Joker and Greeny2,
Remember something about the planes which hit the WTC 1 and 2....the engines on those aircraft were mounted on the wings. They were not like the plane you posted about ..a single engine aircraft with the engine on the fuselage.
The engines on the passenger jets were pulling the fuselage along at whatever gross speed and weight. Thus also meaning the engines at the point of impact would be penetrating ..verses just wings or wing shear....at that penetrating speed. THe engines too would be a speeding penetrating object.
It was the same with the B25 Mitchell bomber which struck the Empire state building in the 1940s in a fog. One of the engines, if I remember correctly from reading so many years ago, penetrated the building and went down an elevator shaft and wound up down at the lobby.
No doubt the wings at some point sheared off before the fuselage...or the engines..but at what speed did the plane hit???
And the wings on these jets.. full of fuel...had great weight and mass...equalling penetrating ability...even for a wing. And remember...these are not the wings of a small plane..they must be able to withstand the wind speed and lift..weight of the fuel, engine vibrations, turns and banks..etc etc. Thus meaning they are suitably reinforced or engineered.
The C 130 photo or video you provided is of an older/earlier model of C 130 used for fire fighting. It suffered a massive structural failure with the weight of the fluids used in fire fighting. I remember that incident so many years ago. That plane should have been placed in a maintenance facility for some serious disassembly and structural X raying/non destructive testing as is often done at depot level maintenance facilities. Those firefighting planes are heavily loaded with liquids for the task.
It is obvious that there was a serious. massive, and sudden weight/maneuvering failure of the structure at the wing roots in flight.
I remember thinking the same years ago when I first saw that video. A tragedy in the midst of another tragedy.
April 9, 2009
I'm afraid you are talking to deaf ears Tom. Joker refused to do the one thing I asked him, objectively look at his own pictures that show clearly how these beam segment failed at the bolts. Instead he just spun the subject onto some Cesna wreck, and a bunch of links completly off subject. He is hung up on proving simple aluminum being not as strong as steel, but does not understand the physics of the WTC and anything about metalurgy. I did give him a link that gave tecnical data, he didn't even read it. It was very complete and very credible. People want to believe what they want to believe. And they wonder why people do not want to waste their time inventing the wheel over and over.
"greeney2" wrote: I'm afraid you are talking to deaf ears Tom. Joker refused to do the one thing I asked him, objectively look at his own pictures that show clearly how these beam segment failed at the bolts. Instead he just spun the subject onto some Cesna wreck, and a bunch of links completly off subject. He is hung up on proving simple aluminum being not as strong as steel, but does not understand the physics of the WTC and anything about metalurgy. I did give him a link that gave tecnical data, he didn't even read it. It was very complete and very credible. People want to believe what they want to believe. And they wonder why people do not want to waste their time inventing the wheel over and over.
I know aluminum is not as strong as steel. Which is why the building/buildings where structurally not made of aluminum.
Aluminum is not suited for certain applications at all.
But aluminum has certain properties which make it suitable for aircraft and able in this engineered/design capacity to carry certain loads satisfactorily. But at a certan mass and weight/load capacity....aluminum ...Just like a copper bullet is capable of penetrataing steel. And copper is certainly not as strong as steel..but at a certain weight and velocity is capable of penetrating and even cutting or blasting its way through steel of certain thickness.
Which is why I asked the velocity and gross weight of the airplane.
I have not taken physics in school and my math is severly lacking..but I have shot enough bullets in my time to know what a certain caliber bullet will do to steel of certain thickness...though copper bullets are not as strong per se as steel.
And I am talking about plain olde copper and lead bullets...both metals not as strong as steel.
Also as you alluded to or spoke concerning ...a sudden weighty impact of a certain shock weight/velocity will shear off fasteners as well.
Thanks for your post Greeny.
April 9, 2009
Exactly, and if you look at the pictures joker gave carfully, you can count the beams and determain its the width and height of a 767, as the 3 beam segments were 10 feet wide, 3 per each 10 feet. You can clearly see level breaks between 3 beam segments meaning they sheered at the bolting lines. What is supose to be a human standing is probably jagged metal torn that appears like a pair of legs, or its just photo shopped. No possible way within that hour, could any human walk were that inferno was.
