Train scheduling

I just read the book, “Water For Elephants” The story has trains pulling out of sidings as soon as they were loaded. Presumably onto main lines. If this is true, how did the schedulers and switchers learn about these ‘rogue’ trains and work them into the system? Thanks, Gerry in Canada

You’ve asked a question that has generated thick textbooks about the practice, and thick rulebooks to implement.

Assuming you are not on a line with Centralized Traffic Control, North American practice up to the early 1970s was operation by train orders and time table. To grossly oversimplify things, the timetable defines where the named trains (passenger and high priority freight) are to be at any time, and when they have authority to move to the next station or siding.

A junk freight would not be in the timetable, but would have an order from the dispatcher to proceed to a station, yard, or siding. They have direction to take the siding at some place and time to wait for traffic to clear.

In the 1970s, this scheme was replaced by the track warrant, which is similar to the previous train order, but is simpler to use, and eliminates the time table. Most lines that handle named trains are now on CTC anyway.

Thanks. So, the circus train sitting on its siding would be near a town with a station and would get clearance from that station to go to the next jurisdiction. Like air traffic control. Makes sense.

As Vunderbob noted, railroad dispatching is a wonderfully complex and exacting business. To clarify just a bit further; timetable operations governed nearly all train movements for much of the 19th century and at least the first half of the 20th. The timetable was a document that detailed all regularly-scheduled train movements within a given division of the railroad. Most trains operated on the same set schedule day after day. The railroad kept “operators” at station points along the route - generally every 5-10 miles. Each of these operators had contact with the dispatcher’s office via telegraph (later telephone). Each operator would notify the dispatcher each time a train passed his station. Further, each operator had under his control a trackside signal with which he could communicate limited messages to passing trains such as “stop here and wait for further orders”, “pass through without stopping” or “pick up additional orders on the move”. Train orders governed any deviation from the set timetable such as delays, sudden changes to schedules, etc.

Taking orders while underway was an interesting business; this was accomplished by clipping a tightly-rolled copy of an order to a hoop attached to a long staff. The operator would stand near the track holding the hoop at arm’s length, a crewman on the moving train would reach out and snag the hoop, unclip the order, then discard the hoop. Local youths were often paid a bit to scour the trackside and retrieve the used hoops for the operator. Usually, orders were passed to both the engine crew and the rear-end men in the caboose. Illistration here

Track warrant control came into use in the latter half of the 20th century, generally with the use of 2-way radio communications by which train crews could give progress reports and receive orders directly from the dispatcher without the need for operators along the line. Under track warrant control, scheduled trains and timetable operations are hardly ever used. Each train is a special movement or “extra” subject to the direct control of the dispatcher. Even today, track warrant control is used on many secondary and branch lines. Heavily-used mainlines are mostly under centralized traffic control (CTC) wherin all train movements are controlled from a central office.

In the matter of “junk trains” that you mentioned, these were special trains ordered out in addition to the regularly-scheduled “timetable” trains. On most railroads they were known as “extras” and had to be fit in between the movements of regular trains. Not only did they have to recieve updated orders as they moved up the line, but all other trains’ orders had to notify the crews of the non-typical movement operating in their territory. Usually extras were “inferior” to regularly-scheduled trains, meaning they were more likely to be required to wait on a siding for the “superior” train to pass. This was not always the case; some extras carried high-priority freight or passengers and were given rights over the timetable trains.

This is only a gloss treatment of a very complicated operation. For further information, Wikipedia has a fairly comprehensive article on the subject
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