July, 1943 RAILWAY SIGNALING 355 Left-Control machine. Be­ low-signals 36-38 and crossover 37 location, look­ ing north toward the tower

New installation increases the · flexibility of operations, mini­ mizes train delays, improves utilization of tracks, provides for either-direction train operation, and promotes efficient coordi­ nation of many train movements

Canadian National Installs aLarge All-Relay Electric Interlocking

AT ST. LAMBERT, Que., the Canadian at these various locations. The sig­ terlocked crossover, 37, was added National has installed a new all­ naling was arranged primarily for at the south end of the wye, and the relay electric interlocking which not right-hand running on the double east leg of the wye was changed only replaces a Model-2 electric in­ track. The operation of trains on from double track to single track. terlocking installed in 1913, but also the double track over the Victoria At Southwark West, three new in­ includes a more extensive track lay­ Bridge between St. Lambert and terlocked crossovers, 45, 47 and 49 out, and provides for either-direction Montreal was right-hand running were added as a means for facili­ train operation on each main track. with automatic signal protection. tating train movement into and out The previous Model-2 interlocking Because of the greatly increased of the yard, as well as to assist machine, with conventional mechani­ number of train movements, and as in making run around train move­ cal locking between levers, and with a part of a terminal improvement ments. This arrangement of cross­ . electric lever locks, had 41 working program being carried out in this overs and switch 43, together with levers. This plant included Model-2 area, various changes and additions the signals, form the Southwark electric switch machines, Model-2A were required in the interlocking at West portion of the new plant. semaphore high signals and solenoid St. Lambert. Crossover 1 was added At Southwark Centre, crossover type dwarfs. The track layout in­ to the interlocking in order to facili­ 61 had previously been operated by cluded an eastbound-to-westbound tate either-direction train operations hand-throw stands. As a part of the crossover at the St. Lambert station, on the two main tracks. Switch 9 improvement program, crossover two switches on the Sorel branch, with derail on the line to Sorel, 69 was added and it and 61, both be­ · one on the west end of the south which was formerly operated by tween the two main tracks, were siding, and the switches at the three hand-throw stand, was equipped equipped with switch machines. ends of the wye, as ·well as signals with a switch machine. A new in- Electric locks were installed at the 356 RAILWAY SIGNALING July, 1943 west end of 59, at the east end of in contacting the engine or train of the tracks and just east of the St. 63 and the west end of 67. This lay­ crews. The power-operated main Lambert station. The upper floor of out, including the signals, forms the line crossovers for trains moving to the tower, including the control ma­ Southwark Centre portion of the or from the Southwark yard facili­ chine, is the operating room. The new interlocking. tate movements, especially for ton­ ground floor is divided into two At Southwark East, a few changes nage trains. . rooms, one for housing the relays were made in the track layout and New 110-volt d-e. switch machines and the 110-volt switch battery, and the crossovers as shown, which had were installed throughout the plant. the other for maintainer's headquar­ formerly been on hand-throw, were The 19 switch machines located in ters. equipped with electric switch ma­ the general vicinity of the tower and The new .interlocking machine is a chines and interlocking signals were at Southwark West are the Model floor model with a vertical .. .uperating installed, this layout forming the 5C, and the 12 remaining switch ma­ panel surmounting a desk:)helf and Southwark East portion of the new chines at Southwark Centre and at a height convenient tq; operate interlocking. About 0.6 mile east of Southwark East are the Model 5D either from a standing po~ition or Southwark East, a crossover from with dual control. The four electric sitting on a stool. The desk shelf in-

