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David Cantrell · August 20th 10, 10:47 AM posted to uk.transport.london

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?

That's fail-safe - lose power or burst a pipe and the vacuum goes away,
and the brakes go on. Of course, this doesn't help if you've
deliberately disabled the braking system, but I would expect the
operating procedures to only permit that if there is a hand-operable
braking system, even if it's just screwing a shoe down onto the wheels
and really ****ing up the wheels. I await the RAIB report with
interest. They're usually good reading as well as being informative.

--
David Cantrell | Hero of the Information Age

I remember when computers were frustrating because they did
exactly what you told them to. That seems kinda quaint now.
-- JD Baldwin, in the Monastery