"D7666" wrote in message
...
On Dec 19, 5:01 pm, Mr Thant
wrote:

This is relevant because every train to Moorgate is one less to/
through London Bridge (unless you can find somewhere new to start them
from), undermining the purpose of the scheme.

Holborn Viaduct ;o)

City TL out of St.Pauls sdgs.

For each train turned back in St Pauls Sidings you lose two paths to
Farringdon, one as it goes into the sidings and one as it comes out. To
avoid this you'd have to remodel the sidings so that they are between the up
and down lines. Even then you'd lose capacity when trains don't turn up at
the right time. I doubt that you could lengthen the platforms at Moorgate
for 12-car trains - down trains didn't call at Barbican because the platform
was too short. As others have pointed out, you couldn't operate Farringdon
at 24 tph with SDO. If you retain the Moorgate branch you can't lengthen the
Farringdon platforms south of the station, because that's where the junction
is. You can't extend them to the north because of the gradient of the
diveunder under the LUL lines. So you'd have to rebuild the gridiron so that
the Thameslink line stays level and the LUL line dives underneath it. All in
all completely unaffordable, and quite unnecessary, as passengers can change
at Farringdon to LUL (or in future, Crossrail) to reach Moogate or Liverpool
Street. Or walk.

Peter