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Full text of "Electrification of the Baltimore and Ohio tunnels in Baltimore."

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KLECTKlFiUATlOU OF 1'MJi BALTIMORE AND OHiO TUNNELS IN 

BALTIMORE 



BiBLlOURAPHY,- 

General Electric Review- 
Reprint from is3'j.e of Oct. I92JL 

Genaral Electric Review- 
issue of Dec. i9iO. 

Railroad Electrif ication- 
By Hanson . 

Electric Railway Engineering- 
Bv Par shall and Ho bar t. 



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ELECTRIFICATION OF THE BALTIMORE AND OHIO TUNNELS 

IN BALTIMORE 

A PIONEER PROJECT.- The history of the electri- 
fication of the Baltimore ar-d Ohio tunnels at Baltimore is 
of importance because it was the first application of 
electricity as a motive power on a trunk line. with 
no predecessors to lead the way and necessity demanding it, 
tcie Baltimore and Ohio Railroad went ahead and performed 
this engineering task and made it a success, thus paving the 
way for others and bringing the railroad up to a higher 
level of efficiency and service. Working if conjunction 
with the.r, was the General Electric Companv, which supplied 
there, with electrical equipment. it is partly due to this 
company that the electrification was so well planned and 
executed. Si-ce that time rranv railroads have resorted to 
electrification, to abate the smoke nuisance, relieve main- 
line congestion, conserve fuel and otherwise lower operating 
costs , 

UAjSE OF ELECTRIFICATION.- The B&O tunnels at 
Baltimore consist of a .uain tunnel called the Howard Street 
Tunnel and a series of smaller ones. Previous to their 
electrification, it was necessary to ferry the trains across 
an arm of the Patapsco River instead of tnnnirg them thru 
the city. There were two reasons for this: first, an 
ordinance of Baltimore governing- the construction of the 

line thru the citv re uired that the trains be operated 



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electrically inside the city limits a^d ^eco^dlv, 
the num <er and length of the tunnels was too great for 
steam locomotive? to operate in their, due to difficulties 
in removing the gas and smoke frorr them. Such were the 
conditions when the 3&0 decided to electrify the tunnels. 

DESCRIPTION OF THE iLECTFUFlED ZONE.- The BaG 
electrified a section 3.75 miles in length, it included 
all the tunnels and was located wholly within the city. 
The aone extended from Camden Station on the west to 
Waverlv interlocking Tower on the east. This space is 
occupied by the eight tunnels to the extent of 43^ of the 
total length. The lorgest tunnel has a length of 76W 
feet. The trap shows the location and length of the tunnel - 
which are numbered in order that they mav be readily found 
or the profile chart. As may be seen, the entire section has 
two tracks except that part which lies between Mt . Roval aid 
Hunting to i: Ave. This place has four tracks making the 
total length of track anout 3 miles long. The profile 
shows that the entire section is upgrade from west to east. 

THE SERVICE.- On Jure 37,1894, the first trial 
trip was made although regular operation was not b»gun 
until May i,i895. The equipment consisted of 3 96- ton 
gearless locomotives, designated as clasp LE-j., wbicn 
handled the east bound upgrade trains. As the downgrade 
to the west is rather stsap, ro electric hauling was done 
in that direction; the steam locomotives handling their 
own trains down the grade. This method has '->een used up 
to the present without any great difficulty. This service 



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MAP, TRACK CHART AND PROFILE OF THE ELECTRIFIED 
TUNNEL ZONE AT BALTIMORE 



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differs from the so called "helper service" in that the 
electric locomotive receive? no aid from the pteaff engine 
■A-hose load it in pulling. in other words, when a train 
arrives at the west end of the electrified zone, tno 
electric locomotive attaches itself to the steam locomotive 
ar.d its train and drags them up the grade thru the tunnels. 
Due to the grade in this zone, the electric engines must 
develops appro ximately twice the tractive effort that the 
steam locomotives, which they drag thru the tunnels, 
develops in running from Baltimore t© Philadelphia. 
Although the wsst-bsund trains operate thru the tunnels 
under their owr power, electric assistance is given to 
start then:. Under these conditions, the electric loco- 
motive returns, after each haul, without a load. 

