Tie-back system for cranes, in particular heavy load offshore cranes

Abstract

The invention relates to a tie-back system for a crane comprising a rotatable base with a generally vertical support frame and a lifting arm which is with a lower end hingedly connected to the base in a hinge point, an upper part of the frame carrying a displacement member movable relative to the frame, the displacement member carrying a first cable guide means, a first cable extending from a first connection point on the arm along the first cable guide means to a first pulling device. The displacement member comprising a tie connection point for connection to a tie member, a second cable guide means attached to an upper part of the frame and a second cable extending from a second connection point on the arm along the second cable guide means to a second pulling device. The frame comprising a stop part situated near the displacement member, wherein in a load transfer position the displacement member engages with the stop part for transferring a load on the first cable guide means to the frame, the displacement member in a tie-back position being disengaged from the stop part for transferring a load on the first cable guide means to a tie member which in the tie-back position is one side attached to a connection point at a distance from hinge point of the lifting arm, and on the other side to the tie connection point of the displacement member.