City Document, — No, - 14.
CITY OF BOSTON
a^ me c(^?nAumen/d o/ me
City Document. — No. ■ 14.
CITY OF BOSTON
CITY OF BOSTON.
Office op City Engineer, City Hall,
Boston, January 10, 1870.
To the Honorable City Council :
In compliance with the sixth section of the ordinance relating
to the City Engineer's Department, I have the honor to present
the following report, viz :
The ordinance above alluded to was passed October 12,
1868, and differs from the previous one mainly by effecting a
complete separation of the Departments of Engineering and
Surveying, which were partially distinct before, and under the
control of two heads or officers. Each department is now dis-
tinct and independent, with well defined duties.
The change had become not only mutually desirable to the
officers in charge of said departments, but imperatively neces-
sary to the thorough efficiency of each organization, owing to
the enormous increase of work called for by the numerous and
extensive schemes of public improvements already initiated, and
those in contemplation.
Although the ordinance went into effect upon- its passage,
and the City Engineer and City Surveyor each assumed charge
and control of their special business as defined by the ordi-
nance, yet it was found impracticable to immediately reorganize
the working force so as to assign to each department the assis-
tants required, and, as the Auditor decided that the appropria-
tions could not well be divided, it was thought best to continue
the old system of using the same force of assistants and em-
ployes in common until the close of the financial year 1868-9.
New rooms were assigned to this department, which were
4 City Document. — No. 14.
furnished and occupied in February, and a division of the plans,
note-books, furniture, etc., was then made. The experience of
the few months that had intervened since the passage of the
ordinance, proved that it would have been impossible to have
maintained the old system much longer; that the combined force
of the two departments had already become inadequate, and
that besides the additional room required, a reorganization and
enlargement of the corps of assistants was imperatively neces-
sary. The work of organizing a force for this department, and
getting fairly at work under the new system, interfered for a
while with the work of the department ; but, by the middle of
March, the new office was pretty well equipped, and, so far as
this department is concerned, I am satisfied the change has
The following is a statement of the expenses of the City
Engineer's Department, as paid from the appropriation for the
Amount of appropriation .
Salary of City Engineer, and amounts
paid assistants, draughtsmen, rod-
Instruments and repairs of same .
Drawing paper and materials .
Stationery, note-books, etc. .
Cloth and labor mounting and bind-
Incidental expenses, tools, stakes.
postage and revenue stamps, and
expenses of committee
Books and picture-frames
Eeport op City Engineer. 5
The following: statement shows the amounts paid since Jan-
uary I, 1869, for engineering, from special appropriations:
Chestnut Hill Reservoir : pay rolls
and incidentals . . . $4,805 03
Roxbury extension (Wards 13, 14
and 15) : pay rolls and incidentals 1,448 89
Deer Island water-pipe : pay rolls
and incidentals . . . 143 18
Atlantic avenue : pay rolls and inci-
dentals $434 24
Broadway extension : pay rolls and
incidentals, etc 1,176 79
CHURCH STREET DISTRICT.
Pay rolls and travelling expenses . . . $565 50
Total from special appropriations . . . $8,573 63
The number of persons employed and paid from the de
partment appropriation was, on the 1st of May (includ
ing the City Engineer)
The present number is ..... ,
The Chestnut Hill Reservoir party numbers
The following statement exhibits the operations of the de-
partment during the past year :
Several designs for a stand-pipe for the Roxbury high service
were prepared, and detailed drawings and specifications made
6 City Document. — No. 14.
for the plan finally adopted. Plans and specifications have also
been made of the pumping engine house, and numerous draw-
ings of special castings for the extension of the works in the
Two large plans of Roxbury, comprising also portions of the
city proper and South Boston, have been made, upon which are
shown the water pipes, hydrants, and gates as already laid in
the said portions of the city proper and South Boston, and the
connection between the same and the newly laid pipes, etc., in
Roxbury. These plans show the sizes and location of all the
mains and distributing pipes laid, and the location of all hy-
drants and gates established up to January 1, 1870. Two
other large plans of the Highland District have also been
made : one showing the location of all houses whose door-sills
are more than eighty feet above " tide marsh level," with the
actual height of said sills ; and the other showing the elevations
and depressions of all the streets, and the exact height in
figures above " tide marsh level " of all points in the streets
where a change of grade occurs. These plans were prepared
in order to determine the line of separation between the high
and low service, the boundaries and extent of the high service
districts, the location of blow-offs and air-cocks, and also to
show at a glance the exact pressure to which the pipes will be
subjected at any given point, whether in the high or low service
system of distribution. A description of the high service dis-
tricts, as determined by the aid of these plans, will be found in
my report to the Cochituate Water Board, which is embodied
in the last annual report of that Board.
A copy has been made of the map of Dorchester, which was
compiled for the commissioners on annexation, by T. W. Davis,
Esq., City Surveyor. Upon this map will be shown the loca-
tion of all buildings, the elevation of all door-sills above a plane
of eighty feet above " tide marsh level," the heights of the sum-
mits of all hills, the elevations and depressions of the streets,
Report of City Engineer. 7
and a proposed system of water-pipes, hydrants and gates for
the distribution of the water. A party is now engaged upon
the field work, and rapid progress is being made.
A compiled map has also been prepared on a scale of 500 feet
to an inch, showing Boston and its environs south of Charles
River, and as far west as Watertown village. Upon this map it
is designed to delineate such general topographical features as
will be of service in planning the future extensions of our water
supply and distribution. It will also be of service as a map of
reference in the discussion of tlie question of public parks, and
the further extension of our corporate limits.
Three plans of East Boston have been made, showing the
sizes and location of the water-pipes laid, and the position of
hydrants and gates established. One of these plans was made
for the use of the Mystic Water Board, of Charlcstown, one for
the Superintendent of the eastern division, B. W. W., and one
for office reference, and upon which to delineate future addi-
A copy of the plan of South Boston, made under the direction
of the commissioners appointed to define the bounds of the
streets, has been prepared for the use of the Water Depart-
ment, upon which to show the water-pipes, gates, etc.
A plan, on a scale of three hundred feet to tlie inch, has been
made, showing tlie proposed extension of Swett street, across the
South Bay to the junction of Dorchester and Federal streets,
and also the route for a new main water-pipe to South Boston,
from the junction of Dudley and Hampden streets, via Magazine
street, the aforesaid extension of Swett street, Dorchester, Tele-
graph and Thomas streets, to the reservoir on Telegraph Hill.
This plan was designed to show the general features of the pro-
jects. Surveys have been commenced, and are now in progress,
to enable the construction of a plan upon a larger scale and
exhibiting more details.
Surveys iiave been made and a plan and profile prepared of
8 City Document. — No. 14.
the route for a pipe from East Boston to Deer Island, including
soundings of the Cliannel or " Gut," between Point Shirley and
the island. This survey was made by order of the President
of the Water Board, after the appropriation had been passed by
the City Council. The low grade of a portion of the highway
in the town of Winthrop, necessitating the laying of a portion
of the pipe below tide water, unless the town will fill up or alter
the location, and the question of the necessity of laying a larger
size of pipe than was estimated for, over a portion of the route,
has delayed action. These questions will undoubtedly be set-
tled soon, so that the work may be commenced in the early
Surveys have been made, and a plan nearly completed, which
will show the proposed limit of the Beacon Hill high service,
the number of houses, hotels, etc., within the district, and the
elevations of their door-sills and cisterns above " tide marsh
level." Observations by means of pressure gauges will deter-
mine the line of division between the high and low service. A
variety of calculations have also been made, bearing upon the
best mode of supplying this elevated district as thoroughly and
efficiently as it is proposed to do the Roxbury high districts, and
a report now in progress will soon be laid before the Cochituate
Plans have been made of various alterations in the brickwork
of the effluent gate house at the Chestnut Hill Reservoir, and of
the iron railing, stairs and galleries in said gate house, and the
gate chamber connected therewith.
