Monday, October 04, 2004

F4 Phantom Jet Hits Concrete Wall at 500 MPH

How do you test whether the concrete wall you have built is capable of surviving a jet fly into it?

Erm... you fly a jet into it. At 500mph. And it looks like this. Woo fscking yay!

via b3ta - first chance I've had to look at the newsletter due to kicking Gaulish arse all weekend so there maywill be more linkage from this before the end of the day.

2 comments:

Merg said...

I've seen this on TV -- I think it was part of the late, lamented (if only for the "balls") Tomorrow's World.

Mike Goad said...

That’s an old video. I think it was actually transferred from film. It’s been at least 20 years since I first saw that.

The concrete block is actually reinforced concrete. The reinforcing rods are a lot thicker than standard rebar and they are very, very close together. The concrete itself has specific strength standards as well.

The test was not intended to demonstrate that the concrete could withstand an attack. It was one of a series of tests to see of the concrete used in reactor containment structures could withstand airborne missiles of all kinds – and in this context, missile does not mean weapon. It is just something that – due to an accident or a force of nature – is thrown with great force into the containment building.

One item that was in the same film was a segment of a steam turbine blading that was strapped to a rocket sled. When the rocket sled reached the end of its track, it was stopped by some mechanism, but the turbine blading continued on and smashed into the side of the reinforced concrete block.

Also, if you’ll look at the video, the jet is on a rocket sled and the jet’s engines are not what is pushing it – the rocket on the rocket sled is.

This film segment also didn’t show the damage to the concrete block, which, as I recall, was in the original film. There was damage in both instances, though not significant enough to breach the liner plate on the opposite side, and I think that the turbine blading actually caused more damage than the jet did. Steam turbines rotate at 1800 rpm and the tips of the blade are moving very fast with very close tolerances. If something happens where the blading comes in contact with other parts of the turbine, the turbine rotor could fly apart and the pieces would then be missiles.

We used to use the video in some our class, but I hadn’t seen it in a long, long time.