiments had been finished, but the lateness of the
season prevented this.
Later in this paper the above possible causes of differences will be
discussed more fully. In order to remove any qtiestion as to mistaken
judgment, the results are worked up in both ways.
The individual observations, directly, are not used in the final
comparisons. From the mean lines drawn on the logarithmic diagram,
where all observed values for each curve have been plotted, the gauge-
difference values for velocities of 3, 5, 10, and 16 ft. per sec. have
been picked off. These values are given in Table 3.
All the cases have been reduced to the length conditions existing in
the set-up for Curve No. 1. For the first comparison, the observed dif-
ferential mercury-gauge differences for the other curves have been
increased by an amount corresponding to the additional length of
straight pipe necessary to give the same length on the center line as
«"? we-:
%t ,i ,
Axil •.»l>'.J}(!h'.Hj>i«»J
f*^
•» n -die -jmn
■> MS
•t.Ki
•I *1
'I A I; 1,1
i^X* TO RFDfCT. Alt.
I
Nt.
of ciirv*'.
1. r
:j
7 75
4
tt.42
lO.KT
11. «8
~
13.12
For equal To connec-t
9o <rf e«rre. Imsttsoo two fixed
, crater Bnes.
8
9
10
11
12
Screw elbow.
14.28 •
13.01 "
1.3.14 -
15,71 '•
points.
17.56 ft.
18.06 •'
1H.90 '■
17.06 "
19.72 •
20. n« ••
.1
gives the len^ of straight pipe to be added for eacli
e two cases to rluce all to the conditions of Curve No. 1.
<>i liead per footength of straight pipe is given in Table b.
ables r> and 4, he individual corrections are calculated,
ults are given in Tae C.
m^
Papers.]
CURVE RESISTANCE IN \ ATKR VIPE
TABLE f
4:2\)
Velocity,
in feel
per second.
From thk Firsst Experiments : From the Second Experiments :
Mercury difFerential- - ^ . Mercury differential-
gauge differences wrjop gauge differences,
in feet. water. j^^ ^^^
Feet of
water.
3
5
10
16
0.000M2 0.00518 0.000399
0.001071 : 0.01346 0.001075
0.00;»03 0.0491 0.00412
0.00943 0.1185 0.01026
0.00502
0.0135
0.0518
0.129
TABLE U. — CoRRKCTioNs TO BE Added '1 Observed Differential Mer-
cury-Gauge DiFFERE.NCES TO ReDIT". AlL CaSES FOR COMPARISON
WITH Conditions of Curve No. 1, : Feet.
For Equal Lenuths on Center Lines:
1.)
Connect Two Fixed Points:
No of
Velocity, in feet per second.
No,f
car\
Velocity, in feet per second.
curve.
3
6
10 16
3
5
10
16
On Basis of First StraightPipe Experiments.
2
0.0016
0.004-2
0.015
0.087
,-,
0.0021
0.0054
0.020
0.047
8
0.0082
0.0OS3
O.OMO
0.078
b
0.0041
0.0106
0.039
0.093
4
0.0089
0.0101
0.037
0.089
4
0.0049
0.0129
0.017
0.113
5
0.0M5
0.0348
0.0117
0.042
0.103
5
0.0057
0.0149
0.054
0.131
6
0.0125
0.046
0.110
f,
0.0061
0.0160
0.058
0.141
7
0.0054
0.0141
0.051
0.124
O.OOIW
0.0177
0.065
0.156
8
0.0057
0.0149
0.054
0.131
0.0072
0.01«8
0.069
0.166
9
0.0059
0.01.52
0.056
0.134
0.0074
0.0194
0.070
0.170
10
0.0068
0.0161
0.059
0.142
1(
0.0078
0.0202
0.074
0.178
11
0.0054
0.0141
0.051
0.1-24
.11
0.0070
0.0183
0.067
0.161
12
0.0065
0.0168
0.061
0.148
12
0.0081
0.0211
0.t77
0.186
Serf 1
elbc f
0.0085
0.0220
0.080
0.194
On Basis of Second Straigf-Pipe Experiments.
2
0.0010
0.0042
0.016
0.040
.'
0.0020
0.00.54
0.021
0.051
3
0.0031
0.0083
0.082
0.080
i.
0.0040
0.0106
0.041
0.102
4
0.0038
0.0102
0.038
0.097
0
0.0048
0.0129
0.049
0.123
5
0.0043
0.0117
0.045
0.112
I
0.0055
0.0149
0.0.57
0.142
6
0.0047
0.0126
0.048
0.120
f
0.00.59
0.0160
0.061
0.153
7
0.00.52
0.0141
0.054
0.135
t^
0.0066
0.0178
0.068
0.170
8
0.0055
0.0150
0.0.57
0.143
i
0.0070
0.01H9
0.072
0.180
e
0 0057
0.0153
0.(i,'i9
0.146
f
0.0072
0.0194
0.074
0.185
10
0.0060
0.0101
0.002
0.154
U
0.0075
0.0203
0.078
0.194
11
0.0052
0.0141
0.054
0.1.35
11
0.0068
0.0183
0.070
0.175
12
0.0063
0.0169
0.065
0.161
l;
0.0079
0.0212
0.081
0.202
Serf (
elbef
0.0082
0.0221
0.085
0.211
428
CURVE RESISTANCE IN WATER PIPE
[Papers.
existed between the two piezometers when Curve No. 1 was in the pipe
line. For the second comparison, the added quantity corresponds to
the extra length of pipe required to make tlie sum of the tangent
distances from the point of intersection equal to that for Curve No. 1.
These two cases may be called, for brevity, respectively, the equal-
lengths and the two-fixed-points cases.
TABLE 3. — Differential Mercury-Gauge Differences from the
Mean Lines Drawn for the Plotted Points for All the Ob-
servations, IN Feet.
No. of curve.
Velocity, in Feet per Second :
3
5
10
16
1
0.0444
0.1180
0.443
1.090
o
0.04U8
0,1083
0.410
l.OIl
3
0.0400
0.1062
0.402
0.991
4
0.0400
0.1062
0.402
0.991
5
0.0395
0.1046
0.396
0.978
6
0.0376
0.1008
0.386
0.960
7
0.0381
0.1013
0.385
0.950
8
0.0375
0.1002
0.382
0.942
9
0.0375
0.1002
0..382
0.942
10
0.0375
0.1002
0.382
0.942
11
0.0382
0.1030
0.394
0.981
12
0.0387
0.1031
0.392
0.968
Screw elbow.
0.0403
0.1077
0.413
1.030
TABLE 4. — Lengths of Straight Pipe to be Added to Reditce All
Cases to Conditions of Curve No. 1.
No. of curve.
For equal
lengths on
center lines.
3.92 ft.
7.75 "
9.42 '■
10.87 "
11.68 •'
13.12 "
To connect
two fixed
points.
No. of curve.
For equal
lengths on
center lines.
To connect
two fixed
points.
2
3
4
5
6
7
5.00 ft.
9.90 •'
12.00 "
13.88 "
14.91 "
16.56 "
8
9
10
11
12
Screw elbow.
13.90 ft.
14.22 '•
15.01 "
13.14 "
15.71 "
17.56 ft.
18.06 •'
18.90 "
17.06 "
19.72 '•
20.56 "
Table 4 gives the length of straight pipe to be added for eacli
curve for the two cases to reduce all to the conditions of Curve No. 1.
The loss of head per foot length of straight pipe is given in Table r>.
TTsing Tables r> and 4, the individual corrections are calculated.
The results are given in Table C.
Papers.]
CURVE RESISTANCE IN WATER PIPE
TABLE 5.
40:»
Velocity,
in feel
per second.
From the First Experiments :
From the Second Experiments :
Mercury differential-
gauge' difference ,
in feet.
Feet of
water.
Mercury differential-
gauge differences,
in feet.
Feet of
water.
3
5
10
16
0.000412
0.001071
0.003903
0.00943
0.00518
0.01346
0.0491
0.1185
0.000399
0.001075
0.00412
0.01026
0.00502
0.0135
0.0518
0.129
TABLE G. — CoRRFX'TiONs to be Added to Observed Differential Mer-
cuRv-G.\uGE Differences to Reduce All Cases for Comparison
WITH Conditions of Curve No. 1, in Feet.
For Equal Lengths on Center Lines:
To Connect Two Fixed Points:
No of
Velocity, in feet per second.
No. of
curve.
Velocity, in feet per second.
curve.
3
5
10 16
3
5
10
16
On Basis of Eirst Straight-Pipe Experiments.
2
0.0016
0.0043
0.015
0.037
2
0.0021
0.0054
0.030
0.047
3
0.0033
0.0083
O.OriO
0.073
3
0.0041
0.0106
0.039
0.093
4
0.0039
0.0101
0.037
0.089
4
0.0049
0.0129
0.017
0.113
5
0-0045
0.0117
0.043
0.103
5
0.00.57
0.0149
0.054
0.131
6
0.0948
0.0125
0.046
0.110
6
0.0061
0.0160
0.058
0.141
7
0.0054
0.0141
0.051
0.134
7
0.0088
0.0177
0.065
0.156
8
0.0057
0.0149
0.054
0.131
8
0.0072
0.0188
0.069
0.166
9
0.0059
0.0152
0.056
0.134
9
0.0074
0.0194
0.070
0.170
10
0.0062
0.0161
0.059
0.143
10
0.0078
0.0202
0.074
0.178
11
0.0054
0.0141
0.051
0.124
11
0.0070
0.0183
0.067
0.161
12
0.0065
0.0168
0.061
0.148
12
0.0081
0.0211
0.C77
0.186
Screw 1
elbow f
0.0085
0.0220
0.080
0.191
On Basis of Second Straight-Pipe Experiments.
2
0.0016
0.004<J
0.016
0.040
2
0.0020
0.0054
0.021
0.051
3
0.0031
0.0083
0.032
0.080
3
0.0040
0.0106
0.041
0.102
4
0.0038
0.0102
0.038
0.097
4
0.0048
0.0129
0.049
0.123
5
0.0043
0.0117
0.045
0.112
5
0.0055
0.0149
0,057
0.142
6
0.0047
0.0136
0.048
0.120
6
0.0059
0.0160
0.061
0.153
7
0.0052
0.0141
0.054
0.135
7
0.0066
0.0178
0.068
0.170
8
0.0055
0.0150
0.057
0.148
8
0.0070
0.0189
0.072
0.180
9
0 0057
0.0153
0.(1.59
0.146
9
0.0072
0.0194
0.074
0.185
10
0.0060
0.0161
0.062
0.154
10
0.0075
0.0203
0.078
0.194
11
0.0052
0.0141
0.054
0.135
11
0.0068
0.0183
0.070
0.175
12
0.0063
0.0169
0.065
0.161
12
0.0079
0.0212
0.081
0.202
Screw (
elbow f
0.0082
0.0221
0.085
0.211
432
CURVE RESISTANCE IN WATER PIPE
[Papers.
TABLE 9. — Lengths of Straight Pipe, in Feet^ to give Loss of Head
EQUAL to the ExCESS LoSS DuE TO THE CuRVES. On THE BaSIS OF
Second Straight-Pipe Experiments.
For Rqual Lengths on Center Lines:
To Connect Two Fixed
Points:
Veloci
ty, in feK
per second.
Velocity, in feet
per second.
No. of
No. of
curve.
curve.
3
5
10
4.4
16
3
5
10
16
1
8.4
6.7
3.2
1
4.0
2.4
0.2
—1.1
2
3.2
1.6
0.2
-0.6
2
o.O
—1.6
—2.7
—3.8
3
5.0
3.5
2.1
1.4
3
3.0
1.3
0.2
-0.8
4
6.8
5.3
3 9
3.0
4
5.0
3.4
2.1
1.2
.5
6.8
5.1
3.9
3.2
5
5.6
3.8
2.7
1.9
6
3.0
2.5
2.1
2.3
6
1.8
1.3
1.2
1.2
7
5.6
4.3
3.5
2.7
7
4.8
3.4
2.7
1.9
8
4.8
4.1
3.5
2.7
8
4.2
3.4
2.9
2.0
9
5.2
4.4
3.9
3.0
9
4.8
3.9
3.5
2.6
1(1
6.0
5.1
4.6
3.8
10
5.6
4.7
4.4
3.4
11
5.8
5.8
5.6
5.7
11
5.6
5.5
5.4
5.3
13
9.8
8.6
7.7
7.0
12
9.6
8.3
7.5
6.7
Screw (
elbow. )
14.3
13.4
13.5
13.6
TABLE 10. — Excess Losses of Head Due to Curves, Expressed in
Terms of Velocity Heads. On Basis of Second Straight-Pipe
Experiments.
For Equal Lengths on Center Lines:
To Connect Two Fixed Points:
Velocity, in feet per second.
Velocity, in feet per second.
No. of
3
5
10
16
No. of
curve.
t-
S
TO
(2
curve.
5^
*%
in
a
o
,_
TO
II
II
II
II
3
5
10
16
fc.^
tLJ^
tL <^
^ ^g"
0.14
1
0.30
0.23
0.15
0.10
1
0.08
0.01
-0.04
2
0.11
0.05
0.01
-0.02
2
0.00
—0.05
—0.09
—0.13
3
0.18
0.12
0.07
0.05
3
0.11
0.05
O.dl
-0.03
4
0.24
0.18
0.13
0.10
4
0.18
0.12
0.07
0.04
5
0.24
0.18
0.13
0.10
o
0.20
0.13
0.09
0.06
6
n.ii
0.08
0.07
0.07
6
0.06
0.05
0.04
0.04
7
0.20
0.15
0.12
0.09
1
0.17
0.13
0.09
0.06
8
0.17
0.14
0.12
0.09
8
0.15
0.12
0.10
0.07
9
0.19
0.15
0.13
0.10
9
0.1?
0.14
0.12
0.08
10
0.21
0.18
0.15
0.12
10
0.30
0.16
0.15
0.11
11
0.21
0.20
0.19
0.19
11
0.30
0.19
C.18
0.17
12
0.35
0.30
0.26
0.33
12
0.34
0.39
0.35
0.22
Screw elbow.
0.52
0.47
0.45
0.44
Papers.]
CURVE RESISTANCE IN WATER PIPE
433
tendency represents the trntli, tlien a remarkable dilemma is presented.
As the curvatvire of a pipe becomes less and less the external condi-
tions approach nearer to those of straight pipe. The natural in-
ference is that the loss of head also approaches straight-pipe values,
unless, indeed, it be argued that the slightest deflection from straight
pipe immediately causes a considerable excess loss of head.* For-
5 G
Radius of Ciirve.in Feet
Figs. 3 and 4.
tunately, there exist experimental data which will assist in the con-
sideration of these points. These will be given presently.
Fig. G shows the same tendency as Fig. 5, although the decrease in
loss of head with increasing radius of curvature is less decided on the
basis of the first straight-pipe experiments.
♦Detroit Curve Experiments, Transactions, Am. Soc. C. E., Vol. XLVII, 1902. Cod-
elusion J, page 191, and pages 186-187.
434
CURVE RESISTANCE IN WATER PIPE
[Papers.
As to the diflFerence found between tlie results of the two straight-
pipe series, the following may be stated. Conditions of temperature
were favorable for some rusting during September, after the first
straight-pipe series and before the fii*st curve experiments were made.
0.9
0.8
^
K
"o.r
y
'C
I
0.0
p
3
0.5
to
c
■p
5)
0.4
o
C3
0.3
o
~
■;;
0.2
'~'
o
^
a
0.1
7
Q)
s
J3
-0.1
3h
O
-
-3
-0.2
^
^
i
-0.3
1.
o
_o
-0.4
01
C
-0.5
►^
1:14
o
bO
V 1 >^
\
90°CURVE EXPERIMENTS,
6.INCH PIPE
\
T
Y 1
f.,
\
._r^
1
„ "t-|T,?*;^'<
.5j.Mi;-M*i^
.^.^
fe^
r^
w
(
i — -
ss^
_
^■^
\
^'^^
N
\
"^
r''
y
N.
\,
/■
y
v
\
y
^
\
/"
4 5 6
Radius of Curve, in feet
Radius of Curve.in feet
Figs. 5 a.nd fi.
During the curve experiments, the data show no indication of increas-
ing roughness, or of any effect of changes in temperatiire of the
water.* All the straight pipes had been used in a steam-heating main
*This is remarliable. It has been observed, for smooth brass pipes of all sizes between
,'n in. and 5 in. in diameter, that the loss of head is increased about 4"„ for a decrease of
temperature of the water of 10" fahr. Rougher pipes, such as Ka'vaiiis'ed iron and wrought
iron, show no effect due to temperature changes.
Papers. ]
CURVE KKSTSTANCE IN WATER RIPE
435
for some years, and all seemed to have a uniform internal appearance.
The first series had no velocities greater than 6 ft. per sec, while the
second series had velocities as hi^h as in the curve experiments. A
~ s
bo '5 a
o i: '5
s
1
90°CURVE EXPERIMENTS,
/
i
fc
6-INCH PIPE
1
s
^
^*
}
1
/
'"""'
■-"•^.
(^
,,
y
I
k
,.'^
,
1
1
1
V —
-4. •-^'
./
/
f
4
e-X4\
11
^
.%
'T^^
~^*
^i^^
"•'•
■~-.«
^
/
/•■
A
r-^
il
^-^
"■-^
"^o"
/
./
-^
-^
?
^^
-J
^
•
'
,/
y
/
+-^
^-*,
^^
T
/V
"^
^.
^-
^y
y^^
-Y
4 5 6
Radius of t'urvo, in Foot
Fig, 7.
10
4 5 6
lladiiis of <-'urve,in Feet
Fig. 8
separate measurement of the loss of head in Pipes l^os. 2 and 3 when
Tuiinfluenced hy curvature was not made, and it is impossible to de-
cide as to their hydra idic properties as compared with Pipes Nos. \
and 5.
436
CURVE RESISTANCE IN AVATER PIPE
[Papers.
It is thus clear tliat, without additional evidence, it is not possible
to reject one of the straight-pipe series and accept the other, or to feel
safe in using average values.
In relation to this matter, the writer desires to present the data
from measurements on an 8-in. cast-iron water main. This nuiin sup-
plies raw water to the Cornell University Filtration Plant.* It had
Ixeu laid and in use for three years before the experiments in the fall
(if 1!K)0. Before laying, the inside diameter of each length had been
calipered. At the time of laying, each pipe length was set accurately
to line and grade with a transit. After laying, and before covering
CORNELL UNIVERSITY
8-INCH CAST-IRON RAW WATER
PIPE LINE This Inlcrincilalt tangent contains
,.,,., , ..^^^ -^ , . . , Change of grade made
lift.plpe lengths. ^^^ Change of grade made b; . ,h i, d
Change of graJe made b;
five equal deflect;
Change of grade made bj conBecutire pipe joints
O.^iC'lU'iii
PROFILE
LengthB betnoeti plczuiiiolers on
centur line. Feet
B-f HO.SU I -J 106.06
81.03
82.82
1IJ'J.07
L-M
i.28
Mean diameter^ IncbeB,
£ - F 7.999 / -J 8.000
F-a 8.O30 J-K 8.022,
a-U 8.008 K-L not Measured
900-
8'JO
880
DiameterB, Vertical, at . -g^Q -
piezometer tape. Inches
f 7M / 7.98 M 7.S3-8(iO-
f! 7.98 J 7.97
a 8.0fi K 8.05 850-
fl 8.02 X 7.94
810
830
^.OOii
L M
a II
.l.tl.ctlo
tioual |.ol
FiQ. 9.
the pipe, the piezometer holes were drilled and tajiped, and the diam-
eters measvired at these points; the ;i-in. brass pi<'/.onieter cocks were
inserted so as not to project inside, and the lengths between the
piezometers were measure<l and checked in the ditcli.
The plan antl profile of the pipe line are shown by Fig. 9. There
are eight experimental sections, four of which contain deflections, and
four of which are straight, preceded by considerable lengths of straight
pipe.
The piezometer taps were placed on top of the pipe and 1 ft. up
stream from the joints, except that those before deflections were placed
2 ft. up stream from the joint where the first deflection occurred.
The flow in the pipe line was measured at the filter plant by a
*Designerl by G. S. Williams, M. Am. Soc. C. E. See The EiKjinecn'iin Record, April Otli, ItVM.
Papers.]
CUHVK KKSISTANCK IN WATKR I'll'K
437
10
"
/
8
/
¥
'i
6
5
4
3.5
3
•^.5
ri
oi
•
ect
on
E-F
J
o
+
I-J
K-
L
f
t
0
f
r
T
1.5
1
^
-1
i
c
>'
f
;
/
/
^
0.9
0.8
0.7
O.C
0.5
0.4
r
/
/
8-INCH CAST-IRON PIPE
7
to
3ARITHWIIC PLOTTING
FOR
^
'
s
Sec
TRAIGHT SECTIONS
; Fig.9 for Dimensions
/^
f
0.3
(
/
/
/
0.5 0.6 0.7 0.8 0.9 1 1.5 2 2.5
Velocity, in Feet per Second
Fig. 10,
438 CURVE RESISTANCE IN WATEK I'll'i: [I'apcis.
Venturi meter which had been accurately calibrated in place by
volumetric measurements. A differential water gauge was used with
the meter. The losses of head were measured with a portable differ-
ential water gauge mounted on a tripod. The gauge was set up on
the ground midway between two piezometer wells, and pressure con-
nections were made with small three-ply rul)ber hose after thoroughly
blowing off to remove all air.
The flow was controlled by a" valve at the Alter plant. It was i)OS-
sible to shut this valve down entirely, and thus get no-flow conditions
and a check on the gauge readings. The electric motor-driven two-
stage centrifugal pumps at the lower end of the pipe line allowed this
procedure without any trouble.
After changing the valve setting and allowing the flow to become
steady, simultaneous readings were taken on the meter and the loss-
of-head gauges. The results are shown graphically in Figs. 10 and 11.
For the straight sections the observed losses of head have been reduced
uniformly to loss per 1 000 ft. It will be seen on Fig. 10 that the
straight sections differ among themselves. Thus Section E-F has less
and Section K-L has greater loss of head than the average of the four
sections; in fact, Section K-L has about 15% greater loss of head
than Section E-F. The equation of the mean line for the four sec-
tions of straight pipe is
H =:0.58G T^^-^^
where H is the loss of head, in feet per 1 000 ft., and V is the velocity,
in feet per second. (The corresponding values of 0, in T^ ^ C sj R 8,
are: at 1 ft. per sec, 101; at 4 ft. per sec, 107.)
Fig. 11 shows the difference between this average law of flow for
the straight portions and the hydraulics of the sections containing de-
flections. It is remarkable that Section F-G with a single 3.8° de-
flection. Section H-I with a curve composed of five 3.17° deflections,
and Section J-K with a reverse curve composed of one curve with
five 2.18° deflections and another with four 2.81° deflections, all show,
on the whole, less loss of head than the average of equal lengths of
straight pipe. Section L-M, with a short-radius bend giving a deflec-
tion of 12° 56', is the only one showing a greater loss of head.
The writer does not argue from this that such easy curves or de-
flections are more favorable fm' (lie flow of water than straight pipe.
Papers.]
ciMai; i;i:s I STANCE ix watku pipe
439
1
0.9
0.8
0.7
00
/
f
1 1 1 1 1 1 M M 1 ! i
•/
1
/
8-lNCH CAST-IRON PIPE
LOGARITHMIC PLOTTING
FOR SECTIONS
CONTAINING DEFLECTIONS
p i
f f
f
>/
J.
/
/
11
0.5
0.45
0.4
0.35
■» 0.3
a)
"cS
F
J/
4)
/
n
tA>
1
/
(
/
/
/%
8)
/
(
1
t
c
/
r
/
/
o/j
> 0.S5
o
fa
-o 0.15
<a
K
0
en
»
3 0.1
% 0.09
1 O.OS
1 0.07
0.06
0.05
0.04
0.03
on-"
i
1
0
y
/
f
•
c
V
I
/
f
f
j
/
/
■
<
/
V
)
/
/
/
/
/
/
i
(^
/
/
)
i
•
/
/
3
f\
\f
J
/
/
/
/
/
/(t
^
/
/
/
/
'1
/
/
h
V
The lines are not drawn to fit the plotted points,
but represent the eonditions in the straight
portions of the pipe line for lengths equal to
the lengths of the sections with detlections.
Hence this plotting shows graphically the
excess or deficiency in loss of head due to the
deflections.
See Fig.9 for Plan and Profile of Pipe Line
with dimensions.
/
/
O
7
"//
k)
^
7
0.5 0.6 O.T 0.8 0.9 1
1.5 3 3.5 3
Velocity, in Feet per Second
Fig. 11.
440 CURVE RESISTANCE IN WATER PIPE [Papers.
but he does see the indication that any difference is very small and
may be less than the difference between two straight sections in the
same pipe line, as occurs in the case above recorded.
The 6-in. wrought-iron pipe experiments also give some informa-
tion on the question of the effect of slight deflections in otherwise
straight pipe. The first series, of October 10th, 1907, was made with
a decidedly zigzag appearance of the down-stream tangent, that is,
the joints were not in a straight line, although the individual pipe
k'ngths themselves were straight. On October 12th the series was re-
peated, but with the down-stream tangent carefully aligned. No dif-
ference in results is noticeable.
Viewed in the light of the foregoing, it is easy to decide that the
first 6-in. straight-pipe experiments do not apply to the later curve
experiments because the deduced excess loss of head docs not continue
to approach zero .for the long easy curves. In this respect, the differ-
ence between Figs. 3 and 4 is noteworthy.
