The New York Subway

Engine Shaft

anding the marked progress recently made in its development, it can scarcely yet be considered to have reached a stage that would warrant any modifications in the plans adopted, even were such modifications easily possible at the present time. The comparatively limited headroom available in the subway prohibited the use of a

ELEVATIONS

ION OF ALTERNATOR WITH PART C

ear or two of the beginning of operation of the system, while the plans permit convenient and symmetrical increase to meet the requirements of additional demand which may develop. Each express train will comprise five mot

es per hour, while the control system and motor units have been so chosen that higher speeds up to a limit of about thirty miles per hour can be a

ur, while north of 96th Street on both the West side and East side branches their speed will

f three-phase alternating current at 11,000 volts, this current to be generated at a frequency of 25 cycles per second, and to be delivered through three-conductor cables to transformers and converters i

GALLERY IN

1,000 VOLT CIRCUITS

proximately 50,000 kilowatts, and having in view the possibility of future extensions of the system it was decided to design and construct the power house building for the ultimate reception of eleven 5,000-kilowatt units for traction current in addition to the lighting sets. Each 5,000-kilowatt unit

er

ppropriate to refer briefly in this place to certain considerations governing the s

ES-MAIN PO

-an alternative deemed inadvisable by the engineers of the company. The adoption of a smaller unit would be less economical of floor space and would tend to produce extreme complication in so large a

ss output than this, the alternators must be put in service at intervals of twenty minutes to

ngineers decided in favor of reciprocating engines. This decision was made three years ago and, while the steam turbine sin

COMPARTMENTS-M

ern

y are three-phase machines, delivering twenty-five cycle alternating currents at an effective potential of 11,000 volts. They are 42 feet in height, the diameter of the revolving part is 32 feet, its weight, 332,000 pounds, and the aggregate weight of the machine, 889,000 pounds. The design of the engine dynamo unit eliminates the auxiliary fly wheel generally used in the c

BAR COMPARTMENTS-

ROSS 58TH ST

steel, and the rim is carried not by the usual spokes but by two wedges of rolled steel. The construction of the revolving field is illustrated on pages 91 and 92. The angular velocity of the revolving field is remarkably uniform. This result is due primarily to the fact

ING BOARD IN

TRUMENT BOARD-M

heavy steel end plates are bolted together, the laminations breaking joints in the middle of the pole. The field coils are secured by copper wedges, which are subjected to shearing strains only. In the body of the poles, at intervals of approximately three inches, vent

SENGER STATION

being in the form of a small keystone. This may be removed readily, affording access to any field coil, which in this way may be easily removed and replaced. The armature winding consists of U-shaped copper bars in partially closed slots. There are

n-inductive load, the alternators will have an efficiency of not less than 90.5 per cent. at one-quarter load; 94.75 per cent. at one-half load; 96.25 per cent. at three-quarters load; 97 per cent. at full load, and 97.25 per cent. at one and one-quarter

000 CABLE FOR 11,0

ci

he marine type, to which they are direct-connected, while the remaining three units are direct-connected to 365 horse-power tri-phase induction motors operating at 400 volts. A storage battery capable of furnishing 3,000 amperes for one hour is used in co-operation with the dyn

ing dynamos just coming into service with those already in operation the allowable difference in phase relation at the instant the circuit is completed is, of course, but a fraction of the fiftieth of a second. Where the power to be con

ing Ap

bars are used, and the connections are such that each alternator and each feeder may be connected to either of these sets of bus bars at the will of the operator. From alternators to bus bars t

OF TUNNEL SH

nt of the company's business should require that number. But eight sub-stations are required at present, and to some of these not more than

d in groups, each group being supplied from a set of auxiliary bus bars, which in turn receives its supply from one or the other of the two sets of main bus bars; means for selection being provided as in the case of the alterna

N SIDE WAL

ith automatic overload and reversed current relays, and the feeder switches, as above mentioned, are provided with automatic overload relays. These overl

OR PLAN SUB-S

his switch when opened introduces in each of the three sides of the circuit two breaks which are in series with each other. Each side of the circuit is separated from the oth

ION SUB-ST

F SUB-STAT

SECTION SUB-S

cted of brick, small doors for inspection and maintenance being provided opposite all points where the bus bars are su

PS OF TR

ged vertically and are placed directly beneath the rows of oil switches located upon the main floor of the power house. Above these rows of oil switches and the group bus bars, galleries are constructed which extend the entire length of the power house, and upon the first of these galleries

ATTERY BOARD FOR CONTR

W. ROTARY

ontro

s make or break the relatively feeble control currents, which, in turn, close or open the switches in the main power circuits. The control switches are systematically assembled upon the control bench board in conjunction with dummy bus bars and other apparent (but not real) metallic connections, the whole constituting at all times a correct diagram of the existing connections of the main power circuits. Every time the operator changes a connection by opening or closing one of the main switches, he necessarily changes his diagram

ERNATING CURRENT FOR BLOCK SIGNAL

tors to the bus bars and the other for the connection of feeders to bus bars. The

strume

left and the feeder panels at the right. For the alternator panels, instruments of the vertical edgewise type are used. Each vertical row comprises the measuring instruments for an alternator. Beginning at the top and enumerating them in order thes

alternator and feeder instruments. Provision is made on the back of the board for convenient connection of the standard instruments in series with the instru

the ammeters belonging to the feeders which supply a given sub-station, and from left to right these are in order sub-stations Nos. 11, 12, 13, 14, 15, 16, 17, and 18;

opping to reach the scales of the instruments will tell him whether the feeders are dividing with approximate equality the load to a given sub-station. Feeders to different sub-stations usually carry different loads and, generally speaking, a glance

