August, 1943 RAILWAY SIGNA LING 409

Right-The panel of the new interlocking machine. Below-Island Junction showing home signal 12R

Switches, signals and derails scattered over a square mile, are controlled by one machine Pacific Electric Installs a Large All-Relay Interlocking

·A LARGE all-relay, electric interlock­ Long Beach. A new double-track scattered over an area about a mile ing has been installed by the Pacific connection was built between a point square. In reality, the one new ma­ Electric Railway at Terminal Island now known as Watson Junction and chine controls five layouts, each of Junction, which is located in the south a point now known as F lint Junction, which would be a separate interlock­ part of Los Angeles, Cal. T his new thus connecting the east-and-west line ing if local controls, such as mechani­ interlocking is a part of a project in­ with the north-and-south main line cal interlockings, had been used. cluding track changes and extensions between Los Angeles and San Pedro. The first layout, at Flint Junction, to provide rapid transit passenger At a point now known as Island Junc­ includes, one power switch, No. 25; service between Los Angeles and the tion, two south legs were built to form one spring switch, No. 27; and three ship building yards on Terminal a double-track wye, and a new double­ home interlocking signals, No. 26R, Island, as well as between Long track line was built from Island J unc­ No. 28LA and No. 28LB. The top Beach, Cal., and Terminal Island. tion 2.5 miles to a station on Termi­ "arm" of signal 26R governs on the The accompanying plan shows, in nal Island. straight track to San Pedro and the solid lines, the tracks formerly in lower "arm" governs via the connec­ service, and, in dash lines, the tracks Five Interlockings in One tion to Watson Junction, with power which were added to provide the new switch No. 25 normal. · passenger service. Second main track The various track layouts con­ Spring switch No. . 27, at Flint was added on the east-and-west line trolled from the new Terminal Island Junction, is set normally so that the between Wilmington Junction and Junction interlocking machine are points are not moved when a trailing 410 RAILWAY SIGNALING August, 1943 move is made by a train from Watson sociated with spring switch No. 23, unlocked when the derails are re­ Junction through Flint Junction. Sig­ determines the selection between sig­ versed on the Southern Pacific and nal lever 28, when thrown to the left, nals 24LA and 24 LB in a manner home signals on both the Southern clears either signal 28LA on the con­ previously explained. Pacific and the Pacific Electric are in nection from Watson Junction, or sig­ the "stop" position. A trainman can­ nal No. 28LB on the old main line Protection at Crossing of the Pacific not unlock the electric locks, without from Wilmington Junction to Flint Electric and the Southern Pacific first having the towerman reverse the Junction. In order to establish a se­ derails. lection between the controls for sig­ A single-track line of the Southern nals No. 28LA and No. 28LB, a Pacific crosses the double track of Terminal Island Junction Layout switch lever No. 27 is associated with the Pacific Electric at a point just The Terminal Island Junction lay­ out ip,dudes three power switches : No. 9, No. 11 and No. 13 ; three spring switches marked "SS" but with no numbers, and three two­ "arm" home signals. Train move-

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spring switch No. 27. This lever con­ ' I trols a polar switch control relay at ~ -~L ,," / Flint Junction just the same as if a L1: ______,. ______.,., ,' ,... ~' power switch were involved. Neutral ,,' , ... ------·------·- d-e. relays, one for normal and one ,' ,' ·--f\': I I for reverse, are controlled through I i the polar contacts of the polar relay, .I ' T' and the selections for the controls of I Fig. 1-Track and signal I signals 28LA or 28LB are through plan of the interlocking front contacts of the respective neu­ which is controlled from tral relay. the one panel type machine

Watson Junction Layout

The layout at Watson Junction in­ cludes power switch No. 21, spring switch No. 23, signals No. 22R, 24LA

