On Sun, 1 Jul 2007, Paul Terry wrote:

In message , John Rowland
writes

Paul Terry wrote:

I guess it would be possible for trains to reverse at Clapham Junction
and continue round the circle, but I imagine that it could produce all
sorts of operating problems.

I can't think of any, unless you mean "reverse *promptly* at Clapham
Junction and continue round the circle".

Clockwise and anticlockwise services would have to cross on the level just
outside the station if they were not to terminate at Clapham Junction.

There is another option - if trains didn't visit Clapham Junction at all,
they could go from Imperial Wharf to Wandsworth Road directly, without
reversing. I don't have a track map to hand, but ISTR that this can be
done without conflicting movements across other tracks.

Pathing on the ELLE should be easier, but it is likely that the line
will have to be shared with some sort of SLL service to Victoria, so
there is all sorts of potential for circle-line-like delays - breaking
the service at Clapham Junction should help mitigate that.

The other branch of the ELL will also share with all sorts of things in
the Croydon direction; performance pollution here would be able to spread
to the Clapham branch via the core, albeit probably not very strongly.

tom

--
Destroy! DESTROY! DEEEEEEE-STROY 2000 YEARS OF CULTCHAH!! -- Andrew

On Sat, 30 Jun 2007 15:24:18 +0100, "Paul Scott"
wrote:


"Paul Corfield" wrote in message
.. .

Circular services are only a problem when you try to run them with
inadequate infrastructure or schedules that are too tight - are that
would be why can't run them in this country then!

I believe thats the background to the T-cup proposals for the circle line
and H&C isn't it?

It may be but my point is that circular services can run properly if you
get non conflicting junctions and adequate signalling capacity. This is
what Berlin has got on its S Bahn and the service runs fine. The LU
proposals are an attempt to create reliability without the huge
construction costs of removing conflicting junctions of which there are
many on the Circle / District line.
--
Paul C


Admits to working for London Underground!

In article ,
Tim Roll-Pickering wrote:
Paul Terry wrote:

It should produce a more robust service if the trains *do* continue around
the circle, after a suitable wait... that way problems which affect the
clockwise can't affect the anti and vice versa.

I don't think that the Orbirail project will ever run a fully circular
service, because of the potential for serious delays (like the circle line
but infinitely worse).

Maybe not a complete circular service, but some through services running
across Clapham Junction would have clear attractions, especially as it would
reduce the interchange pressure and give passengers a better indication of
how long it will take to get to their destination. Back to back terminuses
aren't as attractive for passengers - look at buses where there are mancy
cases of two services on what is basically a single long route overlapping
rather than having all the changeover in one place.

That said I'm not sure where the natural terminuses for a reasonable service
running across Clapham are.

Moorgate Street and Victoria :-)

Seriously, the Inner Circle/District Line seems to work fairly well
with a varity of places to turn back ahead of congestion. Building a
straight-through platform and reversing crossovers at CJ might be a
good way to plan the EWNSLLines, as a way of limiting disruption whilst
enabling through journeys.

But should there be a travolator to reach the platforms ... ?

Nick
--
http://www.leverton.org/blosxom ... So express yourself

In message , Tom
Anderson writes

There is another option - if trains didn't visit Clapham Junction at
all, they could go from Imperial Wharf to Wandsworth Road directly,
without reversing. I don't have a track map to hand, but ISTR that this
can be done without conflicting movements across other tracks.

That is certainly true, but loss of connection at Clapham Junction
(Britain's busiest railway station) would be a serious loss and would
need the retention of the now popular Clapham-Willesden service, thus
restricting the viability of an 'orbirail' service that by-passed
Clapham Junction.
--
Paul Terry

In article ,
(Tom Anderson) wrote:

There is another option - if trains didn't visit Clapham Junction
at all, they could go from Imperial Wharf to Wandsworth Road
directly, without reversing. I don't have a track map to hand, but
ISTR that this can be done without conflicting movements across
other tracks.

Misses out a rather important traffic objective, though.

