The ‘lift-off’ bridge was always intended as a way of disguising the baseboard joint and will never be a fixture on the layout. Accordingly its weight is of no accord, unlike any thing that is such a fixture.

Plasticard was always intended too, mainly because of its ease of welding, a feature which would allow using flat pieces to build up a girder-like structure. In fact, it’s not strictly ‘Plasticard’. Some few years back I took out a bath during a modernisation of our bathroom. The bath side sheet was plastic about 0.060” thick and much of it was a dead-flat area. MEK caused melting so the flat area was retained and stocked for future use as plasticard. I’ve published pictures of the layout with temporary structures in foam-board and the foam-board ‘road’ of this bridge was used as a template to cut the plastic. This was carefully trimmed to ensure a nice snug fit with the card ‘roads at the rear of the layout.

Strips of 0.020” plasticard were cut and stuck to the lower surface of the plastic ’road’, these representing the bottom flanges of the side sheets of the large girder section. These side sections were also part of the bath panel and were topped by more 0.020” as the top flange of the girder.

What I now had would have passed as a modern, rolled steel girder constructed bridge but such would not have been the case for this application. More likely construction would have been from cast sections riveted together.

I was not looking forward to the next bit, which would have been fabricating ‘T’ section, and mocking rivet heads some way or other. I was rescued from this rather demanding and boring process by finding in my plasticard storage drawer, a sheet of rivets! I wasn’t aware that I had it; indeed I was unaware that such embossing was available, but I viewed it in great good humour.

This picture was taken while still at the “wonder if this’ll work?” stage. I decided it looked good enough to carry on.

Remember that I was making this up as I went along; having decided that there would be flanging plates either side of the vertical sheets, all riveted together, I also decided that the top flange of each casting would also have a riveted flanging plate. The flanging plates were all cut from this rivet-embossed sheet of plasticard I had found.

Still in ‘suck-it-&-see’ mode, the bridge buttress was made to match the retaining wall and is resting in its intended position and the bridge too is in its intended position. Weight is not a problem here, so the buttress is made of 6mm MDF which is thick enough to accept No. 6 woodscrews to be used to fix bridge to buttress, but thin enough to not foul the loading gauge. However the lower wall-section does actually foul it by about a scale three inches!

The ‘undressed’ buttress on the near-side is of 10mm MDF because there’s more clearance there.

Since the pics were taken, the buttresses are screwed and glued to the bridge and I have a good, solid model that fits snugly in position on the layout but that will easily lift away to allow the baseboards to be folded to the ‘coffin’. No pictures yet but perhaps I’ll post some when the cobbles and paving slabs have been laid.

Now! Stop all this web browsing and get some modelling done!