"Building the upper cofferdam was really a problem child. They poured a concrete facing on it, to take care of the river's surge. It seems to me that my uncle worked all night for that cofferdam worked all day and all night. It's a slow job, building a cofferdam, because for each layer of 12 inches that you put down, you have to tap it with a sheep's foot. Have you ever seen on the highways this gadget that goes around and taps the soil? Well, they had that. They couldn't tap it when it was underwater, but after it got up a ways, then they'd start tapping it. "60 - Steve Chubbs "My first job high scaling was over the Nevada valve house, cutting down to put the valve house in. That was the steepest canyon wall of all. We had a crew of men, and they came and went together all the time. I'd have a buddy that worked with me, and we'd be together all the time... We tied our rope to a steel in the ground at the top of the canyon wall. We tied our safety belts and our bos'n chair on that. We had inch ropes... We had an extra rope to tie the jackhammer on, and we tied our steel on, too. "But that was a good job. I got paid $5 a day to start with. Afterwards I got $5.60. I believe that was one of the safest jobs they had... It wasn't any worse than anything else. One thing, you were sitting down all the time. It was a sitting-down job. "61 Joe Kine Earthen lower and upper cofferdams straddled Black Canyon, bracketing the dam site and preventing seepage into areas that would be primed for concrete. The upstream structure (above) was covered with concrete in order to resist the pressure of a swelling lake and the possibilities of flash floods as snows melted. A rock barrier protected the lower cofferdam. Most dramatic of all the workmen in Black Canyon were the high scalers who swung out from the cliffs on ropes secured to steel rods and then set about prying, cutting, or blasting away loose or uneven rock. Although some four hundred high scalers were employed at any one time, only seven lost their lives while removing the equivalent of 137,000 cubic yards of stone.