As good a place to ask as any I guess... anyone got any plans of the future Thameslink underpass south of London Bridge, utilising the abandoned Bricklayers Arms route under the viaduct?
Particularly interested in proposed track layout.
I've been following this subject for a few years now and I don't think there has ever been any detailed engineering drawings in the public domain, even though there were drawings online for London Bridge, Blackfriars and Farringdon station alterations at a relatively early stage.
Modern Railways have published what you would call functional layout diagrams, but there's no construction details of viaducts or anything like that ever been made available, possibly because it would come under permitted development rights so wasn't part of the TWA Order process?
One of the last articles in the London Connections blog also had a useful comparison of the before and after layouts, in a similar level of detail to Modern Railways, but not a track plan:
http://londonconnections.blogspot.com/2008/07/thameslink-programme-illustrated.html