Why scale models are ineffective

[1337m4n]

You may have seen a number of Truthers try to make scale-models of the World Trade Center and use them to "prove" that the towers couldn't possibly have collapsed. Famous examples include Richard Gage with his cardboard boxes, and Heiwa with his pizza boxes and his (fake) $1 mil challenge.

These don't work. Read and learn this article about the Square-Cube Law (http://tvtropes.org/pmwiki/pmwiki.php/Main/SquareCubeLaw).

Did you read it? No you didn't. Stop trying to skip ahead. Read it, I say!

Okay now. If you magically double the dimensions of a tower, its weight will increase by a factor of eight, but the structure's load-bearing capacity will only increase by a factor of four.

This works in reverse, too--if you magically shrink the tower's dimensions by half, its weight will be reduced to 1/8th that of the original, while the load-bearing capacity will only be reduced to 1/4th.

Hence, all these 10- foot "scale models" Truthers have produced over the years to attempt to "prove" the towers couldn't have collapsed, are actually capable of holding a much greater percentage of their own weight than the actual, real-life Twin Towers. Even when you build them out of materials much weaker than steel (such as cardboard), they still have a significant advantage, due to the much smaller scale.


Of course, if you're smart, your intuition should've already told you that Gage and Heiwa's little experiments weren't painting the right picture, but I thought you might like to know the science behind it.

And I am interested in seeing Heiwa's rebuttal.

[Hokulele]

Also, it is rather difficult to scale things such as gravity.

Those darn constants...

[Reactor drone]

Even with significant scale models(half scale for instance) it's still difficult to predict the scaling effect in a lot of situations.
NIST's testing of the 17', half scale, and 35',full scale, floor truss models showed significant differences between the predicted and observed fire rating.

A tiny desktop model isn't going to tell you anything interesting,at least not about the model.

[psikeyhackr]

Ryan Mackey discussed this in his Hardfire #3.

You must scale on the basis of mass and strength not size.

But detailed data on the tower is required to do that. So why has Mackey been complaining about me demanding to know the tons of steel and concrete on every level?

You people contradict yourselves.

psik

[Reactor drone]

Ryan Mackey discussed this in his Hardfire #3.

You must scale on the basis of mass and strength not size.

But detailed data on the tower is required to do that. So why has Mackey been complaining about me demanding to know the tons of steel and concrete on every level?

You people contradict yourselves.

psik

Everybody but you knows,or can work out, that data from the published specifications.I see you still haven't done it.

[Dave Rogers]

But detailed data on the tower is required to do that. So why has Mackey been complaining about me demanding to know the tons of steel and concrete on every level?

Because it's already known to a sufficient degree of accuracy. I suggest, once again, that you read one of the few papers in the Journal of 9/11 Studies that has any actual merit, in which Gregory Urich answers the exact question that you continue obsessively to ask.

Dave

[Evilgiraffe]

Also, it is rather difficult to scale things such as gravity.

Those darn constants...

Easily fixed. Build your scale model inside a centrifuge. :D

[Justin39640]

Ryan Mackey discussed this in his Hardfire #3.

You must scale on the basis of mass and strength not size.

But detailed data on the tower is required to do that. So why has Mackey been complaining about me demanding to know the tons of steel and concrete on every level?

You people contradict yourselves.

psik

you understand that this isnt a "scaling conspiracy theory" thread
so the actual mass isnt important for this discussion
i think even you can figure out that a 5 foot scale model will have different load bearing capacities than a full size skyscraper

just in case people still dont understand and need a simple and familiar example
an ant can carry 50 times its own weight - due to scaling
a 150lb ant wouldnt be able to do that (IIRC it would probably crush its legs and internal organs under its own weight)

[Grizzly Bear]

You may have seen a number of Truthers try to make scale-models of the World Trade Center and use them to "prove" that the towers couldn't possibly have collapsed. Famous examples include Richard Gage with his cardboard boxes, and Heiwa with his pizza boxes and his (fake) $1 mil challenge.

<snip>

And I am interested in seeing Heiwa's rebuttal.

Damn yooou!!!!!!!
You thought about the thread!!!!! Anyway I posted this before I put HI on ignore, maybe it'll have even more value to add here:

http://forums.randi.org/showpost.php?p=3983414&postcount=76
Say for example we have an umbrella shaped shelter that is 10 ft & 10 ft deep with a flat concrete roof 1 ft thick and a single center column having an area of 1ft2.

Concrete is roughly 150 Lbs/ft3, the total load on the column is about 15 kips, and the compressive stress is 15 kips/ft2

Note: 1 kip = 1,000 lbs

Take the same structure and increase the size 3 fold, overall size increases to 30 ft in each dimension; The roof slab would increase in thickness to by 3 fold as well resulting in a slab with about 2700 ft3, and a weight of 405 kips. The area of the center column would increase to 9 ft2. The column stress would be 45 kips, which is three times that of the original smaller structure. In order to effect the same compressive stress , the column area would have to triple to 27 ft2 with column dimension increasing to 5.2 ft on each side.


In other words even using the same materials in you "analogy" would result in drastically different results. The problem is compounded just by using different materials... A 1 ft3 volume of concrete can be loaded with many times it's own weight, however a slab of concrete the size of a building may only support double it's own weight.

[BigAl]

You may have seen a number of Truthers try to make scale-models of the World Trade Center and use them to "prove" that the towers couldn't possibly have collapsed. Famous examples include Richard Gage with his cardboard boxes, and Heiwa with his pizza boxes and his (fake) $1 mil challenge.

These don't work. Read and learn this article about the Square-Cube Law (http://tvtropes.org/pmwiki/pmwiki.php/Main/SquareCubeLaw).


Well written. I'll add that I've yet to see a Twoofer model in which the the structure damaged to simulate the plane impact and weight weight is added in proportion to the 100+ tons of aircraft to simulate unplanned floor overloading, and the model is stuffed with something like cotton and lighter fluid and set it alight.

[sylvan8798]

Scaling models is quite complicated. Obviously CT's like Gage try to make it too simplistic. Not only do you have to account for the scaling effects due to the difference in size, but it depends on what you are trying to learn from the model. They built scaled models of the towers and put them in wind tunnels during the design. Sometimes model ships are put in some liquid other than water. It's not as easy as pizza boxes and lemons, but it's not easy to convince people like Heiwa and Gage of that, apparently.

[Sword_Of_Truth]

Ryan Mackey discussed this in his Hardfire #3.

You must scale on the basis of mass and strength not size.

But detailed data on the tower is required to do that. So why has Mackey been complaining about me demanding to know the tons of steel and concrete on every level?

You people contradict yourselves.

psik

You mean like the way you did with your bamboo stick and toothpick model, or have we contradicted ourselves in some other way?

[jaydeehess]

Even with significant scale models(half scale for instance) it's still difficult to predict the scaling effect in a lot of situations.
NIST's testing of the 17', half scale, and 35',full scale, floor truss models showed significant differences between the predicted and observed fire rating.

A tiny desktop model isn't going to tell you anything interesting,at least not about the model.

Indeed because the ability of an item to shed heat through radiation and convection is proportional to its surface area but it ability to store heat is proportional to its volume thus making scaling in thermal properties extremely difficult if you also wish to scale strength.

IIRC, A sphere has the smallest surface are to volume ratio of any geometric shape. That fact should also be considered, the specific shape of an object matters.

[psikeyhackr]

Because it's already known to a sufficient degree of accuracy. I suggest, once again, that you read one of the few papers in the Journal of 9/11 Studies that has any actual merit, in which Gregory Urich answers the exact question that you continue obsessively to ask.

Dave
.
Gregory Urich does an interpolation on the exterior wall panels and he admits that. I have his spreadsheet. Why should anyone be interpolating something that the NIST should know and release and had 3 years to do?

psik

[psikeyhackr]

You mean like the way you did with your bamboo stick and toothpick model, or have we contradicted ourselves in some other way?
.
You are free to explain my supposed contradiction.

