This work machine includes: an actuator that extends and retracts a telescopic boom; an electric drive source that is provided in the actuator and drives using power supplied from a power source; an operating unit that operates based on power of the electric drive source; an electric circuit capable of switching between a drive state in which a supply of power from the power source to the electric drive source is allowed to drive the electric drive source, and a braking state in which the supply of power from the power source to the electric drive source stops to generate a braking force to be applied to the electric drive source; and a control unit that controls the switching between the drive state and the braking state.

An aircraft mounted cargo lifting crane and adapter for mounting the same is disclosed. The adapter includes a plate portion and several upstanding webs extending from the plate portion. The upstanding webs include perimeter webs that protect the bolted connections to the aircraft floor, and interior webs that are configured to surround the base of a crane. The adapter further includes a plurality of foot pads that have a slotted hole passing through the same, and a plurality of retractable wheels. A crane system is provided which includes the adapter and a crane, such as a jib crane, that is joined to the adapter. The crane system can be movably joined to different attachment points on the floor of the cargo bay of an aircraft.

Provided is a long arm supported in a cantilever manner with light weight and high rigidity. The rod 30 is formed from rods 31-33 so as to be a multi-stage telescopic configuration. The rods 32, 33 respectively have upright columns 42, 43 on the tips. The wire 11 is suspended between the tip of the rod 31 and the lead end of the arm via the top of the column 42. The wire 12 is suspended between the base of the column 42 and the lead end of the arm via the top of the column 42. The wire 22 is suspended between the top of the column 42 and the lead end of the arm via the top of the column 43. The tension generation means 50 pulls the wires 10, 20. The air pressure generation means 60 applies pressure to the inside of the rod 30.

Implementations of cranes may include a first telescoping boom and a second telescoping boom coupled within the first telescoping boom. The second telescoping boom may be entirely within the first telescoping boom when the second telescoping boom is in a fully extended position.