Twisters

[jx2mad]

Tragic loss of life in the U.S.A. but correct me if I am wrong. Looking at all the debris it seems to me that most houses are timber. Why would they not build solid structures in Brick etc seeing they live in a storm ridden area and why did they not all have storm cellars? Cost? I have a friend in north Qld who has cables running over the roof of his house and anchored into huge concrete blocks, back and front, These cables can be tensioned as the need arises. Jim

[JDNSW]

Cost. Most houses in the USA are made of timber - timber is a lot cheaper than it is here. It is not, however clear why there were few storm cellars - these are the traditional tornado precaution in that area. I assume that because there was no law requiring them, they were omitted, simply to reduce the cost of the houses.

I doubt either use of masonry or steel cables would have helped - only reinforced concrete and special design would be proof against major tornadoes. These are far more destructive than cyclones, albeit over a much smaller area. Typical wind velocities would be about twice as high as in a cyclone, and bear in mind that wind load is proportional to the square of the wind velocity. In this case the figure of 300mph has been quoted, compared to a typical cyclone of perhaps 150kph.

John

[PhilipA]

A severe tropical cyclone will be classified as a category five severe tropical cyclone should the cyclone's maximum sustained wind speed be greater than 110 knots (200 km/h, 130 mph) and gusts be above 150 knots (280 km/h, 175 mph).[17] (https://en.wikipedia.org/wiki/Tropical_cyclone_scales#cite_note-BOM_FAQ-17) Wikipaedia

I had to build my garage to Cat 5 on Magnetic Island, and I believe it would have had a good chance of survival . It cost me $11000 to have built.

So it looks to me that the USA authorities are really lax, especially regarding public buildings like schools.
Regards Philip A

[jx2mad]

Still it is a tragic situation with lives lost and so much destruction. Maybe they were just unfortunate that it didn't miss.

[Tusker]

That was my impression when travelling through a few years ago. The housing was very lightly built by our standards, let alone. Let alone introducing Darwin style cyclone standards.

I'm not inn the building game, but to the uneducated eye, new construction just looked flimsy.

Regards
Max P

[bee utey]

Apparently the soil in those parts is flat reactive soggy clay and a real pain to put a cellar in. Try keeping what's basically a well free from water and trash for 20+ years until it blows.

Retrofiiting a storm cellar would cost more than many home owners would be willing to pay. After all, the vast majority of USA houses don't get blown down in a given decade. The replacement houses will be timber too because they flex better with the seasons soil wetting cycles.