Lift Planning — Lift Window Planning
Lift Window Planning for engineered lift planning.
The dangerous wind decision isn't starting a lift over the limit — nobody does that — it's starting a 45-minute lift with 20 minutes of weather window. Once the load is off the deck there is no pause button; this calculator forces the forecast TREND into the go/no-go, where it belongs.
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.
Lift Window Planning 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 — Lift Window Planning
Lift Planning — Lift Window Planning computes the governing relationship v_end = v_now + trend × duration; window = (limit − now)/trend live as you type. The dangerous wind decision isn't starting a lift over the limit — nobody does that — it's starting a 45-minute lift with 20 minutes of weather window. Once the load is off the deck there is no pause button; this calculator forces the forecast TREND into the go/no-go, where it belongs. 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 — Lift Window Planning
- 1Enter your values — Lift duration (hook-to-hook), Current gust, Forecast gust rise, Task wind limit (sensible defaults are pre-filled).
- 2Read the live results: Gust at lift end, Time until limit.
- 3Check the "with your numbers" line to see v_end = v_now + trend × duration; window = (limit − now)/trend substituted step by step.
- 4Adjust inputs until the scenario matches yours, then copy or share the result.
Why use Lift Planning — Lift Window Planning?
- ✓Instant, free and private — every calculation runs client-side in your browser; nothing is uploaded
- ✓Built on the stated formula v_end = v_now + trend × duration; window = (limit − now)/trend 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))
- ✓The dangerous wind decision isn't starting a lift over the limit — nobody does that — it's starting a 45-minute lift with 20 minutes of weather window.
- ✓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 — lift window planning use?+
It evaluates v_end = v_now + trend × duration; window = (limit − now)/trend, 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?+
The dangerous wind decision isn't starting a lift over the limit — nobody does that — it's starting a 45-minute lift with 20 minutes of weather window. 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?+
Lift Window Planning for engineered lift planning. A free crane load, wind & rigging safety tool. Once the load is off the deck there is no pause button; this calculator forces the forecast TREND into the go/no-go, where it belongs. 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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