Chain / Lever Hoist Effort and Travel
Hand-pull effort, hand-chain travel for the lift, and a pass / fail against the rated WLL of a chain or lever hoist.
Example
You enter
- Load (lb) 2000
- Hoist rated WLL (lb) 2000
- Mechanical advantage 32
- Drivetrain efficiency 0.85
- Lift distance (ft) 4
You get
- Hand pull required 73.5 lb
- Hand-chain travel for the lift 128 ft
Details, formula, and sources
ASME B30.16 / B30.21; the rated WLL is the ceiling.
hand_pull = load / (mech_adv x efficiency); hand_chain_travel = lift x mech_adv; pass = load <= rated_wll.
ASME B30.16 (Overhead Hoists) and ASME B30.21 (Lever Hoists) by name; first-principles mechanical advantage with a drivetrain efficiency.
ASME B30.16 and B30.21 are published consensus standards. The mechanical-advantage relation is public.
Estimate. Head rigger and manufacturer working-load-limit charts govern. Inspect every piece of hardware before the show.
Field names used by the API: load_lb, rated_wll_lb, mech_adv, efficiency, lift_ft, hand_pull_lb, hand_chain_travel_ft
- Drivetrain efficiency 0.85 default (gear + chain-fall losses)hoist manufacturer data