THE ORIGINAL POWER SYSTEM.- At that time all the 
power was supplied to the line directly frorr five generators 
at the west end of the electrified section. The power 
station was built especially to supply electricity to the 
zone under discuspio r ' and co^pi^ted of five 500- K." . 700 
volt direct current generators which were direct-connected 
to tardem esmpsund non-condensing Corliss engines. These 
were the largest direct-connected generators then in use. 
in order to reduce the cost of operation and improve the 
voltage on the line, a storage battery substation was 
erected, at a later date, near Mt . Royal; a distance of one 
and three-quarters miles from the power house. The 
generated or bus-bar voltage was lowered to 500 volts so 



that the excess current ccrald "•! used for industrial 
purposes. This made necessary the use of a rooster zyttea. 
of control to give the locomotives sufficient power for 
efficient operation during the period of peak load. The 
power available for the train service was limited to 900 
kilowatts by the capacity of the booster set. i'his 
maximum power was sufficient to handle one freight train of 
i,i00 tons weight and a light passenger train. A overhead 
distribution svstem was used. The contact conductor was 
toad* by placing two Z bars together to form a ->ox-like 
structure with a slot in the bottom. Thie was supported 
in the tunnels by direct current hangers ard outside of 
outside of them by towers and cater ery supports. A 
collector shoe was mounted upon a pa^to^ranh a^d allowed to 
slide in the slot of the conductor. This tvpe proved to 
b« very defective due to the actio r of the gases in the 
tunnel upon the metal at the point of contact and 
consequently was replaced at a later date iy a third rail 
system. 

CLASS LE-i LOCOMOTIVE USED.- The first electric 
locomotives used in this zone were of a design tnat 
followed the common locomotive practice in the united 
States. The B&O was supplied with three of them by the 
General Electric Company. Each was capable of hauling a 
2,500-ton freight train at a speed of tea miles per hour, 
a i, 800-ton train at twelve ^ilee per h^r or a 500- ton 
train at thirty-five miles per h:>ur. They were the 



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heaviest locomotives built for electric service in trie 
world at that time; each weighing 37 metric tons. They 
were rated at 360 horse power at 300 volts and had a total 
tractive effort at full load of 2,800 pounds although their 
starting tractive effort was 4,800 pounds. it is interest- 
ing to note that> in spite of their great wight, they were 
only one-third as powerful as those used on the New York 
central Railroad. 

CONSTRUCTION OF THE CLASS LE-i LOCOMOTIVE.- The 
iruck of this tvpe of loco votive was built up of wrought 
iron bare welded together to form a trussed f ra- e -.fnicn 
rested on four wheel?, and carried two gear less to tors. 
Two of these trucks, were ccjplea together Eo form the under 
frame of the locomotive. The motors were of the General 
klectric t7pe A X B 70 railway motor. The armature was 
spring-suspended upon a auill surrounding the axle. A 
spring- supported field was centered upon this -mill oy 
means of oearings. The power was transmitted from the :-.otor 
to the wheels by the use of a sprocket and rubber driving 
cushions, thus eliminating gears entirely. Since that time 
many types of geared electric "-rotors have bee-" developed but 
the good qualities of this type are shown ty the fact that 
at present gearless motors are used for passenger service on 
the Coast Division of the Chicage, Milwaukee and St. Paul 
Railroad. The principle differerce in the rrotors is that 
the former are operated or a lower voltage than the latter. 
CLASS LE-2 L0C0M0T1VF.- in 1903, the ^&0 heuffht 



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two new two unit locomotives frort- cue General electric Go. 
for use in the tunnels at Baltimore. They were known as 
Class LE-2 . Each weighed i45 tons or 73 tons per unit 
and developed ^600 horse power since they were trade in two 
sections having 4-S00 horse power motors per section. it 
was required that each two unit locomotive should handle a 
train of a weight of 1,450 metric tons In addition to the 
■ft eight of the locomotive itself on the B&O trunk line thru 
trie tunnels over a 1.5% grade at a speed of 9 miles per 
hour on a 625 -volt circuit. This performance reauired a 
a tractive force of 92,000 pounds per motor. 

