A crane, in particular a mobile crane, includes a crane jib which can be moved about a substantially horizontal luffing axis, and a tensioning device for the crane jib. The tensioning device includes two pendants which run from the jib tip to the jib base of the crane jib and tensioning posts each tensioning a respective one of the pendants relative to the crane jib in a triangular configuration. In order to operate the crane, a luffing angle of the crane jib about the luffing axis is measured or recorded, and a spread angle between the tensioning posts while the crane jib is being used is modified depending on the luffing angle.

A crane, in particular a mobile crane, includes a crane jib which can be moved about a substantially horizontal luffing axis, and a tensioning device for the crane jib. The tensioning device includes two pendants which run from the jib tip to the jib base of the crane jib and tensioning posts each tensioning a respective one of the pendants relative to the crane jib in a triangular configuration. In order to operate the crane, a luffing angle of the crane jib about the luffing axis is measured or recorded, and a spread angle between the tensioning posts while the crane jib is being used is modified depending on the luffing angle.

The invention relates to a mobile crane having a telescopic boom that is luffably coupled to a superstructure and that comprises a coupling section and at least one telescopic section supported therein in a retractable and extendable manner. At least one guying support is fastened to the coupling section and is connected to the coupling section or to the superstructure via a first guying and to a connection piece at a telescopic section via a second guying. In accordance with the invention, the second guying comprises at least two guying elements coupled with one another. The second guying is thereby adjustable in length and is thus adaptable to the extension length of the telescopic boom such that at least one of the mutually coupled guying elements is directly releasably connectable to the guying support. The invention further relates to a guying system for a mobile crane in accordance with the invention, to a method of moving a mobile crane in accordance with the invention into a guyed work position, and to a method of varying the extension length of the guyed telescopic boom of a mobile crane in accordance with the invention.

The disclosure relates to a mobile crane, such as a crawler crane, comprising an undercarriage having a traveling gear, a superstructure rotatably supported about a vertical axle on the undercarriage, a boom connected in an articulated manner to the superstructure pivotable about a horizontal axle, an A frame connected to the boom via a guying means, and a retraction mechanism by means of which the A frame is pivotable. In accordance with the disclosure, the A frame is separable and comprises a pole connected in an articulated manner to the superstructure and a folding pole releasably connected to the pole.

A telescopic jib bracing unit for a mobile crane includes a holding frame which is embodied for fastening to the telescopic jib of the mobile crane and exhibits an open cross-section, the cross-sectional opening of which enables the jib to be retracted into the holding frame, and two bracing supports which are connected by the holding frame to form a structural unit. Two frame parts which form the open cross-section of the holding frame are coupled to each other via a coupling point such that they can be moved with respect to each other. A bracing unit transport system, a mobile crane and a fitting method are also provided.

The disclosure relates to a mobile crane, such as a crawler crane, comprising an undercarriage having a traveling gear, a superstructure rotatably supported about a vertical axle on the undercarriage, a boom connected in an articulated manner to the superstructure pivotable about a horizontal axle, an A frame connected to the boom via a guying means, and a retraction mechanism by means of which the A frame is pivotable. In accordance with the disclosure, the A frame is separable and comprises a pole connected in an articulated manner to the superstructure and a folding pole releasably connected to the pole.

A telescopic jib includes a main box, at least one inner box and at least one swing-out mast. The mast is arranged on the inner box such that the inner box is able to be pushed into the main box together with the mast in a swung-in or folded-in position to thereby provide a telescopic jib that more easily provides an increased load-bearing capacity. In a particular configuration such a telescopic jib is disposed on a vehicle crane having wheels, axles, a lower carriage and a superstructure, with the telescopic jib mounted to the superstructure.

A method for up-ending a longitudinal structure, being one of a foundation of an offshore wind turbine or a wind turbine tower to be installed on top of a previously installed foundation, wherein use is made of a crane The method includes providing a longitudinal structure with an upper end and a lower end in a substantially horizontal orientation; connecting the middle hoisting block of three main hoisting systems and one outer hoisting block of the three main hoisting systems to the upper end of the longitudinal structure; connecting another other outer hoisting block of the three main hoisting systems to the lower end of the longitudinal structure; and operating respective winches of the three main hoisting systems until the longitudinal structure is in a substantially vertical orientation with the upper end above the lower end.

A crane having a luffing jib and a lifting cylinder includes a cylinder body and a movable rod hinged on the jib to raise and lower the jib, and a locking device adapted to cooperate with the lifting cylinder to mechanically lock the rod in a deployed holding position and block the jib in a raised holding configuration, and further including a spacer hinged on the jib and supporting an abutment, the spacer configured for pivoting between a release position wherein the spacer is offset, authorizing the movable rod to be displaced freely, and a locking position wherein the spacer is folded so that the abutment is able to bear on the cylinder body to fixedly maintain the movable rod in the deployed holding position.

A crane includes a luffing jib and a lifting cylinder having a cylinder body and a movable rod hinged on the jib to displace the jib in lifting motion and in lowering motion, and a locking device adapted to cooperate with the lifting cylinder to mechanically lock the rod in a deployed holding position and block the jib in a raised holding configuration. The crane further includes a spacer hinged on the jib and supporting a stop, the spacer pivotable between a release position in which the spacer is shifted, allowing the movable rod to be freely displaced, and a locking position in which the spacer is folded so that the stop is capable of abutting on a bearing surface in a ball jointed connection with the cylinder body, to fixedly hold the movable rod in the deployed holding position.