west of Alemeda Street, which is ments are single-direction right-hand about 900 ft. east of Watson Junc­ running, and no provision is made tion. Previously no protection was in for signaling to direct "back-up" service at this crossing, all trains on moves. The position of power switch both roads being required to stop and No. 13 determines the selection be­ whistle before using the crossing. tween the top and the bottom "arm" Protection at this crossing is included of signal 14L, likewise the position in the new interlocking. Signals 18R of power switch No. 11, selections for and 20L direct trains over the cross­ signal 12R, and power switch No. 9 ing on the. Pacific Electric tracks. No selects for signal lOR. The opera­ "back-up" signals are provided for tions do not require selection levers reverse train movements. On the associated with any of the three Southern Pacific, there are two pow­ spring switches, because the selections er-operated derails, both being con­ in each route are already determined trolled by lever No. 15. The two by the power switch in the track line home signals 16R and 16L are con­ up before encountering the spring Signal 28LB at Flint Jet. trolled by lever 16. Two spur tracks switch for a trailing move. enter the main line of the Southern and 24LB. The position of power Pacific at hand-throw switches with­ Layout on Ford Avenue switch No. 21 determines the selection in interlocking home signal limits. An between the top and bottom "arms" electric lock was installed on each of The new double-track Pacific Elec­ of signal 22R. Switch lever 23, as- these switches. These locks may be tric line south from Island Junction August, 1943 RAILWAY SIGNALING 41 1 crosses a single-track line of the At­ lighted red when the electric locking sound is picked up by a microphone chison, Topeka & Santa Fe, and two is in effect to prevent operation of mounted on a post beside the track, ingle-track lines of the Union Pa­ the switch even if the !everman oper­ and the sound is reproduced in a loud ~ific. The three crossings are so close ated the lever ; in other words, this speaker in the tower at Terminal together, on the Pacific Electric, that one northward home signal, No. 6R, and one southward home signal, No. 8L serve on the Pacific Electric. The ho~e signals on the A. T. & S. F. are :Nos. 4L and 4R. The second Union Pacific track was added after ·the interlocking was planned, and, therefore, switch No. 1 is now operated by a hand-throw stand. As soon as materials can be secured, a switch machine will be in- · stalled at switch No. 1 and a second arm will be provided on signal 2L. Signals 2LA and 2LB, as well as sig­ nals 2RA and 2RB, will be selected through the position of the switch. Dual-control electric switch machine

Panel Type Control Machine is a "hands-off" lamp. Island Junction. This sound, in con­ There are 14 signal levers in the junction with an indication by the Considered as a whole, the new in­ bottom row. These signal levers nor­ track-occupancy lamp for this ap­ terlocking, controlled from the one mally stand in the vertical position, proach track section, informs the !e­ machine at Island Junction, includes on center. Three levers, No. 2, No. verman that he should line up for

Insulated gage plates and adjustable rail braces

5 power switches, 2 power-operated 4, and No. 16, operate either to the main-line derails, 2 electric locks on left or to the right position to clear hand-throw switches, and 20 home correspondingly numbered L or R interlocking signals, of which 14 have signals. The remaining eleven signal one operative unit and 6 have two op­ levers operate either to the R or the erative units. L position to clear the corresponding­ The control machine for the new ly numbered signal. The indication interlocking is of the panel type with lamps above the signal levers repeat an illuminated track diagram and two the normal Stop aspect of the signals, rows of miniature-type levers. No or the Proceed aspect of the signal controlled by either the R or the L mechanical locking between levers or Signal 26R at Flint Junction electric lever locks are included in position of the corresponding lever. this machine. Five levers each control The lamps in the illuminated track a single power switch,. one lever con­ diagram are lighted when the cor­ a route via Flint Junction through trols two power-operated derails, and responding sections of· track are oc­ Watson Junction and Terminal Island two levers each are used to establish cupied. Junction. selections for signal controls over spring switch No. 23 at Watson Junc­ Microphone Annunciators Signals and Switch Machines tion and switch No. 27 at Flint J unc­ tion. When trains approaching on a cer­ The signals in this interlocking are Three indication lamps are mount­ tain track may take either one of two . the searchlight type and are operated ed above each switch lever. The lamp routes, the !everman must be in­ by 250-ohm direct current coils. The at the left is lighted green when the formed accordingly. For example, lamps in the signals are the double­ switch is in the normal position, and when a southbound train en route for filament type rated at 10 volt 13 + 3.5 the lamp at the right is lighted amber Terminal Island approaches Flint watts. when the switch is in the reverse po­ Junction, the motorman sounds a long The switch machines are the Model sition. The lamp in the center is and a short blast of the whistle. This M22A, with dual-control, and equipped 412 RAILWAY SIGNALING August, 1943 for operation on 110-volts a-c. At nue. At each of these five layouts, tacts of a lock relay in the local sheet, each switch, l-in. by 9-in. insulated there is a 5-ft. by 7-ft. welded sheet metal house, and then one wire goes gage plates are used on three ties, and metal instrument house which in- to the center tap between the twG adjustable rail braces are provided on eludes the local track and control re- rectifiers in series, and the other wire these plates. Two of the plates extend lays, as well as local interconnections goes to the tower and is connected to 9 9 13 II N lo-...... ---{ R N r---vvvvv---, Fig. 2-Typical switch control circuit ®

cc-----;

