There is no single crane-capacity percentage that classifies every lift as critical. The threshold depends on the rule or procedure that governs the work.
For steel erection, OSHA defines a critical lift as one that exceeds 75% of the crane or derrick’s rated capacity or uses more than one crane or derrick under 29 CFR 1926.751. OSHA did not adopt that percentage as a general critical-lift trigger for all construction work. Owners, employers, government programs, and project procedures may use different capacity or consequence-based criteria.
When a procedure uses a percentage, compare the total load imposed on the crane with the rated capacity for the actual configuration and operating radius. Account for the load and any hook block, rigging, lifting device, or other component that the manufacturer’s load chart requires to be included. Capacity changes with boom length, radius, configuration, outrigger or crawler setup, and operating area.
Learn what changes when a load approaches the crane’s capacity or review our guide to planning a critical lift.