I compared the behavior of toothpicks without the mass of washers to toohpicks with the mass of washers. It should not be an intellectual challenge for normal people to extrapolate the significance of mass in the collaspe of the WTC.

Of course it could be a challenge for SOME people.

psik

[jaydeehess]

You mean like the way you did with your bamboo stick and toothpick model, or have we contradicted ourselves in some other way?

.
You are free to explain my supposed contradiction.

psik

English is a challenging language.

[psikeyhackr]

English is a challenging language.
.
It is for some people.

You mean like the way you did with your bamboo stick and toothpick model, or have we contradicted ourselves in some other way?
.
Go back and see what that was referring to.

psik

[TruthersLie]

psi

you seem to be missing the point.
your washers and toothpick attempt at scaling wasn't anywhere near accurate because toothipicks and washers are NOT scaled to anywhere near the rated strength of the stee as it would be scaled down.

It is one of the things that Ryan Mackey pointed out in his Physics of 9/11 part 3 interview on hardfire.

so while it is nice that toothpicks can be broken easily, that doesn't mean they have ANYWHERE near the same abilities as scaled down steel beams to the mass of the washers. (which is the POINT OF THE OP, which you seem to have missed)

[Justin39640]

.
You are free to explain my supposed contradiction.

I compared the behavior of toothpicks without the mass of washers to toohpicks with the mass of washers. It should not be an intellectual challenge for normal people to extrapolate the significance of mass in the collaspe of the WTC.

Of course it could be a challenge for SOME people.

psik

my model looks nicer :p
http://img32.imageshack.us/img32/6132/weights1.jpg

[psikeyhackr]

my model looks nicer :p
.
It also looks computer generated. Computers generated realities don't have to obey the laws of physics.

What is holding the disks up?

psik

[psikeyhackr]

psi

you seem to be missing the point.
your washers and toothpick attempt at scaling wasn't anywhere near accurate because toothipicks and washers are NOT scaled to anywhere near the rated strength of the stee as it would be scaled down.
.
There was NO ATTEMPT AT SCALING!!! I never said it was SCALED.

In fact both fo my videos ask about the steel and concrete on every level.

I compared collapses with NO WASHERS to collapses WITH WASHERS to show what effect of the falling mass having to accelerate stationary masses during the collapse.

Scaling can't be done without accurate information on the towers but then you people complain about my asking about the steel and concrete on every level.

Brilliant move guys. You people contradict the point. :D :D

psik

[Lupie]

.
It also looks computer generated. Computers generated realities don't have to obey the laws of physics.

What is holding the disks up?

psik

Just a neutral observation-I've been designing and building r/c aircraft for a few years now, mostly large scale stuff. I use a program to draw up the various parts and assemble the "virtual model" at which point I can test "fly" the model onscreen with all the various and relevant laws of physics and aerodynamics having an effect on the structural integrity and flight performance of the model. After having built the actual models and flight testing them in comparison to the virtual model, I've found It's quite accurate. Computer generated realities/models do have to obey the laws of physics if that is part of the program.

L.

[Sword_Of_Truth]

.
There was NO ATTEMPT AT SCALING!!!

Absolutely correct. You made no attempt to scale the model so that it accurately represented the collapses.

Instead you deliberately set it up so that it did what you wanted it to do.

I compared collapses with NO WASHERS to collapses WITH WASHERS to show what effect of the falling mass having to accelerate stationary masses during the collapse.

You wouldn't have wasted the effort if you truly understood that scale models aren't accurate.You're basically telling us that everyone elses scale models are wrong but yours.

The same way that you're telling us that it's ok for you to contradict yourself. :p

[Justin39640]

.
It also looks computer generated. Computers generated realities don't have to obey the laws of physics.

What is holding the disks up?

psik

yeah it obeys the laws of physics and like what was said before your models have no relevance as you control the scaled connections (tape or however you held up the washers)

that makes me wonder
was that the only size washer you tried?
i think to be fair you should have had at least 5 different mass washers just to compare results

try that again
this time use 3/4" ID fender washers (pretty heavy) and tape
or go to the metal shop and have them cut some disks for you from some round stock and drill some holes

but you wont

[Heiwa]

And I am interested in seeing Heiwa's rebuttal.

First you must decide what you are going to model, e.g. a steel tower structure where part C one way crushes part A, when C is dropped on A by gravity; C = 1/10 A, A carried C before.

How to go about it? And does size/scale matter? Let's do it full scale!

First select a suitable building standard to get the design stresses and the redundancy right. Let's also simplify and that only static design stresses due to gravity loads are considered (in this example).

Let's start with a very simple tower 100 floors high. It has a core of 8 vertical columns (100 floors high) in a square; three columns each side; 4 corner core columns and 4 intermediate columns. At every floor the core columns are interconnected with horizontal/slooping beams for redundancy reasons. The core is like a big mast of 8 columns. It is evidently self-supporting due to the beams between the core columns.

The core is surrounded by perimeter wall columns; say 7 each side, thus total 24! At every floor the perimeter core columns are interconnected with horizontal spandrels for redundancy reasons.

All the columns are primary, load bearing elements. At present no loads (except own weights) are applied to the columns. The horizontal beams and spandrels are secondary elements installed for redundancy reasons and act as support to keep critical stresses (buckling) low in the columns (as per the standard).

Now we connect the core columns with the perimeter columns with horizontal floor trusses! 5 perimeter columns at each wall corner are connected to one core corner column (thus 5 trusses) and the intermediate core columns are connected by one truss to the remaining, intermediate perimeter columns.

Thus there are 24 floor trusses between perimeter columns and core; 4 x 5 trusses connected to the core corner columns, 4 just between remaining columns. You follow? The trusses are just bolted to the columns. The trusses are secondary elements.

This can be done in any scale, size.

Now put a thin steel plate over all floor trusses and add your loads on the floor trusses.

These loads are evidently transmitted to the columns that compress the columns. Now ensure that the static stress in each column is according to standard. Evidently the corner core columns carry more load than any other column but ... the stresses are the same. The columns get heavier lower down.

Now check the structure for redundancy! Say that the criteria according to standard is that you can remove any one column between any floor and that the spandrels and the horizontal beams shall be able to transmit the column load around the 'failure' (the removed column bit) to adjacent coumns, that will not fail. It means, e.g. that the intermediate core columns become quite strong.

OK, your structure is ready. In any size, scale. The static stresses and the redundancy are as per standard.

Now we are going to remove all columns, one after the other, between parts C and A (so we can drop C on A).

Let's say we first remove one centre, the 4th middle one, perimeter wall column in one wall. No problem - there is redundancy enough.

Then we remove the two adjacent perimeter wall columns. What happens? Well, it is a possiblity that the 4th middle perimeter wall column above (and its local loads) will drop down to ground, the spandrels above connected to the 4th middle perimeter column shear off, unless the floor trusses (and the hat truss!) above can pull it (and the load!) in position.

Regardless, it seems that part C will be severely locally stressed and possibly damaged when we start removing columns between parts C and A, thus before C is even dropped on A.

This is another reason why part C cannot one way crush down part A. C is simply less strong than A and subject to bigger local loads due to local failures between C and A. There are many others. And none of them has to with scale or modelling. It is just simple structural damage analysis that is required and it is the same for any structure.

Anyone suggesting that you can remove all columns between parts C and A and then drop C on A is a fool. C is locally damaged before that, parts of C and loads should drop off an the remaining parts of C cannot crush down A.

Read my papers to get a better feel for the problem.

[alexi_drago]

Now but a thin steel plate over all floor trusses and add your loads on the floor trusses.



OK, your structure is ready. In any size, scale. The static stresses and the redundancy are as per standard.


These don't add up. If you make a small model that steel plate is gonna have to be thinner than aluminium foil, how much weight is that gonna exert on the floor trusses?

