The Whitehorse Dam, 1958 By Al Lister

1. The Whitehorse Dam, 1958 By Al Lister I was employed by General Enterprises Ltd. inWhitehorse Yukon, working in a gravel pit where I learned to operate various equipment. I was sent to work with Poole Engineering who were building the Whitehorse dam. Using a small, ex-U.S. Army Loraine crane, I performed numerous light weight duties like lifting timbers, bundles of lumber, holding work platforms over the water, driving piles etc. While working with these professional trades people, I learned many dam and bridge building techniques and skills. Wish I had taken many more pictures, but being young, I didn’t appreciated the future historic value.

2. Summer, 1958: A cofferdam was being built for the fish ladder weir construction. Note the damaged cofferdam module at far left. This module had been placed at the far right, but the strong current had other ideas. Cranes and crew were removed from the structure while engineers evaluated the security of the cofferdam after it was shaken by this event.

3. Cribbing modules for the cofferdam were built on the shore.

4. A Poole Construction crane places the module, but even with the weight of old crawler tracks draped over it, the strong current soon swept it down to the other end of the cofferdam, even while the crane tried to restrain it. This caused the cofferdam to shake as it bumped along the way.

5. With the crane holding, and two cats on the shore struggling to position the module, the river still won the fight. The river bottom was solid, rough rock.

6. A ‘monkey’ attempts to salvage the pieces, but the effort was mostly unsuccessful. Residents of the Bering Sea get timber.

7. Bridge carpenters work tongue-and-groove planks into place to help make the cofferdam watertight. The small crane then gently bumps them down with a 1,000 pound free swinging drop hammer to conform to the shape of the solid rock riverbed you will see in later photos.

8. Large rocks were gently placed in the cofferdam modules before filling with smaller rocks and gravel.

9. Dewatering begins. The small crane with a clamshell then dropped hundreds of buckets of fine gravel and sand along the sheet piling to help seal the leaks.

10. A view of the project from the dam. The fish ladder and weir, to be built adjacent to the cofferdam, will allow the Chinook salmon to continue their 3,200 kilometre swim from the Bering Sea.

11. Another view from the dam before the tailrace was installed.

12. In October 1958 the Yukon River was turned off. This was to allow for the otherwise difficult construction of the fish ladder entrance and other work.

13. The ‘never-before-seen’ Yukon River bottom

14. More river bottom

16. The cofferdam for the “Longest Wooden Fish Ladder in the World”(366 meters) is built while the water is off. Today this fish ladder features a very popular public viewing area with underwater windows, video cams in strategic locations and monitors.

17. A dozer works in the middle of the river near the Riverdale bridge.

18. The view from the bridge near Whiskey Flats.

19. The wild Whitehorse Rapids are now tamed.

20. Earlier dam construction.

21. Interior of dam – spillways.

22. The Gatehouse – powerhouse intake structure.

24. Summer water flow with tailrace built. Fish ladder in background.

25. And one last view from the cofferdam. Note the pile driver, far left.