All types of winches and cranes must be provided with means to stop and hold the proof load in any position, and the efficiency of such means must be demonstrated. Electric winches, electrohydraulic winches fitted with electromagnetic or hydraulic brakes at the winch, or electric cranes, must be equipped so that a failure of the electric power must stop the motion and set the brakes without any action on the part of the operator. Current for operation of electric winches and cranes during the tests must be taken from the vessel's circuits. Shore current may be used if it passes through the vessel's main switchboard.