The Dominion Bridge Company was once an industrial juggernaut, a giant in the industry with factories all over the country. Not just a maker of bridges, although that was a huge part of their business, their output was all manner of fabricated, forged and cast metal components and machinery for industry and government. The company later crashed and burned and by the late 1990s was gone.
Even though they are no more, there is a legacy and examples of their work can be found everywhere. Included in that are a huge number of vintage bridges constructed by the company long ago, found along quiet, remote and often forgotten back roads and located all over the province.
The span seen here came from the Dominion Bridge Winnipeg Manitoba factory and is still adorned with that factory’s builder’s plate. These plates, by the way, are not always dated nor do they typically contain a serial number. It seems the Winnipeg plant concentrated on modest sized through-truss bridges much like this one. That’s all they seemed to make. Our bridge is hardly a unique structure and there are countless similar looking examples much like it, numbering in perhaps the hundreds, located at various rural road stream and river crossings all over Alberta. Many are painted the same blue-ish green colour.
While it’s not known when this bridge was built (records have a question mark) the style of construction and the general history of the road network in the area tell us it’s probably from the 1910s or 1920s. Most of these style bridges across the province date from around this time, a busy period when many rural roads were being built.
This span was built to a variation of the Pratt Truss design, known as a Parker or sometimes Parker Camelback Truss (technically there are some differences between a Parker and Parker Camelback but it’s not worth worrying about, IMO, that much). Like a true Pratt, the diagonals slant inwards, but the top chords have been modified with a gentle arch instead of being straight and parallel with the bottom chord. This makes the bridge somewhat lighter, without sacrificing strength, but does make it somewhat more complicated to construct and therefor a bit more costly. By the 1940s the Pratt design mostly fell out of favour and was replaced by various deck styles.
The Winnipeg Dominion Bridge plant operated from the early 1900s and into the 1990s. The peak of production seems to be the 1920s and again during World War Two. Although Calgary also had Dominion Bridge factory, which was much closer, their output was mostly machinery for the province’s oil and gas industries. For one they made pressure vessels – we’ve seen some of them at the old Turner Valley gas plant.
From the factory the bridge would have been shipped in pieces by rail to the nearest convenient siding. From there it’d be a road trip to the final location for reassembly.
This bridge does not see a great deal of traffic which means it’s likely to last a long time. This same reason is why most of these original structures remain in service today. The vast network of rural roads, in the Alberta Range and Township grid system are essential but most are not all that busy. As was typical, the structure is one lane wide. That’s how they built ’em (a cost saving measure). Yield to oncoming traffic! Also, there are load limit restrictions. Not unusual either. The deck is wood, which can be replaced as it wears.
Seen flowing below is Drywood Creek which was born in the mountains to the west and soon after passing under the bridge empties into the Waterton Reservoir. Some of the water course shows damage from recent flooding (probably the 2013 floods, which were of Biblical proportions). The bridge is a fair distance above the water, so it was likely little affected. Maybe some minor undercutting.
Dominion Bridge starting failing in the 1980s. Overcapacity was one problem. One by one the factories were scaled back, closed and eventually disposed of. By the late 1990s, the firm was gone.
Besides Winnipeg and Calgary, Dominion Bridge had factories in Lachine Quebec (the main plant) and we’ve heard also Montreal, plus Richmond and Burnaby BC, Edmonton Alberta, Regina and Saskatoon Saskatchewan, Toronto Ontario and Amherst Nova Scotia. They truly were a Canada-wide company.
This bridge is pretty run of the mill and nothing terribly noteworthy and is but one in a huge number out there. But it’s still in use after all these years and that’s quite an accomplishment. The boys at Dominion Bridge Winnipeg have done themselves proud.
If you wish more information on what you’ve seen here, by all means contact us!
Date: July, 2015.
Location: Range Road #290 near Twin Butte Alberta.
Article references: Dominion Bridge archives, Alberta Transportation.