[Justin39640]

Anyone suggesting that you can remove all columns between parts C and A and then drop C on A is a fool. C is locally damaged before that, parts of C and loads should drop off an the remaining parts of C cannot crush down A.



isnt the heiwa challenge dropping part c squarely onto part a from any height?

i guess you just labeled yourself lol

[TruthersLie]

.
There was NO ATTEMPT AT SCALING!!! I never said it was SCALED.
psik

You are SOOOOO right. Yet here you are trying to point out that in your models (which had NO SCALING in them) that the washers failed to make it collapse.

Since you DIDNT bother with things like how scaling down, it would create massive problems, your model IS INVALID to be able to say, see... the models show it doesn't work.

don't you get that?

[Heiwa]

These don't add up. If you make a small model that steel plate is gonna have to be thinner than aluminium foil, how much weight is that gonna exert on the floor trusses?

Model is full scale! 1:1. Any size.

Anyone suggesting that you can remove all columns between parts C and A and then drop C on A is a fool. C is locally damaged before that, parts of C and loads should drop off an the remaining parts of C cannot crush down A. Are you one suggesting one-way crush down is possible?

[psikeyhackr]

You are SOOOOO right. Yet here you are trying to point out that in your models (which had NO SCALING in them) that the washers failed to make it collapse.

Since you DIDNT bother with things like how scaling down, it would create massive problems, your model IS INVALID to be able to say, see... the models show it doesn't work.

don't you get that?
.
Well then why did 1 washer on each toothpick 1 inch apart stop 20 washers that fell 12 inches faster than toothpick without washers? If anything I bet a created a situation more likely to collapse all of the way than the WTC. My toothpicks didn't get stronger all of the way down like EVERY SKYSCRAPER HAS TO. But you people don't insist on knowing the amount of steel on every level of the towers.

You can just BELIEVE things on the basis of inadequate data.

psik

[TruthersLie]

.
Well then why did 1 washer on each toothpick 1 inch apart stop 20 washers that fell 12 inches faster than toothpick without washers? If anything I bet a created a situation more likely to collapse all of the way than the WTC. My toothpicks didn't get stronger all of the way down like EVERY SKYSCRAPER HAS TO. But you people don't insist on knowing the amount of steel on every level of the towers.

You can just BELIEVE things on the basis of inadequate data.

psik

no instead you took a toothpick and used it as your support while adding weight.

BECAUSE YOU DIDN"T DO ANY SCALING, your model is invalid because 1. the toothpicks would need to be MUCH weaker, and the mass of the washers would need to be MUCh greater if you bothered to scale it.

it would be like me building a stupid 1/4 inch steel beam and then using thermite to cut it horizontally and saying "SEE, I proved that 9/11 was an inside job" An INVALID model is useless.

[alexi_drago]

Model is full scale! 1:1. Any size.

Anyone suggesting that you can remove all columns between parts C and A and then drop C on A is a fool. C is locally damaged before that, parts of C and loads should drop off an the remaining parts of C cannot crush down A. Are you one suggesting one-way crush down is possible?

That is not the topic.

and


Model is full scale! 1:1. Any size.


does not make any sense.

[Blender Head]

Square-Cube Law

Oh, so that is why "Eight-Legged Freaks" sucked both as a film and a science lesson!

[psikeyhackr]

no instead you took a toothpick and used it as your support while adding weight.

BECAUSE YOU DIDN"T DO ANY SCALING, your model is invalid because 1. the toothpicks would need to be MUCH weaker, and the mass of the washers would need to be MUCh greater if you bothered to scale it.
.
I was not trying to do a direct comparison to the WTC. I was comparing toothpicks without washers to toothpicks with washers. I demonstrated that STATIONARY MASS SLOWED THE FALLING MASS DOWN more than just toothpicks alone.

The point was that the distribution of mass of the WTC NEEDS TO BE KNOWN to analyze its supposed collapse. SCALING OF MY DEMONSTRATION IS IRRELEVANT.

But how can anyone scale it if THEY DON'T HAVE THE DATA? What were the weights of the 12 different types of exterior wall panels? How many of each type of wall panel were there? You complain that I didn't do what can't be done without data and then complain when I ask about the data.

And I ask about the data right in the videos. What were the tons of steel and tons of concrete on each level of the towers? :D :D :D

psik

[Justin39640]

.
I was not trying to do a direct comparison to the WTC. I was comparing toothpicks without washers to toothpicks with washers. I demonstrated that STATIONARY MASS SLOWED THE FALLING MASS DOWN more than just toothpicks alone.

The point was that the distribution of mass of the WTC NEEDS TO BE KNOWN to analyze its supposed collapse. SCALING OF MY DEMONSTRATION IS IRRELEVANT.

But how can anyone scale it if THEY DON'T HAVE THE DATA? What were the weights of the 12 different types of exterior wall panels? How many of each type of wall panel were there? You complain that I didn't do what can't be done without data and then complain when I ask about the data.

And I ask about the data right in the videos. What were the tons of steel and tons of concrete on each level of the towers? :D :D :D

psik


they weighed a lot
when things that weigh a lot fall down in the way they werent designed to
chaos ensues
get over it
planes plus fire equals (rule10)ed up (rule10)

(i think i drank too much at my friends engagement party lol :D)

[CORed]

The square cube law is yet another government fabrication, just like thermal expansion and gravity. Wake up sheeple!

[psikeyhackr]

they weighed a lot
when things that weigh a lot fall down in the way they werent designed to
chaos ensues
get over it
planes plus fire equals (rule10)ed up (rule10)

(i think i drank too much at my friends engagement party lol :D)
.
But what it hit didn't weigh a lot. It didn't have a lot of inertia to be overcome.

That "chaos ensues" is just like that idiotic"collapse was inevitable" crap from the NIST.

But I am sure you can't get over it.

psik

[Scott_Milner]

Also, it is rather difficult to scale things such as gravity.

Those darn constants...

Scale gravity? A few of you need to take basic physics classes again!

If you drop a bowling ball and a golf ball from the same height, at the same time, which will hit the ground first? You can even ignore air resistance for this example as it plays a very minor role.

[Dave Rogers]

Scale gravity? A few of you need to take basic physics classes again!

No, you need to progress a little beyond basic physics.

The structural strength of a building depends on the cross-sectional area of the support columns. Let's start with a building that has a safety factor of two. Build another, in which you multiply the width, depth and height of the building by six, and the structural strength increases by thirty-six times, but the weight increases by two hundred and sixteen times. Its weight is now three times higher than the structure can support; the building will fall down. However, build the second structure on the moon, where gravity is one-sixth of that on Earth, and the weight is now only thirty-six times that of the original building. Since the structural strength is thirty-six times higher, the safety factor is now back to two, and the building will stand up. That's what Hokulele means by "scale [things such as] gravity"; it can be used (in theory) to compensate for square-cube laws, but in practice there are one or two fairly major difficulties.

Dave

[Heiwa]

To model an impact of a structure C (WTC 1 top part) with a similar structure A (WTC 1 btm part) is quite easy and has nothing to with gravity or scale! Just ensure that C and A have similar structure and that A can carry C on top of A in a gravity field (just a simple test to ensure that C and A are load carrying structures) and that A = 10C. After that you can forget gravity and scale and proceed as follows on horizontal ground:

Put A on ground and fix it against a wall at one end! Then put some wheels on C so it can roll on ground. Now you can impact C into A at various velocities as you chose!

At low velocities you will probably notice that A and C deforms at impact and that C bounces back.

At higher velocities you will notice that weak elements in A and C fail, i.e. that C is getting damaged (the wheels may fall off!).

At a certain velocity you will notice that C is completely destroyed while big parts of A remain intact. Similar things will happen if you drop C on A ... in any scale and at any g.

[BigAl]

To model an impact of a structure C (WTC 1 top part) with a similar structure A (WTC 1 btm part) is quite easy and has nothing to with gravity or scale!

You don't have a clue what "model" and "scale" mean in the context of understanding structures.

[Justin39640]

You don't have a clue what "model" and "scale" mean in the context of understanding structures.

that was obvious with his water tank bs
he thought a campfire was a good scaled inferno lol

he also thinks snow cant crush a building lol

[sylvan8798]

I find Heiwa's obsession with his C and A "structures" as strange as psikey's fixation with the masses of steel and concrete at every location. I wonder what a psychiatrist would say about this type of obsessive behavior?

