For my modern diorama of Canyon Road, the centrepiece is going to be the scratch built wooden farm crossing that still exists over the CPR Galt Subdivision. I looked at various commercial bridges that are out there, and decided that nothing I could find made me happy, but I did find one that would work as a bit of a design guide/aid that I could buy cheaply. There is a Rix Products wooden bridge kit, its an older kit that’s been out there for a while, and is only single track. That said, it gave me something to look at for wooden bridge design, and to use to help me make templates for my own bridge built from stripwood. I pre-stained my strip wood for this project, using a couple of different Hunterline Stains and a isopropyl alcohol/India ink mix. This got me a variety of wood colours, and those colours into the wood before gluing anything together, that means there aren’t areas that won’t stain because the wood has been impregnated with glue. This is something I’m sure I’ve seen written about, but I learned the hard way building wood kits or scratch-building that you need to stain before you glue!
Pre-stained strip wood, home made jigs for a bridge and scratch building the bridge decks and trestle bents with them.
As you can see in the pictures above, i built two jigs using scrap styrene sheet and styrene angles. I used the Rix Bridge as a rough guide for beam and bent spacing, but also made tweaks to get the bents in particular to look like my photos of the actual bridge. The deck jig was set up to let me build up to a 40′ long deck (could probably do longer the way it is set up, but my base only let me add dimensions that far. The deck of my bridge is about 32′ across to clear the two tracks. The bents (legs) on either side are really close to the tracks and edge of the loading gauge in real life, and I wanted to replicate that in the model. Even with the jigs, before I built anything, I used some scrap cardboard to build a mock-up to look at spacing and dimensions. I hang onto a fair bit of scrap cardboard for painting and mockups, its a good practice to have some as it is a cheap and easy way to see if what you see in your mind translates well into 3D before you start actually building with more expensive materials.
Building Bridge Version 1.0. Working through the design and visualization, then building. But yeah, those ramps are a bit steep.
So, with the prep work done, and the diorama reaching a stage where the landforms to support the bridge were in place, I got going with the bridge. Slowly but surely, building sub components, the deck, the ramps, the bents, and getting them together and continually going back and forth from the workbench to the diorama to check fit and appearance. As I was working, the angle of the ramps started to gnaw at me, but I was so happy with the overall look of the bridge, I busily went about convincing myself that it was OK. It wasn’t until the bridge was “finished” and I shared a picture with some friends, one of who’s first response was “gorgeous but those ramps look really steep” did I finally go yeah, I’ve been trying to convince myself its OK and I’ll be happy, but the more I looked at them after that, the more I knew I would not be happy. The good thing is, as I have been moving slowly so I had not gone so far in the ground cover that it would mean undoing work to raise the hillside at the back and reduce the angle of the ramps. The ramp on the front side is shot and doesn’t land, so it would just be a take apart and adjust angle to match the change on the other side.
Rebuilding the ramps and raising the hillside to provide a more gentle ramp onto the bridge. Using a level that mounts into a camera hot shoe to check the bridge levelling.
Once I had confirmed that the ramps had to go, I started looking at how to best fix them. First looking at just making the side that reaches the ground on the back longer, but the more I looked at that, the clearer it became that what needed to happen was raising the hillside a bit so the ramp could stay around the right length while getting a gentler slope. To do this, out came the hot wire tool to carve off a piece of foam, and carve it to a shape where it could be glued on top of the existing hill, and blended in with the Woodland Scenics plaster cloth as I did for the rest of the scenery. With the hill increased in height, it was pretty straightforward then to get the angles cut on the ramp underframe beams and get it into place. All the different pieces then where re-assembled/adjusted and the bridge rebuilt.
With the bridge now approaching “done” in terms of the basic form, I was able to build the jacking that was installed beneath the bents at some point to raise the bridge to clear taller modern equipment, as opposed to building a whole new bridge for the farmer. These where built using HO Scale pre-cut wood ties, stained, and glued together. These actually are really handy for me, as they let me ballast the track without the bridge in place, as the bents sit on top of the risers, so my bridge can stay removable for a while still while I do scenery around it before eventually gluing it into place when I am done doing things that are easier without it there.
Finishing off the rebuilt bridge, getting the footings in (at some point the bridge was jacked up on site and raised to clear modern higher height equipment with large timbers under the legs, and ballasting the tracks.
At the end of the day, scratch-building made it really easy for me to take apart and re-do the things that didn’t work. I have some added details I want to add to the bridge, in terms of bolt castings for where boards meet to add a bit of detail, but, given the pre-staining of the wood I did, I am already really happy with it having the weathered appearance I want. Next up, getting started on the ground cover on the hillsides and telegraph poles.