Brake Tests

48 Standard for Brake: Operation. ,_POWER Cannot be Changed Without To Show That the Emergency BRAKING POWE EXCEPT BY Some One of Changing the Service Braking Berow THE THREE METHODS EXPLAINED BELOW. 104. To handle trains without great risk of shocks, to minimize sufficient degree of latitude for the ecimeric application’s on different the bad effect of the time lapse en. that the retarding vehicles, and for adverse conditions incations be obtained gradually force developed during sc . low. This latter is a necessity, and that the maximum ecomparative baut also to keep the risk of wheel not only for the reasons g aD’nlications, and to insure a reserve sliding at a minimum for service applications of sufficient additional force for sreruretor service applications (that • 105. Ninety percent h the a herally accepted limit (and is the is, ordinary stops) all the roads in this country), and the standard today for pra srirnich this is spread for a proper degree of flexi- ante fgeduuincs, and the time in which this is done is seven seconds. 106. With these three factors accepted, any increase for emer- gency brake applisations air onal brake piston area. (3) Additional pressure carried, reservoir volume (2) By additional brake piston area. All these refer to the emergency brake applications only. (Of course, a compromise with any two or all three of these methods may be made.) , . :1 L 1 lesion and |07 These have been the underlying principles of brake design and installation for the past forty years, and practically all its philosophy is contained therein, as far as brakes for passenger cars are concerned. 108 To answer the question, which naturally occurs to one W y not change this standard since it has been in existence for 40 years?— It is asserted that this standard is as necessary for present conditions as it was for those for which it was designed. Brake applications are more frequently required, trains longer and the vehicles heavier. Con- more gradually than at present, unless simtiltaneon is assured by electric transmission. FUNCTIONS TO BE PROVIDED IN AN ADEQUATE AIR BRAKE MECHANISM. 109. The fundamental principles outlined in paragraph 9ft establish the limits to which the design tarectain functions and operating form. Within these limitations there a