A tower crane includes a tower on which is pivotally mounted a boom displaceable between a lowered position and a raised position. The crane is configurable between a service configuration in which the boom is controlled in rotation and a weather vane configuration in which the boom is in the raised position and is released in rotation on the tower to allow orientation in the direction of the wind. A wind load system is mounted on the boom and is adjustable between a retracted shape in the service configuration providing a reduced surface exposed to the wind, and a deployed shape in the weather vane configuration providing an extended surface exposed to the wind. The wind load system is configured to move from the retracted shape to the deployed shape under the effect of its own weight alone (i.e., under gravity) when the boom is raised.

The invention relates to a method of weathervaning a work machine in out-of-operation mode, in particular of weathervaning a revolving crane/revolving tower crane or a concrete spreader mast, wherein the work machine comprises at least one slewing part that is rotatable about a substantially vertical axis by means of a slewing gear, and wherein in a first step one or more wind data are measured by means of a measurement system arranged at the work machine; an optimum position of the slewing part is determined for an optimum weathervaning in dependence on the detected wind data; and the slewing gear drive is subsequently correspondingly actuated to bring the slewing part into the determined position.

Tools, systems, and methods for use in conjunction with maintenance, assembly, rebuilding, or other procedures which involve displacing components of an assembly are disclosed. These tools, systems, and methods may be used in conjunction with a crane or other lifting device and may be configured to assemble, disassemble, or otherwise maintain components of an uptower gearbox.

A multi-component lattice mast section comprises a longitudinal axis, a plurality of chord elements extending along the longitudinal axis, a plurality of connection bars interconnecting in each case two adjacent chord elements, a lattice mast cross-sectional surface area with a lattice mast width and a lattice mast height, the lattice mast cross-sectional surface area being oriented perpendicular to the longitudinal axis, and at least two detachably interconnectable lattice mast assemblies, with each of the lattice mast assemblies having a lattice mast assembly width smaller than the lattice mast width and/or a lattice mast assembly height smaller than the lattice mast height, and with the connection bars being firmly connection to a chord element in a working arrangement.

A multi-component lattice mast section comprises a longitudinal axis, a plurality of chord elements extending along the longitudinal axis, a plurality of connection bars interconnecting in each case two adjacent chord elements, a lattice mast cross-sectional surface area with a lattice mast width and a lattice mast height, the lattice mast cross-sectional surface area being oriented perpendicular to the longitudinal axis, and at least two detachably interconnectable lattice mast assemblies, with each of the lattice mast assemblies having a lattice mast assembly width smaller than the lattice mast width and/or a lattice mast assembly height smaller than the lattice mast height, and with the connection bars being firmly connection to a chord element in a working arrangement.

The invention relates to a method of operating a crane having a luffable crane boom and having a trolley travelable at the crane boom, wherein the crane can be operated in a luffing mode, on the one hand, and in a trolley mode, on the other hand. In accordance with the invention, a switch is made between a luffing mode and a trolley mode by varying the hoist rope reeving. The invention further relates to such a crane for carrying out the method.

A boom assembly for a hoist may include a flat surface configured to elastically deform in response to a load on the hoist, and a strain sensor coupled to the flat surface and configured to generate an electronic signal.

A limited rotation slewing ring crane may include a pedestal, a column rotatively coupled, about a first rotation axis, to the pedestal by a slewing ring rotative coupling, and stops for limiting the relative rotation of the column with respect to the pedestal. The crane may also include a rotative sensor adapted to measure a rotation angle of the column with respect to the pedestal. The rotation sensor may include a tubular body axially extending from the base of the column, a stationary body connected to the pedestal and a wheel. A second rotation axis of the wheel may be offset with respect to a first rotation axis of the column with respect to the pedestal.

A davit assembly comprises a vertical structural column connecting a horizontal structural beam between a longer forward beam portion and a shorter rearward beam portion thereof, an angled support brace tensioned between a lower region of the structural column and an end of the shorter rearward beam portion and a primary rigging anchor slidably engaging the forward beam portion.

A portable hoist system has an adjustable support strut mechanism, allowing for compact storage and portability, with the entire assembly retained as one unit. In one embodiment the support strut mechanism, which is connected on one end to a boom and at another end to a bracket, is foldable and adjustable using an adjustment pin and holes along the two-piece support strut mechanism. In one preferred form of the invention a winch of the hoist system is field-adjustable as to position on the hoist's boom, to overcome problems of space constraints.