CONSTRUCTION OF THE CLASS LE-3 LOCOMOTIVE.- The 
cab was of the box type, having two pets of controls located 
in diagonally opposite comers of each cab. Glas doors ai a 
large glas? windows permitted the operator to wee in all 
directions from within the cao. There wa" ample apace under 
the can floor to inspect the motors and truck gear. The 
motors were operated thru a multiple unit control system, 
so arranged that each section might ~e operated independently 
or in con^uncxion with two or more sections coupled together. 
Fonr heavy pieces of cast steel, two side fran-.es and two end 
pieces, forced the main body of the truck. Strength and 
rigidity was obtained hy machining the parts at the e-ds 
where they were fitted together. The ends of the frame? 
were used as buffer Teams. To theT wap attached draft gear 
which was capable of withstanding a tractive force of 
100,000 pounds. This gear was so designed as to allow both 



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lateral ard lor.gir.tudir.al motion. The truck frame was 
supported by eiualisers at four points. The equalizers 
rested on half -elliptic springs, the ends ofwhicb rested on 
journal boxes. The constriction of the brasses mas such 
that the? Tight be readily removed without mowing the 
wheels and axles or other parte of the truck. The motors 
were of the General Electric tvpe 65 B, developing 200 
horse power at 325 volts. They were geared to the driving 
wheels with a 8i/i9 ratio. The eight motor? supplied the 
power thru sixteen driving wheels. 

THE THIRD RAIL SYSTEM INSTALLED.- in l9Q3, the 
third rail system was installed. Most of the original 
installation is still in use, although, after ten years of 
service, it was necessary to renew the third rail in the 
Howard Street Tunnel due to the effect of loeo^-otiv? gases 
and electrolysis upon it. A new type of insulator ard board 
support was used to improve the third rail system in this 
tunnel. 

CHANGE IN SOURCE OF POWER.- The demand upon the 
electric service grew so rapidly that, in 1909, the great 
weight and number of trains "-ade it neOftssarv to i^creape 
the electric power capacity of the system. A complete 
charge in the method and location of power generation was 
made. The railroad decided to buy their power from the 
Con. Gas, Electric Light ard Rower Company. Since this 
po.'.er was in the form of three phase, 13,000 volt, £5 cycle 
current, a rotary converter substation was necessary to 



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supply the line with direct current, A rotary converter 
substation was consequently constructed at Mt . Roval Inwhich 
S-iOOO K.W., S50 volt svncronous converters with auxiliaries 
were installed. The ouildmg w-s made of -uch size that 
additional converters could he added whenever it -ecame 
necessary to increase the capacity of the plant. me 
battery unit was retailed to aid ecoro-ical service at peak 
load. After the Mt . Royal ~u -station went into operation, 
the power plant that had been used up to this time to supply 
the total power was neither necessary nor desiraole so it 
was dismantled. 

CLASS OE-i LOCOMOTIVE.- Another addition was 
made to the locomotive equipment in i9iO when the railroad 
secured two new electric locomotives of the Detroit Tun~el 
type. They were made by the General Electric Company 
working in conjuration witn the American Locomotive Company 
and consist of a main cab with a sloping auxiliary can on 
e&ch end. Their design is such as to ^ake thenn worthy of 
a detailed study. 

MECHANICAL CONSTRUCTION OF THE OE-i.- This 
locomotive was built for great weight and strength. The 
runnung gear is formed by two four wheel trucks connected 
together thru a massive hinge which allows lateral moticn 
although the trucks support and guide eajh other. Great 
weight was tne ruling factor in designing the framing; the 
side pieces consisting of steel castings five inches thick, 
which were olted together thru steel end frames a ,_, d oolster 



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to form the fra- e structure are a proof of tM^. The 
draft gear and buffer? were carried on both ends. The 
wheels are steel tired and fifty inches in diameter, having 
gears mounted near their hu^s. The weignt of the locomotive 
is carried on cast steel journal boxes whicn are mount ed on 
pedistal jaws oetween nine inch shoes. The weight is 
carried to the ooxee thru semi-elliptic journal box springs 
designed to give as uniform a distrioution of weight as 
possiole over groups of springs. This construction 
relieves the platform and cab of most of the operating 
stresses , 

