I went and dug a sheet and a bit of 10mm foam card out of the garage last night, so I could mark up and cut out the main bits of the Höllentalbahn board.

I added 5cm in each direction to the width and height of the plan in the previous entry - I may regret this, but it seemed like it wouldn't make that much difference to getting it though doorways, and it relaxes some tight areas on the plan. That gives a board size of 1900x500mm, or 6'2" by a bit over 19".

Cutting the thick board is interesting - to get good joints, you really need to get the cut perpendicular to the surface, which means you either need super-steady hands or some kind of specialist tool. The cutter I have has a small foot which keeps it at right angles to the surface. The problem is the blades are over-priced and don't seem to be as sharp as general purpose craft or modelling knives.

To get around this I make a guide cut just through the paper surface with a new blade in a modelling knife, then set the foam knife to ~9mm depth and cut through the foam. Finally finish with the modelling knife again to go through the last bit of foam and the other paper layer.

This seems to work pretty well and I only had wobbly edges on the really long cuts - a bit a shaving or sanding the bumps improves these.

One thing which worried me was that the top surface and long rails have to be made out of two pieces of board - the largest size I can get easily is ~1500mm long. I butt-jointed them and used masking tape to hold the joint while the glue went off. I've placed one of the reinforcing ribs under the joint in the top to give it a bit more support.

With all that done I glued and taped everything together, and let it harden under miscellaneous books:

So far so good. And just to show that modelling is not incompatible with other uses of the kitchen table:

(The small glass of port is strictly medicinal... )

Diagonal bracing is waiting on some more foam - all the bits I had left over were a couple of inches short.

I suspect I'll laminate a sheet of Styrofoam to the top as I did with Tanis, since the datum level for the track is rather higher than the lowest point on the scenery. That should make things much more rigid (maybe even obviate the need for diagonal bracing?) and also reinforce the joint in the top.

Nice to have made a start, albeit a simple one!