How to judge site safety in windy conditions

How to judge site safety in windy conditions

When operating a cherry picker or other types of access machinery at height, there are numerous weather conditions that can make operating safely difficult. At this time of year, winds and low temperatures can limit when and where you can use your cherry picker. Of course, in cases of severe weather, this type of machinery should not be used at all. But at what point do you deem wind and temperature to be too severe to operate? This blog covers some essential tips when it comes to operating in winds.

Strong winds

Most outdoor cherry pickers are built to be able to withstand wind speeds of up to 28 miles per hour – or 12.5 m/s – so should not be used when the speed exceeds this. Various specialist cherry pickers are designed to withstand even stronger winds but, unless marked otherwise, 28mph is the general capability. Of course, if you are hiring an indoor cherry picker, these machines are not designed to be wind speed rated at all, so should not be used outdoors in any weather. The best way to check the wind speed capability of your specific machine is to consult the operating manual or call the Rapid Platforms team for advice.

Gaps and inclines

On days where wind speed is high, you should not use cherry pickers in between gaps in buildings. This is because buildings can create wind tunnels, essentially funnelling the wind through the gap and thus concentrating its force to reach turbulent levels. Sudden strong gusts of wind through these types of funnels increases the likelihood of instability. Even in lower winds, you should always devote extra care and consideration to areas between buildings. Inclines can also add to the impact of winds; if you are operating on an incline, wind forces blowing in the same direction as the incline will increase the likelihood of instability. Generally, low inclines are fine for positioning your cherry picker; just be aware that this incline will offer a greater degree of risk if conditions are blustery.

Wind chill

It is not just stability of the cherry picker that is a consideration in windy conditions. There is also the issue of wind chill factor and a full risk assessment should be carried out before any staff are elevated to extreme heights. An outdoor ground temperature of ten degrees, for example, means fairly pleasant working conditions. However, at a height, and in winds of around 20 miles per hour, this temperature can feel more like zero degrees. Working even for short periods of time at this temperature can lead to visual impairment, lack of judgement, confusion, poor coordination and behavioural changes in your staff, so should be avoided.

Working at height

Wind speed is also faster at height. A ground wind speed of 28 miles per hour could be 50% greater at your cherry picker’s elevated level. At height on a cherry picker, you will be more exposed to the elements and wind speed and strength will feel a lot greater. To measure wind speed both on the ground or at height, you can use an anemometer – this is considered to be more reliable and easier to read than the Beaufort Scale and contains a higher degree of accuracy that is essential when deciding on whether or not it is safe to use your access machinery.

For further information or if in doubt, refer to the Health and Safety Executive’s guidelines for MEWPs and other access machinery before you attempt to use your cherry picker.