194 



TRIPLE VALVES 



twentieth car. This shows why the slack in a train equipped 

 with K triples gives so much less trouble from bunching and 

 recoiling than it does in a train of H triples. 



Standing Tests. The time required to release brakes on an 

 eighty-car train, equipped with H and K triple valves and 

 standing, is shown in Fig. 7. These curves show that all 

 the brakes having K triple valves released at practically the 

 same time, in approximately from 14 to 16 sec. The brakes 

 having H triples, however, were very ununiform; the first 



brake released in 4$ sec., whereas the last brake required 40 

 sec. to release, a difference of 35j sec. This shows why it 

 is impossible to release brakes at slow speeds with H triples 

 without danger of breaking in two, whereas the danger is 

 practically eliminated where K -triples are used. 



Running Test. The distance required to stop, from different 

 speeds, trains equipped with H, K, and mixed H and K triple 

 valves, when a 15-lb. reduction is made, is shown in Fig. 8 

 and in the accompanying table, 



