secure before proceeding. With only one train permitted in any one
block at a time, it would not be in danger of backing into another
train moving up behind it. The positive block method would generally
be used in radioactive areas. Train operation in such areas is
discussed in paragraph 2.17.
2.3. TRAIN ORDER OPERATION
adequate number of passing tracks and facilities are operational,
is possible that all train movements in a theater will be made by
train order. This method is flexible and efficient; however, in a
singletrack operation, passing tracks or sidings must be available.
Paragraphs 2.42.8 discuss the train order in terms of who originates
it, how and to whom it is issued, and what it contains; train order
rules and forms; clearance form "A"; and the dispatchers' record of
all trains moving on the division.
2.4. TRAIN ORDER
A train order is the authority for trains not provided for in
timetables to move from one point to another on a railway division.
It is written on DA Form 55203, shown in figure 1.2 in paragraph 1.
6 and again in figure 2.1. The order is issued by a train dispatcher
by the authority and over the signature of the chief dispatcher,
orally, by radio, or by telephone, through a station agent who writes
it as received and repeats it back to the sender for a check of
accuracy. The written order is handed to passing train crews. Train
orders are numbered consecutively each day beginning at 0001 hours;
they are in effect until fulfilled, superseded, or annulled. Figure
2.1 shows one issued by a train dispatcher to run an extra train from
station Alfa to station Delta on the rail line shown in figure 2.2.
With the train order in figure 2.1 and a Clearance Form "A,"
explained in paragraph 2.7, Engine 411 is authorized to run as Extra
411 East from Alfa to Delta. It must clear all opposing regular
trains and all regular trains moving in the same direction but it may
pass second, third, and any other inferiorclass trains.
Additional orders must be issued if it is to meet another extra
train. Remember that a train order is in effect until it has been
fulfilled, superseded, or annulled. It is always addressed to those
who are to execute it: conductors, enginemen, station agents, or
anyone who is acting as a pilot; its body must be in the same words