AIR BRAKE. The braking system used on all railcars.
AIR BRAKE HOSE. The flexible hose at each end of a railcar which is threaded into the brake
pipe angle cock at one end, and has a glad hand fitting at the other end which engages with a
similar coupling on an adjoining car.
AMPERE. The fundamental unit of measure for electric current. One Ampere is defined as the
current that flows when a potential of one volt is impressed on a resistance of one Ohm.
ANGLE BAR. One of two steel bars used to join rail ends together to form continuous track,
(sometimes called "joint bar").
ANGLE COCK. A special type of 1-1/4" valve of either ball or plug design, located at both
ends of the brake pipe on locomotives and railcars and used to control admission of air to the
brake pipe on individual cars. The free end is angled at 45 degrees and is threaded to receive the
threaded end of the air hose.
'B' END OF CAR. The end on which the hand brake is located. Commonly used with "L" or
"R" to designate either the left or right side when facing the "B" end, i.e., "BL" or "BR," "AL" or
BALLAST. Angular crushed stone used for placement on the roadbed for the purpose of holding
the track in line to ensure it is properly surfaced. Distributes and transfers railcar loads from the
tie to the subgrade and provides for drainage.
BARRICADED SIDING. A siding within concrete or earth walls to contain hazardous material
BEARING, JOURNAL. The general term used to describe the load bearing arrangement at the
blocks of metal, usually brass or bronze, shaped to fit the curved surface of the axle journal, and
resting directly upon the bearing, with lubrication provided by free oil contained in the journal
box. Journal roller bearings are sealed assemblies of rollers, races, cups and cones pressed onto
axle journals and generally lubricated with grease. Vertical loads are transferred from the journal
bearing to the truck side frame through the journal bearing wedge (plain bearing design) or
through the roller bearing adaptor in roller bearing trucks.
BLEED. Remove air from a railcar brake system. ABD railcar brake valves allow the brake
cylinder to be bled while saving the air in the reservoirs on the car or, if desired, the entire car air
system can be bled. AB railcar brake valves bleed the entire system.
BLOCK. A length of track of defined limits, the use of which is controlled by block occupancy
BLUE FLAG. A blue signal (blue flag by day, a blue light by night), displayed at one or both
ends of the locomotive, car, train, or track indicating that workmen are in, on, under, between or
around the equipment. Equipment with blue flag protection shall not be moved or coupled into.