Some railroads, including military railroads, do not use the 19 and 31
orders. The single green form shown in figure 5.1 is used instead. It is
known simply as a train order. Using it eliminates stopping a train for the
crew's signatures when the train is going to be restricted at a point in
advance of the station issuing the order.
If it were being restricted at
the station where the order was issued, using the single form would be just
as effective as a 31 order. Regardless of whether the single or dual system
is used, the importance of properly issuing, repeating, interpreting, and
executing orders remains the same.
When a train order is written, the kind of message it contains places it
in one of a number of definite categories, each identified by letter
designators. These show that the order conforms to rules having a similar
designator. All two-letter ones begin either with the letter "S" for single
track or "D" for double track. All single-letter ones apply to both single
and double track.
To illustrate how every train order falls into a definite category, the
following explanation is given. A DA form 55-203 is a train-order form, and
whenever a message is written on it, it becomes a train order.
message should advise one train to meet another, it becomes, in
classification terminology, a meet order.
Technically, the order is now
designated a form S-A order because it fixes a meeting point--something that
can occur only on a single-track line. The "S" denotes the single track and
the "A" identifies the order as being a meet order.
however, are neither printed nor written on the train order. They are used
merely as a quick reference to describe the type of instructions contained
in the order.
Form S-H describes a train order applying to a work extra
operating on single track.
Similarly, form D-M indicates a train order
annulling part of another train order on double track, the letter 'D"
applying to the track and the letter "M" denoting the partial annulment. A
train order with a single-letter designator, such as form F, applies to
single or double track.
The numerous other designators for train orders,
with specific examples, are discussed in detail in the following paragraphs.
The form S-A train order fixes meeting points for opposing trains on
single track. Typical examples are: