160 TRIPLE VALVES 



The automatic brake was developed during the years 1872 

 and 1873, and it was so superior to all other forms of brake 

 that it was adopted as the standard for passenger-train service. 

 Up to that time no power brake was in use in freight service, 

 and the attempts to increase the length of freight trains 

 led to numerous accidents and break-in-twos, caused chiefly 

 by lack of proper train control. These accidents led to the 

 belief that the automatic brake could be successfully used in 

 handling long freight trains. To find out whether or not this 

 could be done, the Westinghouse Air Brake Company, in 

 1882, fitted up a fifty-car train with the plain automatic air 

 brake and took it over the Alleghany Mountains. Tests 

 made on this trial trip clearly demonstrated that the braking 

 power of this type of brake was sufficient to control the speed 

 of the train even on the heaviest grades. 



The success of the automatic air brake brought several 

 competitive brake systems into the field, and in 1885 the 

 Master Car Builders' Association appointed a committee to 

 investigate the relative merits of these brake systems as well 

 as to report on the feasibility of controlling a fifty-car freight 

 train by means of a continuous power brake, a point much 

 in controversy at that time. A series of tests with fifty-car 

 trains, known as the "Burlington tests," was begun in 1886 

 and completed in 1887. The Westinghouse brake and three 

 others were entered in these tests, which clearly demonstrated 

 that none of the brake systems could be successfully used in 

 every-day service on trains of fifty cars. The Westinghouse 

 brake worked satisfactorily in service applications, but in 

 applying it in emergency the interval between the application 

 of the brake on the first car and the last car was so long that 

 the shock caused by the rear cars running into the front cars 

 was terrific. 



This necessitated a modification of the plain triple valve 

 for fifty-car freight-train service. Accordingly, in 1887, the 

 quick-action triple valve was brought out. This triple was 

 applied to the fifty-car train, which had been left at Burling- 

 ton. Tests were made to try out the triples and they were 

 found to be so satisfactory by the railway officials and by 

 the persons conducting the tests that the train was sent on 