Finished drawings have also been made, and others are in
progress, which will show all the structures connected with the
reservoir, just as they had been actually built. The work
upon these finished drawings is kept as reserve work, to be done
in leisure time, when current work is not pressing. A very
considerable amount of time was consumed in preparing the
estimates and statements called for by the Water Board last
Report of City Engineer. 9
spring in connection with tlie request then made for an addi-
tional appropriation for completing the reservoir. These esti
mates and statements may be found in City Document No. 59,
Very few clianges have been made or required in the work
at this reservoir during the year, aside from those previously
alluded to at t!ie effluent gate house. It was found necessary to
strengthen the retaining wall which supports the filling of a
portion of the driveway, and a plan prepared by Mr. Wight-
man, the Resident Engineer, was approved, which accomplishes
the object by building a supplementary wall, connected by stone
piers with the old one, and forming a terrace along the entire
The plans for the gate chambers at Brookline, for inclosing the
gates, rendered necessary by the joining of the 48-inch main
from the Chestnut Hill Reservoir with the three mains which
now supply the city, were also prepared by the Resident En-
"With the exception of the slight changes above referred to,
the general plans of the work were well matured early in the
year, and the work of executing the same and completing the
reservoir was in that state of forwardness or maturity that it
needed only the well-known executive ability of the Superinten-
dent and Resident Engineer to push the work as rapidly as pos-
sible towards its final completion, and the result shows that
they have done their duty.
The report from this department to the Water Board in May
next, will present in* detail the progress of operations on this
work as well as of the extension of the works in Roxbury and
Dorchester and the general condition of the whole.
Soundings were made at the beginning of the year on the
easterly line of Atlantic avenue, where it crosses the several
10 City Document. — No. 14.
docks, and levels taken of the whole line, from which profiles
were made showing the elevations of the existing piers and
wharves above mean low water, the depths of water at low tide,
and the depth of mud or other material overlaying the hard
bottom in the several docks ; also, the proposed grade of the
avenue as recommended by the Superintendent of Streets, which
grade was fixed at an elevation of sixteen feet above mean low
water for the whole line from Commercial street to the north-
erly side of India wharf; thence rising at the rate of about .j^^^^
of a foot in one hundred feet to meet the grade of Broad street
as previously fixed.
The depth of water below mean low tide and of the mud, was
found to vary very materially in the difierent docks, and the
hard bottom appeared to be of the same character as the mate-
rial of Fort Hill, a mixture of clay and gravel, very hard and
compact, and what is commonly called " hardpan."
The first plan proposed for a sea-wall contemplated the exca-
vation of all the mud and objectionable material for a space of
about twenty-five feet in width at the bottom of the trench under
the whole line of wall, and of building the wall solid from this
foundation, without using piles, to the grade of the street.
This plan would have called for a wall whose average height
would have been thirty feet, fourteen feet of which would have
to be laid under water, below the level of low tide, whose
width at the base would be seventeen feet, at low water thir-
teen feet, and at the top three feet, the rear of the wall to be
heavily ballasted. This plan, although the most substantial, was
also the most costly, and was deemed too expensive.
Another was proposed, the wall resting upon a foundation of
piles cut off at a level of one foot below mean low water, and
placed three feet apart on centres longitudinally, and two feet
transversely of the wall. The principal objection to building
a wall designed to support a heavy earth filling, as in this case,
upon a pile foundation, where the mud is soft and of considerable
Report op City Engineer. 11
depth, is that the mud being soft and yielding, affords very lit-
tle lateral support to the piles, and the weight of the filling ia
the rear presses upon the mud as upon au elastic cushion, which,
moving laterally, tends to crowd the piles outward, and over-
turn the wall. To avoid this objection it was proposed to
excavate a trench as in the first instance, removing all the soft
and yielding material, and to replace it with good clean gravel
in part, and in part with broken stone ; thus the piles would be
surrounded with a firm, unyielding material that would hold
them in place, and the danger to the wall from the spreading of
the mud would be avoided. This plan was deemed amply
secure, and as its cost per running foot was estimated at about
fifty dollars less than the first, it was approved and specifica-
tions were drawn.
A practical difficulty, however, made it necessary to slightly
modify the plan of the wall, to change its location, placing it
twenty feet back from the line of the street, and to build a plat-
form sidewalk resting upon oak piles outside of it. This change
was rendered necessary from the fact that the plan of con-
struction of the wall as approved, required that a portion of
the trench to be excavated as described above, and afterwards
filled with stone ballast, was necessarily in front of the wall,
and being outside the limits of the street, upon private ground,
the city would be a trespasser unless the consent of the owners
could be obtained. Efforts to procure this consent were unsuc-
cessful, and hence the adoption of the modified plan. Proposals,
however, were invited and received upon both plans, and the
contract, which was awarded to Boynton Brothers, was so
drawn that either plan could be executed in part or the whole,
as the Committee on Paving should direct. Both of the plans
and the specifications were approved by a majority of the Har-
bor Commissioners, and copies of all plans referred to in the
specifications were made and deposited in said commissioners*
The contract was awarded to Boynton Brothers, and was
12 City Document. — No. 14.
duly executed on the 4th of March, 1869. The contractors
were to commence work on or before the 10th of March, and
complete the whole on or before the tenth day of October.
They were to receive for so much of the wall as should be built
according to ^^ Plan No. 1" (the second above described),
$92.50 per lineal foot; for so much as should be built accord-
ing to " Plan No. 2 " (with platform sidewalk, but not including
the same), $91.82 per lineal foot; for all sluices which might be
found necessary, built according to the plan, $11.17 per lineal
foot; and for the platform sidewalk, $25 per lineal foot; all the
work to be done to the approval of the Committee on Paving
and the Superintendent of Streets, or some person appointed
by them to superintend the work. A superintendent, Mr.
Leighton, was appointed by the Committee on Paving, and the
work was promptly commenced under his direction and super-
vision, and would probably have been completed at or near the
appointed time, but for changes in the plan of construction which
the contractors were ordered to make by the superintendent in
charge of the work.
These changes had been discussed by the superintendent
and myself, and I had given a conditional verbal assent, subject,
however, to the approval of the Committee on Paving.
The superintendent, understanding or claiming that he was
authorized by the chairman of the committee to make the
change, if I approved of it, and being ignorant of the fact that
such change required the approval of the Harbor Commis-
sioners, directed the contractors so to alter the plan of construc-
tion of a certain portion of the wall as to omit the dredging,
where the mud was only seven or eight feet deep, and substitute
small stone chips or ballast for the gravel filling between the
piles and in the rear of the wall up to the level of the tops of
Acting upon the orders of the superintendent, the contractors
proceeded to drive the piles for the foundation of the wall in
Report op City Engineer. 13
the dock between T and Commercial wharves, — omitting the
preliminary dredging, — and had made considerable progress,
when the fact was reported to the Committee on Paving by the
Harbor Commissioners, accompanied by a statement that the
change which was being made would result in a saving to
the contractor of over forty dollars per running foot of wall.
The work upon this section was at once stopped by order of
the Committee, the Harbor Commissioners positively refusing to
sanction the change, and the Committee on Paving disclaiming
the authority of the superintendent in ordering it ; while the
contractors, insisting that they had acted in good faith in com-
plying with the orders of the superintendent, whom they re-
garded as the authorized agent of the committee, declined to
undo the work already done, and proceed according to the
specifications, without due compensation.
A modified plan was proposed by the Harbor Commissioners
which they deemed an equivalent to the original, and by which
the work already done might be saved ; but this plan was pro-
nounced impracticable by the superintendent, and the contract-
ors refused to accept it as an equivalent for the original.
Several conferences were held between the committee, the
Superintendent of Streets, the City Engineer, the superintendents
(Mr. Leighton and T. W. Pratt) and the contractors, and it was
finally decided that the City Engineer and Mr. Pratt should con-
fer with the Harbor Commissioners, and, if possible, devise a
plan which should meet their approval, and that in devising such
plan the engineers need not consider the question of equiva
lency at all. Plans were accordingly made and submitted to the
commissioners, which met their approval and that of their en-
gineers. The plans were then laid before the contractors, who
expressed their willingness to execute them, but demanded an
additional sum per running foot.
The question of what should be equitably paid the contract-
ors, in addition to the original price, was referred by the com-
14 City Document. — No. 14.
mittee to the City Engineer and T. Willis Pratt, who, after
several fruitless conferences with the contractors, reported the
additional amount that should be paid for the section between T
and Commercial wharves at nine dollars and forty-one cents per
lineal foot, and for a short piece between T and Long wharves,
four dollars and twenty-two cents per lineal foot.
These prices were finally accepted by the contractors, and a
new contract made in October, under which the work is now
progressing and by the terms of which the whole work is to be
completed on or before May 1, 1870.
