Yeti wrote:
Jeff Lawrence wrote:
On Sep 9, 12:31 pm, Yeti wrote:

Almost nothing the US Government says about 9/11 adds up.

Maybe, maybe not, who can really say as there is no precedent to
compare it to. But what they say still makes a hell of a lot more
sense than some of the crackpot conspiracy theories that are out
there.
Cheers
Jeff


Granted - but here's the basics:

No steel framed building has EVER collapsed due to fire before 9/11, or
since. Yet we're expected to believe that at least THREE did that day.

No plane crash has ever left as little wreckage as any of these four
crashes that day.


WRONG - many plane crashes leave next to nothing, one a few years ago ,
a 737 had an in flight fire when emergency oxygen units being carried
caught fire. The crash from a vertical dive left a small crater and few
if any large pieces, no human remains bigger than a thumb.


from youtube

http://www.youtube.com/watch?v=RxLlY0ihku4


Something definately doesn't add up somewhere.

Only if you *want* to find something.

http://www.youtube.com/watch?v=gzFq3-HT91c

Re plane into concrete block...
It is possible the turbine shaft DID in fact penetrate.

Realise artillery barrels form the basis of deep ground penetrators
(then timed munition goes off after counting floor impacts).


Re track-cracking Class 86 loco into nuclear flask...
It was very strongly rumoured that critical bolts were loosened.
Thereby lengthening the impact impulse at expensive of absolute peak.

Realise that MIGHT actually make things worse because it could act
like a dead-blow hammer. In a dead blow hammer the absolute peak
impulse is quite low because the head is light, but then the still
travelling shot within the hammer head impacts the head to
significantly lengthen the impact impulse - instead of a typical short
duration impulse & elastic rebound.

Alternatively it MIGHT have helped prevent the flask fracturing - an
86 loco has a significantly stiff frame with a lot of mass.


As for trusting government, one recent blatant example.
MP expenses were leaked, thankfully, by an Ex-SAS officer.
Later on expenses were released with vast areas blacked out -
sufficient to prevent ANY expose of the real missappropriation of
funds.

Conspiracy, well it is a useful wrapper either way.
I believe in very few and even then little of the supposed "evidence".
The hiliarious UFO hoaxes with NSA & CIA members "on the board" was a
nice cover for anything-black and future Unmanned Flying Objects.
Unmanned-FO has long been the natural progression re removing a) hard-
to-replace pilots and b) hard to package-in-a-stealth-plane pilots
from the battlefield or surveillance. So 20yrs ago the concept of
"UFO" seemed a very purile cover, although one which people wanted to
believe so plausible.

I am still amused at the "intelligence" reports coming in from around
the world about Saddams chemical & nuclear capability, no doubt MI6
crowd on a comfortable expenses paid holiday with a fax machine. Yes
he HAD chemical mortars, but I doubt UPS would exactly ship one for
him "and after obtaining a signature, place parcel A inside tube
contained within parcel B". The Iraq war intelligence was the biggest
load of bull**** the world has ever known, with moronic PR-agency
search-n-replace throughout it. Spin doctors being the
scientbollockology pioneered in the USA and exported to the UK with
Blair, teflon **** himself. Unlike Gordon who is likely to cause more
economic damage than Maynard Keynes could have ever dreamt up.

"Spike" wrote in message
...

Jeff Lawrence wrote:

On Sep 9, 12:31 pm, Yeti wrote:

Almost nothing the US Government says about 9/11 adds up.

Maybe, maybe not, who can really say as there is no precedent to
compare it to. But what they say still makes a hell of a lot more
sense than some of the crackpot conspiracy theories that are out
there.
Cheers
Jeff

It is now widely accepted that the attack on Pearl Harbour was
engineered by the Americans, by placing the Japanese in a position
with only one outcome, and ensuring the non-discovery of the progress
of their attack fleet by the 'vacant seas'order, which ordered all US
and allied shipping out of those waters.

IIRC a message saying something like "An attack may be expected at
about 8am your time" sat in the Commanader's in tray, which he fiddled
about with for an hour until the attack started.
from
Aero Spike


One of probably dozens of alerts that had previously come to nothing.
Avoidable disasters happen because of incompetence and information overload

I was in NY days before 9/11 and I'd never seen such an open city, in none
of the great buildings i visited was i once asked to open my shoulder bag
or searched, at the time i thought to myself what a soft target the city was

When i few from LaGuardia to Atlanta (for $25) i could have paid by cash
and called myself Saddam Hussein.
Like during Pearl Harbour the US was on a complacent peace footing.

Steve Terry

"Yeti" wrote in message
...
Jeff Lawrence wrote:
On Sep 9, 12:31 pm, Yeti wrote:

Almost nothing the US Government says about 9/11 adds up.