ING CURRENT BLOCK SIGNAL

F SUB-STAT

ibution to Sub-Stations P

eing 12/32 of an inch. These conductors are installed in vitrified clay ducts. From dynamo switches to bus bars and from bus bars to group and feeder switches, vulcanized rubbe

stem for D

comprising thirty-two ducts, have been constructed. These conduits are located on opposite

F SUB-STAT

Hall to 96th Street (except through the Park Avenue Tunnel) sixty-four ducts are provided on each side of the subway. North of 96th Street sixty-four ducts are provided for the West-side lines and an equal number for the East-side lines. Between passenger stations these ducts help to form the side walls of the subway,

of cables in one of these manholes, resulting from short circuit in a single cable, all cables except at the joints are covered with two layers of asbestos aggregating a full 1/4-inch in thickness. This asbestos is specially prepared and is applied by wrapping the cable with two strips each 3 inches in width, the outer strip covering the line of junction between adjacent spirals of the inner strip, the wh

OARD-SUB-ST

alternating current from the power house through cables carried on opposite sides of the subway. To protect the lead sheaths of the cables against dam

ergy from Power Ho

ted from its neighbors and from the lead sheath by insulation of treated paper 7/16 of an inch in thickness. The outside diameter of the cables is 2-5/8 inches, and the weight 8-1/2 pounds per lineal foot. In the factories the cable as manufactured was cut into lengths corresponding to the distance between manholes, and each length subjected to severe tests including application to the insulation of an alternating current potential of 30,000

-St

e high potential cable system to eight sub-stations containing the necessary transfor

T CURRENT FEEDER

o. 11-29-33 C

. 12-108-110 E

. 13-225-227 W

. 14-264-266 W

. 15-606-608 W

. 16-73-77 Wes

side Avenue, 301 feet W

Fox Street (Simpson Street), 60

TING FEEDER T

L JOINT WIT

converters with necessary transformers, switchboard and other auxiliary apparatus. In designing the sub-stations, a type of building with a central air-well was selected. The typical organization of apparatus is illustrated in the ground plan and vertical section on pages 101, 102 and 103 and provides, as shown, for two lines of converters, the three transformers which supply each convert

T RAIL

100 feet in length, but the lots acquired in these instances being of unusual width, these sub-stations are approximately 60 feet wide. Sub-station No. 12, on account of limited ground space, is but 48 f

EDERS FROM MANHOL

transformers, which are arranged in groups of three, receive the tri-phase alternating current at a potential approximating 10,500 volts, and deliver equivalent energy (less the loss of about 2 per cent. in the transformation) to the converters at a potential of about 390 volts. The converters receiving this energy from their respective groups of transformers in turn deliver it (l

LS, SHOWING

rnating current circuits are opened and closed by oil switches, which are electrically operated by motors, these in turn being controlled by 110 volt direct cur

tor, while facing the bench board and the instruments, to look out over the floor of the sub-station without turning his head. Th

tograph on page 93, and are in a line facing the boards which carry the direct feeder switches, each circuit breaker being located in a compartment directly opposite the panel which carries the switch belonging to the corresponding circuit. This plan will effectually prevent

ONTACT RAIL A

onductors, now well separated, extend vertically to the fixed terminals of the switch. In each sub-station but one set of high-potential alternating current bus bars is installed and between each incoming cable and these bus bars is connected an oil switch. In like manner, between each converter uni

ersed current relay, which, in the case of a short-circuit in its alternating current feeder cable opens the switch and so dis

RAIL I

Distribution fr

feet, and north of 96th Street the average distance is about 15,000 feet. Each track, of course, is provided with a contact rail. There are four tracks and consequently four contact rails from City Hall to 96th Street, three from 96th Street to 145th Street on the West Side, two from 145th St

SHOE A

rom sub-stations Nos. 13 and 14; from 96th Street to 143d Street, on the West Side, they are supplied from sub-stations Nos. 14 and 15; from 143d Street to Dyckman Street they are supplied from sub-stations Nos. 15 and 17; and from that point to the terminal they are supplied from sub-st

clear, we may consider that section of the subway which lies between Reade Street and 19th Street. This section is equipped with four tracks, and the contact rail for each track, together with the direct current feeders which supply it from sub-stations Nos. 11 and 12, are electrically insulated from all other circuits. Of each pa

herefore, interchangeable. The connections are such as to minimize "track drop," as will be evident upon examination of the diagram. The electrical separation of the several contact rails and the positive feeders connected thereto secures a further important advantage in permitting the use at sub-stations of direct-current circuit-bre

is 60 feet, but in some cases 40 feet lengths are substituted. The contact rails are bounded by four bonds, aggregating 1,200,000 c. m. section. The bonds are of flexible copper and their terminals are riveted to the steel by hydraulic presses, producing a pressure of 35 tons. The bonds when in use are covered by special malleable iron fish-plates which insure alignment of rail. Each leng

gs. Castings of the same material are used to secure the contact rail in position upon

k Bo

and the other is utilized as a part of the negative return of the power system. Adjacent rails to be used for the latter purpose are bonded with two copper bonds having an aggregate sect

frequent intervals for the purpose of

Guard and C

e 113. This guard is carried by the contact rail to which it is secured by supports, the construction of which is sufficiently shown in the illustration. This type of guard has been in successful use upon the Wilkes

hird rail system in Chicago, Boston, Brooklyn, and elsewhere. The shoe is shown in the photograph on page 114. The shoe is held in contact with the third rail by gr