TRIPLE VALVES 159 



FREIGHT-BRAKE TRIPLE VALVES 



DEVELOPMENT OF FREIGHT TRIPLE VALVE 



The original idea of providing a system of brakes that 

 could be applied to all the cars of a train and be under the 

 direct control of the engineer was suggested to George H. 

 Westinghouse in 1866 by a collision between two freight trains. 

 In its beginning, therefore, the brake was regarded merely as 

 a safety device and as such it was brought into use and 

 developed. 



The first air brake, namely, the straight-air brake, was 

 applied to a train consisting of a locomotive and four cars. 

 On the first run of this train, the engineer, by a prompt appli- 

 cation of the brakes, prevented what would likely have been 

 a serious accident had the train been equipped with any 

 other brake then in existence, thus demonstrating the value 

 of the air brake as a safety device. The control of the train 

 equipped with the straight-air brake was so superior to the 

 control that could be obtained by means of any other brake 

 then in use that the idea of using the brake to control a train 

 made up of more than four cars suggested itself. Accordingly, 

 in September, 1869, a six-car Pennsylvania Railroad train was 

 equipped with the air brake, and in November of the same 

 year a ten-car train was thus equipped. As the brake in most 

 general use at that time was a cumbersome chain brake 

 applicable to only four- or five-car trains, the success of the 

 air brake in handling ten-car trains at once made it valuable 

 as a dividend earner. The earning power of the air brake 

 consisted in its ability to handle longer and heavier trains at 

 higher safe speeds than was possible with other brakes then 

 in existence. 



The adoption of the straight-air brake by a number of the 

 leading railroads, on which it was pressed into general service, 

 eventually brought out the serious defects of the air brake 

 and made a further development of it necessary. This resulted, 

 in 1872, in the invention of the plain automatic brake, the triple 

 valve of which made possible the automatic brake of the present 

 day. 



