Abstract: A mobile cofferdam for use in the construction of elongated structures win a body of water is characterized by a water-tight rectangular shell which is guided and supported off the previously constructed segment of the sill or wall structure being built. The mobile cofferdam shell is floated into place, sunk, dewatered, and used as a cofferdam during construction of the sill. The mobile cofferdam is guided and supported off the previous placed concrete sill or wall and proceeds in a horizontal slip-form fashion. The walls of the mobile cofferdam are designed as spaced truss structures with skin plate on the inner, outer, top and bottom surface thereof to define a chamber which can be filled or evacuated with water to float the shell structure. The trailing end of the shell conforms to the sill or wall under construction and includes seals along the contact area for mating with the previously constructed sill portion.

Abstract: A wicket gate for providing a dam in a navigable waterway is described. A cket gate is connected at one end to an axle which permits rotation of the wicket gate from a horizontal to a vertical position. The axle is supported on first and second carrier bearing, connected to a concrete sill within the navigable waterway. The wicket gate may be raised and lowered by a motor located within a gallery of the concrete sill. The motor is connected via a drive shaft to the axle of the wicket gate. This structure permits movement of the gate without props or other protrusions which could collect and hold debris.

Abstract: A movable dam gate hydraulically driven through a fixed strut to maintain regulate a pool of water upstream of a dam, the present gate structure is placed in series as a plurality of units to form a desired length of movable dam. The dam gates of the invention are operated from within a dry gallery which contains a single hydraulic cylinder and associated electric motor-drive hydraulic pump and oil reservoir for each gate. The dry gallery allows ready inspection and maintenance of the hydraulic equipment and prevents silting of the equipment such as occurs in prior art wet recesses within which hydraulic cylinders and associated apparatus have been previously operated. The present gate and gate system can be operated remotely, thereby providing greater safety and convenience to personnel.