Maybe, maybe not, who can really say as there is no precedent to
compare it to. But what they say still makes a hell of a lot more
sense than some of the crackpot conspiracy theories that are out
there.
Cheers
Jeff

Granted - but here's the basics:

No steel framed building has EVER collapsed due to fire before 9/11, or
since. Yet we're expected to believe that at least THREE did that day.


No steel framed building fire has ever been fuelled by thousands of gallons
of aviation kerosene before.
Nor are most steel framed buildings so full of flammable material such
as thousands of tones of paper, furniture and fittings to soak up that
kerosene

Steve Terry

On 9 Sep, 22:10, "Steve Terry" wrote:

No steel framed building has EVER collapsed due to fire before 9/11, or
since. Yet we're expected to believe that at least THREE did that day.

No steel framed building fire has ever been fuelled by thousands of gallons
of aviation kerosene before.

I don't doubt that the impact and fires would have caused the collapse
of the towers but there is one bit that I have never understood.

I would have anticipated that the supports on one side of the building
would have failed, causing the tower to twist and fall sideways. Maybe
one side would collapse dragging the other side towards it. I would
never had anticipated that a building would pancake straight down into
it's own footprint, as all 3 did.

A sideways collapse was probably intended, the aircraft flew into the
towers from north and south.

Fred DIbnah used to fell mill chimneys like this; he'd gradually cut
out the brickwork on one side, inserting temporary timber supports.
He'd then burn out the timber supports and the chimney would fall like
a tree. Why didn't the twin towers fall like that, if the supports had
been asymmetrically damaged and burnt?

If you wanted to get a building to collapse straight down, I would
have thought that you would need to sever all the vertical supporting
columns simultaneously to achieve that. I'd think you could only
achieve that with a controlled explosive demolition. I admit that I
have no expertise in these matters.

There was a link posted on here some months back of the collapse of
WT7, which showed a line of simultaneous puffs of black smoke, all at
the same level, at the start of the collapse. I thought it looked very
like an explosive demolition. What was it? Had someone photoshopped
the video?

"Steve Terry" wrote in message
...

I was in NY days before 9/11 and I'd never seen such an open city, in none
of the great buildings i visited was i once asked to open my shoulder bag
or searched, at the time i thought to myself what a soft target the city
was

When i few from LaGuardia to Atlanta (for $25) i could have paid by cash
and called myself Saddam Hussein.
Like during Pearl Harbour the US was on a complacent peace footing.

Quite, I've seen people walk right up to the gates to meet people; folks
checking in guns, knives, hunting vests and ammo right on the tarmac on
internal flights to the states. I've also met a couple of academics from the
university that taught the Saudi boys how to take off. At the same
conference met a Saudi academic who was be moaning the fact that no young
Saudis wanted to go to university since daddy owned an oil well and all the
had to do was go to prayers and spend the rest of the day drifting. Foreign
infidels do all the work for them.

Hindsight is a glorious thing.

On Wed, 9 Sep 2009 14:29:17 -0700 (PDT), "
wrote:

On 9 Sep, 22:10, "Steve Terry" wrote:

No steel framed building has EVER collapsed due to fire before 9/11, or
since. Yet we're expected to believe that at least THREE did that day.

No steel framed building fire has ever been fuelled by thousands of gallons
of aviation kerosene before.

I don't doubt that the impact and fires would have caused the collapse
of the towers but there is one bit that I have never understood.

I would have anticipated that the supports on one side of the building
would have failed, causing the tower to twist and fall sideways. Maybe
one side would collapse dragging the other side towards it. I would
never had anticipated that a building would pancake straight down into
it's own footprint, as all 3 did.

A sideways collapse was probably intended, the aircraft flew into the
towers from north and south.

Fred DIbnah used to fell mill chimneys like this; he'd gradually cut
out the brickwork on one side, inserting temporary timber supports.
He'd then burn out the timber supports and the chimney would fall like
a tree. Why didn't the twin towers fall like that, if the supports had
been asymmetrically damaged and burnt?

If you wanted to get a building to collapse straight down, I would
have thought that you would need to sever all the vertical supporting
columns simultaneously to achieve that. I'd think you could only
achieve that with a controlled explosive demolition. I admit that I
have no expertise in these matters.

There was a link posted on here some months back of the collapse of
WT7, which showed a line of simultaneous puffs of black smoke, all at
the same level, at the start of the collapse. I thought it looked very
like an explosive demolition. What was it? Had someone photoshopped
the video?

I really don't see why people have difficulty with all this. It only
takes one floor to give way and the weight and force of the building
above collapsing onto the next floor causes the pancaking effect.

The air between those floors has to go somewhere, explaining the puffs
of air/black smoke out the sides as it falls.


This is worth a watch:
http://www.youtube.com/watch?v=bMZ-nkYr46w

On 9 Sep, 22:10, "Steve Terry" wrote:
"Yeti" wrote in message

...