Now, all of this contradicts the findings of Messrs. Williams, Hub-
bell, and Fenkell in the Detroit Experiments. The writer cannot
imagine that radically different' laws apply to the cases investigated
by him and by these experimenters.
One difference in conditions is to be noted, however. The long-
radius curves in the 30-in. Detroit main were made up of several
pieces, while the writer's 6-in. curves were all one-piece bends. As to
the probable small effect of the joints, the writer's 8-in. pipe experi-
ments, with small deflections, give some idea; but there are other pos-
sible causes for the divergence of the findings. The smallness of the
measured losses, with the comparatively low velocities available in the
Detroit 30-in. main, would tend to magnify excess losses due to other
effects than curvature. Thus, in Figs. 3 and 5 it will be seen that a
very different appeal to the eye is given by the line for a velocity of
16 ft. per sec. than by the line for a velocity of 3 or even 5 ft. per sec.
There remains, also, for the Detroit Experiments, the possibility
of relatively large errors due to several causes. These errors were
considered by Messrs. Williams, Hubbell, and Fenkell in their closing
discussion, and a table was presented* in which corrections — as large
fs 50% in one case — were made to the results given in the main part
of the paper. These corrections materially alter the appearance of
the remarkable Fig. 90 of the paper.
*Table No. 89, page 360, Transactions, Am Soc. C. E., Vol. XLVII, 1902.
Papers.] CURVE RESISTANCE IN WATER PIPE 441
If, now, ill the Detroit Experiments, to the causes for uicorrect
deductions above mentioned there be added the effect of using for com-
parison the results of experiments on short sections of straight pipe
that might have had quite different hydraulic properties from the
straight pipe in the curve section, it is easy to see that the combination
of circumstances may have led to conclusions not at all general in
their applicability, and perhaps even wrong for the case iji hand; but,
as to this matter, the writer is quite content with suggesting the
salient arguments.
After all, however, the engineer will be particularly interested in
the magnitude of the excess losses of head due to curves. Are they
seriously large in an extreme case?
Figs. 7 and 8 show that the excess loss of head for the shortest 90'^
curve is equal to the loss in 7 to 10 ft. (or 14 to 20 diameters) length of
straight pipe. When the radius is 2^ diameters the excess loss of
head is equal to the loss in 5 to 10 diameters length of straight pipe.
In this relation Fig. 12 is interesting. It is seen that, for the smooth
brass 180° curves, the excess loss of head is rather less than the loss of
head in 7 diameters length of straight pipe. The expression,
045 = n~> seems to give a fair average value for the range of these
brass-curve experiments.
Table 9 shows that the 6-in. screw elbow gives an excess loss of
head equal to the loss in about 27 diameters length of straight wrought-
iron pipe. The writer has also the record of some accurate measure-
ments on the loss due to 3-in. and 4-in. screw elbows, from which it
appears that the losses are equal, respectively, to the losses in 25 and 27
diameters length of straight wrought-iron pipe.
When, therefore, the Detroit Experiments, after thorough revision,
indicate for a long easy curve in 30-in. pipe an excess loss of head
equal to the loss in 50 diameters length of straight pipe, not only does
tlie loss seem to be too large when compared with the loss in a screw
elbow where sudden enlargement and contraction are present in addi-
tion to extremely short-turn curvature effects, but the whole trend of
the results is directly the opposite of what is shown by the writer's
experiments on 6 and 8-in. pipes.
Now, it may be that Nature changes her methods somewhere be-
tween pipes of 8 and 30 in. in diameter, as regards the effects of
443
CURVE RESISTANCE IN WATER PIPE
[Papers.
curvature. It must be so, if both the Detroit Experiments and those
of the writer have been interpreted correctly. The evidence seems
to stand as follows: In Detroit, with a small range of low velocities
(the greatest about 3 ft. per sec.) the 30-in. pipe line shows an increas-
0.07
0.06
■ — 1- ■[■ 1
1 1
I 1
H
180"CURVESilN 2.09-lNCH
BRASS PIPE LINE
^RITHMIC PLOTTING OF DATA FROM TAB
*ol,
^
Log/
E 77,
5>^
!l
Straight Pipe, in Feet of Water,
Transactions AM SOC. C. E., VOL. XLVll,
1902,PAGES 318-319.
EXPERIMENTS BY SAPH AND SCHODER
• Curve >.'o.l, niuliub=^9.58 l'ij)e Diiinieteis
o •• •• 2 '■ 7.03 •'
+ •• •■3 •• 5.77 •'
O •■ •• -1 •• 4.7fi ••
a " "5 " 4.;i3 ■•
® •■ "6 " .">.8} '•
/
1
.*!
V
®
O
^■'i
1
r
4//
)
A / /
"3
i'/
//T^
t)
of Head ove
#7^
)
Excess Loss
1 i i
+
/
/
f
/'
i, 1
7
®
<
D
/
/
/
/
u
1
/
/
/
/
/
/
/
/
/
1
■n-
®
a
0.5 0.() 0.7 0.3 O.y 1.0
Velocity, in Feet per Second
Fig. 12.
iiig loss of head with increasing radius of curvature for curves with
radii between 5 and 25 diameters. (The other pipe lines, 12 and 16-in.,
have only short-radius curves, and the results are not consistent.) The
writer's experiments on G-in. i)ipe, with velocities up to 16 ft. per sec.
Papers.] CURVE RESISTANCE IN WATER PIPE 443
show the opposite. His 8-in. pipe experiments indicate no measurable
excess loss of head for bends composed of a series of small deflections
a1 consecutive joints in ordinary cast-iron pipe, and his 6-in. pipe also
shows no appreciable excess loss for several small deflections. The
quantitative results for the long Detroit 30-in. 90° curves are far in
excess of the 180° 2-in. brass curves, the writer's 6-in. 90° curves, the
3, 4 and G-in. screw elbows, and, as above stated, are contradicted by
the no-excess results of the 8-in. long, easy curves.
If, then, for any reason, an engineer wishes to use a long, easy
curve, or a series of small deflections, in the joints between straight
pipes, the writer's experiments indicate just what most hydraulic en-
gineers have assumed, namely, that there is practically no differenco
between the loss of head due to a long, easy curve and that due to an
equal length of straight pipe.
No calculations on the basis of the loss of head per foot length of
curved portion have been made, because all the excess loss of head
probably does not occur in the curve, an unknown part of the loss
taking place in the down-stream tangent in the region where the ab-
normal flow returns to normal. Partly for this reason, also, it was
not deemed wise to attempt any correction on account of the smaller
diameter of the 6-in. cast-iron curves, or, indeed, on account of the
variation in the diametei"s of any of the curves from the mean diam-
eter of the straight pipe. Besides, we have no precise knowledge con-
cerning the effects of slight sudden enlargements or contractions, such
as are involved in these experiments.
The writer has found this an interesting study, and would gladly
have extended the experiments to other sizes of pipes, but the cost, in
time and money, is rather large, lie would suggest the desirability
of similar studies on other small sizes, and of many further experi-
ments on curves in existing large pipe lines.
The writer desires to acknowledge his indebtedness to Professor
W. B. Gregory, who worked with him throughout the 6-in. pipe ex-
periments, and in subsequent Pitot tube investigations in the course
of which it was shown tliat normal flow prevailed at all the piezometers
in the 6-in. pipe.
After preparing this paper, the writer's attention was called to a
record of experiments on 90° bends in 3 and 4-in. pipes.* These ex-
* Paper No. 3679, " Loss of Pressure in Water Flowing: through Straight and Curved
Pipes," by Arthur William Brightmore. M. Inst. C. E., Mhiiitex nf Procefdinyx, Inst. C. E.,
Vol. CLXIX. mw-ltHjT, p. 393.
444
CURVE RESISTANCE IN WATER PIPE
[Papers.
periments covered a right-angled elbow and right-angled bends having
radii equal to 2, 4, G, 8, 10, 12, and 14 diameters in ;3-in. pipe, and the
same, excepting the last two, in 4-in. pipe.
The arrangement resembled that by the writer except that the
down-stream piezometer was located rather close to the curves, being
6 ft. 8 in., or 27 diameters, distant for the 3-in. pipe, and from 5 ft.
to 6 ft. 1i in., or from 15 to 19 diameters, distant for the 4-in. pipe.
The length of straight pipe up stream from the up-stream piezometer
was 7 ft. for both the 3 and 4-in. pipes.
Fig. 13 is a reproduction of Mr. Brightmore's plotting of the re-
sults of his experiments. There is a striking similarity between the
iD OD 8D IOC
Radius of Beml, in Diameters.
Fig. 13.
shape of his curves and those by the writer in Fig. 3 (which corre-
sponds to Fig. 13). The hump in the curves between G and 8 diam-
eters appears in both Figs. 3 and 13. The quantitative results are not
readily compared. For Mr. Brightmore's 4-in. pipe the straight pipe
(rusted cast iron) liad a coefficient of 47.5 in the formula, V = C ^^ R is.
For the 3-in. pipe (galvanized) the coefficient was 65 to 70 for V,
ranging from 3 to 11 ft. per sec. In the writer's experiments, the co-
efficient for the G-in. wrought-iron pipe was 119 to 125 for V ranging
from 3 to IG ft. per sec. Mr. Brightmore purposely allowed the pipes
and curves to become rusted, but, he states, not tuberculated. The
foregoing figures indicate that he was working witli much rougher
Papers.] CURVE RESTSTANOE IN WATER PTPE 445
pipes than the writer used, niid tlie quantitative values shown on Fig.
13 indicate the same in comparison with Fig. 3.
It is evident that further experiments are desirable before precise
laws can be stated, although the qualitative results by Mr. Bright-
more and the writer agree in indicating a decreasing loss of head for
an increasing radius of curvature.
Vol. XXXIV. MAY, 1908. No. 5.
AMERICAN SOCIETY OF CIVIL ENGINEERS
I N S T 1 T U T E D 1 8 5 2
PAPERS AND DISCUSSIONS
This Society is not responsible, as a body, for the facts and opinions advanced
in any of its publications.
NOTES UPON DOCKS AND HARBORS.
By Luther Wagoner, M. Am. Soc. C. E.
To BE Presented September 2d, 1908.
During the year 1907 the writer visited the principal ports of
Europe and the United States for the purpose of procuring data for
the preparation of a report upon the future needs of San Francisco
in the matter of port improvements.
For the foreign work he had exceptional facilities for observing
completed works and receiving information concerning new or pro-
jected work. As a result, he obtained a large quantity of technical
literature, maps, plans, and photographs, as well as notes, and, be-
lieving that some of the data obtained may be of general interest to
the profession, he lias prepared the following paper.
Comparison of European with American Harbors.
A striking difference in the ground plans of port works is at once
apparent to the visiting engineer. The development by piers or
jetties, like that of San Francisco or New York, has no parallel. Gen-
erally speaking, the European idea is one of enclosed basins, with or
without locks, as tidal conditions may require. In the Mediterranean,
where the tide ranges from 10 to 20 in., there is usually no protection
Note. — These papers are issued before the date set for presentation and discussion.
Correspondence is invited from those who cannot be present at the meeting, and may be
sent by mail to the Secretary. Discussion, either oral or written, will be published
in a subsequent number of PiorerdiiKjs. and. when finally closed, the papers, with
discussion Iti full, will be iiublished in Tra^isactioiis.
Papers.] NOTES UPON DOCKS AND HARBORS 447
from the sea, so a mole or breakwater is built and behind it a safe
harbor is created by dividing up the protected area into basins
separated by solid filled piers, usually from 300 to 400 ft. wide. Upon
these piers there is first a space of from 20 to 25 ft. for cranes and one
railway track. Next are the sheds, from 75 to 130 ft. wide; then there
is an open space between the sheds for two railway tracks, and a wagon
road between them. At Naples it was necessary to build such a wall
in 110 ft. of water; at Genoa, in depths of from 50 to 70 ft., and at
Marseilles from 60 to 75 ft.
At cities like Antwerp, Rotterdam, Bremen, and Hamburg, on
tidal rivers, the problem has been one of obtaining the desired area by
dredging out basins and enclosing them with quay walls, leaving suffi-
cient space for railway connections, sheds, warehouses, and roads, the
whole being arranged so as to facilitate business. In this matter it is
specially noteworthy that railway connections have been provided at
all points, and, generally speaking, freight can be transferred directly
from the ship to the car or vice versa, thus avoiding delay and extra
handling.
Liverpool, which is essentially a receiving and forwarding port,
has perhaps the best arrangement of railways and stations. In a
length of 6 miles of water front there are ten or more great railway
freight stations, all being just at the rear of the docks. In point of
efficiency of belt-railway service, there is nothing at present in the
United States that is comparable with that of any first-class European
port. Within the City of Philadelphia there are more railway lines
connecting manufacturing establishments with the various roads than
in any other city of the same area, but, on the other hand, the rail-
ways own and control about 80% of the available water front. New
York has no belt-railway, and it is doubtful if it will ever have one.
as the price of land required for it is prohibitory. San Francisco is
fortunate, in this respect, as the State owns the water front, along
which thei"e is a street 200 ft. wide, and upon which there is a State
belt-railway. If the recent plans for the port improvements are carried
out, the new street along the water front will have a width of 350 ft.,
upon which there will be ample room for belt-roads, warehouses, and
railway freight stations, as well as street cars and other vehiciilar
traffic.
In Europe the systematic planning of new work is especially note-
448 NOTES UPON DOCKS AND HARBORS [Papers.
worthy. For example, in Antwerp, a broad, comprehensive scheme of
port enlargement has been carefully prepared, and is of such magni-
tude that it will require many years for its execution. The Board of
Control has acquired the lands, and planned the roads and rail con-
nections long in advance of actual needs, thus permitting its orderly
execution without regard to any vested interests. As the city grows
up around the new port, it will not have to make expensive changes,
Similarly, Rotterdam has planned a gigantic basin where it is in-
tended to dredge 650 acres to a depth of 40 ft. and deposit the soil on
the low lands below. It is estimated that the completion of this work
may require from twenty to thirty years. All the larger ports in
Europe are planning and executing systematic extension of their
facilities to hold their present and secure a share of expected increased
trade. Coincident with such work, much attention is given to making
the city attractive, a place where one would like to live, and where a
visitor would like to go again. They have, in general, a good ad-
ministration, and are able to select and keep employed men of ability
to administer the public utilities. As a rule, they look further aheavl
than Americans; in other words, they think more before taking action.
Statistical Chart.
Among the duties imposed upon the writer was the reqiiest to try
and forecast the amount of the future commerce of the port of San
Francisco, and plan improvements ample for such purpose, say fifty
years hence. The method of investigation and the results are shown
upon the diagram, Plate XL VIII. After a preliminary study of the
data, it was found that, owing to the rapid increase in the quantities
platted, and the natural irregularities of the subject, the ordinary
method of showing the time relation was not suitable for prediction
purposes, and the logarithmic method was used. In the diagram, Plate
XLVIII, the year 1700 is zero, 1800 is 100, and 1900 is 200, and the
logarithms of these numbers were used for the time scale. Four vor-
tical scales of 1 to 10 were drawn, so as to cover all the data used
without confusion of lines. In such a diagram an inclined line de-
notes an exponent; for example, the average line drawn through
"Value of Merchandise Exports and Imports, TTnit(>d States," is the
graphical representation of
Average value = 0.0000244 (Year, ITOO)*'""
♦
Foldout
Here
♦ ♦
♦
: XLVIII.
M. SOC. 0. E.
, 1 908.
NER ON
D HARBORS.
_1840 \~
=19p(
)
— b
— t
f.
,
-z
1
— ^.
— «
]
•■r
f.
sir
^
^
— 1-
9
^^
~
_
■
' * /•
\
■";• *
■ *
' ■ '»
)
■ ' -r
1
-.-»■
■
I
:■':'•.
;i
5-
■■ ■ ' f
- *
■:';
.'■':■
'■'■\
•■.;»
'■■A
, >
•.1
• .• ■ ;
'•■!'"
2-
]
040
1
9p0
I
1
Papers.] NOTES UPON DOCKS AND HARBORS 449
For Hamburg's tonnage, the exponent is about 10, and for the popu-
lation of the United States the exponent is about 4. The degree of
accuracy of this method of forecasting can be readily seen by going
back, say, to 1870 or 1880, and projecting ahead to the present time.
The application of logarithmic platting to such purposes is believed by
the writer to be new.
It is commonly held by experts that the production of pig iron and
steel is a good financial barometer. The production of iron and steel
(not shown on Plate XLVIIl), the horse-power used in the United
States manufactures, and the total bank deposits in the United States
are three curves which can be almost exactly superimposed by moving
them vertically into position; in other Vv'ords, they have a common ex-
ponent or law of increase.
Some very interesting conclusions may be drawn from this diagram.
For example, up to the year 1900, London and Liverpool tonnage were
moving at a common rate of growth. London then needed port im-
provements, but expended its energy in discussion (and a very thorough
one it was), while Liverpool deepened and extended its docks; the re-
sult can be plainly seen upon the diagram after 1900. The diagram
also shows that the exponent of increase of population in the United
States is about 4; exports and imports of the United States, about G;
world's commerce, about G; United States bank deposits, about 10; the
horse-power, and manufacture of pig iron, steel, etc., about 11 to 13;
consequently, per capita, this means a rapid increase of business for
the engineer, because the increase in such activities, referred to a time
relation, is measured, per capita, by the difference in exponents.
The data relating to steamships are quite interesting. They were
compiled from a valuable report,* by Elmer L. Corthell, M. Am. Soc.
C. E. Attention is called to the very rapid and uniform increase in
the average tonnage of vessels, about 841 tons in 1873, 1 95,5 tons in
1903, and now about 2 300 tons.
The draft (loaded) of a vessel can be expressed by an equation in
this form :
Draft = K (length X breadth)^,
in which K ranges from 1 for small vessels to 0.88 for those of the
largest type. There is no doubt that K would be uniformly taken
* To the Tenth Congress, Milan, 1905, Permanent International Association of Naviga-
tion Congresses.
452 NOTES UPON DOCKS AND HARBORS [Papers.
water; they were then lowered and put down by jetting about 15 ft.
into the sand, care being taken to have the concrete filling at all times
above the surface of the water. There are no reinforcing rods, and,
when the outer galvanized cylinder fails, the structure must depend
upon the tensile strength of the concrete to resist the lifting action
of the waves, which, owing to the exposed position of the pier, may be
quite severe during a storm.
The Wear of Concrete.
Most of the quay walls observed in Europe are faced with rubble or
ashlar. In Belgium, Holland, and Germany they have a rubble facing
of hexagonal basalt blocks about 2 ft. deep, to prevent wear. In the
Albert Dock, London, a concrete non-faced quay wall has been in use
about 30 years, and, having been svibjected to much buffeting from
lighters as well as ships, it has worn away about 2 in.
Careful inspection was made as to a possible action at or near the
water line due to freezing, or wave action, of both, but nothing note-
worthy was seen. However, at Baltimore there is a noticeable excep-
tion, for, on certain bridge piers, and for a vertical range of 18 in.,
the concrete has disintegrated to a depth of several inches about at
the ordinary water line. Aside from the affected part of the concrete,
which was covered with a vegetable growth more dense than in the
lower unaltered part, nothing unusual was observed. The concrete
above and below the affected zone is good.
Various theories have been advanced to account for the decomposi-
tion. The most plausible one is that with a small tidal range there
is a destructive action by the waves lapping the affected zone, and this,
perhaps, is assisted by ice action. None of the theories suggested,
when weighed and considered in reference to similar structures else-
where, appears to the writer as tenable. Believing it worthy of investi-
gation, the matter has been reported to the United States Geological
Survey, with a request for an investigation and report.
Concrete Caissons.
In Europe extensive use is being made of hollow concrete caissons,
both plain and reinforced, for breakwaters and quay walls. The
structure is towed into position and sunk, after which the hollow cells
are filled. Some of those used for biu^ikwaters weigh more than 5 000
metric tons.
Papers.] NOTES UrON DOCKS AND HARBORS 453
At Rotterdam, caissons 131.2 ft. long, and having a width of 32 ft.
at the base and 16 ft. at the top, and 43 ft. high, were being used. A
middle division wall through the length, and nine cross-walls, divido
the caisson into twenty cells. Four such caissons were built at the
same time in an improvised dry dock. The first step was the prepara-
tion of a base, about 2 ft. thick and 32 by 131.2 ft., well reinforced,
and in this were embedded the vertical rods for the walls. The ex-
ternal side walls, about 14 in. thick over the base, were carried up witli
a batter. When the caisson walls were up to about five-eighths of their
final height, the gates were opened and the caissons were floated out to
a place in the harbor where they were secured to mooring piles. There
they were completed, meanwhile being afloat for one or two months.
As there are streaks of peat in the soil at Rotterdam, the bad parts
are removed by a dredge, and then the dredged cut is filled with sand
at least 6 ft. deeper than the base of the caisson. Then the caisson is
towed into place, and, by means of a tongue and groove on the ends,
the floating mass is brought into alignment, the free end being con-
trolled by tackle. Next, by opening valves, the caissons are sunk on
the prepared bed of sand, after which the water is pumped out of the
front row of cells and these are filled with concrete; the rear row of
cells is filled with sand to save expense.
In the older construction, the site was dredged, then a brush-
mattress facing was placed, and this was allowed to stand for one or
two years to secure thorough settlement of the mass on and to the
rear of the mattresses. Afterward wood piles were driven through the
mattress and, by using a special diving bell, were cut off and capped
below low water; then they were decked with wood or reinforced con-
crete upon which was built the quay wall. The floating, reinforced
concrete caisson method was stated to cost less per linear foot than
for piles decked with concrete and more than for piles decked with
wood. Practically, the cost may be said to be the same, with the de-
cided advantage of a nearly monolithic wall.
Where rock is convenient, this method might be used with ad-
vantage : Having made the dredged cut, next place along the front line
of the caisson one or more rows of piles, which might be driven to, or
cut off, say, 2 ft. below, the grade of the bottom of the caisson; and
then rock fill to grade; the object of the piles covered by rock would
454 NOTES UPON DOCKS AND HARBORS [Papers.
be to prevent any rotation of the concrete block around the outer toe
due to a thrust from the shore side.*
COMPRESSOL.
In Paris the writer witnessed a demonstration of the Compressol
method of preparing foundations. By a sort of pile-driver, a heavy
conical weight is dropped repeatedly upon the soil, and, when the de-
sired depth is obtained, small stones are dropped into the hole, and,
by special forms of conical weights, are forced down and out into the
soil, after which concrete is rammed into place by the same means.
A completed pile will generally be 1 m. in diameter and have a bulb at
the base.
One contractor in Belgium has eighteen of these machines at work.
There are many places where such a system might be used; its special
value would appear to be in a firm soil of loam requiring piling, and
where the pile heads would be above the permanent water plane.
AVhether, in point of economy, it presents any advantages over some
of the patented American systems is not known to the writer. It is
asserted, by those advocating the Compressol system, that, owing to
the thorough compression given to the grovmd, both laterally and ver-
tically, combined with the mushroom-shaped base of the pile, it is
capable of sustaining two or three times as much load as piles used in
American systems. Certainly there must be considerable merit in it,
otherwise it would not be used so extensively.
Wood Piles Driven at an Angle.
At Bremen, and notably at Bremerhaven, it is the practice to con-
struct much of the new work in the dry. The area to be enclosed is
stripped, by land dredges and cars, to 3 or 4 ft. below low water, and
is kept dry by pumps. Along the proposed line of quay wall, two
single-rail tracks are laid, about 33 ft. apart; these serve to carry a
pile-driver which traverses a carriage supported by the two rails. Thft
pile-driver is arranged to swivel in two directions; thus the driver can
be placed with great precision and dispatch, and piles can be driven
at any desired batter. It is the practice to select long piles, and first
drive each tenth bent of piles. The ways are marked with a metric
* A good illustrated technical description of the work at Rotterdam may be found in
De Ingenicur, July 20th. 1907; The Hague, Holland. This has not yet been translated into
English.
Pi'I'f'^'] NOTES UPON DOCKS AND IIAKBORS 455
scale, and an attendant records the position of the pile at each fifth
or tenth blow. From these data piles of suitable length are selected
for the intervening nine bents, and a similar record of driving is
kept. Should one or more piles in a group settle too much during
the last ten blows, a longer pile is driven in the bent or in the ad-
joining bents to give additional bearing power. The bents, when
driven, batter about 1 on 5, like the letter A. At the cross of the A,
two strong timbers are bolted to the framed piles, and longitudinal
wales are bolted to the i)iles and side pieces, and a 6-in. wood floor
completes the foundation. Upon this fovmdation a quay wall of rubble-
faced concrete is built, and is bonded to the rear piles by tension rods,
after which the area is opened and excavated to the full depth by
dredges. A construction of this kind resists most effectively the thrust
from the landward mass of earth, the outer piles being compressed and
the rear piles in tension.
Mr. Claussen, Dock Engineer at Bremerhaven, says that he con-
siders 15 tons per pile a safe load when used in tension. A number
of long walls, such as the sides of a dry dock, quay walls, and locks
in use for ten years, were remarkably straight, and offered strong evi-
dence as to the value of this system of construction. This could not
be used if limnoria or teredo were present, unless the piles in the outer
row were covered by a concrete wall; but it might have application
for mooring bits, etc., where the piling is protected, and perhaps would
be advantageous where it is required to erect a temporary bulkhead
and load the ground landward for a year or more, so as to consolidate
it before commencing the permanent construction of a quay wall.
