Air Brakes and Train Handling Rules - Alaska Railroad

“B” End (of car)The end where the hand brake is located, unless otherwiseidentified.GlossaryBack-Up Valve or HoseA device, either portable or permanently connected to the brakepipe, that controls brakes from the car it is attached to. Thedevice can be used to apply the brakes with a service or emergencyapplication.BleedVenting air pressure to the atmosphere.Blended BrakingUsing automatically controlled mixed air and dynamic braking atthe same time to provide a retarding force on cars and locomotives.Brake Cylinder Release Valve (bleed valve)The valve that initially bleeds brake cylinder pressure. If heldopen, it will bleed auxiliary and emergency reservoir pressures.Brake PipeThe pipe, angle cocks, hose, and hose couplings that distributecompressed air throughout the automatic brake system.Brake Pipe GradientThe difference in brake pipe pressure between the locomotive (orsource of supply) and the rear car of the train. Brake pipe gradientsmay be:Normal Gradient: The gradient that exists when the system isfully charged.False Gradient: The temporary gradient that exists when thesystem is less than fully charged (for example, the exaggerateddifference between the head end and rear end after a release).June 1, 1996 ARRC Air Brakes and Train Handling Manual G-3