Jeff Lawrence wrote:
On Sep 9, 12:31 pm, Yeti wrote:

Almost nothing the US Government says about 9/11 adds up.

Maybe, maybe not, who can really say as there is no precedent to
compare it to. But what they say still makes a hell of a lot more
sense than some of the crackpot conspiracy theories that are out
there.
Cheers
Jeff

Granted - but here's the basics:

No steel framed building has EVER collapsed due to fire before 9/11, or
since. Yet we're expected to believe that at least THREE did that day.

No steel framed building fire has ever been fuelled by thousands of gallons
of aviation kerosene before.
Nor are most steel framed buildings so full of flammable material such
as thousands of tones of paper, furniture and fittings to soak up that
kerosene

Steve Terry

That's if you accept the truth of the assertion.

One of the ironic thing about conspiracy theorists is their moronic
ability to accept all sorts of things as truths without any degree of
sceptical analysis or fact-checking, as long as they further the
hypothesis (as the hypothesis comes first, unlike in rational
thought).

On 9 Sep, 23:00, Theodore wrote:

I really don't see why people have difficulty with all this. It only
takes one floor to give way and the weight and force of the building
above collapsing onto the next floor causes the pancaking effect.


Yes, if the one floor goes straight down.
If one side of a floor collapses, the floor below will collapse at the
same side; the building falls sideways.

The question remains the same. How would you get one floor to go
straight down to initiate a straight-down collapse of the building? Is
it likely that would happen?

wrote:
On 9 Sep, 22:10, "Steve Terry" wrote:

No steel framed building has EVER collapsed due to fire before 9/11, or
since. Yet we're expected to believe that at least THREE did that day.
No steel framed building fire has ever been fuelled by thousands of gallons
of aviation kerosene before.

I don't doubt that the impact and fires would have caused the collapse
of the towers but there is one bit that I have never understood.

I would have anticipated that the supports on one side of the building
would have failed, causing the tower to twist and fall sideways. Maybe
one side would collapse dragging the other side towards it. I would
never had anticipated that a building would pancake straight down into
it's own footprint, as all 3 did.

A sideways collapse was probably intended, the aircraft flew into the
towers from north and south.

Fred DIbnah used to fell mill chimneys like this; he'd gradually cut
out the brickwork on one side, inserting temporary timber supports.
He'd then burn out the timber supports and the chimney would fall like
a tree. Why didn't the twin towers fall like that, if the supports had
been asymmetrically damaged and burnt?

because the fire was relatively symmetrical.

Progressive collapse is a well known phenomena. Once one floor fell and
knocked out the one below, it was 'goodnight Vienna' for the lot.

Dibnah ate away at the chimney BASE. this collapse started halfway up.
Essentially one vertical section collapsed, and the impact of the
storeys above was enough to wreck the lot.



If you wanted to get a building to collapse straight down, I would
have thought that you would need to sever all the vertical supporting
columns simultaneously to achieve that. I'd think you could only
achieve that with a controlled explosive demolition. I admit that I
have no expertise in these matters.

Indeed. You are half right, except what took out the 4 corners wasn't a
controlled explosion, it was the impact of the floor and the building
above falling on to it. Once any weakness started, the floor simply fell
out of the structure and went straight down. I cant remember the exact
details, but any slender column is liable to catastrophic buckling if
the lateral restraints are removed from the elements. Google Euler
instability etc.

What stops the vertical buckling is horizontal members connecting them:
those were essentially the floors IIRC. Once a floor unit went, nothing
held the columns in place, and they were already weak from the blaze.

Don't think 'tree' think 'tall pile of concrete and glass cards, tied
together by relatively weak steel ties' once those ties go, the thing
collapses like a house of cards.



There was a link posted on here some months back of the collapse of
WT7, which showed a line of simultaneous puffs of black smoke, all at
the same level, at the start of the collapse. I thought it looked very
like an explosive demolition. What was it? Had someone photoshopped
the video?


It was the first floor to go collapsing onto the one below,probably
blowing out the windows.
..

"js.b1" wrote in message
...

Plus of
course republican admin usually coincide with wars and democrat admin
usually coincide with deficit expansion.

In recent history, Democrat presidents have coincided with deficit
shrinking, and Republican ones with deficit expansion.

(The current banking fun'n'games makes it an interesting time for the
current one though)

wrote:
On 9 Sep, 23:00, Theodore wrote:

I really don't see why people have difficulty with all this. It only
takes one floor to give way and the weight and force of the building
above collapsing onto the next floor causes the pancaking effect.


Yes, if the one floor goes straight down.
If one side of a floor collapses, the floor below will collapse at the
same side; the building falls sideways.

No it doesn't.


You simply dont understand what a building is, engineering wise,
especially a tall steel and concrete one.