Cranes.
In nothing is the difference between the United States and Europe
so marked as in the non-use here and the general use there of power
cranes, usually hydraulic, but often electrically operated.
It is quite common for a merchant to visit Europe and, having
noted the many excellent things to be seen, quite naturally think that
among the improvements required in the United States are cranes.
In Europe several thousand cranes are installed; upon an average
there is one crane to 283 ft. of quay wall, and their usage is quite
variable.
456 NOTES UPON DOCKS AND IIAKBORS [Papers.
At Marseilles, in 1903, thirty-four hydraulic cranes, having a
capacity of 2 750 lb., worked 121 days per year for each crane, on a
J)-hr. basis, and averaged 25.2 loads per hour. Ten cranes of double
power, but working at one metric ton, worked 115 days; and working
at 3 tons, 16 days each per year.
The whole number of loads was 1 116 980, which gave an income of
166 312 francs, or 2.92 cents per load. The average income of a crane
was about $745 per year, which includes the power and the crane
operator. This port has perhaps a more intensive use of cranes than
those farther north, where generally only one crane out of four or five
is observed to be working.
At London it is alleged that cranes do not pay interest upon their
cost, but the ship owners insist that the dock owners have them and
do not use them, except perhaps for a small part of a cargo.
It is possible that the crane idea is a survival from the days of
sailing ships, when they were first introduced and were really re-
quired; next they were copied by other places, and by sheer inertia
dock owners persist in having them. The people of the United States
are quick to seize and appropriate a good idea, and the fact of the
non-use of cranes, compels a strong belief that the appliances used —
the ships' tackle and the stevedores' hoists — are ample. It has been
asserted that a difference in the nature of the business done in the
different countries is responsible for the general use of cranes abroad;
but this does not appear to be a reasonable view of the matter.
The writer does not wish to give the impression that cranes are not
useful; on the contrary, he believes that a partial adoption of the plan
in the United States — to the extent, at least, of having wharf cranes
which would serve to lift anything in excess of the capacity of a
ship's tackle — might prove useful.
At Liverpool many cranes are supported upon the top of the ware-
house front wall and a rail upon the peak of the roof. This is a very
excellent disposition, because the crane is always out of the way.
Dock Strikes.
There is and has been much troiiblo at many ports in Europe
from labor strikes, and, upon the whole, these arc probably worse than
any that have happened in America.
It is difficult for a stranger to form an accurate estimate of this
Papers.] K0TK8 Ul'ON DOCKS AND llARBOUS 457
subject, because he hears various versions of the cause and nature of
the trouble.
The writer questioned the officials of the ports visited, and, as n
check, obtained the views of the marine underwriters and sometimes
the Jesuit Fathers, who are usually in a position to estimate the
troubles impartially. The general unrest appears to have below it a
raising of the standards of living, for the cost of living and the wants
of the laborer have increased faster than his wages. On the other
side, the employers assert that, in view of the serious competition be-
tween ports, a small amount of extra cost will cause a diversion of
business, therefore they oppose an increase of wages.
The nature of the work is irregular, there are periods of great
activity followed by lessened opportunity for work. Genoa has been
greatly troubled in the past by strikes, and the present port governing
board, which is closely modelled on the lines of the Liverpool Dock
Trust, has assumed that it has the power to settle such questions by
creating a permanent force of laborers who perform any sort of service,
from discharging cargo to road making, if required. The board takes
on extra men for short periods to cover emergency cases. The laborers
receive less pay than men engaged by private employers, and it is said
that, on account of a strong union organization, they do less work.
The ovitside criticism was, that the laborers practically dictated hour'3
and terms to the dock board. The experiment is an interesting one,
and its outcome will be a matter of interest.
During the writer's visit, a mild strike was in progress at Le Havre,
and at Antwerp a severe one which required the importation of some
2 000 English strike breakers, who,' for their protection from assault,
were housed on vessels in the harbor. In August the strike culminated
in burning the timber yards and required calling out the troops in
order to save the city from fire and quell the rioters.
To the writer, the wages seemed to be too low, but unless concerted
action were taken by all the competing ports, it would be difficult to
effect a raise. It does not appear that the form of government has
any very decided influence upon strikes or violence arising therefrom.
The striker is usually a voter, and some one in authority may need
his vote. About the only safe deduction that can be made is that a
small aggressive minority comes pretty near getting all it desires.
458 NOTES UPON DOCKS AND HARBORS [Papers.
Average Data.
The following average data concerning foreign ports, compiled
from a paper,* entitled "Results of Investigation Into Cost of Ports
and Their Operation," by Mr. Elmer L. Corthell, and corrected by the
writer in a few particulars, presents in a summarized form informa-
tion of considerable interest:
The ports included are London, Liverpool and Birkenhead, Glas-
gow, Bristol, Hamburg, Rotterdam, Le Havre, Dunkirk, Bilbao, Ant-
werp, Bremen and Bremerhaven, the Tyne Ports, Marseilles, Amster-
dam, Lisbon, Bombay, and Buenos Ayres.
Total cost of port improvements to 1906 $764 388 000
Registered tonnage, entered and cleared in one year
(about 1905-1906) 185 652 000
Goods dealt with in one year, 1905-1906, in long tons
of 2 240 lb., approximately 143 000 000
Gross revenue in one year (about 1905-1906) 58 206 000
Expenses " " " " " " 29 003 000
Net revenue " " " " " " 29 203 000
Gross revenue per registered ton " " 31.4 cents
Gross revenue per long ton " " 40.6 cents
Quayage length, in feet 1 192 000
Quayage length, in miles 227
Approximate length of rail, in miles 930
Length of rail divided by length of quayage 4.11
Ratio of area of sheds to quayage (44 467 770 sq. ft. of
sheds to 1 067 120 ft. of quay) 41.1 to 1
Average weight of goods dealt with per year per linear
foot of quay, in long tons 120
Percentage of gross income on capital cost 7.615%
One crane to each 283 ft. of quay wall.
General Reflections on Commerce.
The greatest factors to-day in the material and moral development
of the world are transportation and commerce. By their agency, people
and their products are moved from a region of a lesser to one of a
greater use and demand. They are the greatest of all the civilizing
* Proceedings of Permanent International Navigation Congresses, Brussels, 1907.
Papers.] NOTES UPON DOCKS AND HARBORS 459
agencies, because they promote an exchange of thought as well as of
commodities.
The growth of modern commerce is closely interwoven with the
development of the steam engine, railways, and electricity. It is a
question of power and its applications, and its present enormous di-
mension is largely the work of the engineer. Its growth has been
phenomenal, and is ever increasing; it is far more rapid in its rate of
increase than that of population, which means increased wants upon
the part of the people, and increased ability to buy and to enjoy. Its
future is a question of great philosophical interest; but, until the people
of the world are raised to the general level of intelligence of the more
favored nations, it is reasonable to believe that its march will continue,
and that day is so far distant that it does not immediately concern the
present age. Until then, the signs point to an ever-increasing scope in
the functions of the engineer.
Vol. XXXrV. MAY, 1908. No. 5.
AMERICAN SOCIETY OF CIVIL ENCmEERS
rNSTITUTED 185d
PAPERS AND DISCUSSIONS
This Society is not responsible, as a body, for the facts and opinions advanced in
any of its publications.
THE FLOOD OF INIARCH, 1907,
IN THE SAORAIMENTO AND SAN JOAQUIN RIVER
BASINS, CALIFORNIA.
Discussion.*
By Messrs. Lcttirr Waoonrr, IT. IT. Wadswortii, and George L.
DiLLMAN.
Mr. Wagoner. LuTiiER Wagoner, M. Am. Soc. C. E. (by letter). — This paper is an
extremely valuable eontribution, and presents the main facts of the
flood with great clearness. The opening statement, that it was one of
the most destructive floods that has ever occurred in California, while
probably correct in a financial sense (and due to the fact that there
was more property to be damaged than at previous floods), implies that
it was about the greatest flood on record. The authors say:
"It is doubtful if any combination of causes or conditions will
ever produce a larger rate of delivery of water to this valley for a
4-diiy ]>oriod than occurred during the flood of March, 1907."
The writer believes that it would be unsafe to accept this statement
as a basis for planning reclamation and flood prevention, unless it is
qualified by a large factor of safety. It is generally believed that the
flood of 1862 was greater in volume of water discharged into the basins
and bay. In 1890 the writer, while engaged upon plans for the La
Grange Dam on the Tuolumne River, found a well-preserved record of
the 18G2 flood near the present dam and 70 ft. above the bed of the
stream. The record was in the shape of rounded pieces of wood and
* Continued from April, 1008. Procceilinris.
Papers.] DISCUSSION ON CALIFORNIA FLOOD 461
bark, fir, pine, tamarack, and juniper, showing that these pieces came Mr. Wagoner,
from tlie higher regions. They were found in a talus of loose
rock, and were doubtless carried into the void spaces by eddies and
lodged there. Almost opposite, and across the river, a similar deposit
was found, and at almost the same level. This led to a search along
the river gorge above, where several similar records were found. Levels
were taken, and connected with several cross-sections, and these, com-
bined with the known high water at La Grange, about 1 mile below the
dam, where the channel is wider and more regular, led to the conclusion
that the maximum discharge was 130 000 cu. ft. per sec. This was
based on the slope and Ivutter's formula (n = 0.040), and the dam was
planned to be able to discharge that volume over it; this corresponds
to a run-off of 8G.7 cu. ft. per sec. per sq. mile.
In 1895 the writer found a similar record on the middle fork of the
American River near Volcanoville, from which, by the same methods,
a run-off greater than 100 cu. ft. per sec. per sq. mile was deduced.
(The original notes of both the foregoing records were destroyed in the
San Francisco fire, two years ago.) Estimates have appeared in print
in which the flood flow was given for the whole basin of the American
River at 250 000 cu. ft, per sec, and even more. The record given
above, applied to the whole water-shed above Fair Oaks, would give a
discharge of about double the authors' 93 000 cu. ft. per sec.
While it may be true that a flow of 782 000 cu. ft. per sec. for 4
days may not be exceeded, there are two points to be considered. The
flow from the San Joaquin region might occur as in 1862, and in
combination with a 1907 flood on the Sacramento, in which case the
quantity would be greatly exceeded. Again, suppose the rivers were
leveed in accordance with the plans of the Engineering Commission
of 1904, it would not require a 4 days' sustained flood to overtop the
levees, and the probabilities are always in favor of the shorter but
perhaps more intense run-off.
There is an average difference of a month in the melting of the
snow upon the Columbia and Snake water-sheds, yet in 1900 it melted
on each at the same time, with the result of backing up the Willamette
and flooding Portland to a depth of several feet. This flood was sus-
tained for more than two weeks.
The writer concurs in the conclusions of the authors, that relief
from damage by floods must be sought in storage to relieve the peak
of the discharge. Storage of debris is equally important, if the bed of
the stream and navigation interests are to be preserved, and future
studies should be upon the lines of effecting both water and debris
storage.
It is the writer's belief that this can best be accomplished by loose-
rock dams, backed with earth and waste on the up-stream face and
with the down-stream face secured to the mass by suitable anchors, so
462 DISCUSSION ON CALIFORNIA FLOOD [Papers,
Mr. Wagoner, fis to allow the passage of floods over the crest of the unfinished dam
during construction. When completed there would be an ample spill-
way around the dam, so that it could never be overtopped. Such dams
would have to be of great height, from 400 to 500 ft., or even greater,
because they would usually be located in gorges, and it might require
from 300 to 400 ft. of permanent elevation to create a sufiicient reser-
voir area, after which the increase of storage would be rapid. The only
serious objection to such a type is the cost, but it can be shown that in
the end it would be economical, because the desired regulation could
thus be obtained (and, incidentally, the storage of debris), as well as
power and irrigation.
It is beginning to be recognized that the proper treatment of this
subject is a serious matter, and that the cost may reach $100 000 000
or more. From the analysis presented in the paper, it appears that
there should be a storage of about 3 000 000 acre-ft. in order to give the
required relief on the Sacramento water-shed alone. Such storage could
be valued as follows: (a) Relief of peak load and flood prevention;
(h) storage of debris; (c) preservation of the channel of the river; (d)
irrigation; and (e) power. Wlien all these possible uses are admitted
and properly valued, it can readily be seen that a high cost per acre-
foot of storage is permissible.
Mr. Wads- H. H. Wadswortii, M. Am, Soc. C. E. (by letter). — Although dis-
astrous to the agricultural interests of so large an area, and to all the
transportation lines of the valley, in some respects it may be said that
this flood occurred at a very opportune time. The reclamation of the
overflowed lands of the Sacramento and San Joaquin Valley has
become a subject of vital importance to the future development of
California, and the newly-awakened interest in the improvement of the
navigation of these streams, and the movement toward the proper
correlation of the various interests affected by the flow of the streams,
from their sources in the mountains to their discharge through the
rjolden Gate, make the new standard set by this flood of great im-
portance.
The country is to be congratulated that the Geological Survey had
a sufficient number of gauging stations established to obtain so many
data in regard to the flood; and the authors are to be complimented on
having presented them so promptly in such shape as to be of practical
use, and show the magnitude of the problems involved.
A press of work, in connection with surveys looking to the regula-
tion and improvement of these rivers, prevents the writer from discuss-
ing at this time more than one or two of several points or questions
which have occurred to him, and these only very briefly.
As stated by the authors, previous estimates of flood flow of the
Sacramento River have been greatly exceeded during this flood. In
the case of tlie Yiiba River, the maximum flow which has been assumed
worth.
Papers.]
DISCnSSION ON CALIFORNIA FLOOD
4G3
since the inception of the project for restraining debris in the bed of Mr. Wads-
the stream, and which was used in designing the several works forming
part of the project, is 125 000 cu. ft. per sec, or 25% in excess of the
maximum observed flow at the gauging station of the Geological Sur-
vey. Before the failure of the dam, known as "The Barrier," this
structure served as a weir for measuring the flow of the river, though
its coefficient was very uncertain after it became backed up with tail-
ings to its crest. The high-water marks left by the river during the
night when the failure occurred indicated that the assumed maximum
was nearly if not quite reached. Based on observations and estimates
of flow at this point and at a few points on mountain streams carrying
the drainage from comparatively small areas, Table 29 was prepared by
the writer as a guide in determining the required capacities of s^jill-
ways or canals to carry flood water around or away from dams erec+ed
for the storage of mining tailings.
TABLE 29. — Assumed Maximum Eun-off, Sierra Nevada Streams,
Based on the Flood of March, 1907.
Maximum Run-off, in Cubic
Maximum Run
-OFF, IN Cubic
Drainage
Feet Per Second.
Drainage
Arka, in
Square
Miles.
Feet Per
Second.
Square
Mii.es.
Areas below
Areas above
Areas below
Areas above
elevation
elevation
elevation
elevation
4 000 ft.
4 000 ft.
4 000 ft.
4 000 ft.
1
544
408
40
8 6.50
6 490
2
915
686
50
10 200
7 670
3
1 340
940
60
n 700
8 800
4
1 540
1 1.50
70
13 200
9 860
5
1 820
1 360
80 .
14 500
10 900
6
2 090
1 560
90
15 900
11 900
7
2 340
1 760
100
17 200
12 900
8
2 590
1 940
200
28 900
9
2 830
2 120
300
39 200
10
3 060
2 290
400
48 700
30
5 140
3 H60
500
57 500
30
6 970
5 230
1000
96 800
Table 29 is applicable to drainage areas of the character of the
Bear and Yuba Rivers, and of such portions of other drainage areas as
do not contain broad flat valleys. Of course, it would not apply to
portions of the Feather River drainage area, containing the Sierra,
American or Indian Valleys, or Big Meadows.
Considering for a moment the effect of mining debris on floods, it
should be borne in mind that only on the Yuba River is it likely that
the flood plane will continue to rise materially owing to this cause.
The beds of the American, Bear and Feather Rivers (Feather above
the mouth of the Yuba) have reached as near a state of equilibrium
as is common for streams flowing through alluvial formations. The
curtailment and regulation of hydraulic mining has largely .stopped
4G4 DISCUSSION ON CALIFORNIA FLOOD [Papers
Mr. Wads- the accumulation of tailings in the torrential tributaries of the Yuba,
worth, ^j^^ many of the canyons of these tributaries, which a few years ago
were filled with tailings to a depth of from 20 to 60 ft., have been
scoured out to bed-rock. Below the gauging station of the Geological
Survey, at The Narrows on the Yuba River, there is a vast deposit of
mining tailings standing on slopes which succeeding floods will con-
tinue to readjust; but any further extensive rise of the flood plane at
Marysville does not seem probable.
In connection with the subject of partial control of the flood flow of
the Sacramento River by reservoirs, it is interesting to note that the
total capacity of five flood basins of the Sacramento Valley, as com-
puted by the authors, amounts to 3 731 000 acre-f t., and that the effect
of these basins was to delay the arrival of the flood crest at Rio Vista
about 4 days. Had there been levees sufficient to confine the river to
the channels, how much higher stage would have been reached at this
point ?
Of the storage reservoirs located and surveyed by the United States
Reclamation Service, the total estimated capacity is 4 817 000 acre-f t.,
or about 1 000 000 acre-ft. in excess of that of all the Sacramento Valley
flood basins. The latter are much more likely to be empty, or at least
to have considerable capacity for the storage of flood waters when a
flood occurs, than are the former, since, owing to the uncertainty of
further large run-off before the dry season, it would jeopardize the
agricultural interests dependent upon irrigation to leave these reser-
voirs nearly empty until after the middle of March. The worst flood
of the season is likely to occur after that time, as was the case with the
flood of 1907. On the other hand, no flood may occur, as has been the
case during the season of 1908.
In whatever way the control of ordinary floods may be effected, it
will very likely be found that :
"The task of rectification and enlargement of channel necessary
to pass such floods as that of March, 1907, is so great as to make it
economically impossible."
Mr. Diiiman. George L. Dillman, M. Am. Soc. C. E. (by letter). — The conclu-
sion expressed in this paper is that mountain storage will be the ulti-
mate solution of the flood problem of the Sacramento Valley. With
this, the writer would take issue. He here states that the storage out-
lined is impracticable; also, that, if accomplished, it would prove
inefficient, insufficient, precarious, and temporary. These hard names
do not all apply to each case, but some of them apply to each case,
and all to a few of them.
The reservoirs mentioned, except Big Meadows and Clear Lake
(which will be built by private corporations for power purposes),
should never be built for flood regulation. The reasons are various.
Some of these reservoirs are located where their water capacity would
Papers.] DISCUSSION ON CALIFORNIA FLOOD 465
diminish rapidly by filling with debris, ultimately reaching zero. This Mr. Diiiman.
applies specially to the Stony and Putah Creek Reservoirs, and also
to Iron Canon.
Some of these proposed reservoirs would flood lands which are too
valuable to buy for such purposes. This is specially true of Indian
Valley, where the lands which would be flooded are the finest kind of
dairy lands, and include three small towns, with improvements which
would make the cost great. From an irrigation standpoint, this
storage is not needed, and would destroy more agricultural land tlian
it would reclaim, less the cost of reclamation.
The Big Valley Reservoir — two-thirds of all the storage proposed —
would be fed by an arid country. No doubt, its capacity compared
with its cost is quite favorable, but some water should be allowed to
pass to users between Bieber and Fall River. The evaporation would
be large, and it would probably take several years to fill it. The
authors' figures show that the 4 days' abnormal flood would fill 6% of
it, if all was stored. During part of every year, the inflow would not
equal the evaporation.
There is no reason, from an irrigation standpoint, for making the
Feather River storages. Feather River is not much used for irriga-
tion, by reason of expensive diversion. At low stages there is water
without storage for any who will divert it; and there are no adverse
claimants for it.
These storages are precarious. The high-water mark for years on
the East Branch of the Feather was made by the failure of a small
dam above Indian Valley. The flood of 1907 caused the failure of a
dam on the Yuba, when the waters flooded large areas, some going
south and breaking across Bear River, finally reaching American
Basin. The possible damage by the failure of a reservoir dam on top
of a flood can hardly be estimated.
The paper assumes the removal of water from the crest of a flood.
This would hardly be the fact. This flood's crest came after weeks of
flood, and it is fully supposable that the reservoirs would have been
filled and held full long before the time had arrived for such bene-
ficial effects. The location of these reservoirs averages more than 100
miles from the seat of damage. Wliat man is wise enough, during a
period of such storm and flood, to say when the psychological moment
arrives for closing gates and making storage?
Taking from Table 27 the volume available for storage, or the
capacity of the reservoirs, the total storage for this flood would have
been 931 300 acre-ft. The side basin capacity is given as 3 775 000
acre-ft., or more than four times the mountain storage. This basin
storage, like the mountain storage, would be largely made prior to the
crest of the flood, but there is another factor. At about the time when
the crest of a flood occurs, side levees break. In 1904, the Edwards
466 DISCUSSION ON CALIFOENIA FLOOD [Papers.
Mr. Diiiman. break, On the east bank of the Sacramento, and in 1907, the Kripp
break, on the west bank, gave great relief, as far as flood heights on
the lower river go. The first poured into the Sacramento Basin and
discharged into the San Joaquin through the Mokelumne. The second
poured into the Yolo Basin and discharged into the Sacramento
through Cache Slough. These side basins are not only storage reser-
voirs, but are great by-passes, through which flows a volume sometimes
greater than the main stream. At flood times Yolo Basin is a stream
10 miles wide, flowing rapidly. The basin relief is from flow more
than storage. It is at hand, and acts automatically at the right time.
Years ago, an avalanche of debris from hydraulic mining started
toward the valley. Mining has stopped, but the debris is still coming.
Diversion of waters, whether natural or assisted, lessens the current,
increases deposits of debris, and raises the beds of streams. This silt
problem cannot be divorced from the flood problem. As a rule, the
stream beds are rising, so that the same volume of water reaches a
height increasing with time.
From all the foregoing it would seem that mountain storage is not
advisable for flood control. The valley problem is a complicated one,
including the protection of lands, the navigation of streams, the drain-
age of flood water, and the care of the debris. Difi"erent solutions
have been proposed.
The State Board of Works, about 1890, proposed an elaborate sys-
tem of by-passes through the valley. This never met general approval.
Such an installation would increase silt deposit in the streams, raise
the flood and ground-water planes, and increase the area afi^ected by
floods. The ultimate effects would be detrimental to agriculture, navi-
gation, and flood conditions.
In 1905, a Board of Engineers recommended a plan based on con-
centration, instead of diversion, of waters. The plan met general ap-
proval as to method. The cost, however, was great, though the
agricultural land reclaimed would have been worth several times the
outlay. The interests are so many and so divided, each wanting to
benefit out of proportion to the outlay, that no action has resulted.
It seemed once that the debris problem might be divorced from the
others by a series of debris barrier dams. The failure of the first one,
on the Yuba, settled it otherwise.
The mountain storage solution has been brought up from time to
time, but has never stood close analysis. To obviate the floods by pre-
venting them, sounds all right until the illusion is dispelled by the
cost, and the amount of storage is compared with the flood volume. The
valley must take care of the floods. They will come. Mountain stor-
age increases the risk, with very small compensation in possible re-
sults.
A rational solution lies in adequate waterways, made and main-
.Papc'is.J DiyCUSSION ON CALIFORNIA i'LOOU 467
tallied by a couibinatiou of dredging and levees. If plans to this end Mr. Diliman.
could be adopted, and all future work be obliged to conform to them,
the end would be reached in time, without enormous initial outlay.
As the plan was executed, cross and other auxiliary levees could be
gradually abandoned as they became useless. River levees could be
strengthened annually by dredging, as reclamation decreased the basin
effect on floods. The levees would protect agriculture and confine the
waters. Dredging would lessen the necessary height of levees, furnish
material for them, and assist in the debris problem. The necessary
height of levees, and the depths and widths of channels are the main
questions. Rectification of alignment and foundations are important
auxiliaries. As far as the Sacramento is concerned, debris has largely
solved the foundation problem. The unstable peat bogs have been
silted up, and now sustain enormous levees on Grand Island and else-
where. The San Joaquin foundations are more serious problems, be-
cause the silt is deposited long before the waters reach the delta.
Vol. XXXIV. MAY, 1908. No. S.
AMERICAN SOCIETY OF CIVIL ENGINEERS
INSTITUTED 1853
PAPERS AND DISCUSSIONS
Tliis Society is not responsible, as a body, for the tacts aiul opinions advanced
in any of its publications.
ERECTION OF THE BELLOWS FALLS
ARCH BRIDGE.
Discussion.*
By F. W. Skinner, M. Am. Soc. C. E.
Mr Skinner ^' ^' Skinner, M. Am. Soc. C. E. — Everybody admires a great
engineering work which is designed and built conservatively, thor-
oughly, slowly, and deliberately, sometimes even ponderously. Every-
thing is done with great care and forethought, and with perfect ap-
paratus. All the appliances are complete, and the entire construction
is worked out in the most minute, most solid, and most monumental
manner.
There is no doubt that such works are great engineering triumphs,
but, in achieving them, the engineer often deviates very little from
established precedent, even though the construction is on a larger
scale than usual, and the speaker thinks that such construction does
not lead to professional i)rogress, or at least to as great an extent as
desirable.
All admire the great Forth Bridge, with its unprecedented span,
but its weight and cost were great, and it took a long time to build.
