a geared drum that provides mechanical advantage for applying tension to a line, sheet, or halyard. The drum is turned with a winch handle, or by a grinding pedestal, electric motor or hydraulic pump. A ratchet stops the drum from turning back under load. Some winches are equipped with a self-tailer, a clamping device that grips the tail and prevents it from accidentally loosening. Some winches offer varying ratios of mechanical advantage and rotational speed that are selected by reversing winch handle rotation, or by moving a switch or lever. Also referred to as a coffee grinder.