[Hokulele]

Scale gravity? A few of you need to take basic physics classes again!

If you drop a bowling ball and a golf ball from the same height, at the same time, which will hit the ground first? You can even ignore air resistance for this example as it plays a very minor role.


That is exactly my point, acceleration due to gravity is a constant*.

To take this back to scaling, now calculate how much force is required to stop the bowling ball? How much force is required to stop the golf ball? There is no way to scale gravity to make these forces equal, so there is no way you can call your golf ball and its behavior a perfect scale model of your bowling ball and its behavior.


* - At least for the purposes of model-building here on Earth, as Dave Rogers points out in his reponse.

[psikeyhackr]

That is exactly my point, acceleration due to gravity is a constant*.

To take this back to scaling, now calculate how much force is required to stop the bowling ball? How much force is required to stop the golf ball? There is no way to scale gravity to make these forces equal, so there is no way you can call your golf ball and its behavior a perfect scale model of your bowling ball and its behavior.

* - At least for the purposes of model-building here on Earth, as Dave Rogers points out in his reponse.
.
But if you have a series of bowling balls spaced in a tube with holes to let the air out and the top ball has to break the supports of the balls below then the mass of all of the balls is relevant to the acceleration that can occur because the top falling ball will try to force what it hits to accelerate faster than gravity. The conservation of momentum becomes a factor. So not knowing the distribution of mass through the tower is absurd.

The strength of the supports will be an additional factor in slowing things down.

http://www.youtube.com/watch?v=LXAerZUw4Wc

psik

[Hokulele]

But if you have a series of bowling balls spaced in a tube with holes to let the air out and the top ball has to break the supports of the balls below then the mass of all of the balls is relevant to the acceleration that can occur because the top falling ball will try to force what it hits to accelerate faster than gravity. The conservation of momentum becomes a factor. So not knowing the distribution of mass through the tower is absurd.


I recommend bacon bits and papaya seed dressing. They go with anything, even word salad.

And yes, your bizarre obsession with TONS of STEEL and TONS of CONCRETE is noted.

[FineWine]

First you must decide what you are going to model, e.g. a steel tower structure where part C one way crushes part A, when C is dropped on A by gravity; C = 1/10 A, A carried C before.

How to go about it? And does size/scale matter? Let's do it full scale!

First select a suitable building standard to get the design stresses and the redundancy right. Let's also simplify and that only static design stresses due to gravity loads are considered (in this example).

Let's start with a very simple tower 100 floors high. It has a core of 8 vertical columns (100 floors high) in a square; three columns each side; 4 corner core columns and 4 intermediate columns. At every floor the core columns are interconnected with horizontal/slooping beams for redundancy reasons. The core is like a big mast of 8 columns. It is evidently self-supporting due to the beams between the core columns.

The core is surrounded by perimeter wall columns; say 7 each side, thus total 24! At every floor the perimeter core columns are interconnected with horizontal spandrels for redundancy reasons.

All the columns are primary, load bearing elements. At present no loads (except own weights) are applied to the columns. The horizontal beams and spandrels are secondary elements installed for redundancy reasons and act as support to keep critical stresses (buckling) low in the columns (as per the standard).

Now we connect the core columns with the perimeter columns with horizontal floor trusses! 5 perimeter columns at each wall corner are connected to one core corner column (thus 5 trusses) and the intermediate core columns are connected by one truss to the remaining, intermediate perimeter columns.

Thus there are 24 floor trusses between perimeter columns and core; 4 x 5 trusses connected to the core corner columns, 4 just between remaining columns. You follow? The trusses are just bolted to the columns. The trusses are secondary elements.

This can be done in any scale, size.

Now put a thin steel plate over all floor trusses and add your loads on the floor trusses.

These loads are evidently transmitted to the columns that compress the columns. Now ensure that the static stress in each column is according to standard. Evidently the corner core columns carry more load than any other column but ... the stresses are the same. The columns get heavier lower down.

Now check the structure for redundancy! Say that the criteria according to standard is that you can remove any one column between any floor and that the spandrels and the horizontal beams shall be able to transmit the column load around the 'failure' (the removed column bit) to adjacent coumns, that will not fail. It means, e.g. that the intermediate core columns become quite strong.

OK, your structure is ready. In any size, scale. The static stresses and the redundancy are as per standard.

Now we are going to remove all columns, one after the other, between parts C and A (so we can drop C on A).

Let's say we first remove one centre, the 4th middle one, perimeter wall column in one wall. No problem - there is redundancy enough.

Then we remove the two adjacent perimeter wall columns. What happens? Well, it is a possiblity that the 4th middle perimeter wall column above (and its local loads) will drop down to ground, the spandrels above connected to the 4th middle perimeter column shear off, unless the floor trusses (and the hat truss!) above can pull it (and the load!) in position.

Regardless, it seems that part C will be severely locally stressed and possibly damaged when we start removing columns between parts C and A, thus before C is even dropped on A.

This is another reason why part C cannot one way crush down part A. C is simply less strong than A and subject to bigger local loads due to local failures between C and A. There are many others. And none of them has to with scale or modelling. It is just simple structural damage analysis that is required and it is the same for any structure.

Anyone suggesting that you can remove all columns between parts C and A and then drop C on A is a fool. C is locally damaged before that, parts of C and loads should drop off an the remaining parts of C cannot crush down A.

Read my papers to get a better feel for the problem.


Your papers have been shown by real engineers to be incompetent rubbish.

[FineWine]

.
Well then why did 1 washer on each toothpick 1 inch apart stop 20 washers that fell 12 inches faster than toothpick without washers? If anything I bet a created a situation more likely to collapse all of the way than the WTC. My toothpicks didn't get stronger all of the way down like EVERY SKYSCRAPER HAS TO. But you people don't insist on knowing the amount of steel on every level of the towers.

You can just BELIEVE things on the basis of inadequate data.

psik


The real engineers, who are much smarter and know vastly more than you, regard your obsessive claims as nonsense. Why are they wrong? How do you know things they don't?

[FineWine]

.
But what it hit didn't weigh a lot. It didn't have a lot of inertia to be overcome.

That "chaos ensues" is just like that idiotic"collapse was inevitable" crap from the NIST.

But I am sure you can't get over it.

psik


A thousand engineers, physicists, architects, and fire safety experts state that "collapse was inevitable." One poorly educated, agenda-driven crank says that they are all wrong. What do you know that they don't, and how did you learn it. (You'll get tired before I do.)

[Scott_Milner]

No, you need to progress a little beyond basic physics.

The structural strength of a building depends on the cross-sectional area of the support columns. Let's start with a building that has a safety factor of two. Build another, in which you multiply the width, depth and height of the building by six, and the structural strength increases by thirty-six times, but the weight increases by two hundred and sixteen times. Its weight is now three times higher than the structure can support; the building will fall down. However, build the second structure on the moon, where gravity is one-sixth of that on Earth, and the weight is now only thirty-six times that of the original building. Since the structural strength is thirty-six times higher, the safety factor is now back to two, and the building will stand up. That's what Hokulele means by "scale [things such as] gravity"; it can be used (in theory) to compensate for square-cube laws, but in practice there are one or two fairly major difficulties.

Dave

It is a response such as this that keeps me away from this forum.

We are not comparing a building on Earth vs. the moon, and therefore there is no need to 'scale' gravity. The fact that weight = mass x gravity should automatically tell you that a smaller scale building will proportionaly adjust loading on the support columns for a comparitive test.

If you scale down gravity on top of scaling down the mass of an object, then you are reducing the loading by an unfair factor!

[R.Mackey]

It is a response such as this that keeps me away from this forum.

We are not comparing a building on Earth vs. the moon, and therefore there is no need to 'scale' gravity. The fact that weight = mass x gravity should automatically tell you that a smaller scale building will proportionaly adjust loading on the support columns for a comparitive test.

