Truss bridge works

River bridge23OMWB

Work on my N scale Montana Rail Link layout has taken a back seat to Dudley Heath and Wheal Annah in recent times. This summer saw a resurgence in activity as I reconsidered the layout plan and track layout. The experimental building of a removable door bridge over the layout room’s entrance door changed my perspective of how the layout could work. Furthermore, operations revealed some shortcomings too – it’s a good idea to really operate a layout before starting any scenery! A new track schematic was devised together with some layout planning to relocate certain layout design elements.

I use an MRL profile book for my track planning, copying real life track layouts where possible to fit in a square layout room. However, working out a high level schematic takes a little doing at times. The idea is to work out how trains will be routed around the layout, incorporating staging yards and features such as a helix so trains flow over the layout as the real railways intended. Details such as the track layouts at certain locations can be determined after the basic route has been planned.

Planning the revised route for my MRL 4th Sub (water level route) meant I could eliminate one staging yard which was awkward to locate, saving a great deal of track at the same time. I am not a great fan of extensive off-stage storage and both of the yards at both ends of the line will act as scenic staging. After all, this layout will not host massive operating sessions, so having vast numbers of trains waiting off-stage to traverse the layout will not be necessary. As the plan developed, I realised that one of the blocks to further development of the layout was not just the determination not to cross the door way to the room, but the location of the helix too. It had to be moved – no small undertaking.

Removal to a position at the complete opposite corner of the room entailed the removal of a great deal of track and some bench work. Once disconnected, it rolled across the layout room floor without difficulty. Anyone who has undertaken such a huge revision to a layout will know that once track lifting starts, there’s always a little more to take up and so it goes. In the end, the only remaining track and wiring to survive the redesign was the formation at Missoula West and the west end of the reception roads. The yard reception roads were lifted and the turn back loop at the east end of the run taken out to accommodate the helix and the revised track formations. It is now all back in place and hopefully better designed.

The upper deck of the layout was also revised with a new, longer, double-ended staging yard replacing the two originals. It feeds directly into the helix at one end and allows trains to be staged for either end of the run. The upper deck of the layout is now a continuous loop whilst the bottom deck via Missoula West is a large return loop around the room. The secondary 10th Sub line fits better too and is now correctly pushed into its secondary role in the redesign as originally intended.

The new scheme has a longer main line run for less track and much less complexity. In common with the real MRL 4th sub, I wanted the track formations to be straightforward as possible. I can also install a reasonable representation of the small yard at Paradise MT together with the Clark Fork River crossing. And that is the current hold up to getting trains running once again. Until that four-span truss bridge is installed, trains are not going anywhere!

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To speed the job up a little, I decided to carve up four Kato Unitrack truss bridge spans so they would be reasonable, low cost stand-in structures for the real bridge. To fit, they would have to be skewed.

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This involved cutting off one side and fititng it one support along, with suitable modifications.

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I have to confess, that by this stage, I was not sure if this was such a good idea over kit bashing some Central Valley truss bridge kits.

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More detail remains to be added to each truss bridge span to further disguise its Kato origins. Once painted dull black and weathered, and fitted with some code 55 track, they will look great on the layout.

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The last picture of this blog entry shows the spline track bed (recovered and reused from the rebuilding of this section of the layout – in fact virtually all recovered materials were reused) leading towards the bridge location itself. The helix once occupied this site…amazingly. The Tortoise point motor just visible in the top right hand corner belongs to my Folkestone East layout which occupies the third deck of the layout room. Despite the chaos of partially rebuilding bench work and sorting out track and wiring, the changes are bringing numerous additional benefits to the project. Some scenes fit better and some hitherto ‘givens’ being relaxed has made the layout more enjoyable to work on. Sometimes, too much rigidity in layout planning can turn into an iron shirt which constrains the project and ultimately stifles progress.

Tomorrow – all being well with the weather, I am back out on the Monadhliath mountains!

 

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