HAND BRAKE. A device mounted on railcars and locomotives. It provides a means for
applying brakes manually, without air pressure. Common types include vertical wheel, horizontal
wheel and lever type, so named because of the configuration or orientation of their operating
HERO. An acronym that stands for Hazards of Electromagnetic Radiation to Ordnance.
HAZARD. Any condition that may cause an accident or contribute to the severity of an accident.
HAZARDOUS MATERIAL. Any material which poses a hazard. Examples of hazardous
materials are explosives, poisons, flammable liquids, corrosive substances, and oxidizing or
radioactive materials. When used with respect to lading in transportation vehicles, the term
identifies the lading as subject to specific safety requirements.
HOT BOX. Overheated roller or journal bearings.
IDLER CAR. Usually a flatcar used in the transportation of a long article or shipment, which
extends beyond the limits of the car carrying the shipment; the "idler" being a car on which the
shipment or article does not rest, but overhangs.
INTERCHANGE. The transfer of commercial railcars from one railroad to another at a
common junction point.
INTERCHANGE RULES. A set of regulations adopted by the Association of American
Railroads governing the care and handling of freight cars operating in interchange service.
JOINT. A fastening designed to unite the abutting ends of contiguous rails.
JOINT BAR. One of two steel bars used to join rail ends together to form continuous track.
Sometimes called "angle bar".
JOINT OPERATION. Trackage supporting operation of two or more railroads but controlled
by one source.
JOURNAL BOX. The metal housing on a plain bearing truck which encloses the journal of a car
axle, the journal bearing and wedge, and which holds the oil and lubricating device.
JOURNAL BRASS. Another term sometimes used when referring to a plain journal bearing.
KNUCKLE. The pivoting hook-like casting that fits into the head of a coupler and rotates about
a vertical pin to either the open position (to engage a mating coupler) or to the closed position
(when fully engaged).
KNUCKLE PIN. The steel pin holding the knuckle in the head of the coupler.
LAP. A braking position on certain locomotive automatic brake valves which retains the brake
pipe pressure selected by the operator.