----- Original Message -----
From: Eugene Tenenbaum
To: info@9-11Commission.gov ; Jamie.Gorelick@wilmerhale.com ; director@wwic.si.edu ; rben-veniste@mayerbrownrowe.com ; ffielding@wrf.com ; sladeg@prestongates.com ; jthompson@winston.com ; PZelikow@9-11Commission.gov ; CKojm@9-11Commission.gov ; DMarcus@9-11Commission.gov
Sent: Monday, July 19, 2004 4:50 AM
Subject: FEMA contradicts laws of physics in the WTC collapse Study!

Dear 9/11 Commissioner,

        Below is a very serious argument to verify the FEMA Study about the WTC collapse.  The Study seems to contradict laws of physics at victim relatives’ expense maybe in support to the war in Iraq or else you will be able to find out.

        It is just the beginning of a broader piece I intend to publish very soon.  If you do not verify it now, you will not be able to say latter that you did not know about it, because I intend to include in my publication a note informing that I sent you this fragment today.

        Sincerely, Eugene Tenenbaum

FEMA contradicts laws of physics in the WTC collapse Study!

By Eugene Tenenbaum, 3985 Gouverneur Av, #1B, Bronx, NY 10463, Copyright © 2004 Eugene Tenenbaum
Jul. 17, 2004

         The Federal Emergency Management Agency (or “FEMA”) misleadingly implies in its Study’s key conclusion (or “the FEMA conclusion” or “the conclusion”), about the WTC collapse, that the airplane impacts caused a decisive damage, and so purposely skips analyzing a) the faulty structural design, guarantying the towers to fall under any extensive fire, and b) the faulty design review and approval process that should have prevented it.

The conclusion in question is the last and underlined sentence of the following quotation from “World Trade Center Building Performance Study: Data Collection, Preliminary Observations, and Recommendations” FEMA 403 • September 2002 • Second Printing (or “FEMA Study” or “the Study”) available, e.g. at http://www.fema.gov/library/wtcstudy.shtm or else:

FEMA Study, Chapter (or “Ch.”) 2, pp. 2-31/32: “There are some important differences between the impact of the aircraft into WTC 2 and the impact into WTC 1. First, United Airlines Flight 175 was flying much faster, with an estimated speed of 590 mph, while American Airlines Flight 11 was flying at approximately 470 mph. The additional speed would have given the aircraft a greater ability to destroy portions of the structure. The zone of aircraft impact was skewed toward the southeast corner of WTC 2, while the zone of impact on WTC 1 was approximately centered on the building’s north face. The orientation of the core in WTC 2 was such that the aircraft debris would only have to travel 35 feet across the floor before it began to impact and damage elements of the core structure.  Finally, the zone of impact in WTC 2 was nearly 20 stories lower than that in WTC 1, so columns in this area were carrying substantially larger loads. It is possible, therefore, that structural damage to WTC 2 was more severe than that to WTC 1, partly explaining why WTC 2 collapsed more quickly than WTC 1.”

Apparently, it looks… almost logical, if not for two fundamental problems.  First, less important - as the airplane hit WTC 2 not perpendicularly, so only its speed’s component perpendicular to the WTC 2 face caused the damage, because the parallel component slide along the face, therefore the effective, damaging speed was less than 590 mph (it would be nice to have at least fifth grade’s observations, but maybe, because the Study contains only preliminary observations, so it does not rise above the fourth grade’s level)!

Second, essential - as WTC 2 was hit at 80^th Floor twice as low from the roof than WTC 1 was at 96^th Floor, and there were 30 floors above the WTC 2 zone of impact (or “zone”), but only 15 floors above the WTC 1 zone, and so internal core (or “core”) columns at 80^th Floor carried load twice of a load at 96^th Floor, and exterior columns in the WTC 2 zone carried roughly 20 % more of a building weight load then in the WTC 1 zone, but additionally strength added to exterior columns against wind pressure load 30 floors below the roof was roughly four times that added only 15 floors below the roof, so exterior tubular columns in the WTC 2 zone had roughly two and a quarter more of strength than in the WTC 1 zone, and internal core corner column in front of the WTC 2 airplane nose had four times more of total strength than the mid-side core outer column in front of the WTC 1 airplane nose.  There was no wind nor column wind load on the 9/11.

