Abstract: A crane attachment includes a jib support device that supports, from rear, a jib that takes a forward tilted posture with respect to a boom when the boom takes a raised posture. The jib support device includes a link restraint tool configured to be capable of restraining a jib support line connecting link in a jib support line connecting link fixed posture that is a predetermined rotation posture with respect to a strut distal end portion and of restraining a strut support line connecting link in a strut support line connecting link fixed posture that is a predetermined rotation posture with respect to the strut distal end portion.

Abstract: A crane includes a strut guyline stretched between a lying lower portion, which is a portion located at a lower portion of a boom in a state where the boom and a jib are arranged in a lying attitude, and a strut, the strut guyline including a boom-side connection portion that is an end portion connected to the lying lower portion of the boom, in which a plurality of connectors includes a specific connector that is a connector arranged at a position corresponding to the lying lower portion, the plurality of coupling pins includes a specific coupling pin used in the specific connector, and the specific coupling pin or the specific connector includes a guyline attachment portion which is a portion to which the boom-side connection portion of the strut guyline is detachably attached.

Abstract: A backstop to prevent contact between a spacer and a peripheral member includes a rear jib backstop for a crane, having an outer cylinder, an inner cylinder, a spacer, a spacer holder and a lock mechanism. The spacer holder supports the spacer pivotally and swingably about an axis thereof and allows the spacer to fit on the inner cylinder, to keep the rear jib backstop from contracting in accordance with a change in a posture of the rear jib backstop when a boom rises. The lock mechanism enables locking of the spacer in such a manner as to keep the spacer from swinging about a swing central axis in a state where the spacer is located away from an outer surface of the inner cylinder.

Abstract: Provided are a crane enabling workability to be improved about connecting a guyline for interconnecting a strut and a boom to the boom, and a crane assembly method. A rope tip part of a winch rope is connected to an intermediate member in a state where a boom and a jib have been fallen on the ground. A winch performs a winding motion of winding the winch rope, thereby raising a strut and making the intermediate member approach a guyline connection part of the boom to allow a boom connection end part of a second guyline that is connected to the intermediate member to be connected to the guyline connection part.

Abstract: Provided are a crane capable of improving the workability for lowering and raising a strut, and a method for assembling and disassembling the crane. The crane includes a boom including a boom distal end part, a jib including a jib proximal end part, a strut connected to the boom distal end part or the jib proximal end part and raisable and lowerable by vertically rotationally movement about a strut rotation center; a winch, a winch rope wound and delivered by the winch; and a strut support unit attached to the jib back surface or the strut front surface. The strut support unit supports the strut in a fallen posture at a raisable position above the jib in a boom-and-jib fallen state. In the raisable position, a rope connection part to which the rope is connected in the strut is higher than the strut rotation center.

Abstract: A damage estimation device includes: an operation parameter reception unit that acquires an operation parameter related to an operation of a work machine; a damage estimation model storage unit that stores a damage estimation model constructed by machine learning using training data with the operation parameter as an input value and a damage parameter related to damage in a predetermined portion of the work machine as an output value; and a damage parameter estimation unit that estimates the damage parameter by inputting the operation parameter acquired by the operation parameter reception unit to the damage estimation model stored in the damage estimation model storage unit.

Abstract: A backstop to prevent contact between a spacer and a peripheral member includes a rear jib backstop for a crane, having an outer cylinder, an inner cylinder, a spacer, a spacer holder and a lock mechanism. The spacer holder supports the spacer pivotally and swingably about an axis thereof and allows the spacer to fit on the inner cylinder, to keep the rear jib backstop from contracting in accordance with a change in a posture of the rear jib backstop when a boom rises. The lock mechanism enables locking of the spacer in such a manner as to keep the spacer from swinging about a swing central axis in a state where the spacer is located away from an outer surface of the inner cylinder.

Abstract: A crane includes a jib posture retention device that retains a jib in a frontward tilt posture to a boom. The jib posture retention device includes a jib mast that holds a rope connection part at a tensioning position separate from a jib proximal end and a boom distal end backward thereof to render a jib-side support rope and a boom-side support rope linearly tensioned with the jib in the frontward tilt posture. The jib mast is shiftable to a tension form of holding the rope connection part at a tensioning position in an uprise posture and a looseness allowing form of locating the rope connection part at a looseness allowing position closer to the boom distal end than the tensioning position and closer to the jib proximal end than the tensioning position to allow the jib-side support rope and the boom-side support rope to be loosened.

Abstract: A damage estimation device includes: an operation parameter reception unit that acquires an operation parameter related to an operation of a work machine; a damage estimation model storage unit that stores a damage estimation model constructed by machine learning using training data with the operation parameter as an input value and a damage parameter related to damage in a predetermined portion of the work machine as an output value; and a damage parameter estimation unit that estimates the damage parameter by inputting the operation parameter acquired by the operation parameter reception unit to the damage estimation model stored in the damage estimation model storage unit.