Trainshed strenth.

[yorksrob]

This is a query for the infrastructure experts concerning the proposed Thameslink works at London Bridge.

I was having a discussion with a friend, who is not an engineer, but who is quite knowledgeable in the field of physics regarding the said works and was wondering if somebody from here could settle it.

The current plans are to demolish the existing trainshed (which I am quite fond of) and reconfigure the station with nine through platforms and six terminus platforms. I suggested that it would be physically quite possible to keep the trainshed but insert an additional island platform between it and the existing through platforms to give eight through platforms. (there currently looks to be room, although the east end would need to be fairly narrow, but no more so than the existing through platforms.)

My friend said that this might undermine the Northern wall of the trainshed making it dangerous, therefore if we want to insert an extra island platform, the shed will definately have to come down. Is this the case, or is there a technical fix to keep the trainshed?

Your opinions would be much appreciated

 

[bluenoxid]

Is it possible to keep it? Yeah course. Is it feasible? well, without access to the drawings and tests of the buildings, I can't give you a professional opinion.

It's all possible but feasibility does come into it and with the tight space and major works required to do it, the sheer expense is likely to make the plan difficult. It's all well and good saving a little bit of heritage but when you start talking about figures which could provide 100 nurses instead, then the plan becomes unfeasible.

 

[yorksrob]

Thanks bluenoxid,

Yes, I suspect it would simplify things to sweep away the lot and start again. And of course, they need nine through platforms and the extra three simply wouldn't fit in the gap
Nice to think that it would be technically possible though, particularly when so many have been swept away in London and replaced with subterranean car parks!

Incidentally, I read an article in the Times about The Shard about four days ago which included a lovely artists impression of the new skyscraper very clearly showing the trainshed tacked on the back, so who knows! I would have posted a link to the article on the Times' website but unfortunately they've left the artists impression off.

 

[Broken Viking]

Wouldn't it be both quicker and cheaper for them to build the new platforms on a flyover above the existing through lines?
If four such platforms were built "hard-wired" to the Charing Cross branch, it'd split the Waterloo/Trafalgar services onto their own platforms, freeing up capacity "downstairs" for extra capacity towards Blackfriars.

That, and a left-hand spur could probabally be built from the "upstairs" to allow trains to be routed into LDB and then onto the down line leading away from Blackfriars - Allowing through services to run Dover/Ashford -> London -> Brighton if ever needed, too! 8)

 

[yorksrob]

Wouldn't it be both quicker and cheaper for them to build the new platforms on a flyover above the existing through lines?
If four such platforms were built "hard-wired" to the Charing Cross branch, it'd split the Waterloo/Trafalgar services onto their own platforms, freeing up capacity "downstairs" for extra capacity towards Blackfriars.

That, and a left-hand spur could probabally be built from the "upstairs" to allow trains to be routed into LDB and then onto the down line leading away from Blackfriars - Allowing through services to run Dover/Ashford -> London -> Brighton if ever needed, too! 8)

Hi Death, I've often wondered whether a two level solution might in the end be easier for London Bridge If you continued the viaduct from the upper level of platforms on a second deck over the viaduct on the Charing Cross side of the triangle through Borough Market and continued it to join the Blackfriars line in the Metropolitan Junction area, not only would you provide extra through capacity at London Bridge, but you would also eliminate the bottle neck at Borough Market without taking extra land, and provide a fly over to carry Thameslink trains over Charing Cross trains.

This might be expensive - but how expensive will it be to solve these three problems seperately in the traditional manner?