It should be explained in this connection that the statement,
above referred to in the communication of the Harbor Com-
missioners, that the change ordered by the superintendent would
result in a saving to the contractors of over forty dollars per
running foot, was undoubtedly made under a misapprehension of
facts both as to quantities of material and the prices ; for I
found, by careful estimates, that tlie actual difference in cost to
the contractors would be inside oi fifty cents in their favor,
while the contractors claimed that the balance would be on the
other side. In fact, such a misapprehension is evident when it
is shown that the entire cost of dredging and gravel filling in
this particular dock would not have exceeded five dollars per
running foot, and if all the broken stone required had been
omitted, the cost of that would have been only nine dollars per
In my judgment, the modified plan of construction as ordered
by the superintendent would, in that particular dock, have been
equally as secure as the original, and would have expedited the
work very materially. But as the Harbor Commissioners
thought differently, and had absolute legal power in the prem-
ises, the work was necessarily delayed in this locality for several
months, and was finally resumed at an additional cost of over
nine dollars per running foot.
The work is now progressing favorably, and is in that state of
Report op City Engineer. 15
forwardness that there is every prospect of its completion at
the appointed time.
The final grading and paving of Oliver street was completed
in August, and in the fall the work of excavating the main body
of the hill was commenced on the easterly side at the level of
Purchase street, under a contract for filling Atlantic avenue,
made with B. N. Farren, Esq., on the 27th of October, 1869.
All material removed is measured in the bank, and monthly
estimates of the amount so taken are made by this department
and certified to by the City Engineer.
CHURCH STREET DISTRICT.
In tlie early part of the year the final estimates were made
of the amount of gravel removed from the bank at Readville,
and deposited in this district. Since then the necessary sur-
veys, levels and estimates have been made to determine the
amount of gravel removed from the banks at Monterey and Mt.
Hope, and used for filling on this territory. The amount of
filling from other sources has also been determined and certi-
A general plan for the bridges and necessary structures re-
quired for the extension of Broadway at " the high grade " was
prepared under my direction in 1867. This was designed more
especially to illustrate the main features of the " high grade "
project, and, at the same time, afford the necessary basis for the
preliminary estimates of cost.
The necessary orders for the extension at the " high grade "
were passed by the City Council in the latter part of April, by
which the Committee on Paving were authorized to make all
contracts for the execution of the work.
The work of preparing detailed plans and specifications of
16 City Document. — No. 14.
the bridges and piers was commenced on the following week by
Mr. Clemens Herschell, C. E., well known as the designer of
the Columbus avenue bridge over the Boston and Albany Rail-
road, the Albany street bridge over the same railroad, and of
the Public Garden bridge. He had been engaged by the Com-
mittee on Paving to do the work under the direction of this
department, the expense to be charged to the appropriation for
Before much progress had been made by Mr. Herschell, plans
and specifications were presented to the committee by the Mose-
ley Iron Bridge Works Co., with which the committee were so
well pleased, that the same were referred to me for my opinion
as to style and strength. Although confined at home by ill
health, I examined the plans and specifications as requested,
calculated the strains of the various parts, and noted my objec-
tions. Subsequently, the plans were returned to me with addi-
tional details, and the specifications in a new draft for re-exam-
ination. I suggested some further slight changes that would
be necessary before I could give my approval; these were
promptly made by the Bridge Co., and my approval was given
to the committee on the 24th of May. Mr. Herschell's designs
and specifications not being ready at this time, and the com-
mittee not feeling satisfied with the progress made, accepted the
Bridge Co.'s plans, and at once advertised for proposals, to be
received until June 7th, for building the bridges, etc., according
thereto. The contract was awarded to the Moseley Iron Bridge
Co., and the necessary agreements were prepared, dated June
The plans and specifications, though approved and adopted
by the committee, had yet to receive the sanction and approval of
the Harbor Commissioners before the work could begin; for,
by the terms of the act of the Legislature, authorizing the exten-
sion of Broadway and the building of a bridge over Fort Point
Channel, the work must be done under their supervision and
Report op City Engineer. 17
direction. The plans were retained for a considerable time,
and were tliorouglily and critically examined by their engineers,
and several changes were prescribed, some of which, in my
judgment, were judicious, and some not ; but nearly all were of
a nature to increase the cost of the work quite materially. By
the terms of the contract, the entire work embraced in the speci-
fication is to be done to the satisfaction of the City Engineer,
the Committee on Paving, the Superintendent of Streets, and
the superintendent in charge of the work on the part of the
city, for the sum of $331,708.76.
As this is one of the most important structures of the bridge
kind ever erected in the city, a description of it may be of in-
terest, and not out of place in this report.
The structures embraced in the contract with the Moseley Iron
Bridge Co. include everything except paving, between the east-
erly side of Foundry street in South Boston and the north-
westerly side of Lehigh street in Boston proper, a distance of
Beginning at tlie easterly side of Foundry street, the first
structure is an iron bridge over said street of a clear span of
fifty-six feet, and at an elevation of twelve feet in the clear
above the same. This structure is to rest upon a substantial
stone abutment built by the city on the easterly side of the
street, and upon wrought-iron columns built by the contractor
on the westerly side.
The bridge is a modification of the style known as the " Bow-
string Girder," and consists of two main wrought-iron arches
springing from shoes or sockets at the ends, which rest upon the
abutment or pier, the ends being tied together by a horizontal
tie, or what is usually called the lower chord. This lower
chord and the floor beams or cross-girders of the roadway and
sidewalk are suspended from the arches by vertical suspension
bars. Besides the arches, a supplementary horizontal boom or
upper chord of wrought-iron is provided and attached to the
18 City Document. — No. 14.
arches at the crown, adding greatly to its strength, and, by
means of the vertical and diagonal bars connecting said chord
with the arches, forming a spandril-bracing, the stablility of the
arch, nndcr a travelling load, is greatly increased. The height
of tlie arches in this span is five and one-half feet from the
lower chord to the upper chord at the centre.
Each arch and the attached upper chord combined is to have
a sectional area of twenty-six square inches, and each lower
chord at its centre a sectional area of twenty-six square inches,
exclusive of rivet holes. The vertical suspension bars to be of
bar-iron, three inches by f -inch, and to be placed two feet apart,
and the diagonal or lattice bars to be two inches by l-inch,
the intersections of these bars to be covered with ornamental
castings. Stays or bracings, of 3-inch T iron, are to be placed
eight feet apart to give lateral stiffness to the arches. The
floor-beams or cross-girders are to consist of double 9-inch
wrought-iron I beams, brought into compressive strain by ten-
sion rods of two inches diameter, attached to the I beams be-
neath the main arches, and strained over struts of cast-iron.
These beams project beyond the arches to form a support for
the sidewalks and are placed four feet apart. Upon these iron
floor-beams or cross-girders are to be laid, for the roadway,
cast-iron plates four feet square and ^-inch thick, ribbed twice
across the surface by ribs three inches by |-inch at the mid-
dle, and tapering toward the edges. This completes the road-
way ready to receive the wooden pavement, which is to be
furnished by the city.
The sidewalks of this bridge and throughout all the struc-
tures hereinafter described, are to be floored with yellow pine
three inches thick. The railing for the sidewalks is to be uni-
form throughout the whole length of the several structures, and
is to consist of an upper rail of double 21 inch I iron, middle
and lower rails of double 2-inch I iron, with vertical rods |-inch
diameter, placed six inches apart on centres and diagonal rods
Report op City Engineer. 19
J-inch diameter, — the intersections to be covered with orna-
mental castings. Stays or bracings of 3-inch T iron will be in-
troduced wherever required to give lateral stiffness.
The next structure extends from the last described, to a point
on the easterly side of the Old Colony and Newport railroad
tracks, a distance of about four hundred and forty feet. In
this structure the street is supported upon wrought-iron columns
set in rows of three, crosswise the street, twenty feet apart;
the rows being eleven feet apart, lengthwise the street. The
roadway being forty feet wide, and the middle column of each
row being placed in the centre, the two outer ones come diretly
under the sidewalk curb, and the sidewalks — each ten feet
wide — are supported upon wrought-iron brackets attached to
the outer columns. These columns are twelve inches in diam-
eter and ^-inch thick, of the Phoenix Company's make, and
are each supported by three piles cut off two and one half feet
below mean high water, and capped with stone to a point four
feet below the surface of the ground. That portion of the
column which comes below the surface of the ground (four feet
deep) is enclosed in boxing two feet square, and the space be-
tween the boxing and the column is filled with concrete com-
posed of broken stone or gravel, and hydraulic cement.
