Ballast – Selected rock material placed on the roadbed for the purpose of holding the track in line.

Cab – The space in the locomotive unit containing the operating controls and seats for the engine crew. Cab can also be located in select passenger cars, known as cab cars.

Conductor – Railroad employee in charge of the train.

Continuous rail – Rails of standard length which are welded together at the ends to form a single rail of a considerable length.

Coupler – A device located at both ends of all cars in a standard location to provide a means for connecting one rail car to another.

Deadhead – Train going from one location to another without taking on passengers.

Dispatcher – Employee responsible for directing and controlling the movement of trains.

Engineer – Operator of a locomotive.

Extra board – A list of unassigned employees available to work, normally in the place of the regularly assigned crew.

Flagman – An extra crewman used to flag rail traffic around construction sites.

Frog – A device made of rail sections that permits the wheels on one track to cross another rail of an intersecting track. Resembles an “X” or a frog with legs extended.

Gauge – The distance between the heads of the rails, measures at a point 5/8" below the top of the rails. Standard gauge in the United States and Canada measures 4 feet and 8.5 inches.

Grade Crossing – A crossing at the same level, either between track of different railways or between railway tracks and public crossings (highways and roads).

Hot Box – An overheated axle bearing caused by excessive friction between bearing and axle due to lack of lubricant or the presence of foreign matter.

Hot Box Detector – A wayside infrared sensing instrument used to identify overheated axle bearings, usually placed about every 20 miles.

Hours of Service Law – The Federal statute which provides that all train and engineer crews must be relieved of duty after 12 hours of continuous service.

Maintenance of Way Equipment – Equipment designed for working on tracks and railroad right-of-ways.

Rail – A length of track, usually 39 feet long.

Right of Way – In the strictest sense, land or water rights necessary for the roadbed and its accessories. However, it is now loosely used to describe property owned and/or operated over by a railroad.

Single Track – A main track upon which trains are operated in both directions.

Switch (Turnout) – A device consisting of two movable rails, necessary connections, and operating parts designed to turn a train from the track on which it is running to another track.

Train Order – A written mandatory directive governing the operation of trains that is issued by the train dispatcher.