Therefore, the structural damage to WTC 2 was LESS severe than that to WTC1 on the contrary to the FEMA conclusion, because the columns in the WTC 2 zone had double-quadruple of a strength of WTC 1’s, but the WTC 2 airplane speed was only 26 % greater, and its kinetic (destructive) energy only 58% greater than the WTC 1 airplane, so much less than the double-quadruple strength and mass advantage.  In other words, the advantage of WTC 2 zone column strength over WTC 1’s was much greater than the advantage of the WTC 2 airplane destructive energy over WTC 1’s.

That observation is so simple and obvious that the cited above FEMA staggeringly false conclusion is difficult to explain by a mistake.  So, who decided to make it?  Any idea why?  Could the intended war against Iraq play a role?  Would the possibility of a faulty WTC design contributing to or even causing its collapse have deterred the public opinion from supporting the war the Administration had afraid of?  You are invited to answer these questions.

To see, how obviously the FEMA conclusion is wrong (if you forget from school), as well as to show it to five-year-old children, just borrow any blocks from them, build a column by stocking a few blocks vertically (one on another) and hit the column in the middle, so it collapses.  Next build again the same column, put your hand on the top of it, press the hand down, and try to collapse the column by hitting like before.  It is impossible, if you pressed strong enough!

“Greater load representing greater strength and resistance to damage” can be recognized in every kindergarten, but not in FEMA despite that actual FEMA Study’s Figures 2-27 and 2-16, as well as the similar Damage Area figures below, CLEARLY show that the structural damage to the exterior columns of WTC 2 was (34 %) smaller by area than of WTC 1, illustrating that simple law of physics at work.

The actual damage areas to WTC 1 and WTC 2 exterior columns were 1,607 and 1,044 square feet respectively!  Following the pattern, the structural damage to internal columns of WTC 2 should have been also LESS severe than in WTC 1 opposite to the FEMA conclusion.

FEMA - of course - could defend its conclusion claming using the word "possible", but it implies the greater chance of only two possible (much greater or smaller), as meant chance "that structural damage to WTC 2 was more severe". To describe as possible a minuscule chance qualifies as MISREPRESENTATION, e.g. if a chance of a less severe structural damage to WTC 2 was 99.999 %, so the more severe damage to it was still possible (with probability of just 0.001 %), so technically FEMA Study's report was (always) true, but with the reasonable doubts of 99.999 %!

Maybe “incompetent” authors wrote FEMA Study in a good faith?  Their omission from the inner core (or “core”) in the WTC 2 plan at the zone of aircraft impact of the massive box columns - which greater strength contradicts their conclusion - rather suggests a self-serving misrepresentation.

The misrepresented outer columns of the core at 84^th Floor and below (within the zone of impact in WTC 2, but not in WTC 1’s) were significantly heavier boxes 36x14-16 inches made of ¾- 4-inch plates (FEMA Study, p. B-2) than the actually drawn I-shaped inner core’s outer columns in the WTC 1 zone of impact.  Figure B-6 of FEMA Study shows an imprint of the I-shaped column on the heavier box column illustrating the huge difference between them.

The massive boxes can be seen on photographs,

and in a WTC tower typical floor plan

available at http://www.greatbuildings.com/cgi-bin/gbc-drawing.cgi/World_Trade_Center.html/World_Trade_Tower.gbd; unlike in the following plans used by FEMA Study (Figure 2-1) indicating the huge structural differences between the inner cores in the zones of aircraft impacts below 84^th Floor in WTC 2 and way above 84^th Floor in WTC 1.

Not showing in the FEMA Study (Figure 2-25) the massive columns in the WTC 2 impact zone has been misleading, self-serving and unethical.

