A competition to find a safe and reliable form of train braking held in 1875 at Newark, Lincolnshire, UK, showed two clear winners, the air brake, invented by George Westinghouse of the USA and the vacuum brake, of which there were then two examples. Both required a pipe running the length of the train which was used to control the operation of the brakes on every vehicle. Both were controlled from a valve on the locomotive.
The principle of the two systems was the same. When the pipe was charged with compressed air or with a vacuum induced in it, the brake was released. When the pressure or vacuum was lost, the brake applied. Both systems used a cylinder on each vehicle which contained a piston connected to the brake shoes or blocks through rigging - a system of rods and levers.
The air brake was the clear winner in terms of stopping power and became widely used around the world but the vacuum brake was simpler and cheaper and was eventually adopted by most of the major railway companies in Britain.
The air brake was often called the Westinghouse Brake after its inventor even though many variations of it were and still are, built by other suppliers.