Tower Crane Operator Flashcards

Under OSHA 1926 Subpart CC, which foundation requirement applies to a tower crane before erection?

Answer: The foundation must be designed by a registered professional engineer capable of supporting all static and dynamic loads from the crane

OSHA 1926.1435(b) requires tower crane foundations to be designed by a registered PE to support all crane loads, including maximum static, dynamic, and environmental (wind) loads.

A tower crane's free-standing height limit is 180 feet. The project requires the hook to reach 250 feet. What must be done before exceeding the free-standing limit?

Answer: The tower crane must be tied to the structure with anchor ties at manufacturer-specified intervals before exceeding the free-standing height

Tower cranes have a maximum free-standing height. To operate taller, the tower must be anchored to the structure at intervals specified by the crane manufacturer, transferring lateral forces into the building.

What is the purpose of the tower crane's anti-collision system on a multi-crane jobsite?

Answer: To prevent two cranes from swinging into the same zone simultaneously, avoiding structural collision between booms, jibs, or loads

Anti-collision systems use sensors and zone management software to prevent overlap between operating envelopes of adjacent cranes, stopping or alerting operators before boom, jib, or load contact occurs.

Tower crane operators must verify wind speed before and during operations. At what wind speed must most tower cranes cease lifting operations?

Answer: At the manufacturer's maximum wind speed limit, typically 35 to 45 mph for operational use and lower for erection/dismantling

Tower crane manufacturers specify maximum wind speeds for different operation modes. Typical limits are 35-45 mph for load handling, with lower limits (often 20-28 mph) for erection, climbing, and dismantling.

During tower crane erection, OSHA requires the process to be directed by a qualified person. What qualifications define this person?

Answer: A person with recognized degree or professional knowledge, or extensive practical experience, who can identify and solve problems with erection equipment and methods

OSHA defines a qualified person as one with recognized degree, certificate, or professional standing, or extensive knowledge, training, and experience to successfully identify and correct safety hazards related to the subject matter.

A tower crane jib load chart shows 25,000 lb at minimum radius and 10,000 lb at maximum jib tip radius. A rigger wants to pick a 24,000-lb load at 80% of maximum jib length. What must the operator verify?

Answer: Locate the 80% radius row on the load chart and confirm the rated capacity at that exact radius equals or exceeds 24,000 lb

Tower crane capacity varies continuously with radius. The operator must look up the specific capacity at the 80% radius point. Being under the minimum-radius maximum does not mean the load is safe at other radii — each radius has its own rated load.