If you scale down gravity on top of scaling down the mass of an object, then you are reducing the loading by an unfair factor!


Scott:

Welcome to the Forums.

Dave Rogers is Ph.D. in Physics, so he knows what he's talking about. Try to read his answers in context, they actually do make sense.

I gave my own treatment of scaling in precisely this situation on Hardfire some months ago; see here (http://www.youtube.com/watch?v=ZsDn6es7mtk) for video treatment, or read the slides here (http://911myths.com/index.php/Image:911physics_big.ppt). As that discussion demonstrates, it would be nice if we could change gravity to help with scaling, but of course we can't.

[Scott_Milner]

That is exactly my point, acceleration due to gravity is a constant*.

To take this back to scaling, now calculate how much force is required to stop the bowling ball? How much force is required to stop the golf ball? There is no way to scale gravity to make these forces equal, so there is no way you can call your golf ball and its behavior a perfect scale model of your bowling ball and its behavior.


* - At least for the purposes of model-building here on Earth, as Dave Rogers points out in his reponse.

The force required to stop the golf ball will be proportional to the force required to stop the bowling ball if scaled properly.

Once again, if you reduce the mass of the objects in the scaled model, the kinetic energy available also decreases. It is the potential enery and kinetic energy totals that are of interest, along with the action of gravity acting on the structure.

If F= m x a you can change either mass, or acceleration to produce the force. In your example if you scale one box column to 1/10th of the original and THEN reduce the acceleration of gravity the ratio is no longer 10:1 with respect to weight and potential energy.

[Hokulele]

The force required to stop the golf ball will be proportional to the force required to stop the bowling ball if scaled properly.

Once again, if you reduce the mass of the objects in the scaled model, the kinetic energy available also decreases. It is the potential enery and kinetic energy totals that are of interest, along with the action of gravity acting on the structure.

If F= m x a you can change either mass, or acceleration to produce the force. In your example if you scale one box column to 1/10th of the original and THEN reduce the acceleration of gravity the ratio is no longer 10:1 with respect to weight and potential energy.


Exactly. It would proportional, while the strength of the 1/10 box column is not proportional to the full-scale version (the Square-Cube Law that is the topic of this very thread). Hence the need to scale gravity to make your box columns behave appropriately, or the need to scale gravity to have the effect of a golf ball match the effect of a bowling ball.

[Dave Rogers]

It is a response such as this that keeps me away from this forum.

And yet, here you are.

We are not comparing a building on Earth vs. the moon, and therefore there is no need to 'scale' gravity. The fact that weight = mass x gravity should automatically tell you that a smaller scale building will proportionaly adjust loading on the support columns for a comparitive test.

Let me try again. Weight = mass x gravity. Mass varies as volume, which varies as length cubed. Therefore weight varies as length cubed times gravity. Structural strength varies as cross-sectional area, which varies as length squared. Therefore, if you scale down the entire building by a given factor, without adjusting the relative sizes of the support structures, the only way to preserve the strength-to-weight ratio of the original building is to scale gravity inversely with length. As Hokulele pointed out, this is impractical; therefore, results on scale models are not expected to be the same as results on the full sized object.

If you scale down gravity on top of scaling down the mass of an object, then you are reducing the loading by an unfair factor!

Obviously. What I was pointing out is that scaling down gravity is needed if you scale up the dimensions of the object. An understanding of basic physics would allow one to draw the inference that, if you scale down the dimensions of the object, gravity needs to be scaled up. If you didn't get this, then it looks to me like you need to take basic physics classes again.

Dave

[Scott_Milner]

Let me try again. Weight = mass x gravity. Mass varies as volume, which varies as length cubed. Therefore weight varies as length cubed times gravity.

Of course.

Structural strength varies as cross-sectional area, which varies as length squared. Therefore, if you scale down the entire building by a given factor, without adjusting the relative sizes of the support structures,

Why would you not scale down the support structures? This is a scale model, correct?

2' x 2' x 10' box columns vs. 2' x 2' x 10' box columns, NOT 2' x 2' x 10' box columns vs. 1" x 1" x 10" tooth picks.

the only way to preserve the strength-to-weight ratio of the original building is to scale gravity inversely with length.

As Hokulele pointed out, this is impractical; therefore, results on scale models are not expected to be the same as results on the full sized object.

What does the 'work': gravity, mass, or the energy/force?

Obviously. What I was pointing out is that scaling down gravity is needed if you scale up the dimensions of the object. An understanding of basic physics would allow one to draw the inference that, if you scale down the dimensions of the object, gravity needs to be scaled up. If you didn't get this, then it looks to me like you need to take basic physics classes again.

Dave

See previous paragraph.

Take a scenario where the vertical component is removed. Use a rolling, or sliding object crashing into a stationary object. If you were to alter either acceleration, OR mass can you effectively "scale" the force? Yes, or no?

[Dave Rogers]

Why would you not scale down the support structures? This is a scale model, correct?

I said relative sizes; in other words, scale down everything by the same amount.

2' x 2' x 10' box columns vs. 2' x 2' x 10' box columns, NOT 2' x 2' x 10' box columns vs. 1" x 1" x 10" tooth picks.

No, because if you keep the column dimensions the same then you aren't scaling the columns.

Let's say you build a half-scale model. The support columns are scaled down to half the width and half the depth, giving one quarter the compressive strength. The total structure is scaled down to half the width, half the depth, and half the height, giving one eighth the mass. The strength to mass ratio has therefore doubled. The only ways to maintain the original strength to weight ratio are to change gravity, which we can't do, or not to scale everything the same.


What does the 'work': gravity, mass, or the energy/force?

That's a very strange question. The effect of gravity on the mass exerts a force which, when moving in the appropriate direction, does the work; the work done is equal to the change in gravitational potential energy. Therefore, the answer to your question, as far as I can offer a sensible one, is "all four of the above".

Take a scenario where the vertical component is removed. Use a rolling, or sliding object crashing into a stationary object. If you were to alter either acceleration, OR mass can you effectively "scale" the force? Yes, or no?

Yes, so arbitrarily changing the mass can correct the scaling error. Nobody's disputing that. However, a model with the mass arbitrarily altered to correct the scaling error is not a scale model.

Dave

[sylvan8798]

Let's say you build a half-scale model. The support columns are scaled down to half the width and half the depth, giving one quarter the compressive strength. The total structure is scaled down to half the width, half the depth, and half the height, giving one eighth the mass. The strength to mass ratio has therefore doubled. The only ways to maintain the original strength to weight ratio are to change gravity, which we can't do, or not to scale everything the same.

Can't one also potentially correct this by changing materials? Isn't that part of the question of what needs to be "scaled" in order to achieve a representative model? The scaling can be more than just a dimensional thing.


Yes, so arbitrarily changing the mass can correct the scaling error. Nobody's disputing that. However, a model with the mass arbitrarily altered to correct the scaling error is not a scale model.

Dave

Not a scale model if you only define scaling as scaling the dimensions, but that's too narrow of a definition, I think.;)

[Dave Rogers]

Can't one also potentially correct this by changing materials? Isn't that part of the question of what needs to be "scaled" in order to achieve a representative model? The scaling can be more than just a dimensional thing.



Not a scale model if you only define scaling as scaling the dimensions, but that's too narrow of a definition, I think.;)

Yes, these are both valid points. However, we then go on to what the truthers' response to these modifications would be. Suppose we construct a 1/10 scale model of the WTC, then reduce the strength of the main structural members by a factor of 10, and show that the model collapses in a similar manner to the real structure. Will the truth movement's response be "OK, that was a valid modification to compensate for the effects of scaling on the strength-to-weight ratio of the structure? Or will it be, "This test was invalid because the model was deliberately weakened in order to ensure collapse"?

Dave

[deep]

Yes, these are both valid points. However, we then go on to what the truthers' response to these modifications would be. Suppose we construct a 1/10 scale model of the WTC, then reduce the strength of the main structural members by a factor of 10, and show that the model collapses in a similar manner to the real structure. Will the truth movement's response be "OK, that was a valid modification to compensate for the effects of scaling on the strength-to-weight ratio of the structure? Or will it be, "This test was invalid because the model was deliberately weakened in order to ensure collapse"?


