I had hoped to find a laser-cut bridge kit somewhere on the interwebs, but nothing looked quite right.
My DAS chip method is tedious, but it looks so good. I think I’m committed to it now, if only to maintain a “look” across the layout.
I looked around Google images for a bridge to base Boltorr’s on, but didn’t find an example which fitted Dumnonia’s needs better than the one illustrated on the cover of “Impermanent Ways v6“. So I’m not certain the rights’ issues involved here, but buy the book! The whole series is a huge resource if you model in this area.
The real issue when building a model bridge which never actually existed, is getting the arch right.
The photo of the bridge on the cover is on the oblique, so I used an image editor to square the perspective and match an ellipse to the arch.
I then reduced the image to black & white to produce a template. I’ll jiggle with the width of the bridge and the chord of the road deck to fit my location.
In Boltorr’s case, this means spanning the branchline, a siding and possibly an extension of the platform under the bridge. I will also have to adjust to accommodate the road level above.
At this point, I’m not considering a hi-tech solution. It’ll be a combination of printer settings and a pair of scissors.
For construction I’m going back to 2mm MDF with appliqué stonework courtesy of DAS. This provides the most stable foundation.
Boltorr Dam and the rail bridge abutments were built using foam-board which tends to take a form of its own if it possibly can. This is not necessarily a bad thing, but for engineering elements it’s a problem. MDF resists the urge to distort far better.
The layout is based on a 8′ x 2′ module. I would have gone metric, but that would add an extra degree of complication. It’s an effort to even find a metric tape measure here in the US. Then there is the regular size of board material, usually 8′ x 4′.
The rail plane was designed to be a few inches above datum to enable depth as well as elevation to be rendered. I understand the attraction of a flat baseboard, but I’m really trying to represent the 3D nature of the landscape. I want it to look as if there were untold ages of geology and history before the railway scratched the surface of Dumnonia.
The original plan for Boltorr is rendered on the right. The drawing app is AnyRail and the track Peco Code75. I’ve since upgraded to Peco Bullhead which has only recently become available but only LH and RH points at the moment. A little bird told me that Peco may soon be producing a curved BH turnout, but if not the crossover will mean the track will have to be slightly realigned to accommodate straight points.
Other changes are fairly minimal and come about from the transition from 2D to 3D which exposes improbable or anomalous topography. The main issue has been that the vertical dimension has turned out to be more spectacular than I anticipated.
Just a progress report. Building your own world, even a tiny corner of it, is hard work!
It has always been a part of my brief to get as much elevation as I reasonably could and I have to say it’s working out.
Actually rather too well in that the Boltor Brook seems to have carved itself a fairly impressive gorge through the millennia so I’m having to rewrite the narrative a little. But there are gorges elsewhere on Dartmoor, so it’s not improbable. Besides it’s my universe, so…
Structural work on the dam’s basin is done and sealed for landscaping and water effects.
The iron rail bridge has been set in ready for track laying with a little final adjustment to the abutments to fix a couple of issues. It’s safely stored away while landscape effects go in.
Some plaster slip has escaped onto the masonry but this is easily brushed off for the most part and will be weathered, vegetised, etc when it all comes together, at some vague point in the future, or maybe in the past. You know what private universes are like.
Now the bulk of the terrain from the basin to the Boltorr road overbridge has to be set in.
I’ve plotted the track of the access road to the dam with a turning point and overlook for intrepid walkers. The path progresses northish towards the road with a shortcut for sightseers from the platform.
I really have to start detailed thinking about the road overbridge and construction. This element acts as a scenic break too and has to incorporate a bus stop and normal access to the platform. This was built way before any modern disabilities’ acts, so it’s likely to be just steps down.
Life is great when I rule the world. First day of spring, soon.
The dam complex is now hot-glue tacked in place, so the next stage is to blend it into the landscape and complete the permanent way from Boltorr tunnel to the Boltorr-Tavystock road bridge, then I can get on with laying the track.
The track levels should be in perfect alignment because I completed the track plane before sawing out the void over the Brook.
I had intended that the rail bridge be an open structure with gaps between the rails and the river below. However, this was going to be a modelling challenge, and besides, after thinking about it, I thought it unlikely that anyone, even Victorians, would allow a pristine water source to be contaminated by ash, cinders and grease dropping from a railway above. So, I’ve built a solid deck to contain the track and ballast.
The original bridge is a HO kit from The Micro Engineering Company – Single Track Thru Girder Bridge 75-520. Bollards are from Billing Boats and the railings are feed wires from various obsolete audio and USB cables super-glued into place.
The decking for the permanent way staff is made up from MicroMark Boat Decking and aged/weathered with Age-It-Easy. Yes. That’s what it’s called. Additional rivets are a MicroMark decal.
The rest is fabricated from styrene sheet and profiles from Evergreen and Plastruct, then “weathered” and further rendered with vallejo “rust” wash and varying degrees of acrylic washes from white to black from any craft store you care to mention.
Fortunately, there is a lot of leeway before you get the look right… But when it is, just fix with matt spray.
Next: blending the scenary or track-laying… Not sure what…