Crash Video Benchmark

[abababba]

I just noticed this video online

http://www.youtube.com/watch?v=RKiufIpP7_I&feature=related

It provides a benchmark of a plane at 500 MPH traveling into a concrete structure. Why would an aluminum plane flying into the steel WTC go so much further after impact?

[stannrodd]

Just a couple of things.

This demonstration was done as a test to determine the strength of a specialized concrete formula used in nuclear power plants to protect them from an attack. No doubt other military applications of the concrete for bunkers etc were being assessed.

It isn't a test to determine what happens to an airliner when it impacts a skyscraper made of steel columns and mostly thin air. (or Pentagon)

It is commonly posted to "show" that planes could not have penetrated the WTC towers.

I don't see it as a crash video "benchmark" as such .. but it does show what happens to the F4 Phantom twin jet fighter .. it atomizes as expected,

.. given the dynamics of the collision it was always going to be a success for the concrete.

Stann:)

[abababba]

Just a couple of things.

This demonstration was done as a test to determine the strength of a specialized concrete formula used in nuclear power plants to protect them from an attack. No doubt other military applications of the concrete for bunkers etc were being assessed.



Thanks for the reply. Are they able to make this reinforced concrete harder to break through than steel?

I definitely understand your point about the thickness of the material being important, but the plane doesn't seem to penetrate very far into the concrete.

I don't know if I can make the jump from an almost complete deceleration on impact in this case to very little if any deceleration in the WTC, but maybe you are right that this isn't the best example.

If anyone else has other head on crashes in other scenarios, it would be great to see them for comparison.

[stannrodd]

Thanks for the reply. Are they able to make this reinforced concrete harder to break through than steel?

I definitely understand your point about the thickness of the material being important, but the plane doesn't seem to penetrate very far into the concrete.

I don't know if I can make the jump from an almost complete deceleration on impact in this case to very little if any deceleration in the WTC, but maybe you are right that this isn't the best example.

If anyone else has other head on crashes in other scenarios, it would be great to see them for comparison.

There is no known footage of the El Al 747 cargo plane which impacted into an apartment block in Amsterdam (October 1992), but the post impact devastation was well documented, including the pollution by radioactive depleted uranium counterweights.

You could look into that. There wasn't much left of the plane or the building.

Images and story here ..

http://en.wikipedia.org/wiki/El_Al_Flight_1862

Stann

[secondsun]

.....reinforced concrete harder to break through than steel?


...a comparison of fragility!


...solid concrete looks like this!

http://amazingtextures.com/textures/data/media/8/CONCRETE_014.jpg


....does this look like solid steel???

http://www.alice-dsl.net/periodsoflife/images/11.%20September/7571897_large.jpg

[stannrodd]

Secondsun,

I love that photo of the towers .. it really shows how much empty space there was.

Solid concrete block v fighter jet is a very different thing to .. WTC Tower v 767 variant or real... or not real !!

!00tonnes of metal + compressed anything else .. @ 500mph = hole in tower

Stann

[tannah]

Secondsun,

I love that photo of the towers .. it really shows how much empty space there was.



Yeah, almost makes you wonder where all that weight could have come from to send the whole thing pancaking down doesn't it? Looks like it shouldda floated into the air.

[bryan]

Yeah, almost makes you wonder where all that weight could have come from to send the whole thing pancaking down doesn't it? Looks like it shouldda floated into the air.

It wasn't just weight. It was . . . KINETIC ENERGY!

[mercuryrapids]

The huge concrete block didn't have windows, glass etc. It's a strawman comparison...

[stannrodd]

Yeah, almost makes you wonder where all that weight could have come from to send the whole thing pancaking down doesn't it? Looks like it shouldda floated into the air.

" ..... it shouldda floated into the air ... "

Just like skyscrapers should .. but don't .. :confused:

Amazingly Vogon Constructor fleets do .. :D

Yeah I still don't see a CCC ..

Stann

[secondsun]

The huge concrete block didn't have windows, glass etc. It's a strawman comparison...

...but if a `huge concrete block` had `windows, glass etc`.... would it still be a `huge concrete block`?.... why not try a logic comparison some day!?

[stannrodd]

...but if a `huge concrete block` had `windows, glass etc`.... would it still be a `huge concrete block`?

?? of course complete with windows etc .. ??

Almost thin air .. versus "Totally" concrete block ..

"scratches head" ..

Stann

[bryan]

I love that photo of the towers .. it really shows how much empty space there was.



Almost thin air .. versus "Totally" concrete block ..


How much potential energy is there in 'empty space' or 'almost thin air'?

A fall of 12ft has to convert that potential energy into enough kinetic energy to fracture 47 steel core columns six times a second for sixteen seconds, throw steel perimeter sections hundreds of feet and pulverise all the concrete. And that's a conservative estimate.