During the first two years after it was invented, the Westinghouse brake made slow progress into practical application, except in the West. In the ancient State of Massachusetts, it was hardly known till the Revere accident happened near Boston. This was the case of a crowded road being operated without signals or brakes, except those of the most primitive description. A fast express train ran into the rear end of an accommodation train, killing twenty-nine persons, and severely injuring fifty-seven others. The engineer of the express train, while running at a speed of twenty-five miles an hour, saw the tail lights of the accommodation train when he was eight hundred feet away. He whistled for brakes, and reversed his engine; but the train could not be stopped.
The railroad superintendents throughout the conservative State of Massachusetts then received enlightenment respecting the existence of an efficient continuous brake in a vigorous fashion. The Revere accident conveyed its lessons in a terrible way, but they were effectual in convincing railroad managers that they could not afford to dispense with a brake that proved itself to be reliable.
WEAK POINTS OF THE ATMOSPHERIC BRAKE.
Although the atmospheric brake could, with light trains, make stops within the shortest distance it was desirable to stop trains with safety to the passengers and rolling stock, it possessed certain weak points which demanded remedy. In case of a train breaking in two,—an accident which frequently happens, especially on rough track,—there was danger of the engineer applying the brake without knowing that an interval existed between the cars, and allowing the rear end of the train to crash into the forward part. The signal given by the bell-rope breaking, had a tendency to lead to an accident of this character. Another objection to straight air was, that should derailment take place, or any accident happen that would rupture the pipes or their connections, the brake was rendered useless. These weak features did not interfere with the working of ordinary traffic; and as providing special appliances to meet cases of accident which are rare, does not generally receive much consideration, the brake might have been regarded as perfect enough for all practical purposes had it not failed to meet satisfactorily a condition of ordinary train service. As the length of trains was increased, it was found that the atmospheric brake was slow in action. When a long array of pipes and many cylinders had to be charged with air from the drum on the locomotive after the necessity for applying the brake became apparent, and before it would act, some seconds were required for the operation. Every additional car put upon the train increased the length of pipes and the cylinders to be filled, and so lengthened the time that elapsed between the instant danger was perceived and the time at which the brake began to perform its retarding work. The increase of time might be only a few seconds, but they would probably be priceless moments when an accident was impending.
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.
LIFE-SAVING VALUE OF THE AUTOMATIC BRAKE.
Every few days, notices get into the public prints relating how frightful accidents were prevented by the prompt action of the automatic air-brake. And hundreds of narrow escapes, where this brake proves the preventive of destruction to life and property, receive no record, and are known only to the employes connected with the operating of trains. To the men familiar with train service, to those who are intimately acquainted with the life-saving effected by the automatic air-brake, it seems surprising that railroads could have been operated without this or a similar appliance. They certainly were not operated safely without it.