Following are the topics/questions discussed in this section of the OpSig Primer. You can click on a question to jump directly to that topic. You are invited to address further questions or comments (please refer to question number) to firstname.lastname@example.org.
With these procedures in place, what is left for the Dispatcher to do?
Answer 1: The dispatcher is the 'traffic cop' of the mainline between large yards. He authorizes trains to start out from their origin station and directs how they move along the mainlines, which ones have priority, and (if on single track) where they will meet and pass each other. If trains are scheduled on a timetable (much more common before about 1980) they can run along and meet each other according to the schedule, but if someone gets delayed or if an unscheduled ('extra') train is needed, the dispatcher steps in and issues the necessary instructions ('trainorders').
On busy lines the dispatcher may be able to control signals from a central control panel ('centralized traffic control') and trains just follow the signals. On lines where CTC is not in effect, the dispatcher issues orders. Originally they were transmitted by telegraph, then telephone, and delivered to train crews in written form by operators at towers or stations along the line. When train radio became common the dispatcher could give instructions directly to the crews. There are specific rules and procedures to avoid misunderstanding and conflicting track occupancy. These have changed over time; up to about 1980 the method was referred to as 'timetable and trainorder' (TT&TO). Currently methods called Track Warrant Control are used.
On a model railroad people can look ahead to see if anyone else is using the line they want, or just yell, 'Here I come.' But to operate in a realistic manner someone should act as dispatcher and instruct the crews. Various methods are used which more or less accurately reflect the real world. You can get the flavor of some of these by participating in operating sessions in your area.
A2: A running order is always used for extras, but also for regular trains starting from other than their initial stations on a subdivision (or district), and to authorize all sections (outside 251 and 261 territories). The timetable schedule gives running rights (and relative superiority) to scheduled trains, but they must be given a 'clearance' form to start out on their schedule. Other orders can go to any type of train (meets, rights over, waits, sections, etc). Each train affected has to be given a copy. So if you write a meet order ( No 1 meet Extra 1234 West at Dora.) you have to give a copy to train No 1 and to Extra 1234 W.
A3: It is the address, 'to Conductor and Engineer' Engine 1234, No 1, Extra 1234 West, etc.
Q4: Are train orders generally reused between sessions like the waybills, or used just once per order? Could you squirrel away the used trainorders and other paperwork after an op session, first, to save investment and second, to draw from like a deck of cards (never know what you might get)?
A4: TOs are throwaway items because they are issued to modify a schedule to meet some unanticipated event. Thus the odds of needing the same TO a second time are quite remote. Plus TOs are numbered, and the numbering restarts every day. Thus you would need to reuse the TOs in the same order each time. Not gonna happen!
These are not operating instructions which tell you what duties the train is to perform, rather it changes where the train is to meet another (for example). Usually TO forms are cheap pads of paper which are thrown away after use. -- Bob Gerald