In article , (Roland
Perry) wrote:

In message
, Colin
Rosenstiel
More a concept fault for tube tunnels. Not a problem with cut-and-cover
tunnels but then London's tubes aren't based on them.

Most of the "Underground" system is either above ground, or in
twin-track cut and cover.

Not in Zone 1 though.

--
Colin Rosenstiel

In article , Roland Perry
writes
[These are excusable when the tubes were originally designed for normal
working hours. I think we forget how little of life was 24x7 as
recently as 30 years ago. I could certainly drive from Cambridge to
Chelmsford at midnight and see no other car on the road. At some point
this changed radically - perhaps the tubes need to keep up.]

The answer, of course, is cost. Digging new crossover tunnels isn't
cheap. Signalling changes are cheaper, but is it a better way to spend
the money than running night buses instead?

--
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:

In message ,
Colin Rosenstiel writes
Most of the "Underground" system is either above ground, or in
twin-track cut and cover.

Not in Zone 1 though.

No, but being able to run 24x7 round the Circle, and on many of the
lines outside, would be much better than nothing.
--
Roland Perry

In message , Clive D. W. Feather
writes
Digging new crossover tunnels isn't cheap.

I wouldn't suggest new tunnelling.
--
Roland Perry

In article , (Roland
Perry) wrote:

In message , Clive D. W. Feather
writes
Alternate working requires a sufficiency of crossovers to switch
trains. The tube lines don't have these, in general.

A design fault, then.

There's also a problem with trainstops - they need to be lowered to
prevent a train running the wrong way from "back-tripping". Except
where bidirectional working is allowed (e.g. at termini) this isn't
designed into the signalling.

Another fault.

[These are excusable when the tubes were originally designed for normal
working hours. I think we forget how little of life was 24x7 as
recently as 30 years ago. I could certainly drive from Cambridge to
Chelmsford at midnight and see no other car on the road. At some point
this changed radically - perhaps the tubes need to keep up.]
--
Roland Perry

This will gradually change when new signalling systems come in, although
the shortage of crossovers will be the restriction. Come movable block
(joint) signalling, trains will just be able to reverse wherever they are
and go back the other way - a sort of signalled wrong direction movement.
Ideal during one unders, security alerts etc.

Roger

In article ,
Roland Perry wrote:
In message ,
Colin Rosenstiel writes
Most of the "Underground" system is either above ground, or in
twin-track cut and cover.

Not in Zone 1 though.

No, but being able to run 24x7 round the Circle, and on many of the
lines outside, would be much better than nothing.

There's not much point in Leytonstone - Epping running 24/7. Or
even Stratfor - Epping (although there is slightly more point in
the latter).

I agree about the circle, though.

--
You dont have to be illiterate to use the Internet, but it help's.

In message , Mike Bristow
writes
There's not much point in Leytonstone - Epping running 24/7. Or
even Stratfor - Epping (although there is slightly more point in
the latter).

You'd probably want to restrict it to Leytonstone on that end of the
line, and Ealing Broadway the other.
--
Roland Perry

Roland Perry wrote:
In message
, Colin
Rosenstiel writes
Most of the "Underground" system is either above ground, or in
twin-track cut and cover.

Not in Zone 1 though.

No, but being able to run 24x7 round the Circle, and on many of the
lines outside, would be much better than nothing.

True, but the starting point isn't nothing. It's the most extensive
night bus network in the world.
--
Richard J.
(to e-mail me, swap uk and yon in address)

On Thu, 20 May 2004, Roland Perry wrote:

In message , Mike Bristow
writes

There's not much point in Leytonstone - Epping running 24/7. Or
even Stratfor - Epping (although there is slightly more point in
the latter).

You'd probably want to restrict it to Leytonstone on that end of the
line, and Ealing Broadway the other.

Why is there not much point? What about people who live in Epping or West
Ruislip and want to get home late at night?

tom

--
In-jokes for out-casts

In article ,
Tom Anderson wrote:
Why is there not much point? What about people who live in Epping or West
Ruislip and want to get home late at night?

Where are they coming from? Leytonstone? Not likely. More likely
to be the West End - and the suggestion was not to run the tube
24/7 through that area.

Seems to be catering for the really small market of people who go
clubbing at Kirkdales, or who have already endured a long bus
journey.

--
You dont have to be illiterate to use the Internet, but it help's.