Of course sometimes the train is too long and to pass another train they have to do a saw by.
How long ar train sidings.
By that time most class i railroads ran trains of 1 2 to 1 mile in length so a mile would be typical for passing sidings.
Sidings often have lighter rails meant for lower speed or less heavy traffic and few if any signals.
But that assumes the rest of the layout is large enough to support 30 car trains.
To implement longer trains railroad operators may run long trains in a single direction or fleet trains or extend sidings enough to facilitate bidirectional operation of long trains.
Railroads if at all possible tried to make passing sidings longer than the longest train to run on the line so normally a train wouldn t have to be squeezed into just fitting into a siding.
Generally the designation siding or main track is a matter of function.
A siding in rail terminology is a low speed track section distinct from a running line or through route such as a main line or branch line or spur it may connect to through track or to other sidings at either end.