Grain elevator vs tornado

[Justin McGinley]

Ok I am working at one of our local grain elevators for a agriculture giant. Well since i am in nebraska we get tornadoes alot. So because of that our tornado shelters are the office basement (no longer there since its been move to new facility), the rock or the very old white cement elevator basement, or leg boot pits. So my question is how munch of a blow could this elevator take when it is full, empty? It is reinforce concrete and the bins are 8 inches thick. From hearing from the people there working for a long time it sounded like it was also the town bomb shelter years and years ago also.

 

[David C Watson]

Well, I'm no expert but evidence of the ground being scoured, asphalt from the highway and roads stripped is winds of at least 250+ mph probably closer to what I would say 300 mph. With that being said it would definitely take those wind speeds to completely destroy the grain elevator. So it would most definitely take an upper end EF-5 tornado to do serious damage to one. For Example, in Bridge Creek, OK during the May 3rd, 1999 tornado, (which was an F-5 on the previous scale with 301 mph winds measured at ~32m above the surface) would have likely destroyed a grain elevator with ease. Those wind speeds will do that damage.

 

[Wes Carter]

FWIW, May 4, 2007 EF5 in Greensburg, Kansas damage photo:

 

[Justin McGinley]

Well wes thanks for the pic like they say a picture is worth a thousands words!

 

[David C Watson]

The Greensburg tornado wasn't as strong as the Bridge Creek/Moore, OK tornado so we might not know for quite a while what might actually will happen if a tornado the caliber of May 3rd hit a grain elevator..

 

[David C Watson]

Plus, if you also notice in the picture that area where the grain elevator was standing was also surrounded by other buildings nearby that didn't receive as devastating damage as the rest of the town, so that means that particular area didn't take a direct hit from the tornado itself.

 

[Scott Weberpal]

I think it would be nearly impossible for a tornado of any strength to topple a concrete grain elevator. They are probably safer than rebar reinforced concrete safe rooms.

 

[David C Watson]

Well we really won't know till that day occurs when something like that takes a "direct" hit from an EF-5 with winds in excess of 300+ mph.

 

[Mike Smith]

The Greensburg tornado wasn't as strong as the Bridge Creek/Moore, OK tornado

We don't know that to be true. BC/M had a Dow close enough to get the 300+mph wind speed. There was no comparable measurement of the Greensburg tornado. The WSR-88D tornadic signature on the Trousdale tornado (northeast of Greensburg, same supercell) was clearly stronger than BC/M if that somewhat apples-to-apples comparison is meaningful.

Mike

 

[Matt Tottle]

One thing that hasn't been taken into account is the age of the elevator. Most of the concrete tube elevators are 40+ years old and were built by the same company. With the natural aging and deterioration of concrete (and the high environmental stress it receives in this area from temperature swings and wind), I would not count on one to survive a direct hit. Last June one of our elevators had two (less than half full) bins collapse and kill two people on a bright sunny day. The investigation showed the concrete had deteriorated internally even though there were no visible signs. The rest of the bins were torn down and will be replaced with metal ones. My opinion? I would seek shelter AWAY from the bins, because in the event they do collapse, you don't to be trapped in your shelter buried under millions of tons of grain.

 

[Justin McGinley]

Matt thats a good point i never thought of that.