On 2010-08-20, David Cantrell wrote:
On Thu, Aug 19, 2010 at 09:48:11AM +0000, d wrote:
Surely it has some sort of handbrake? How else could it be parked safely
for long periods when the air will have all leaked out?
Uh, aren't railway brakes held *off* by vacuum, as opposed to being held
*on* by air?
Vacuum brakes are held off by the vacuum, if the air gets in they go on.
Air brakes are held off by the air pressure, and if the air gets out
they go on.
Both fail-safe, unless you try to mix them in the same train (in which
case you have to treat one lot as unbraked - there were rules about it).
Is there anywhere other than Britain where both were in use on the same
railway other than as a short transition period?
Eric