The columns themselves are also filled solid with concrete,
and are then capped with a cast-iron cap, so formed on its
upper side as to receive and hold in position the transverse
girders, which are 12-inch wrought iron I beams. These I
beams project beyond the outer columns, and rest upon the
brackets before described, forming the support for the sidewallc.
Upon these 12-inch I beams, longitudinal beams of heavy 6-incIi
I iron are placed under the roadway, and are four feet apart
from centre to centre. Upon these rest the cast-iron plates
four feet square, similar to those above described.
The last or westerly row of columns, near the Old Colony
and Newport Railroad, supporting the structure just described,
20 City Document. — No. 14.
differs from the others inasmuch as it forms a pier upon
which is to rest the southerly end of the long span bridge here-
inafter described. The number of columns in this pier is the
same (three) ; but the two outer ones are to be twenty-four inches
in diameter, and y^g-inch thick, and the middle one twelve
inches by one-quarter, like the others. These columns are to
be connected at the tops by a pedestal constructed of 15-inch
wrought-iron I beams, securely fastened. This pedestal forms
the southerly bridge seat for the next structure, which is a
bridge of one hundred feet span, extending from the last de-
scribed pier, over the tracks of the Old Colony and Newport
Railroad, at an elevation of fourteen feet in the clear above
said tracks, to a pier in Fort Point Channel situated about
eighty feet southeastwardly from the centre of said channel.
This pier is to consist of five cast-iron screw-piles, of twenty-
four inches internal diameter and one and a quarter inches
thick, so placed that two of them cotne directly under the ends
of the adjoining arches on each side of the roadway, and one
under the centre of the roadway.
These screw-piles are coated with a coal-pitch varnish, which
has been in successful use for several years in protecting water-
pipes from corrosion. The sections are joined by bolting the
projecting flanches firmly together. They are to be screwed
into the clay bottom until a firm and substantial bearing is ob-
tained, and then the soft material is to be removed fiom the
interior, and the pile filled with hydraulic concrete and capped.
Upon these piles, and connecting them at the tops, is to be a
pedestal of wrought-iron I beams, fifteen inches high and f-
inch thick at stem, securely fastened to the piles, and widened,
if necessary to receive the ends of the bridges properly, by
brackets. Diagonal tie-bars four inches by ^inch will connect
the outer piles with the middle one.
The bridge of one hundred feet span, which rests upon the
piers above described, is of the same style as the one above
Report op City Engineer. 21
described over Foundry street, differing only in dimensions and
proportions, and in the style of flooring.
The main girders or arches in this bridge are to be ten feet
high from lower to upper chord, and are each to have a sec-
tional area of fifty-six square inches for the arch and upper
chord combined, and fifty-four square inches for the lower
chord. The suspension-bars, lattice-bars, and ornamental cast-
ings, and also the floor-beams or cross-girders are to be pre-
cisely the same as in the Foundry street bridge ; but, instead of
cast-iron plates, the flooring will be of wood, consisting of 8-inch
by 4-inch Burnettized spruce timbers fitted between the iron
floor beams, flush with their tops, and placed three feet apart on
centres, to which is spiked an under flooring of 3- inch Burnet-
tized spruce plank, upon which an upper flooring of 3-inch white
oak plank is laid at right angles therewith, and spiked thereto.
The pivot drawbridge and pier are the next structures in
order, and are located nearly in the centre of the channel. The
openings for the passage of vessels are about forty-four feet
each, and the whole length of the bridge is one hundred and
sixty feet, and rests upon a central and two end-piers. The
southerly end-pier has just been described; the northerly pier
is of precisely the same description. The central pier upon
"which the bridge turns is composed of cast-iron screw-piles of
the same dimensions as those already described. Sixteen of
these piles are placed in the circumference of a circle of about
forty feet diameter, being about eight feet apart, and three are
to be set at the centre in a line with the current of the stream.
Each of the outer piles is to be connected with the central ones
at the top, and also at a level of eight feet below the tops of the
piles by radial 6-inch wrought-iroa I beams, firmly bolted to
clasp-rings encircling each pile.
Similar I beams will also connect the outer piles with each
other at the same levels, and diagonal rods crossing each
22 City Document. — No. 14.
other will connect the top of each outer pile with the lower
clasp-rings of the adjoining piles. Upon the caps of the
outer piles is to be a pedestal of 15-inch wrought-iron I
beams, curved to form a true circle and securely fastened to the
piles; and, to the top flanch of this beam, a steel-headed track-
rail, weighing not less than iifty-seven pounds per yard, is to be
bolted. Upon this track-rail rest the wheels which support the
turntable. These wheels are to be of cast-iron, chilled, sixteen
inches in diameter, with a face or bearing surface six inches
broad and truly coned to the radius of the circle. They will
be placed about four feet apart. Radial rods, two inches in
diameter, pass through the centre of each wheel, connecting it
with a central hub eighteen inches in diameter. The outer enda
of these radial rods project and pass through a curved wrought-
iron band, four inches by J-inch, which extends entirely around
the circle just outside the wheels and keeps them always at
equal distances apart and insures a uniform motion. A 6-inch
wrought-iron pivot passes through the aforesaid hub at the cen-
tre, and extends downward through the cap of the centre pile,
and three feet into tlie concrete filling ; it also extends upwards
and passes through a heavy cast-iron disc-plate five feet square,
and one and one-half inches thick. Fastened to this central disc
are to be radial 7-inch wrought-iron I beams, connecting it with
a ring composed of 15-inch wrought-iron I beams, to the under
side of which is bolted a steel-headed rail similar to the one
above described. This ring is an exact counterpart of the cir-
cular pedestal before described, only it is inverted and the
track-rail rests upon the tops of the wheels. Circumscribing
this upper ring is to be a square frame of 7-inch wrought-iron
I beams, firmly secured thereto at the points of contact, and
also by means of the same sized beams at the angles. This
square frame, with the upper ring, radial beams and central
disc, all securely fastened together as described, form the turn-
table upon which rests the bridge. The towers, to the tops of
Report op City Engineer. 23
which are attached the cables or suspension rods that sustain a
portion of the weight of the bridge when swung open, are placed
directly over the ring which forms part of the turntable, and
exactly midway of the bridge longitudinally. These towers are
to be thirty-seven feet high, five feet by one and a quarter feet at
the base, and twelve inches square at the top. The corner posts
are to be 5-inch angle iron, connected either by plate iron or by
lattice bars. The towers are tied together and braced, across
the roadway, by three wrought-iron tubes or beams, of trian-
gular section, five-sixteenths inch thick and of nine-inch faces
attached at different levels, and connected together by vertical
struts of 6-inch I beams. In the bays thus formed are to be
diagonal rods, meeting in a ring at the centre, formed of bar
iron three inches by three-fourths inch. The cables or suspen-
sion rods, which transmit a portion of the weight of the bridge
to the towers, are three in number for each tower; the longest
one being two inches in diameter, the middle one, one and
three-fourths inches, and the shortest one, one and a half inches.
The construction of the bridge itself is the same as already
described in the case of the one hundred fieet span, except that
the spans being only about eighty feet, the crods-section of the
arches and chords is correspondingly reduced. The arches are
to be of the same height (ten feet).
Within the space formed by the circle of screw-piles, and
resting upon the lower set of radial beams, is to be a floor of
3-inch yellow pine, — the space to be enclosed and partitioned
ofi' to form apartments for an engine-room and a dwelling for
the draw tender; or iu lieu thereof, a suitable building is to be
erected on the fender pier.
Two caloric engines, of not less than three-horse power and
all necessary gearing for moving the bridge, to be furnished.
Also, a wrought-iron stairway, with steps of yellow pine, will
be built from the level of the roadway to the fender pier.