...... Wes+ -To Monfrea/

05

45 B Bungalow A

when the corresponding switch is When a signal has been cleared by and when traffic direction has been locked, because of track occupancy, rotating its knob, the knob must be established, the face of the knob is the clearing of a signal, or when restored to its normal position after illuminated as a blue background time locking is in effect. In other the train has accepted and passed the around a white arrow. Only one words, when the red lamp is lighted, signal, because the call-on aspects lamp is used in each of these traffic nothing would be accomplished by are not controlled by track oc­ direction knobs. throwing the lever. A small indica­ cupancy. Knobs controlling dwarf The crossing of the M. & S. C. R. tion lamp is located in tlre face of signals are arranged to rotate only R. with the Canadian National at the panel below each switch lever. and the manipulation for clearing Ranelagh, south of St. Lambert, is This lamp is lighted white whenever the position of the lever does not correspond with the position of its switch or crossover. The lamp is extinguished as soon as the switch or crossover has operated to and been locked in the position called for by the position of the lever. Each high signal is controlled by a combination knob and button Type SA dwarf which is located on the diagram on signals bridge­ the "track" and at the place corre­ mounted on sponding with the location of the Victoria Bridge signal controlled. The knob as a whole can be pushed or pulled to effect certain controls, or the outer rim can be rotated to effect other controls as will be explained later. The inside barrel of the knob does not rotate. The lens of the face of this barrel has a dark colored arrow which points in the direction which the signal controls. Behind the bar­ rel are two independently controlled lamps, which are normally ex­ tinguished. such signals, or for restoring them to protected by an interlocking which Having previously positioned the stop, is the same as described for is controlled automatically, except switches for a given track line up, call-on signals~ that, by means of a knob on the the top or middle arm of a high As previously mentioned, there is panel, the operator at St. Lambert signal can be cleared by pushing the a dark colored normally non-illumi­ can hold the. northward signal knob corresponding to the signal to nated arrow on the face of the center (R-71), at Ranelagh at the Stop as­ be controlled. When a train accepts of each signal control knob. When pect. This feature was provided so and passes the signal, it is controlled a knob is manipulated with the in­ that inbound freight trains can be to the Stop aspect, with stick control, tent of clearing a signal for a route held at Ranelagh where they are and no further action is required on having all switches properly posi- clear of other trains as well as street July, 1943 358 RAILWAY SIGNALING crossings, and also at that location wye crosses the normally eastbound four little switches each of which the trains are on a slight down grade main track. A trap circuit provides controls a maintainer's call lamp where they can be started easily. protection for this dead section.. If, and horn at four corresponding loca­ Two rotary type levers are located on account of some unusual opera­ tions on the plant area. Normally in the upper left corner of the panel. tion, the trap circuit is locked out, these switches stand in the center One of these is used to vary the the plant would be tied up. In such position. When a switch is pushed

The Model 2 interlocker which has been removed from service

brilliancy of the indication lamps on an instance, the operator can look to the down position and held, then the control panel, being set for out the window and make sure that at the corresponding field location "Bright" during sunlight hours, or the dead section is not occupied. a horn is sounded. When placed in on "Dim" during darkness or dull Then, after breaking a seal, he can the up position, where it may be left days, thus obviating eye strain for operate a special pushbutton on the until the maintainer answers the call, the operator. The other lever con- panel that will cause the trap circuit an amber colored light will be dis­ played at the corresponding field location. The maintainer carries a portable telephone, which he can plug in at any field location to talk with the operator, a special circuit being provided for this purpose.

