This blog expands a little on the Swanlink scheme around Waterloo.
A key part of Swanlink's relatively low cost is using surface access as far as Waterloo. Here I show some pictures that aim to explore that area in more detail:
At the south-west end of Waterloo is Westminster Bridge Road. The road is directly under the station throat. Swanlink proposes to build a new bridge over the road, at least two tracks wide. This requires the demolition of some non-listed commercial properties and relocation of railway equipment.
Moving north-west along the south side of the station the Swanlink project would remove the taxi road completely, lowering this to ground level or slightly below. The Spur Road ramp from Baylis Road would be redeveloped to replace the facilities lost underneath the current taxi road (such as deliveries and Waterloo & City line access). The taxi road (which is about 5m above ground level) is shown here:
East of the station a row of non-listed commercial buildings would be taken:
This provides access to the Waterloo (Cornwall Road) bus garage which would be the tunnel portal site:
Finding a route from there to Blackfriars Road through Southwark station will not be easy, especially given some buildings which are likely to have piled foundations. A tight curve may be needed, but speeds can be relatively low just outside Waterloo. The proposed Bankside station would use this land on Blackfriars Road:
Overall, the route on the map has been chosen to avoid tall buildings, but without detailed sub-surface maps it is impossible to confirm the route. Finding a route for tunnelling in London is hard!