|Railway Signaling (Chicago IL)
Signaling Change on Canadian Pacific
By Franklin George
Signal Wireman, Canadian Pacific, Toronto, Ont.
The Canadian Pacific has recently installed signals protecting train movements at West Toronto, Ont., which presented a signal problem with various complications to be taken into consideration, owing to the combination of through train moves and switching moves with various possible routes.
Passenger train routes were not affected in the change. Therefore, only freight and switching moves will be considered. An average of 15 freight trains daily enter the West Toronto yards from the east, while 12 trains leave the yards for the east. An average of 8 trains daily enter the yards coming from the north, while about 7 trains leave the yards bound for the north. These freights often consist of 90 to 110 cars, and most of the trains leaving the yard for both east and north are double headed. The helpers eventually return to the yards as light engines. A fair estimate of the number of times the local switching engines pass through the routes affected would be about 40 times daily.
Referring to the track diagram, it will be seen that all eastbound trains leave the yards and proceed east on the eastbound main track. All trains from the east enter the yards via the westbound main track. In order that trains from the north can be routed to the yard, they are routed over the track marked "L" extending from switch 28 on the north and south line to switch 20 on the westbound main line. Therefore, these trains from the north must move against the current of traffic on the westbound main track until east of signal 57 (8) and then back into the yards. Trains leaving the yards for the north back up easterly on either the eastbound or the westbound main track until east of either crossover 111-333 or signal 57 (8), and then pull out headed north. The use of the westbound track by freight trains from the north going to the yard or from the yard to the north, made necessary the additional signaling protec tion explained in this article. As a general rule, the westbound main is used for such a move.
The majority of the trains to or from the north are foul of the C. N. crossing east of Davenport interlocking, and often east of signal 1L or 53 (2L), by the time the other end is clear of the West Toronto plant and Oster Avenue. Many times an eastbound train will be moving east, while at the same time a train to or from the north will be occupying the westbound main track.
The new signals installed were 35, 2Ra and the automatic signal 43. Signal 39 replaced a dwarf and was put up on the new cantilever bridge, as were signals 38a and 38b, which were formerly on a ground mast. Signal 44 was formerly 42b, but being controlled by a new lever 44 its number was changed accordingly, and old 42c became 42b. Signal 2Rb replaces a dwarf and was placed on a new cantilever bridge with signals 2Ra, 1Ra and 1Rb, the latter two of which used to be on a ground mast.
Signals 8a, 8b, 8c, and 2La, 2Lb, and 1L remain as before. Signal 49 (4L), previously an approach signal for signal 2L, was made an absolute by the addition of a red marker light. Signal 43, mounted on a new cantilever bridge, was installed as an approach signal to 49. These signals are identified by number plates corresponding to mileage, but for circuit work are designated by the lever number and its position.
The interlocking machine at West Toronto is an English Saxby & Farmer, the plant being electro-mechanical. Circuit controllers are attached to the tail levers and the electric locks are the Saco latch-lever locks. The Davenport interlocking machine, located at Symington avenue, is a Union table interlocker Style "TC." Three levers were added in spare spaces at West Toronto; No. 34, 35, and 44. One lever was added to the Davenport machine; No. 4. The Davenport interlocker controls signals on both the C. P. and the C. N., protecting the crossing. The West Toronto plant controls signals on both the C. P. and the C. N.; also derails and switches.
The route from signals 60B and 02 to signal 49 on the westbound main track is traffic-locked by lever 34 in the West Toronto tower, where an operator is located. This operator is in full charge of the entire route, with the exception of the signals protecting the Davenport crossing, which is handled by a lever and gateman located as mentioned before at Symington avenue. This Davenport leverman has control of signal 49 (4L) only by authorization of the West Toronto operator, which he secures by means of a local yard telephone and, of course, by the position of lever 34, which controls the 34FR relay through which the controls of signals 4L, 2La, and 2Lb are broken. Lever 4 is interlocked with lever 2 so that if 4 is in L position, 2 cannot be moved to R position, or if 2 is in R position 4 cannot be put in L position.
Lever 34 at West Toronto is interlocked with the levers affecting the route from N or K to M, so it can only be reversed when such routes are set up. Signal levers 35 and 44 can only be reversed when 34 is reversed. Signal levers 39 and 42 are so interlocked with lever 34 that they can only be reversed when 34 is normal. Signal lever 8 may be reversed when 34 is either normal or reverse. Lever 34 is kept normal except when a train move, from N or K to M and the east, is to be made, for which signal 35 or 44 is to be used. Being normal, switching moves N or K to M may be made, for which signals 39 or 42b are used. The controls of signals 39 and 42b are not broken through the track relays. Therefore, they act as call-on signals. This latter move will not affect a train being brought in from the east via signals 4L and 2La or 2Lb except by ordinary blocking. Switching crews accepting signals 39 or 42b protect themselves against westbound moves as formerly by observation of standard rules, when east of signal 57.
Track and signal diagram of territory where signal and interlocking changes were made
Typical Home Call-on and Distant Siqnal Controls
As will be noted by the accompanying circuit diagram, the clearing of the eastbound signals on the westbound main track at West Toronto, or westbound signals on the same track at the Davenport end, or the occupancy by a train, or the opening of a switch affecting said track between signal 49 and 60B and 02, will de-energize the 34FR and 34LR relays. This holds lever 34 locked in its last position, and the neutral contacts of the 34FR will be open, but the polar contacts will retain their last assumed position. The control of 35-44HD relay is broken through the switch and track repeaters, and is poled reverse when signal 2Ra is displaying green, thus allowing a green to be displayed by signals 35 or 44. This type of a track and switch repeater circuit was used rather than switch circuit controllers to shunt a-c. track circuits and also to eliminate the necessity of carrying numerous circuits through the switch circuit controllers. The 53AR circuit, which provides annunciation for the operator at West Toronto, was extended east to signal 49 (4L), broken through 4L and 2L red repeater relays and the track and switch repeaters. Thus, when the 53A light on the track diagram at West Toronto is lighted, the operator is aware that the track east of his plant is either occupied, a switch is open, or a westbound signal is cleared, and he will not expect to find lever 34 unlocked or to be able to clear signal 35 or 44. His procedure under such circumstances would be to telephone Symington avenue tower for information. The EAR relay, which provides annunciaation for the man at Symington avenue, is de-energized (annunciating position) only after lever 34 has been reversed and signal 35 or 44 cleared, or the track occupied while 34 is reversed. The signal control circuits should be self-explanatory.
All of the signal levers are equipped with electric locks, which, in the event of a signal being cleared and then not accepted by a train, or a signal not assuming the stop position, will prevent the lever from being restored to its full normal position. In the former case, a time release provides the necessary time element release.
Indicators were placed at the end of crossovers between the eastbound and westbound main tracks, so that train crews will not bring their train from the eastbound over on to the westbound when a train is approaching on that track.
The circuits were designed in the signal engineer's office at Montréal, and the installation was made by the Ontario District construction force under the supervision of the signal supervisor.
Traffic lock and associated circuits
Railways: C.N.Rys., C.P.Ry.