Power Off Indications and Controls

The track circuits throughout the interlocking are of the alternating current type, which means that, if the a-c. power fails then no switch can be operated, and no signal in­ dication can be given, on account of a-c. lighting. Above the track dia­ gram on the panel there are four buttons marked "POWER," each being located in a position corre­ sponding to (1) the tower, (2) Southwark West, (3) Southwark Centre, and ( 4) Southwark East. A lamp is provided behind each button. Normally these lamps are extin­ Model SD switch machines, equipped with outboard brakes guished, but if the a-c. power fails at any of these locations, the lamp in trois the brilliancy of the signal to be restored to normal. the corresponding button is lighted lamps, "Bright" for daytime, and On account of the extended area red. At the same time all track lights "Dim" for hours of darkness: of the plant, a means for calling the and lock lights for the area affected There is a dead section of track maintainer was desirable. Across will be lighted and no switches can through the diamond crossing where the control panel and immediately be moved. the east track of the west leg of the below the track diagram there are When the a-c. source again be- July, 1943 RAILWAY SIGNALING 359 comes energized, the track circuits permitting the possible throwing of the relays is used in the tower and will automatically become energized a switch in front of a train without in the outlying sheet-metal houses as will signal and switch repeater the necessary time delay being intro­ as well as in the separate cases. Each circuits and . any call-on or dwarf duced the same as required in con­ rack in bungalows and cases is signals previously cleared will again ventional approach locking. mounted on springs to absorb vibra­ clear. In the case of high signals, By placing the restoration of nor­ tion which may be caused by passing it would be necessary to repeat the mal operation under the control of trains. The racks were assembled manipulation of the knob to again the operator, he is kept alert and in­ and wired in the factory, so that in­ clear them. However, as a safety formed of any abnormal conditions sofar as these racks are concerned feature, a contact in a power-off arising in the field. the only wiring required in the field relay is incorporated in the source of was to run the incoming cables and energy for the local switch locking Quick-Detachable Pluq-In Relays attach the wires to terminals or ar­ circuits which will prevent the lock restors mounted on terminal racks relays from picking up until such In the tower, one room on the separate from the relay racks. time as the operator pushes the ground floor is assigned for housing "POWER" button on the control the relays, battery, rectifiers, etc. Features of the Route-Selection panel and then awaits a predeter- At each of the field location areas, Network Circuits Southwark West, Southwark Centre, and Southwark East, there is an 8-ft. The circuits at this St. Lambert by 10-ft. welded sheet metal house. interlocking are conventional except Welded sheet metal cases are located that the route selection networks in­ at various signals and other points clude several novel and interesting on the plant area. features. By properly arranging the The track relays are the double­ networks, and taking advantage of element vane type, and the remainder the large number of contacts avail­ of the relays are the d-e. 10-volt type. able in the Type-B plug-in relays, All of the relays are the quick­ it was practicable to locate all of the detachable plug-in type. Plugs, pro­ networks entirely within the tower. truding from the molded bakelite An advantage is to minimize the plugboards fit into receptacle con­ number of control and indication tacts on the rear of the relays. Each wires between the tower and the re­ of the racks supporting the plug- mote points, and also the localizing

Relays-Name, and Use GZ =Signal Control Relay Controls operation of signal CGZ = Call-on Signal Control Relay Controls operation of call-on signal RR = Route Relay Prevents setting up opposing routes NWC = Normal Switch Correspondence Checks switch control relay and switch Relay repeater in normal position RWC = Reserve Switch Correspondence Checks switch control relay and switch Relay repeater in reverse position TP = Track Relay-Repeater Repeats position of T relay RP =Red Signal Repeater Repeats red position of signal LR =Lock Relay Electrically locks operation of switch machine TES = Time Element Stick Relay Provides time or approach locking CTES = Call-on Time Element Stick Provides time or approach locking with Relay call-on signals ES = East Route Stick Relay Provides release route locking for east­ bound moves WS = West Route Stick Relay Provides release route locking for west­ bound moves Y G P =Yellow-Green Signal Repeater Repeats yellow and green position of signal . M · = Home & Distant Signal Repeater Repeats home signal at red and distant at red and yellow RK = Red Signal Indication Relay Repeats red position of opposing signals at remote locations WP = Switch Repeater Repeats position of switch machine WCP = Switch Correspondence Repeater Repeats position of NWC and RWC relays WZZ = Switch Control Relay Controls operation of switch machine LP = Lock Relay Repeater Repeats position of lock relay Key to symbols used on page 361

