The leading tripcock will only hit a trainstop if the signal is being passed
at red, not usually done.

The rear tripcock is on the wrong side of the track to connect with the
trainstop.

So is that to imply that there's no tripcock-equipped lines that are
signalled for bi-directional working? Or if so, is there some
technical gubbins that will lower the "wrong-direction" cocks when a
train is running wrong line?

TIA

Matt

The most common instance of this, as was said in the original post is
when you have multiple units coupled together running over LUL lines.
Then you will have a cab with a tripcock fitted on the side of the
track the trainstop is raised on.

"M J Forbes" wrote in message
oups.com...
The leading tripcock will only hit a trainstop if the signal is
being passed
at red, not usually done.

The rear tripcock is on the wrong side of the track to connect with
the
trainstop.

So is that to imply that there's no tripcock-equipped lines that are
signalled for bi-directional working?

If there is (on the Met), Platform 2 at Amersham and Platform 5 at
Harrow on the Hill may be bi-di. I can't be sure about Amersham, but
i've seen A stock in platform 5 at harrow (Chiltern, london bound),
when on an Aylesbury bound train in platform 6, and pretty sure that
the platform 5 train was shown as for Rickmansworth.
Also, platforms 1 & 4 at Baker Street, and I think 2 and 3 are bi-di
as well.


Or if so, is there some
technical gubbins that will lower the "wrong-direction" cocks when a
train is running wrong line?


Can't answer that one.

Matt

On Tue, 19 Jul 2005 17:56:37 +0100, "Matt Wheeler"
wrote:

The leading tripcock will only hit a trainstop if the signal is
being passed
at red, not usually done.

The rear tripcock is on the wrong side of the track to connect with
the
trainstop.

So is that to imply that there's no tripcock-equipped lines that are
signalled for bi-directional working?

If there is (on the Met), Platform 2 at Amersham and Platform 5 at
Harrow on the Hill may be bi-di. I can't be sure about Amersham, but
i've seen A stock in platform 5 at harrow (Chiltern, london bound),
when on an Aylesbury bound train in platform 6, and pretty sure that
the platform 5 train was shown as for Rickmansworth.

As was demonstrated during the weekend closures for the Wembley Park
works, there is plenty of bi-directional trackwork to the west of
Harrow-on-the-Hill station, and trains can reverse east-to-west in
almost any platform. Platform 2 (the one you describe as 5) has
electric rails solely for this purpose.

On Tue, 19 Jul 2005 18:26:43 +0100, asdf
wrote:

snip
As was demonstrated during the weekend closures for the Wembley Park
works, there is plenty of bi-directional trackwork to the west of
Harrow-on-the-Hill station, and trains can reverse east-to-west in
almost any platform. Platform 2 (the one you describe as 5) has
electric rails solely for this purpose.

ISTR that platform always was electrified but more as a precaution
against the misrouting that occurs from time to time. Unlike e.g.
sending a Marylebone to Rugby train down the Uxbridge line, sending an
electric train down a non-electrified track takes a bit longer to
"undo".

"M J Forbes" wrote in message
oups.com...
So is that to imply that there's no tripcock-equipped lines that are
signalled for bi-directional working? Or if so, is there some
technical gubbins that will lower the "wrong-direction" cocks when a
train is running wrong line?

The back tripcocks remain operational at all times - indeed instances of
trains being "back-tripped" are quite common, mainly due to obstructions on
the line.

On bi-directional lines, trainstops reading in the wrong direction will be
automatically lowered as the train approaches, and will raise again when the
train passes to provide protection. There are still problems with certain
reversing movements, however...

As an example, if an 8-car train of A stock reverses eastbound in the Circle
Line platform at Baker Street, the sequence is as follows:-
1. Westbound starting signal cleared, train shunts forward far enough to
fit behind the eastbound starter (w/b starter change to red once front of
train passes it).
2. T/Op cuts out tripcock at that end, and changes ends.
3. Eastbound starting signal cleared and train departs east, rear trip
striking the now-raised trainstop at the westbound starter, but with no
effect because cut out.
4. Tripcock cut back in next time train driven from that end.

As can be seen, problems often arises not with the wrong-road starter, but
with other signals.

On 19 Jul 2005 04:52:40 -0700, "M J Forbes"
wrote:

The leading tripcock will only hit a trainstop if the signal is being passed
at red, not usually done.

The rear tripcock is on the wrong side of the track to connect with the
trainstop.

So is that to imply that there's no tripcock-equipped lines that are
signalled for bi-directional working? Or if so, is there some
technical gubbins that will lower the "wrong-direction" cocks when a
train is running wrong line?

There are (as I said earlier in the thread) a few places on LU where
trains can go in either direction, terminal lines being the most
obvious. At these locations the "wrong way" trip levers will be seen
to lower as a train approaches to prevent rear-tripping. IIRC High
Street Kensington is such a place possibly with some short stretches
of bi-directional track on the southern approaches. The same possibly
also applies to the two through Met main line platforms at Baker
Street if they are still signalled to cope with reversing trains.