A crane for use on an offshore vessel is provided with a boom restrainer, wherein the boom restrainer is a hydro-pneumatic boom restrainer, for reducing upward pivoting of the boom, when the boom is in the top zone, wherein the boom restrainer includes: multiple hydraulic cylinders, each having a hydraulic circuit and a cylinder rod with a cylinder head, wherein the cylinders are mounted on the crane structure with the cylinder heads directed towards the boom of the crane, preferably are mounted on a stay of the crane structure, a catcher for each hydraulic cylinder, wherein each catcher is mounted on the boom and is configured for receiving the cylinder head of the corresponding hydraulic cylinder, and to lock the cylinder head, preferably pivotable locks the cylinder head, relative to the boom, when the boom pivots upwards in the top zone; a gas buffer for each hydraulic cylinder, wherein each gas buffer is mounted to the corresponding hydraulic cylinder, and is connected to the hydraulic circuit of the corresponding hydraulic cylinder via a medium separator, wherein the gas buffer forces the hydraulic cylinder in an extended position, and wherein the volume ratio between the hydraulic cylinder and the gas buffer is such that the hydraulic cylinder acts as a progressive spring, e.g. the gas buffers each have a size in the range of 1000-1400 litre, for example 1200 litre and the hydraulic cylinders each have a size in the range of 800-1000 litre, for example 900 litre, and preferably the ratio between the volume of the gas buffer and the volume of the associated hydraulic cylinder is 4:3.

A crane for use on an offshore vessel is provided with a boom restrainer, wherein the boom restrainer is a hydro-pneumatic boom restrainer, for reducing upward pivoting of the boom, when the boom is in the top zone, wherein the boom restrainer includes: multiple hydraulic cylinders, each having a hydraulic circuit and a cylinder rod with a cylinder head, wherein the cylinders are mounted on the crane structure with the cylinder heads directed towards the boom of the crane, preferably are mounted on a stay of the crane structure, a catcher for each hydraulic cylinder, wherein each catcher is mounted on the boom and is configured for receiving the cylinder head of the corresponding hydraulic cylinder, and to lock the cylinder head, preferably pivotable locks the cylinder head, relative to the boom, when the boom pivots upwards in the top zone; a gas buffer for each hydraulic cylinder, wherein each gas buffer is mounted to the corresponding hydraulic cylinder, and is connected to the hydraulic circuit of the corresponding hydraulic cylinder via a medium separator, wherein the gas buffer forces the hydraulic cylinder in an extended position, and wherein the volume ratio between the hydraulic cylinder and the gas buffer is such that the hydraulic cylinder acts as a progressive spring, e.g. the gas buffers each have a size in the range of 1000-1400 litre, for example 1200 litre and the hydraulic cylinders each have a size in the range of 800-1000 litre, for example 900 litre, and preferably the ratio between the volume of the gas buffer and the volume of the associated hydraulic cylinder is 4:3.

Hoists, platforms and davits are described as well as methods of securing same to telecommunication and other towers. The hoists, platforms and davits may be secured to the towers on a temporary basis using clamps. The clamps may include brackets and cables. The cables may be attached to the brackets, may wrap around the outer surface/perimeter of the tower pole/leg and may use tension to keep the bracket in place.

Hoists, platforms and davits are described as well as methods of securing same to telecommunication and other towers. The hoists, platforms and davits may be secured to the towers on a temporary basis using clamps. The clamps may include brackets and cables. The cables may be attached to the brackets, may wrap around the outer surface/perimeter of the tower pole/leg and may use tension to keep the bracket in place.

Hoists, platforms and davits are described as well as methods of securing same to telecommunication and other towers. The hoists, platforms and davits may be secured to the towers on a temporary basis using clamps. The clamps may include brackets and cables. The cables may be attached to the brackets, may wrap around the outer surface/perimeter of the tower pole/leg and may use tension to keep the bracket in place.

There is provided a method for controlling a crane, with which the position of a hook is automatically adjusted before lift-off, where a freely-derricking telescopic boom is provided to a swivel base, a main hook is suspended with a main wire rope from a distal end section of the telescopic boom, and a suspended load is suspended on a main hook with slinging wire ropes, wherein post-slinging lift-off is preceded by a hook position adjustment control involving repeating: a first process where the control device controls so as to reel in the main wire rope to a position where the main wire rope is tensed; and a second process where the control device controls so as to move the distal end section of the telescopic boom in the same direction of a horizontal direction component of the movement of the main hook in the first process.

A work machine includes a lower traveling body, an upper swing body swingably mounted on the lower traveling body, a work device attached to the upper swing body, a hook attached to the distal end of the work device, an acquisition device configured to acquire information on the conveying destination of a suspended load to be suspended from the hook, and an imaging device attached to the upper swing body and configured to acquire image information related to a situation in an area in front of, behind, and beside the upper swing body. The situation includes the state of the suspended load. The work machine is configured to automatically convey the suspended load to the conveying destination by causing at least one of the lower traveling body, the upper swing body, and the work device to operate.

This crane control device controls the operation of a boom and a winch and transports a load from a start point to an end point, the control device comprising: an acquisition unit that acquires position information of the start point and position information of the end point; a horizontal trajectory generation unit that, by using an optimal control theory, generates a horizontal trajectory for a distal-end part of the boom as represented by a horizontal-direction component of a straight line linking the start point and the end point; a movement trajectory generation unit that generates a trajectory of movement of the boom for transporting the load so as to follow the horizontal trajectory, and a trajectory of rotational movement of the winch; and a movement control unit that controls the boom and the winch based on the trajectory of movement of the boom and the winch.

This crane control device controls the operation of a boom and a winch and transports a load from a start point to an end point, the control device comprising: an acquisition unit that acquires position information of the start point and position information of the end point; a horizontal trajectory generation unit that, by using an optimal control theory, generates a horizontal trajectory for a distal-end part of the boom as represented by a horizontal-direction component of a straight line linking the start point and the end point; a movement trajectory generation unit that generates a trajectory of movement of the boom for transporting the load so as to follow the horizontal trajectory, and a trajectory of rotational movement of the winch; and a movement control unit that controls the boom and the winch based on the trajectory of movement of the boom and the winch.

A crane controller for a crane, in particular a cargo crane, has a first operating mode, in which the crane can be user-operated by control commands from an operator, and a second operating mode that can be activated by the operator. In the second operating mode, the crane geometry can be changed by the crane controller in a pre-defined sequence of movements. The crane controller has a menu-drive user interface, and the interface has a function which can be selected by the operator and by which the crane controller switches from the first to the second operating mode.