Tom Shreve Wrote:
-------------------------------------------------------
> The advantage to a vacuum brake system is that to
> create the vacuum, all you need is a venturi setup
> like an injector with no moving parts. The
> disadvantages are that it is almost impossible to
> get more than, say, 11 lbs of vacuum at sea level,
> much less at 5000 feet. Therefore a much larger
> brake piston is needed in order to apply enough
> force to brake the car. On most Narrow Gauge cars
> there just isn't enough room between the car body
> and the rail.
Almost spot on - the device you were thinking of is called an "Ejector". I'm familiar with Vac brakes but know little of air brakes other than the theory.
Gavin
Linslade
Bedfordshire
UK
Garratt Locomotives
[
www.beyergarrattlocos.co.uk]