On Oct 29, 9:51*am, Jamie Thompson wrote:
On 29 Oct, 15:22, E27002 wrote:


Rather than build a new tunnel from Kings Cross to Bermondsy, would it
not be easier to extend the GN Electric tunnel from Moorgate?

It might seem so, but things to consider:
a) It's size cannot handle OHLE, which any new infrastructure should
be built to support (one day the southern network will be brought into
line )
b) It has metro station-spacing, unsuitable for a service serving an
area as wide as Thameslink (Cambridge to Essex Road, anyone?).
c) Said station are too short, and would be expensive to extend.
d) Closing said stations to remedy b&c would be unpopular with
existing users.
...and finally, e) Extending the tunnel from Moorgate means cutting
through both the planned Crossrail station's escalators, as well as
the Northern line tunnels.

Ergo, I think a new Crossrail-gauge tunnel from either Finsbury or
Ally Pally would be best, with stations at Finsbury Park, Moorgate-
Bank, Cannon Street-London Bridge, and Surrey Canal Junction. However,
either tunnel option would miss out on interchanging with KXSP,
forcing an interchange at Liverpool St. and a trip back along the
Circle.

My preference for the NC tunnels would still have to deal with e), but
covering the other considerations, would be to link it to the W&C, and
from Finsbury up to Highgate, then along back to Ally Pally, before
taking over the majority of the Hertford loop. Plans for the other end
of the W&C take it down to Clapham and off elsewhere...but that's
another thing entirely.-

IIRC because of the way it is configured, extending the W&C from
Waterloo would be very difficult. There was once talk of adding a W&C
station at Blackfriars. That idea may have merrit. But there would
be little return for the very high investement.