More information from O*NET OnLine:

Crane and Tower Operators - 53-7021.00

O*NET-SOC Description

Operate mechanical boom and cable or tower and cable equipment to lift and move materials, machines, or products in many directions.

53-0000	Transportation and Material Moving Occupations
53-7000	Material Moving Workers
53-7020	Crane and Tower Operators
53-7021.00	Crane and Tower Operators

47-2072.00	Pile Driver Operators
47-2073.00	Operating Engineers and Other Construction Equipment Operators
47-5022.00	Excavating and Loading Machine and Dragline Operators, Surface Mining
47-5041.00	Continuous Mining Machine Operators
47-5044.00	Loading and Moving Machine Operators, Underground Mining
49-3042.00	Mobile Heavy Equipment Mechanics, Except Engines Bright Outlook
49-9096.00	Riggers
53-7041.00	Hoist and Winch Operators
53-7051.00	Industrial Truck and Tractor Operators
53-7121.00	Tank Car, Truck, and Ship Loaders

Clean, lubricate, and maintain mechanisms such as cables, pulleys, or grappling devices, making repairs, as necessary.
Determine load weights and check them against lifting capacities to prevent overload.
Direct helpers engaged in placing blocking or outrigging under cranes.
Direct truck drivers backing vehicles into loading bays and cover, uncover, or secure loads for delivery.
Inspect and adjust crane mechanisms or lifting accessories to prevent malfunctions or damage.
Inspect bundle packaging for conformance to regulations or customer requirements, and remove and batch packaging tickets.
Inspect cables or grappling devices for wear and install or replace cables, as needed.
Load or unload bundles from trucks, or move containers to storage bins, using moving equipment.
Move levers, depress foot pedals, or turn dials to operate cranes, cherry pickers, electromagnets, or other moving equipment for lifting, moving, or placing loads.
Review daily work or delivery schedules to determine orders, sequences of deliveries, or special loading instructions.
Weigh bundles, using floor scales, and record weights for company records.

Clean machinery or equipment.
Direct material handling or moving activities.
Inspect material-moving equipment to detect problems.
Inspect work to ensure standards are met.
Install parts, assemblies, or attachments in transportation or material handling equipment.
Load shipments, belongings, or materials.
Maintain material moving equipment in good working condition.
Operate cranes, hoists, or other moving or lifting equipment.
Record operational or production data.
Review work orders or schedules to determine operations or procedures.
Secure cargo.
Signal others to coordinate vehicle movement.
Verify information or specifications.
Weigh materials to ensure compliance with specifications.