A crank arrangement (100) for operating a winch having an elongate crank arm (10), a hollow driving head (29) having an external engagement profile, a handle part (40) and a locking plate (25) arranged at an outer end of an actuator element rotatably taken up within the hollow driving head (29). Hinged lever arms (11A, 11B) extend in parallel on external opposite side walls of the crank arm (10) having protruding pins (18A, 18B) for, when at least one hinged lever arm (11A, 11B) is gripped, actuating upon the actuator element rotationally connected to the locking plate (25) such that the locking plate (25) will perform a rotational movement to assume a first position in which the locking plate (25) is aligned with the engagement profile of the driving head (29). When at least one the hinged lever arms (11A, 11B) is released, the locking plate (25) will be rotated to assume a second, locking, position in which it is misaligned with the engagement profile (30) of the driving head (29) limiting the rotational movement of the actuator element being provided. The locking plate (25) can be rotated to assume the first position via a one-hand grip.