The fender-pier is to be two hundred and sixty feet long and
24 City Document. — No. 14.
sixty feet wide, and is to entirely enclose the draw-pier
witliout being" connected with it, thus preventing any shock
caused by passing vessels from being communicated to the draw-
pier. In construction, this fender-pier is quite a novelty, and
rather expensive as an experiment. It consists of three parallel
rows of tongued and grooved sheet-piling of 6-inch spruce or
pine, placed twenty-nine feet six inches apart from centre to
centre of each row — the rows being in the direction of the
thread of the current. Each row to be capped longitudinally
with a cap twelve inches square tenoned to the piles every five
feet, or oftener, if necessary. Cross timbers twelve inches
square and thirty-two feet long, lapping each other at the centre,
are to be bolted to the longitudinal caps and to each other at
the lap joint. These cross timbers are to be placed six feet
apart from centre to centre, and covered with a flooring of 3-
inch spruce or pine plank. Suitable belaying-posts are to be
bolted to the longitudinal caps, floor-timbers and sheet-piling,
and longitudinal oak ribbons three inches thick are to be
fastened to the channel side of the sheet-piling between low
water and the top of the pier. Fender-guards of oak piles or
sheet-piling are also to be built to protect the end piers of the
drawbridge, and to extend out from said piers to meet the
fender-guards which extend from the shore parallel with, and
eighteen feet outside of, the bridge.
From the pier at the northerly end of the drawbridge is to
be another bridge of one hundred feet span, precisely similar
to the one of the same span already described. But the pier
upon which its northerly end rests is composed of five screw-
piles arranged like those already described.
From this last mentioned pier to Lehigh street, a distance
of about two hundred feet, the structure rests upon wrought-
iron columns, and is identical in every respect with that on the
South Boston side already described.
The bridge over Lehigh street completes the list. It is of a
Report op City Engineer. 25
clear span of fifty feet, of the same style of construction as tho
one over Foundry street, is to be twelve feet in the clear above
Lehigh street, and its northerly end is to rest upon stone abut-
ments, built by the city.
Before work was commenced by the contractor, borings
■were made at various points on the entire line of the extension.
Eight borings were made on the South Boston side, which
showed that the surface of the clay bed underlying the mud was
about level with mean low water at Federal street, and thence
sloped downwards to the lowest point, which was on the easterly
side of Fort Point Channel, near tlie tracks of the 0. C. & N". R.
R. At this point the surface of the clay was twenty-four feet
below mean low water, in the centre of the channel it was eigh-
teen feet below mean low water, on the westerly side eight feet,
and thence to Lehigh street, it varied from eight to ten feet.
Two of the borings were sunk into the clay with a view of de-
termining its thickness and consistency at various depths. One
of these borings was made at the point where the clay bed was
most depressed. The total depth of this boring was ninety-five
feet from the surface of the ground, and the clay was penetrated
to a depth of fifty-five feet and was found to be of the very
finest quality, entirely free from stones, gravel or sand, and, in
point of consistency, appeared to be firmer and tougher near
the surface, than at a greater depth. The other deep boring
was made in the channel near the centre, and was carried down
to the rock, a depth of one hundred and eight feet below mean
low water, and through ninety feet of clay. The character of
the clay was much the same as in the last boring, and, so far as
the stability of the structures which are to rest on it are con-
cerned, it was evident that nothing would be gained by penetrat-
ing the clay more than eight or ten feet. In view of the clay
being softer than was anticipated, I suggested the addition of a
broad exterior flanch to the screw piles at a point eight or ten
feet above the screw-blade to form a bearing shoulder on the
26 CiiY Document. — No. 14.
surface of the clay when the piles were screwed into place. The
suggestion was approved and is being carried out.
PROGRESS or THE WORK.
The construction of the fender-pier in the centre of the chan-
nel has been a very slow and difficult job, as might have been
expected. It is, however, nearly completed. The screw-piles
for the draw-pier are all in position and ready to be sunk. The
iron columns on the South Boston side are nearly all set, and
some of the 12-inch iron floor-beams are in position. On the
Boston side, the pile foundations for the iron columns are all
driven. Most of the iron-work and lumber is on hand and ready
to set up as soon as the sub-structures are ready. The amount
paid to date is $174,388.
The Resident Superintendent of this work, on the part of the
City, is T. Willis Pratt, Esq.
ABUTMENTS AND RETAINING WALLS FOR [BROADWAY EX-
These comprise two abutments — one on the easterly side of
Foundry street, and one on the northwesterly side of Lehigh
street — and retaining walls on each side of the street from
said abutments, to Federal street on the South Boston side,
and to Albany street on the Boston side.
The abutments and retaining walls to rest on piles, cut off at
a level of seven and one-half feet above mean low water. The
abutments to be of such height as to permit the bridges above
described to rest thereon, at an elevation of twelve feet in the
clear above the roadways, and to be built of Quincy or Rock-
port granite, cut to dimensions, with rough-hammered beds,
builds and vertical joints. The retaining walls to be coursed
rubble masonry, laid in cement mortar, and suitably bonded,
the top surface to be built on an incline corresponding with the
grade of the street.
Report of City Engineer. 27
Proposals were duly iuvited, and the contract was made with
Messrs. Clapp & Ballou, in August, to furnish all materials
and do all the work on or before October 1st, at the following
rates for the various kinds of work,-viz :
For excavation, per cubic yard $0.85
For filling " " 1.00
For furnishing and putting ia ballast, per cubic yard, . 1.50
For furnishing and driving all piles, per pile . . 3.90
For furnishing and laying in cement all rubble masonry,
per cubic yard ....... 8.81
For furnishing and laying in cement all dimensioned
stone, per cubic yard 21.35
The work on the South Boston side has been completed. On
the Boston side the retaining walls are finished and a portion
of the abutment. The whole work will be finished, probably in
The amount paid contractors to date, as per my estimates, is
• The duties of the City Engineer in respect to this class of
structures remain the same under the present ordinance as
under the preceding one.
The following is a list of the bridges which the city has to
maintain in whole or in part : —
1st. bridges over tide-waters, riters and creeks.
* Albany street bridge, — over the Roxbury Canal.
* Dover street bridge, — across entrance to South Bay.
* Broadway bridge, — over Fort Point Channel (now building).
* Federal street bridge, — over Fort Point Channel.
* Mt. Washington avenue bridge, — over Fort Point Channel.
* Meridian street bridge, — over Chelsea Creek.
28 City Document. — No. 14.
* Chelsea street bridge, — over Chelsea Creek.
Winthrop bridge, — from Breed's Island to Winthrop.
* Ncponset bridge, — over Ncponset River.
* Granite bridge, — over Neponset River.
Milton bridge, — over Neponset River, at Lower Mills.
Mattapan bridge, — over Neponset River, at Upper Mills.
* Commercial street bridge, — over Creek at Commercial Point,
Mill Dam bridge, — over sluices connecting the " Fall Basin "
with Charles River.
Longwood avenue bridge, — over Longwood Creek and Brook-
line Branch Railroad.
2d. bridges over RAILROADS AND HIGHWAYS.
Albany street bridge, — over Boston and Albany Railroad.
Tremont street bridge, — (water pipes) Boston and Albany
Ferdinand street bridge, — over Boston and Albany Railroad.
Berkeley street bridge, — over Boston and Albany Railroad.
Columbus avenue bridge, — over Boston and Albany Railroad.
Dartmouth street bridge, — over Boston and Albany and Boston
and Providence Railroads, at junction.
Berkeley street bridge, — over Boston and Providence Railroad.
Dorchester street bridge, — over Old Colony and Newport Rail-
Broadway bridge, — one over Lehigh street ; one over Foundry
street (now building).
All the bridges marked with an asterisk in the first list, and
the Chelsea Point or Winthrop bridge are, or will be, when
completed, in the charge of superintendents under the direction
of the Committee on Bridges.
All the others, except the Tremont street water-pipe bridge,
* Bridges provided with draws or openings for the passage of vessels.
Report of City Engineer. 29
which is in the charge of the Water Board, are in the charge of
the Superintendent of Streets, under the direction of the Com-
mittee on Paving.
ALBANY STREET BRIDGE (OVER ROXBURY CANAL).
This bridge is a new one, and was completed and opened to
travel early in the year.
Plans and specifications were made last year by this depart-
ment, and a contract made with Joseph Ross, Esq., of Ipswich,
to build the structure for the sum of $7,450. It is provided
with a draw, of the kind known as a Counter-balanced Turn-
Table Draw. It has a roadway of thirty feet, a single sidewalk
of six feet on the westerly side ] and the opening for vessels is
thirty-four feet. Changes in construction, authorized by the
committee, increased the cost to $7,965.58. The estimated
cost was $8,000.
There has been expended in repairs on the bridge, replank-
ing, etc., $594.80.