Last, and I'mfinished with this nonsense, the 767 were the biggest variants of the 767 series, and heaviest. Joker just fails to understand this is not a simple example of Aluminum strength, and comparing it to aluminum foil is ridiculas. Its a dumb as comparing a soft lead solgier or fishing sinker, and claim a 44 magnum could not hurt you that is the same weight. Understanding bullets is simple, bigger projectile with greater speed is more. 767's fully loaded, throttling up at 500 MPH and 20,000 pounds of JP4, is not a Cesna going 125 mph with 80 gallons of gas.
People who work in Aerospace of other material industries understand this, but those with no background in it beleive the crap on the internet, like thinking steel melts at 2800 degrees, until then its still OK and will hold a building. They do not understand the grain transformations that begin at 600-700 degrees, how heat treating is affected, and strength.
Aluminum....LOL LOL LOL Greeny2.
I should not laugh as this is a serious topic.
Until I began working in this shipyard I never knew much about aluminum. I thought all aluminum was basically thicker versions of the tin cans out of which many of us drink beverages. I knew nothing about various alloys and blends of aluminum or even other metals.
There are numerous blends of aluminum ..such as the heavy duty blends used for example in a motorcycle transmission. Much stronger blend than what one gets in a drink can.
Same with structural Aluminum. It is not just the aluminum per se which gives it it's strength..but the shape. The same could be said for steel...T bar or I beams etc. The Ribs of the aircraft so to speak. A submarine is not just the sheet steel you see on the outside...but the large specially shaped Ribs on the inside to which the plate is welded just so...just to specification. The same for aircraft structural plate etc etc. Even the skin is not aluminum as one gets in a drink beverage can.
This shipyard was the first place I had ever seen Industrial grade aluminum foil..and it is a far cry from the stuff one gets in the grocery stores. Very thick. But it is still foil..and properly folding and shaping it is what gives it strength ..just like any metal.
Even the plastic bags we use are a far cry from what one gets at the grocery store or department store. Very very thick as plastic bags go.
Most peoples have never been exposed to such a concept, product or understanding of the world around us.
Though it has been years since I found it lying around at a yard sale.. ..I still have in my junk bin outside two high pressure check valves from an aircraft application..they are nothing like what one gets at Auto Zone or Advance Auto or Home depot. Very very light material...for the high pressure usage for which they are designed.
Well nonetheless...agree... weaker metals ..properly used at a certain velocity plus mass can penetrate stronger metals...no problem.
Thanks for your input on this sensitive subject. I did not intend to cause any angst among posters here but my limited experience in this shipyard tells me it is not a problem for a plane to cut through or break down steel on sudden impact.
Oh...by the way...the other night coming home from work on my scooter..one of the steel allen bolts holding on my Plexiglas windshield broke just going down the road. Vibration over a few months...and it sheared off and fell down on the floor board. Vibration will shear off steel as well. And Vibration is a smaller weaker form of sudden shock impact..spread over longer time period/periods.
Last night I took the windshield off the scooter when I got home and punch marked the center of the sheared off bolt and slowly and methodically began drilling it out ..first with smaller drill bits and working up to larger ones. I had super glued it in there with this semi hardening super glue.
I was able to get it out without damaging the threads and replaced it with another 5/16ths 18 thread bolts and the scooter is now back on line.
Steel has no problem under the right conditions ..shearing off ...bolts as well as plate or t bar..I beam. Vibration alone is capable of changing conditions as well as heat and cold. Quite correct. And it does not need to get to melting temperatures.
I've done optical alignment on these ships and you can watch the cross hairs in the K&E alignment scope move many thousands of an inch when the sun goes down and the steel begins cooling.
I have seen a crack in a submarine hull ...HY 80 high grade steel...start to run like a crack on a fiberglass Corvette. Bad JuJu...very bad bad JuJu!!! Glad someone caught that one...big time.
Thanks again for your input.
