Brake Tests

18 CHAPTER II. METHOD OF CONDUCTING TESTS. Train MAKE-UP and Equipment. 30. A train 1,040 feet long consisting of a pacific type locomotive and tender, of the K2. class, weighing in working order about 200 tons, and 12 P-70 steel passenger cars averaging about 61 tons each, was used during these tests. 31. It was the intention to use the same locomotive throughout the tests, but after test No. 622 it was found desirable to change loco- motives, the second locomotive being used to the end of the tests. 32. The standard Westinghouse No. 6 ET air brake equipment was used without any modification, on the locomotive, except that in some tests an auxiliary device was used which increased the braking power obtained during the early portion of the stop. (Chapters III and V.) Some changes were made in the tender brake rigging and trucks. These changes are explained in detail in Chapter IV. The weights, lever arrangements, per cent, of braking power, etc., for the locomotive and tender and cars are given on pages 318 to 321, inclusive. 33. All tests were made under road service conditions, except where otherwise noted, the air brake regulating devices on the loco- motive and cars being adjusted as follows:— Pump governor—Low pressure head 130 pounds. Maximum pressure head 140 pounds. Feed valve—110 pounds. El Distributing valve safety valve—68 pounds. 34. The cars were equipped with the present standard air brake apparatus (PM) and with improved type of air brake equipment (UC), these installations being so arranged that a complete change from the standard equipment (PM) to the new equipment (UC), having PM features only, or to the complete pneumatic features of the new equip- ment or to the new equipment with complete electrical control could be quickly made. In addition to the different air brake equipments tested, the cars and locomotive were equipped with an electro-pneu- matic train signal system. This was given no special attention, but was installed to show the advantages of this system which will be described in Chapter III. 35. In addition to our standard plain cast-iron brake shoes, which were used in most of the tests, several tests were made with flanged, slotted and half area shoes, all being of cast iron. Special care