London Banter - View Single Post

Tom Anderson · April 6th 09, 01:25 PM posted to uk.transport.london

On Wed, 1 Apr 2009, wrote:

On Tue, 31 Mar 2009 23:07:02 +0100
"Jack Taylor" wrote:
That's why they were proposing Finsbury Park as a terminus for some ELLX
services at one time.

A missed opportunity if ever there was one. It could have provided a
cross platform link for FCC & ECML passengers to docklands and the south
london lines and vice verca.

I didn't think you could achieve cross-platform interchange with both
Moorgate and KX trains. I've just got round to digging out my copy of
Quail to find out, but am little the wiser.

If you ran Canonbury trains into Finsbury Park, i think you'd have to
bring back the closed outermost platforms to do it, with the Canonbury
trains using the outer edges (which would presumably be numbered 0 on the
up and 7 on the down, or possibly 0 and -1 and 7 and 8, given that each
has two faces). That would give you cross-platform interchange with trains
calling at platforms 1 and 6, which means Moorgate trains and trains going
into, but not out of, KX on the slows. Not ECML trains.

In access terms, you could also run Canonbury trains into platforms 1 and
6 themselves, giving cross-platform interchange with 2 and 5, which serve
the up fast and down slow, and so ECML trains into KX, but again not out
of it. However, you'd only need to add one crossover between the Canonbury
and Moorgate lines south of the station to let Canonbury trains reach the
track between platforms 4 and 5, from where there would be cross-platform
interchange to platform 3, which is the down fast, where there are ECML
trains coming out of KX.

However, this is where it gets a bit messy. There's no way to reverse from
any down track to its corresponding up track at FP, apart from the fasts,
so you'd have to reverse out of whichever platform you used (resignalling
the Up Canonbury to bidirectional in the process, and presumably calling
it the Down & Up Canonbury to avoid confusion). That's not compatible with
running a high-frequency service on those tracks, which are also needed by
the Moorgate trains, so if this was done at all, it could only be
off-peak.

Furthermore, whether you use 0/7 or 1/6 (or 1/4), a given train will only
call at one of the pair, so it will either be able to deliver passengers
to down trains, or receive them from up trains, but not both. I'd hope
that the platform used would be selected to match the tidal flow, with 0
in the morning peaks and 7 in the evening, but you never know, and god
knows what you'd do in the middle of the day - alternate?

Anyway, as others have mentioned, all this involves crossing three tracks
on the flat on the way to FP, and two on the way back. Plus, something
that hasn't been mentioned, i think, is that the Canonbury curve is
single-track - the tunnel there isn't high enough to take two full-height
freight trains, so it was converted from two tracks to one in the middle
(where the arch is highest) when it became an important freight link.

tom

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