Wind Speed Limits for Lifting

Wind speed is one of the most critical factors affecting the safety of all lifting operations on construction sites.
Most mobile cranes must cease operations when wind speeds reach 38 mph (17 m/s) at the working height.
Tower cranes typically have lower operating wind speed limits — often 45 mph (20 m/s) depending on the model.
Wind speed at ground level can be significantly lower than at the height of the boom or load — height corrections apply.
Large, flat loads such as cladding panels, steel decking, and precast wall panels act as sails in moderate wind.
Sail area loads may require stop-work at lower wind speeds than the crane's rated limit due to loss of load control.
Wind speed must be monitored continuously using an anemometer at or near the working height of the crane.
The appointed person or lift supervisor must make the decision to cease lifting when wind limits are approached.
Gusting conditions are often more dangerous than sustained wind — sudden gusts can exceed the steady-state speed dramatically.
The lift plan must specify the maximum wind speed for each lift, considering both crane limits and load characteristics.

Load swing	Wind causes suspended loads to swing unpredictably, striking structures and workers — higher wind means greater swing amplitude.
Sail area effect	Large flat loads catch wind disproportionately — a panel safe to lift in calm weather becomes uncontrollable in moderate wind.
Height amplification	Wind speed increases with altitude — ground-level readings significantly understate the conditions at the boom tip and load height.

Do

Don't

Monitor wind speed continuously using an anemometer at the working height.
Know the wind speed limit for the specific crane in the lift plan before starting.
Assess the sail area of every load and set lower wind limits for large flat items.
Stop lifting operations when wind speed approaches the limit — do not wait until it exceeds.
Account for height amplification when using ground-level anemometer readings.
Use the lift plan to define specific wind limits for each load and lift configuration.
Assign the decision to stop lifting to the appointed person or lift supervisor.
Monitor for gusting conditions — peak gusts can far exceed the average wind speed.
Secure any suspended loads before leaving them unattended as wind increases.
Brief the crane operator and rigging team on the wind limits at the start of each shift.

DON'T lift when wind speed at the working height exceeds the crane's rated limit.
DON'T assume the crane limit applies to all loads — large flat items need lower limits.
DON'T rely on ground-level wind readings alone — wind is stronger at the boom height.
DON'T continue lifting as conditions deteriorate — stop before the limit is reached.
DON'T ignore gusting — a sudden gust can exceed the average speed by 50% or more.
DON'T lift without a wind speed limit specified in the lift plan for each load.
DON'T override the appointed person's decision to stop lifting due to wind.
DON'T leave a load suspended on the crane when wind conditions are worsening.
DON'T resume lifting until wind conditions have been below the limit for sustained period.
DON'T skip the wind limit briefing — the operator must know the limit before any lift.

See also: Lifting Operations Awareness (LOLER) | Exclusion Zones During Lifting

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