The earliest North American mechanism used to open miter gates on steamboat locks was muscle-powered, geared winches called windlasses or crabs, which quickly replaced balance beams when lock widths exceeded about 25 feet. This 3,360-pound windlass survived and is one of four known to exist in North America, apart from three sets of similar design on the Lowell Canal in Massachusetts. Eight windlasses were required at each lock. One winch opened a gate while a corresponding one on the opposite lock wall closed the gate, both taking in and letting out at the same time. These windlasses were used on the Muskingum River Locks from 1840 to the early 1880's.