The amount of travel over this bridge is very great, and con,
stantly increasing, and it seems highly improbable that the in-
significant requirements of navigation in this canal will much
longer make this bridge a necessity, and it will give way to
solid filling, and the full width of the street made available.
DOVER STREET BRIDGE.
A thorough examination of the draw of this bridge was made
last summer, and a report of its condition, accompanied with a
plan and specifications of changes and repairs, -which I deemed
necessary, was submitted to the Committee on Bridges, with the
recommendation that this bridge and the Mount Washington
avenue bridge should be put in thorough repair at once, so that,
upon the completion of Broadway, three good avenues would be
available while the necessary work contemplated on the Federal
street bridge should be in progress. That report is, 1 presume,
30 City Document. — No. 14.
on the files of the Committee on Bridges, and its recommenda-
tions should be carried out without delay.
An examination of other parts of this structure will be made
at an early day.
The repairs on this bridge during the year cost $834.14.
FEDERAL STREET BRIDGE.
The city of Boston was authorized to widen this bridge to a
width of seventy feet, by an act of the Legislature, approved
April 24, 1869.
Estimates were made of the cost of this widening, exclusive
of the drawbridge, which amounted to $19,000.00.
It was, however, subsequently deemed that such a widening,
leaving the drawbridge in its present narrow and contracted
condition, would be poor economy and of little public advantage.
The opinions of the Committees on Streets, Paving and Bridges,
favored the making of the drawbridge of the full width of
seventy feet, with the roadway clear and unobstructed by any
middle truss, and this department was called upon to devise a
plan for the draw, which would fulfil these conditions, without
materially altering the present bridge beyond what would be
necessary to provide room for the enlarged draw. Accordingly
levels were taken, and measurements made to determine the
amount of available room beneath the roadway for depth of
girders, wheels, etc., without raising the grade of the street ;
and also to locate the present piling to see how much would be
available for the new structure, and the additional amount that
would be required. Progress upon this work was necessarily
interrupted by the current demands upon the department from
work already in progress, and was suspended entirely for a
season, while the surveys, plans and specifications for the Dart-
mouth street bridge were being prepared.
The problem presented by the requirements of tiie committees
was more difl&cult of solution than at first appeared. It was
Report of City Engineer. 31
not simply to decide upon the best style of draw, but upon the
best style that could be fitted to the place, and at the same time
satisfy the requirements of the committee and the demands of a
judicious economy. If an entirely new structure were to be
built and no restrictions as to grade, it need not require a very
long time to perfect designs and specifications ; although, in that
case, there would be room for considerable debate as to which
of the various styles of drawbridges now in use would be best
adapted to the unusual width of roadway demanded in this case,
and the oblique angle which the opening for the passage of ves-
sels makes with the axis of the bridge. If the bridge could be
placed at a proper elevation, there would be no question but
that permanent foundations and a substantial iron structure
would be the most suitable, and, in the end, most economical.
But, with all our present bridges, the grade is so low that the
tracks and running gear have to be placed below extreme high
water mark, and no little trouble and inconvenience ensues.
The superintendents have complained of the low grade of the
draw-piers, and the necessarily contracted space beneath the
bridges into which the machinery is crowded. Of course, the
greatly enlarged dimensions of the drawbridge in the present
case called for additional depth or space between the surface of
the roadway and the top of the draw-pier, which could only be
obtained by raising the grade of the roadway or still further de-
pressing the draw-pier.
Under these circumstances, I felt that the expense of perma-
nent foundations and an iron superstructure, as an adjunct of
the present patched-up bridge and at its present grade, would
be quite unwarrantable.
Accordingly, designs were prepared of several styles of
draws, to be built of wood, which, it was thought, would outlast
the present wooden structure. At this stage the policy of the
Harbor Commissioners, as announced in the case of the Broad-
way bridge, rendered it certain that additional requirements
32 Cixr Document. — No. 14.
would be made in this case, and that, besides the widening of
the roadway of the bridge, the span would also have to be in-
creased so as to make the opening for the passage of vessels
forty-four feet in the clear. It therefore became necessary to
make a new series of calculations of strains to determine the
new proportions and dimensions of parts, and to reconstruct the
designs. The designs, which have been made, include several
styles of draw, or modifications of styles already in use, such as
the " Counter-balanced Turn-table '' ; a " Centre Pivot," without
turn-table, — the draw travelling upon attached wheels — a
"Side Pivot," with wheels attached, and a" Slide " or " Rolling
Draw," like the present. The " Centre Pivot " design would
require a middle truss, and would probably be the least expen-
sive, although no definite estimates have been made.
After the Broadway bridge contract was made, and it became
certain that within a year this addidional avenue to South Bos-
ton would be opened, the necessity for pressing this work be-
came less urgent, and a majority of the Bridge Committee
favored its postponement until the completion of Broadway. For
this reason, and on account of the demands of other work, very
little has since been done on the work by this department, ex-
cept preparing a plan exhibiting the present pile foundations,
with the proposed additions, to present to the Harbor Commis-
sioners for their opinions and views ; for it would be useless to
spend further time upon the details of any plan unless the com-
missioners will approve of the necessary foundations. Some addi-
tional drawings have, however, been recently made to illustrate
the application of a plan proposed by a Mr. Rich, of South Boston,
to this particular locality. The general features of this plan
were exhibited in a model, and, as applied to this locality, may be
thus described : — The present draw is to remain just as it is, and
a turnout bridge, wide enough for two lines of vehicles to pass
each otlier, is to bo built in an easterly direction alongside the
present pathway of the vessels approaching the draw, for a dis-
Report of City Engineer. 33
tance of about two hundred feet, or far enough to permit a ves-
sel to lay between the present draw and the easterly end of the
" turnout," where another draw is to be built, connecting with a
similar turnout on the opposite side of the shipway. At the en-
trance to the turnouts, gates are so arranged that when the
present draw is open for the passage of vessels, its guard gate
is closed and the turnout gate is open. By this plan it is
claimed there will be no detention of travel, as only one draw
will be open at a time. The idea is not a new one by any
means, although the particular mode of its application is novel.
In this instance, it involves the building of about five hundred
feet of bridge, including an extra draw. It could be applied to
this bridge in connection with the proposed widening, without
any interruption to the travel ; and it is claimed that the com-
bined cost of widening the present bridge to seventy feet, exclu-
sive of the draw, and building the " Turnout bridge " and draw,
will be from ten to twelve thousand dollars cheaper than the
proposed plan of widening the present bridge, including the
draw ; and that the '' Turnout " plan will better accommodate
The various plans will soon be laid before the Committee on
The cost of repairs on this bridge during the past year was
MOUNT WASHINGTON AVENUE BRIDGE.
This bridge was examined early in the season, and found in
a most wretched condition throughout.
The wooden trusses of the drawbridge were in an unsafe
condition, the chords being badly decayed, and in one place the
lower chord was rotted entirely through. The stringers and
timbers which form the sidewalk bulkhead were very rotten,
and the flooring of the bridge in bad condition. In short, the
whole bridge is in such condition as to require almost an entire
34 City Document. — No. 14.
renewal above the caps of the piles, or at least, above the
stringers. At that time it was thought that the widening of the
Federal street bridge must be taken hold of, and, as both could
not go on together, this was repaired as well as possible, and
the trusses strengthened so as to make it last until another year.
When it became apparent that the work on. Federal street
bridge would be postponed until the completion of Broadway,
I again called the attention of the committee to this bridge, in
the report above alluded to, in connection with the Dover street
bridge. No action, however, appears to have been taken. I
consider this bridge in a very bad condition, and should be
attended to at once.
The amount expended for repairs on this bridge during the
year was $2,486.52.
MERIDIAN STREET BRIDGE.
This bridge, exclusive of the draw, is in very good condition.
The draw itself, as to soundness and stability, is in good condi-
tion ; but it does not work as easily as it should. The track
was levelled up, new white oak bearing-plank put in, and
wrought-iron plates interposed between the track-rail and the
oak bearing-plank, in 1868; but owing to the work not having
been properly done, or for some other reason, it did not entirely
remedy the evil. The draw is a cumbrous, unwieldy affair,
and its foundations not the best, and it would undoubtedly have
been better policy to have built it anew, upon more substantial
foundations, at the time the bridge was rebuilt, in 1866. A
smaller and lighter draw would answer every purpose in this
The repairs on this bridge during the year have cost $842.58.
CHELSEA STREET BRIDGE.