One of Achilles’ heel were the “walls” of tower inner cores that unfortunately were just plain and not reinforced sheetrock (gypsum board) partitions with strength comparable to heavy cardboard, and completely vulnerable to the slightly elevated pressure of even a foot kick, hence also to an impact of the actual jet fuel fireballs, or, e.g. a propane gas blast, like in “Backdraft” (1991) film.  So, it seems to be misrepresenting and self-serving the following (underlined) FEMA Study reasoning from p. 2-15 unsubstantially insinuating that wracking of the week and flimsy partitions (also ceiling panels) at WTC 1 indicate structural damage (i.e. to the columns): “They [witnesses] described extensive building debris in the eastern portion of the central core, preventing their access to the easternmost exit stairway. This suggests the possibility of immediate partial collapse of framing in the central core. These persons also described the presence of debris from collapsed partition walls from upper floors in stairways located further to the west, suggesting the possibility of some structural damage in the northwestern portion of the core framing as well.

Unfortunately, the destruction of flimsy core partitions deprived the stairwells and (elevator) shafts of their enclosure turning them into chimneys and the towers into stacks helping the fires to spread heating bigger floor areas, of which thermal expansion faster collapsed the towers, but not necessarily increased fire temperature.  The issue of partitions is irrelevant for the structural analysis except for widening the fires, heat distribution and subsequent thermal expansion speeding up the collapse (increasing casualties), but not changing the mechanism.

To find out, why the towers collapsed so differently, and so to analyze differences between the both airplanes impacts, it is useful to visualize the both zones of aircraft impact on one plan with the correct massive columns only on the WTC 2 side of impact (one plan’s half) and not on the WTC 1 side (other plan’s half), and showing the difference between them (in reality they were present or not at once on both sides), and disregarding the flimsy partition.  One plan can show also both areas of damage to the exterior columns, both airplanes at their angles of impact and at the positions of slowing down, where they were not able to inflict any further damage to the exterior columns stronger than the airplanes’ soft bodies, when the surviving exterior columns begun damaging airplanes wing ends.  Such plan shows also the trajectories of both airplane landing gears and engine found penetrating through the entire floors, and landing far outside the towers.

The key question is, if the airplanes caused damage to inner core columns, and, if yes, to what extend.

Let’s first start from an obviously false following statement from p. 2-16 of FEMA Study claiming that debris, which passed through the towers [almost intact!], “doubtlessly” caused damage to core columns, and that the extend of this damage cannot be known (underlined):  It is known that some debris from the aircraft traveled completely through the structure. For example, […]. Part of the landing gear from this aircraft was found at the corner of West and Rector Streets, some five blocks south of the WTC complex (Figure 2-18). As this debris passed through the building, it doubtless caused some level of damage to the structure across the floor plate, including, potentially, interior framing, core columns, framing at the east, south, and west walls, and the floors themselves. The exact extent of this damage will likely never be known with certainty.

First – the phrase “some level of damage” is MANIPULATIVE and MISLEADING, because it includes a near zero level of damage, so technically FEMA is right in any case, because that phrase means that there was or was not damage, i.e. it is truism meaning some level from near 0 to 100 %!

Second – the debris, which passed completely through the towers almost intact keeping their initial trajectories, certainly could not have caused any damage to core columns, because it was virtually impossible to strongly hit a column certainly causing a bounce in a different direction, and then come back to the original trajectory requiring – improbable - another bounce in the exactly opposite direction, and all that at 200 mph and without even a significant damage

to the passing engine, which was extremely fragile, or landing gear!  So, the opposite of the above FEMA claim is true that the debris, which passed through the towers [almost intact and not changing their initial trajectories], certainly did not cause any structural damage to the towers.  So, their free fall can be used to determine their speed of passing through the cores after the initial airplane impacts on the exterior walls.  And that is a critical conclusion FEMA avoided at all cost.

Third – damage to core columns, if any, could have been causes by debris, which did not pass through the towers – unlike in the above FEMA statement.