This is true of many other engineering works. The speaker has in
mind an illustration, doubtless quite familiar to many, showing that
extremely careful and costly engineering constructions are sometimes
inadvisable, and by the use of more rapid, more daring and original
methods, work can be executed which might otherwise fail.
In New York City, not very long ago, there was an important piece
of engineering work, on which, before completion, radical repairs or
* Continued from April, liX)8, Proceedings.
PLATE XLIX.
PAPERS, AM. SOC. C. E.
MAY, 1908.
SKINNER ON
ARCH BRIDGE ERECTION.
Fig. 1.— Erection of the Eads Bridge.
•xw?;?;:^
Fig. S. — Erection of the Washington Bridge.
Papers.] DISCUSSION ON JORECTION OF ARCH BKIDOli; 469
changes were found to be necessary. An estimate was obtained, from Mr. skinner.
an engineer eminent in that particular class of work, which involved
the expenditure of somewhat more than $1 000 000. Eventually, the
changes were effected for $100 000, by an entirely different method,
devised by a member of this Society. This method was considered
daring and impracticable until the contrary was demonstrated by its
unqualified success. Therefore, considering the greatest good to
humanity, the greatest advances seem to be made by, and the greatest
praise to be due to, the engineer who accomplishes the best results, with
the least money, with the gi'eatest safety, and in the quickest time.
Judged by that standard, and by the results obtained, the designers
and constructors of the Bellows Falls Arch Bridge rank very high in
bridge building.
This span of 540 ft., with its substructure, cost only $46 000, or
less than $3.50 per square foot of floor. Such a result is unprecedented
for such a long span. The erection time is also unprecedented, for it
required only 28 working days. In Europe a year or two would gen-
erally be taken in building a structure of that kind.
There are several features in the design of this arch which com-
mend themselves to every bridge engineer. Among them, the scheme
of making the crown connection with plates proved a very happy de-
vice, not usual in ordinary practice. The construction of the crown
panel, too, is advantageous.
It is to be regretted that the author did not give the details of the
members and connections, and it is hoped that he may yet present a
paper which will deal with these features.
In the erection of the Bellows Falls Arch, a happy mean was es-
tablished between a self-sustaining structure and a mass of falsework
by giving it an economical amount of temporary support, and the re-
sult abundantly justified the means.
Another feature in the erection of this arch is its exemplifica-
tion of the fast growing tendency to utilize the great advantages of
steel derrick booms over other apparatus for handling heavy steel mem-
bers. These booms were 60 ft. long, but Mr. Eights, if he were repeat-
ing the work to-day, might use 100-ft. booms, as he has in other recent
erections.
The Bellows Falls work was admirably designed, and served its
purpose thoroughly well. The highest compliment that can be paid to
the bridge is to compare it with some of the notable bridges of similar
type; because the methods used in their erection will show the ex-
cellence of this one much more effectively than any assertions.
The following description covers fairly well the erection features
of all the large arch spans which have been built :
The famous Eads Bridge — "the Father of Arches" — had three
spans, two of 537 ft. and one of 552 ft., which were noted as being
470 DISCUSSION ON EKECTION 01-' AKCII BKIDGE [Papers.
Mr. Skinner, flie longest railroad spans, and for a very long time remained the
longest arches. They were made with fonr ribs or trnsses with steel-
stave chords 18 in. in diameter, and were erected by the balanced,
guyed, cantilever system. The trusses of adjacent spans were built
out simultaneously from the piers, and were supported by an elaborate
system of guys or back-stays reaching from the successively erected
panel points of the trusses back to the tops of pairs of falsework
towers on the piers.
Each tower was a pyramidal skeleton, 50 ft. high, with a 24 by
24-in. oak mast, 12 by 12-in. batter legs, and 18 by 24-in. oak sills set
on special hydraulic jacks. The skewbacks were tied together by hori-
zontal anchors through the piers, which made them self-sustaining for
aboi:t one-quarter length, beyond which the two middle trusses were
supported by eye-bar guys with sleeve-nut adjustments provided with
very elaborate falsework svipports, set on top of the trusses to diminish
the deflection. The center panel connections were made by using the
guy adjustments and by the operation of the jacks iinder the towers,
which moved the latter vertically 6} in. Both these means together,
however, were not adequate to provide for extreme temperature varia-
tions, and there was great difficulty in making some of the connections.
The chords were packed in ice, and special sections were cut to fit the
last panels.
At the shore spans special anchorages had to be provided to secure
the ends of the back-stays. One of them was made with castings set
in a shaft excavated 30 ft. in solid rock, and the other with a horizontal
oak girder, 4 ft. square, engaging a quadruple row of 12 by 12-in.
sheet-piles driven in sand in the bottom of a deep excavation. All
four' ribs of each span were built simultaneously for the first three-
elevenths of their length, after which, work on the outer ones was sus-
pended until the center ones were completed. These then served as
platforms from which the remaining outer ones were erected. The
materials were put in place by a hand-pOwer traveler, advanced by
rack and pinion, and equipped with four derrick booms. The maxi-
mum clear height above high water is 73 ft. 9 in., and the cost, in-
cluding that of the difficult substructure and approaches, was about
$10 000 000.
Fig. 1, Plate L, is to be valued for its historical associations.
It shows the Niagara gorge with the three great types of long-
span bridges, all built without falsework. In the foreground may be
seen portions of the original railroad suspension bridge of 800 ft.
span, with steel stiffening trusses which replaced the original trusses
of wood and iron some 20 or 30 years after the construction of the
bridge. In the background is the second cantilever built in America,
the famous work of C. C. Schneider, Past-President, Am. Soc. C. E.
Partly completed, and in the same plane as the suspension bridge, is
PLATE L.
PAPERS, AM. SOC. C. E.
MAY, 1908.
SKINNER ON
ARCH BRIDGE ERECTION.
Fig. 1.— The Railroau Suspexsiox, Railroad Arch, and Cantilever Bridges, at
Niagara.
Fig. 2.— The Highway Su.spension Bridge at Niagara Being Replaced by a Steel
Arch.
I U «i
f f « 14
If l4 tr H
19. I^
Hite.
k
Patfert^
m^K^-i^S&S «t5r JSS'ITSQST '
411
S9A. ]£. AsL. S!:*t. C- £. Tlrpf ^^i;^ was aA» IkbSe ^ 1^ sasrvs^
&Esi sied giBSZT' "TjTEv^i^s. ivrm^ -^-aw ^^ -ike Bew inv <Smb^e. cosi^^Se
^ i&e «U miiiw iiiiTinin 1 ■ iM^ji sb< iffliwrTJ lie srai^f -^ ^ aai^sai^iiei
i'g»i"wiiilf»i Igr
^f^^m4 ^"^ 'wxs *«r*P!5 jr^iUTiiJ
mmbA 'Ap sane ffliMwuwi- 'hmL. as- deR- '^las mm> hg3:izzri':il iiiv' <^iseS ~ax'
f -taai pazir <^ ifc xaaAaxM^K^ ifce gaiy?- :§a' ^sf «ki ' -n~pggr;-
"ie :ji "ri I 'ii^iin icas lesTT faT.-ai"f! TW "jsg^fes v-
j7 Vfir "lJ>r ^g^Biitit-aiTV^«it*k ^gTTwa "Stos ttopt -fwyiHjrhginBi- ' s
T^Jt ■r?^? ^SETS' a 1!^^B^ ^CTCL n _- 1 -.. -£__!_ -.Irr iffi^SE SB^ ^mvsii
' : jiijri icof fi^'CE jsad SEpgwc^ T-aTH-'tMr-gF- lenia. ZI' zz. s^ob^ «Errr~nr
^ IT "n^r •n-nirgi
:2ie
Piipcrs.] IJl«CL,S«iUM ON EKECTION 01-' AKCII 15KiD(iE 471
the double-deck, 550-f t., spandrel-braced, arch span, designed by L. L. Mr. sidnner.
Buck, JVL Am. Soc. C. E. This arch was also built by the guyed
cantilever system. The trusses were assembled entirely by small over-
head steel gantry travelers, which ran on the new top chords, outside
of the old suspension bridge, and allowed the traffic to be maintained
on both tracks of the latter while the new bridge was being built.
The adjustments for the connection of the center panel were made
by slightly revolving the semi-arch trusses about their skewback pins
by using a toggle inserted in a chain connecting each top chord with a
temporary anchorage of I-beams bedded in concrete in chambers ex-
cavated for the purpose in the solid rock. The anchor chains were
made with eye-bars proportioned for stresses of 1 000 000 lb. per truss,
and were connected to parallelograms of eye-bars v/ith vertical screw
diagonals operated by sixteen men to a capstan-head, thus raising or
lowering the span, as required.
The construction of the railroad arch was soon followed by that
of another arch, for highway traffic, just below the Falls. It has a
span of 840 ft., is about 200 ft. above the water, and ^"as built in very
much the same manner, but, as there was no horizontal top chord to
form part of the anchorage, the guys for the cantilevered scnii-trusses
were lines of eye-bars attached to alternate panel points on the top
chords as fast as they were built out. These were adjusted by the
same toggle which had been used on the railroad arch.
This bridge was also built in the plane of an existing suspension
bridge, but in this case the old structure was used for the support of
the very light travelers which handled the members for the arch trusses,
and as none of them weighed more than 5 tons, the load imposed on
the old bridge was very small. The toggles were only required to
lower the semi-arches, and this they accomplished with a force of
twenty men on each. The bridge weighs 3 651 000 lb., and was erected
by 100 men in about 3 months.
The Washington Highway Bridge across the Harlem River, New
York City, has two 510-ft. main spans, each with six two-hinged plate-
girder arch ribs of 90 ft. rise and 133 ft. clear height above high water.
The ribs have a uniform depth of 13 ft., and the flanges are curved
to parabolic arcs and support transverse bents, 15 ft. apart, carrying
the floor platform. The spans were erected on framed-trestle false-
work on piles, and materials were delivered from a service track at the
skewback level, parallel to the bridge axis, to the erection travelers on
the top flanges of the arch ribs. The travelers consisted of pairs of
adjustable stiff-leg derricks which erected the six ribs simultaneously
from both skewbacks to the crown and then moved back to the ends of
the span on the permanent floor which they erected in advance. The
channel span falsework had inclined bents providing an 80-ft. center
opening for navigation. The ribs were swung by jack-screws on each
falsework bent. Each span weighs about 1 670 tons.
Pa|)(Ms.|
niscnssioN on kkkctjon of akcii bkidok
473
Mr. Skinnei.
474 ULSCUSSION ON ERECTION OE AKCli IJUllXiE [Papers.
Mr Skinner. 541-ft. arch span, 40G ft. liigli, with riveted trusses having a great rise
and carrying spandrel towers which support the roadway trusses of
about 125 ft. span. The skewback and viaduct towers were first
erected, and then the approach spans were erected on shore, at both
ends of the bridge, and launched forward by protrusion over the tops
of the towers until they projected some distance beyond the arch abut-
ments. Locomotive derricks were installed on them, and a cableway
was set up with its towers on top of the skewback towers.
With these tools, the arch members, delivered on a low-level serv-
ice bridge 100 ft. above the water, were erected, the two end panels on
each side being assembled on falsework, while the remainder was built
out simultaneously from each abutment as cantilevers, guyed to the
tops of the towers by 28 steel cables. The other roadway spans were
erected simultaneously as cantilevers. The erection lasted about 4
years.
The four 200-ft. spans of the electric car bridge across the Schuyl-
kill River, in Fairmount Park, Philadelphia, each have three spandrel-
braced riveted trusses, and were erected with the lower chords sui)-
ported on pile falsework. Materials were delivered on a track laid
on the bridge floor, and were handled by a wooden gantry traveler, 72
ft. high, with a 23-ft. overhang.
The Rochester Driving Park highway bridge across the Genesee
River, has two three-hinged, spandrel-braced arch trusses of 428 ft.
span which were erected on unusually heavy framed falsework more
than 212 ft. high, with a wide trussed opening over the river. The
truss members, having a maximum weight of 10 tons, were assembled
by a 16 by 30-ft. wooden tower traveler, 28 ft. high, with a derrick
boom on each corner. The falsework was notable for its great strength
and rigidity, equal to many permanent wooden trestle viaducts for
railroad service.
The longest arch span in Europe is that of the Bonn Bridge, (!14
ft., which was erected by 8-ton electric gantries on 7-story falsework,
112 ft. high, with two trussed openings of 102 ft. for navigation.
Upper falsework, long since obsolete in America, was built above the
curved bottom chords to provide a horizontal track at the top chord
level for the two 8-ton electric gantries by which materials were hoisted
from boats and erected. The 594J-ft. arch span of the Dusseldorf
Bridge was erected in a similar maimer, its falsework 1 eing provid:^(l
with a 164-ft. trussed opening for navigation.
The Lake Street highway bridge, across the Mississippi River at
Minneapolis, has two 458-ft. spandrel-braced arch spans. These were
erected on falsework 120 ft. high, the piles having been driven through
the ice. The falsework terminated at the curved lower chord, and the
superstructure was erected by an overhead timber tower traveler with
hoisting tackles suspended from an overhang, which traveled on the
finished deck of the bridge. This method necessitated the unusual
PLATE Ull.
PAPERS, AM. SOC. C. E.
MAY, 1908.
SKINNER ON
ARCH BRIDGE ERECTION.
'■'
k;. ;i.— Erection ov riii; i
Jo.W 1
lilllOE.
_JQ—
^^^BSBS
1
IL
^■^irr-:--
'Viritlllli
i^HI
' m / .■ ,vji,v'.
;;ri'j?«;»',}'n^-:)«'»ii'{ JH'i f S
»'^rs
S4S4^i^-
Fig. o. — Erection of the Dusseldorf Bridge.
Papers.] DISCUSSION" ON ERECTION OF ARCH BRIDGE
475
Mr. yk inner.
I£^
|l s
-x-
*- *i
476 DISCUSSION ON ERECTION OF ARCH BRIDGE [Papers.
Mr. skinuer. procedure of erecting the arch trusses from one abutment across the
entire span to the other abutment and making the final connection at
or near the skewback pin. This was accomplished successfully, and
without difficulty in adjusting the last panel members. During erec-
tion, the unbalanced longitudinal thrust, due to unsymmetrical loading
on the falsework, was provided for by very heavy inclined timbers
bracing the falsework bents diagonally from top to bottom.
The 377-ft. span of the Kornhaus Bridge, in Switzerland, was
erected on high and very expensive falsework supporting the arched
lower chords on a solid convex plank floor platform, like the lagging
for a masonry arch, above which upper falsework was built for the
erection of the horizontal roadway trusses supported on spandrel
towers, and for light gantry traveler and material tracks outside the
arch trusses.
The Panther Hollow Bridge, in Schenley Park, Pittsburg, has one
span with four 360-ft., three-hinged spandrel-braced arch trusses. One
peculiarity of this erection was that the trusses were erected from one
abutment to the crown before the falsework for the other half of the
span was built. Field connections were made with small pins at panel
points, and, after the arch was swung and these connections had ad-
justed themselves to the dead-load stresses, the joints were all field-
riveted, on the assumption that the rivets would carry the live-load
stresses of the bridge in service.
One of the most elaborate of arch span erections was that of the
Alexander III Bridge across the Seine, Paris, which has fifteen cast-
steel segmental ribs of very flat curvature. During erection these were
suspended from a movable overhead falsework span, mounted on towers
traveling transversely to the bridge axis. The falsework span was as-
sembled on shore and erected by protrusion across the river, with an
auxiliary emergency scow under the forward end. The span was
traversed by a pair of trolleys which took the arch segments from shore
and sustained them until they were assembled to the preceding ones
and were supported by temporary suspension from the trusses. After
a pair of ribs was thus simultaneously erected, the pair was swung by
slacking off the suspension, and the traveler moved two panels forward
and erected the next pair, and so on.
These examples illustrate the principal types of long-span arch
erection, and describe most of the principal structures thus far built,
giving a general idea of their structural characteristics and of the
time and cost of erection. Only two or three of them have spans ex-
ceeding that of the Bellows Falls Bridge, and certainly none of them
was erected with anything like its economy, or with as small a force
as 36 men, or in so short a time as 28 days. These figures and the total
cost, contrasted with those of the other bridges, pay a higher tribute
to the skill and covirage of the designer and erector than any mere
compliment or admiring criticism.
PLATE Llll.
PAPERS, AM. SOC. C. E.
MAY, 1908.
SKINNER ON
ARCH BRIDGE ERECTION.
Fig. 1.— The Erection of the Fairmount Park Bridge, over the Schuykill River,
IN Philadelphia.
Fig. 2.
-The Erection of the Rochester Driving Park Bridge over the
Genesee River.
PLATE LIV.
PAPERS, AM. SOC. C. E.
MAY, 1908.
SKINNER ON
ARCH BRIDGE ERECTION.
Fig. 1.— The Erection of the Lake Street Bridge, over the BIississippi River,
AT Minneapolis.
Fig. 'i. — The Erection of a Half Span of the Panther Hollow Bridge.
PLATE LV.
PAPERS, AM. SOC. C. E.
MAY, 1908.
SKINNER ON
ARCH BRIDGE ERECTION.
Fig. 1.— Erection of the Kornhaus Bridge.
Fig. 2.— Erection of the Kornhaus Bridge.
Vol. XXXIV. MAY, 1908. No. S.
AMERICAN SOCIETY OF CIVIL ENGINEERS
INSTITUTED 185 2
PAPERS AND DISCUSSIONS
This Society is not responsible, as a body, for the facts and opinions advanced
in any of its publications.
SAFE STRESSES IN STEEL COLUMNS.
Discussion.*
By William Cain, M. Am. Soc. C. E.
William Cain, M. Am. Soc. C. E. (by letter). — In considering the Mr. Cain,
merits of any new colnran formula, it is well to ''take stock" of what
we have that is sound and useful, and particularly to compare, side
by side, correct theory with experimental data.
The "ideal column" is a prismatic, homogeneous column, without
initial stress, having the resultant load applied at one end, in the
direction of the straight axis, passing through the centers of gravity
of the cross-sections. Although there are no ideal columns in practice,
the theory pertaining to them is absolutely essential in order to under-
stand fully the behavior of actual columns, or those which are not
straight, not homogeneous as to material, strength, modulus, limit of
elasticity, and perhaps with initial stress, besides eccentric applica-
tion of the load.
Two diagrams, Figs. 23 and 24, are submitted; these are repro-
duced from the discussion by A. Marston, M. Am. Soc. C. E., on the
writer's paper,t "Theory of the Ideal Column." In these diagrams,
showing the results of Tetmajer's tests on columns, both of wrought
iron and steel, the ends being pivoted, three curves are drawn. The
upper curve, partly dotted, is drawn from Euler's formula, the full
line is from Mr. Marston's formula, given on the figure, and the re-
maining dotted curve is from the parabolic formula of the late J. B.
Johnson, M. Am. Soc. C. E.
* Continued from March, 1908. Proceedings. -
t Transactions, Am. Soc. C. E., Vol. XXXIX, pp. 109 and 111.
^ I* ?* ••*
^ -^^
'%=
^r
- -'-c _ -!T -tr
:fr-
ji
- S -c -
^ ^ ^ ^ ~
i = ~ ^ ^ ^ —
:i » =^
i ^ < f ^ . .-.
3 S Jj — ~
<~ ~ ^ rs -
J> 2
-' i
•H'^^
7. * 'v ' *■
■TTi
«
Papers.] DISCUSSION' OH SAFE STRESSES IN' STEEL COLUMN'S
ULTIMATE STfiEHOTH IN FOUN08 PER Sa «M.
= 4 g ' )
ill
479
Mr. Cain.
-'X-
n ^^
--^
/7<'
>
/ f
-~
/
4-i
s-
2
>
/
<
2 ^ ^1^2
i
■»
§ ^ r z i: >
4 - a 'J^ -^ i:
^ - ^- ^ ^ ^ -
SS'— - ^ 'i r
_ J^ 1 X ^ - n
/
■_
J
o^ 5 - :: I
If S-^l
IT
:■
I
/
^2 ?;:2=
,; ■!
■| 1
4:78 DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS [Papers.
Mr. Cain.
Papers.] DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS
479
Mr. Cain.
482 DISCUSSION ON SAFE STRESSES IN STEEL COLUMNS [Papers.
Mr. Cain. Johnson derived a similar formula in "Modern Framed Structures.''
When c^ = 0, an exact theoretical form is reached by replacing 8 by
TT".
Exactly as in the preceding case, to apply this formula to the
actual column — ^ ^^^^ have to be taken as constant. Unfortunately,
P
to find the value of -^ for a given column, a quadratic must be solved ;
hence the formula was not easily adaptable to computation and, con-
sequently, was laid aside.
As Rankine's formula, which is of the form,
r _ s
1 + c
7-2
is sometimes spoken of as a rational formula for the actual column,
it may be well to consider it briefly.*
As this formula does not suppose the load to be applied eccen-
trically, but does suppose bending, the latter must come from crooked-
ness or lack of homogeneity; for, as has been seen, for values of —
less than pertain to Euler's formula, there can be no bending for
the ideal column, and it is for just such lengths that Rankine's formula
has been mainly used. Comparing it with the preceding formula
when d = 0, it is seen that c cannot be a constant, since it is propor-
tional to is j) , or the maximum unit stress at mid-length, on
the concave side, due to flexure only. In fact, in the derivation of
Rankine's formula, the assumption is made, that the deflection varies
as jr- S, whereas the very theory of beams to which reference is made,
shows that 8 must here be replaced by the maximum unit stress due
to flexure only, or by {8 — —J . This leads again to the preceding
form of formula.
The Rankine formula is thus irrational, and it is surprising that
it should still be used in such problems as, for a given column and an
assumed load, to compute 8, assimied to be the total maximum fiber
stress. Mr. Marston's formula, replacing 8e by 8^ should be used in
such problems. As Rankine's formula can be made to fit the tests
very well, it has been used extensively; but it must be relegated to the
class of empirical formulas, like the parabolic, that fit the tests equally
well and are more convenient to use.
The writer was very much impressed with the straight-line for-
* This part of the subject was discussed so thoroughly by Henry S. Prichard,
M. Am. Soe. C. E., in Engineering Newfi for May 6th, 1897, that an apology seems to be due
for discussing it again.
Papers.] dISCUSSTON ON" SAFE STRESSES IN STEEL COLUMNS 483
mulas of Thomas H. Johnson, M. Am. Soc. C. E., when they were Mr. Oain.
first published, but is leaning now to the use of the parabolic formulas
of the late Professor J. B. Johnson, the curves corresponding being
made tangent to Euler's curve. In this way results are obtained which
can be used in testing the strength of existing structures, as well as
in designing. If, in designing, it is desired to exclude columns hav-
l
ing the ratio, — , greater than 100 or 120, say, a simple clause to that
effect in the specification should sufiice.
It will be seen from this, that the writer thinks that the author's
intention can be carried out in a different way than in using the
circular curve. If all the innumerable curves that have been proposed
could be swept away and a curve be drawn by hand, steering a middle
course between the plotted points (noting carefully, also, the lowest
points), it would answer the purposes of the designer as well as a
formula. For competitive designs, however, a formula is almost im-
perative. It should not give as large values, for very short columns —
especially with riveted or butt ends — as the straight-line formulas.
The imperfect "fixing" of the ends of some columns leads to such
indefiniteness that it is customary, perhaps, to use the formula for
hinged ends for all cases, though some allowance is often made for
riveted ends or butt joints.
There is some indefiniteness, too, in the case of pin-end columns,
on account of the friction of the pin; so that, for such columns, an
eccentricity different from that used for pivoted ends, would have to
be assumed, perhaps, in applying the exact formulas of Mr. Marston.
In all cases, the details of a built-up column must be designed care-
fully, for the details, rather than the length, are frequently the main
factor in determining the strength of a column.
Vol. XXXIV, MAY, 1908. No. 5.
AMEEICAN SOCIETY OF CIVIL ENGINEERS
INSTITUTED 1852
PAPERS AND DISCUSSIONS
This Society is not responsible, as a body, for the facts anil opinions advanced
in any of its publications.
THE ELECTRIFICATION OF THE SUBURBAN ZONE
OF THE
NEW YORK CENTRAL AND HUDSON RIVER RAIL-
ROAD IN THE VICINITY OF NP:W YORK CITY.
Discussion.*
By Messrs, Edwin B. Katte, W. S. Murray, George A. Harwood,
W. B. Potter, Frank J. Sprague, Henry G. Stott, and
W, J. WlLGUS,
Mr. Katte. Edwin B. KATTE,t EsQ,— Mr. Wilgiis lias covered the subject so
completely that it does not seem possible to add much of general in-
terest; however, some of the details of the work already described will
perhaps be of value to those interested in a further consideration of
this electrical installation.
Storage Batteries. — Mr. Wilgus has explained that storage batteries
v/ere installed as an insurance against interruption to the train service;
this value was strikingly illustrated a few months ago, when, during
the most severe wind storm in this locality for many years, several
telegraph poles, which were on a high bank above the aerial trans-
mission lines, were blown down, and one pole, with its numerous tele-
graph wires, hung suspended on the 11 000-volt aerial transmission
lines. The effect was to open instantly the circuit breakers in the
power-station, and the safety devices in the sub-stations automatically
* Continued from April, 1908, Proceedings.
t Electrical Eaafiusei', New York Central and Hmlson River Railroad.
KATTE ON
ELECTRIFICATION OF SUBURBAN ZONE
OF N. Y. C. d. H. R. R. R.
Ko'^^ ^ ''W |2©«-= "l;^. P^f= *:afl ri^f' . ,K„, . ^«™. .
