Weight versus wind-loaded area is the problem. The lack of side radius allows no relief.
From a discussion on RV.net about towing in high winds, the following is a formula from the State of Wyoming Department of Public Safety in re wind loads.
Evaluation of Intelligent Transportation System Alternatives for
Reducing the Risks of Truck Rollover Crashes Due to High Winds FHWA-WY-07/01F
If you want to calculate an estimate of how much wind speed is required to overturn your trailer, you can use
V = SQRT(W*b/{0.00666*l*(h-h2/2)*(h/2+h2/4)})
where
V = wind speed, mph
W = trailer weight, lbs
b = trailer width (tire center-center), ft
l = trailer length, ft
h = trailer height (from ground), ft
h2 = tire height, ft
For example, with W=8000#, b=8', l=30',h=10',h2=3' -- the calculated overturning wind speed is 81 mph.
As expected, the most sensitive factor is trailer height. If the height is increased to 12', the overturning wind speed reduces to 67 mph.
These calculations are for square box trailers.
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