Fourth – once the speed of debris passing through the cores is known, it is possible to model the exact extend of damage [to core columns] with a high degree of certainty opposite to the FEMA insinuation underlined just above.  If the speed was low, because of the enormous strength of the exterior walls absorbing a vast majority of the initial impact energy, it is possible to exclude any significant damage at all, and opposite to FEMA Study.  The passing debris issue is critical!

It is obvious that the airplanes entering the towers were constantly loosing speed.  The floor plan above shows the positions of both airplanes fully filling the damage holes in the exterior walls between the intact exterior columns on both sides of the damage areas shown above and on Figures 2-27 and 2-16 of FEMA Study.  At these positions the airplanes lost so much of their initial speeds that their movement was too slow to cause any further damage to the hard steel exterior columns by their soft aluminum bodies, and the intact exterior columns on both sides of the damage areas started to cut out the airplane wing ends exceeding the damage areas perimeters.

Knowing parameters of the exterior columns and whole towers, wings and Boeing airplanes (they were designed and tested in the computer), it is easily and cheaply to simulate the impacts in the computer, and to get these speeds, but FEMA failed to do so.  Why?  There were successful Flight 800 or shuttle Columbia crash recreation efforts.

Instead, FEMA Study (p. 2-22) provides, e.g. a useless number of gigawatts of energy were released by both fires, or misleadingly speculates about temperature allegedly reaching 1,400 °C melting point of steel (p. A-12, 17) implying such a possibility.  FEMA Study provides references to the very outdated office fire experiments in 1972 (p. A-3), but DOES NOT conduct any computer simulation of the actual WTC fires, like – though maybe not perfect - the MSC Marc simulation (http://members.fortunecity.com/911/wtc/wtc-microsoft.htm).

The MSC Marc simulation is useful allowing to conclude that “It is clear that the fires could not/did not get much above 825°C (and were almost certainly cooler)” and also to ask “what caused the fire sprinkler system to fail within a few minutes of the impact”, though the included there Boeing 747 collision simulation is out of touch with a WTC reality, because the 767s were less than a half weight of a 747, and the WTC tower structure nor the 767s’ speed were not reflected.

Coming back to the floor plan above showing the airplane positions inside the towers, at which they were too slow to inflict any structural damage to both - the exterior columns and stronger inner core columns, the question remains, if airplane debris reaching these positions could have damaged the inner core columns within the front of both airplanes shown on the plan above.

There are four (4) inner core columns within the front of both airplanes.  Because both airplanes shattered on impact and the front section of the WTC 1 airplane could not survive to reach the inner pair of columns of the inner core, so further considerations are limited only to the outer pair of columns of the inner core of WTC 1.  Because of a greater load and strength of columns at the zone of airplane impact in WTC 2 than in WTC 1 (indicated by the smaller area of damage to exterior columns), it is certain that during the impacts the WTC 2 airplane was slowing down more rapidly than the WTC 1 airplane, and its front was damaged more than of WTC 1’s, hence the two (2) furthest inner core box columns within the front of the WTC 2 airplane can be excluded from a damage consideration.

The almost equal distances from the towers of the fallen almost intact airplane parts after completely penetrating the towers prove that the WTC 2 airplane was slowed down on impact more than the WTC 1 airplane.  The schematic here (FEMA Study Figure 1-3) shows the areas of landing of the airplane debris after flying over the whole floors and falling down far beyond of the opposite tower sides to the impact sides of the towers.

Landing gears of both airplanes completely penetrated both towers.  The WTC 2 landing gear (wheel) fell 1212 ft (370 m) from WTC 2, and the WTC 1 one – 1310 ft (399 m) from WTC 1.  The WTC 2 zone of impact was 994 ft (303 m) above the ground, and the WTC 1 zone – 1178 ft (359 m).  There is a simple formula – on approx. seventh grade level - to calculate speed of projectile at constant downward acceleration (www.physics.rutgers.edu/ugrad/123/lab/M04-Projectile_rev.doc) - in our case – of 32 ft/s² (9.8 m/s²) caused by the gravity force, if disregarding air resistance on falling body that shortens distance of falling: velocity=(distance of projectile fall)*{[(constant downward acceleration)/[(height of fall)*2]}^1/2.