of such selections in the tower fa­ Relay housing with spring-mounted boards is 24 in. wide, thus affording B relay rack space in a horizontal row for four cilitates inspections and mainten~nce. relays of the B-2 type or eight relays Typical route-relay and stgnal · o~ the B-1 type. Eight such hori­ control circuits are shown in the mined 'time interval, introduced by a zontal panel rows, and two groups accompanying diagrams Fig. 1 and thermal time element relay in the of terminal boards, one at the top Fig. 2. A special operating feature field. This prevents the possibility and the other at the bottom are is that all the switches in a proposed of a momentary power outage oc­ bolted to channel iron uprights, the track line-up must be over and locked curring at the time of a train ap­ whole of which constitutes a rack, in position for the route desired, as proaching a signal from releasing which is about 8 ft. high. This same indicated by the movable-point in­ the route locking and subsequently type of construction for mounting dicators and correspondence _lamps July, 19-13 360 RAI LWAY SIGNALING below the levers, befo1·e the oper­ moves his finger from the knob and knob 90. As a result relay 90GZp ation of a signal knob will be effec­ it springs back to its normal posi­ is energized with its polar contacts tive. The method of attaining this tion. Then circuits are closed to to the right which completes the objective will be evident from the energize relay 90RR in series with circuit to energize the operating coil following discussion. 84RR. Battery BL now feeds of searchlight unit signal 90C. through front 3 of 90RR, front 4 The feature of ··this arrangement Network for Remote Locations of 90GZ to energize 90GZP with the is that, with the selections of the polar contacts to the left. In the high or diverging route signals made The circuits shown in Fig. 1 apply meantime lock relays 89LR, 87LR by local circuits at the remote loca­ with reference to a signal knob as·­ and 85LR have been released, thus tion, it is possible to control the two sociated with a signal which is completing the circuit to energize top "arms" as well as the call-on remote from the tower; for example, the operating coil of searchlight sig­ "arm" of a signal by one GZP relay, signal 90 at Southwark East is the nal unit signal 90A, which causes a which is located in the relay house at most easterly interlocking home Proceed aspect to be displayed. the remote location ; in this instance signal, and signal 84 is the opposing If the track line up had included at Southwark East. One advantage signal. Push operation of signal crossover 85 reversed, then relay is to minimize the number of wires knob 90 closes a contact which com­ 8SWCP would be reversed and the between the tower and Southwark pletes a circuit starting with battery GZ-RR network would have been East. NL, through the push contact, completetl through 82RR, the op­ through a front of 85TPP, the coils posing signal route relay with cross­ A Different Arrangement for of 90GZ, back 1 of 90RR, front 1 over 85 reversed. 85NWC would Near Locations of 84-90RK, normal polar and front have been down and 8SRWC up with neutral of 89WCP, front neutral and the result that the operating coil of An arrangement different .. from normal polar of 87WCP, front neu­ searchlight signal unit signal 90B that discussed above was used in the tral and normal polar of 85WCP, the would be energized to display a Pro- . area in the general vicinity of the

84 84 RK(red} 84·90RK 84Gl 11~_.....--MIO ~n) 846Z 84RR

viCJ xover 85 reverse·

Bunq>Jiow C~ I

Jig.

M N84C6 Sig. via xover viet xover via xover 84G L 84CG 85 reverse 87 reverse 89 reverse "-=--+-.::....:.C'-"'----,

Fig. 1-Typical route, GZ and GZP relay circuits, remote location coils of 84RR, back 3 of 84GZ, back ceed aspect on the middle "arm." tower. Referring to Fig. 2, when 1 of 59RR and/ or neutral front and If a call-on aspect is to be dis­ signal knob 16 is pushed, a contact normal polar of 61WCP, back 1 of played on signal 90, the knob is is made which completes a circuit 72RR, through the closed N contact rotated which closes the R contact from battery NL through the knob of 84 knob and to battery BL. This and opens the N contacts, and a push contact, through the upper coil energizes relays 90GZ and 84RR in circuit is completed to energize re­ of relay 16GZ, front contact of series. Relay 90GZ sticks up through lays 90GZ and 84RR in series. but 1STP, back of 16RR, back of its own front contacts so that it is 90RR is not energized because its lSRWC, front of lSNWC, back of not released when the operator re- circuit is open at the N contacts in llRWC, front of llNWC, back of July, 1943 RAILWAY SIGNALING 361 17RWC, front of 17NWC, back of circuit for the operating coil of completing the circuit to energize ?.4GZ, back of 24CGZ, coils of 24RR, searchlight signal 16A so that th~ relays 16CGZ and route relay 24RR back of 46RR, closed contact N in signal then clears. Then relay 16RP in series. Contact 2 of 16CGZ oper­ knob 24 to battery BL. Thus th.e is released and contact 1 of this relay ates the indication lamps in the face push of knob 16 causes its corre- extinguishes the red lamp and lights of knob 16 as previously explained.

