Wind and weather at crane lifting

Weather can make an otherwise well-planned lift dangerous. Wind, poor visibility, cold and ice affect both the crane, the load and the person working. Therefore, an assessment of weather conditions is a fixed part of planning when lifting outdoors.

§Why wind is a main hazard

The wind grabs at the load and the crane's boom and can set the load in motion so it begins to swing or rotate. With high lifts and long booms the crane becomes more sensitive to wind forces. A load that suddenly catches the wind can become difficult or impossible to control and it can in the worst case affect the crane's stability.

§Load windage

It is not only the wind's strength that determines the danger, but also the shape of the load. A large, flat load — such as a plate, an element or a light, voluminous object — catches much more wind than a compact, heavy load with a small surface. Two loads of the same weight can therefore behave very differently in the wind.

§Controlling the load in wind

Pendulation and rotation can be dampened with a guide line so you can hold the load at rest from the ground without standing under it. But a guide line has its limits: if the wind takes too much hold, the load cannot be safely controlled anymore, and so the lift is postponed until the wind subsides.

§Sieve, cold and ice

Poor visibility — fog, heavy rain, snow, or darkness — makes it difficult for the driver and signaler to see the load and area and communication becomes uncertain. Cold and ice can make the surface slippery, freeze mechanics, and make tools and surfaces slippery to handle. All these factors are included in the assessment of whether the lift is safe.

§The decision to postpone

When weather makes the lift uncertain, it's postponed. That's a professional decision, not a defeat: a lift can always be done later when conditions are better. Doubt about wind counts the same as doubt about weight or stability—if there's doubt, there's no lift.