That simple formula (without considering air resistance) allowed calculating the speeds of the landing gears exiting WTC 2 and WTC 1 at 105.3 and 104.3 mph respectively.  The actual speeds were higher, but also almost identical, because of similar air resistance.  Air resistance (drag) is a product of air density (1.225 kg/m^3), silhouette area A of body (its area as seen from the front), dimensionless constant C called the drag coefficient (that depends on the shape of body), and squared velocity of body divided by doubled mass of body.  (Projectile motion with air resistance description can be found, e.g. at http://wps.aw.com/wps/media/objects/877/898586/topics/topic01.pdf, and its programming – at http://www.nyu.edu/classes/rosenberg/AirResistance.html.)

Calculating speeds of the landing gears exiting WTC 2 and WTC 1 with air resistance, two cases were considered.  First: gear mass m=150 kg, wheel height of 1.2 m, wheel width of 0.4 m, so area A=0.48 m^2, drag coefficient C=0.5.  Second: m=200kg, A=0.6 m^2, C=1.0.  In the first case (m=150kg, A=0.48 m^2, C=0.5) the EXIT floor speeds of the landing gears from WTC 2 and WTC 1 were 122.4 and 123 mph respectively, and the preceding ENTRY floor higher speeds - needed to travel through the whole 210 ft (64 m) span of each tower floor after the impact (from initial impact exterior wall to exit window), and leaving at the previously calculated EXIT speeds - were 130.2 and 130.9 mph respectively.  In the second, conservative case (m=200 kg, A=0.6 m^2, C=1.0) the EXIT from WTC 2 and WTC 1 speeds were 139.8 and 143.2 mph, and the floor ENTRY floor speeds were 156.6 and 160.4 mph, respectively.

Recordings and a simulation (http://realex.nist.gov/WTCanimation2.ram) show that after the initial airplane impact the resulting fireball expanded through the tower - like a very strong hurricane (much over 100 mph) - ripping off panels of elevation falling down beneath flames, so also leveling everything inside, but columns, and leaving no obstacles slowing down the landing gears and engine traveling through the towers within that fireball hurricane.

Even, if adding a bounce or two from the floor inside the towers not much changing trajectory, but increasing the landing gears speed from the calculated 160 mph without bounces to around 200 mph with bounces, the plans still lost more than 50 % of their initial speeds on the initial impacts with exterior columns, so more than 75% of their destructive (kinetic) energy (proportional to velocity squared v^2 and mass m, so when velocity drops by 1/2, energy drops by ¾ to 1/4, because [1/2]^2=1/4), so the airplane destructive power to damage inner core columns decreased at least four (4!) times after the initial impacts, FEMA Study ignores and MISREPRESENTS on p. 2-16 claiming that “The exact extent of this damage will likely never be known with certainty” manipulatively implying that some damage had to occur and nothing can be done, because its exact extend cannot be known with certainty, and that is necessary to solve the mechanism of the collapse, and anything else is not good enough, and so it is appropriate not even attempt to assess the damage, nor to conduct a structural analysis based on probabilities, nor to consider more than one possibility, nor to consider that no significant damage to the columns could have happened at all at 200 mph most likely, i.e. that it is fine to refrain from further considerations, and it is the only way to proceed, because there is “no smoking gun”.

The “no smoking gun” theory excusing from an effort, if problems were difficult, does not apply to positions including a full responsibility for dealing with the problems especially, if someone else could have sat down for a half of year and solve them.  The use of the “no smoking gun” excuse and not even attempting solving problems by those, who are responsible, proves their incompetence or worse.  Before using it, look in your job description and think twice before claiming the “no smoking gun” excuse!  A “smoking gun” is not served on a silver platter.  It grows and becomes more visible while you work intelligently to solve a problem, and elements without an apparent meaning or connection start to build a whole picture, and a smoking gun emerges becoming more visible step by step.

