On Sat, 21 Aug 2010, Neil Williams wrote:

On Fri, 20 Aug 2010 19:46:24 +0100, Tom Anderson
wrote:

The weakness, of course, is the reservoir. If it isn't filled (eg a train
has been parked for ages), or it runs out (eg a train has parked
recently), or it leaks or is vented by mistake, you've lost your ability
to apply the brake. I don't know how this is dealt with - i would guess by
making the reservoir quite large and very reliable (and it is, after all,
just a big tank with a pipe coming out of it)

Part of it is additionally that trains tend to run with more than one
vehicle (not always, I know), and each has its own reservoir. Thus, if
in a 6-car train 2 cars lose their braking system completely, it will
still stop.

True. That doesn't help with the parking-related cases, though, where all
the cars will eventually lose all pressure.

Maybe there's a parking brake for those cases. That wouldn't have been a
lot of use in the case of the runaway grinder, of course.

Exactly. The sort of thing that in nuclear power engineering is called a
scram - a last-ditch, absolutely foolproof, not necessarily recoverable,
way of stopping a runaway.

On the railway that's often handled off the vehicle by a set of catch
points, which are basically points that deliberately derail the train
and send it off into a sand drag or something. Not that useful on
LUL, though.

For engineering work, derailer ramps are often fitted at each end to
catch any runaway and stop it by sending it off the track in the same
sort of way.

Ah, ingenious.

Maybe that's something LUL should look at doing - though if it had
happened here the two engineering staff on the runaway might well not
have survived the experience.

A sobering thought.

tom

--
solvilvitur ambulando. copy a diamond shape, recording angel. .. ..

On 22 Aug, 13:57, Tom Anderson wrote:
On Sat, 21 Aug 2010, Neil Williams wrote:
On Fri, 20 Aug 2010 19:46:24 +0100, Tom Anderson
wrote:

The weakness, of course, is the reservoir. If it isn't filled (eg a train
has been parked for ages), or it runs out (eg a train has parked
recently), or it leaks or is vented by mistake, you've lost your ability
to apply the brake. I don't know how this is dealt with - i would guess by
making the reservoir quite large and very reliable (and it is, after all,
just a big tank with a pipe coming out of it)

Part of it is additionally that trains tend to run with more than one
vehicle (not always, I know), and each has its own reservoir. *Thus, if
in a 6-car train 2 cars lose their braking system completely, it will
still stop.

True. That doesn't help with the parking-related cases, though, where all
the cars will eventually lose all pressure.

Maybe there's a parking brake for those cases. That wouldn't have been a
lot of use in the case of the runaway grinder, of course.

Exactly. The sort of thing that in nuclear power engineering is called a
scram - a last-ditch, absolutely foolproof, not necessarily recoverable,
way of stopping a runaway.

On the railway that's often handled off the vehicle by a set of catch
points, which are basically points that deliberately derail the train
and send it off into a sand drag or something. *Not that useful on
LUL, though.

For engineering work, derailer ramps are often fitted at each end to
catch any runaway and stop it by sending it off the track in the same
sort of way.

Ah, ingenious.

Maybe that's something LUL should look at doing - though if it had
happened here the two engineering staff on the runaway might well not
have survived the experience.

A sobering thought.

LU trains in sidings often (used to) have "THIS TRAIN MUST NOT BE
MOVED" hung on the outside of the cab. Would that be because they had
chocks fitted or something?

In message
, MIG
writes
LU trains in sidings often (used to) have "THIS TRAIN MUST NOT BE
MOVED" hung on the outside of the cab. Would that be because they had
chocks fitted or something?
BR used to use metal flags on poles fitted to lamp brackets saying "NOT
TO BE MOVED" when there was a fitter or anyone else that might be out of
sight but working on an engine.
--
Clive

In message , at 19:18:56 on Mon,
23 Aug 2010, Clive remarked:
LU trains in sidings often (used to) have "THIS TRAIN MUST NOT BE
MOVED" hung on the outside of the cab. Would that be because they had
chocks fitted or something?
BR used to use metal flags on poles fitted to lamp brackets saying "NOT
TO BE MOVED" when there was a fitter or anyone else that might be out
of sight but working on an engine.

Almost every EMT train I get to St Pancras seem to have a red hexagonal
"not to be moved" sign attached above the driver's door as soon as it
arrives.
--
Roland Perry

On Aug 23, 11:51*pm, Roland Perry wrote:

In message , at 19:18:56 on Mon,
23 Aug 2010, Clive remarked:

LU trains in sidings often (used to) have "THIS TRAIN MUST NOT BE
MOVED" hung on the outside of the cab. *Would that be because they had
chocks fitted or something?

BR used to use metal flags on poles fitted to lamp brackets saying "NOT
TO BE MOVED" when there was a fitter or anyone else that might be out
of sight but working on an engine.

Almost every EMT train I get to St Pancras seem to have a red hexagonal
"not to be moved" sign attached above the driver's door as soon as it
arrives.

A regular feature of intercity trains at London terminals (and at the
other ends as well I think), the meaning of which I've idly pondered
many a time but never definitively deciphered.

"Mizter T" wrote in message
...

Almost every EMT train I get to St Pancras seem to have a red hexagonal
"not to be moved" sign attached above the driver's door as soon as it
arrives.

A regular feature of intercity trains at London terminals (and at the
other ends as well I think), the meaning of which I've idly pondered
many a time but never definitively deciphered.

In that context it could simply mean 'don't go until we've finished
disconnecting the water hoses from the train'?

Paul S

On Tue, Aug 24, 2010 at 12:15:39PM -0700, Mizter T wrote:
On Aug 23, 11:51=A0pm, Roland Perry wrote:
Almost every EMT train I get to St Pancras seem to have a red hexagonal
"not to be moved" sign attached above the driver's door as soon as it
arrives.
A regular feature of intercity trains at London terminals (and at the
other ends as well I think), the meaning of which I've idly pondered
many a time but never definitively deciphered.

I would assume it means that the honey wagon is attached or that staff
are busy re-stocking the buffet etc and would rather not get hauled off
to the sidings or, even worse, the north.

--
David Cantrell | even more awesome than a panda-fur coat

"The whole aim of practical politics is to keep the populace alarmed
(and hence clamorous to be led to safety) by menacing it with an
endless series of hobgoblins, all of them imaginary" -- H. L. Mencken