This bridge was partially renewed in 1868. At that time
plans and specifications were prepared by this department for
Report op City Engineer. 35
rebuilding the entire structure, whicli I deemed the wisest
course. The committee, however, thought differently, so the
specifications were redrawn to cover the building of a new
draw and certain prescribed repairs, and a contract made with
Joseph Ross for doing the work for tiie sum of $6,150. It was
found, however, upon removing the earth covering of the bridge,
that the entire flooring was so much decayed as to be unsafe.
A new flooring was accordingly ordered by the committee,
which was put in by Mr. Ross. The total cost was $9,146.35.
The bridge is now in very good condition. The repairs
during the year amounted to $42.
WINTHROP BRIDGE (BREED'S ISLAND TO WINTHROP).
Tills bridge has no draw, and the travel over it is very light .
The bulkhead stringers need renewal in some places, and an ex-
amination of the flooring, which will be made in the spring, will
undoubtedly discover many defects now concealed by the earth
NEPONSET BRIDGE (OVER NEPONSET RIVER).
This Bridge was formerly a toll-bridge belonging to the Turn-
pike Corporation, and since it was made free has been maintained
jointly by the towns of Dorchester and Quincy. Its condition
is reported good by the authorities of Dorchester ; but an exam-
ination will soon be made and its condition reported to the
Committee on Bridges.
GRANITE BRIDGE (OVER NEPONSET RIVER).
This bridge is " Granite " only in name, which is derived from
the street of which it forms a part. It is a pile structure, pro-
vided with a drawbridge of the old style known as tlie " Leaf-
Draw." It is in very fair condition; but will require some
repairs on the planking of the roadway. The city maintains
the bridge to the centre of the draw.
36 City Document. — No. 14.
MILTON BRIDGE (OVER NEPONSET RIVER AT LOWER MILLS).
This is a substantial stone bridge, in good condition, with
new railings ; but is rather too narrow, and a widening to cor-
respond with the width of roadway on the Milton side would
be a great improvement. It is maintained jointly by the city
and the town of Milton.
MATTAPAN BRIDGE (OVER NEPONSET RIVER).
This bridge is a light iron structure, recently erected and in
good condition. The web of the main girders is very thin, and
lower chord too light for the standard of burden usually re-
quired in our city bridges. It is maintained jointly by the city
and the town of Milton.
COMMERCIAL STREET BRIDGE (OVER CREEK AT COMMER-
This is a pile structure, provided with a " Leaf-Draw." The
draw, draw-pier, and northerly end of the bridge are in good
order. The southerly end of the bridge is quite "shaky," —
the bulkhead stringers are rotten, and the piling needs renewal.
The flooring is covered with earth, and is probably more or less
decayed, and should be examined soon.
MILL-DAM BRIDGE (OVER SLUICES).
These sluices or water-ways through the Mill-dam were origi-
nally provided with tide-gates, which permitted the water to
flow into the " full basin," so-called, duriug flood-tide, but closed
at the ebb and shut the water in. After the abandonment of
the tide-mills, caused by the filling of the " empty basin," these
gates were removed and the tide now ebbs and flows through the
sluices. They are openings or water-ways, six in number, about
twenty feet wide, and separated from each other by stone piers
about five feet thick, built up to within four feet of the roadway.
The sluices are then covered with round logs laid close together,
Report op City Engineer. 37
the ends resting on these piers, and upon the logs is the earth
covering of the roadway. These logs are more or less rotten
and insecure, and the question has arisen — " With what shall
they be replaced ? "
These sluices will have to remain open for many years, cer-
tainly as long as this basin remains unfilled; for into this basin
flows all the drainage of " Stony " and " Muddy " brooks, and
until the basin is filled and very large covered canals provided
for conveying this drainage to tide water in Charles River, the
maintenance of these sluices will be a necessity.
Plans have been prepared, by request of the Paving Depart-
ment, for covering these sluices in a safer and more substantial
manner, with either a wooden or iron structure, whichever shall
be decided most suitable under all the circumstances. Specifi-
cations will be drawn as soon as the committee determine which
plan to adopt.
LONGWOOD AVENUE BRIDGE.
This bridge crosses " Muddy Brook " (the centre of which
forms the boundary line between Boston and Brookline), the
adjacent marsh flats and the Brookline Branch Railroad. It is
a trestle-work structure, resting on oak piles, has a plank road-
way, and a sidewalk, on the southerly side only, and is not a
suitable structure for the locality. The abutments are poorly
built, and in bad condition. The care and maintenance of the
structure belongs to Boston and Brookline jointly. By orders
from the Paving Department, — to prepare plans and specifica-
tions for a suitable structure, with proper abutments, — consid-
erable work has been done in making surveys, levels and
soundings, and preparing the necessary plans. The plans in
detail will soon be ready to submit to the Committee on Paving,
and the Selectmen of Brookline.
ALBANY STREET BRIDGE (OVER BOSTON & ALBANY R. R.)
This bridge was built in 1867-8, by JklcKay and Aldus, from
designs by Clemens Herschell, C. E. The entire cost of the
38 City Document. — No. 14.
bridge, abutments, and rctainiug walls, was $65,973.22. The
structure is in good order.
HARRISON AVENUE AND WASHINGTON STREET BRIDGES.
These bridges are maintained by tlie Boston and Albany
Railroad Co. ; but by an agreement with the city, by which the
corporation was permitted to raise these bridges, the plans of
reconstruction were to be approved by the City Engineer. Ac-
cordingly plans for new iron bridges, designed by E. S. Phil-
brick, C. E., were submitted to me, and carefully examined in
all respects as to their strength and stability, and approved.
The Harrison avenue bridge has since been buiit, and is a first-
class specimen of iron work. The Washington street bridge
will probably be built this season, in connection with the raising
of the Suffolk Street District.
FERDINAND STREET BRIDGE (OVER BOSTON & ALBANY R. R.)
This bridge lias been lowered during the year, by permission
of the Boston and Albany Railroad Corporation, improving very
materially the grades of the adjacent streets. It is in good
BERKELEY STREET BRIDGE (OVER BOSTON & ALBANY R. R.).
This bridge was built for the Boston Water Power Company
by the " Moscley Iron Bridge Works." It is probably as good
a bridge as could have been built for the money it cost ; but it
is a lighter and cheaper structure than I should have recom-
mended. It has, however, been quite well tested during the
past year while Treraont street was closed, and a recent exam-
ination disclosed no perceptible deflection or permanent set to
the girders as compared wiih an examination made last spring.
The present mode of planking the roadway on a dead level,
is objectionable, as there is no provision for shedding the rain-
fall. A substantial Burnettized bottom flooring should be laid
Report op City Engineer. 39
and covered with asplialtum concrete so as to give a longitu-
dinal crown to the roadway, and upon this a pavement of
•wooden blocks should be laid. The iron work should be
BERKELEY STREET BRIDGE (OVER BOSTON & PROVIDENCE
This structure was built by the Boston & Providence Rail-
road Company, and was accepted as a part of Berkeley street
last year. The roadway and sidewalks are supported upon
very heavy cast-iron columns, placed in rows crosswise the
street, the rows being about twenty feet apart. The columns
rest upon a pile foundation, capped with granite blocks. Upon
these columns heavy wrought-iron Phoenix I beams or girders
are laid crosswise the roadway, and upon these, similar longi-
tudinal floor-beams are placed about four feet apart. The floor-
ing, as originally built, consisted of spruce plank laid flatwise
and fitted between the floor-beams, re&ting on the lower flanch.
The space above the plank was filled with gravel to the level
of the tops of the floor-beams, and directly upon the gravel was
placed the wooden block pavement. As might have been ex-
pected, the gravel covering rotted the plank; a portion of the
wooden blocks also rotted at the bottom and settled unevenly,
causing the surface of the roadway to present a very rough ap-
pearance. Under these circumstances it is not surprising that
the heavy travel of last summer broke through the planking and
revealed its rotten condition.
This department was immediately called upon to prepare
plans for re-covering the bridge, and the following general plan
was proposed. To strip the bridge to the iron work, then to
fit between the longitudinal iron girders 4-inch spruce plank
floor-beams, set edgewise, and resting upon the lower flanch of
the girders ; these planks to be placed three feet apart from
centre to centre and to be of gi-aduatcd widths, — from twelve
40 City Document. — No. 14.
to eight inches, — the widest being placed in the centre of the
roadway and thence diminishing in width to the gutters, forming
a lateral crown to tlic roadway. Upon these plank floor-beams
a flooring of 4-inch spruce planij, planed to an even thickness, to
be laid diagonally of the roadway and thoroughly spiked. The
Nicholson block pavement to be laid on this flooring. The curb
or wheel-guard to be of cast-iron. The sidewalk to be replanked
with 3-inch plank laid close and covered with asphaltum con-
The lumber was to be one-half Burnettized and one-half cre-
osoted, to test its relative merits. The proposed plan as above
described was carried out.