CN and are attached to the switch ma­ of circuits. The control circuits from the hinge of the polar contact of the chine, thus preventing lost motion. the interlocking machine to each of polar switch repeater relay. The ties are clapped 4.5 in., so that these five instrument houses, as well As shown in the diagram Fig. 3 the base of the machine is 4 in. below as the circuits for the return of indi­ power switch No. 9 is controlled by the level of the base of the rail. cations to the tower, are all direct­ polar relay 9WR. In the control cir­ wire circuits. cuit for 9WR lever repeater relay Track Circuits and Power Supply The position of each interlocked 9WLPR is normally energized. When switch is repeated by two neutral lever No. 9 is thrown to the reverse On account of the fact that direct relays, one for normal and one for position, a circuit is closed from bat­ current propulsion is used on the Pa­ reverse, these relays being in the local tery CN, through a reverse lever con­ cific Electric, the track circuits are sheet-metal house. Each of these tact 9R, the coil of 9WLPR, another the alternating-current type, using neutral relays has a repeater in the reverse lever contact 9R, the front Model 15 two-element vane relays or tower, such as relays 9NWKR and contact of 9WLPR, the left polar Style SLV13 single-element vane re­ 9RWKR in Fig. 2. When switch No. contact of 9WKR, a front contact of lays. 9 is in the normal position, 9NWKR lock relay 9LR, the coil of switch All control circuits are d-e. and are is energized, which closes the circuit control relay 9WR, another contact fed from constant potential rectifiers which are fed from a-c. power. The direct-wire remote control circuits are fed from rectifiers in series, arranged CN to provide the equivalent of a split battery connection. The overall volt­ age of this d-e. is 35 volts, and the maximum rated output of the recti­ fiers is 1.9 amp. The signal lamps are fed from low­ voltage transformers, approach light­ cc ing control being provided. By means of a switch on the panel of the inter­ locking machine, relays at the various cc layouts can be controlled and C'Jn­ tacts of these relays control circuits through the primaries of the lighting cc transformers to dim the lights during ~------a,N~rKR~~--~M CN hours of darkness. The 110-volt a-c. switch machines are fed from trans­ formers. Thus directly or indirectly the switches, signals, control circuits, track circuits, etc., are all fed from Fig. 3-T:ypical signal agreement circuit the alternating-current supply, with no battery standby. This practice is to energize polar switch-repeater of 9LR and to center feed connection satisfactory in this instance because 9WKR with the polar contacts to the of battery CC. Thus the polar switch the Pacific Electric cannot operate left. Relays such as 9NWKR and control relay is reversed, and the trains if the electric propulsion sup­ 9WKR are the L-type relays, and switch is operated to the reverse posi­ ply fails. are housed in the case of the inter­ tion, after which switch position relay locking machine. 9WKR is reversed. Control Circuit Arrangements The operation of each switch ma­ The purpose of lever repeater re­ chine is controlled through the lay 9WLPR is to prevent pre-condi­ From the standpoint of circuits, neutral and polar contacts of a DP- tion or switch storage control of a there are five separate and independ­ 25, d-e. 280-ohm polar relay, which switch control relay. ent propositions : ( 1) Flint Junction, is located in a case near the corre­ For example, if a train occupies (2) Watson Junction, (3) Southern sponding switch machine. Such a a track section that locks switch No. Pacific Crossing, ( 4) Terminal Island switch control relay is controlled by 9, then relay 9LR would be released Junction and (5) the U. P. and the a two wire circuit; both wires of and, as a result, relay 9WLPR is A. T. & S. F. crossings on Ford Ave- which each extend through front con- released. As long as the front con- August, 1943 RAILWAY SIGN ALI N G 413

