Brake Tests

233 curves. This curve is referred to four different scales, designating thousands of foot pounds per second, horse-power, total B. t. u.’s per second, and B. t. u.’s per brake shoe per second. The constant re- lation between these four scales is obvious. 436. These power-time curves are of particular interest in the study of the rate at which energy must be absorbed by the brake shoes during the. progress of the stop, as will be discussed in Chapter VII. Actual and Estimated Stops. A Summary of General Results with a Twelve CAR Train. 437. The following table of emergency 12 car train stops from 60 miles per hour summarizes the stops obtained during the road tests and shows briefly the gain in stopping distance to be obtained by the use of clasp brakes and the UC pneumatic or electro-pneumatic equip- ment. Brake Rigging Brake Shoes Air Brake Equipment Nominal Braking Power Stop Best Ava. Standard_ Plain .. ..... PM 113 1659 1677 Standard-------- Flanged PM 113 1453 1453 No. 1 Clasp.. No. 2 Clasp. Plain UC Pneumatic.. .... 125 1405 1443 Plain UC Pneumatic 125 No te sts. UC Electro-Pneu- No. 1 Clasp. Plain matic 125 1338 1339 No. 1 Clasp. Plain UC Electro-Pneu- matic 150 1157 1204 No. 2 Clasp. Plain UC Electro-Pneu- matic 125 1317 1332 No..2 Clasp.. Plain.. UC Electro-Pneu- marie 150 1097 1145 No. 3 Clasp... Plain UC Electro - Pneu- matic (Estimated) 125 1055 No. 3 Clasp.. Plain.... . . .. UC Electro - Pneu- Flanged matic (Estimated) UC Electro - Pneu- 150 965 No. 3 Clasp... matic (Estimated) UC E lectro - Pneu- 125 935 No. 3 Clasp... Flanged matic (Estimated) 150 860