In article , I wrote:
Seven Sisters: you can only do south-to-north from platform 4. Either:

Checking an old rulebook, I have some amendments to make:

* no route indicator at VL6, forward to VL7, change ends, signal VL20
takes you over the scissors to VL19 which protects the entrance to
the southbound platform.
* right-hand indicator at VL6, forward over the crossover to a fixed red
light behind VL22A, change ends, signals VL22A and VL22B take you
straight to VL19.

This is correct, except that the fixed red is placed so that VL22A will
be mid-train and can be ignored.

North-to-south is harder but possible: into platform 5, change ends,
signal VL8 takes you on to the depot exit road, over the scissors, and
up to VL7.

This is wrong. VL8 doesn't have a junction indicator, but nevertheless
can clear for two routes: either to VL7 on the depot entry road (62
road) or to the fixed red on the depot exit road (63 road). VL22B also
doesn't have an indicator but can clear for routes to either platform 4
(northbound) or 5 (southbound). So the north-to-south reversal is done
by: into platform 5, change ends, VL8 takes you to the fixed red on 63
road, change ends, VL22B takes you over the crossover and into platform
4, change ends, depart normally (VL6 with left-hand indicator).

[*] VL20 is not shown as having a junction indicator. I'm assuming,
therefore, that the only route from it leads to VL19.

This is correct.

--
Clive D.W. Feather | Home:
Tel: +44 20 8495 6138 (work) | Web: http://www.davros.org
Fax: +44 870 051 9937 | Work:
Please reply to the Reply-To address, which is:

On 24 Nov 2005 16:12:45 -0800, "
wrote:

angry Southbound passengers
passengers angrily looking

Nobody is "mildly annoyed" these days....
--
Nick Cooper

[Carefully remove the detonators from my e-mail address to reply!]

The London Underground at War, and in Films & TV:
http://www.nickcooper.org.uk/

Clive,

Many thanks for your informative reply. Yes, I suppose, on reflection
there were 2 problems, which were probably unconnected. An unfortunate
coincidence.

Nick, I was not "angry", just reisgned to my fate as another victim of
what one expects nowadays on the Underground.

Paradoxically, I used the Underground (Fulham Broadway to St. James'
Park) every day of my secondary school and NOT ONCE was I late on
account of Underground problems beween 1976 and 1984! Much as I would
have wanted otherwise.....

Marc.

On 24 Nov 2005 16:12:45 -0800, "
wrote:

On Wednesday morning, at aboutn 9.50a.m. there was some sort of
Victoria Line problem on the Northbound line into Victoria - according
to a station announcer a train was due to "come out of a siding"
(somewhere between Victoria and Pimlico?) to be the next Northbound
train but there was a signal problem, and the line became blocked.

[snip]

Two questions for those "in the know":

1. Was it inevitable that there would be difficulty in the Southbound
train trying to travel North out of the Southbound platform? For
example, maybe this was impossible because the next following
Southbound train was in block and therefore preventing any other train
from "reversing" into its block, even if only to use the cross-over to
the Northbound? If so, why did they even attempt to do so?

I would say it was not inevitable that the attempt to run north from the
s/b platform would fail because of the failure at the sidings. The two
ends of the station should run independently of each other.

It sounds to me, and I cannot recall what was in the internal daily
report, that there was a second failure that then prevented the intended
recovery strategy from working. It is the most sensible strategy at
Victoria if you are in the position of having the two sidings out of
service to the south because you can't get trains back out on to the n/b
tracks.

There is no point in sending trains to Brixton because you will end up
with a huge jam and given past incidents about trains stuck in tunnels
great attention is now paid to ensuring trains do not become stuck
between stations.

2. How on Earth could such a localised problem on a section South of
Victoria effectively paralyse the entire line in both directions?
Aren't there procedures in place to allow, for example (as presumably
was attempted here), turning trains at Victoria and then continuing a
Victoria - Walthamstow service, cutting out the Brixton section?

The decision to suspend is often the logical consequence when somewhere
like Victoria fails. It is so crucial to the line's operation that you
have to suspend, get the power off and allow the repair staff on to
track to undertake repairs. The other issue is traction current
sections which may not align with where the turnbacks / crossovers are.
Therefore you may need to suspend over a larger area to get the power
off.

