In an offshore crane vessel with a crane, for example for use in the handling of one or more offshore wind turbine components, the crane includes a superstructure that is rotatable with respect to a pedestal, and a boom having a length of 60-200 meters. A boom luffing assembly is provided for pivoting the boom about a horizontal boom pivot axis. The crane further includes a main hoisting device for hoisting a load, including a main hoist block assembly supported by a head structure, wherein the head structure is a travelling head structure which is slidable along a part of the boom from the tip end to a second position on the boom.

The disclosure relates to an assembly head for a telescopic boom that can be separated into an inner and an outer boom set and that is reversibly mountable at an inner telescopic section of the outer boom set. The assembly head comprises a pulley head having deflection pulleys and a telescopic tube section that is arranged the pulley head, that can be pushed into the inner telescopic section from its end, and that has a substantially smaller length than the inner telescopic section. The disclosure further relates to a separable telescopic boom having an assembly head in accordance with the disclosure, to a mobile crane having a telescopic boom in accordance with the disclosure, and to a method for the self-assembly of an assembly head in accordance with the disclosure at the outer boom set of a telescopic boom.

The disclosure relates to an assembly head for a telescopic boom that can be separated into an inner and an outer boom set and that is reversibly mountable at an inner telescopic section of the outer boom set. The assembly head comprises a pulley head having deflection pulleys and a telescopic tube section that is arranged the pulley head, that can be pushed into the inner telescopic section from its end, and that has a substantially smaller length than the inner telescopic section. The disclosure further relates to a separable telescopic boom having an assembly head in accordance with the disclosure, to a mobile crane having a telescopic boom in accordance with the disclosure, and to a method for the self-assembly of an assembly head in accordance with the disclosure at the outer boom set of a telescopic boom.

The invention relates to an apparatus for weighing the hook load of a crane, wherein different measurement accuracies can be set at the apparatus, comprising at least one measurement device, at least one retaining pin, and at least one coupling section. The invention is additionally directed to a hook block and to a crane having a corresponding apparatus.

The invention relates to an apparatus for weighing the hook load of a crane, wherein different measurement accuracies can be set at the apparatus, comprising at least one measurement device, at least one retaining pin, and at least one coupling section. The invention is additionally directed to a hook block and to a crane having a corresponding apparatus.

A boom mountable breaker system and a method of using same for interrupting electrical transmission through a portion of an energized conductor downstream of a desired break location. The method includes: mounting the jumper onto the energized conductor across the desired break location so as to form an electrically conductive first parallel electrical path; installing an in-line opener in the energized conductor at the desired break location on the energized conductor; positioning the breaker at the desired break location on the energized conductor, and electrically connecting the breaker, while open, across the desired break location and across the opposite ends of the jumper so as to form a second parallel electrical path when the breaker is closed; closing the breaker to thereby complete the second parallel electrical path; removing the jumper from across the desired break location; and, opening and then removing the breaker.

A portable winch and method of use is shown. One advantage of winches shown includes an ability to lower a boom or boom sections into limited access exit pit for winching operations such as pipe bursting. Sectional boom designs shown provide the ability to easily raise and lower a boom large distances without the need for a single long boom. Selected winch designs shown include flexible inserts between the boom and the winch frame that help resist damage from unforeseen shifting of the device during operation. Designs and methods shown also include multiple pulleys on a boom end unit. Fasteners are shown that reduce build up of debris.

A portable winch and method of use is shown. One advantage of winches shown includes an ability to lower a boom or boom sections into limited access exit pit for winching operations such as pipe bursting. Sectional boom designs shown provide the ability to easily raise and lower a boom large distances without the need for a single long boom. Selected winch designs shown include flexible inserts between the boom and the winch frame that help resist damage from unforeseen shifting of the device during operation. Designs and methods shown also include multiple pulleys on a boom end unit. Fasteners are shown that reduce build up of debris.

A self-propelled vehicle used to lay pipe sections within trenches located on sloped terrain, and a method for using it, including: an undercarriage carrying a vehicle chassis and capable of climbing sloped terrain; a rotating platform which can be maintained level relative to the sloped terrain; and a boom with an angled boom head, capable of using two independent winch cables to lift and position individual pipe sections having differing lengths and diameters. The vehicle may be used to sequentially lift two or more pipe sections, one at a time, and to swing and position the pipe sections in a trench, end-to-end.

A photographing system for an ultralow-height counterweight-free vehicle-mounted jib, comprising a base (10), a rotating part, a jib, and a damping part. The rotating part comprises a housing (1) provided above the base (10), a frame (37), counterweight blocks (36), a servo electric cylinder (35), a motor (38), a pinion (40), and a large gear (41). The servo electric cylinder (35) is connected to a rapid abutting structure (2) by means of a clamping member (43). The rapid abutting structure (2) is connected to the jib. The other end of the jib is connected to a gimbal camera mounting plate (6) by means of the damping part. The damping part comprises damping springs (8) and a universal joint structure consisting of a pitch damping rod and left and right swing damping rods. A air spring (34) is provided between the frame (37) and the clamping member (43). One end of the air spring (34) is connected onto the clamping member (43), and the other end of the air spring (34) is connected onto the frame (37). A jib body is driven by the servo electric cylinder to perform a pitch motion, and the weight carried by the front end of the jib body is balanced by the air spring, so that the system is counterweight-free.