Build a Road-over bridge

Impermanent Ways - volume 6... Noodle Books: 978-1-906419-99-8
Impermanent Ways – volume 6… Noodle Books: 978-1-906419-99-8
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 image is on the oblique and needs to be adjusted
The image is on the oblique and needs to be adjusted

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 adjusted the perspective then constructed an ellipse to match the arch
I adjusted the perspective then constructed an ellipse to match 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.

I reduced the image to b/w to use as a template
I reduced the image to b/w to use as a template

The northern exit starts its evolution
The northern exit starts its evolution

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.

A few details about Boltorr Road Halt

First draught
First draught
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.

Moorscaping…

Prospect along the tracks from Boltorr Road platform
Prospect along the tracks from Boltorr Road platform
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…

The Boltor Brook has become a mighty gorge
The Boltor Brook has become a mighty gorge

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.

From the dam overlook to Wynderidg trig point
From the dam overlook to Wynderidg trig point

Now the bulk of the terrain from the basin to the Boltorr road overbridge has to be set in.
Butelph's Cross (11C) and Wynderidg trig point loom above the tunnel
Butelph’s Cross (11C) and Wynderidg trig point loom above the tunnel

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.

The permanent way and the dam access track head northish toward the Boltor road
The permanent way and the dam access track head northish toward the Boltorr road

Life is great when I rule the world. First day of spring, soon.

Boltorr Road Halt - original track plan - evolution applies
Boltorr Road Halt – original track plan. Workin’ towards – evolution applies

Getting plastered…

Just skimmed a slip mix of plaster of Paris over the slopes of Bolt Tor. Quite easily the muckiest task yet. Plenty of drips on my hard worked stonework, but a minute with a soapy cotton-bud seems to get rid of most of it.

In the remaining section I might just skim exposed ground or rock. Static grass covers a multitude of sins.

However, the skim also seems to strengthen and harmonise the whole scene immensely. I’ll have to think about this.

Just thought, I need to plan the path – a favourite for ramblers and Sunday afternoon walks – from the dam towards the station and Boltorr Road (for The Warren Dartmoor Hotel). It needs to look walkable and yet be able to get the occasional Land Rover up it.

Oh! And some rocks and boulders for outcrops and rock faces… Will it never stop?