25 November 2008

Of fiddle yards and gradients

Finally, I have laid the first track bed. OK, so it's only 60cm long and doesn't go anywhere yet, but it's progress.

This is a close-up of the centre rear baseboard section, now complete with trackbed. The anatomy of this picture is as follows:
  • The plywood section at the front is exterior baseboard - this will be the front of the station and will probably have a road, or a bus stop, or something such. Maybe even a tram stop eventually.
  • The vertical plywood risers form the supports for the main board which will sit on top of them
  • The five track sections sit on an MDF trackbed which is the central section of the storage sidings which will be underneath the station board.

To have arrived at this configuration has required some redesign, a lot of rethinking, and an ounce of hope that it will all work. I had originally planned to have the storage sidings lower than this - below the main frame in fact - but the gradients required and the mass of existing woodwork in the way proved problems too difficult to overcome. So I have alighted on this configuration, which raises the station a few cm higher but makes the storage sidings easier to construct and keeps the entire system portable. Even so, there is not much clearance in the storage sidings and accessibility might be an issue (hence I'm not officially calling it a fiddle yard). At first I think I will have to make the station platforms detachable so I can get at the trains parked underneath. Eventually I could think about a slide-out section.

The layout design is still evolving but is beginning to settle into a stable pattern. Just as well, given that all of the next steps will involve cutting wood to the shape required by the track design. The total height range of the layout is about 14cm - the storage sidings have the lowest elevation and the branch line bridge over the mainline the highest. There are some places where the gradients are tight - notably the 14cm drop in about 3m, including a station, for the branch line from the bridge down to the storage sidings. One possible solution is to swap the bridge orientation so that the mainline runs over the branch line. I am still thinking about that.

Here is the same view as above but with the top board in place. The station board will be 3cm higher than this in the end to provide clearance for the storage sidings.

Next task: to finish putting this frame together and then repeat nine more times with different configurations. But first I think I'll lay out the entire storage sidings (sub-surface) track bed, so that I know where I can and can't put risers for the top board.

Needless to say, I've given up trying to estimate when it will all be finished.

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