Public works . were transferred full scale to the woodenplanks forming the lower edge of the forms whichwere cut to fit the irregularities of the rock bottom^care being taken to cut them first for the deepestwater, so that the successive positions of the formrequired only to have the planks trimmed a littlemore. HANDLING AND FORMS The gantry tower was set up on the deck of ascow, the form suspended from it and properly con-nected and adjusted and the towei- and form weigh-ing together about 110,000 pounds, lifted by a pairof steel rope bridles attached to the 8-part hoistingtackle o
Public works . were transferred full scale to the woodenplanks forming the lower edge of the forms whichwere cut to fit the irregularities of the rock bottom^care being taken to cut them first for the deepestwater, so that the successive positions of the formrequired only to have the planks trimmed a littlemore. HANDLING AND FORMS The gantry tower was set up on the deck of ascow, the form suspended from it and properly con-nected and adjusted and the towei- and form weigh-ing together about 110,000 pounds, lifted by a pairof steel rope bridles attached to the 8-part hoistingtackle of the 75-ton floating derrick, which removedit from the scow and lowered it to position, main-taining it there until it was accurately centered andaligned and bearing on the rock bottom was effectedby the adjustable vertical legs at the corners of thetower. Usually the assembling and placing of theform and gantry tower was accomplished by a gangof 20 men in 24 hours. As soon as the form was in place a diver de-. FLOATING CONCRETE PLANT WITH HOISTING TOWERCHUTING CONCRETE FOR SUBMERGED FORM PUBLIC WORKS Vol. 52, No. 13 scended in it and made a thorough examination oftlie rock bottom to insure the proper bearing at allpoints, fill any openings between the forms and therock, and make necessary adjustments in the screw-jacks in the tower bearings. The diver also oper-ated a hydraulic jet of 200 pounds pressure and1J4 inches nozzle diameter to loosen any earth orother material on the surface of the rock, which wasimmediately removed by the suction pipe of a 10-inch centrifugal pump. CONCRETING After the rock bottom had been inspected, satis-factorily cleaned and the form adjusted, the latterwas filled with 1 :5 concrete made with Niagarariver sand and gravel and having an extra bag ofcement per cubic yard of concrete for all the under-water construction. The concrete was mixed in a 1^-yard Lakewoodmachine installed on a scow that was moved up toposition as soon as the form was
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectmunicip, bookyear1896
