A frozen dam solved a big problem

On the east side of the Columbia River, several landslides had already occurred, burying equipment and threatening lives, slowing down the construction of Grand Coulee Dam. Reporters watched the 200,000-cubic-yard hillside for the next story, and in July 1936, the story broke that a solution had been found: the WMAK engineers planned on freezing the slide area.

They did it with a refrigeration plant, the largest ever used in construction at the time, which had the ability to make 80-100 tons of ice per day. By the end of August, six miles of 3-inch-diameter pipes had been sunk along the base of the water-soaked slide area. The pipes were filled with liquid and cooled by a huge refrigeration unit that sat above on a ledge. The area frozen was approximately 100 feet long, 25-40 feet deep and 25-50 feet thick.

By November, the excavation was finished, and concrete poured to the level of the frozen dam. With the job finished, the refrigeration unit was shut down and disassembled, allowing the ground to slip up against the footing of what would be the eighth wonder of the world, the Grand Coulee Dam.

— J. Kemble, Them Dam Writers

Image courtesy Coulee Pioneer Museum