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5-15-1972 dredging adjacent to the Coffer Dam preparatory its removal. the story of the 1900 break wall is a book by itself. The final program includes sweeping the intake area with a huge bar 3' in diameter and up to 50' long, back and forth. When large stones are located, they are marked with a bouy and then they are removed by a crane. The area to the breakwall will then be be dredged to a depth of 30 to 32' and covered to a depth of 1 to 2' with coarse stone. the jetties are covered with armored stone 10 to 100 lbs. pumped into place by conveyors. The rip-rap stones, 20 to 4000 are put into place by scoes using drag line buckets. The in between size helps to keep small stones in. The 8 to 20 ton stones are properly placed figuring on certain amounts of voids. This dissapates the waves on the pell-mel wall. Riparian stones are placed and sounded by the drag-line bucks in four places. A 4,500 ton manitowoc crane on a sup scow is used employing a marine operation with a special skill to peace the stones where they are needed. - LPSC Box slide # 14-272 - slide numbers 14-273 and 14-275, also 2005.243.189 and 2005.243.190
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