ARRANG&MLNT OF APPARATUS.- The main air reservoir 
is located well ud in the end of the auxiliary cab. Behind 
this in order named is the sander for the forward wheels, a 
set of rheostats and the contactors. Perforated side 
sheets provide ventilation for the rheostats. The Contactors 
are banked facing the main cab and are available from it, 
Ordinarily asnestos lined doors shut the'-' off from the main 
cab. This auxiliary cab is so constructed that in can be 
rert',oved as a unit from the locomotive. In the main cao 
d,re the sand ^oxes on the sides and the air compressor i 
a central position. This compressor has a capacity of 
100 en . ft, of air per minute when pumping against a pressure 

of liO pounds. in going from the low pressure to the hi^h 
pressure cylinder, the air passes thru 35 feet of 2 inch 
pipe on the roof to cool it. it is cooled in a like manner 
in passing from the high pressure cylinder to tne reservoir. 



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A blower unit nest to the compressor supplies the motors 
with forced ventilation. The control apparatus is 
provided in duplicate at each end of the ca\ it is 
located at each end of the cab in the right hard corner 
ard consists of the master controller, air brake valves, 
air gauges and ammeters. The handles for the sell and 
whistle ropes, the switches for headlights and valves for 
sanders are within reach of the operator. 

MOTOR EQUIPMENT OF THE OE-l.- This locomotive 
has four motors designated a= G.E.209. They are of the 
six pole commutafcing type. The rotor shaft is geared to 
trie ?;heels at both endp . Great care is taken to have . 
absolute alignment of the pinion ad gear teeth, thus 
reducing the strains or the gear teeth to a minimum. 

OPERATION OF THE OE-l.- The maxinmm tractive 
effort developed by this locomotive is 4o,000 pounds at a 
speed of 14 miles per hour; giving an output of i,700 
horse power. At starting it will exert a tractive effort 
up to th- slipping point of the wheels. As all its 90 
tons weight is upon the driving wheels as is not the case 
with a steam locomotive it is capable of exerting a greater 
tractive effort without slipping than a steam locomotive 
of tne same weight, it is a good freight locomotive and 
at the same time is fast a^d well adopted for passenger 
service in the tunnels. By coupling two of these units 
together they car: ~»e operated by the engineer in the 
forward one thus doubling the power. 



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FOURTH PURCHASE OF LOCOMOTIVES.- A second 3 ir 
of loco'Otivee of she D stroit Tunnel byoe were provided 
for tne tunnel se -vice, in i3i2 so t n-" t this type »ay 
now be considered as standard for the present electrifi- 
cation . 

ALTERATIONS IN POWER SYSTEM.- in 1914 our chased 
power was used for all the light and cower re qui rem ante 
of electricity for the railroad at Baltimore. This exten- 
sion of electric service po inroroved the load factor that 
t'ie Mt . Rov;-:l batterv was rot "scepsarv and wa? cor-serment- 
dis-fantled. A 2,000 K.f. rotary converter was then 
installed in the substation p-ivl^a- it enough capacity to 
sipply power to two train? of a trailing weight of 2,340 
tons each. All the rotary converters rrentioned were 
secured from the General Electric Company and aire in use 
at present so that the equipment of the substation 
consists of 3-1000 K.F, and 1-2000 K.I. rotary converters, 
giving the plant an output capacity of 5000 K,W. 

OPERATION IN 1921,- The laximuaa traffic over the 
Belt Line in 1921 was about 2250 tons including the steam 
locomotives of about 230 tone. These trains can be hauled 
up the maximum grade fcv two OE-1 or OE-2 locomotives at 
at about 15 railee per hour. This a'^oufc twice the speed 
ofwhich the Mallet Ftea^ locomotive is cans^le under similar 
conditions . 

A BUSINESS ASSET.- The BtkQ lool^s upon this electri- 
fication as a business asset. Thev want the public to know 



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about it. They have gone so far a? to advertise this 
electrification on car cards showing one of their Detroit 
tunnel type locomotives in service at the tunnels. Their 
sts.tetr.ents concerning the electrification leave no douot 
in the readers mind that they are justly proud of this 
engineering feat.