
1-10
If the wind is in excess of 45Km/h, do not perform any movements liable to endanger the lifting platform’s
stability.
- To recognise this speed by eye, please refer to the empirical wind evaluation scale below:
BEAUFORT scale (wind speed at a height of 10m over flat terrain)
Degree Type of wind Speed
(knots)
Speed
(km/h)
Speed
(m/s) Ground effects Sea conditions
0 Calm
0 - 1 0 - 1 < 0,3
Smoke rises vertically. The sea is like a mirror.
1Very light
breeze
1 - 3 1 - 5 0,3 - 1,5
The smoke drift indicates the wind
direction. Some wavelets, like fish scales,
but no foam.
2Light
breeze
4 - 6 6 - 11 1,6 - 3,3
Wind felt on exposed skin, leaves
rustle. Small but noticeable wavelets.
3Gentle
breeze
7 - 10 12 - 19 3,4 - 5,4
Leaves and small twigs constantly
moving. Very small waves, crests
beginning to break.
4Moderate
breeze
11 - 16 20 - 28 5,5 - 7,9
The wind raises dust and scraps of
paper, it moves small branches. Small waves with breaking crests,
frequent white horses.
5Fresh
breeze
17 - 21 29 - 38 8 - 10,7
Small trees in leaf start to sway. Wavelets form on stretches of
water, moderate waves of some
length.
6Strong
breeze
22 - 27 39 - 49 10,8 - 13,8
Large branches are moved,
overhead wires whistle, umbrella
use becomes difficult.
Waves form with white foam
crests and airborne spray.
7 High wind
28 - 33 50 - 61 13,9 - 17,1
Whole trees are moving, effort
required to walk against the wind. The sea heaps up; some foam
from breaking waves is blown into
streaks in the wind direction.
8 Gale
34 - 40 62 - 74 17,2 - 20,7
The wind breaks off twigs, walking
against the wind is very difficult.
Moderate height longer waves
with breaking crests forming
spindrift.
9 Strong gale
41 - 47 75 - 88 20,8 - 24,4
The wind damages roofs
(chimneys, tiles, etc.).
Large waves, dense spindrift
wrenched from the waves,
airborne spray reducing visibility.
10 Storm
48 - 55 89 - 102 24,5 - 28,4
Rarely seen on land, trees
uprooted, dwellings incur
significant damage.
Very large waves, foam forming
large amounts of airborne spray,
reducing visibility.
11 Violent
storm
56 - 63 103 - 117 28,5 - 32,6
Very rare, extensive damage. Waves of exceptional height
capable of sinking medium-sized
ships, reduced visibility.
12 Hurricane
64 + 118 + 32,7 +
Disastrous damage. Sea completely white, air full
of spray and foam, severely
reduced visibility.
547408 EN (15/05/2012)