WorkSafeBC Warns of Failing Tower Crane Gearboxes
October 11, 2016 – WorkSafeBC warns employers to make sure tower-crane equipment is properly inspected after near accidents from failing gearboxes. In an August bulletin, agency officials recommend that contractors regularly inspect and maintain all tower-crane gearboxes according to the manufacturer’s instructions, reports the Journal of Commerce.
Contractors should also seek written confirmation of the equipment’s fitness for service from an engineer or a person designated as qualified by the manufacturer, states WorkSafeBC.
A tower-crane operator had just finished hoisting formwork from the upper level of a high rise, and was hoisting the load block while advancing the trolley toward the mast. The empty hook, load block, and rigging chains, totaling about 1,000 lbs., plummeted to the ground with the load line spooling around them. Though construction crews were working in close proximity to the falling equipment, no one was injured. Hoisting gearbox inspection found a gear had broken in half during operation. Subsequent lab tests showed the gear was made of defective metal.
WorkSafeBC advises contractors to:
- Develop and implement an inspection and preventive maintenance program for all gearboxes in the absence of a manufacturer’s inspection criteria. Pay particular attention to signs of gear fatigue or cracking, using X-rays or magnetic-particle testing to detect hidden flaws.
- Repair or replace damaged or defective parts immediately, and have repairs certified by a professional engineer or manufacturer.
- Keep detailed reports of gearbox tests, inspections, maintenance, repairs and modifications, and pre-start inspections for the service life of the equipment.
- Keep the equipment logbook up to date. Make the logbook available on request to workers, supervisors, the operator, and the person responsible for inspecting, testing, or maintaining it, as well as anyone else on the site.
