Train dispatching in a theater of operations necessarily differs from
that on commercial railroads.
In a theater where civilians operate the
trains and the military control them, dispatching may remain unchanged if
passenger-train service is continued.
However, troop, ambulance, and
ammunition trains may be assigned even higher priority than passenger
As armies advance, however, and the railroad is operated by the
transportation railway service exclusively for military purposes, the method
of dispatching trains may undergo radical changes dictated by the particular
combat or logistical conditions.
Retreating enemy forces may destroy
line. When service is resumed, what was formerly a double-track, high-speed
road with automatic block signals may be a single track with restricted
speed and an improvised signal system.
difficult and complex.
Single-track operation will prevail; light trains
carrying less tonnage at lower speeds will be the rule; and circumstances
will determine movement priority.
In single-track operation, dispatching is carried out by written train
orders. These are the dispatcher's instructions received over telephone or
telegraph wires by operators along the line who copy them in longhand and
deliver copies to the train and engine crews to whom addressed. As chapter
5 explains, many types are used to cover every conceivable situation, and
they may be either helpful or restrictive. They tell a crew what to do--
never what not to do, and they frequently carry qualifications.
Basically, a first-class train depends upon the timetable schedule for
its authorization. On leaving the starting terminal, the crew is authorized
to travel along the route according to the published time figures in the
schedule columns of the timetable.
On a single-track line, the timetable
specifies the superior direction, for example, eastward.
first-class train traveling east (Maxey to Conroy, figure 1.1) would be
superior to all other trains on the line. The crew would expect all trains
in each direction to clear and not delay their train. A crew with a first-
class train traveling west--Conroy to Maxey--would expect all trains except
first-class eastbound trains to clear them. "To clear" means to get a train
completely off the main track by going into a siding or yard, and to line
the switch for the main track.