Brake Tests

34 69. The original intention was to change as many brake shoes each day as would be necessary to keep them in a umform condition throughout the tests. It was found in testing the standard (single shoe) brake, that this scheme could not be followed, on account of the large number of shoes which had to be replaced after tests at high speed and braking power with this type of rigging. onseque y thereafter the brake shoes were only changed when necessary. Station Stops. 70. From time to time special tests were made with PM air brake equipment, with UC air brake equipment and with UCan PM air brake equipment mixed in various ways in e ram. tests were regular service application station stops, or e pu p of observing the action of the UC air brake equipment either alone or mixed with the PM equipment, the train being handled by the • 1 Records were taken of the brake cylinder engineman in the usual way. Records 1:1 : 1 the results of these tests are described in pressure on each car and the results o detail in Chapter III. Standing Tests. 71. Several tests were made while the train was standing in , . - features of the brake mechanism, order to demonstrate various operative featur .1 These tests were made at times when it was impossible to ma e running tests. Organization. 72. One hundred and sixty (160) observations were taken on each regular test requiring an organization of forty-four observers, dis- tributed as shown on the organization chart (Fig. 21).