April 9, 2009
I love nothing more than talking metalurgy which were my favorite classes. An Aluminum can alloy contains elements to make it very ductile so they can take a flat disc shape, and stamp it extruding the shape of the 6" tall can. You could not do that with the sheet metal used for aircraft skin, it has different elements or % to add different properties. The other ingrediant to all alloys is the condition of heat treating, that hardens the material. Aluminum cans or aluminum foils usually are fully anealed, which makes them soft, plyable, and ductile. Structural alloys are heat treated, by Precipition process, where they go into controlled furnaces, at exact temperatures, for 24 hours, for the hardening elements to precipitate into the grains stucture making them exceedly strong or hard. The same applys to alloys tool steels, and other exotic iron based, or nickle based materials. These heat treating processes all have Time and Temperature curves for each alloy an exact formula for the heat treating or anealing, where the atomic structure transforms in its grain structure and recrystalizes. All of which is done at far below melting points, which is the misconception about the fire temp of the WTC, and the temperature at which anealing(removal of the heat treating) is done. In steel that begins at temperatures only a little hotter than your home oven.
The mechanics of your broken bolt and vibration is probably one of the vibration acting on what is called a stress riser in the metal, such as the shape corner of the head of the bolt and shaft, or the end cut of the threads. A stress riser is the weakest point or most vaunerable, and developes a stress crack, that propogates over time, until it finally sheers. Sometimes the stress riser is within the grains and a point where the metal was shaped and fractured the grain boundries during some shaping process. Thats the kind of thing we studied in metalury, all the mechanics of that failure process, which can be done from a bolt to a building collapse.
April 9, 2009
Read these posts Joker you may learn something.
Your windshield bolt got me thinking about the sheer strength of a bolt. Tensile strength is the force need to stretch a material lengthwise until it breaks, sheer strength it the force required perpendicular, to the length to sheer it sideways. Imagine the bolting system in the WTC. Even Jokers picutres show 3 beam segment bolted togather at the top and bottom, and laterally braced by the floor segments. These bolts were designed for vertical holding of the loads and swaying in the wind, so they probably had very high tensile strength bolts, like heattreated high carbon, or other added elements to make them strong and hard.
This also increases the sheer strength, which sheer normally is considered the sheer strength of static loads simply hanging. Not shock loads. If you have ever watched a punch press they sheer the metal in a very fast impact, and the material is well backed up, so it can not move or shift, consequently the entire impact load, is dedicated to sheering the material. In the WTC, the weight of the building downward provided complete backing and bracing of the material(the beams), and they could not move any appreciable amount, or fast enough, plus they are preloaded. If 2 football players on a line were pushing each other, the stonger will prevail, if one of the has a second player behind him holding and bracing him, what would that do? When the airplane hit, the beams preloaded and braced, with noplace to move, all the force was on the sheering of the bolts, just like a punch press.
Imagine bolting plates of 60.000 PSI steel togather, with 1" bolts on the corners of 100,000 psi tensile strength. Now imagine that you placed the holes leaving only 1/2" from the edge of the steel place. The vertical static load would be sufficient to all hold it togather. Impact that with a load perpenticular to vertical, and the weaked link will probably be the narrow span of material to the edge of the plate. The edge of teh plates would probably be first to sheer. Its not hard to see that when the plane hit, the airplane did not bounce off, it penitrated the building, and the pictures show the beams all were what sheered. You can clearly see 3 beam segments sheered off level in the picture at the blot line, meaning the first implace sheered the bolts and/or plates.
2 solid objects of that weight plus volocity crashing togather, the weakest link was the bolting system, had nothing to do with Aluminum vs steel, everyone watched it live Joker.
April 9, 2009
The planes hit with 4,000,000,000 joules of kinetic energy the equivelent of 1912 pounds of explosives. This is roughly the equivelent of getting hit with TWO GBU-15 Bombs. add into that fuel and you get more than the equivel of the OKC explosion. Its not strength but kinetic energy. You want to do math? If this had been a focused targetted .45cal bullet it would have peneterated approximately 215 454 feet of armor with that kinetic force.
April 9, 2009
Thanks Aquatank, Joker disappeared from the argument he started. I wish just one time someone who begins the same arguement could propose a step by step senerio of how their preposterous ideas were pulled off if true. None of them ever have an even basic understanding of metals, materials, or the mechanics of failure analysis. Joker comparing simple aluminum foil properties to that of structural aircraft framing is typical, and when given credible statitsics, comes up with a pile of other pictures of a Cesna.
I said I was done with this subject and got sucked in again, when will I learn?
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