In the mid to late 1970’s the train order system was abolished in favor of Centralized Traffic Control, which divided the railroad into a series of blocks. Trains or track crews would be given authority to occupy specific blocks, depending on where it needed to go. For example, a train operating from McCloud to the Sierra Pacific Industries sawmill in Burney and return would have to get clearance to occupy the Bartle, Obie,
Cayton
,
Berry
, and Sierra blocks to make the movement. If there are no other trains or track crews working on the line the train crew would be given sole occupancy of all blocks for a certain amount of time. If, however, a maintenance of way crew is working in the Cayton block, then the train crew will be given sole authority to occupy all blocks except for the Cayton block, and the train crew and the maintenance crew will each be given joint work and time in that block with each other. Whenever joint work and time is granted, Rule 486 in the timetable is invoked:
“When joint work and time is authorized, movement can be made at authorized track speed only when there is an understanding between all those holding joint work and time of their specific location and the distance between them is no less than two miles.”
Other stipulations in the rule book spell out maximum allowable speeds within the DTC block that is held by two or more parties where no understanding between the parties is possible or can be reached. Blocks are released by those who have authority to hold them either by radio or by submission of a completed DTC block form to the dispatcher at the end of the tour of duty. In the scenario described above, if the maintenance of way crew finishes their work in the Cayton block and releases it back to the dispatcher before the train returns to McCloud, then the dispatcher will cancel the train crew’s previous joint work and time authority to be in the Cayton block, replacing it with an authority to occupy the block “all alone”.
Finally, here are a couple of other forms relating to train movements. The first is a switch list, which spells out what cars are to be handled in that trip. The second is a Track Conditions worksheet, with is issued to all train and track crews on a daily basis to inform them of any slow orders, malfunctioning crossing gates, out of service switches, or any other conditions that crews should be aware of.