For it to fall sideways implies it retains enough structural integrity
as it falls to transit lateral loads to upper storeys to accelerate them
sideways. It cant do that if its effectively been sliced in half in the
middle.

Think of a pile of really heavy concrete biscuits, separated by cocktail
sticks. balanced one on top of the other. Now at a given layer start
removing coccktail stiicks. You cant push the lot over, because there is
simply no strength in bending: remember the ONLY lateral loads it was
designed for were high winds. Even an airliner ramming into it didnt
knock it over, because its so HEAVY. nothing is going to make it fall
sideways.




The question remains the same. How would you get one floor to go
straight down to initiate a straight-down collapse of the building? Is
it likely that would happen?

Its *guaranteed* to happen. If you lose structural integrity due to fire
at one level, affecting a large fraction of the 'cocktail' sticks,
sooner or later one, two three go, the floor sags, and at some point the
rest go more or less simultaneously - as one goes there is overload on
the next..you take out a complete layer of cocktail sticks..

Without a redundant, and much more expensive structure, progressive
collapse is almost 'designed in' to any large structure.

On Wed, 09 Sep 2009 15:47:34 +0100, Yeti wrote:

Mike Plowman wrote:
On Wed, 9 Sep 2009 07:28:01 -0700 (PDT), Jeff Lawrence
wrote:

On Sep 9, 3:11 pm, JohnB wrote:

... which may just be that too many people are trying to make 2 + 2
equal 5.
It's hard to take these conspiracists seriously when they keep coming
up with arguments like this one about the plane wreckage. Arguments
that have been easily been shown to be ridiculous time and time again.
Even now this Yeti is trying to make out that there were no parts
found outside the Pentagon when there are many photos disproving this,
which have been around since just after the incident happened. Or that
certain things shouldn't have happened the way they did when there is
no way of knowing exactly what should or shouldn't have happened
because such things have never happened before. The only way to know
for sure would be to build an exact replica of the towers, crash an
exact replica of the plane into them in exact the same way and see
what happens.
Cheers
Jeff

Sssh, Someone at the BBC might read that and comission a second
seriesw of The Big Bang Theory.

I hope you're joking.

The Big Bang Theory was on channel 4, and there's already been a second
series - the third's coming soon.

Well I meant whatever that dire thing on Monday's is with the bloke
they got rid of from The Gadget Show. :-)

On 9 Sep, 22:29, " wrote:
On 9 Sep, 22:10, "Steve Terry" wrote:

No steel framed building has EVER collapsed due to fire before 9/11, or
since. Yet we're expected to believe that at least THREE did that day.

No steel framed building fire has ever been fuelled by thousands of gallons
of aviation kerosene before.

I don't doubt that the impact and fires would have caused the collapse
of the towers but there is one bit that I have never understood.

I would have anticipated that the supports on one side of the building
would have failed, causing the tower to twist and fall sideways. Maybe
one side would collapse dragging the other side towards it. I would
never had anticipated that a building would pancake straight down into
it's own footprint, as all 3 did.


AIUI, most of the vertical load-bearing in the towers was through the
central core, so punching a big hole in the side or in one corner
isn't going to matter much.

--
Halmyre

wrote:
On 9 Sep, 23:00, Theodore wrote:

I really don't see why people have difficulty with all this. It only
takes one floor to give way and the weight and force of the building
above collapsing onto the next floor causes the pancaking effect.


Yes, if the one floor goes straight down.
If one side of a floor collapses, the floor below will collapse at the
same side; the building falls sideways.

No - that involves the addition of an immense amount of momentum to move
it sideways.


The question remains the same. How would you get one floor to go
straight down to initiate a straight-down collapse of the building? Is
it likely that would happen?

Very - it's the most energetically favoured mode of collapse

Halmyre wrote:
On 9 Sep, 22:29, " wrote:
On 9 Sep, 22:10, "Steve Terry" wrote:

No steel framed building has EVER collapsed due to fire before 9/11, or
since. Yet we're expected to believe that at least THREE did that day.
No steel framed building fire has ever been fuelled by thousands of gallons
of aviation kerosene before.
I don't doubt that the impact and fires would have caused the collapse
of the towers but there is one bit that I have never understood.

I would have anticipated that the supports on one side of the building
would have failed, causing the tower to twist and fall sideways. Maybe
one side would collapse dragging the other side towards it. I would
never had anticipated that a building would pancake straight down into
it's own footprint, as all 3 did.


AIUI, most of the vertical load-bearing in the towers was through the
central core, so punching a big hole in the side or in one corner
isn't going to matter much.


Not sure that was true..however one reason no one gout out above the
fire, was that all the core was also on fire and destroyed.

And its where all the lifts and stairs were.

So it doesn't make a lot of difference.

