SIDING. A track auxiliary to the main track for meeting or passing trains.

SIGNAL ASPECT. The appearance of a fixed signal conveying an indication as viewed from the direction of an approaching train.

SIGNAL INDICATION. The information conveyed by the aspect of a signal. SINGLE TRACK. A main track on which trains are operated in both directions.

SPEEDS. Medium Speed: A speed not exceeding forty miles per hour.

Restricted Speed: Proceed prepared to stop short of train, obstruction, or switch not properly lined and to look out for broken rail not exceeding twenty miles per hour.

Slow Speed: A speed not exceeding twenty miles per hour.

With Caution: To run at reduced speed, according to conditions, prepared to stop short of a train, engine, car, misplaced switch, derail or other obstruction, or before reaching a stop signal. Where circumstances require, train must be proceeded by a flagman.

SPRING SWITCH. A switch equipped with a spring mechanism arranged to restore the switch points to normal position after having been trailed through.

STATION. A place designated in the timetable by name.

SUBDIVISION or DISTRICT. A portion of a division designated by timetable.

SUPERIOR TRAIN. A train having precedence over another train.

TIMETABLE. The authority governing the movement of trains subject to the rules. It contains the classified schedules of regular trains, and special instructions.

TRAIN. An engine or more than one engine coupled, with or without cars, displaying markers.

TRAIN OF SUPERIOR CLASS. A train given precedence by time table.

TRAIN OF SUPERIOR DIRECTION. A regular train given precedence in the direction specified by timetable as between opposing trains of the some class.

TRAIN OF SUPERIOR RIGHT. A train given precedence by train order.

TRAIN REGISTER. A book or form used at designated stations for registering signals displayed, the time of arrival and departure of trains and such other information as may by precribed.

YARD. A system of tracks within defined limits, other than main track and siding, provided for the making up of trains, storing of cars and other purposes, over which movements may be made without train order authority, but subject to direction of a yardmaster, if on duty, and such rules, instructions and signals as may be prescribed.

YARD ENGINE. An engine assigned to yard service.

YARD LIMITS. The territory between signs placed adjacent to main tracks to designate the points between which engines may operate on main track without train-order authority or timetable authority, and within which limits engines and certain trains are restricted in their movement on all tracks.