Upon uncovering the bridge it was discovered that some of
the iron columns had either settled or were not properly levelled
when set, and that it would be necessary to level up the whole
structure. The Providence Railroad Company desired that the
whole bridge should be raised a foot, and ofi"ered to bear the
expense of raising, and as this operation would enable us to re-
adjust the columns at their proper relative height it was decided
to raise the whole bridge an average height of twelve inches.
The execution of the entire work was intrusted to Joseph Ross,
Esq., and it was promptly and successfully accomplished.
The bridge, with all its travel, was lifted bodily by screws
attached to each column. Every column had marked upon it
the exact height it was to be raised, and a granite leveller was
provided for each column, whose thickness corresponded with
the mark upon the column. Tiie work was all done without
any interruption to the public travel.
The cost of the work was $16,124.18.
COLUMBUS AVENUE BRIDGE (OVER BOSTON & ALBANY R. R.).
This bridge was built in 1865 from designs by Clemens
Herschell, Civil Engineer for the Boston Water Power Com-
pany. It is a wrought-iron lattice bridge of very good design
Report of City Engineer. 41
as to strength and stiffness ; but not a remarkably good speci-
men of workmanship. By the laying out of Columbus avenue,
June 24, 1869, the care and maintenance of this bridge and
abutments was assumed by the city. Its condition is fair, but
similar measures to those proposed for the Berkeley street
bridge should be taken here to crown the surface of the road-
way so as to shed the rainfall.
DAKTMOUTH STREET BRIDGE (OVER B. & A. AND B. & P. R. R.).
This department was called upon to furnish plans and esti-
mates for a bridge over the Boston and Albany and the Boston
and Providence Railroads, at their junction. Approximate
estimates were furnished of the cost of a substantial iron
bridge, with suitable abutments and piers, and some progress
made in the preparation of drawings in detail ; but it was de-
cided that there was not ample time to prepare, decide upon
and execute plans for such a structure in season for the " Peace
Jubilee " ; and it was also thought that a well-built wooden
structure would answer all the public requirements for ten or
fifteen years, and could be built for less than half the money.
Accordingly, plans and specifications were at once prepared for
a wooden trussed bridge.
The abutments and intermediate piers consist of oak piling
and heavy trestle-work. The two main trusses, which are built
continuous over the piers, are respectively two hundred and
twenty and one hundred and ninety-eight feet long, and of the
style known as the " Pratt Truss." The lower chord is formed
of four pieces each six by twenty-four inches ; the upper chord
has four pieces, each six by ten inches ; the posts or struts are
each six by twenty-four inches, except over bearings, where they
are twelve by twenty-four inches. All counter-rods are single
and one and one quarter inches in diameter, and the others are
in sets of two and three, and vary from one and thi-ee-fourths
42 City Document. — No. 14.
inches diameter at the bearings to one inch at the centre of the
The sidewalk trusses rest on the same piers as the main
trusses ; but as the piers are necessarily at an angle oblique to
the axis of the bridge, the lengths of tlie spans vary. They are
continuous over piers.
The lower chords consist of three pieces: the centre one,
six by twelve inches ; the two outer ones, four by twelve inches.
The upper chord has three pieces : the middle one, six by eight
inches, and the outside ones, three by eight inches ; the struts
over bearings are eight by twelve inches, and the intermediates,
four by twelve inches.
The counter rods are single and one inch in diameter ; all
the others are double and one inch diameter at the centre of
spans, and increase one-eighth of an inch for each bay to the
The trusses are eight feet in height from outside to out-
The floor-timbers are four by fourteen inches, placed two in
each bay or panel ; every other one is double and trussed with a
truss-rod one and one-fourth inch diameter, the struts being
continuous twelve by twelve inch timbers running the whole
length of the bridge.
The roadway floor is double, the lower one being of 4-inch
spruce, and the upper one 2-inch white oak, laid crosswise the
The sidewalk floor is of two thicknesses of 2-inch spruce
The trusses are covered with a wooden coping, and all the
woodwork and ironwork exposed, was painted three coats and
All the woodwork was creosoted or Burnettized.
Proposals were invited, and the contract awarded to Joseph
OSS, of Ipswich.
■ Report of City Engineer. 43
Although not entirely completed by Jubilee week, yet the
roadway was finished and the bridge pretty severely tested by
the moving crowds.
The bridge is a first-class piece of work, and as substantial
as could be made of wood. The cost was $26,780.
DORCHESTER STREET BRIDGE (OVER OLD COLONY AND NEW-
PORT R. R.).
The bridge over the Old Colony and Newport Railroad at
this place was originally built, and has since been maintained,
by the Railroad Company. In order to complete the widening
of the street it was necessary to enlarge this bridge, extend the
abutments, and build new retaining walls. So far as the alter-
ation of the bridge and abutments were concerned, the city was
powerless to act without the consent of the Railroad Company.
Therefore an agreement was concluded between said company
and the city, by which the city was to do all the work required,
and assume the care and maintenance of the bridge and abut-
ments ever after, the Railroad Company paying four-fifths of
Plans and specifications were prepared, for all the work
required, last March. Proposals were invited, and contracts
awarded, to the Atlantic Works for building the bridge ; and to
Messrs. Clapp and Ballon for the masonry, grading and filling.
The old bridge was a wooden one, and could not be econom-
ically widened, and a structure, mainly of iron, was recom-
mended. The width of 'the street, as widened, is fifty feet, and
the clear span of the bridge twenty-seven feet. The bridge
consists of seven parallel wrought-iron plate-girders, thirty feet
in length, twenty-two inches high in the centre, and seventeen
inches high at the ends, placed eight feet six inches apart from
centre to centre, under the roadway, and eight feet under the
sidewalks, — all tied together at the bottoms with two-inch
angle iron Oak stringers of 4-inch plank are placed edge-
44 City Document. — No. 14.
wise on the lower flanches of the girders, and bolted to the
webs. Upon these stringers floor-timbers of four by twelve
inch creosoted spruce are placed at right angles with the girders,
and three feet apart from centre to centre. An under flooring
of 4-inch creosoted spruce plank is laid upon these floor-tim-
bers, the top surface being just flush with the tops of the
girders, and over this an upper floor of 3-inch white oak plank
is laid at right angles, or crosswise the roadway. The outer
roadway girders support a cast-iron wheel-guard or curb, pro-
vided with flanches and sockets on its sidewalk face for
receiving one end of each of the sidewalk floor-timbers, — the
other end resting upon an angle-iron flanch, riveted to the web
of the sidewalk girder. The sidewalk floor is of 2-inch spruce
The railing is composed of cast-iron posts riveted to the
sidewalk girders, and horizontal rails of wrought-iron pipe
fitted to posts by a right and left screw.
Beneath the sidewalk, and not connected with the bridge, are
a pair of wrought-iron plate girders, sixteen inches deep and
twenty inches apart, with cast-iron cradles fitted between and
bolted to the web-plates, to support a 12-inch water pipe. All
the work under both contracts has been done, and the cost of
the bridge work was $3,000, and of the mason work, grading
and filling, $8,250.
D STKEET EXTENSION BRIDGE — ABUTMENTS AND WALLS.
Estimates for the Committee on Laying out and Widening
Streets have been made of the probable cost of an iron bridge,
the necessary abutments and retaining walls, that would be
required if the extension of D street, from its present terminus
to Federal street, were made at the high grade, crossing the
Old Colony and Newport Railroad fourteen feet in the clear
above the tracks.
Report op City Engineer. 45
shawmut avenue extension and indiana place
Surveys, levels and soundings have been made, and plans
partly finished for the structures that would be required by the
extension of Shawmut avenue over the Boston and Albany
Railroad, the raising of the grade of Indiana place and of
Castle street. Preliminary estimates have been made for the
Committee on the Suffolk Street District, of the cost of these
N. HENRY CRAFTS,
BOSTON PUBLIC LIBRARY
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