No steel building is designed to withstand a fire. Its designed to delay
structural damage to allow people to get out, and firefighters time to
get the fire under control.

In this case it was so extensive a fire that people could not get out,
no could the fire be brought under control.

--
Halmyre

"Brian Morrison" wrote in message
k...


If any fire protection material that could cope with an airliner
collision at full speed exists, I would be surprised. The WTC had
sprayed on material on the steel beams, naturally such stuff is fairly
crumbly and works by ablating and taking heat with it. It isn't
mechanically strong.

Such fire protection does exist.
It's called 'intumescent paint'.

Col

On 10 Sep, 08:14, The Natural Philosopher
wrote:
Halmyre wrote:
On 9 Sep, 22:29, " wrote:
On 9 Sep, 22:10, "Steve Terry" wrote:

No steel framed building has EVER collapsed due to fire before 9/11, or
since. Yet we're expected to believe that at least THREE did that day.
No steel framed building fire has ever been fuelled by thousands of gallons
of aviation kerosene before.
I don't doubt that the impact and fires would have caused the collapse
of the towers but there is one bit that I have never understood.

I would have anticipated that the supports on one side of the building
would have failed, causing the tower to twist and fall sideways. Maybe
one side would collapse dragging the other side towards it. I would
never had anticipated that a building would pancake straight down into
it's own footprint, as all 3 did.

AIUI, most of the vertical load-bearing in the towers was through the
central core, so punching a big hole in the side or in one corner
isn't going to matter much.

Not sure that was true..however one reason no one gout out above the
fire, was that all the core was also on fire and destroyed.


Right enough, the walls of the WTC were load-bearing, or at least
shared the load with the core.

--
Halmyre

"Brian Morrison" wrote in message
k...
On Thu, 10 Sep 2009 08:31:08 +0100
"Col" wrote:


"Brian Morrison" wrote in message
k...


If any fire protection material that could cope with an airliner
collision at full speed exists, I would be surprised. The WTC had
sprayed on material on the steel beams, naturally such stuff is fairly
crumbly and works by ablating and taking heat with it. It isn't
mechanically strong.

Such fire protection does exist.
It's called 'intumescent paint'.

Does it still work when the paint is covered in burning jet fuel and
the temperature is 1000 degrees C?

Yes!
And that's the whole point.
The paint is activated by high temperatures to form an insulating char
(a bit like polyurethane foam, only much harder) that protects the steel
from the heat and stops it from softening.

Col

" wrote in message
...


The question remains the same. How would you get one floor to go
straight down to initiate a straight-down collapse of the building? Is
it likely that would happen?

You won't find that out by studying the twin towers as they didn't collapse
straight down.
The tops tilted a good few degrees before they fell onto the lower floors
causing the whole lot to drop down within a smallish area.

Once there was enough weight to collapse the undamaged floors the whole
thing was contained inside the tube formed by the outer frame as the floor
trusses pulled the sides in. Thus it is very likely that the bottom of the
building will collapse straight down the tube. If you look at the videos you
can see each floor drop onto the lower ones and the sides pull in.

It won't make any difference to you of course as you have already decided
what happened and will ignore the truth.


What gets me is how many people in a burning building continued to work.
The first rule in the UK is to get out of a burning building and this cut
the death toll amongst the British companies in the trade centre as they
just left the building. Its also the reason why British skyscrapers are not
as high, you have to be able to exit a burning building by law. There is no
way the trade centre towers could have been built in the UK as they were
inherently unsafe in a fire.

Brian Morrison wrote:
On Thu, 10 Sep 2009 08:31:08 +0100
"Col" wrote:

"Brian Morrison" wrote in message
k...

If any fire protection material that could cope with an airliner
collision at full speed exists, I would be surprised. The WTC had
sprayed on material on the steel beams, naturally such stuff is fairly
crumbly and works by ablating and taking heat with it. It isn't
mechanically strong.
Such fire protection does exist.
It's called 'intumescent paint'.

Does it still work when the paint is covered in burning jet fuel and
the temperature is 1000 degrees C?

yes, for a time.

Ultimately all fire protection of steel is about the insulating of the
structure, and the energy used to sublimate the coating..but eventually,
a fire hotter than the melting point of steel, will destroy the steel.
You can buy time, but not prevent failure.


Regulations say about 45 minutes, and the WTC lasted 52 I think. A bit
longer on the second tower.

And a lot longer on WTC7 which didn't get smashed into and jet fuel
sprayed about, its just caught fire in sympathy ;-)


All three collapsed more or less in the same way. As you might expect.
And as many at the site, at the time, predicted. Leading to the infamous
'BBC reports collapse 30 minutes before it happened' story.

Col wrote:
"Brian Morrison" wrote in message
k...
On Thu, 10 Sep 2009 08:31:08 +0100
"Col" wrote:

"Brian Morrison" wrote in message
k...