GENERAL PLAN
MAIN STEAM PIPING
POWER STATION
^f^.^rvr
♦
Foldout
Here
♦ ♦
♦
3AN ZONE
R.
Detiter Line I
qIuitds U ih
Center,
Line
' ZIolumns t
Center
Line
/^Columns S
H
Center
Line
Columns/?'
Center
Line
Columns^
Q II
I C^Lirie
Coluni!!
sa
Papors.] DTSCURSrON : ELECTRTFTCATTON OF N. Y. C. & TT. R. R. R.
48.'
disconnected from the load every rotary converter on the system. The Mr. Katte.
batteries were "floating" on the bus-bars, and immediately took up
the train load, and there was no interruption to service. The load
despatcher, knowing that the batteries would carry the load for a
sufficient time, was able, in an orderly manner, to locate the cause of
the trouble and then direct the various operators in charge of the
several sub-stations how to start up and tlirow in their rotaries and
pick up the load.
CURVES SHOWING DIVISION OF LOAD BETWEEN ROTARIES AND BATTERY.
TWO 1500 K.W. ROTARIES RUNNING.
BATTERY HAS 67 TYPE "R" PLATES, AND IS EQUIPPED WITH CARBON REGULATOR.
READINGS TAKEN AT INTERVALS OF 5 SECONDS.
SUBSTATION No. 2. AUG. 7, 1907.
outp
8000
Rotaries
1
7000
A
6000
/
\
Amperes
\
\.
1
f\
\
1
A
\
K
h
..1
A.
\
^
I
\
l\
1
Y/
s
:h
v^
-^'
1
V
^
vy
T
I"
T
A^
V
/>;»*>
M
V
\
\
\
V\
J
1
\
/
\
f
i ,
/
V
(
i
M
r^
J
M
i
¥
J
V
I
/
I
4
V
5.;io
32
33
34
5.35 36
Time
Fia. S.
37
38
38
5.40
Another reason mentioned by Mr. Wilgus for installing storage
batteries was to relieve the rotary converters and generators from the
sudden fluctuation of load due to the starting, stopping and passing of
heavy trains. That this has been eifectually accomplished will be
apparent from the diagram. Fig. 8, taken from actual readings at one
of the sub-stations, the heavy line representing the output of the sub-
station and the fine line indicating the load on the rotaries, the heavy
fluctuations having been taken up by the battery. The readings were
taken at 5-sec. intervals for a period of 10 min.
♦
Foldout
Here
♦ ♦
♦
ONE
1
Q
J
±'
rovided in sround
I f auxiliary ground
\1 asjnaiam bus.
TATION
NECTIONS.
Papers.] DISCUSSION : ELECTRIFICATION OF N. Y. C. & II. R. B..*R. 487
Mr. Katte.
I
w-
'ff. k'
♦
Foldout
Here
♦ ♦
♦
M
Papers.] DISCUSSION : KLKCTRIFICATION OF N. Y. C. & IT. R. R. R. 489
the nearest sub-station, and the entire third-rail system is paralleled by Mr. Katte.
auxiliary direct-current cables; this permits cutting out all third-rails
in a given section, and feeding around through the auxiliary cables to
adjoining sections for the operation of trains on either side of the dead
section. The diagram of positive feeders, Plate LXI, shows the various
connections to the third-rails and the auxiliary cables. Opposite each
sub-station, except the end ones, there is an isolated section of third-
rail sufficiently long to take the longest multiple-unit trains. The pur-
pose of this isolated section is to prevent a train bridging from a live
rail to a dead third-rail section, on which section there may have been
an accident, or on which men may be working, and further, to prevent
bridging, two sections of third-rail in which, because of their being
fed by different sub-stations, there might be a difference of potential
and thus cause the blowing of the motor fuses in the train.
Precautionary Devices. — Among the devices to ensure safety to
the system may be mentioned the indicating wire which has been woven
into the protecting braiding of the direct-current cables along the Park
Avenue Viaduct and through the Park Avenue Tunnel. The function
of this wire is to trip the circuit breakers and notify the sub-station
attendants by the ringing of a gong should a short circuit occur of
sufficient severity to cause burning or injury to the cable, but not
involving a quantity of current which woidd open the circuit breakers
on an over-load. The need of this device was demonstrated last year
on the Park Avenue Viaduct when a defective joint in a direct-current
cable failed, and, because of the disobedience of an attendant to follow
an order, all the switches to clear the short circuit were not promptly
opened. The burning continued for some time because the quantity
of current flowing was not of sufficient volume to open the over-load
circuit breakers, which, necessarily, have to be set to carry large quan-
tities of current for the regular handling of heavy trains.
A safety device installed in the Park Avemje Tunnel consists of a
cord, running parallel to all tracks, and connecting with signal alarm
boxes. If for any reason it becomes necessary to cut off current
quickly from any third-rails, a pull on the safety cord will open the
circuit breakers feeding that section of third-rail, and at the same
time will notify the attendant at the sub-station that the third-rail
has been cut out.
W. S. Murray, Esq.* — The thanks of the railway engineering Mr. Murray,
fraternity are due to Mr. Wilgus for this paper.
The author's theme is broad, and in the accomplislnnent of the
results severally cited, the speaker joins in the general assent regard-
ing the marked successes which rightfully have been obtained in this
stupendous work.
Only about half a page of this paper is devoted to conclusions with -
* Electrical Engineer, New Yorlf, New Haven, and Hartford Railroad.
W^'
V^ I
♦
Foldout
Here
♦ ♦
♦
h
Second Floor
Basement
Wf^^T,^
,1«M
Papers.] DISCUSSION : ELECTltlFICATION OF N. Y. C. & li. R. R. R. 491
which diagrammatic power connections were shown fundamentally in Mr. Murray,
principle, as adopted to-day, together with practical data, in the form
of traction, speed, power-factor, and efficiency curves. It seems to the
speaker that the State of New York would probably have been satis-
fied if the full time allowed had been taken, and, instead of being one
year ahead in operation, thought had been devoted to the single-phase
proposition. If, at the expiration of this year, the author did not
believe the art had been sufficiently advanced for its adoption, the
speaker believes that his first reason would not have existed.
(2). — Restricted clearances, which forbade the use of the overhead
conductors : There is a zone in which this matter has been handled.
Where the author can point to one restricted clearance on his line,
the speaker can point to five on the New Haven road, and does not
doubt but that the overhead obstacle clearance on the New Haven will
be found to be closer to the rails. The answer to this can be antici-
pated : — the overpowering argument — how would the Park Avenue
Tunnel be electrified? How have the Simplon Timnel, the Sarnia
Tunnel and other tunnels bee'n electrified? All these have restricted
clearances, and yet there is nothing mystifying or difficult about the
installation of overhead conductors under clearances of this character.
In short, unless the clearances in parts of the New York Central
electrification zone, other than those over which the New York, New
Haven and Hartford trains operate, are of a character strangely dif-
ferent, the speaker would undertake to install the overhead type of
construction,
(3). — The legal obstacles to the use of overhead trolley wires carry-
ing high voltages within the limits of the City of New York: Even
before that organization known as the Gas, Water, and Electric Light
Commission was dissolved by the bill introduced and adopted under
the present administration, Mr. Wilgus elected to erect his overheail
conductors within the limits of the City of New York, and chose for
their location, not points over the part of the railroad company's
right of way, where their traffic is most dense, but at its edges, and
there his transmission lines are carrying 11 000 volts. Why, therefore,
if these voltages can be assimilated by the City of New York on the
edges of the right of way, can they not be tolerated toward the center
of that strip of land, which will place them farther from the public ?
The speaker ventures the assertion that now that the State of New
York controls its public service corporations by a Public Utilities
Commission, it will confirm Mr. Wilgus' action in placing these high-
tension wires on the New York Central Company's right of way, even
if he has elected to place them as near as possible to the public. In
connection, also, with the question of high voltage, this discussion
would not be complete without a reference to such towns as Windsor,
Out., Hanover, Pa., Colfax, Wash., Palouse, Wash., Connersville, Ind.,
Here
♦ ♦
♦
is
h
I
=,-1
t(l
:3^-
Papers.] DISCUSSION : KLECTRIFICATION 01'' iN. Y. C. & H. R. R. R.
493
ti(jns to its competitor's one. In spite of this, however, the inherent Mr. Murray,
law which requires that a machine, in order to be a good alternating-
current motor must necessarily be a good direct-current motor, has
been demonstrated in the records of the electric meters installed on
the New Haven locomotives for measuring the power while handling
the trains in the New York Central zone.
While tests could be conducted to show that either locomotive would
cjirry a given trailing load from the Grand Central Station to Wood-
lawn at the expenditvire of a less number of kilowatt-hours than the
other, such tests, unless conducted over a long interval, are valueless,
bvit Table 5 is the record for the month of February, showing the
energy consumption upon which the New Haven road is billed by the
New York Central Company, and is of value.
TABLE 5. — Total Kilowatt Consumption for Eleutric-Tuain Serv-
ice IN New York Central Zone.
Date.
February.
Direct
current,
iiours.
Direct
current,
miieb.
Total
tonnage.
Pa.ssengers
carried.
Number of
commercial
trains.
1
7110
564
11 384
7 961
40
2
4 650
420
7 148
5 196
21
3
6 880
552
11 116
9 190
39
4
7 010
540
11 388
7 708
38
5
8110
600
11666
,0401
44
6
7 490
564
13 205
8 639
42
7
7 750
600
U 687
9 611
44
8
8 860
660
14 114
11 270
46
9
4 150
396
7 295
5 131
21
10
5 690
458
9 231
7 515
35
11
5 360
420
8 314
6.578
33
12
6 430
588
13 018
7 415
43
13
7 900
648
13 361
10 .536
46
14
8 390
624
13 757
10 973
46
1.5
9 030
736
15 932
12 0.55
50
16
4 730
432
7 778
5 628
21
17
8 760
660
9 008
11 790
46
18
8 530
624
13 463
11 112
45
10
8 730
696
14 285
10 4.32
48
20
7 890
624
13 851
l(t 9.57
46
21
8 6.50
673
14 607
12 098
48
22
8 910
784
15 494
8 094
49
23
4 230
3()0
6 607
4 575
18
24
8 610
673
14 561
1 1 833
47
25
7 840
660
14 412
n 448
48
26
7 610
636
14 413
10 860
48
27
9 310
660
14 547
1 1 732
48
28
8 780
684
14 629
11 844
48
29
8 580
756
16 333
12 887
50
215 860
17 388
354 399
273 469
1 197
Average watt-hours per ton-mile = 41.8.
The speaker does not wish to enter here upon a theoretical discus-
sion of the rate of energy required to discharge a given schedule, but
wishes to point out the fact, well known by all electrical traction en-
m:^'\;'t::^
':^':4-: l: '.
f*^/!{ff:;-ff^f''ii'H|:'?U';':f;;if'f^;^
♦
Foldout
Here
♦ ♦
♦
m
1-
PaiuMS.J DiscUlSSiUN : ELKCTUliaCATION OF N. Y. C. & Jl. K'. It. H. 495
Tfaven alteniating-current-flirect-enrrent locomotive cost less than the Mr. Murray.
New York Central locomotive, notwithstanding the continnous capaci-
ties of the two machines are very nearly the same), the cost per mile
of electrification is in the ratio of 5 to 1. It is true that much of this
cost is made up of land, which was necessary for sub-stations, and
thousands of pounds of copper, but it should be remembered, in com-
paring it with the single-phase system, that in the latter these require-
ments are practically dispensed with. Sub-stations are reduced to
zero, and copper to a minimiim, and so the speaker thinks that in
mentioning this increase of power required to operate New Ilaven
locomotives, this attendant factor of five times the fixed charge should
be, at least, mentioned.
As much in importance, after considering the fixed charge of an
installation, is the cost of operation. Again, in virtue of the necessity
of the close co-operation of the two companies, in so far as the audit-
ing of accounts is concerned, figures appertaining to this interesting
subject necessarily passed through the hands of the speaker. It was
found that for 12 miles of four-track road there is a charge, for main-
tenance and operation, of five times the amount the New Ilaven road
pays to maintain and operate 21 miles. Although he has the exact
figure^s covering the disbursements necessary to the installation of
each form of distributing system, he has not felt justified in present-
ing these figures at this time. However, the ratios mentioned serve
the same purpose.
In conclusion it should be stated that the principal object of the
New Ilaven engineers has been simplicity. True, the use of the direct
current on the rails over which their locomotive had to operate was a
sort of kink in the wire, but they were not responsible for this, nor
has it carried any especial terror to their hearts, and had it not been
superimposed upon them, like the other parts of the system, the con-
trol in their locomotives would have been simplicity itself.
Mr. Wilgus has spoken of the violent fluctuations of the load on the
power-station and sub-stations, which are corrected by the use of storage
batteries. On the twenty-one miles of the New Haven road there
are no storage batteries, but, due to the high efficiency of transmission
and the prompt regulation of the generators at the power-station for
fluctuating loads, even at the western terminus, the most distant from
the power-station, the voltage seems to be practically as stiff as at
Cos Cob.
In yards, a light but strong cross-catenary form of construction is
readily applicable to this branch of electrification. The question of
dodging the third-rail no longer confronts the yard hand. There is
8 ft. of good air between the trolley wire and the tops of the freight
cars, thus providing clearance for the tallest man.
The speaker's argument has been based upon official data for the
♦
Foldout
Here
♦ ♦
♦
\H ZONE
'il
Papers.] dI.SCIT.SSION : ELECTKIKICATION OF N. Y. C. & H. K. R. R.
497
42ud St.
Mr. Harvvood.
- 3J
SECTION OF TRAIN SHED
AT ARCH NO. 10 - LOOKING SOUTH
♦
Foldout
Here
♦ ♦
♦
I
te v^^
G '
Papers.] DISCUSSION : ELECTRIFICATION OF N, Y. C. & H. R. R. R.
499
tljrongh the openings, the canopy construction following the movement Mr. Harwood.
of the traveler may be seen.
Fig. 12 shows the details of the temporary canopies. These are of
Ihe butterfly type, with a large overhang so as to provide maximum
protection.
The preparation of the detailed plans and the execution of the work
are under the charge of Mr. J. L. Hoist, Engineer of Structures.
DETAILS OF TEMPORARY CANOPIES,
GRAND CENTRAL STATION.
ut 4Itb St.
Section U-a
Fig. 13.
W. B. PoTTKR, M. Am. Soc. C. E. — This paper presents a compari- Mr. Potter,
sen of steam and electric operation in a very interesting and compre-
hensive form, and the speaker wishes to express his appreciation of the
valuable information given therein.
Reliability of service under electric operation is very properly re-
garded as a matter of first consideration. The installation of dupli-
cate power-houses and storage batteries, considered as an insuranca
Papers.] dTSCUSSTON : ELECTRIFICATION OF N. Y. C. & II. R. R. R. 501
quently indicate, show that there is a saving in favor of electricity Mr. Potter.
vphich will be found in reduced incidental expenses rather than in
the cost of direct operation.
There are some points in Mr. Murray's discussion with which the
speaker does not agree. The reliability, initial cost, and cost of opera-
tion, for the service between New York and Stamford, are all in favor
of direct current. This will be more especially true if multiple-unit
trains are operated in the local service. The complexity incident to
alternating-current and direct-current operation, and the relative cost,
as influenced by the number of trains under the particular conditions
in this instance, introduce features unfavorable to the alternating-
current system. The speaker, however, does not wish to be misunder-
stood, or to be regarded as not favoring the alternating-current system
under conditions more favorable to its application. He thoroughly
endorses what Mr. Henderson has said in regard to the importance of
studying the local conditions as atfecting the general scheme of elec-
trification, but believes that greater density of traffic usually insures
a greater uniformity of load, so that the common expression, "density
of traffic is favorable to electrification," is usually true.
Mr. Wilgus and his associates are to be congratulated on their
success, and for the satisfactory service which they have rendered the
public in the work they have done.
Frank J. Sprague, M. Am. Roc. C. E. — The Society is to be con- Mr. Sprague.
gratulated, and Mr. Wilgus complimented, upon the presentation of
one of the clearest expositions of the results obtained in an electrical
equipment of great magnitude, under particularly trying steam-rail-
road conditions. It is a concise and definite statement of facts, where
real comparisons are possible, made in plain terms, and within the
reach of such railroad men as are not trained electrical technicians.
With the view taken by Mr. Henderson, the speaker wishes to ex-
press cordial agreement, as it is one which he has spent a number of
years in voicing, namely, that the wisdom of the application of elec-
tricity to the equipment and operation of a steam railroad — and, it
may be added, the method of such application if adopted — is a problem
individual to the needs and conditions existing on that particular
road, and cannot be determined by any general statements of real or
fancied gains in fuel economy. Nor is it sufficient that economies, of
whatever nature, promise a fair interest on the new investment required,
for, if this were all, there would be no excuse for the adoption of
electricity, because the existing investment would have derived no ad-
vantage, and every railroad man knows that there are ways of invest-
ing money in railroad improvements M'hich will result in much more
than a return sufficient to pay interest on the new capital — a fact not
without vital influence at a time when money seeks the seclusion of
the tin box and the stocking.
502 DISCUSSION : electrification of n. y. c. & IT. K. i;. i;. I l''»p"'^-
Mr. Sprague. ^t the present moment the field of electric application is more ap-
parent where trunk-line terminals and suburban service are concerned,
for here there are certain favorable conditions conducing to success,
such as density of traffic, fair load factor, and reasonably uniform traffic
conditions and train movements, vphile public sentiment favors the
abolitif)n of smoke and steam, and suburban populations demand more
rapid and freqiient train service.
Tn addition, there are mountain roads where onerous conditions
are imposed by local difficulties or connecting divisions, and these, in
spite of an irregular and widely varying traffic, may advantageously
consider electrical ojjeration. Tn both classes, however, the key-note
is capacity, with an eventual gain in unit and system economy.
Up to the present, the most conspicuous example of terminal and
suburban equipment is that so well described by the author, and with
regard to this Mr. Murray states his belief that a mistake has been
made, and that if the decision as to the most suitable equipment were
to be made now "a majority of the best informed electrical engineers
of America would to-day cast tlicir ballol in fnvor of single-i)lias(> ek^c-
trification."
Just here, and without expressing any opinion as to the merits of
that system — and there are many valuable arguments in its favor for
some classes of roads — the speaker must record his judgment that
this statement is entirely wide of i)robability and fact, and, basing his
conclusion upon the comparative results shown by the competitive sys-
tems now in operation on the New York Central and New Haven roads,
must record his conviction that if confronted to-day with like actual
conditions, not only would the majority — and he trusts all — of the
members of the New York Central Electrical Commission, but any
other competent board representing sound electrical engineering and
conservative railroad practice, make the same general decision as
originally made, modified possibly in degree of potential adopted and
some details of eqiiipment. Furthermore, it is quite possible that the
somewhat extraordinary degree of insurance of operation would not
now le decidc^d ujjou, but it must be remembered that, to a certain ex-
tent, much of wliiif was adopted was based ujion tlie idea of ])roviding
insurance at first and utilizing cai^acuty later.
In the development of the equipment for the New York Central,
there were some matters of greater or less novelty concerning which
some risk had to be taken, and among these there may be mentioned
the vertical turbines, the particular type of locomotive, and the under-
contact protected third-rail. There were ample criticisms and many
predictions of failures as to nil l\\vvo features, and I'rcun ninny <iunrt('i's;
but it is with some degr(>e of complacency that the speaker recalls his
own connection with this development, and the practical results at-
Icuding lb(! adoption of these ]inrticular features.
Pnpprs.] DTSCURSION : KLEOTltlFIOATTON OF N. Y. C. & TF. If. 1?. R. 503
There have been no "frightful accidents" with the turbines, and Mr Spiague.
the locomotive has shown a capacity and reliability simply amaz-
ing, for it has been called upon for a hauling capacity of nearly
100% in excess of its guaranty. On some recent trials it has
run more than 650 miles on consecutive days, stopping and start-
ing within 6-milo limits, and has made nearly 700 miles within
24 hours nnder these conditions. The machines are not perfect,
iiud, undoubtedly, some minor changes will ultimately lie adopted, bnt
it is instructive to note that, in the year and a half of operation, the
makers have spent probably not more than $4 000 in changes on the
entire equipment, and not one dollar of this has had to do with the
motors or their design. In that period the electric service has increased
up to a present maximum of about 300 movements a day by electric
locomotive and by multiple-unit train, and in all that time there have
lieen recorded but two electric locomotive failures on the track, where
tlie locomotive could not pull itself. Its single-phase competitor, in
one-third of that time, on 13 miles of road, and with a maximum of
GO train movements, has a record of at least 40 failures. If it had
not been for the New York Central's electric locomotives, or multii)lo-
unit trains, the effect of these failures would have been more pro-
nounced.
ITndoubtedly, the causes of some of these failures will be removed,
and a better record will be shown by the single-phase machines, but it
will be some time before there can be any final comparison between
these two systems. Two facts, however, even now stare one in the face :
The first is that the speaker's predictions (made some time ago) as to
the relative capacity, have been borne out in practice, for while single
direct-current locomotives have thus far pulled any load which has
lieen put behind them, it is customary to use two single-phase loco-
motives whenever the trailing load exceeds six suburban cars or six
cars of moderate weight. The second is that, in spite of the adoption
of locomotive operation only, operative demands will eventually make
necessary the use of multiple-unit trains for all suburban service out
of great terminals; and, when this latter is attempted under the con-
ditions which exist, the net residt of the operation of such trains on
combined direct and single-phase divisions will be absolutely dis-
appointing when compared with the operation of multiple-unit trains
on the direct-current system alone.
A third feature, which was a maltcr of some concern, was the
under-contact third-rail, in the dev(>lopment of which the speaker had
the pleasure of co-operating with Mr. Wilgus. It was possibly some-
what more costly to install this third-rail, under existing conditions,
and it has been more or less costly in its up-keep. The speaker has
made an effort to secure some comparative costs of maintenance of
this rail, l>oth on the New York Tentral and in other localities. The
504 discussion: ELECTRIFICATION OF N. Y. C. &H. U. R. R. [Papers.
Mr. Sprague. Iccal conditions on the New York Central are unusual in character,
and the accounts are complicated more or less by the costs of new con-
struction, so that they cannot at the present time be given with any
degree of reliability. One special difficulty has developed, to which at-
tention should be called, which, however, is the fault of a collateral
feature of the general equipment. A third-rail, whether of the top- or
bottom-contact type, and especially where there is much special work,
will operate most satisfactorily when the contact shoe is maintained
within reasonable limits of operation. Unfortunately, the contact
shoes on the New York Central locomotives are not carried, as they
should be, upon the frames moving with the pilot trucks, but upon the
superstructure above the equalizing springs. The result is a horizontal
and vertical movement probably fully three times as great as would
exist with another possible method of mounting. This has been the
cause of some trouble at side inclines and elsewhere.
The speaker has reports of very different character from some other
roads, where this particular difficulty does not exist, and where the
operation is strictly normal, and comparable with other systems of
working conductors. On the West Shore Railroad, operating for the
8 months from July 1st, 1907, to February 29th, 1908, with a monthly
average of 77 204 miles, the official reports give the following averages
per month during this period :
Material $163.26
Labor for repairs 18.32
Labor for inspection 297.71
Total $479.29
As this equipment covers 105 miles of track, the total cost charge-
able to third-rail is $4.56 per month per mile.
The Philadelphia Rapid Transit Company has 12 miles of this
rail, and the chief engineer reports an actual car mileage of 1 500 000
miles for 1907, and states that:
"The total cost of up4veep during 1907 has been practically noth-
ing, as but two insulators required changing, and these were probably
cracked when installed. The covering will probably require painting
during 1908."
Of course, in time there will be opportunity to make direct com-
parison between the cost of up-keep of this type of third-rail and
various types of overhead construction, and, concerning the latter, the
spea-ker is inclined to think there will be some developments, but it is
interesting to note one comparison, tliat of the maintenance of a top-
contact unprotected third-rail and an overhead trolley of the usual
class on one of the most important electrical railroads in America,
Papers.] DISCUSSION : ELECTRIFICATION OF N. Y. C. & H. E. R. R. 505
operating nearly 128 miles of third-rail and nearly 20 miles of trolley Mr. Sprague.
wire. In this particular instance, recent reports show a ratio of 3.8
in favor of the third-rail.
On the subject of the adoption of systems, and as illustrating how
unsafe it is to predict what will be done in any particular instance,
it is but proper to call attention to the fact that the electrical engi-
neer of the Government railways in Belgium — they are all owned by
the State — came to America a few months ago, from close proximity
to alternating-current developments, and with some prejudice in favor
of them. He had ample facilities for inspecting equipments in
America, and on his return he reported to his government squarely
in favor of using direct current and third-rail for the first equipment
put in by the Belgian Government, and orders for a part of this
equipment were recently supplied from America.
The speaker has also recently received from one of the foremost
electrical engineers in England, Mr. Parshall, who has been identified
with a large amount of electrical work there, is very familiar with
conditions abroad, and follows developments there very closely, a letter
which reads as follows:
"You have heard a great deal of alternating current development
on this side of the water ; I beg to assure you that they are all interest-
ing from a laboratory standpoint, not one would meet the conditions of
American practice; they are instructive as telling what not to do rather
than what to do."
The speaker does not wish to prejudice the cause of the single-
pliase system. He seeks but the truth with regard to any equipment;
there are cases in which he believes that that particular system may
be used with advantage, but he holds unalterably to the view that the
very best interests of electric railway development require every possi-
ble advance in either system, and that a hide-bound adherence to any
one cannot but result in adverse developments.
