Abstract: A crane having a fixed mast and a boom pivotally mounted at the top of the mast for movement in a horizontal plane through at least 180.degree. and in a vertical plane downwardly from the horizontal plane at any position of the boom relative to the vertical axis of the mast, a load carrying trolley movable along the length of the boom, hydraulic means located at the top of the mast controlling the movement of the boom in the horizontal plane and hydraulic means between the boom and the mast controlling movement of the boom in the vertical plane.

Abstract: A boom lifting system for a crane of the type having an upright mast and a boom hinged to the mast. The system has a brace extending between the mast and the boom. The brace is pivotally connected to both the mast and the boom and has a hinge dividing it into a short section, connected to the boom, and a long section, connected to the mast. A hydraulic cylinder is pivotally connected to both the boom and the short brace section. Actuation of the cylinder straightens or bends the brace to respectively lift or lower the boom relative to the mast.

Abstract: A travelling gantry crane is mounted for movement along rails laid on the weather deck of a ship, but is adaptable for shore installations. Preferably two similar cranes are used in face-to-face arrangement and operable together as a unit for maximum lifting capacity, but they can be operated individually. Each travelling gantry crane has a pair of C-shaped leg members supporting between them a bridge girder, the leg members being movable by driven wheels. A shuttle girder is mounted for movement along the outward facing side of the bridge girder to provide for maximum outreach beyond the ends of the bridge girder. A load carrying trolley moves along the outward facing side of the shuttle girder remote from the bridge girder. The invention includes various detailed arrangements for moving the shuttle girder and the trolley, for securing the gantry crane on the rails, etc.