In message . li, at
15:24:48 on Sat, 11 Sep 2010, Tom Anderson
remarked:
If we accept that stopping at a red is an acceptable part of the safety
mechanism, why can't we also accept that stopping at the absence of a
green, or the absence of any signal, is?

Which goes back to the route knowledge people have dismissed a bit
prematurely, earlier in the thread.

Anyway, if a train has come out of the platform at the top, it's a bit
obvious that if should be taking the x-over to get to the westbound
track. http://goo.gl/maps/HuzB

And it's only about 300 metres to West Ham station, so the other train
must have been well west of there (maybe at Bromley-by-Bow station?).
--
Roland Perry

"Alan Ben It" wrote in message
...

It was the equipment that was faulty.The points moved when they
shouldn't have. The failsafe of having points set and locked with a
green signal (in this instance) failed..

Presumably the fact that the Plaistow bay was in normal passenger use by
Friday (or earlier - that's when I saw it in normal use) suggests that
whatever the fault actually was it was immediately fixable. Anything at all
unpredictable and trains still wouldn't be running ...

However it did occur to me that they are still some way through the
installation of the new central turnback siding between West Ham and
Plaistow. Presumably that will be requiring significant changes to the
interlocking in the whole area. I believe that it will become the normal
reversing point for short workings, ie pax will be tipped out at West Ham,
but it is also obvious from the installed track layout that it will be
accessible from both ends - so there are at least 6 new sets of points in
the area between the two stations.

But, IF the final design allows for entry to the central turnback siding
from the Plaistow bay, I'd be looking at the stage they'd got to in the
modifications...

(I am not a signalling engineer though, corrections welcome...)

Paul S

In article , (Roland
Perry) wrote:

In message . li,
at 15:24:48 on Sat, 11 Sep 2010, Tom Anderson
remarked:
If we accept that stopping at a red is an acceptable part of the safety
mechanism, why can't we also accept that stopping at the absence of a
green, or the absence of any signal, is?

Which goes back to the route knowledge people have dismissed a bit
prematurely, earlier in the thread.

Anyway, if a train has come out of the platform at the top, it's a
bit obvious that if should be taking the x-over to get to the
westbound track. http://goo.gl/maps/HuzB

Good grief! The bay exit even has a sand drag to protect it and they
manage this error!

--
Colin Rosenstiel

wrote in message
...

Good grief! The bay exit even has a sand drag to protect it and they
manage this error!

The sand drag is to stop a train attempting to leave the bay siding onto the
eastbound track though, it doesn't protect the crossover points, which are
the third and fourth of four sets of points over which the train would
travel from the bay to the westbound line.

Paul S

In article ,
(Paul Scott) wrote:

wrote in message
...

Good grief! The bay exit even has a sand drag to protect it and they
manage this error!

The sand drag is to stop a train attempting to leave the bay siding
onto the eastbound track though, it doesn't protect the crossover
points, which are the third and fourth of four sets of points over
which the train would travel from the bay to the westbound line.

Yes, I realise that but most bay platforms don't have even that
protection, Putney Bridge for example.

--
Colin Rosenstiel

In message ,
writes

I tentatively think this focus on the lack of signals is a bit
misleading. Ultimately, all safety on non-ATO lines depends on
drivers correctly responding to signals (barring tripcocks - am i
right i thinking these are only present at a fraction of signals?).
If we accept that stopping at a red is an acceptable part of the
safety mechanism, why can't we also accept that stopping at the
absence of a green, or the absence of any signal, is?

Tripcocks are present at all home signals on LUL lines.

You meant to say:

Tripcocks are present at all stop signals on LUL lines.

Didn't you?
--
Steve Fitzgerald has now left the building.
You will find him in London's Docklands, E16, UK
(please use the reply to address for email)

In article , ] (Steve
Fitzgerald) wrote:

In message ,
writes

I tentatively think this focus on the lack of signals is a bit
misleading. Ultimately, all safety on non-ATO lines depends on
drivers correctly responding to signals (barring tripcocks - am i
right i thinking these are only present at a fraction of signals?).
If we accept that stopping at a red is an acceptable part of the
safety mechanism, why can't we also accept that stopping at the
absence of a green, or the absence of any signal, is?

Tripcocks are present at all home signals on LUL lines.

