SAFETY
BG 25 / 2011 /
2254_BG25_en_0000498763_V01
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2.6
PERMISSIBLE WIND SPEED
The place to measure the wind speed is at the masthead:
Max. permissible wind speed for equipment operation
Barrier effect
m/s
km/h
miles/h
Beaufort
ktn
20
72
45
8
39
250 (N/m²)
WARNING!
Rig tipping hazard!
Shut down the equipment before the value is exceeded.
Remove attached drilling tool(s) and suspended load.
Lower movable components as close to the ground as possible.
Adjust the uppercarriage in line with the undercarriage and interlock them.
Set the mast into the minimum working range.
Extend the mast prop (if equipped) to the ground.
Table of wind forces and speeds
Wind force
Wind speed
Wind effects
Beaufort
English
m/s
km/h
0
calm
0 - 0.2
less than 1 Smoke rises straight in the air, sea is calm-glassy
1
light air
0.3 - 1.5
1 - 5
Smoke drifts but vanes remain still, sea is rippled
2
light breeze
1.6 - 3.3
6 - 11
Wind can be felt on your face, leaves rustle,
sea has wavelets
3
gentle breeze
3.4 - 5.4
12 - 19
Leaves and thin twigs move, pennants
stretch, wave crests begin to break
4
moderate breeze
5.5 - 7.9
20 - 28
Dust and paper lift, twigs and branch lets
sway, waves are growing in length, scattered
white-caps
5
fresh breeze
8 - 10.7
29 - 38
Small trees begin to sway, waves are white-
capped all over the sea
6
strong breeze
10.8 - 13.8
39 - 49
Sturdy branches move, wires sing, umbrellas
are hard to handle, sea is rough, crests break
7
near gale
13.9 - 17.1
50 - 61
Whole trees swaying, walking towards the
wind is difficult, sea is very rough, foam on
crests
8
gale
17.2 - 20.7
62 - 74
Branches break off, walking outdoor is extremely
difficult, waves are high, spray from crests
9
strong gale
20.8 - 24.4
75 - 88
Minor damage to buildings (roof tiles and
chimney hoods are ripped off), on the sea
waves are very high and the visibility is ob-
structed by spray
