Barriers that manmade dams create result in declining populations of anadromous fish such as American shad, sea lamprey and Atlantic salmon. The fish are unable to breach the dam and return to the rivers of their birth, hampering spawning efforts.
Fish ladders have been successfully used at smaller dams, but larger dams must use a fishlift. The Hadley Falls fishlift consists of two elevators or "lifts" that carry migrating fish up and over the Holyoke dam, making it possible for the fish to swim up the Connecticut River, completing this annual migratory cycle.
Morris Material Handling worked closely with its Pittsfield Maine Partner, Somatex Material Handling, along with Kleinschmidt (energy and water resource consultants) and Cianbro Corp. to engineer this upgrade. Two 20-ton base mounted CJ hoist units, two 1-ton and two 1.5-ton Hevi-Lift M-Series hoists will become part of this elevator system.
Lift operators attract fish into the system by providing a current that most migratory fish instinctively seek out. They sense the flow and follow it into the lift system until they pass through a gate and enter the crowder area. At preset intervals, the gate closes horizontally forcing the fish into a small area above the hopper. The Hevi-Lift M-Series hoists operate the discharge gates that prevent additional fish from entering the elevator as the hopper ascends. The 20-ton CJ hoist unit raises the hopper, loaded with fish, to the upper level of the dam where the fish are released into an exit flume.
Morris Material Handling, www.morriscranes.com, 800-558-3886.