Train Control, Signaling, and Switch Heaters
War and its associated transportation demands were punishing the
Western Pacific. Along with every other employee, the burden of war
traffic had tremendously increased the problem of the Chief
Dispatcher, whose duty it was to distribute the engines and crews to
the points where they were needed, in order to protect the business.
This additional workload had been brought about by a 104% increase
in freight traffic and a 610% increase in passenger traffic in the
period 1938-1942, inclusive, with an increase in motive power of
only seven steam and three diesel electric road locomotives for both
the Eastern and Western Divisions.
Where formerly there had been very few helper or double-header trains eastbound in the Feather River Canyon, now the eastbound Exposition Flyer was double-headed almost daily, except when over sixteen cars, when a 251 class mallet had to be used. Cars were being loaded so heavily that many trains with mallet and diesel electric road engines had to be helped to Keddie or Portola. Eastbound drags of empties were being handled in 74-car lots with two consolidation engines double-headed. The increased use of helpers eastbound was found to be working to the railroads advantage in handling the greater preponderance of westbound tonnage from Portola because it required only one engine to handle a “Fast Freight” train westbound from Portola regardless of its tonnage. WP was taking advantage of this fact by handling westbound trains with the small engines wherever possible. This, in turn, permitted many large mallets to run light from Portola to Oroville immediately upon their arrival at Portola, and made them available at Oroville that much sooner. About one-half of the big mallets in service had to make the round trip between Oroville and Portola within a day's time, in order to keep traffic moving.
Heavier trains on the Exposition Flyer in both directions now required helpers to Altamont almost daily. There was so much war traffic going to the bay area, helpers from Stockton to Altamont were required on practically all westbound “Fast Freight” trains, and there were many more of them than formerly.
Troop movements in both directions offered their own individual problems because of their varying length and weight. Many of them had to be helped to Altamont in either direction and often required the use of a 251 class mallet east of Oroville.
Traffic on the Bieber line also increased at the same rate as the main line. Heavier loaded cars required more helpers than formerly and it now took four engines on southbound trains from Bieber that three used to handle. This often necessitated using a diesel electric to "pinch-hit" on the line when traffic got beyond the capacity of the small mallets assigned to that subdivision.
With the exception of the Humboldt Valley, the eastern division was practically all desert, crossing the south end of Great Salt Lake marshes, Wendover salt beds, Jungo hardpan flats and the Black Rock desert.
Helper districts were: Westbound, Delle to Low, Wendover to Hogan,
Jungo to Antelope and Gerlach to Portola, Eastbound: Sulphur to
Antelope, Sonar to Silver Zone and Clive to Low, helper engines and
crews being stationed at Delle, Wendover, Jungo and Portola.
The 178 miles of track between Weso and Alazon was operated under paired track agreement with the Southern Pacific Company; WP handling all eastward trains and SP all westward trains of both companies between these stations. Traffic was exceedingly heavy in this territory and parking out and spacing freight trains to avoid serious bunching of them ahead of several passenger trains required a diligent watch at all times. The two-position Style “B” semaphore signals installed on this paired track was the only continuous signal protection in service on the Western Pacific.
Because of the extraordinary volume of wartime freight and passenger traffic moving to and from California over the WP, a very large part of which must pass through the 118 mile Feather River Canyon in the Sierra Nevada between Oroville and Portola, California, the War Production Board granted WP the necessary authority to proceed with installation of a complete Centralized Traffic Control (CTC) signal system through the canyon in 1943. CTC is operated by means of wayside three position light signals and coded track circuits. Power for operation of switches was furnished by storage batteries, trickle charged from a power supply so operations could be effected even when the power line supply was temporarily interrupted.
The War Production Board also released the necessary materials to enable the railroad to make an immediate start on the new construction and carry it to completion. Construction headquarters were established at Keddie and work gangs proceeded both ways from the control center. Materials required include 480 tons of iron and steel, 80 tons of copper and copper alloys, and a ton of nickel. Various sections were completed and placed in operation in the fall of 1943.
All signal equipment was furnished by the Union Switch and Signal Company of Swissvale, Pennsylvania. The project came under the general direction of Thomas L. Phillips, Western Pacific Chief Engineer in San Francisco with E. P. Peterson, Assistant Engineer, in active charge of the project. J. L. Coles, Signal Engineer, was in charge of plans and field installations. All line wire and pole line work was under the direction of J. P. Quigley, Superintendent of Transportation and Telegraph at San Francisco.
The work was expedited so that the new system could be placed in operation at the earliest date practicable. The Keddie to Portola unit was completed and placed in operation around the end of 1943 and the Keddie to Oroville unit was completed early in June 1944, at which time the entire Feather River Canyon was under CTC operation.
|Trains passing through Keddie under CTC control. Mileposts|
This included 26 sidings all of which were equipped with power
switches. Coded track circuits of reversible type were used for the
field control of trackside signals exclusively on this installation.
Normally, the track circuits were fed from steady energy and all
signals would display their most restrictive aspect. When the proper
controls were sent to the field control stations, located at the
power switch installations, the steady energy was changed to coded
energy and fed from the exit end towards the entrance end of the
block involved at speeds of 75-120-180 pulses per minute, depending
upon conditions in the area ahead. Coded track energy was received
and decoded permitting signals to display yellow, flashing-yellow or
green, depending on the code speed received.
In the station to station blocks the steady energy could feed in either direction depending upon the last signal line-up used. Within siding areas coded track circuit control with reversible code was used to provide signal protection on both the main track and siding without the use of additional CTC stations. In those areas normal steady track energy was feed westward on the main track and eastward on the siding. Continuous track indication for all main track and sidings was displayed on the CTC machine with this arrangement.
The control machine for this installation was located at Keddie and the line control consisted of two direct-current line circuits with one carrier circuit. The carrier circuit extending from Keddie to Cresta (37 miles) in turn controlled the direct-current line from Cresta to Oroville (79 miles).
The use of such a signal system permitted the movements of all trains on the district to be directed by the dispatcher at Keddie, 96 miles east of Oroville. Trains were now directed only by signal indication without use of written train orders and all passing track switches on the entire district now electrically opened and closed by remote control from the control board at Keddie.
|Keddie CTC Panel.|
Through the medium of a moving train position graphic chart and
train indication lights on the track diagram before him, the
dispatcher had at all times a complete picture of the location of
all trains on the entire district. With this knowledge, the
dispatcher planned train meets or passings, set the signals at
outlying points to carry out his plans and also operated the
switches by remote electrical control to save the stops and starts
and loss of time which would be required if the train crew had to
operate the switches by hand.
The use of the new signal and train movement controls greatly shortened the time required for trains to pass over this mountainous district by eliminating time lost due to imperfect meets, transmitting and receiving written train orders and hand operation of switches when entering and leaving side tracks. In addition, complete automatic signals also provided additional safety of operation.