G. Safety Standards & Testing
Safe Working Load (SWL)
safe working load, SWL, stage machinery load rating
What is a Safe Working Load (SWL)?
Safe Working Load (SWL) is the maximum weight that a lifting device, component, or rigging system is approved to carry during normal operation, with the specified safety factor maintained. SWL is the number displayed on equipment rating plates and used for all load planning.
How It Works
SWL = Minimum Breaking Load (MBL) ÷ Safety Factor. For stage machinery (EN 17206): Wire rope components require safety factor ≥ 10:1, Chain components require ≥ 8:1, and Structural components require ≥ 5:1 (static). Example: A wire rope with a breaking strength of 10,000 kg ÷ safety factor 10 = SWL of 1,000 kg.