Sling Tension — 4-Leg Bridle
Per-leg tension for a 4-leg bridle from load, sling angle and hitch efficiency.
Four legs sounds like quarter-share each — but rigid loads really hang on two diagonal legs while the others stabilize, which is why this calculator (like ASME practice) divides by 3, not 4. Only truly flexible loads spread across all four.
Formula
Note: Rigging and crane decisions are life-safety critical. This calculator is a planning aid — the load chart, sling tags, site lift plan and a qualified lift director govern every real lift.
Per-leg tension for a 4-leg bridle from load, sling angle and hitch efficiency. A free crane load, wind & rigging safety tool — no sign-up, no upload, instant results in your browser.
About Sling Tension — 4-Leg Bridle
Sling Tension — 4-Leg Bridle computes the governing relationship T = W / (n · sinθ) · required WLL = T ÷ hitch efficiency live as you type. Four legs sounds like quarter-share each — but rigid loads really hang on two diagonal legs while the others stabilize, which is why this calculator (like ASME practice) divides by 3, not 4. Only truly flexible loads spread across all four. Defaults are pre-filled with realistic values for this exact scenario, and the worked example substitutes your numbers step by step so the math is never a black box.
How to use Sling Tension — 4-Leg Bridle
- 1Enter your values — Load weight, Sling angle from horizontal, Load-bearing legs, Hitch efficiency (sensible defaults are pre-filled).
- 2Read the live results: Tension per leg, Min sling WLL per leg, Angle multiplier.
- 3Check the "with your numbers" line to see T = W / (n · sinθ) · required WLL = T ÷ hitch efficiency substituted step by step.
- 4Adjust inputs until the scenario matches yours, then copy or share the result.
Why use Sling Tension — 4-Leg Bridle?
- ✓Instant, free and private — every calculation runs client-side in your browser; nothing is uploaded
- ✓Built on the stated formula T = W / (n · sinθ) · required WLL = T ÷ hitch efficiency with authoritative sources cited on the page (ASME B30.5/B30.9/B30.20 — Cranes, slings and below-the-hook devices; Wire Rope Technical Board — Wire Rope Users Manual, 4th ed.)
- ✓Four legs sounds like quarter-share each — but rigid loads really hang on two diagonal legs while the others stabilize, which is why this calculator (like ASME practice) divides by 3, not 4.
- ✓SI ⇄ Imperial toggle converts your inputs in place, so you can work in the units your drawings use
Frequently asked questions
What formula does the sling tension — 4-leg bridle use?+
It evaluates T = W / (n · sinθ) · required WLL = T ÷ hitch efficiency, exactly as published. Sources: ASME B30.5/B30.9/B30.20 — Cranes, slings and below-the-hook devices; Wire Rope Technical Board — Wire Rope Users Manual, 4th ed.. The substituted worked example on the page lets you verify every step against the textbook.
How should I read the result — and how far can I trust it?+
Four legs sounds like quarter-share each — but rigid loads really hang on two diagonal legs while the others stabilize, which is why this calculator (like ASME practice) divides by 3, not 4. Rigging and crane decisions are life-safety critical. This calculator is a planning aid — the load chart, sling tags, site lift plan and a qualified lift director govern every real lift.
When is this calculator the right tool for the job?+
Per-leg tension for a 4-leg bridle from load, sling angle and hitch efficiency. A free crane load, wind & rigging safety tool. Only truly flexible loads spread across all four. For neighbouring scenarios, the related tools below cover the same engine with different presets.
Does it support both metric and imperial units?+
Yes — the SI ⇄ Imperial toggle converts the values already in the fields, preserving the physical quantity, so you can flip mid-calculation without re-entering anything.
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