17TP 24GZ

for rou+e vi

I 1 Typicl!tl roufe (!!'>c/ GZ relay circuif I ) ::r---BL RP /r.Gz near locer+ion (16 & Z4) /6RK (red 16 • NXI~~BXIO ~~~z I 8 YGP A/6TP /6TES /6GTE5 z /6RR N/0 JRWG 810

Signer/ Sequence (read down} ievers Gonfacf made when knob pushed r Signer/ knob operated {pushed) ~Con-lac+ m6de wifh knob normal Y ·. r;~nd maintained when pushed. opens when knob pulled or fumed -

--@---Confacf made wifh knob. rofafed 90' right

-@-- ContCicf made with knob normal, opened when knob pushed, pulled or rotateol. Track light Two·coiltype B relays . illuminated Two·cod may be series. mult•rJie,or =8= {independently connected. Gl relay drops Signer/ qoes io sfop Ligh+ in signal RP .rel"y picks up ,------NL knob goes out -""---+--c.----"' N/0 Tf5 rel"y picks up --.1....:~- ~t65 j~t6Sjt-~t 1 l,t55I1--BIO Tmin accepts and passes nexf siqnal -+-1i_ra_ck relery picks up -,--:1-:-T_P..,.re.,...lay picks up Track liqhfqoeso Roufe sfick and lock rel

sponding GZ relay, 16GZ, and the the green Iainp in face of knob 16. Contacts 3 and 4 of 16CGZ and con­ RR, route relay 24RR, at the exit If the second "arm," 16B, is to be tact 3 of 24RR complete the circuit end of the track line up, to be ener­ cleared, .. the operation would be for the operating coil of the bottom gized in series. similar to that discussed above, ex­ "arm" 16C. . With 16GZ energized, front con­ cept that in this instance switch 15 In the circuits shown in Fig. 2 ' tact 1 completes the circuit to feed would be reversed and dwarf signal and discussed just above, it will be the lower coil of 16GZ. Front con­ 18 would be the opposing signal. As noted that' two· relays, GZ and CGZ, tact 2 of 16GZ completes the circuit a result, relay 15NWC would be are used in connection with the push, to light the red lamp in the face of down and lSRWC up, which would pull or turn of a signal knob. The the 16 knob. Front contacts 3 and select the circuit to the operating coil positioning of these relays is de­ 4 of 16GZ close in the circuit to the of signal 16B instead of 16A. pendent on whether the knob is operating coil of searchlight signal If the call-on "arm" 16C is to be pushed or rotated, and this deter­ 16A. Also with relay 24RR ener­ cleared, the 16 knob is rotated 90 mines whether a high or a call-on gized, front contact 2 completes the deg. which closes the L contact thus signal is cleared; therefore the op- 362 RA I LWA Y S I GN ALING July, 1943 eration of the RR relay at the en­ switches have not completed opera­ relays as shown in Fig. 1, the re­ trance end of the route network is tions when the signal knob is oper­ quired indications, RK and GK, for not required. ated, the GZ relay cannot pick up all units of two opposing signals. immediately and the RP relay will Since route networks are broken How Preconditioning of Signal drop. The dropping of the RP relay through switch correspondence re­ Control is Prevented will prevent subsequent picking up lays or repeaters thereof, depending of the GZ relay, and it then becomes on whether a near or remote location, The signal control circuits are so necessary to return the signal knob and thus make it impossible for a arranged that they, in addition to to normal in order to pick up the GZ relay to pick up and subsequently the route selection network (GZ and RP relay before again attempting to put route locking into effect before

