This crane is provided with a counterweight which includes an engaging part, a swivel body which is configured to be capable of swiveling, and a fixing unit which is provided on the swivel body, includes an engaged part that can connect with the engaging part, and can adopt a front position and a rear position; in each of the front position and the rear position, the fixing unit and the counterweight are linked by the engaged part being arranged in a position corresponding to that of the engaging part and being connected to the engaging part.

This crane is provided with a counterweight which includes an engaging part, a swivel body which is configured to be capable of swiveling, and a fixing unit which is provided on the swivel body, includes an engaged part that can connect with the engaging part, and can adopt a front position and a rear position; in each of the front position and the rear position, the fixing unit and the counterweight are linked by the engaged part being arranged in a position corresponding to that of the engaging part and being connected to the engaging part.

A pipelayer machine may comprise a machine chassis; an operator cabin supported by the machine chassis; an engine supported by the machine chassis; and a boom coupled to the machine chassis. The operator cabin may include a seat assembly. The operator cabin may be stationary with respect to the machine chassis. The pipelayer machine may comprise a front portion and a rear portion. The engine may be provided in the rear portion. The boom may be provided forward with respect to the seat assembly.

An operator cabin may include a frame; a seat assembly supported by the frame; and one or more operator controls to control one or more components of a pipelayer machine, the operator controls being supported by the frame. The frame includes a front surface; a rear surface opposite the front surface; a first lateral surface; and a second lateral surface opposite the first lateral surface. The front surface may comprise a first front support structure and a second front support structure opposite the first front support structure. The rear surface may comprise a first rear support structure and a second rear support structure opposite the first rear support structure. A first distance between the first rear support structure and the second rear support structure may exceed a second distance between the first front support structure and the second front support structure.

An operator cabin may include a frame; a seat assembly supported by the frame; and one or more operator controls to control one or more components of a pipelayer machine, the operator controls being supported by the frame. The frame includes a front surface; a rear surface opposite the front surface; a first lateral surface; and a second lateral surface opposite the first lateral surface. The front surface may comprise a first front support structure and a second front support structure opposite the first front support structure. The rear surface may comprise a first rear support structure and a second rear support structure opposite the first rear support structure. A first distance between the first rear support structure and the second rear support structure may exceed a second distance between the first front support structure and the second front support structure.

A pipelayer machine may comprise a machine chassis; a towing winch assembly coupled to the machine chassis; an operator cabin supported by the machine chassis; an engine supported by the machine chassis; and a boom coupled to the machine chassis. The pipelayer machine may comprise a front portion and a rear portion. The towing winch assembly may be provided in the front portion of the pipelayer machine. The operator cabin may be provided between the towing winch assembly and the engine.

A pipelayer machine may comprise a machine chassis; a towing winch assembly coupled to the machine chassis; an operator cabin supported by the machine chassis; an engine supported by the machine chassis; and a boom coupled to the machine chassis. The pipelayer machine may comprise a front portion and a rear portion. The towing winch assembly may be provided in the front portion of the pipelayer machine. The operator cabin may be provided between the towing winch assembly and the engine.

A mobile pipelayer machine includes a machine chassis having a forward end, a rear end, a first side, and a second side, and a boom extending from the first side of the machine chassis. The mobile pipelayer machine also includes a movable counterweight system extending from the second side of the machine chassis, the movable counterweight system being selectively movable to change a center of gravity of the machine in at least one of a forward or a rearward direction.

A mobile pipelayer machine includes a machine chassis having a forward end, a rear end, a first side, and a second side, and a boom extending from the first side of the machine chassis. The mobile pipelayer machine also includes a movable counterweight system extending from the second side of the machine chassis, the movable counterweight system being selectively movable to change a center of gravity of the machine in at least one of a forward or a rearward direction.

The invention relates to a method of monitoring the safety of a crane, in particular of a revolving tower crane having a revolving deck, wherein the crane has a sensor system and a crane control, and wherein furthermore at least one tilt sensor is provided. In accordance with the invention, the at least one tilt sensor is attached to the revolving deck of the revolving tower crane, with the monitoring of the crane safety taking place at least during the putting up and/or taking down of the revolving tower crane.