Henry G. Stott, Esq.* — Mr. Wilgus gives certain reasons f or Mr. Stott.
duplicating power-stations and transmission lines, but a stage in the
art has been reached where there is no longer any very strong argu-
ment for duplicating power-stations. The speaker's experience, cover-
ing quite a number of years with power-plants, is that the greatcsr
danger now is not from the apparatus, but from the men who operate
it. Take, for example, the two largest power-stations in New York
City, each of which is giving out about 75 000 h-p., morning and night.
In the past six years of operation the speaker can recall only two shut-
downs which were due to the power-plant, and these were of very short
duration, from 10 to a maximum of 20 min. It is obvious that the
duplicate power-plant would not help such a situation, because, unless
* President, American Institute of Electrical Engineers.
50G DISCUSSION : electrification of N. Y. C. & II. R. R. R. [Papers.
Mr. stott- all the boilers were fired up and the units were turning over con-
tinuously, at least 40 min. would be required to get them into service,
by which time the power-station would be in operation.
In regard to the transmission lines, the power-stations necessarily
must all be connected to a common system, otherwise, the copper in-
stalled would be wasted, and the rotaries in the sub-stations would have
to be started over again, unless they were connected.
A few days ago there was a shut-down on the Manhattan system.
The trouble was in the transmission lines, and was caused by one of
the steam heating mains in the city destroying the insulation. If there
had been a dozen power-houses, instead of two, there would have been
the same trouble ; and it can safely be said that it is a great deal better
now to "put all our eggs in one basket and watch that basket, than to
put them into separate baskets," in view of the fact that the Miman
element is now the most dangerous one.
The operating and fixed charges are certainly less for one plant
than for two. In working out power costs it is just as necessary to
take into consideration the fixed charges as the operating costs. Th-
fixed charges in many cases are greater than the actual operating and
maintenance cost. It is a very poor plant to-day which cannot operate
at less than 0.7 cent per kw-hr., that is, for operating and maintenance
charges only. Fixed charges on a load factor of 50%, which is about
the best load factor that railroads can expect, would be at least equal
to that. Now, if the load factor is less, naturally the operating charges
become of less importance, and the fixed charges of greater importance.
In the plants described in the paper there is apparently going to be
100% spare apparatus. The safe over-load capacity of modern
generators and turbines is usually given at 50% above rating, so that,
even if the whole apparatus is being used, there is always a reserve
capacity of 50%, making in this case a reserve of 200% ; but, in con-
sidering peak loads, such as all railroads get during the morning and
evening, due to the movement of suburban trains, a very much smaller
load factor must be considered. In this case it is most important to
keep down the fixed charges, which, under these conditions, may be-
come three or four times as great as the operating charges.
Mr. Wiigiis. Wirjj.vM J. WiLCrs, M. Am. Soc. C. E. (by letter). — As anticipated,
this discussion has brouglit out many points which will go far toward
solving the modern problem of electrifying steam railways.
Reference is made by Mr. Henderson, Mr. Gibbs, and Mr. Francis
to the large collateral expenditures that have a bearing on the com-
parative cost of operation by steam and electricity; but one should not
lose sight of the fact that such contingent expenses, in the installation
under discussion, are a necessity entirely apart from the question of
electrification. For instance, the enlargement of the Grand Central
Terminal, fonv-trnr-king, elimination of grade crossings, and similar
Papers.] DISCUSSION : ELEGTRIFICATIOM OE N. Y. C. & 11. K. li. R. 507
items, are required for liandliiig a growing traffic properly. Indeed, Mr. vvilgus.
it is true that most of these improvements are only possible with a
change of motive power; but that is an added argument in favor of
electricity. In other words, if there had not been the desire and neces-
sity of radically enlarging the capacity of the railroad, it would have
been possible to have made the change from steam to electricity, with
a resultant material but insufficient increase of capacity, without in-
curring any expense for other improvements.
On the other hand, there are many places where the installation of
electricity, with its superior operating advantages, will not only save
in annual cost of operation, but, in addition, obviate the undertaking
of expensive improvements that with steam would be necessary for in-
creasing the capacity of the railroad.
Therefore, while it is proper to concede that the use of electricity
on the New York Central has invited the undertaking of other large
expenditures for greatly increasing the earning power of the railroad,
it is not just, in comparing the cost of steam and electric operation, to
charge against the latter fixed charges other than those made necessary
by the change of motive power alone.
The proof of the wisdom of making these collateral improvements
must rest on later developments of traffic, when the entire scheme has
been completed.
Mr. Henderson's analysis of the relation of average to "peak" traffic
is very interesting, and is borne out by an application of his reason-
ing to the New Haven Company's installation, had direct current been
used between Woodlawn and Stamford. As shown below, the annual
propulsion current requirements at the Cos Cob power-station bus-bars
is, say, 18 500 000 kw-hr. The power-station installation for propulsion
current is assumed to be 13 500 kw-hr. for direct-current operation.
This would make the ratio of power installation to average train re-
quirements 6.4, the cost of electric operation being slightly lower than
by steam. Probably a ratio of 6 would represent an equality of cost
of operation by steam and electricity under New York Central and
New Haven conditions, which would agree closely with Mr. Henderson's
conclusions, if he had omitted the portion of the power-station in-
stallation not intended for propulsion purposes. Of course, on both
roads, increase of passenger traffic and the later handling of freight
traffic, labor-saving machines, and yard switching by electricity, will
raise the average load and produce still better results.
As intimated by Mr. Gibbs, it is perhaps too early to forecast with
positiveness the saving of electric operation over steam in the various
installations made to date, but the many misstatements to the contrary
that have appeared from time to time in technical discussions cer-
tainly point to the wisdom of throwing some light on the subject before
the means disappear of making true comparisons under like condi-
508 DISCUSSION : electrification of N. Y. C. & H. R. R. R. [Papers.
Mr. Wilgus. tions. Regarding locomotive repairs, there is no doubt that changing
of types and details will ensue, and the cost will be chargeable to re-
pairs; but such changes are also constantly occurring in steam prac-
tice. The obsolete machine is simply relegated to a less exacting serv-
ice. It is true that duplicate facilities must be maintained for han-
dling the motive power at interchange terminals; but there will soon be
no occasion for expensive facilities for handling suburban steam loco-
motives, as their electric substitutes will require small inspection sheds
only, and the relatively small steam locomotive plants for through,
trains will be removed from costly New York City real estate to out-
lying cheap lands. As Mr. Gibbs states, there is difficulty, on electri-
fied steam roads, in obtaining the desired full mileage from electric
rolling stock. However, where the traffic is dense, and reasonable at-
tention is paid to this feature by the operating department, it is be-
lieved that reliance may be placed on the results outlined in the paper.
Mr. Waitt's reference to European practice, based on his personal
investigations abroad, is both interesting and instructive. There is
the frequent tendency among American engineers to urge the adoption
of foreign practice unsuited to American conditions.
The remarks of Mr. Lewis and Mr. Francis point to the desirability
of a future paper dealing with the New York Central improvements
from the "static" standpoint, but this, of course, cannot be done until
the work has more nearly approached completion. Mr. Katte and Mr.
Harwood briefly touch on some of the details.
Mr. Brinckerhoffs experience with elevated railway service gives
much weight to his' comparison of the operating costs and efficiency of
steam and electric motive power, especially the item of maintenance,
about which some question has been raised.
As remarked by Mr. Sprague, if the question of electrification is to
be approached from the standpoint of a fair return on the new invest-
ment required, something beyond the ordinary rate of interest must be
offered to the investor. Wliile the electrification of the New York
Central was undertaken for reasons apart from possible economies of
operation, as will be shown below, the prospective savings are such as
to promise a return of not only the ordinary rate of interest on the
capital invested, but also an additional amount for the stockholders,
the aggregate of these two items being estimated at about 9% on the
additional capital required for electrification. The cost of maintain-
ing the third-rail in the initial zone is comparatively high, not for the
reasons given by Mr. Sprague, but because of the many minor adjust-
ments, alterations of tracks, and close inspection, all of which are in-
cident to the newness of the installation.
Both Mr. Stott and Mr. Potter express the belief that reliable serv-
ice may be amply insured without the precaution of a second generat-
ing station. Referring to the reasons given for duplicate power-sta-
tions,* it will be noted that two power-stations were decided upon:
* Proceedings, Am. Soc. C. E., tor February, 1908, p. 72.
Papers.] DISCUSSION : ELECTRIFICATION OE N. Y. C. & H. R. R. R. 509 "
"each with sufficient capacity, utilizing its spare luiit, and working Mr. Wiigus.
'overload/ to carry the entire demand of the service at the rush hours,
should the other fail."
Had one power-station been decided upon, an additional unit would
have been required for spare purposes, making 25 000 kw-hr. instead
of 20 000 kw-hr., from which it will be noted that instead of 200%
spare apparatus in the two power-stations, there is but 60%, including
the 50% over-load capacity of the generators. Therefore the question
of the wisdom of installing duplicate power-stations hinges upon the
necessity of having this 60% excess capacity at the initial stages of
the service, and the additional expense attendant upon the operation
of two power-stations instead of one. The Electric Traction Commis-
sion considered these features thoroughly, and concluded that the com-
pany was justified in this additional expense for the reason that the
geographical location of the two divisions, with their possible future
extensions to the north, was such as to make unwise the adoption of
but one station for both, located at a remote point and subject to such
injury to itself or the connecting transmission lines as to make possi-
ble a long-continued interruption of train service. For instance, should
a single power-station or its connecting transmission line suffer serious
injury from rioters, strikers, accidents on adjoining property, or any
other contingency sufficiently serious to place the power-station out of
commission for a long-continued period, as was experienced on one of •
the English railroads which was electrified some years ago, a return
to the use of steam locomotives would be imperative. The contemplated
future electrification of freight service within the electric zone, includ-
ing the terminals on the west side of Manhattan Island, the electrifica-
tion of all or a portion of the Putnam Division, and the utilization of
company current for lighting, yard switching, labor-saving devices,
etc., promise a reasonably early use for the excess capacity of the
power-stations sufficient to justify its expense for these insurance pur-
poses during the early stages of electric operation. The location of the
two stations, in better relation to the load centers than would be possi-
ble with one station, offers a saving of transmission losses that tends
to compensate for the extra cost of operating two power-stations over
one. That the company anticipates early need for the excess capacity
is shown by its recent decision not to accept a proposition for its pur-
chase or lease by outside commercial interests.
It will be interesting to note here that the cost of the power-stations
was very low — less than $90 per kilowatt of capacity.
In the paper there was no intention of raising any issue with the
representatives of the New Haven Company because that company
saw fit to select a form of electrification difi^erent from that adopted
by the New York Central. The paragraph first quoted by Mr, Murray
had reference to the proven wisdom of adherence to the chosen type of
510 DISCUSSION : electrification or N. Y. C. & H. R. R. R. [Papers.
Mr. WiiKus. direct-current equipment, despite the urging by a manufacturing com-
pany upon the New York Central of the alternating-current-direct-
current apparatus; and in no manner reflects on the vise of the alter-
nating-current system, per se.
However, as Mr. Murray has broached not only the question of the
wisdom of the policy pursued by the New York Central, but also the
wisdom of his own company's adoption of the alternating-current sys-
tem north of Woodlawn, there is no recourse but to set forth the whole
matter in sufficient detail for the drawing of correct conclusions. This
is perhaps fortunate, for the present uncertainty in the minds of steam
railroad officers is injurious to the advancement of the art of transporta-
tion, and peculiarly hurtful to the legitimate growth of electrification,
whether by direct or alternating current.
There is really no quarrel between the alternating-current and di-
rect-current systems. Both have legitimate fields. It is no more
proper to compare them broadly than to contrast, say, a ''Pacific" type
passenger locomotive with a Mallet compound freight locomotive.
They must be viewed in relation to a known service, and the care de-
volving on the engineer is to see that they are not misplaced. Legal
restrictions, nature of traffic, mixture of steam and electric motive
power, population, clearances, and other special conditions, all have
bearings on the selection of the system of electrification best suited
to any particular locality. It is a cause for congratulation that there
is a choice of three systems, direct-current, alternating-current single-
phase, and alternating-current three-phase, rather than but one system
which would be unsuited to many localities seeking release from thp
limitations of steam.
The question, then, is whether or not either company has mis-
applied the system that it has adopted. The elements to be considered
are:
(1) Physical and legal restrictions,
(2) Operating requirements,
(3) Safety,
(4) Reliability,
(5) Cost.
(1) Physical and Legal Restrictions. — The law taking effect July
1st, 1903, requiring the abandonment of steam in Park Avenue south
of the Harlem River, within five years, gave an insufficient margin of
time for the making of radical experiments, which, if unsuccessful,
would cause delays alike distasteful to the public and the railroads.
The temper of the public^ atmospheric conditions in the Park Avenue
Tunnel, and the congested nature of the Grand Central Terminal
yard operations, were such as to dictate the utmost speed in effecting
the change, in the interests of safety and public comfort.
Papers.] DISCUSSION : ELECTRIFICATION OF N". Y. C. & H. R. R. R. 511
Of the two systems, direct current and alternating current, the Mr. Wilgus.
former offered apparatus of proven reliability and efficiency, whereas
the latter, at the time of the decision in the fall of 1903, was declared
by its warmest advocates to be unsuitable for meeting the onerous con-
ditions of the case. The state of the art was not sufficiently advanced
to warrant the use of a system still untried in heavy trunk-line serv-
ice; but, apart from this reason, there were others of even a more con-
vincing nature.
The four-track Park Avenue Tunnel, 2 miles in length, with a
head-room affording but 1 in. of clearance above the top of the rolling
stock, is confined between the city street pavements immediately over
the roof and the city sewers beneath. The overhead conductors and
contact devices on the equipment of the alternating-current system
would require at least 2 ft. 6 in. more head-room, obtainable only by
radical changes in city sewers, to obtain consent for which would be
very problematical; and the lowering of 8 miles of tracks in solid rock,
in a smoke-laden tunnel through which flows at nearly all hours of the
day a congested traffic of from four to five times the volume of the
New Haven Company's traffic north of Woodlawn. Even if feasible
and safe, the cost of doing this would be prohibitive. That such a
change of the tunnel is impracticable from the legal standpoint is well
shown by the fact that the public authorities stopped the company
from drilling and blasting for electric ducts in the side-walls of the
tunnel, during the few hours of the night when traffic conditions per-
mitted the prosecution of work of even that simple character; and pipe
ducts were substituted, hung from the tunnel walls. Then, too, the
required method of rebuilding the Grand Central yard in sections dur-
ing a period of many years, in conjunction with the construction of
lofty buildings over tracks carrying traffic, prohibited the use of exposed
overhead trolley wires alive with a current as dangerous as 11 000 volts.
That Mr. Murray can place these trunk-line conditions, in next to
the largest city in the world, in the same class with the totally different
and vastly less complicated problems on his own line, and at the
Sarnia and Simplon Tunnels, is strange. The repeated promises and
as frequent failures of Mr. Murray's company during the past year to
complete its change to electricity, with the resultant serious delay to
the Grand Central Terminal reconstruction, and annoyance to the
public in the Park Avenue Tunnel, are the most speaking commentaries
on the offer of Mr. Murray to undertake so blithely this task for others.
Apart from these physical objections to the overhead alternating-
current system, there were serious legal obstacles.
The four-track Park Avenue Viaduct north of the tunnel, li miles
long, was built under legislative enactment that prescribed the exact
design. To modify this materially by the erection of trolley wires and
supports would surely invite injunctions by abutting property owners,
512 DISCUSSION : electrification of N. Y. C. & H. R. R. R. [Papers.
Mr. wugus. and resultant indefinite delays and enormous damages. The previous
experience of the company with its neighbors in this thoroughfare,
.costing millions of dollars, taught a lesson that could not be disre-
garded.
The crowning legal obstacle was the objection of the city authori-
ties to any form of overhead wires carrying high voltages along and
over streets within the city limits. While the company has contended
that transmission lines in the outer and sparsely-settled sections of the
city, placed on the exterior edges of the right of way and passing far
above the surface of intersecting streets, were permissible and even
desirable, at least until the growth of population required a change to
ducts, it did not feel that it could be denied that trolley wires carrying
1] 000 volts immediately over and close to rolling stock and imme-
diately beneath public travel on intersecting street bridges, would be
sufficiently objectionable to invite ultimate adverse action by the pub-
lic authorities that would entail a complete abandonment of a system
costing the stockholders many million dollars.
With these absolute baiTiers to the use of high-voltage trolley wires,
the Xew York Central, apart from other reasons, could not do other-
wise than adopt the direct-current system, which in New York City
is feasible and legal. The New Haven line, lying in the open country,
did not have these obstacles, and adopted the alternating-current system.
(2) Operating Eequirements. — The constantly increasing traffic in
the congested Grand Central Terminal demanded a tj^pe of self-pro-
pelling electrical equipment that would minimize the number of
switching movements across the throat of the yard. Experience else-
where, also, had demonstrated the need of an elastic system of train
• operation, which, apart from the question of economies, would permit
quicker acceleration, a more frequent service, and the regulation of
the number of cars per train to the volume of traffic at different hours
of the day. All these objects could be obtained by the use of multiple-
unit cars, which, in the existing state of the art, seem best adapted to
direct current.
The New Haven Company, in adopting alternating-current opera-
tion, rejected the use of the multiple-unit system, whereas the New
York Central seized the opportunity to use it, with resultant imme-
diate benefits to its operating department. That Mr. Murray's com-
pany now realizes its mistake is shown by its recent design of an
alternating-current-direct-current multiple-unit train consisting of a
motor car on each end of a six- or eight-car train. The success of such
an arrangement is very questionable, from operating as well as elec-
trical standpoints, and at least one large manufacturing company has
declined to build it.
(3) Safety. — This item, referred to by Mr. ]\Iurray, should be con-
sidered in its twofold relation, to the employee and to the public, and
Papers.] DISCUSSION : ELECTRIFICATION OF N. Y. C. & H. R. R. R. 513
not to one alone. Both, naturally, deserve the very best judgment and Mr. Wilgus.
care in deciding upon the kind of distributing system to be used.
Experience has shown that the low-voltage third-rail, suitably pro-
tected, is not dangerous. During the period of a year and a half that
the working conductors have been energized in the congested initial
electric zone of the New York Central, not a fatality has occurred
either to employees or the public, primarily due to the third-rail or
transmission lines. Three instances have been due to trespassing on
the transmission line, another to a porter reaching beneath the third-
rail for a pack of cards, and one to a prior contributing cause.
On the other hand, up to the present time, the New Haven trolley-
wire system and transmission lines have apparently caused thirteen
fatalities, largely due to wires not being "beyond the reach of the
tallest man."
Carelessness, no doubt, is responsible for the majority of these un-
fcirtunate occurrences, but is it not a duty to select the system which
local conditions dictate as least dangerous to the negligent employee?
As to the public, the third-rail is entirely removed from neighbor-
ing thoroughfares, and the transmission lines in sparsely settled dis-
tricts, spanning far above intersecting streets, seem to have the ad-
vantage of safety, superior to that of 11 000-volt trolley wires passing
directly beneath street bridges of low clearance above the tracks and
within a few inches of the passers-by.
On the direct-current system, in case of accident, the passenger is
as well or better guarded from the third-rail by means of protecting
sheathing and circuit-breakers, as he is from knocked dovpn trolley
wires which may affect not one but all four tracks.
May it not be concluded that, as measured by both practice and
theory, the direct-current system, in the territory under discussion, is
preferable to the alternating-current system, from the standpoint of
safety, having in mind the local conditions?
(4) Eeliability. — This question is of first importance to a trunk-
line railroad. What has experience shown in the two systems under
discussion ?
During two representative months the delays per 1 000 locomotive-
miles between Woodlawn and the Grand Central Station, due to loco-
motive failures, were as follows:
New York Central direct-current locomotives. . 1.2 min.
Steam locomotives 2.
New Haven alternating-current locomotives . . . 12.4 "
It will be noted that the alternating-current locomotives in this
service caused eleven times as many train delays as the direct-current
machines, and six times as many as due to steam power.
514 DISCUSSION : electrification of N". Y. C. & H. R. R. R. [Papers.
Mr. Wilgus. Since July, 1907, the New York Central has not had a single in-
terruption of electrical service, whereas the New Haven Company, on
its own territory north of Woodlawn, has had nine interruptions, of
which four were very serious — in one instance lasting for 38 hours and
necessitating a complete return to steam operation.
These facts demonstrate that, for reliability, the New York Central
installation is far superior to that of the New Haven Company.
(5) Cost. — Comparisons of cost are absolutely valueless unless
they are based on the same premises and conditions, and are in suffi-
cient detail to permit analysis. To make a bare statement, unsupported
by details, comparing the cost of the battery-less New Haven installa-
tion in the open country, with the one on the New York Central carry-
ing four times the traffic through a section requiring expensive ducts
instead of aerial lines, and into a terminal in the midst of a great city,
is like showing side by side the cost per mile of the Union Pacific and
Pennsylvania Railroads, without making allowance for the differences
of topography, grades, number of tracks, terminals, and character of
construction. Mr. Murray's ratio of 5 to 1 is misleading, as will be
shown below.
Mr. Murray questions the accuracy of the saving of $300 000 per
annum by the New York Central from avoiding the use of the alter-
nating-current-direct-current locomotive, but he attempts to analyze
the smaller part ($140 000) only, curiously enough not questioning the
larger portion of the saving ($160 000 per annum) due to the require-
ment for a less number of locomotives. His silence on this point is
most impressive if one considers the millions of dollars that have been
spent by American railroads in grade reductions in order to reduce the
number of locomotives for handling a given traffic — not to increase
them.
Mr. Murray attempts to cast doubt on the statement of lower energy
consumption for the direct-current locomotives by comparing the al-
leged actual results of the New Haven alternating-current locomotive
on direct-current territory, with the theoretical assumptions of an
arbitrator, whose decision, by the way, his company rejected.
Upon carefully checking the correct mileage, weights, and bills for
current, he may also find that his watt-hours per ton-mile should be
50.7 instead of 41.9. However, in the following figures, the writer
has used the figure which is most favorable to his contention.
The energy consumption upon which the item of $140 000 saving
was based, was obtained in the following manner :
Several trial runs were made between the Grand Central Station
and Woodlawn with both alternating-current and direct-current loco-
motives hauling identically the same weight of trains, at the same
speeds, and with the same limited number of stops. The average re-
sults were:
Papers.] DISCUSSION : ELECTRIFICATION OF N. Y. C. & H. R. R. R. 515
Alternating-current locomotive (New Mr. wiigus.
Haven) 36.7 watt-hr. per ton-mile.
Direct-current locomotive (New York Cen-
tral) 28.9
Saving in favor of New York Central loco-
motive, equal to 27% 7.8 " " "
Another comparison is available, as a check on the foregoing results :
New Haven : Average consumption south
of Woodlawn, including more stops
than were made in the foregoing trial
runs 41.9 watt-hr. per ton-mile.
New York Central: Observations for di-
rect-current locomotive, including
more stops than were made in the fore-
going trial runs *. 33.8 " " "
Saving in favor of New York Central loco-
motive, equal to 24% 8.1 " " "
To be well on the safe side, in showing a money saving, a difference
of but 15% in favor of the New York Central locomotive is used in
the following comparisons, this agreeing with a careful study of the
characteristics of the several electrical parts of both locomotives :
New York Central Electric Zone saving, due to use of direct-
current instead of alternating-current-direct-current
locomotives :
Direct-current locomotive annual requirements at
the contact shoes, 36 000 000 kw-hr. at 2t^ cents $936 000
Alternating-current-direct-current locomotive an-
nual requirements at the contact shoes, 36 000 000
kw-hr. plus 15% excess, 5 400 000 kw-hr. = 41400 000
kw-hr. at 2/o cents 1 076 400
Annual saving $140 400
New Haven loss, due to use of alternating-current-direct-
current locomotives instead of direct-current loco-
motives south of Woodlawn:
Direct-current locomotive annual requirements at the
contact shoes, 10 500 000 kw-hr. at 2 -A* cents $273 000
Alternating-current-direct-current locomotive an-
nual requirements at the contact shoes ^ 10 500 000
kw-hr. plus 15% excess, 1 575 000 kw-hr. = 12 075 000
kw-hr. at 2-i o" cents 313 950
Annual loss $40 950
516 DISCUSSION : electrification of N. Y. C. & H. R. R. R. [Papers.
Mr. Wiigus. It thus appears that by adopting a locomotive suited to the system
over which it is to operate, the New York Central will effect a saving,
for current only, over what would have to be expended if a locomotive
had been adopted for operating on two systems, of $140 000 per annum ;
whereas the New Haven Company, by adopting the reverse policy,
will suffer a loss between Woodlawn and the Grand Central Station of
$40 950 per annum.
Mr. Murray asks why not compare the direct-current and alternat-
ing-current locomotives, apart from the complications attending the
necessity of performing two functions by the latter. To do this re-
quires a study of the first costs and annual costs of operation, by both
systems, in the same territory, under precisely the same conditions,
and embracing all variable elements. Therefore the writer has selected
the New Haven Company's line, between Woodlawn and Stamford,
having a total single-track mileage of more than 100 miles, in which
is included a number of small yards. ,
The cost of the generating station for direct-current operation is
found to be at least 20% cheaper than the one intended for alternating-
current operation, for the reason that the generators for the latter, as
built by the New Haven Company, are designed for three-phase out-
put, but they are utilized for single-phase purposes, which largely cuts
down their capacity. Then, too, the magnetizing of the motor fields
of the alternating-current locomotives requires a large amount of watt-
less current not needed with the direct-current system. These condi-
tions result in a much larger generator installation than would be
needed for the direct-current system, and a corresponding higher cost.
