Slewing Wind Torque — Slewing Wind Torque
Wind torque about the slew axis from load sail area and radius — why downwind slews run away.
Wind on the jib and load resists (or drives) slewing — the torque is wind force times radius. Operators feel it as the slew that won't stop downwind: the motor's torque must exceed the wind's, and at long radius with a sail load it sometimes barely does. This number explains that feel.
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.
Wind torque about the slew axis from load sail area and radius — why downwind slews run away. A free crane load, wind & rigging safety tool — no sign-up, no upload, instant results in your browser.
About Slewing Wind Torque — Slewing Wind Torque
Slewing Wind Torque — Slewing Wind Torque computes the governing relationship T = ½ρv²·Cd·A × r live as you type. Wind on the jib and load resists (or drives) slewing — the torque is wind force times radius. Operators feel it as the slew that won't stop downwind: the motor's torque must exceed the wind's, and at long radius with a sail load it sometimes barely does. This number explains that feel. 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 Slewing Wind Torque — Slewing Wind Torque
- 1Enter your values — Wind speed, Load sail area, Drag coefficient, Working radius (sensible defaults are pre-filled).
- 2Read the live results: Wind force on load, Torque about slew axis.
- 3Check the "with your numbers" line to see T = ½ρv²·Cd·A × r substituted step by step.
- 4Adjust inputs until the scenario matches yours, then copy or share the result.
Why use Slewing Wind Torque — Slewing Wind Torque?
- ✓Instant, free and private — every calculation runs client-side in your browser; nothing is uploaded
- ✓Built on the stated formula T = ½ρv²·Cd·A × r with authoritative sources cited on the page (EN 13001 / EN 14439 — Crane design & tower crane standards; ASME B30.5/B30.9/B30.20 — Cranes, slings and below-the-hook devices)
- ✓Wind on the jib and load resists (or drives) slewing — the torque is wind force times radius.
- ✓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 slewing wind torque — slewing wind torque use?+
It evaluates T = ½ρv²·Cd·A × r, exactly as published. Sources: EN 13001 / EN 14439 — Crane design & tower crane standards; ASME B30.5/B30.9/B30.20 — Cranes, slings and below-the-hook devices. 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?+
Wind on the jib and load resists (or drives) slewing — the torque is wind force times radius. 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?+
Wind torque about the slew axis from load sail area and radius. Operators feel it as the slew that won't stop downwind: the motor's torque must exceed the wind's, and at long radius with a sail load it sometimes barely does. 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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