In what wind speed can a machine work?
All MEWPs (except those designed specifically for indoor use) are designed to operate in wind speeds up to a maximum which should be marked on the machine. Operation in wind speeds above this maximum may cause instability. The generally accepted design wind speed, and also the maximum in which an operator can work comfortably, is 12.5 m/s (28 mph). Wind speed can be measured from the platform with a hand held anemometer but it is more usual to estimate using the Beaufort Scale of Wind Force (see below). It is very important to realise that wind speed increases with height and may be 50% greater at a height of 20 metres above ground level. Wind chill factor. On a calm day 10 degrees Centigrade is cool but not unpleasant. But with a wind of 20 mph, the temperature experienced on the face and hands is 0 degrees Centigrade, and at freezing, the temperature is -15 degrees Centigrade. This makes it very important to wear warm clothing even though it might feel relatively warm at ground level
