Friday, June 2, 2017

CP 1908 Trestle over Old Man River at Lethbridge, AB

(Satellite)
Bob Kline posted
Lethbridge, Alberta, circa 1908. "Erecting Lethbridge Viaduct over the Oldman River." 8x10 inch glass negative. So that's how they did it.....
Richard Koenig Never saw this before: a big template is used, begin at bottom and work up.
Jeff Bransky The big rectangular framework at the top is like a template or armature but it is also scaffolding for workers to stand on. Very impressive. I like seeing the men standing at ground level and on the concrete pads for a feeling of scale. It is also interesting to see the large moveable crane reaching way out to build the vertical support structure that is nearing completion.
Satellite
The curved black line you see in the overall satellite image referenced above is a shadow of the deck. If you zoom in, you can see the deck, piers, and trestle steel.  On the south side the trestle steel is clearly visible because it does not have the confusion caused by the shadows.
Jeff Bransky commented on the above posting
Jeff Bransky This photo reveals the finished viaduct where you can see the spacing of the framework modules easier. In addition, the B&W construction photo shows temporary bracing on the sides of the end structure which was later removed. If you look below the smaller steam crane in the construction shot, you can see men on scaffolds working. They may be painting the bridge. I'm assuming the rivets were previously installed in the area where they are working. To see more photos visit this site which also shows the river in flood stage:
http://dailyphotodose.com/tag/high-level-bridge/

[Note the man standing on the front pier in the first photo. The flood pictures show the water almost covering those piers. So the river level is up about 15-20 feet.]
Jeff Bransky commented on the above posting

Jeff Bransky commented on the above posting
Update: this is the featured bridge in A Brief History of High Railway Bridges.

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