If any fire protection material that could cope with an airliner
collision at full speed exists, I would be surprised. The WTC had
sprayed on material on the steel beams, naturally such stuff is fairly
crumbly and works by ablating and taking heat with it. It isn't
mechanically strong.
Such fire protection does exist.
It's called 'intumescent paint'.
Does it still work when the paint is covered in burning jet fuel and
the temperature is 1000 degrees C?

Yes!
And that's the whole point.
The paint is activated by high temperatures to form an insulating char
(a bit like polyurethane foam, only much harder) that protects the steel
from the heat and stops it from softening.


For a few extra precious minutes ONLY.

Col

Halmyre wrote:
On 10 Sep, 08:14, The Natural Philosopher
wrote:
Halmyre wrote:
On 9 Sep, 22:29, " wrote:
On 9 Sep, 22:10, "Steve Terry" wrote:
No steel framed building has EVER collapsed due to fire before 9/11, or
since. Yet we're expected to believe that at least THREE did that day.
No steel framed building fire has ever been fuelled by thousands of gallons
of aviation kerosene before.
I don't doubt that the impact and fires would have caused the collapse
of the towers but there is one bit that I have never understood.
I would have anticipated that the supports on one side of the building
would have failed, causing the tower to twist and fall sideways. Maybe
one side would collapse dragging the other side towards it. I would
never had anticipated that a building would pancake straight down into
it's own footprint, as all 3 did.
AIUI, most of the vertical load-bearing in the towers was through the
central core, so punching a big hole in the side or in one corner
isn't going to matter much.
Not sure that was true..however one reason no one gout out above the
fire, was that all the core was also on fire and destroyed.


Right enough, the walls of the WTC were load-bearing, or at least
shared the load with the core.


I thought the walls were in fact glass by and large? it was the steel
frame that was load bearing. Once that went, the lot went.

--
Halmyre

"Halmyre" wrote in message
...

AIUI, most of the vertical load-bearing in the towers was through the
central core, so punching a big hole in the side or in one corner
isn't going to matter much.

That is clearly untrue.

The weight is supported on the ends of the floor trusses.
Therefore the load is on the inner core and the walls.
As there is more floor area alongside the walls a greater load will be near
the outside.
The walls must, therefore, support more weight than the core.

"The Natural Philosopher" wrote in message
...
Col wrote:


Yes!
And that's the whole point.
The paint is activated by high temperatures to form an insulating char
(a bit like polyurethane foam, only much harder) that protects the steel
from the heat and stops it from softening.


For a few extra precious minutes ONLY.

Incorrect.
Such paint systems are rated as giving up to 2hrs protection.

Col

"The Natural Philosopher" wrote in message
...
Brian Morrison wrote:
On Thu, 10 Sep 2009 08:31:08 +0100
"Col" wrote:

"Brian Morrison" wrote in message
k...

If any fire protection material that could cope with an airliner
collision at full speed exists, I would be surprised. The WTC had
sprayed on material on the steel beams, naturally such stuff is fairly
crumbly and works by ablating and taking heat with it. It isn't
mechanically strong.
Such fire protection does exist.
It's called 'intumescent paint'.

Does it still work when the paint is covered in burning jet fuel and
the temperature is 1000 degrees C?

yes, for a time.

Ultimately all fire protection of steel is about the insulating of the
structure, and the energy used to sublimate the coating..but eventually, a
fire hotter than the melting point of steel, will destroy the steel. You
can buy time, but not prevent failure.

A hydrocarbon fire will not reach the melting point of steel,
which is around1500C. Burning jet fuel will reach about 1100C.
That said, getting close to the melting point isn't really all that
important. At 550C, steel has half the strength it has at room
temperature and this temperature is taken as the 'time to failure'
for determining the fire rating for intumescent coatings.

Col

Yeti wrote:
Brian Morrison wrote:
Francis Burton wrote:
In article ,
Nomen Publicus wrote:
No plane crash has ever left as little wreckage as any of these four
crashes that day.
Ever seen the film of a test where a jet fighter was driven into a concrete
block at 600 MPH? Nothing bigger than 5in across remained at the end.
Was it this one?

http://www.youtube.com/watch?v=DlXHl_Suv8g
Can't look at that now, but it was an F-4 and was part of an
investigation into the risks of an aircraft crashing into a nuclear
power plant.


You've surely seen the train (Class 55 I think it was, or a 45?)
ploughing into the UK nuclear flask?

Class 37 or 40 I thought, and yes, I've seen it.


You seen the subsequent claims from greenpeace that it was all rigged,
and part of a conspiracy? What utter crap.... :P

They said that the critical flask valve was protected by how the flask
was positioned. Of course, that couldn't happen in a real accident could
it? It was an expensive demonstration of the fact that such a flask can
survive a massive impact. Equally you could create a similar
demonstration where the flask fails.

