California Code, Labor Code - LAB § 7371

(a) “Crane” means a machine for lifting or lowering a load and moving it horizontally, in which the hoisting mechanism is an integral part of the machine. It may be driven manually or by power and may be a fixed or a mobile machine, but does not include stackers, lift trucks, power shovels, backhoes, excavators, concrete pumping equipment, or straddle type mobile boat hoists.

(b) “Straddle type mobile boat hoist” means a straddle type carrier supported by four wheels with pneumatic tires capable of straddling and carrying boats with high masts and superstructure.

(c) “Tower crane” means a crane in which a boom, swinging jib, or other structural member is mounted on a vertical mast or tower.

(d) “Mobile tower crane” means a tower crane which is mounted on a crawler, truck, or similar carrier for travel or transit.

(e) “Crane employer” means an employer who is responsible for the maintenance and operation of a tower crane.

(f) “Certificating agency” shall have the same definition as in Section 4885 of Title 8 of the California Code of Regulations.