If the modifications were defined/documented/published before the construction of the model, and they remained unchanged for the duration of the test, then I would either disagree with the modifications before construction started or accept the results of the test.

In other words, I would have a problem if the modifications were changed after testing began, for whatever reason.

[~enigma~]

You may have seen a number of Truthers try to make scale-models of the World Trade Center and use them to "prove" that the towers couldn't possibly have collapsed. Famous examples include Richard Gage with his cardboard boxes, and Heiwa with his pizza boxes and his (fake) $1 mil challenge.

These don't work. Read and learn this article about the Square-Cube Law (http://tvtropes.org/pmwiki/pmwiki.php/Main/SquareCubeLaw).

Did you read it? No you didn't. Stop trying to skip ahead. Read it, I say!

Okay now. If you magically double the dimensions of a tower, its weight will increase by a factor of eight, but the structure's load-bearing capacity will only increase by a factor of four.

This works in reverse, too--if you magically shrink the tower's dimensions by half, its weight will be reduced to 1/8th that of the original, while the load-bearing capacity will only be reduced to 1/4th.

Hence, all these 10- foot "scale models" Truthers have produced over the years to attempt to "prove" the towers couldn't have collapsed, are actually capable of holding a much greater percentage of their own weight than the actual, real-life Twin Towers. Even when you build them out of materials much weaker than steel (such as cardboard), they still have a significant advantage, due to the much smaller scale.


Of course, if you're smart, your intuition should've already told you that Gage and Heiwa's little experiments weren't painting the right picture, but I thought you might like to know the science behind it.

And I am interested in seeing Heiwa's rebuttal.Is density the Rodney Dangerfield of scaling?

[Heiwa]

Actually models are good to predict full scale results, as long as you apply the correct scale factors. The resistance of a ship/model moving in the interface water/air, for example, depends on friction (surface drag) and shape (waves, etc being created), which scale differently but as long you adjust the speed and know what you are measuring you can predict full scale pretty good.

A moving ship impacting a big wave in interface wavy sea/air and associated load is more complex to model. Too many different scale factors! How to fake such a scale model test is described at http://heiwaco.tripod.com/eapp2.htm. Same company, SSPA, also recently faked model tests of the sinking of same the model; http://heiwaco.tripod.com/news.htm .

So scale models are not ineffective ... but very easy to fake.

[sylvan8798]

Yes, these are both valid points. However, we then go on to what the truthers' response to these modifications would be. Suppose we construct a 1/10 scale model of the WTC, then reduce the strength of the main structural members by a factor of 10, and show that the model collapses in a similar manner to the real structure. Will the truth movement's response be "OK, that was a valid modification to compensate for the effects of scaling on the strength-to-weight ratio of the structure? Or will it be, "This test was invalid because the model was deliberately weakened in order to ensure collapse"?

Dave

lol, their argument would be that you painted mini-nano-thermite on your model and detonated it by remote control.

[BigAl]

If the modifications were defined/documented/published before the construction of the model, and they remained unchanged for the duration of the test, then I would either disagree with the modifications before construction started or accept the results of the test.

In other words, I would have a problem if the modifications were changed after testing began, for whatever reason.

One use of models is to economically test a range of dimensions to find the optimal value for some criteria. Minimal air drag for plane or car would be a good example.


(There are lots of pontificating amateurs around here.)

[Scott_Milner]

You misunderstood my point about the box columns, however it's not important as I see the dilemma between choosing a model which produces a similar strength to weight ratio, or a model that replicates similar forces.

There is still a problem with the towers' falling, especially World Trade 7: finding an instance in history where fire accomplishes what only a well planned, properly executed controlled demo has done.

[funk de fino]

There is still a problem with the towers' falling, especially World Trade 7: finding an instance in history where fire accomplishes what only a well planned, properly executed controlled demo has done.

No, there's not a problem. Unless you are saying buildings do not collapse due to fire?

[Hokulele]

No, there's not a problem. Unless you are saying buildings do not collapse due to fire?


Please do not fall for Scott Milner's transparent attempt at changing the subject. There are umpteen threads regarding WTC7 and fire.

[Heiwa]

No, there's not a problem. Unless you are saying buildings do not collapse due to fire?

Well, I have tried to collapse a steel structure using normal fire or worse! Nothing really happened except some local deformations, where the fire was applied. No collapse!
See http://heiwaco.tripod.com/nist1.htm#6 .

Any ideas what went wrong in my experiment?

[Hokulele]

Or Heiwa's.

[KJC]

I don't think Heiwa has even commented on a video I showed him of C destroying A without the need for explosives.

[Dave_46]

Well, I have tried to collapse a steel structure using normal fire or worse! Nothing really happened except some local deformations, where the fire was applied. No collapse!
See http://heiwaco.tripod.com/nist1.htm#6 .

Any ideas what went wrong in my experiment?


Have you done that risk assessment/method statement for children using flammable liquids yet?

Dave_46

ETA or will you just ignore this, as you have done before?

[funk de fino]

Well, I have tried to collapse a steel structure using normal fire or worse! Nothing really happened except some local deformations, where the fire was applied. No collapse!
See http://heiwaco.tripod.com/nist1.htm#6 .

Any ideas what went wrong in my experiment?

yes

http://forums.randi.org/imagehosting/thum_1824447b1cfcfa7614.jpg (http://forums.randi.org/vbimghost.php?do=displayimg&imgid=10770)

Steel framed building, office contents fire, fought by firefighters. Steel parts collapsed.

ETA - Last comment on blatant derail.

[Dave Rogers]

If the modifications were defined/documented/published before the construction of the model, and they remained unchanged for the duration of the test, then I would either disagree with the modifications before construction started or accept the results of the test.

That's fine, if a set of modifications could be arrived at which you agreed with. It might not be possible even to get to that point.

Because there's more to it than the square-cube law; there's the gravitational potential energy, which varies as the fourth power of the dimensions, and the buckling resistance of the columns, which varies linearly. Energy absorbed in buckling goes as buckling stress times length, so that varies as the square of the linear dimension. So, in a one-hundredth scale model, for example, do we increase the weight by a factor of a hundred to compensate for the strength-to-weight ratio, but then find that collapse is arrested because the energy balance is now biased by a hundred times in favour of survival? Or do we increase the weight by ten thousand times to get the energy balance right, and then find that the structure can't support even a few per cent of its own static weight?

It seems to me that collapse progression scales differently to collapse initiation. And that, actually, is a far more fundamental problem than the square-cube law. If everything scaled the same, we could correct for it; but different properties scale differently with the same variables.

Dave

[Heiwa]

yes

http://forums.randi.org/imagehosting/thum_1824447b1cfcfa7614.jpg (http://forums.randi.org/vbimghost.php?do=displayimg&imgid=10770)

Steel framed building, office contents fire, fought by firefighters. Steel parts collapsed.

ETA - Last comment on blatant derail.

But not really upper part C crushing down lower part A. It seems there was nothing below the roof, part C, to crush down!

[stateofgrace]

But not really upper part C crushing down lower part A. It seems there was nothing below the roof, part C, to crush down!

Why do you have lie all the time ? you said

Well, I have tried to collapse a steel structure using normal fire or worse! Nothing really happened except some local deformations, where the fire was applied. No collapse!
See http://heiwaco.tripod.com/nist1.htm#6 .

Any ideas what went wrong in my experiment?

You said nothing about crushing you said collapse, so why are you now lying and trying to pretend you said crush ?

Stop derailing this thread with your lies and pathetic attempts to move goalposts.

[Heiwa]

Why do you have lie all the time ? you said



You said nothing about crushing you said collapse, so why are you now lying and trying to pretend you said crush ?

Stop derailing this thread with your lies and pathetic attempts to move goalposts.

Could you, please, provide a structure in any size and demonstrate the amazing process you suggest is natural, normal and possible!

