THE STEAM LOCOMOTIVE 



system of brakes, such as those using steam as a work- 

 ing force, or systems of hand-wound springs; but Mr. 

 Westinghouse utilized compressed air, and from the 

 first his brakes proved effective. 



His first air brake, operated successfully in 1869, 

 was the "straight air brake'* type — one that has now 

 been replaced almost universally by the automatic. In 

 this brake system there was an air reservoir on the loco- 

 motive, and steam was used for making the compres- 

 sion. From this reservoir a line of gas pipe ran through 

 the cab of the engine beneath the tender and under 

 each car, the space between the cars being bridged by 

 rubber tubes and easily-adjusted couplings. This line 

 of pipe, called the train pipe, was connected near the 

 centre of each car with a cylinder which contained a 

 piston with a stem which acted upon the brake shoes 

 by means of a series of levers and connecting rods. 



In the cab, placed conveniently for the engineer, was 

 a valve by means of which he could cause the com- 

 pressed air to flow into the train pipe and thus act 

 upon the brake cylinders of the cars. This could be 

 done gradually for making a slow stop, or with full 

 force as the case required, and the brakes could be re- 

 leased by turning the valve to a point which opened a 

 vent and allowed the air to escape. 



The effect of this invention was revolutionary. 

 Stopping the train was no longer dependent upon 

 manual labor applied intermittently at different points, 

 but was placed entirely in the hands of the engineer 

 who applied the required power almost simultaneously 

 at all points along his line of cars. Thus the brake- 



[143I 



