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.

10 November 2008

Ready to add height

It's been a while since my last post, but finally I can report that all ten of the baseboard frames are completed.

It has been a slow process because of existing commitments and the usual constraints, but I am glad to have arrived at this point. From now on I will be doing work that reflects the final shape of the model, rather than foundation work. So the next task will be to make and attach the risers on which the final baseboards will rest. I'll start at the back (the station) and work round the sides.

The baseboard frames are all detachable, and fix to the primary frame using bolts. Small lengths of batten on the primary frame act as guides to ensure that the baseboard frames sit where they should. For the time being I expect to exploit the ability to remove the baseboards from the primary frame, for example by doing some work in our garage rather than in the loft itself.

I've made a few tweaks to the layout design, particularly simplifying the sidings. This should help to making sure that the entire board is not swamped with track, thereby leaving space for scenery.

Somewhat worryingly, I have discovered a leak in the roof up by the chimney breast. When I went up to the loft on Saturday morning so start work, I found a puddle of water on top of some damp plywood sheets. I guess I should be grateful that the plywood was where it was, otherwise the effect could have been a lot worse. The leak is under control for now but it might require attention, and there's no doubt that that would hold up progress.