User guide

45 Mbps Backhaul User Guide
Issue 3, December 2004 Page 92 of 113
10 Wind Loading
10.1 General
Antennas and electronic equipment mounted on towers or pole mounted on buildings will subject the mounting
structure to lateral forces when there is appreciable wind. Antennas are normally specified by the amount of
force (in pounds) for specific wind strengths.
The magnitude of the force depends on both the wind strength and size of the antenna.
10.2 Calculation of Lateral Force
The 45 Mbps Backhaul unit with or without the integral antenna is essentially a flat structure and so the
magnitude of the lateral force can be estimated from:
Force (in pounds) = 0.0042 . A . v
2
Where A is the surface area in square feet and v is the wind speed in miles per hour.
The lateral force produced by a single 45 Mbps Backhaul Unit at different wind speeds is shown below:
80 100 120 140 150
45 Mbps Backhaul
with integrated
antenna
1.36 37 57 82 112 129
Connectorized 45
Mbps Backhaul
1.00 27 42 60 82 95
Item
Largest
Surface
Area (sq ft)
Lateral Force (Pound) at windspeed
(mph)
The equivalent table in metric units is:
30 40 50 60 70
45 Mbps Backhaul
with integrated
antenna
0.1300 12 22 34 49 66
Connectorized 45
Mbps Backhaul
0.0930 9 16 24 35 48
Item
Largest
Surface
Area (sq m)
Lateral Force (kg) at windspeed (m/s)