I read a report about how some fairly radioactive thing that had been in
a UK power station (I think) was driven around in a similar flask, but
somehow there was an open aperture through which X and gamma rays were
passing at a level that would have badly injured or killed anyone in the
beam for more than a second or two. By pure luck, the beam was passing
down into the road surface and no one was injured.

So far, we've been lucky.

--

Brian

Col wrote:
"The Natural Philosopher" wrote in message
...
Col wrote:

Yes!
And that's the whole point.
The paint is activated by high temperatures to form an insulating char
(a bit like polyurethane foam, only much harder) that protects the steel
from the heat and stops it from softening.

For a few extra precious minutes ONLY.

Incorrect.
Such paint systems are rated as giving up to 2hrs protection.

Presumably not available in the early 1970s when WTC was built?

--

Brian

"Halmyre" wrote in message
...
On 9 Sep, 22:29, " wrote:
On 9 Sep, 22:10, "Steve Terry" wrote:
snip
AIUI, most of the vertical load-bearing in the towers was through the
central core, so punching a big hole in the side or in one corner
isn't going to matter much.
Halmyre


The twin towers were probably the most top loaded towers in the
world with hundreds of tons of air conditioners, aerial towers,
and water tanks, etc.
Then every floor under the roof loaded with furnishings,
office equipment and tons of paper

It's a miracle they didn't fall down under the best of conditions

Steve Terry

"Brian Morrison" wrote in message
...
Col wrote:
"The Natural Philosopher" wrote in message
...
Col wrote:

Yes!
And that's the whole point.
The paint is activated by high temperatures to form an insulating char
(a bit like polyurethane foam, only much harder) that protects the
steel
from the heat and stops it from softening.

For a few extra precious minutes ONLY.

Incorrect.
Such paint systems are rated as giving up to 2hrs protection.

Presumably not available in the early 1970s when WTC was built?

No, were're talking late 80s when these materials really took off.

Col

"Steve Terry" wrote in message
...

"Halmyre" wrote in message
...
On 9 Sep, 22:29, " wrote:
On 9 Sep, 22:10, "Steve Terry" wrote:
snip
AIUI, most of the vertical load-bearing in the towers was through the
central core, so punching a big hole in the side or in one corner
isn't going to matter much.
Halmyre


The twin towers were probably the most top loaded towers in the
world with hundreds of tons of air conditioners, aerial towers,
and water tanks, etc.

Water tanks?
Why didn't they just blow 'em to put out the fire like they did in
'The Towering Inferno'?
Sheesh....

Col

dennis@home wrote:


" wrote in message
...


The question remains the same. How would you get one floor to go
straight down to initiate a straight-down collapse of the building? Is
it likely that would happen?

You won't find that out by studying the twin towers as they didn't
collapse straight down.
The tops tilted a good few degrees before they fell onto the lower
floors causing the whole lot to drop down within a smallish area.

Once there was enough weight to collapse the undamaged floors the whole
thing was contained inside the tube formed by the outer frame as the
floor trusses pulled the sides in. Thus it is very likely that the
bottom of the building will collapse straight down the tube. If you look
at the videos you can see each floor drop onto the lower ones and the
sides pull in.

It won't make any difference to you of course as you have already
decided what happened and will ignore the truth.


What gets me is how many people in a burning building continued to work.
The first rule in the UK is to get out of a burning building and this
cut the death toll amongst the British companies in the trade centre as
they just left the building. Its also the reason why British skyscrapers
are not as high, you have to be able to exit a burning building by law.
There is no way the trade centre towers could have been built in the UK
as they were inherently unsafe in a fire.

Total ********.

The trade centers were build in accordance with very similar laws. The
central areas were escape routes, had more than one means of use, and
were fireproofed. The were not however built like bunkers to withstand
a direcdt hit from an aircraft.

The planes sliced right through the middle. It wasn't JUST a fire. It
was a fire that started across 2-3 floors simultaenously. And included
the escape routes. The top was cut off from the bottom.

I would guess that 99% of people above the impact died, and 99% below
made it out.

dennis@home wrote:


"Halmyre" wrote in message
...

AIUI, most of the vertical load-bearing in the towers was through the
central core, so punching a big hole in the side or in one corner
isn't going to matter much.

That is clearly untrue.

The weight is supported on the ends of the floor trusses.
Therefore the load is on the inner core and the walls.
As there is more floor area alongside the walls a greater load will be
near the outside.
The walls must, therefore, support more weight than the core.



whilst you are reasonably correct that the outside structure was pretty
load bearing, your reasoning is totally false.

It would be completely possible to build a tower with floors
cantilevered out from a central column, and having no walls at all.