tact of 9WLPR is open, operation of Appro01ch Locking Relay Circuits lever No. 9 will be ineffective in House I operating relay 9WR. Therefore, be­ IORRGPR IORAR I POSR fore switch No. 9 can be reversed, IORASJ IORAS2 IORASI IORAS IN the !everman must wait until after the train clears the track section to 18 IO RASR permit lock relay 9LR to be ener­ o·ized and then the lever must be "laced ' normal to pick up relay ~WLPR, after which the switch can be reversed by placing lever 9 in the reverse position. The indication circuits from the instrument houses back to the control /2RRGPR 12RAR IPOSR 111achine are fed from indication 12RAS3 f2RAS2 12 RASI 12RAS IN transformers with 17.0-volt second­ aries. Selection thro.ugh rectifiers is 18 12RASR provided to carry two indications over one wire, with either one or both operating at any one time. 12RTE IN Signal Control Interconnections ,Mt2RTER '------~- The interconnection of signal agree­ ment circuits through the L-type re­ 14LR6PR 14LAR IPOSR lays in the interlocking machine, are /4LASJ 14 LA 52 14 LAS/ 14 LAS shown in Fig. 4.. For example, if IN switch No. 9 is normal, and lever No. 14LASR 10 is thrown to the right, then battery feeds from CC through front con­ tact of switch repeater 13NWKR. through 9N lever contact, through ~ front contact of 9NWKR, back con­ :ciJ. I4LTER tact of 9RWKR, through the l OR lever contact and the coil of relay lORHSR to battery CN. After relay Power Off Relay lORHSR is thus energized, it stays House I picked up by a circuit through its own IORASPR 12RASR 14 LASR front contact to battery CC. As long IPOS /POS/ IPOS2 18-BX/10 as lORHSR is thus stuck up, circuits t=a,._,sR~--~""'18"'--_,.Bc:...:.X.:..:.If.::..O __'-*_ ___.l to energize control relays for conflict­ ing signals cannot be complete, be- Fig. 4-Approach locking circuit

effected by DT-10 time element re­ lays. The DT-10 time element relays are adjustable from 0.5 to 6.0 min­ utes. If the a-c. power should fail, the approach locking relays and the power-off relay will drop. The ap­ proach locking relays will not pick up until after the power is on and the time element relay has operated. After all the approach locking relays are energized, the power-off relay is picked up to restore the a-c. feed to the plant. The circuit for accomplish­ ing these results automatically · are shown in Fig. 4.

Automatic Block Signaling

On the 2.5 miles of the new double Home signal lOR at Island J unction track line between Terminal Island Junction and the station on Terminal cause back contacts of lORHSR are with 9WR switch control relay, Island, new automatic block signaling open. Also inadvertently moving checks the switch locking circuit was installed as a part of the im­ switch lever 9 or any other switch or through front contacts of the 9LR re­ provement project. These signals are signal control levers on the control lay and lights the hands-off light over of the searchlight type and are panel will not drop relay lORH SR the switch lever when the relay is mounted as dwarfs. The signaling is and kick-off signal lOR in the face down. for single-direction train operation, of an approaching train. · Approach locking protection is pro­ right-hand running, the blocks being . The 9WLPR relay, being in series vided with automatic time release approximately 1,200 ft. long, to space August, 1943 414 RAILWAY SIGNALING trains on approximately two-minute headway. These signals are controlled by neutral a-c. track circuits, in com­ bination with polar a-c. line circuits. The signal lamps are controlled by ap­ proach lighting circuits. Right- Interior of Bridge Over Cerritos Channel instrument case at Terminal Island Jet. The new section of railroad crosses the Cerritos Channel, between the main land and Terminal Island, on a double lift bascule bridge. On each side of the bridge, double track con­ verges to single track which extends over the bridge. The ends of double

volts direct current which is fed from rectifiers. The interlocking equip­ ment at this drawbridge location was furnished by the General Railway Signal Company. The major items of equipment for the Terminal Island Junction inter­ locking and the new automatic block signaling were furnished by the Union Left- Micro­ Switch & Signal Company. phone at home These new interlockings and sig· sign a 1 No. naling were installed under the di­ 26R at Flint rection of A. Orin Smith, signal en­ Junction gineer of the Pacific. Electric. L. H. Cash is assistant signal engineer in charge of plans and engineering, and W. E. Stratman is foreman of the field forces. track switches are operated by Petti­ bone Mulliken oil buffer spring switch mechanisms. On each of these switches there is a General Railwav Signal Company Type-A automatic mechanical facing-point lock. The single track over the draw bridge is protected by a derail and a Right-A north­ home signal on each side, Model SB bound car pass­ switch machines and Type SA search­ ing signal 28LB light signals being used. These inter­ at Flint Junction locking derails and signals are con­ trolled by levers which were added to an existing Model-2 unit lever in­ terlocking machine which was pre­ viously in service to control inter­ locking protection for a Union Pacific single track over this same bridge. The switch machines are rated at 110-