Work continues on the Coquihalla. Over the weekend I mostly finished up a Central Valley truss bridge kit I’d had lying around for ages. This bridge kit was very close to the prototype bridge that existed at Mile 53.4, near the Kawkawa Lake Rd bridge to the south. That steel bridge replaced what was originally a wood truss. As originally constructed, there was a wood pile trestle at each end with the truss in the middle. After the steel truss replacement was in, the pile trestle on the east side was filled in.
From the aerial photo of the site attached, it is clear the flow of the Coquihalla could expand considerably in heavy flow conditions and these flows periodically took out the pile trestle at the west end. I also note via the attached satellite photo from Google Earth how significantly different the area and river bed is. This is important when constructing historical railways: rivers do change course over time, and/or riverbank is sometimes filled in or diked for development.
I say ‘mostly finished’ with this kit because there are some differences I need to remedy. The bridge is 20 feet longer than the prototype, but rather than cut it to pieces are and manage the tricky business of piecing it back together, I decided to fudge it a bit and go with 150 ft. I am modifying the x bracing at the top to more closely resemble the original. I also acquiring some more box girders as the type of braces supplied in the kit are not correct to my prototype. I’ve never built a pile trestle but I’m looking forward to trying.
To accomplish this scene I have used the historical aerial photo and printed it on a Designjet 450c large format printer. I then overlayed it on my foam base, placed my bridge as per that photo, and am using long nails to mark off where details like bridge footing and river banks should be. Next I will carve out the banks, river, hillsides etc. Then probably to pile trestle.. then water.
Apart from the kit, I created the bridge footings from notes and measurements I took of the original onsite (pictured). Tough to work with with all the plant life around it, but it was cool seeing that still extant footing, with the 1914 date stamp on it. Where it is now it is almost impossible to believe that trains once passed over it.