The exterior columns slowed down the WTC 2 airplane impacting at 590 mph more than the exterior columns slowed the WTC 1 airplane impacting at 470mph with only 63 % of the kinetic energy of the WTC 2 airplane, to almost identical landing gear exit speeds.  Additionally, the debris passing entirely through WTC 2 did not go through the inner core unlike in WTC 1, but near the core, so on the debris path were no columns to bounce from slowing WTC2 debris down unlike in WTC  1.  It means that the landing gear passing entirely through WTC 1 did not bounced as well, because, if it had retaining on exit the same speed as the WTC 2 debris without bouncing, the speed of debris in WTC 1 would have been actually greater than in WTC 2 rendering the FEMA conclusion just plain insane.  The fact that the exit speeds were almost identical clearly indicates that the WTC 2 exterior columns were much stronger and resistant to damage than the columns of WTC 1, as they supposed to be, because of their greater load.  By the same principal, the WTC 2 zone of impact inner core columns were much stronger than of WTC 1.  So, after passing the exterior columns with similar speeds in both towers, the airplane debris could not damage the much stronger inner columns of WTC 2 more than those of WTC1 with 100% certainty and contrary to the FEMA conclusion!

The fall of the WTC 2 airplane engine not much farther from the landing gear fall indicates that the landing gear was not slowed down much inside the tower, because the gear behind the engine in the airplane impacted a moment latter at a slightly lower speed of the slowing down by the impact airplane while the slimmer engine was still rotating.  This points to the initial impact, as the separation event that did not distort much the trajectories, but certainly trashed the wings slightly rotating them back, separated the engines pushing their trajectories slightly outward, and also had to free the landing gears leaving not much of the airplane front fuselages as a whole, which had to further slow down plowing through the concrete (which doubled its strength after 30 years) of the floor(s) in order to reach the inner core columns to damage them.  So, the exit speeds of the debris passing entirely through the towers are certain indicators that the initial impacts slowed down the airplanes by more than a half of their initial speeds.  So, it seems like FEMA purposely neglected to conduct computer simulations of the initial impacts to avoid reaching a right conclusion!

Watching bad airplane accidents at landings, it is apparent that they are very fragile and brake on impact with hard surfaces at landing speeds.  So, both airplanes hitting the towers at maximum speeds were disintegrating on initial impact.  The superimposed airplane profiles not fitting well the exterior structural damage areas clearly indicate shifts of airplane parts hitting the towers latter (farther back in the airplane) from their initial location within the profiles.  These shifts could have been only caused by airplane deformation resulting from the disintegration on the initial impacts.  E.g. just after the initial moment of impact the airplane wings started to roll up causing the damage above their initial positions, as indicated above by the damage to the exterior columns above the superimposed airplane profiles, etc.

The airplane disintegration on initial impact is supported by the fall of the WTC 2 airplane engine slightly further than of the same airplane’s landing gear, because the engine - more up front than the landing gear - hit the tower, separated from the airplane earlier, and at a slightly higher airplane’s speed (decreasing on impact) than the landing gear impacting a moment latter at a slightly lower speed.  Only a small deviation of the WTC 2 part trajectories from that airplane direction before impact also points to the airplanes disintegration on the initial impacts despite that the WTC 1 airplane landing gear probably slightly bounced from a column deviating from the airplane trajectory before exiting the tower.

Disintegration on the initial impact means that resulting separated airplane pieces lacked significant energy to exert damaging pressure on inner core columns protected by their load and strength much greater than exterior columns of the same floor.  The flying pieces (except the hard engine shafts, as Peter Bressington of Ove Arup & Partners, Consulting Engineers explained showing a simulation at 33 min. of Inventions, Building to Extremes show on PBS) did not have energy to structurally damage the inner core columns contrary to the FEMA conclusion.  FEMA chose not to conduct cheap computer impact simulations maybe to avoid pointing toward revealing tower design inadequacies reducing reasons to go to war with Iraq, but at the expense of orphans and widows.