A swivel for use in a crane has a stationary upper member which is secured to the boom and a lower member which is rotatable relative to the upper member and is connected with the end of the cable. The cable is looped beneath the swivel and the bight of its loop carries a roll which supports the load. A driving unit is provided to positively rotate the lower member of the swivel when the cable portions flanking the roll beneath the swivel tend to cross each other. The driving unit is of the self-locking type or the lower member of the swivel can be braked to prevent a change in its angular position independently of the driving unit. If such independent change of angular position of the lower member is desired, the machine employs a load-responsive clutch which disengages the lower member from the driving unit in the absence of load upon the roll.