Richard Wilson and I spent a productive day trying out the alignment of the York Road plan against the relevant baseboard and station building. This has been almost completely re-made internally towards the back to ensure that the lift shafts and lobbies are in exactly the correct position to line up with the plan at platform level.
The platform line to Finsbury Park will be hidden under the layout, but the up line and crossover to the north of the station will be fully visible. The plan may not be 100% accurate in that area, but we now have the full prototype plan showing tunnel sizes etc, so that it can be made correctly. It is almost certain that the station building will be removable, as there will be more of the underground structures modelled - the gents loo will therefore be made - it is no wider than the line of the platform track. The ‘area’ in the far left corner won’t be represented. The television screen will probably be covered over, when the underground section is on display.
Richard has mocked up the tube tunnel rings as a 3D print, which will save a vast amount of work and be very robust. The distance between rings is currently 30” - it should be 18-23”, but that will be modified in production. The different diameters for the crossing tunnel civil engineering can also be made as required.
The tunnel bore is generous on size, but that will be important for dynamic tolerances and it could also allow an N gauge tube train to pass, should one ever be manufactured.
The train in the image is sitting on a piece of fully sleepered track, but the production track will be more nearly flush ballasted and the cement infill in the lower part of the rings will also be included in the 3D print. I think it is fair to say that without the availability of CAD and modern manufacturing techniques, this line would be very much harder to make! It is also quite gratifying to bring all the modern techniques to bear on a 35 year old layout.
Tim