[stateofgrace]

Could you, please, provide a structure in any size and demonstrate the amazing process you suggest is natural, normal and possible!

You have been provided with a structure that collapsed due to fire, that fact you ignored it is your problem.

Are you saying the structure did not collapse?

You said

Well, I have tried to collapse a steel structure using normal fire or worse! Nothing really happened except some local deformations, where the fire was applied. No collapse!

The structure collapsed, you as usual are wrong.

[Justin39640]

Well, I have tried to collapse a steel structure using normal fire or worse! Nothing really happened except some local deformations, where the fire was applied. No collapse!
See http://heiwaco.tripod.com/nist1.htm#6 .

Any ideas what went wrong in my experiment?

i guess you missed the part about scale in this thread

also what constitutes a "normal" fire?
how did you measure its temperature
how did you measure the steels temp?

[Myriad]

Well, I have tried to collapse a steel structure using normal fire or worse! Nothing really happened except some local deformations, where the fire was applied. No collapse!...

Any ideas what went wrong in my experiment?


What went wrong is that you did not perform the experiment, and that you are lying when you claim you did. If you had performed it, you would be able to answer the question of how you measured the temperature of the steel legs to determine that they reached 500 degrees C as you reported. You would have been able to answer it immediately, the first time I asked it.

Respectfully,
Myriad

[TruthersLie]

You misunderstood my point about the box columns, however it's not important as I see the dilemma between choosing a model which produces a similar strength to weight ratio, or a model that replicates similar forces.

There is still a problem with the towers' falling, especially World Trade 7: finding an instance in history where fire accomplishes what only a well planned, properly executed controlled demo has done.

Derail.

and a bad one.
a debunked one.

first time in history claim? Really? Look up august 1945... prior to then no city had been destroyed by a single bomb before either... after? 2 had.
are atom bombs fake?

start a new thread, or search out one and bring up your bs point.
/derail

[Dave Rogers]

There is still a problem with the towers' falling, especially World Trade 7: finding an instance in history where fire accomplishes what only a well planned, properly executed controlled demo has done.

Except that: (a) no well planned, properly executed controlled demolition has ever dropped a structural steel building anywhere near as large as WTC7, and (b) well planned, properly executed controlled demolitions normally cause a building to fall vertically into its own footprint, which WTC7 did not.

(a) is well known, in that the current world record for structural steel building demolition is still held by the J. L. Hudson department store in Detroit (http://www.controlled-demolition.com/default.asp?reqLocId=4); (b) is evident from the fact that videos of the WTC7 collapse show the building leaning several degrees south in the course of the collapse, and the debris pile spanned a four-lane highway adjacent to the south side of the building, as can be found from searching this forum.

Dave

[BigAl]

You misunderstood my point about the box columns, however it's not important as I see the dilemma between choosing a model which produces a similar strength to weight ratio, or a model that replicates similar forces.

There is still a problem with the towers' falling, especially World Trade 7: finding an instance in history where fire accomplishes what only a well planned, properly executed controlled demo has done.

Henry Guthard, 70, one of Yamasaki's original partners who also worked as the project manager at the [WTC] site, said, "To hit the building, to disappear, to have pieces come out the other side, it was amazing the building stood. To defend against 5,000 (sic) gallons of ignited fuel in a building of 1350 feet is just not possible.

Report From Ground Zero
http://snurl.com/j54gc (Bottom of page 188)

There was no man-made explosive seen or heard at WTC. Prove me wrong.
10 seconds of video or one clear unambiguous quote will do it. No such quote or video exists.

Here are more steel structures that failed due to only fire.



January of 1997 -- the $15 million dollar Sight and Sound Theater in
Lancaster County, Pa collapsed due to fire.

http://www.interfire.org/res_file/pdf/Tr-097.pdf


Historical Survey of Multistory Building Collapses Due to Fire
By: Jesse Beitel and Nestor Iwankiw, Ph.D., P.E.
http://www.fpemag.com/archives/article.asp?issue_id=27&i=153

On Jan 16, 1967, the steel roof of the McCormick Place in Chicago
collapsed due to fire



Enigma Business Park fire
http://www.bbc.co.uk/herefordandworcester/content/articles/2006/11/03/malvern_fire_video_feature.shtml

Dutch fire
http://www.youtube.com/watch?v=ZaK5YVVaRCo


-------------------------------------------------
September/October 2002

Bridge Rebuilt on the Fast Track
by Timothy Barkley and Gary Strasburg

When a crash occurs on a main travel artery, it can back up traffic
for miles-causing a chain reaction affecting every route in the
vicinity. If the incident occurs at an interchange of three major
highways and destroys a well-traveled bridge, transportation officials
have the makings of a major congestion emergency.

This exact scenario occurred at the junction of Interstates 65, 20,
and 59 in downtown Birmingham, AL, on Saturday, January 5, 2002. At
approximately 10 a.m., a gasoline tanker truck hit the I-65 Southbound
bridge. Fire and heat caused the steel girders to sag up to 3 meters
(10 feet) on one side. The interchange was engulfed in smoke that
filled the skyline, visible to motorists and residents of the city.

-------------------------------------------------------------------

Steel building collapsses due to fire.

http://www.charleston.net/news/2007/jun/20/mourning_heroes/

Mourning 9 heroes
By Noah Haglund (Contact), Nadine Parks (Contact), Glenn Smith (Contact)
The Post and Courier
Wednesday, June 20, 2007


'Fearless' Charleston firefighters 'will never be forgotten,' Riley says

Capt. Ralph Linderman of the St. Andrews Fire Department said the
blaze was the hottest he could recall in three decades of
firefighting. "That fire bent steel like a wet noodle," he said.

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

----------------

(04-29) 12:51 PDT -- A huge ball of fire from an exploding
gasoline tanker melted steel and caused an overpass in the
MacArthur Maze near the East Bay end of the Bay Bridge to collapse
onto the roadway below early Sunday, virtually ensuring major
traffic problems for weeks to come.

The tanker, loaded with 8,600 gallons of unleaded gasoline, was
heading from a refinery in Benicia to a gas station on Hegenberger
Road, in Oakland, shortly before 4 a.m. when it crashed.

Engineers not connected to the incident said the steel underbelly
of the I-580 overpass seems to have heated to a sufficient
temperature to bend -- and that movement pulled the
roadbed off its supports.

"It was so much engulfed in flames, it was hard to see the freeway
itself," Rodriguez told KCBS radio. "It was scary because, you
know, it's metal and cement... You could see the freeway drooping.
It looked like plastic melted. It was unbelievable. It was bent
and finally it just fell and we saw it hit the ground."


http://sfgate.com/cgi-bin/article.cgi?f=/chronicle/archive/2007/04/29/BAGVOPHQU46.DTL

-------------------------------


1989 FIRE CLOSES I-78, FORCES DETOURS
http://www.nycroads.com/roads/I-78_NJ/

FIRE CLOSES I-78, FORCES DETOURS: In the early morning hours
of August 7, 1989, a multiple-alarm fire at an illegal garbage
dump underneath I-78 near Newark Airport caused heavy damage to
the freeway overpass. The source of the fire was a mound of
trash 25 feet tall and hundreds of yards long consisting of
scrap wood, plastics and paper. The heat of the fire buckled
the ten-inch concrete surface and melted steel support beams,
and the resulting weight shifts from the highway (which had
sagged nearly a foot)

[Dave_46]

Have you done that risk assessment/method statement for children using flammable liquids yet?

Dave_46

ETA or will you just ignore this, as you have done before?


Well, you have replied to two posts after this one, so I guess the answer is that you will ignore it.

Dave_46

[Heiwa]

Well, you have replied to two posts after this one, so I guess the answer is that you will ignore it.

Dave_46

Yes, because you are off topic. But safety at sea is my biz so I apply it ashore too. Don't worry. Any thoughts why my model didn't collapse due to severe fire/heat?

