THE WESTINGHOUSE AUTOMATIC AIR-BRAKE.
To overcome this line of weakness, the Westinghouse automatic air-brake was invented. Where good station signals are in use, it has long been accepted as an axiom among railway authorities, that a signal must be constructed so that it will indicate danger when any accident happens to its mechanism. This principle was brought into practical application in the Westinghouse automatic air-brake. When any thing goes wrong with the brake apparatus, its tendency is to apply the brake automatically. A break in a pipe makes the brake fly on. Each car carries a supply of compressed air sufficient to apply its own brakes several times. By the new arrangement, the brakes on all the cars are applied almost simultaneously, and instantly after the engineer turns the handle of his stopping-valve. The brakes are applied by decreasing the pressure in the pipes; so the breaking in two of the train, or the fracture of an air-pipe or coupling, sets the brakes on all the cars on the train, whatever side of the break the cars may be on. That in itself is an invaluable feature in a continuous brake, and prevents cars from acting as battering-rams upon each other in cases of derailment.