RUTHMANN 27409, Operating And Maintenance Instructions Manual

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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/m
²
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.