Lift Planning — Spreader Beam Compression
Spreader Beam Compression for engineered lift planning.
A spreader bar is a column lying down: the top slings squeeze it lengthwise, and the squeeze grows as the top angle flattens — at 30° the compression EQUALS the load times 1.7. Bars are rated at a stated angle for this reason; flatter rigging silently re-rates the bar downward as a strut.
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.
Spreader Beam Compression for engineered lift planning. A free crane load, wind & rigging safety tool — no sign-up, no upload, instant results in your browser.
About Lift Planning — Spreader Beam Compression
Lift Planning — Spreader Beam Compression computes the governing relationship T = W/(2sinθ) · C = 2T·cosθ = W/tanθ live as you type. A spreader bar is a column lying down: the top slings squeeze it lengthwise, and the squeeze grows as the top angle flattens — at 30° the compression EQUALS the load times 1.7. Bars are rated at a stated angle for this reason; flatter rigging silently re-rates the bar downward as a strut. 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 Lift Planning — Spreader Beam Compression
- 1Enter your values — Load weight, Top sling angle from horizontal (sensible defaults are pre-filled).
- 2Read the live results: Beam compression, Top sling tension (each).
- 3Check the "with your numbers" line to see T = W/(2sinθ) · C = 2T·cosθ = W/tanθ substituted step by step.
- 4Adjust inputs until the scenario matches yours, then copy or share the result.
Why use Lift Planning — Spreader Beam Compression?
- ✓Instant, free and private — every calculation runs client-side in your browser; nothing is uploaded
- ✓Built on the stated formula T = W/(2sinθ) · C = 2T·cosθ = W/tanθ with authoritative sources cited on the page (ASME B30.5/B30.9/B30.20 — Cranes, slings and below-the-hook devices; OSHA 29 CFR 1926 Subpart CC — Cranes & derricks in construction; DNV-ST-N001 — Marine operations (DAF methodology))
- ✓A spreader bar is a column lying down: the top slings squeeze it lengthwise, and the squeeze grows as the top angle flattens — at 30° the compression EQUALS the load times 1.7.
- ✓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 lift planning — spreader beam compression use?+
It evaluates T = W/(2sinθ) · C = 2T·cosθ = W/tanθ, exactly as published. Sources: ASME B30.5/B30.9/B30.20 — Cranes, slings and below-the-hook devices; OSHA 29 CFR 1926 Subpart CC — Cranes & derricks in construction; DNV-ST-N001 — Marine operations (DAF methodology). 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?+
A spreader bar is a column lying down: the top slings squeeze it lengthwise, and the squeeze grows as the top angle flattens — at 30° the compression EQUALS the load times 1.7. 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?+
Spreader Beam Compression for engineered lift planning. A free crane load, wind & rigging safety tool. Bars are rated at a stated angle for this reason; flatter rigging silently re-rates the bar downward as a strut. 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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