The Montgomery advertiser., 1907-10-14
BRAKES IMPORTANT
SOMETHING OF NEW APPARATUS
 ON TRAINS.
Phfiadelphia Railroad Man ExpInfnw some ef the Pecuiiarities of the
 Contrlvance and How 1t
 W0rks--S0metfues

90 important are the airbreakes on railroad trains nowadays that fire- man seeking promotion is examined
 more rigidly in regard to his knowl- edge of the apparatus governing them than as to his understanding of. the operation, of a locomotive. said the raiiroad foreman of engines on one of the big railroads running into this city, says The Philadelphia North Ameri- can.
 Moreover the examination on the air Is harder to pass than on the en- zine itself for the ordinary fireman. It IS absolutely necessary that each new engineer shall know all about the working of the airbrakes and their erect upon short and long trains un- der all sorts of conditions and until he gains this knowledge there Is no chance of his getting an engine
 The introduction of the emergency brake is largely responsible for this state of affairs for this invention, use full as 1t has been Is productiveof mis- chief.
 "In the early days of the airbrake, when the straight air system was used, the whole apparatus consisted of main reservoir on the engine, with a single connection with all the brake cylinders back through the train. When the engineer wanted to apply the brakes he turned the handle of three way cock in the cab. which allowed the air pressure from the engine res- ervoir to rush back though the train. and the afr filled one brake cylinder after another. forcing the brake shoes against the wheels. This old system had many weak points. One of these was that in a long train the air pres sure in the reservoir was not great enough to fill the cylinders throughout the train with enough pressure and gave slow acting brake of low power.
 "B1t the most vital defect was that if train was running down hills say, and hose connection broke on any part of the train the engineer was helpless. and nothing would prevent E bad wreck except the best luck or the prompt application of the hand brakes.
 Then automatic brakes were intro-. duced, which did away with both of these failings. In this system an air tank or reservoir is placed on each car alongside of each brake cylinder. This tank is filled with an air pressure from the engine and is controlled by a triple valve attached to the brake cylinder. This valve has three functions--tt re- leases the air from the auxiliary reser- voir on each car to the brake cylinder when applying the brakes, then allows the air to escape when the brake Is to be released. and also opens a hole through which the air pressure from the engine can once more charge the auxiliary reservoir.
 Now with this system, when the en- gineer wants to put down the brakes. instead of turning on the air, as mat ter of fact he draws 1t off The pres sure in the reservoir of each car being, say. 70 pounds on one side of the slid- ing valve and an equal pressure being on the engine side, the valve remains stationary. but when the engineer ale lows a certain amount of air to escape, this action, weakening the pressure on the engine side, causes the greater ,ressure in each car tank to force out each sliding valve, which as 1t moves exposes an entrance to each Drake cylinder, and simultaneously the air rushes into each n-ake eymnosr anu ca uses the application of all the brakes. This device has done away with all danger of a train running away. for fine moment hose breaks the pressure m inc engine side escapes and thus causes all the brakes to go down auto maticalIy.
 ."This brake has worked successfully in afmostN every respect and the en- rineers have mastered It's workings without much trouble. Then came inc emergency brake. which supplied the former remaining defect by pro- ducing an instantaneous and tremen- dous check. But with the emergency brake mas come a lot of complicated apparatus that has to be thoroughly understood. theoretically and practtcal- ly, by the engineers.
 gro put on the emergency brake the engineer throws over his air lever as far as 1t will go with one quick move ment. This lets out every bit Of pres sure in the train line that Is holding each valve in the ear reservoirs. Find ing no resistance the air from the car reservoir drives out the sliding valves as far as it will go, the great pres sure forcing it further than when an ordinary service application is made and this. discloses at once not only the whole of the entrance port to the brake cylinder. but also another openins IsadInr to Nthe pressure from the en- zine. At the bottom of the second