16Y6P /6Y6P N/0

NIO IIORP

~Bun

1-Bunq(:f /o~ G I I 89 89LP 89WZi

89WGP

BIO 89 WE(correspondence)

89/l ·BWR "'-'--~-' - -- -} To switch w__,_ _ _,1!'!§}_11: machine Fig. 4-Typical switqh or crossover control BWR 89!1 & B and indication circuit-remote location I Bunqalow C --1 the signal knob in multiple with but it is not considered essential circuits used for the control and front contacts of the associated GZ in these. cases as it would be neces­ indications of a switch located in relays (see Fig. 3), and a front sary for the operator to deliberately the general vicinity of the tower. contact of the RP is incorporated in hold the signal knob pushed in the pickup circuit of the respective longer than usual to cause a GZ relay Pre-condition Control of Switches GZ relays that are energized by ro­ to subsequently pick up. Prevented tating the signal kriob. If the route Note that typical remote location is properly set up, the GZ relay will signal indication circuit, 84-90RK, As previously met:;~tioned, nothing pick up immediately upon operation shown in Fig. 3, provides, through would be accomplished by throwing of the .signal knob. If, however, the the selection made through the GZ a switch lever when the red lock July, 1943 RAILWAY SIGNALING 3b3 light is lighted. Likewise, the fact transformers the primaries of which split battery, of 54-a.h. capacity that the lock rel~y was down at the are supplied 80 or 110 volts, depend:. charged from 2 Type BT232 recti~ time the lever was thrown would ing on the position of the "DIM" fiers is used for remote control and prevent any subsequent movement relay for the par_ticular location. indication circuits to the three of the switch after the locking does All the "DIM" relays are controlled bungalows. release. by the one lever previously men­ Each of the three bungalows con­ This is accomplished by breaking tioned as being on the control panel. tains two sets of storage batteries the initial pickup circuit of the WZZ ' through the lock relay and in turn controlling the pickup circuit of the Jock relay (for near locations), or the lock relay repeater (for remote locations), through NC and RC con­ 17WR tacts on the lever in conjunction -----} To switch with polar contacts of the switch L-~--~I--'N-'-'I"-7.:.:..:W~---- mc;rchine 17 repeater or switch correspondence 17 WP repeater relay, depending on wheth­ -- ---} from switch er a near or remote location. '-+------;'!-'N'-"1'-'-7-'-'W-'-P__ _ _ mc;rch ine Jl Referring to Fig. 4, it will be noted that a movement of the lever N/0 to_ the reverse position, with lock relay 89LR picked up, will permit : 17 RWC NL to flow through the RC ~ever 810 :'~N/0 conta,ct, the top coil of 89LP; the I front stick contact of 89LP (89LP I is made slow release to bridge lever I movement and WCP pole-changing BL To II &- 1-'-5"-L R-'---, time), the -normal polar contact of NL -89WCP, the front of 89LR and the two coils of 89WZZ to CL, picking 89LP and 89WZZ up in series, pole­ changing 89WZZ to reverse. Switch movement to reverse will now be effected. If, however, 89LR had been down at the time the lever was moved reverse, the 89:UP-89WZZ series circuit would have been open at the-front of 89LR and the 89LP would be down. With the front stick ·Movable-po int contact of 89LP open, a completion indicator of the 89LP-89WZZ series circuit in event the 89LR eventually pjcked up would be impossible. Under such Sequence {read down} conditions, it would . become neces­ - - sary to restore the lever to normal Switch lever opera ted reverse long enough to re-establish the 89LP-89WZZ circuit and permit the Correspondenc er . WZZ relay ptcks up reverse 89LP to close its front stick contact. light lighted NWC relay drops wRand C2 relays i!J swiTch A circuit arrangement basically mcrchine operate the same, is shown in Fig. 5 for near locations. In this case, the pick­ WP relay drops 5witch mrxchine opercrting up circuit of the LR relay is con­ -~ to r:everse trolled through the WP and the lever, and the WZZ circuit is an in­ WP relay picks C2 relay drops fo sfop mo+or dependent circuit broken through up reverse contacts on the lever and the LR. Gorresponden