[Justin39640]

Yes, because you are off topic. But safety at sea is my biz so I apply it ashore too. Don't worry. Any thoughts why my model didn't collapse due to severe fire/heat?

wheres the video/pictorial archives of your test?
you wouldnt spend that time and money without recording the event, would you?

and i dont know how laws are in your neck of the woods
but i think id get in a good deal of trouble for lighting something like that in my yard if i didnt have the FD involved and standing by

your safety measure is a water can and to tell kids not to play with matches lol

[sylvan8798]

Because there's more to it than the square-cube law; there's the gravitational potential energy, which varies as the fourth power of the dimensions, and the buckling resistance of the columns, which varies linearly. Energy absorbed in buckling goes as buckling stress times length, so that varies as the square of the linear dimension. So, in a one-hundredth scale model, for example, do we increase the weight by a factor of a hundred to compensate for the strength-to-weight ratio, but then find that collapse is arrested because the energy balance is now biased by a hundred times in favour of survival? Or do we increase the weight by ten thousand times to get the energy balance right, and then find that the structure can't support even a few per cent of its own static weight?

It seems to me that collapse progression scales differently to collapse initiation. And that, actually, is a far more fundamental problem than the square-cube law. If everything scaled the same, we could correct for it; but different properties scale differently with the same variables.

Dave

Absolutely, which gets back to the point that what/how you scale depends on what you are looking for. It seems unlikely that you would model all the behaviors with one model. You might need several different model arrangements to capture the initiation, the global collapse, the sagging beams/pulling columns, etc. Truthers who think they can get anywhere with pizza boxes and lemons are seriously deluded. Better to burn the boxes for heat and make lemonade.:p

[Justin39640]

Absolutely, which gets back to the point that what/how you scale depends on what you are looking for. It seems unlikely that you would model all the behaviors with one model. You might need several different model arrangements to capture the initiation, the global collapse, the sagging beams/pulling columns, etc. Truthers who think they can get anywhere with pizza boxes and lemons are seriously deluded. Better to burn the boxes for heat and make lemonade.:p

in other words
a model built in a computer that cost a few million?

[stateofgrace]

Yes, because you are off topic. But safety at sea is my biz so I apply it ashore too. Don't worry. Any thoughts why my model didn't collapse due to severe fire/heat?

Your biz is not safety at sea, my company, the largest offshore sub sea construction company on the planet as records of all contracts carried out by all third party contactors, you are not listed. You are a lying fraud who when asked did not know the first thing about offshore safety.

List all the offshore projects your company as been awarded, with dates.

List all the safety recommendations that your company has put forward and as been adopted as standard by the entire offshore industry.

[Myriad]

Any thoughts why my model didn't collapse due to severe fire/heat?


The most likely possibility is that it didn't collapse because it was never exposed to severe fire/heat, because it never existed, because you never constructed it. You have not performed the test you've described and you are lying every time you state or imply that you did.

Respectfully,
Myriad

[FineWine]

Well, I have tried to collapse a steel structure using normal fire or worse! Nothing really happened except some local deformations, where the fire was applied. No collapse!
See http://heiwaco.tripod.com/nist1.htm#6 .

Any ideas what went wrong in my experiment?


It was designed by an uncomprehending fool.

[Dave_46]

Yes, because you are off topic. But safety at sea is my biz so I apply it ashore too. Don't worry. Any thoughts why my model didn't collapse due to severe fire/heat?

If I was off topic it was because I followed you off topic.

As to why your model didn't collapse,

1. I don't believe you carried out the test (see Myriad's comments)
2. See the title of this thread.

Dave_46

Have you done the risk assessment/method statement before encouraging children to mess with flammable liquids?

[GlennB]

List all the offshore projects your company as been awarded, with dates.



Heiwa was asked this a few years ago, here I think. The only real project he would admit to was 'welding lifeboat davits on a Med. ferry'. I found this strange for the proprietor of the "European Agency for Safety at Sea".

I have regular doubts about my own motivation for continuing to attack his nonsense. It's feeling a lot like bullying an unfortunate who knows no better. He hasn't published in professional journals the way he claims. He hasn't presented at learned conferences the way he claims. He doesn't hold several maritime patents, the way he claims. His Agency is a name only, and even the name is in breach of European law. He spews unscientific guff right, left and centre. He is a sad case. In a word - deluded.

So - over and out on the Heiwa front. Good luck all.

[Dave_46]

Heiwa was asked this a few years ago, here I think. The only real project he would admit to was 'welding lifeboat davits on a Med. ferry'. I found this strange for the proprietor of the "European Agency for Safety at Sea".

I have regular doubts about my own motivation for continuing to attack his nonsense. It's feeling a lot like bullying an unfortunate who knows no better. He hasn't published in professional journals the way he claims. He hasn't presented at learned conferences the way he claims. He doesn't hold several maritime patents, the way he claims. His Agency is a name only, and even the name is in breach of European law. He spews unscientific guff right, left and centre. He is a sad case. In a word - deluded.

So - over and out on the Heiwa front. Good luck all.

My bolding.

I understand what you are getting at. However, when he is promoting dangerous experiments for children I feel the need to bring it to peoples attention. I strongly suspect it will make no difference to him, but it helps my concience to know that I have not let his advocacy of stupidity pass without comment. And, I will continue to comment on it whenever I notice his advocacy.

Dave

[stateofgrace]

Heiwa was asked this a few years ago, here I think. The only real project he would admit to was 'welding lifeboat davits on a Med. ferry'. I found this strange for the proprietor of the "European Agency for Safety at Sea".

I have regular doubts about my own motivation for continuing to attack his nonsense. It's feeling a lot like bullying an unfortunate who knows no better. He hasn't published in professional journals the way he claims. He hasn't presented at learned conferences the way he claims. He doesn't hold several maritime patents, the way he claims. His Agency is a name only, and even the name is in breach of European law. He spews unscientific guff right, left and centre. He is a sad case. In a word - deluded.

So - over and out on the Heiwa front. Good luck all.

I also hear what you say and yes you are correct but I will not let remarks like he makes go unchallenged. It annoys me when I see him try hitching a ride on the backs of guys out there who do work in this industry. I have worked offshore for the last fourteen years, on various installations and vessels and on them all safety is paramount. There is not a single offshore operation that takes place unless it is safe. All offshore operations are task risked and it is the duty, of any individual out there to call a time out if an unsafe act takes place. Safety is a religion out there, heck the company I work for even as the “Do it safely or not at all" as its motto. Offshore contracts are awarded on safety records and removed if safety is poor. There is a massive effort by everybody out there to work safely and take it very seriously.

And this fraud as the nerve to try and claim some sort of credit for this massive effort, to try and jump on the bandwagon and take some sort of credit for safety at sea. There is a supreme effort to work safely out there; this effort is reinforced at every level. This massive effort takes place day in and day out and does so without any input from Heiwa. He is not responsible for safety at sea, in the industry I work in, at any level. The thousands of guys who work out there are.

Anyway I hear what you say and as such this will be my last comment on this topic in this thread and I would like to apologise to 1337m4n for being drawn into a derail by this fraud.

[Scott_Milner]

Please do not fall for Scott Milner's transparent attempt at changing the subject. There are umpteen threads regarding WTC7 and fire.

Changing what subject? Are you going to fall for the poor analogy of a tin building sagging from heat to explain a total collapse of WTC7? Do you see any concrete, or structural grade box columns as used in WTC1, 2, or 7 in that two level office structure? I think not.

Notice the photo of the office building on page two is not a total collapse.

[funk de fino]

Changing what subject? Are you going to fall for the poor analogy of a tin building sagging from heat to explain a total collapse of WTC7? Do you see any concrete, or structural grade box columns as used in WTC1, 2, or 7 in that two level office structure? I think not.

Notice the photo of the office building on page two is not a total collapse.

Not an office building it was a warehouse. The only reason the side columns did not collapse was because they were supported by concrete and brick walls. There was no weight on the roof section yet it still failed in a fought fire. WTC building fires were not fought.

Steel fails in fire, get over it. Stop moving OT again. Back to the OP and defend your earlier claims.

[Justin39640]

hmmm
ive never seen a building with tin structural supports