Estimation apparatus and crane

An estimation apparatus for estimating a number of wound layers of a wire rope, which is a number of layers of the wire rope wound around a winch drum, in a crane including a boom, the winch drum, and the wire rope wound around the winch drum, the estimation apparatus being mounted on the crane, the estimation apparatus comprising:

• a calculation unit that calculates a delivery length of the wire rope, which is a total length of the wire rope that is unwound and fed-out from the winch drum;
• a detection unit that detects a rotational amount of the winch drum;
• and
• a control unit that estimates the number of wound layers, based at least on a difference in the delivery length of the wire rope and a difference in the rotational amount of the winch drum between a first orientation and a second orientation of the boom,
• wherein the calculation unit, the detection unit, and the control unit are each implemented via at least one processor.