To do the same work required on the 41 locomotives ordered by the
New Haven Company, only 28 would be required for direct-current
operation. This is due to the limit of five to six passenger cars to a
single New Haven locomotive in order that the schedule speeds may be
maintained, as compared with the ability of the New York Central
type to make the same schedules with two or three times that number
of cars. In other words, heavy trains require to be double- and triple-
headed with the alternating-current locomotives, whereas but one
direct-current locomotive of substantially the same weight and cost
would suffice. The evil feature of this system is not only the heavier
annual cost for repairs and for current needed by the additional
alternating-current locomotive, but there is the serious operating
handicap of holding spare units in readiness to attach to trains which,
at the last moment before leaving the termini, are found to be heavier
than was at first anticipated. The cost per locomotive of each type is
taken at $30 000, but reliable information points to a considerably
higher cost for the alternating-current locomotive, having approxi-
mately one-half to one-third the capacity of the direct-current loco-
motive.
The effect of this excess number of locomotives is to counteract the
saving due to the superior eificiency of the distributing system of the
Papers.] DISCUSSION : ELECTRIFICATION OF N. Y. C. & H. R. R. R. 517
New Haven Company. For the 28 direct-current locomotives, it is Mr. Wiigus.
estimated that 15 000 000 kw-hr. annually will be required at the con-
tact shoes, based on which the requirements of the generating station
bus-bars, with an efficiency of 81% (New York Central results) for the
distributing system, would be about 18 500 000 kw-hr. The larger
number of alternating-current locomotives for doing the same work
increases the current demand at the contact shoes for the locomotive
ton-mileage, so that, as compared with the 15 000 000 kw-hr. for direct-
current operation, there is needed a 15% increase for the alternating-
current system, or 17 250 000 kw-hr.
On the basis of 95% distributing-system efficiency, this makes the
requirements at the bus-bars of the generating station 18 200 000 kw-hr.
Thus it is seen that, for the two systems applied to the territory in
question, the demands of current at the generating station bus-bars
are nearly alike.
The depreciation of the alternating-current system under New
Haven conditions is greater than that of the direct-current system,
because of the comparatively short life of the trolley wires and catenary
construction, which are subjected to abrasion and corrosion. This
item is aggravated in this instance by the combined operation of elec-
tricity and steam. In both systems, due to deterioration and ob-
solescence, a life of twenty years may be used, except for the trolley
wires and catenary system, for which an extreme life of five years is
assumed. Personal observation prompts the belief that the last named
period is much greater than will be actually experienced.
Maintenance of generating plants and distributing systems is
taken at 2% per annum for both systems. Observations of the annual
costs of maintenance of third-rail and overhead work show that they
are about equal where the conditions are similar, provided that
separate provision is made for the more rapid depreciation of the
latter.
The maintenance of the New Haven locomotives is assumed to be
6 cents per locomotive-mile, as compared with 3 cents per locomotive-
mile for the New York Central locomotive. The excessive number of
locomotive failures, the complication of parts, and the known large
size of repair gangs at Stamford and at the Grand Central Terminal
indicate that the cost of maintenance of the New Haven alternating-
current locomotives is much in excess of the assmned figure. Thirty
thousand miles per annum per locomotive is assumed for both systems.
The actual experience of the New Haven Company with injury to
employees due to contact with 11 000-volt trolley wires warrants the
assumption that payments for damages will be at least five times those
that are chargeable to the use of the third-rail of the direct-current
system. Low clearances at street bridges for trainmen and other em-
ployees; possibilities of falling wires caused by abrasion and corrosion
and from high winds similar to those that recently felled neighboring
wires, trees, and poles, causing a temporary suspension of New Haven.
I-^' f>
4
518
discussion: ELECTRII KTIOX op X. Y. C. 4 11. H. R. R. [Papers.
Mr. wugus. service ; and proximity of sigiiA to the trolley wires — all these ag-
gravate the New Haven situnti:.
With these explanations.
pared.
Comparative Estimatkd <
'Items
I 'iri'«'t iMH ■
ill.iwiiiL' -tatfriu'tits have l^een pre-
IKIKKATIOX 0¥ THE X. Y., N. H.
VI V III ^'l- I VI L» iVf*
AiioriiHunKH'urrent.
Generating
stations
Distributing i
systems Sub-stations $«v*i «»
Working ct>ncluct«>rs,
etc -• '
TransmisHion linmi,
eu-
Rolling stock. 28 locoInoti^
..U«?*, etc.. 730 000
Totals
*Bas.
+ Ba.s..:
reports iudicaic a lii»{U«r ccsi.
Comparative Estim^vted A.nn
Current and Annt\ \
Stamford.
flSQOOOO . 11500(100
■•l«*ni. fouuuu)
12SO00O
41 lucomotiTM ISM 000
$4 000 000*
•n C >mpany's annual
<>y Operation by the Direct-
1 '>>-!KV(<: Woodlawn to
Items.
.Mternatlng-current.
f Int. 40o
Fixed Ciiarges ^ T'^-''*^* '"?';■ ,
" ; Ins. and Risk-
Depreciation.
(Annual sums required to au- i , ,-
cumulate a fund sufficient t'> •^''^'i"" '>te of '.Hj
extinguisli cost at expiratioi "'-^ P«r
of assumed life*
Maintenance.
Generating stations ■^■■. of ,-c a-2fi nnn
Distributing system. . •• • ".-'-•'S ^
Rolling stock :::::::: mm^uos
(a 3c 25 200
Operation 'e.xclujive of mainte-1
;;. I
fing stations 185000(X'*-
I hr. (I ■.,
I cent $92500
1^ sjstem Personaln-
juries.... 5 000
.. ^2w7 000(7?ion*4 000 000 $280000
Assumed life of 20
years, except for
the trollev sys-
tem = 33.B0 per
187 700 SliiOO 8ll7t!0(»
Assumed life
I of trolley
system. 5
I years =
: 1&4.60 per
$1 coo 92 .300
90 200
209 900
V4 of cost... $30 000
... 25 000
1280 000 miles
@6c 7S800
128 800
18200 000 kw-
hr. @ fji
cent $91000
Personal in-
juries 25 000
115 500 116 000
$680 460! $734 700
Papers.] dISCUSSIOX : ELECTRIFICA!:OX OF N. Y. C, & H. R. R. R.
519
'•**a»
Excess cost of alternating-cur-
rent over direct-current north
of Woodlawn 104 240 per annum = 16 per cent.
Add excess cost of operating
alternating-current locomotives
on direct-current territory. ... 40 950 '' "
Mr. Wilgus.
Total excess cost to New Haven
Company by adoption of alter-
nating-current system i 45 190 " " = 23 per cent.
It will thus be seen that, undei'he conditions of traffic on the New
Haven Road, the alternating-currtt system costs 16% more to operate
than the direct-current system, ad if the excess cost of operating
alternating-current locomotives a direct-current territory is con-
sidered, the loss is 23 per cent. 1 in the estimate, consideration had
been given to the use of the muiple-unit cars for suburban service,
instead of locomotives, the direc current system would show even a
greater saving.
Summarizing all the cost £ares for steam, direct-current and
alternating-current service, on kh the New York Central and the
New Haven lines, and adding locciotive wages, so as to agree with the
conclusions given in the paper, tl comparative annual results are:
New York Central ("ltimate Electric Zone).
Steam 1 000 OO thousand car ton-miles
at $2.77 $2 770000
Electric: direct-current. . 1000 0<J thousand car ton-miles
at $2.02 2 020 000
Difference: Saving $750 000
Neav Haven Company Woodlawn to Stamford).
Direct-current.
(Not adopted.)
Al ternating-cur rent.
(Adopted.)
Loss by al-
ternating-
current
system.
Steam
262 503 thousand car ton-
miles @ $3.77 $72\".D
262 500 thousand carton-
miles @ $2.77 $727 125
262 500 thousand car ton-
miles @, $3.11 ± 815 550
Electric
262 500 thousand car ton-
miles @ $2.71 ± 71110
Difference...
Saving $1515
•
Loss $88 425
Add for loss south of
Woodlawn 40 950
$104 240
40 950
Total loss $129 375
$145190
518
DISCUSSION : ELECTRIFICATION OF N. Y. C. & H. R. R. R. [Papers.
Mr. Wiigus. service ; and proximity of signals to the trolley wires — all these ag-
gravate the New Haven situation.
With these explanations, the following statements have been pre-
pared.
Comparative Estimated Costs of Electrification of the N. Y., N. H.
& H. R. R. FROM Woodlawn to Stamford.
t [Items.
. Direct-current. Alternating-current.
Generating
stations
$1300000 JSl 500(100
Distributing
systems
Rolling stock.
Sub-stations $600 000
Working conductors,
etc 800 000
Transmission lines,
etc .550000
1950 000
28 locomotives 850 000
Trolley system . $500 000
Overhead
bridges, etc.. 750 000
1 250 000
41 locomotives 1 250 OOO
Totals
$4 100 000* $4 000 000t
* Based on a liberal estimate of probable cost.
t Based on a liberal estimate of probable cost. The New Haven Cjmpany's annual
reports indicate a higher cost.
Comparative Estimated Annual Costs of Operation by the Direct-
Current AND Alternating-Current Systems: Woodlawn to
Stamford.
Items.
Direct-current.
Alternating-current.
f Int. 4%
Fixed Charges ^J^^^^«|l^
I m%
Depreciation.
(Annual sums required
cumulate a fund sufflci
extinguish cost at expi
Risks r
to ac-")
ent to 1
ration f
J
7% on $4 100 000
Assumed life of 20
years = 33.60 per
tflOOO
$287 000
137 760
90 200
115 500
7% on $4 000 000 $280 000
Assumed life of 20
years, except for
the trollev sys-
tem = 33.60 per
$1000 ...$117 600
2''o of cost.... $26 000
" " " 39 000
840 000 miles
(gi.Sc 25 200
18 500 000 kw-
hr. @ j%
cent $92 500
3@, $6 000... 18 000
Personal in-
juries 5 000
Assumed life
of trolley
system, 5
years —
184.60 per
$1 000 92 300
'""no onn
Maintenance.
Generating stations
Distributing system
2H of cost... $30 000
" " "... 25 000
Rolling stock
Operation (exclusive of
nance).
Generating stations . . .
Substations
mainte-
1230 000 miles
@6c 78 800
128 800
18 200 000 kw-
hr. @ i%
cent $91 000
Distributing system
Personal in-
juries 25 000
116 000
Grand totals
$630 460
$734 700
Papers.] DISCUSSION : ELECTRIFICATION OF N. Y. C. & H. R. R. R.
519
Excess cost of alternating-cur-
rent over direct-current north
of Woodlawn $104 240 per annum = 16 per cent.
Add excess cost of operating
alternating-current locomotives
on direct-current territory. ... 40 950 •' "
Mr. Wilgus.
Total excess cost to New Haven
Company by adoption of alter-
nating-current system $145 190 " " := 23 per cent.
It will thus be seen that, under the conditions of traffic on the New
Haven Road, the alternating-current system costs 16% more to operate
than the direct-current system, and if the excess cost of operating
alternating-current locomotives on direct-current territory is con-
sidered, the loss is 23 per cent. If, in the estimate, consideration had
been given to the use of the multiple-unit cars for suburban service,
instead of locomotives, the direct-current system would show even a
greater saving.
Summarizing all the cost figures for steam, direct-current and
alternating-current service, on both the New York Central and the
New Haven lines, and adding locomotive wages, so as to agree with the
conclusions given in the paper, the comparative annual results are:
New York Central (Ultimate Electric Zone).
Steam 1 000 000 thousand car ton-miles
at $2.77 $2 770 000
Electric : direct-current . . 1 000 000 thousand car ton-miles
at $2.02 2 020 000
Difference : Saving $750 000
New Haven Company (Woodlawn to Stamford).
Direct-current.
(Not adopted.)
Alternating-current.
(Adopted.)
Loss by al-
ternating-
current
system.
Steam
262 503 thousand car ton-
miles @ $2 77 $727 125
262 500 thousand carton-
miles @, $2.77 $727 125
262 500 thousand carton-
miles @. $3.11 ± 815 550
Electric
262 500 thousand car ton-
miles @ $2.71 ± 711310
Saving $15 815
Difference...
Loss $88 425
Add for loss south of
Woodlawn 40 950
$104 240
40 950
Total loss $129 375
$145 190
532 DISCUSSION : pneumatic foundations for buildings [Papers.
Mr. Skinner. They were made excessively heavy, in order to carry the entire weight
of the massive pier and its load, sustained, in the first place, by very
heavy and deep transverse girders reinforced by knee-braces to the
cutting edge, making a costly and complicated construction. Since
that time this type has been entirely eliminated, an advantage largely
due to the improvements described by the author.
One of the first important changes was the substitution of wooden
walls and a wooden deck for steel in rectangular caissons, thus eifect-
ing a reduction in the cost and a greater reduction in the time. The
rectangular caissons were built of solid courses of timber, sheeted and
caulked inside and outside, and with crossed courses of timber, sheeted
and caulked inside, for the deck.
The next considerable stride was made by the substitution of
cylindrical caissons with wooden staves for rectangular ones. These
were more easily made, handled, and sunk, and were more economical.
John F. O'Kourke, M. Am. Soc. C. E., who has built a large number
of difficult and important pneumatic-caisson foundations, is to be
credited with that improvement. His courage, resourcefulness, and
indomitable energy have been important elements in this field. To
him is also due the credit for a simple method of controlling the escape
of air from caissons. In sinking a caisson, it is often difficult to lower
it after the cutting edge has been undermined a considerable distance.
The side friction is sometimes so great that the weight in and on the
coffer-dam is inadequate to lower it, and the air pressure has to be
diminished by letting it "blow out," as it is technically called. A
blow-out is likely to be quite a critical operation, especially if the ad-
joining buildings are on quicksand. Thus the foundations might be
jeopardized if material entered under the cutting edge in large quan-
tities. Mr. O'Rourke simply bevelled the cutting edge, thus providing
a high point which located the blow-out, and that was arranged to be
on the safe side of the caisson.
Still more important, however, and perhaps of greater value than
any other single feature of the development of caissons, has been the
improvement made by D. E. Moran, M. Am. Soc. C. E., in the air-
lock for the passage of materials. The man-lock has been practically
unchanged, but, originally, the air-lock, through which materials were
removed from and introduced into the caisson, was like the man-lock,
and it was necessary, in removing a bucket of spoil or introducing a
bucket of concrete, to detach it from the hoisting tackle and handle it
by separate apparatus inside the lock. That is wholly unnecessary
now, but it was formerly impossible to keep the bucket in uninter-
rupted connection with the derrick.
After considerable experience with caissons, the upper door of the
air-lock was made in two leaves, fitted on the joint line, with a de-
tachable stuffing-box engaging the hoist line. The upper door can
PLATE LXV.
PAPERS, AM. SOC. C. E.
MAY 1908.
SKINNER ON
PNEUMATIC FOUNDATIONS
FOR BUILDINGS.
Papers.] DISCUSSION : PNEUMATIC FOUNDATIONS FOR BUILDINGS 523
now be opened or closed regardless of the position of the line, which Mr. Skinner,
passes freely through it and need never be detached from the bucket.
The stuffing-box permits the bucket to be handled almost as rapidly
and as easily as in an open caisson, and with very small loss of air,
and probably increases the rapidity of removing and entering material
more than 100 per cent. Buckets can now make a round trip in and
out of the caisson in less than 1 min., and previous to this improve-
ment 2 or 3 min. were often required.
Another method of maintaining the attachment of the bucket to
the hoisting line while passing through the air-lock was devised by
Mr. O'Rourke, in the work for the Commercial Building. He made
the top door of the air-lock detachable, and connected the stuffing-box
permanently to it.
Another important development is the special arrangement by
which the exterior caissons supporting the wall columns of several of
the largest and most important buildings in New York City have been
made to form a continuous water-tight wall, or, as it was termed in
one of the first applications, a sort of dam enclosing on some or all
sides the whole site of the building, and thus, theoretically and some-
times actually, avoiding the necessity of using pneumatic caissons
for the interior piers. Having enclosed the building, a flow of quick-
sand from beneath adjoining buildings is prevented, thus allowing
interior piers to be built in open excavations or coffer-dams.
Considerable difficulty is found in making this construction, be-
cause there is a limit to the size of caissons which can well be sunk,
and a length of about 30 It. is a maximum for wall caissons supporting
two columns or, possibly, three. In a building 100 ft. or more in length
it takes several such caissons for the walls. Some clearance must be
left between their ends, and that clearance may be from 4 in. to 12 or
even 18 in., and its closure, and the permanent exclusion of ground-
water and quicksand, in cases where the sand is very lively and the
pressure is heavy, is a difficult problem, and has been jaet in several
ways.
In the Commercial Cable Building, rectangular steel wall caissons
were sunk a few inches apart. Pipes were jetted down between the
adjoining ends, and after they reached the hardpan, 50 or 60 ft. below
the surface of the street, they were filled with clay cartridges rammed
by a piston or plunger operated by a pile-driver. The pipes were
gradually raised, distributing the clay vertically, and such great pres-
sure was developed by the ramming that it sheared the steel plates of
the caisson itself, and very effectively excluded the water until the
hrick lining was built in the excavation.
This method was not in all respects satisfactory, and, not long
after, Mr. O'Rourke devised a method of making a continuous con-
crete bond between adjoining caissons of the Stock Exchange and other
524 DISCUSSION : pneumatic foundations for buildings [Papers.
Mr. Skinner, buildings. As the caissons were sunk, semicircular recesses or wells
were formed in the adjoining ends of both caissons and coffer-dams.
After the caissons were sunk and concreted, men entered and bolted
the adjoining outer wooden walls together, removed the center part,
between the bolts, and caulked the cut edges. The two wells were
thus combined in a single one with a 4 by 5-ft. cross-section and an
outline like that of a button-head rivet, which was filled with concrete,
thus making a key and a bond between the caissons.
ace
Timber
SECTIONAL PLAN
INSIDE ELEVATION
CAISSON CONNECTIONS,
BANK OF STATE OF NEW YORK.
CAISSON CONNECTION AT
N0.42 BROADWAY
CAISSON CONNECTION,
STOCK EXCHANGE.
Fig. 22.
Later, various ingenious methods were used in bonding wall
caissons together. In the Bank of the State of New York the wooden
caissons were sunk about 8 in. apart, and one caisson was provided
with a pair of 2-in. vertical timbers, 12 in. apart, recessed 3 in. into
its thickened wall. These vertical ribs, which projected at first only
very little beyond the face of the caisson, were equipped with 1-in.
stud-bolts or set-screws projecting through the wall of the caisson
and bearing against heavy steel yoke pieces secured by bolts to the
wall of the caisson. After the caisson was sunk, the nuts on all the
screws were operated to force the ribs out through the quicksand until
their sharp cutting edges penetrated the wooden face of the adjoining
caisson, and made a fairly tight and satisfactory joint, excluding the
quicksand from the interior of the excavation.
Papers.] DISCUSSION : PNEUMATIC FOUNDATIONS FOR BUILDINGS 525
Another method of connecting adjoining caissons was made some- Mr. Skinner,
what more simply for the building at 42 Broadway, where the first
caisson was sunk with a couple of vertical 6 by 8-in. guide-timbers
bolted to the end wall, the second caisson being located very close to
SECTION ZZ
.Intermediate Caissoui
SECTION X-X
INTERMEDIATE CAISSONS
FOR WALL COLUMN.
^^ PIERS IN BUILDING OF
TRUST COMPANY OF AMERICA.
Fig. 23.
these guide-timbers and provided with interlocking guide-timbers. To-
gether, they formed a sort of tongued-and-grooved joint, effectually
closing the space, and leaving a small core through which a pipe was
jetted down, thus serving to scour out the sand down to rock and
leave a space for the introduction of grout.
536
DISCUSSION : pneui\:atic foundations for buildings [Papers.
Mr. Skinner. Afterward, still another method was devised by the same con-
tractors. A special sheet-pile was driven in the quicksand across the
gap on both sides of the coffer-dams, protecting the narrow space be-
tween their ends, so that men could enter and excavate down to the
SECTION X-X
JOINING CAISSONS IN
TRUST COMPANY OF AMERICA
BUILDING.
Fig. 24.
deck of the caisson, below which the narrower space was cleared by
post-hole diggers down to the cutting edge and the spaces concreted.
In the building for the Trust Company of America different
methods were adopted for connecting adjoining wall-column piers.
These piers were sunk about 4J ft. apart by the pneumatic-caisson
Papers.] DISCUSSION : PNEUMATIC FOUNDATIONS FOR BUILDINGS 527
process before it was decided to make them continuous. Small inter- Mr. Skinner.
mediate wooden rectangular caissons, of the full depth of the piers,
v.'ere sunk between them, and after they were landed on rock, alternate
horizontal planks, A^, A^, A^, A^, J.^, A^, etc., in the sides next the
large caissons were successively removed, the sand scooped out, from.
the bottom up, and the spaces filled solid with concrete, after whiciu
the caisson itself was concreted, thus sealing the space between the
large caissons or piers. The removal of the side pieces A^, A^, etc.,.
was facilitated by the slots, B, B, B, etc., cut half through them when
the caisson was built. Every other side piece was made without tha
slot, and was left in position to tie the caisson together.
Other pneumatic-caisson wall-column piers in the same building-
were sunk about 12 in. apart, with the intention of joining them after-
ward, and, to provide for this, semi-octagonal recesses 42 in. in diam-
eter were cored in the concrete in the adjoining ends of the piers when
the latter were made, and were closed on the outer faces by horizontal
tongued-and-grooved side boards. A, A, A, making a well, V\\ in each
end of the pier. After the caissons were sunk and concreted, com-
pleting the piers, the earth and sand between them was excavated to
the depth of 1 ft., and the first pair of boards, A, A, was taken out>
cut and nailed on again in the position, A^, A'^, at right angles to their
first positions. This operation was repeated, thus completing the
octagonal well between the two piers. When the well was deep enough,
a short vertical section of a steel air-shaft cylinder was set in it and
concreted, and an air-lock was assembled to it and pressure put on.
Slots, S, S, in the pier concrete were filled with the shaft concrete,,
thus acting as keys to prevent the pressure from blowing out the shaft.
The men then entered and continued the excavation and removal of
the boards, A, A. In this way, the excavation between the piers was
carried to the bottom and afterward concreted, thus making a positive
and efficient bond between the piers, the first time that it had been
accomplished under pneumatic pressure.
A minor improvement in pneumatic-caisson work, but one which
contributes materially to economy and rapidity, is the substitution of
1 000-lb. castings, with connections for hoisting tackles, for the small
pieces of pig iron formerly used to ballast caissons. An equivalent
device is a heavy rectangular box in which is placed 1 000 or 2 000 lb.
of pig iron, kentledge, or its equivalent. These boxes are compact,
and easily handled and piled. Either form of ballast can be much
more advantageously piled around the air-shaft or on the pier than
pig iron, and can be handled very rapidly by a small hoisting engine,
thus eliminating hand labor.
The reference to the connection between concrete piles and pneu-
matic caissons, in the latter part of the paper, is very interesting. The
two are opposite extremes of difficult foundation work, but there is an
528 DISCUSSION : pneumatic foundations for buildings [Papers.
Mr. Skinner, important space intervening between them. The usefulness of a con-
crete pile terminates with the requirements for bearing strength greater
than that of a single pile of such dimensions that it can be advan-
tageously driven. The perfect concrete pile has not yet been devised,
and, for loads of more than about 20 tons, there are few examples of
anything except pneumatic caissons for many cases of pier founda-
tions in soft ground.
Caissons are so expensive and excavation so difficult for piers from
3 to 5 ft. square that there is a very important gap to be filled in the
construction of small piers having a capacity greater than that of a
single pile and less than can be made economically with the pneumatic
caisson. The speaker is not aware of any examples of satisfactory
construction for such cases, but he knows that simple designs have
been made, which appear to be entirely practicable and very economical,
for sinking small concrete piers 3 or 4 ft. in diameter, in soft and
wet ground, without the necessity of pneumatic-caisson or coffer-dam
work.
On general principles, the reinforcement of either a pile or a
pneumatic-caisson pier with steel rods in compression is to be avoided.
Ordinarily, the pier or other foundation should be essentially a
masonry structure; steel reinforcement should only be tolerated when
a bending moment or flexure is unavoidable. For this reason the
speaker does not believe in the use of steel reinforcement for com-
pression stresses in piles or in piers; he is aware that it has been used,
and, further, he is aware that extremely high values have been per-
mitted for steel used in this way in compression; but he has strong
objections to it.
Although the speaker wishes to express the utmost admiration for,
and satisfaction with, the splendid work that has been done in pneu-
matic caissons, yet he thinks the tendency has sometimes been to over-
do it. Pneumatic-caisson foundations are a form of construction es-
sentially and inherently very costly, and, when not indispensable, very '
extravagant. Where equal security can be otherwise obtained, pneu-
matic caissons should not be iised, although in many, perhaps in most,
cases where they have been adopted their use has been unavoidable or
justifiable. In some cases other forms of construction would have
served equally well, and would have avoided excessive expense. The
construction of the caisson is costly, and sinking it is costly. Elaborate
and expensive plants have to be maintained for it, and in some cases
the extreme cost could be obviated by the substitution of piers, sunk
by open coffer-dam work and by other methods.
