Jack Taylor wrote:
Tom Anderson wrote:

Quail just calls it the 'City Line', and puts the junction at 5 miles
and 10 chains on the NLL, the platforms being at 5 miles 39 chains;
29 chains is 583 metres. I don't know where on the platforms the 5:39
point is, and there is a point before the junction where the down
City crosses the up NL. There's also a junction with what Quail calls
the 'New' line, the link from the DC lines to the NLL that Charles
calls the City Line, at 5:13. And, as Richard mentioned, not all of
that distance is wide enough for platforms anyway.

There's also the fact that the signalling is currently at the end of
the platform and would need to be moved nearer to the junction if the
platforms were extended that way, retaining the required overlap, for
safety reasons.

The up station starter would obviously need to be moved to the end of the
extended platform, but Kensal Green Junction is already protected by another
signal (HL 1106) nearer the junction.
--
Richard J.
(to email me, swap 'uk' and 'yon' in address)