RUTHMANN Steiger TB270 - Beaufort-Scale

2 Technical Specifications
BA.GB.12-27409-05-07-FTA-jr
RUTHMANN-Steiger
®
TB270
2-11
2.4 Beaufort-Scale
Extract of the Beaufort-Scale
Wind
force
Wind
speed
Effect of
the wind in
Impact
pressure
Degree
1
Description
m/s
km/h
interior
N/m²
5
fresh
breeze
8,0 - 10,7
29 - 38
Small deciduous trees
begin to sway, white crest
in lakes.
40 - 72
6
strong
breeze
10,8 - 13,8
39 - 49
Strong branches in mo-
tion, whistling noise in
telegraph poles, umbrel-
las can hardly be hold.
73 - 119
7
stiff breeze
13,9 - 17,1
50 -61
Complete trees in motion,
strong resistance when
walking against the wind
120 - 183
1
Beaufort-degree
Beaufort-Scale according to the British Admiral and Hydrograph Sir Fran-
cis Beaufort (1774 - 1852) for estimating the wind force according to the
observed effects.
The indications of the above table refer to an internationally determined
measuring height of 10 m above ground on open terrain. With similar
Beaufort degrees you have to calculate with wind speeds increased by
20% at a measuring height of 30 m above ground.
For operation of the Ruthmann-Steiger the permissible wind speed of
12,5 m/s must not be exceeded. According to the Beaufort-Scale this
means a wind force of 6-Beaufort-degree. Exceeding this the operation
must be stopped. You have to observe that with increasing working height
also the wind speed gets higher.