On Feb 3, 12:15*pm, Jamie Thompson wrote:
1924 new island platform added between the local station and the Hotel Curve
platform, numbered 14 and 15.

Quite how they manage with only 3 + borrowing some from the maid shed
these days is amazing.

Don't forget the extra x2 at Moorgate GN.

Opening up the Gas Works tunnels is not an option, as the Grand Union Canal
goes over the top of them. It might, I suppose, be possible to reinstate the
third tunnel, use the western one only for the suburban station (including
possible longer and/or additional platforms), the middle one for platforms
5-8, and the eastern one for platforms 1-4 and 0/W/Y or whatever it will be
called.

You could stick the canal into an aqueduct...it bridges obstacles
elsewhere with ease. Bridging the gap for the road is also (relatively
speaking, of course) trivial.

Boat lift!

I do have my doubts. Capacity is the sort of thing that gets eaten up
very quickly. I think the diversion onto Thameslink is going to be a
monumental balls up. The tube suffers with some delays with multiple
branches only going out to zone 5. Thameslink is going to have route
pollution from MML (from TL diagrams that use the fast lines), damn
near *all* ECML services thanks to the Welwyn viaduct, not to mention
the Peterborough services and the magic 3-track section, and they want
to merge 24tph into the 2 platform St. Pancras Thameslink....it's all
going to go horribly wrong, I suspect.

Not making SPTL 4- (or at least 3-)platform was an error. However, the
Central line works well, despite its multiple and far-out (including
Epping, which would probably be zone 7 or 8 if Essex CC hadn't lobbied
and paid to put it in Zone 6 before zones 7-9 were invented) branches,
on 24tph. ATO combined with clever signalling that reacts dynamically
to any delays in incoming trains is the key here.

--
John Band
john at johnband dot org
www.johnband.org