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Ben. The original William, like the Pea had only a parking brake acting on one axle and with 20 children up you did not stand a chance of stopping in an emergency. I looked at the various systems on other club locos which were mechanical lever operated and efficiency depended on effort, (not much good to the juniors). Not wanting to break into the steam supply I came up with a simple electrical system (drwg attached) which works instantly, never needs adjusting and will stop me, fully loaded in a short distance. It works as follows:- If you look at the picture of my tender, you will see a lever on the side, at the front. Pulling the lever rearwards closes off a valve and makes the switch, starting the tyre compressor, the air has no where to go except to the cylinders and a relief valve maintains the pressure at 40-50 psi. When the gauge indicates 50, (almost instantly) the lever is released and the spring in the push switch pushes the lever away from the switch, breaks the circuit and stops the compressor. There is enough overlap in the valve for it to remain closed and hold the pressure for about 10 mins without operating again. to release, the brake the lever is pushed forward, opening the valve to atmosphere. My cyls operate on each tender bogie. The cyls are 1 1/2" bore x 1 1/2" stroke. The tyre compressor costr £5.00 and the battery £12.00 in the U.K. the rest is workshop. One way to do it, there are many more. Tom
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