Wind speed can unfavorably influence aerial work platform lifting activities. It should be thoroughly considered while working at height, whatever the type of machine. The operator must ensure that the equipment is not exposed to any wind exceeding the limits set by the manufacturer. Indeed, operation in wind speeds above this maximum may cause instability.
Wind rating requirements
Because wind and occurring gusts of wind are factors of accidents, outdoor MEWPs are subjected to imposed wind speed limitations. Today’s ISO standards specifically address wind ratings on mobile elevating work platforms: the maximum limit of wind speed in which a MEWP can work is 12.5 m/s (28 mph). Haulotte outdoor-rated machines are designed and manufactured for use in wind as limited by the ISO standards.
The maximum permissible wind speed is specified in the Operator’s Manual supplied with the machine and should be marked on the serial plate. We strongly recommend operators to have a look at the recommendations before using the aerial work platform.
Measuring wind speed
It is crucial to analyze the wind conditions before operating an aerial lift. We strongly advise to:
- check the weather forecast daily;
- identify potential areas where wind gusts can be locally high prior to beginning work;
- use an anemometer to determine how strong the wind speed is.
Anemometers are a reliable and accurate handheld device to measure wind speed. They exist in digital and analog versions and come in all shapes and sizes. Make sure there is one available to measure wind speeds on site at the height of platform operations (it is worth noting that wind speeds increase with height and may be 50% greater at a height of 20 meters above ground level). Do not hesitate to take hourly measurement and don’t forget additional batteries!
What are the potential risks?
Operating MEWPs in windy conditions can lead to a dangerous situation. One of the identified hazards is machine tip-over.
Care must be taken when handling panels or large materials as they can increase the area exposed to the wind and seriously affect the stability of the MEWP, especially in gusty wind conditions. It should also be noted that Mobile elevating work platforms are not designed to hold banners. They can make the MEWP unstable which could cause an overturn.
To learn more about the “sail board” effect, read this IPAF article :
Beware of gaps between buildings! Operating an aerial work platform between buildings during windy weather is hazardous. The “wind tunnel” effect increases the speed and intensity of the wind and can destabilize the equipment.
Any doubt? Postpone the job!
Do not underestimate the potential danger of lifting operation in strong or gusty winds. When wind speeds exceed 12,5 m/s or 28 mph, lower the machine and do not continue to operate the machine until the wind falls below that speed.