--
Colin Rosenstiel

Paul Terry wrote:

I don't think that the Orbirail project will ever run a fully
circular service, because of the potential for serious delays (like
the circle line but infinitely worse). Nothing's decided, AFAIK,
but clockwise services from Clapham Junction may terminate at
Stratford for the Olympics, and at Barking thereafter, although it
has also been suggested that they may (as at present) go no further
than Willesden Junction.

Where have you seen that suggestion? I thought that 8 tph on the North
London Line east of Willesden Junction was a key feature of TfL's
proposals in order to reduce overcrowding on the WJ-Stratford section.
If the CJ-WJ shuttle stays in place, how would they achieve 8 tph east
of
WJ?
--
Richard J.
(to e-mail me, swap uk and yon in address)

On Jul 1, 9:25 pm, "Richard J." wrote:
Where have you seen that suggestion? I thought that 8 tph on the North
London Line east of Willesden Junction was a key feature of TfL's
proposals in order to reduce overcrowding on the WJ-Stratford section.
If the CJ-WJ shuttle stays in place, how would they achieve 8 tph east
of WJ?

East of Camden Road is what they care about, not WJ. This can handily
be done by the proposed Queen's Park to Stratford service, or in a
pinch a Camden Road - Stratford shuttle, as already operates in the
peaks.

U

--
http://londonconnections.blogspot.com

On Jul 1, 6:58 pm, Paul Terry wrote:

Pathing on the ELLE should be easier, but it is likely that the line
will have to be shared with some sort of SLL service to Victoria, so
there is all sorts of potential for circle-line-like delays - breaking
the service at Clapham Junction should help mitigate that.


I would expect the SLL service from London Victoria to be replaced by
the ELL service to clapham junction. I think the Victoria - Denmark
Hill - Lewisham service does share tracks with this in one direction
through Denmark Hill, but it needn't.


I don't think that the Orbirail project will ever run a fully circular
service, because of the potential for serious delays (like the circle
line but infinitely worse). Nothing's decided, AFAIK, but clockwise
services from Clapham Junction may terminate at Stratford for the
Olympics, and at Barking thereafter, although it has also been suggested
that they may (as at present) go no further than Willesden Junction.
Anticlockwise may only go as far as Surrey Quays.
--
Paul Terry


I haven't seen anywhere the idea of running services from clapham
junction only as far as surrey quays - what'd be the point? Stopping
one station away from the most important interchange on the line
(Canada Water) would be really silly, and there aren't any extra
platforms at Surrey Quays. With the Clapham Junction branch, there
are planned to be 16 tph on the ELL, which it can surely cope with.

Mr Thant wrote:
On Jul 1, 9:25 pm, "Richard J." wrote:
Where have you seen that suggestion? I thought that 8 tph on the
North London Line east of Willesden Junction was a key feature of
TfL's proposals in order to reduce overcrowding on the
WJ-Stratford section. If the CJ-WJ shuttle stays in place, how
would they achieve 8 tph east of WJ?

East of Camden Road is what they care about, not WJ. This can
handily be done by the proposed Queen's Park to Stratford service,
or in a pinch a Camden Road - Stratford shuttle, as already
operates in the peaks.

The Queen's Park - Stratford service ia a post-2012 development that
requires extra stock on the Bakerloo Line, and assumes that the Clapham
J. - Willesden J. service will run via an electrified GOBLIN to Barking.
Your suggestion that all "they" care about is Camden Road - Stratford
doesn't fit well with the efforts they are making to create an orbital
rail service.
--
Richard J.
(to e-mail me, swap uk and yon in address)

Colin Rosenstiel wrote:
In article ,
(Tom Anderson) wrote:

There is another option - if trains didn't visit Clapham Junction
at all, they could go from Imperial Wharf to Wandsworth Road
directly, without reversing. I don't have a track map to hand, but
ISTR that this can be done without conflicting movements across
other tracks.

Misses out a rather important traffic objective, though.

Another option would be to maintain the status quo on the West London line
and to continue Orbirail on from Willesden Junction to South Acton, thence
via South Acton Junction and Kew Junctions to join the Brentford loop,
running through Barnes and Putney to Clapham Junction and on via Wandsworth
Road, creating a true orbital service. Gunnersbury to Richmond could then be
turned over entirely to District Line operation.