Abstract: A retractable leg structure for undecking a crane's upper from its carrier including a box member having a circular cross section and a longitudinal axis affixed to the upper, a beam retained within the box and rotatable about the longitudinal axis relative thereto, and an L-shaped leg, including a tubular member having a free end hinged to the beam, the leg being manually swingable about the hinged connection between a stowed position in which the tubular member is oriented horizontal and inboard of the upper and a deployed position in which the tubular member is horizontal and outboard of the upper. There is a lock pin device for selectively securing the leg in one of the deployed and stowed positions, and an extendable jack secured to the fee end of the tubular member along with a crank arm attached to the beam. A hydraulic ram connected to the crank arm moves the leg between the deployed position and an operative position wherein the tubular member is oriented vertically adjacent to the ground.