Transcript Slide 1

The Whitehorse Dam, 1958
By Al Lister
I was employed by General Enterprises Ltd. in
Whitehorse 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.
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.
Cribbing modules for the cofferdam were built on the shore.
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.
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.
A ‘monkey’ attempts to salvage the pieces, but the effort was mostly
unsuccessful. Residents of the Bering Sea get timber.
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.
Large rocks were gently placed in the cofferdam modules before filling
with smaller rocks and gravel.
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.
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.
Another view from the dam before the tailrace was installed.
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.
The ‘never-before-seen’ Yukon River bottom
More river bottom
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.
A dozer works in the middle of the river near the Riverdale bridge.
The view from the bridge near Whiskey Flats.
The wild Whitehorse Rapids are now tamed.
Earlier dam construction.
Interior of dam – spillways.
The Gatehouse – powerhouse intake structure.
Summer water flow with tailrace built. Fish ladder in background.
And one last view from the cofferdam. Note the pile driver, far left.