You meant to say:

Tripcocks are present at all stop signals on LUL lines.

Didn't you?

Yes. I wondered whether I'd got it wrong when I wrote it. I meant to
exclude distant signals.

--
Colin Rosenstiel

On Sat, 11 Sep 2010, Steve Fitzgerald wrote:

In message ,
writes

I tentatively think this focus on the lack of signals is a bit
misleading. Ultimately, all safety on non-ATO lines depends on drivers
correctly responding to signals (barring tripcocks - am i right i
thinking these are only present at a fraction of signals?). If we
accept that stopping at a red is an acceptable part of the safety
mechanism, why can't we also accept that stopping at the absence of a
green, or the absence of any signal, is?

Tripcocks are present at all home signals on LUL lines.

You meant to say:

Tripcocks are present at all stop signals on LUL lines.

Didn't you?

Naturally.

Does 'stop signal' mean 'signal capable of telling a train to stop', ie
anything that can go red, as opposed to route indicators etc? If so, i
hadn't realised that, i stand educated, that's a very good thing, and i'm
surprised there wasn't something along those lines protecting the
wrong-way move that was possible here, some sort of always-on tripcock
alongside the board saying YOU ARE GOING THE WRONG WAY.

tom

--
Give the future a chance!

In message ,
writes

Tripcocks are present at all home signals on LUL lines.

You meant to say:

Tripcocks are present at all stop signals on LUL lines.

Didn't you?

Yes. I wondered whether I'd got it wrong when I wrote it. I meant to
exclude distant signals.

We don't have a concept of distant signals on LUL, only stop signals and
repeaters where sighting is restricted.

There are of course station starters (as far as I know at every station
but I'm sure someone will come along and tell me otherwise) and approach
signals to stations (known as outer, intermediate and inner home
signals). Long sections between stations are also split up into
sections with running signals (usually automatic). The key point is
that they are all stop signals (ie can show a red aspect) and as such
have an associated train stop. A repeater only being able to show a
green or yellow aspect does not have a train stop.

I think the point that has been made in this discussion (I've avoided
comments due to where I work) is that the train in question was routed
where it shouldn't have been but with normal signals exiting the sidings
and as such the driver would then have no signals to observe (and thus
no associated train stop to trip the train). I can't disagree with the
observation that the driver's route knowledge should have told them that
something was not right and I believe from the initial RAIB report this
is what happened and the driver realised and stopped the train.

I look forward to seeing the full report if the RAIB to find out what
lessons can be learned for future safety.
--
Steve Fitzgerald has now left the building.
You will find him in London's Docklands, E16, UK
(please use the reply to address for email)

In message . li, Tom
Anderson writes

Tripcocks are present at all home signals on LUL lines.

You meant to say:

Tripcocks are present at all stop signals on LUL lines.

Didn't you?

Naturally.

Does 'stop signal' mean 'signal capable of telling a train to stop', ie
anything that can go red, as opposed to route indicators etc? If so, i
hadn't realised that, i stand educated, that's a very good thing, and
i'm surprised there wasn't something along those lines protecting the
wrong-way move that was possible here, some sort of always-on tripcock
alongside the board saying YOU ARE GOING THE WRONG WAY.

Basically yes. Of course a route indicator will always have a stop
signal with it (as in a "you can now go and you are going to go this
way" signal).

If a line is not intended for bi-directional running (as it isn't in the
case under review) there is no need to provide signals for a route that
isn't, in normal circumstances, able to be used. I say normal
circumstances as there is always the possibility of doing a Wrong
Direction Move, however in the case of a WDM there is paperwork involved
and a whole safety procedure to follow so it isn't something that's done
lightly. I've never done one in anger in 9 years.

One additional item of protection that has been provided after some
incidents in the deep and distant past is fixed red lights as a reminder
at strategic places where an unusual move might possibly be made. I am
aware of at least one at Kings Cross WB Picc at the tailwall end that
has an associated train stop. The train stop automatically lowers when
a train approaches from the correct direction to avoid the train being
rear tripped. It then rises again as the train is fully berthed so that
any attempt to change ends and drive the other way will result in the
train being front tripped. I couldn't possibly comment on whether this
move has been attempted in the past whistles innocently (No! not me
)
--
Steve Fitzgerald has now left the building.
You will find him in London's Docklands, E16, UK
(please use the reply to address for email)