The use of improved steel sheet-piling will go a great way toward
solving that problem, and reducing the cost of many difficult sub-
structures. Up to the present time, steel sheet-piling, although it has
been used in large quantities, has been of very heavy weight, has not
Papers.] dISCUSSIOX : PNEUMATIC FOUNDATIONS FOR BUILDINGS 52D
afforded absolutely water-tight joints, has been subject to difficulty in Mr. Skmner.
driving, has cost from 75 cents to $1 per square foot and upward, and,
therefore, has often been "thrown out of court," not only on account of
its excessive first cost, but on account of uncertainty in driving.
Recent improvements in design and construction have Tcry ma-
terially reduced the weight and cost of steel sheet-piling, and they
insure absolutely water-tight joints, without caulking or silting. Such
piling can also be driven with perfect protection, so that, no matter
whether the driving be hard or easy, or whether or not there are
moderate obstructions, the engagement of the piles and their perfect
position can be assvired when installed and in service. The piles, with
^-in. webs, can bear a load of 100 lb. per sq. ft. with supports 6 ft.
apart, and may be of any desired width, up to the limits of ordinary
independent driving, say 24 in.
The most important elements of cost for steel sheet-piles are the
joints, the spacing of which has heretofore been determined by the
widths of standard rolled sections, and the practicable dimensions for
driving. Both these considerations have been eliminated in recent
improvements, by which steel sheeting can be installed, before excava-
tion, in units of any width desired, thus reducing its cost almost one-
half, without materially increasing the cost of driving, and by a methoc?
applicable in hard, soft, M-et, or dry, soils. It can be used wherever
it is possible to drive any other kind of sheet-piling, and provides for
sheeting of any dimensions and any degree of strength and stiffness.
The significance of this fact is very important and far reaching;
it means that, not only stiff sheeting can be installed more perfectly
and cheaply than before, but that, where great permanent strength is
not required, a continuous and perfectly water-tight steel surface,
either temporary or permanent, can be installed, which has a minimum
weight and, even with present facilities for manufacture — which can
easily be materially improved — will cost less than wooden sheet-piling.
This piling can be designed to have exactly the strength required,,
without excess of metal. If very thin webs suffice, they can be
strengthened temporarily, to receive the reaction of braces and dis-
tribute pressure, by a facing of loose planks placed as the excavationr
progresses, and afterward removed, thus leaving only the minimum
structure permanently engaged after the work is completed.
There is another point which has not been fully considered: lo
many cases it might be quite advantageous and entirely practicable
to eliminate costly pneumatic-caisson work by enclosing one, two, or
even three or four, sides of the building site by a continuous and per-
fect wall of steel sheet -piling. Suppose that 200 ft. of such a wall
are necessary, and that it is required to be 30 ft. deep. It could be
installed at a total cos1> of from $4 000 to $5 000, exclusive of salvage,
and in many cases would not only protect the foundations of adjoining
530 DISCUSSION : pneumatic foundations foe buildings [Papers.
Mr. Skinner, buildings from undermining and settlement — obviating the necessity
for costly underpinning, in itself much more expensive than the total
cost of the piling — but would also serve as a coffer-dam, excluding a
large quantity of ground-water, so that the foundation piers could be
constructed in open pits, much more rapidly and cheaply than with
pneumatic caissons.
The pneumatic caisson is one of the most indispensable and im-
portant appliances for difficult substructure work; splendid courage,
skill, and energy have been shown in the developments by which it has
been brought to a high state of perfection and simplicity, enabling the
erection of structures which would otherwise have been impossible. It
will continue to be used advantageously in an increasing number ol
cases, but there will be other cases where the great cost of either pneu-
matic or rigid open caissons may be avoided, and perhaps structures
built which would otherwise have been considered too costly, by the
use of steel sheeting, which, besides the advantages mentioned, can be
assembled before driving to form the walls of a complete caisson and
driven sectionally in small units where it would be impossible to over-
come the friction and resistance for the whole caisson at once, and
where the driving effort can be concentrated on a small area of the
structure, thus practically multiplying it greatly and also allowing
for adjustment to conform to the rock surface and obstructions.
Mr. Thomson. T. Kennard THOMSON, M. Am. Soc. C. E. — The author is to be
congratulated on giving such a clear demonstration of the art of
caisson desien ns it oxisted in tlie early port of 1907.
The design of pneumatic caissons has been completely revolu-
tionized about four or five times in the last ten years, and the result
is that what was the best two years ago was out of date last year, and
last year's best is already out of date, notwithstanding the fact that
there is no construction going on at present.
In trying to originate or improve, it is very common to revert un-
consciously to original or antiquated types, and, after using these
designs several times, the same objections which caused the original
to be abandoned become apparent again. For example, the early
caissons were built without coffer-dams on top, as the masonry piers
were generally started on top of the massive wooden structures. To
do this without any coffer-dam, of course, means that the masonry
miast be built as fast as the caisson sinks, as it always has to be kept
above water. This means, first, delay in waiting for the masonry, and
secondly, that the weight of masonry is often greater than required
for sinking, which is dangerous.
It also means that the friction on the sides of the masonry from
the surrounding material is often sufficient to break the fresh masonry
joints; and again, stone masonry causes greater frictional resistance
than plain greased boards. These are undoubtedly the reasons for
giving \ip the attempt to build caissons without the use of coffer-dams.
Papers.] dISCUSSIOX : PXE^:^rATI^ FOUNDATIONS FOR BUILDINGS 531
The first pneumatic caissons under a sky-scraper were sunk for the Mr. Thomson.
Manhattan Life Building, at 66 Broadway, New York City, as
Mr. Francis H. Kimball, the architect, was far-sighted enough to
insist on a rock foundation for his building, and, though he was very
severely criticised at the time, most people have become convinced of
his good judgment, for pneumatic caissons are the only means by
which sky-scraper foundations can be carried to good hardpan or bed-
rock, in lower New York City, without serious danger to surrounding
property. The only material above the hardpan is quicksand which
runs like water, and anybody who attempts to hold back from 25 to 80
ft. gf this stuff by sheeting, etc., will find the results disastrous to the
pockets of the owners of the property. In fact, a great many thousands
of dollars have already been lost through the experiments of novices,
both by the novices themselves and their clients.
The caissons of the Manhattan Life Building were built of iron
plates and angles, without coffer-dams, the brick piers being started
on top of the deck.
Brick masonry has also been found to open at the joints, and allow
the caissons and coffer-dams to separate. Brickwork and stone masonry,
good in their day, have now, it is to be hoped, been entirely displaced
by concrete for caisson work, both above and below the deck. Wet
concrete requires little or no ramming or inspection after mixing,
while masonry of stone or brick cannot be given sufficient inspection.
As timber costs much more than concrete, the less timber used, of
course, seemed to show the greater saving, and it was thought feasible
to replace the timber coffer-dams by temporary forms, as described by
the author.
It was soon found, however, that the apparent saving was very de-
ceptive, for, in the first place, the concrete has to be allowed from 24
to 48 hours to set, and the result is that the sinking has to be inter-
rupted several times, for several days, the men being put to work
elsewhere. To change the men from one caisson to another in the
middle of a shift is, of course, a waste of time; and to keep the air
pressure on a caisson about twice as long as would be necessary with
coffer-dams is obviously expensive, as well as dangerous, for when no
one is working in the air chamber the gauge tender is likely to, and
often has, become careless, allowing the pressure to increase or de-
crease, with disastrous results, especially to adjoining property.
Another reason is that, for economical sinking, it is necessary that
the penetration should be gradual but continuous; plunging a couple
of feet at a time and then waiting for several hours gives the quick-
sand a chance to flow against the sides of the caisson and then adhere
to it. Naturally, if the caisson stands still for a couple of days or
longer, this trouble is much increased, and it is quite difficult to start
532 DISCUSSION : pneumatic foundations for buildings [Papers.
Mr. Thomson, it again, and often requires a great deal of additional weight, usually
in the form of pig iron, thus increasing the expense.
A minor objection to the "forms" is that they are usually con-
nected by iron angles bolted together, and in New York City the Unions
insist upon this being done by the Iron Union, thus making it neces-
sary to keep a high-priced gang for unskilled work. Therefore, the
probabilities are that timber coffer-dams, from the top of the caisson
to the surface of the ground, will be retained.
The omission of the timber or steel roof is often a very decided
saving; but in some cases it would not pay and in others it would be
dangerous, especially where it wovild make the caisson too heavy •to
be handled to advantage. If the caisson with its load is too light, of
course, it will not go down, whereas if it is too heavy it will penetrate
more rapidly than desired, and, as a matter of fact, the cutting edge
has frequently been forced into the ground until the entire working
chamber has been filled with earth, etc. This, of course, would kill
any of the men who were unable to escape, and would make the resump-
tion of work quite tedious, as it would be necessary to remove enough
material to make room for the men and the bucket.
As for the steel shafting, which is expensive, it is often economical
to omit or remove this; but here, again, the question of extra labor
and time will often overcome the advantages, and, in the case of a
5-ft. circular caisson with a 3 -ft. shaft, it can easily be understood
that the omission of the steel shaft would be attended with consider-
able risk, as experience has proved, where the caisson and concrete
have broken apart — c.n rccidei]t almost impossible to rectify when th ^
caisson is from 20 to 40 ft. in the ground.
There have been several cases where this has occurred; and what
assurance is there that similar accidents have not occurred without
fceing detected?
In short, even the most experienced men are often compelled to
learn by experiment, while novices in foundation work must cultivate
a very profound respect for earth and water pressures, or pay the
penalty, which on one contract known to the speaker amounted to
about $75 000.
Mr. Brown. Louis L. Brown, M. Am. Poc. C. E. — There is little than can be
added to this paper, especially considering the remarks made by Mr.
F. W. Skinner and Mr. T. K. Thomson, both of whom are very con-
versant with the subject.
From the standpoint of one whose experience has been closely con-
nected with the actual execution of work of this class, the fact of the
recent improvements in methods cannot be given too much importance.
While it is true, as stated by Mr. Thomson, that there have been
a great many improvements and changes in a very short period of
time, and that sometimes new ideas are tried and found to be unsatis-
factory, still, to make sure on such points, actual trials are necessary.
Papers.] DISCUSSION' : PNEUMATIC FOUNDATIONS FOR BUILDINGS 5,33
One company in New York City has tried and is continually try- Mr. Brown.
ing new methods, for the purpose of cheapening and bettering caisson
construction, and out of the many trials and investigations which this
company has made have come some of the recent improvements such
as Mr. Usina has illustrated.
Not only have the cost of the work and the excellence of construc-
tion been considered, but also the safety of the workers. There is now
in use a shaft which, besides having the features described by Mr.
Usina, is of oval cross-section, with space at one end for the passage
of the bucket and at the other for a ladderway to permit the men to
pass in and out without the risk of being hit by a descending bucket.
This has averted many accidents.
534 MEMOIR OF CHARLES HAYNES HASWELL [Memoirs.
MEMOIES OF DECEASED MEMBEES.
Note.— Memoirs will be reproduced in the volumes of Transactions. Any information
which will amplify the records as here printed, or correct any errors, should be forwarded
to the Secretary prior to the final publication.
CHARLES HAYNES HASWELL, Hon. M. Am. Soc. C. E.
Died May 12th, 1907.
A life of remarkable professional activity, characterized by conspic-
uous public service, came to its close when, on May 12th, 1907, Charles
Haynes Haswell died at his home, 324 West 78th Street, in New York
City.
Mr. Haswell was undoubtedly the oldest civil engineer in the world,
and had he lived ten days longer, he would have entered upon his 99th
year. He was elected a Member of the American Society of Civil
Engineers on January 29th, 1868, and on May 12th, 1905, he was made
an Honorary Member, being one of the forty men upon whom this dis-
tinction has been conferred since the organization of the Society.
A son of Charles Haswell, a native of Dublin, who was in the
British diplomatic service, and of Dorthea Haynes, a member of a
prominent family in the Barbadoes, he was born on May 22d, 1809, in
a house which is still standing on North Moore Street, in New York
City. His education was obtained in the best New York schools of the
time, and was liberal or classical in its character, as no school of ap-
plied science had yet been established in the United States.
At the age of nineteen he entered the service of James P. Allaire,
who was the owner of what was then the greatest steam engine works
in the United States. By close application, he acquired a practical and
thorough knowledge of mechanical and marine engineering, and his
excellent work coming to the attention of the United States Navy De-
partment, he was, in 1835, employed to prepare designs for the ma-
chinery of the United States Steam Frigate Fulton. He had the satis-
faction of superintending the construction of the engines and boilers of
this vessel, as Chief Engineer, under a commission signed by President
Jackson. Afterward, he designed or superintended the building of the
war-ships Missouri, Mississippi, Michigan and Allegheny, and a num-
ber of revenue cutters.
In 1843 Mr. Haswell was appointed the first Engineer-in-Chief of
the United States Navy, his administration of which office was charac-
terized by a devotion to the highest professional ideals, absolute integ-
rity, and rare efficiency. His uncompromising fidelity to duty, as inter-
preted by his ideals and standards, was not always appreciated by those
with whom he had official relations, and in 1851 he resigned from the
* Memoir prepared by Nelson P. Lewis, M. Am. Soc. C. E.
Memoirs.] MEMOIR OF CHARLES HAYNES HASWELL 535
naval service to engage in private practice in New York City, as a
civil and marine engineer. The modern steam yacht is said to have
been created by Mr. Haswell, as the Sweetheart, which was probably
the first vessel of this type, was designed and built by him in Brooklyn,
some time before 1840.
While best known through his connection with steam and marine
engineering, his work covered nearly all branches of civil and mechani-
cal engineering, and as the author of the "Engineers and Mechanics
Pocket-Book," which bears his name, he was known throughout the
world. This book was a standard work of its kind for more than sixty
years, and passed through seventy or more editions. He was working
at his desk upon material for a new edition, when, rising from his
chair, he fell and sustained injuries which resulted in his death the
following day.
During the Civil War, Mr. Haswell was an enthusiastic supporter
of the Union cause. Not only did he go to the front as the representa-
tive of a "Committee of Citizens of New York" and direct the dis-
bursement of funds raised by the Committee, a mission requiring much
tact and discretion, but he was in active service under General Bum-
side, who recognized his excellent work in his reports to the Secretary
of War.
His interest in the affairs of the city which was his birthplace and
home was always keen and unselfish. From 1855 to 1858 he was a
member of the City Board of Councilmen, and, during his last year
of service, he presided over that body. He served as member of a
number of important commissions, and was one of the Trustees of the
Brooklyn Bridge. From 1898 until the time of his death he was Con-
sulting Engineer to the Board of Public Improvements and the Board
of Estimate and Apportionment. He personally made the plans for
and supervised the installation of the heating and power plants for the
public institutions on Hart's Island, and prepared plans for the enlarge-
ment and improvement of Riker's Island. Until within a few months
of his death, he was regular in his attendance at his office, where a
large part of his time was spent over the mahogany drawing board,
concerning which Mr. Haswell wrote in 1904:
"It has been in use 53 years without requiring to be trued. On
it was executed the feat that has become historical both here and in
Europe, that of the delineation of the entire working drawings of the
engines and boilers of the U. S. Steamer Poivlxattan, cylinders 70
inches by 10 feet stroke of piston, the demands upon my time not
admitting of the delay of making a general drawing before furnish-
ing those of the detailed parts."
In the summer of 1904, then in his 96th year, he was retained as an
expert to examine and report upon a boiler plant in Chicago, where he
spent a week in making tests and preparing his report.
Appreciation of Mr. HaswelFs professional work was not confined
536 MLlMOIll OF CHARLES HAYNES HASWELL [Memoirs.
to his own country. More than half a century ago the Czar of Russia
sent him a diamond ring, accompanied by an expression of his thanks
for services rendered to the Imperial Government in sending to it a
number of plans and drawings. The engineers and naval architects of
Great Britain have frequently indicated their high regard for and deep
obligations to him, and during the visit of members of the Institution
of Civil Engineers to America in 1904, he was the recipient of conspicu-
ous attention from them and their President, Sir William H. White.
Those who went to West Point with the visiting engineers will recall
the fact that he walked unaided, down the long line of cadets, with the
reviewing officers and guests, and his tall, erect figure was the most
conspicuous in the party.
He contributed several papers and discussions to the Transactions
of this Society and to the Minutes of Proceedings of the Institution of
Civil Engineers. In 1897 he published his "Reminiscences of an Octo-
genarian," a book which, while lacking continuity of narrative, gives
some admirable and interesting sketches of New York City between
the years 1816 and 1860, and affords evidence of the refined tastes and
admirable public spirit of the author.
Owing to Mr. Haswell's great modesty, he rarely spoke of his per-
sonal achievements or of incidents in which he figured, and it was
difficult to realize the important service which he had rendered to his
profession and to his country. On the rare occasions when he would
indulge in conversational reminiscences, l^e was delightful. His early
education, as already noted, was of the liberal sort, and there was a
refinement in his manner and conversation which showed the influence
of that training. He was familiar with the best literature, and his
Latin quotations, while used without a suggestion of pedantry, fre-
quently gave force to his illustrations and charm to his conversation.
His bearing toward his associates and toward those who were many
years his junior was characteriz'ed by a gentleness and uniform courtesy
which made him a delightful companion and an always welcome visitor,
while his tall, slender figure made him conspicuous in any assembly.
With his keen appreciation of the dignity of his profession, his
high sense of personal honor, and his rare consideration for the feel-
ings of others, he was an admirable example of the old-school, courtly
gentleman of the type which has become all too rare.
Mr. Haswell, in addition to his membership in this Society, was
also a member of the following technical and social organizations :
The Institution of Civil Engineers; The Institution of Naval Engi-
neers of Great Britain; The Naval Engineers of the United States;
The Municipal Engineers of The City of New York; The American
Institute of Architects ; The New York Academy of Science ; The New
York Microscopical Society; The Society of Authors; The Engineers'
Club of New York ; The Engineers' Club of Philadelphia ; and the
Union Club of New York.
Memoirs.] MEMOIR OF JAMES DUN 537
JAMES DUN, M. Am. Soc. C. E.*
Died February 23d, 1908.
James Dun was born on September 8th, 1844, in Chillicothe, Ohio,
and there his early education was obtained. After being graduated
from the Chillicothe Central High School, he attended a private school
at St. Catherines, Ontario, Canada. Later, he returned to Ohio and
received his finishing education at Miami University, Oxford, Ohio.
Mr. Dun began his professional career in 1866, as a member of an
engineering corps working near Indianapolis, Indiana; later, he was
Instrumentman on the survey for the old Louisiana and Missouri River
Railway, between Louisiana and Cedar City, Missouri, now a part of
the Chicago and Alton System.
In 1867 he was appointed Assistant Engineer of the Atlantic and
Pacific Railway, under Mr. Thomas McKissock, Chief Engineer. This
road is now a part of the Frisco System.
From 1871 to 1873 Mr. Dun was Assistant Engineer of the Missouri
Pacific Railway, under Mr. James W. Way, Chief Engineer. From
1874 to 1877 he was Chief Engineer of the Union Depot Company,
and built its yards, and freight and passenger station in the vicinity
of Twelfth Street, St. Louis, Missouri. In 1877 he was appointed
Superintendent of Bridges and Buildings of the St. Louis and San
Francisco Railway Company, and in 1878 was appointed Chief Engi-
neer of the same system, also filling, for a part of the time, the position
of Acting General Manager, during the last illness of Mr. C. W.
Rogers, Vice-President and General Manager.
In 1890 Mr. Dun was appointed Chief Engineer of the Atchison,
Topeka and Santa Fe Railway, and in 1900 was appointed Chief Engi-
neer of the Santa Fe System. In 1906 he was appointed Consulting
Engineer of the same system, which position he held at the time of his
death, which occurred on February 23d, 1908, at St. Augustine,
Florida.
Mr. Dun was elected a Member of this Society on June 7th, 1876.
He was also a member of various other technical societies, including
the Engineers Club of St. Louis, and the Western Society of Civil
Engineers, of Chicago.
His professional reputation was international, and the Frisco and
Santa Fe Systems show to-day the characteristics of his work. The
writer sustained social and official relations with Mr. Dun from
1869 — not continuously, but nearly so — and in all those years has never
seen Mr. Dun's enemy nor heard an unkind criticism.
Broad-gauged, liberal-minded, and with spotless integrity, he rec-
ognized his work and performed it to the letter. Accurate and resource-
* Memoir prepared by J. F. Hinckley, M. Am. Soc. C. E.
538 MEMOIll OF JAilES DUX _ [Memoirs.
ful, with a keen mind for details, and a fund of information acquired
by long and varied experience, he was especially well qualified to sustain
the confidential relations with his superior oflacers which he held for
so many years before his death. Loyal, kind and generous, he was a
most charming companion.
Born a gentleman, he developed into the highest type of manhood.
Full of sympathy for all with whom he came in contact, he was never
too busy to give time to the trouble of his friends, nor counsel to the
young graduate who was looking for an opportunity.
One of his friends — a prominent railroad man who had known him
intimately for more than thirty years — writes as follows:
"I never knew him to do a wrong. His integrity was like the sun's
rays; it came swift from a soul of fire. Nothing deflected him from
the straight course. * * * He sympathized with all men in trouble,
and appreciated the infirmities of human nature; but he never could
understand why men were dishonest. The men in this world who have
never been swerved from the right by either passion or covetousness
have been few : James Dun is the only one I ever knew."
The high esteem in which he was held by his associates cannot
better be summed up than in the words of an old roadmaster who
worked under his direction for many years; upon being told of Mr.
Dun's death, he remarked : "There may have been a better man, but I
never met him."
' o 0 :, I .' ci Q
NORTHEASTERN UNIVERSITY LIBRARIES
3 9358 00841444 0
|W it ^. ,p:^t -;f V^ ,x ..... .
l-r' |t^ -ft' ^#' #: %'■ it ' :f .' 4 '
p It m. -^^:. ^'f '■ " ■" *'■ ■
ri^ w '^% % M ^, !i, .^>' .%• '^
m^ m-
^t f. f-
* 1'
% :f'
i 1^'^ iit
% %
" %' ^^'^ ii' t W" p p "^ ^
^; ■ %
■^. I
*• *
* :*^
#; i
t t.
§ ,^.
#■ Mr
*■ li.:
^ % ¥
l|3 C .1
%■ k^ 1-
^ ^: i.
V W
1^:. -f.
%■ .t ^t:
f. !t^
t: ■ i
m -t. i^
.A ^. ^:
% m h-
- t |b 'i # i #• # W. §i &
,.,. ,. .; m t % # t «^ 1^' ^ i
i. t, i). ^i': %' 'i. t- i' '" ''• '^' "■ ^'
k. :t: %
u -^t -i, ^. , ^ ^
•1 >:' !■ t: t t^ ■■
* t
«. f «:
-.. ,. !»■ jr t' i 1 1^ #: ji ;
., .-: #. If, *; * i. m i' i: 1), f- .H 1j- S^ I^ ^ ■*•
^' ^.; 't:^ t:^ 11 ■¥' ¥ %' f ^: %^ 1^" W >.%• ?^' # ^ ■
, .... . . - ;t p-^ * ^il t'';t' .1' 'I ''^ ^:' ^ 1^'^ feV^-
if-^t' # :t.- # ^|.' t ■¥ :#. f; ii?'' ;is, ^ ;|i^' ^' ^/ ^ i= t -^^ % t ^
:tii. '^t.. %, ••4^., -iL ^t 1^' it' I? .#' :it. ■•^/ j|" ^;v ii^^ •*.: :r >^ i^ # '* j«'
i^- % «t- ,;;li ^' .;»?; .;i %■ !t-' :|^;^ »|^ %; ^' ^ ^' W' t p *' ^1 # l^- I
t ^4 :i|f ::^. :',|. >i..^ % .|^ ^: .|j; .^'- .^ ^:, 'i^i' #■ i^*' i^ i, ^fe % * .>. i
!¥' ^i, *t ^:r' ■^-. #. ^v' ^^' 1^ '^: ^' .t:' ^^' ,1-; t" .|^ f; %; U iS'- ^: ^ ■
^if l^> 1i^ J|^ ^ 4 i.' i^;"- p; ji; :t;: -i?' i^' jh' i. j^ #. ^. ■»■■ i >
It' If lift;* it, ^^ i^: ^9i: ^ t' i% * #' ■%' 'i^'-*'' t t 1. # 1 •¥ !■
^,ii^i€ 1^ ^^^ -'■*' /#;' -i;/*^; i: '^^ # i^' .^i^.; t.' '^ j^- ^r ^ii «^ ^. %
1^,1;^ I*: #. .. :r:' -ir' ^: '^ ||.^ ;i' % y: p % i^ t * it * ^r * ^
.%^.%'^^ *^ * *'•*■* ifc" t * * » f .f ■* 1^ P »:■ .^^ ■#
t-a^-^^" ■ ' '* '*' -t^ *^' «^ * *■'.*-. ^:. » *^: ^: *
*^i^i^ ^it. ..... ,, •., ^. ^; .|. ^ ^ ai; m t -iiy' -i n #v 1. ^ i
■ m^ ■ =i' ^^* %■ ^' w M ^ ^- ^ ■%■ p #■■ ^- ^'
.»«: ■'Ji