2. If you look on a map where Old Street is in relation to Farringdon, I'd say that would not be the easiest thing in the world. If you want it to go to a section level with the current Thameslink platforms, then you need to have a lot of tight curves along Old Street itself, and if you want to have a separate level then good luck negotiating the grade changes to get around Crossrail. Even then you'll need to have a fairly tight curve on a fairly steep grade to get your trains to face the right way (ie South-South-West) before you hit City Thameslink.
To fix this I would modify this proposal:
Instead I would still close the Old Street-Moorgate section of the Northern City Line, but build a new rail line from Old Street to City Thameslink (instead of Farringdon) to make it a less difficult curve than the original plan, this will also mean that there is a intimate station at Barbican
Due to this (and the fact there is a 20tph gap in the original plans), the London Bridge-Blackfriars-City Thameslink section will now become 6-tracked, the rest of the core section will remain 4-tracked since there would not be enough services to demand 2 additional tracks (the Northern City Line and West Anglican services will diverge at City Thameslink)
3. Lea Valley lines to Farringdon (from Bethnal Green), while you have more distance, you'll either end up with a MASSIVE curve, which will be very expensive, or more tight/steep workings.
To fix this I would modify this proposal:
Instead I would link the linking section from Bethnal Green to Barbican, where it will meet the Northern City Line linking section which joins up with the main Thameslink Core section at City Thameslink
I have absolutely no idea where the space would come from to 4-track the Thameslink core without demolishing a sizeable amount of Central London![/QUOTE]
Well for the sections (of the Core Section) that are underground (St Pancras Thameslink-Farringdon, Farringdon-City Thameslink), no buildings would have to be demolished, all you would have to do is bore additional tunnels and rebuild City Thameslink (which is underground)
As for the rest of Thameslink Core section, well I will explain by dividing it into sections:
(Note due to changes to my proposal, the London Bridge-Blackfriars-City Thameslink section will now become 6-tracked, while the rest will remain 4-tracked)
Blackfriars: The 2 terminating platforms would need to be rebuilt into though platforms, while another 2 though platforms would have to be built to the east of the current station, this will mean that Blackfriars can no longer be considered a rail terminus
Blackfriars-City Thameslink section: Due to the enlargement of Blackfriars Station to accommodate another 2 platforms, 2 Puddle Dock will have to be demolished, along with 160 Queen Victoria Street (BNY Mellon Centre), Playhouse Yard (and the buildings north of it) and 15 Blackfriars Lane
Farrringdon: 39-41 Farringdon Road will have to be demolished to allow the building of an additional 2 platforms at Farringdon
5. People who work in the city might assassinate you. I mean, you've just replaced a very convenient, 6 platform Terminus, with many, many destinations in SE London and Kent and a Tube Station with, well, just a Tube station. You'd need significant improvements on the southern part of the Circle Line to shift all those passengers.
Is Blackfriars close enough to Cannon Street to compensate, if it is then the area will gain services from a bigger range of destinations in London + SE and the potential capacity problems on the Circle/District Line (which is extending its trains from 6-car to 7-car) can be fixed by extending the trains from 7-car to 8-car
