Wind Load for ISO Shipping Container

here are some general wind load ratings for shipping containers.

F = A x P x Cd

F = Force
A = Area
P = Wind Pressure
Cd = Coefficient of Drag (for a flat surface such as a container it would be 0.6)

These numbers are not to be used for exact calculations, as container specifications vary somewhat between manufacturers and shipping lines. As I stated before, if you need exact calculations you'll want to find a qualified engineer familiar with your area to certify that your container structure is safe.

https://containerauction.com/read-news/shipping-container-wind-rating-and-load-capacity

Thanks Solar Eagle , I have seen this chart earlier , but I didn't understand why the weight of the containers were not factored in the equation F = A x P x Cd . My goal is to get a reasonable idea of the mph it would take to tip over a container with cargo inside , say 5000 lbs . Seems to me , the heavier the container , the more force it would take to roll it over. I have numerous containers that have been on the farm for a lot of years, without incident , now the building dept wants me to anchor them to ground . They don't required containers under 20 ft to be anchored . Would like equation to present to building dept with a loaded and unloaded container . I need to keep containers mobile Thanks

Pretty sure they will want figures representing empty containers = minimum weight....unless maybe the containers are sealed and the weight is never altered, and that can somehow be certified/guaranteed, then you might find a way ...In other words you can't load up a container to meet wind load max and then reduce the weight by unloading some of the stuff.... Now whether they would let you build berms to reduce wind load, I don't know...maybe concrete walls as windbreaks...In any case it gets involved....It would be easier to just anchor them to the ground with removable stainless steel cables...how hard is it to just unhook a connection...?...of course depending how many I had....maybe just position them side by side and berms on either end...?

http://www.vantagefreight.com.au/wp-content/uploads/2013/01/Container-Dimensions.pdf

http://www.residentialshippingcontainerprimer.com/ISO%20Shipping%20Containers%20and%20Building%20Code%20Requirements%20

Weight doesn't come into F = A x P x Cd because that is the calculation of force at a given wind speed (P is a function of wind speed).

This is then equated to the force needed to overturn, which includes weight of container and contents (if "they" allow inclusion of contents). Solve that for P hence wind velocity.

If contents are allowed, the effect varies with how they are placed, not just on total weight.

Thanks again

If you use a solid concrete wall you will have a couple of problems: 1. Behind and below the wall you will have high turbulence and at the top of the wall you will have increased wind speed.

If you use a vented wall, like a fence with horizontal slats, you will eliminate the turbulence and the air speed over the top of the wall will be reduced.

This is a simple explanation, the calculation comes with determining the height of the wall and how far it is from the stationary object.

I believe the reply with the rated wind speeds is actually referring to the structural wind rating of a container, before damage or destruction to the container itself occurs. That's why there is no load component (weight of cargo) to the equation. The building dept. will want to know this wind rating, as well as when the container (loaded or unloaded) will begin to move from its location, either by sliding or turning over. Your worst case instance will be a wind force perpendicular to the long side of the container. Without knowing the coefficient of friction between the container and the surface it is resting on, and the center of gravity, I am unable to provide you with a detailed response.

I agree with your statement you have never had one move on you. I have one here in the mtns. of Colorado for 11+ years, with the highest recorded wind gust of 102mph, and it didn't move. It is just sitting on the ground, no anchoring of any kind.

See here:

http://adaptivemap.ma.psu.edu/websites/friction/slipping_vs_tipping/slippingvstipping.html

I like that, even if a tad over-simplified. IMHO, if the said box profile begins to tip, there is now wind pressure under the floor of the object, and this will accelerate tipping. Like I said, IMHO.

Obviously, the equations seem to be plenty valid up to the point of tipping.

Obvious thought: A box with 2" layer of lead on the floor is harder to tip over than a box with a 2" layer of lead on the leeward wall, the windward wall, or the ceiling.

Mass distribution has to play a role in the calculation, unless we are talking a lightweight floor, and basically empty Conex containers.

And that's why I added "center of gravity" to the discussion. Or, if you are more familiar with "center of mass", use that instead. With uniform gravity, they are the same.

Yep, no argument there at all.

I agree with your comment to a degree, but im just a simple guy :)

In this instance, I believe overcomplicating things (as seems to be the fashion on this forum), does not add any value to the OP. If concerned, a higher factor of saftey could be added to the equation than is normal.

Also, if the OP needs things to be legally binding, they will still require certification/sign-off from a qualified professional for submission to their local authority anyhow.

Cheers