eel 1, Movable point RWC relay picks up lighf goes ov+ indicator reverses Power Supply (Followed by opercrtion of st~nc;r/ knob, if required} Fig. 5-Control and indication circuit for switches near the tower Alternating current power at 2200 volts single phase is distributed over the plant area with 2200/110- The tower relay room contains all of 54-a.h. lead type. Fifty-five volt transformers at the tower and three sets of storage batteries. Fifty­ cells charged from a BP248 rectifier at the sheet metal houses at the more five cells of 120-a.h.lead type battery are used for switch machine oper­ remote locations. The track circuits charged from a Type BP248 rectifier ation, and 5 cells charged from a are fed from low-voltage transform­ are used for operation of switch ma­ BT132 rectifier for local circuits and ers, using reactance feeds for the chines in the vicinity of the tower. control circuits originating in the long circuits and resistor feeds for Five cells of 120-a.h. battery charged bungalow. Energy for remote con­ the shorter circuits. Ten-volt signal from a Type BP248 rectifier are used trol and indication circuits is sup­ lamps are used throughout the en­ for local circuits in the tower and plied directly from 2 Type BK116 tire interlocking home signal limits control circuits originating at that rectifiers feeding 12 volts d-e. direct- and are fed direct from 115/10-volt point. In addition, a 6 plus 6 cell -(Continued on page 372) RAILWAY : SIGNALING July, 1943 372 are carried in aerial cable·. on pole No. 14 cable extends to each switch Interlocking on C.N. lines. machine, and a 7-conductor to each (Continued from page 363) Throughout the interlocking un­ dwarf signal. A pedestal mounted ly to the busses. Where energy is derground cable is used for cross­ junction box is provided near each required in outside relay housings runs to switches and signals as well switch machine and dwarf, the cable to feed switch and signal indication as for track connections. The track wires being terminated in these circuits, track repeater circuits, etc., connection cables are No. 9 single­ boxes, with 19 strand No. 14 with this too is supplied directly from a conductor extending to individual 5/64-in. insulation extending to the rectifier of suitable capacity. cast-iron bootleg pedestals where the machine or signal. The relatively small capacity of conductor is soldered to a double At the ground mast high signals the storage batteries will be noted. strand of No. 6 Copperweld which a separate cable, either 5 or 7 con­ Since a-c. track circuits are used, is pinned into the rail. A 9-conductor ductor extends to each searchlight signal unit, thus eliminating jumpers between signal units. At each signal bridge there is an instrument and terminal case near the bridge leg. Nineteen strand No. 14 single-con­ ductor wires with 3/64-in. insulation are made up in cable from the case to the bridge structure, and extend up and across the bridge into the masts in conduit to protect against locomotive smoke fumes. The installation of this new inter­ locking was made by the General Railway Signal Company; of Canada, Limited, under the general super­ vision of R. G. Gage, Chief Electrical Engineer, and J. J. Ginty, Signal Superintendent of the Canadian Na­ tional Railways. The signal equip­ ment was furnished by the General Railway Signal Company; the switch fittings, bootleg castings, and outside wire as well as aerial and underground cable being purchased in Canada. ''

Above-Type B relays, power rack, etc. in tower. Right­ Eastbound signals 46 and 48 at Southwark West. the entire plant will be tied up by an a-c. failure. The storage batteries are thus provided primarily to serve as a "flywheel" to smooth out varia­ tions in load and maintain a more uniform voltage than would be ob­ tained if direct feed from rectifiers had been used. The circuits west from the tower to signal bridge 6-8, east of the tower to Southwark West, and south on the wye to signal 38 are in underground cable. East of Southwark West and westerly from signal bridge 6-8 over Victoria Bridge, and south from signal 38 to approach signal R-65, the circuits