The Beaufort Scale of Wind Force is accepted internationally and is used in communicating weather conditions. It consists of number 0 – 17, each representing a certain strength or velocity of wind at 10m (33ft) above ground or in the open. This should be used to assess when it is safe to operate your powered access equipment.
Description of wind |
Specification for use on land |
MPH |
0 Calm |
Calm, smokes rises vertically |
1 |
1 Light Air |
Direction of wind shown by smoke drift but not by wind vanes |
1 - 3 |
2 Light Breeze |
Wind felt on face; leaves rustle; ordinary vanes moved by wind |
4 - 7 |
3 Gentle Breeze |
Leaves and small twigs in constant motion; wind extends light flag |
8 - 12 |
4 Moderate Breeze |
Raises dust and loose paper; small branches are moved |
13 - 18 |
5 Fresh Breeze |
Small trees in leaf begin to sway; crested wavelets form on inland waters
MOST POWERED ACCESS PLATFORM & BOOM WORK WILL CEASE UNDER THESE WIND SPEEDS |
19 - 24 |
6 Strong Breeze |
Large branches in motion; umbrellas used with difficulty |
25 - 31 |
7 Near Gale |
Whole trees in motion; inconvenience felt when walking against wind |
32 - 38 |
8 Gale |
Breaks twigs off trees; generally impedes progress |
39 - 46 |
9 Strong Gale |
Slight structural damage occurs (chimney pots and slates removed) |
47 - 54 |
Note: Approximate corrections for wind speeds at other heights are:
