Abstract: The upper block assembly of a crane is connected to the crane boom via a special universal joint having a pivot axis and a hollow shaft. The cable by which the lower block assembly is suspended is fed through the hollow shaft and extends to the crane winch via a pulley mounted on the boom. Guide pulleys are arranged on the upper block assembly and universal joint respectively so that the cable extending therebetween is coincident with the pivot axis of the hollow shaft. With this arrangement, the lower pulley block has unlimited freedom to swing laterally (side lead angle).

Abstract: A process for mooring a crane having a crane jib which is hingedly connected to a slewing frame, luffing wires for luffing the crane jib in and out, and a guy mast hingedly connected with the top of the frame, the luffing wires passing about hoisting blocks at the top of the frame. The process comprises positioning the crane jib in a fully luffed-in position, and connecting at least one guy wire between a fixed point at a distance from the crane and the free end of said guy mast. Some of the luffing hoisting blocks are then detached from the frame and are shifted toward the free end of the guy mast and are attached to that free end of the guy mast. The luffing wires are then tightened to swing the guy mast to a position to tension the guy wire by raising that end of the guy wire which is secured to the guy mast, after which the crane jib is luffed out.

Abstract: To permit an increase of the maximum permissible load of a crane for heavy loads, in particular an offshore crane, some of the luffing wires for luffing in and out the crane jib (4), are extended by guy wires (17); to avoid the disadvantage that the frame (3) of the crane with tie-back system can not slew, the part of the luffing wires connected with the guy wires, on the one hand, and the part of the luffing wires not connected with said guy wires, on the other, form part of separate hoists (6, 5) which can be operated by separated winches (14, 13).