I.e. the walls do not HAVE to be load bearing, it just happens in this
case they were, or at least the steel columns were. The walls were not,
being mainly glazing IIRC.

I've skipped over most of this thread - because I don't have time right
now. I'll catch up later.

If found this - and it's too funny NOT to post.

Col wrote:
"The Natural Philosopher" wrote in message
...
Col wrote:

Yes!
And that's the whole point.
The paint is activated by high temperatures to form an insulating char
(a bit like polyurethane foam, only much harder) that protects the steel
from the heat and stops it from softening.

For a few extra precious minutes ONLY.

Incorrect.
Such paint systems are rated as giving up to 2hrs protection.


gosh, 120 minutes!

whereas standard techniques are good for 60-100 minutes. Big deal.

The people wont survive 5 minutes in a fire like that.


Col

Col wrote:
"The Natural Philosopher" wrote in message
...
Brian Morrison wrote:
On Thu, 10 Sep 2009 08:31:08 +0100
"Col" wrote:

"Brian Morrison" wrote in message
k...

If any fire protection material that could cope with an airliner
collision at full speed exists, I would be surprised. The WTC had
sprayed on material on the steel beams, naturally such stuff is fairly
crumbly and works by ablating and taking heat with it. It isn't
mechanically strong.
Such fire protection does exist.
It's called 'intumescent paint'.
Does it still work when the paint is covered in burning jet fuel and
the temperature is 1000 degrees C?

yes, for a time.

Ultimately all fire protection of steel is about the insulating of the
structure, and the energy used to sublimate the coating..but eventually, a
fire hotter than the melting point of steel, will destroy the steel. You
can buy time, but not prevent failure.

A hydrocarbon fire will not reach the melting point of steel,

Odd that, since a bessemer converter is wholly carbon fuelled, and is
used to melt steel.

And in fact all steel is traditionally made using carbon fuels.


which is around1500C. Burning jet fuel will reach about 1100C.

Yeah sure, that's why they use special alloys in the exhaust of jet
engines.reheat gets up to a lot more than you might think. The
temperature is a function of the air blast I suppose, and a tall
building with a nice service area chimney can create quite a blast..

I suppose an oxy acetylene welder isn't a hyrdocarbon fuel fire
either..sure melts steel tho.



That said, getting close to the melting point isn't really all that
important. At 550C, steel has half the strength it has at room
temperature and this temperature is taken as the 'time to failure'
for determining the fire rating for intumescent coatings.


Exactly.


Col

The Natural Philosopher wrote:

A hydrocarbon fire will not reach the melting point of steel,

Odd that, since a bessemer converter is wholly carbon fuelled, and is
used to melt steel.

And in fact all steel is traditionally made using carbon fuels.


And a lot of extra oxygen, blown through the charge.


which is around1500C. Burning jet fuel will reach about 1100C.

Yeah sure, that's why they use special alloys in the exhaust of jet
engines.reheat gets up to a lot more than you might think. The
temperature is a function of the air blast I suppose, and a tall
building with a nice service area chimney can create quite a blast..

In a jet engine you're worried about loss of strength, maintaining
clearances and service life, it *really* isn't a good idea to allow the
fast spinny bits to lose strength and collide with the stationary bits.


I suppose an oxy acetylene welder isn't a hyrdocarbon fuel fire
either..sure melts steel tho.


Come on TNP, you're surely fishing here....

--

Brian

Yeti wrote:


I've skipped over most of this thread - because I don't have time right
now. I'll catch up later.

If found this - and it's too funny NOT to post.

So you didn't!

Brian Morrison wrote:
The Natural Philosopher wrote:

A hydrocarbon fire will not reach the melting point of steel,
Odd that, since a bessemer converter is wholly carbon fuelled, and is
used to melt steel.

And in fact all steel is traditionally made using carbon fuels.


And a lot of extra oxygen, blown through the charge.

which is around1500C. Burning jet fuel will reach about 1100C.
Yeah sure, that's why they use special alloys in the exhaust of jet
engines.reheat gets up to a lot more than you might think. The
temperature is a function of the air blast I suppose, and a tall
building with a nice service area chimney can create quite a blast..

In a jet engine you're worried about loss of strength, maintaining
clearances and service life, it *really* isn't a good idea to allow the
fast spinny bits to lose strength and collide with the stationary bits.

I suppose an oxy acetylene welder isn't a hyrdocarbon fuel fire
either..sure melts steel tho.


Come on TNP, you're surely fishing here....

Not that much.

I've seen pictures of fire damaged steel frame buildings without
protection - typically warehouse or barn fires with flammable material
inside, and they may not have melted, but they sure buckle.


http://warehousenews.co.uk/wp-conten...arehouse-1.jpg

http://www.manchesterfire.gov.uk/our...ford-park.aspx

as a quick google reveals.

Now imagine a few thousand tons on top..