A marine knuckle boom crane includes a pedestal and a crane housing rotational relative to the pedestal. A knuckle boom assembly is attached to the crane housing and includes a main boom and a spreader type jib. A hoisting system includes a first departure sheave and a second departure sheave on the jib, and a third departure sheave mounted to the main boom or to the crane housing. One or more winches drive a first, second, and third cable which are each connected to an object suspension device and each pass via the first, second, and third departure sheave, respectively, to the respective winch. The first, the second, and the third cable together define an inverted pyramid which diverges upwards from the object suspension device when handling the object.

A hoisting arrangement for hoisting an offshore wind turbine blade, comprising a gripper attachment 150 arranged to be connected to the wind turbine blade, comprising a set of cable attachment points 191, 192,193 arranged as a first polygon, a vessel attachment module 194 arranged to be connected to a vessel, comprising a plurality of cable guide elements 190 arranged as a second polygon, a plurality of cables 141, 142, 143, 144 spanned between the cable attachment points and the cable guide elements, and a control system for controlling a position and/or orientation of the gripper attachment within a work space by controlling a spanned length of at least two cables of the plurality of cables between the cable attachment points and the cable guide elements.

A mobile crane having a main jib that can be raised and lowered but not telescoped by means of at least one main tensile connector, and a counter jib, where the main tensile connector extends between a first connection point in the region of a head of the main jib and a second connection point in the region of a head of the counter jib, a first secondary tensile connector and a second secondary tensile connector are arranged between the main tensile connector and the main jib, and the first secondary tensile connector has a fixed length. In order to further reduce the loads acting upon the main jib, such as during raising and lowering, and to increase its overall bearing load, at least portions of the second secondary tensile connector can be varied in length.

Provided are a crane capable of improving the workability for lowering and raising a strut, and a method for assembling and disassembling the crane. The crane includes a boom including a boom distal end part, a jib including a jib proximal end part, a strut connected to the boom distal end part or the jib proximal end part and raisable and lowerable by vertically rotationally movement about a strut rotation center; a winch, a winch rope wound and delivered by the winch; and a strut support unit attached to the jib back surface or the strut front surface. The strut support unit supports the strut in a fallen posture at a raisable position above the jib in a boom-and-jib fallen state. In the raisable position, a rope connection part to which the rope is connected in the strut is higher than the strut rotation center.

A hoisting arrangement for hoisting an offshore wind turbine blade, comprising a gripper attachment 150 arranged to be connected to the wind turbine blade, comprising a set of cable attachment points 191, 192,193 arranged as a first polygon, a vessel attachment module 194 arranged to be connected to a vessel, comprising a plurality of cable guide elements 190 arranged as a second polygon, a plurality of cables 141, 142, 143, 144 spanned between the cable attachment points and the cable guide elements, and a control system for controlling a position and/or orientation of the gripper attachment within a work space by controlling a spanned length of at least two cables of the plurality of cables between the cable attachment points and the cable guide elements.