Sling Tension — Two-Point Suspension Share
Reaction at each pick point of a beam from CG position — the seesaw rule with a planning margin.
Two pick points on a beam split load by inverse distance to the CG — the classic seesaw. The 10% planning margin this adds per point covers dynamic shift; tandem CRANE lifts (two hooks, two machines) add far stricter derates and an engineered plan on top.
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.
Disclaimer: This tool is for general informational and estimation purposes only and is not professional financial, tax, accounting or legal advice. All figures are estimates — verify with a qualified professional before making decisions. Read the full disclaimer.
Reaction at each pick point of a beam from CG position — the seesaw rule with a planning margin. A free crane load, wind & rigging safety tool — no sign-up, no upload, instant results in your browser.
About Sling Tension — Two-Point Suspension Share
Sling Tension — Two-Point Suspension Share computes the governing relationship R_A = W(L−x)/L · R_B = W·x/L, × dynamic margin live as you type. Two pick points on a beam split load by inverse distance to the CG — the classic seesaw. The 10% planning margin this adds per point covers dynamic shift; tandem CRANE lifts (two hooks, two machines) add far stricter derates and an engineered plan on top. 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 — Two-Point Suspension Share
- 1Enter your values — Total load, Distance between picks, CG from pick A, Dynamic margin (sensible defaults are pre-filled).
- 2Read the live results: Pick A design load, Pick B design load.
- 3Check the "with your numbers" line to see R_A = W(L−x)/L · R_B = W·x/L, × dynamic margin substituted step by step.
- 4Adjust inputs until the scenario matches yours, then copy or share the result.
Why use Sling Tension — Two-Point Suspension Share?
- ✓Instant, free and private — every calculation runs client-side in your browser; nothing is uploaded
- ✓Built on the stated formula R_A = W(L−x)/L · R_B = W·x/L, × dynamic margin 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.)
- ✓Two pick points on a beam split load by inverse distance to the CG — the classic seesaw.
- ✓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 — two-point suspension share use?+
It evaluates R_A = W(L−x)/L · R_B = W·x/L, × dynamic margin, 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?+
Two pick points on a beam split load by inverse distance to the CG — the classic seesaw. 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?+
Reaction at each pick point of a beam from CG position. The 10% planning margin this adds per point covers dynamic shift; tandem CRANE lifts (two hooks, two machines) add far stricter derates and an engineered plan on top. 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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