Another point is that while loads of people are inconvenienced when a
line suspends it does provide a level of certainty about travel options
- i.e. the line is NOT running rather than it "might, possibly be
running to somewhere on the line at some point in time". I know this
seems perverse if you want to use the line but at least you are "forced"
to think about using another route.

If it's any consolation I hate it when the Vic Line falls over like this
as it's the main tube line to get me home. I do have about 10
contingency routes "up my sleeve" so I can keep moving if the worst
happens.
--
Paul C


Admits to working for London Underground!

Hehehehe.... You hate it??

You want to right the IRFs......

Mal

"Paul Corfield" wrote in message
...
On 24 Nov 2005 16:12:45 -0800, "
wrote:

On Wednesday morning, at aboutn 9.50a.m. there was some sort of
Victoria Line problem on the Northbound line into Victoria - according
to a station announcer a train was due to "come out of a siding"
(somewhere between Victoria and Pimlico?) to be the next Northbound
train but there was a signal problem, and the line became blocked.

[snip]

Two questions for those "in the know":

1. Was it inevitable that there would be difficulty in the Southbound
train trying to travel North out of the Southbound platform? For
example, maybe this was impossible because the next following
Southbound train was in block and therefore preventing any other train
from "reversing" into its block, even if only to use the cross-over to
the Northbound? If so, why did they even attempt to do so?

I would say it was not inevitable that the attempt to run north from the
s/b platform would fail because of the failure at the sidings. The two
ends of the station should run independently of each other.

It sounds to me, and I cannot recall what was in the internal daily
report, that there was a second failure that then prevented the intended
recovery strategy from working. It is the most sensible strategy at
Victoria if you are in the position of having the two sidings out of
service to the south because you can't get trains back out on to the n/b
tracks.

There is no point in sending trains to Brixton because you will end up
with a huge jam and given past incidents about trains stuck in tunnels
great attention is now paid to ensuring trains do not become stuck
between stations.

2. How on Earth could such a localised problem on a section South of
Victoria effectively paralyse the entire line in both directions?
Aren't there procedures in place to allow, for example (as presumably
was attempted here), turning trains at Victoria and then continuing a
Victoria - Walthamstow service, cutting out the Brixton section?

The decision to suspend is often the logical consequence when somewhere
like Victoria fails. It is so crucial to the line's operation that you
have to suspend, get the power off and allow the repair staff on to
track to undertake repairs. The other issue is traction current
sections which may not align with where the turnbacks / crossovers are.
Therefore you may need to suspend over a larger area to get the power
off.

Another point is that while loads of people are inconvenienced when a
line suspends it does provide a level of certainty about travel options
- i.e. the line is NOT running rather than it "might, possibly be
running to somewhere on the line at some point in time". I know this
seems perverse if you want to use the line but at least you are "forced"
to think about using another route.

If it's any consolation I hate it when the Vic Line falls over like this
as it's the main tube line to get me home. I do have about 10
contingency routes "up my sleeve" so I can keep moving if the worst
happens.
--
Paul C


Admits to working for London Underground!

On Sat, 26 Nov 2005 18:54:55 GMT, "Mal"
wrote:

"Paul Corfield" wrote in message
.. .
On 24 Nov 2005 16:12:45 -0800, "
wrote:

If it's any consolation I hate it when the Vic Line falls over like this
as it's the main tube line to get me home. I do have about 10
contingency routes "up my sleeve" so I can keep moving if the worst
happens.

Hehehehe.... You hate it??

You want to right the IRFs......

Well I get to read enough of them in JNP land that I don't really want
to add in BCV as well.

--
Paul C


Admits to working for London Underground!

Thats terrible.....i meant write....... bugger!

Mal


"Paul Corfield" wrote in message
...
On Sat, 26 Nov 2005 18:54:55 GMT, "Mal"
wrote:

"Paul Corfield" wrote in message
. ..
On 24 Nov 2005 16:12:45 -0800, "
wrote:

If it's any consolation I hate it when the Vic Line falls over like this
as it's the main tube line to get me home. I do have about 10
contingency routes "up my sleeve" so I can keep moving if the worst
happens.

Hehehehe.... You hate it??

You want to right the IRFs......

Well I get to read enough of them in JNP land that I don't really want
to add in BCV as well.

--
Paul C


Admits to working for London Underground!