Transcript Document

Destruction
of the Twin Towers
1
Problem with NIST Report
• Describes what they claim happened up
until the beginning of “collapse,” which
then proceeded in a gravity-driven “piledriver” process (as opposed to the
“pancaking” FEMA postulated)
• Analyzing the destruction of the building
wasn’t part of their assignment
• THE PROBLEM is that the destruction
displayed too many features inconsistent
with a gravity-driven model.
2
WTC 1-2 Destruction Features
Core Obliteration
Massive 1000’ structure of crossbraced thick steel columns were
dismembered (North tower section
survived only temporarily)
3
WTC 1-2 Destruction Features
Perimeter Columns
3-column-3-floor assemblies connected by
welded/bolted spandrel plates
4
WTC 1-2 Destruction Features
Perimeter
Shredding
5
WTC 1-2 Destruction Features
Concrete Pulverization
Concrete was pulverized before it hit the
ground, as destruction progressed
6
WTC 1-2 Destruction Features
Explosive Mushrooming
Both towers exhibited this mushrooming effect,
expanding to many times the size of the tower
7
WTC 1-2 Destruction Features
Lateral
Ejection
Large pieces of the
structures were
thrown horizontally
long distances at
relatively high
velocities
8
WTC 1-2 Destruction Features
Early ejections
Dust and
debris are
ejected
before fall -South tower
top is only
tipping
9
WTC 1-2 Destruction Features
Squibs
Ejections of dust far
below destruction -pressure might be
distributed that far
down due to piledriver compression,
but where does the
dust come from?
10
WTC 1-2 Destruction Features
Destruction Above Impact Zone
Equal-time frames, angle changes from 1 to 2, not from 2 to
3, cessation of rotation violates conservation of angular
momentum, unless mass is being destroyed
11
WTC 1-2 Destruction Features
Speed of Fall
• Many different versions
– some (even 9/11 Commission) claiming 10 secs
– Jim Hoffman’s video timeline indicates 15 secs
http://911research.wtc7.net/wtc/evidence/timeline/videos.html
• Free-fall ~ 10 seconds
• Even 15 too fast for overcoming obstacles at each story:
– destruction of the structural integrity
– pulverization of the concrete in the floor slabs, and other nonmetallic objects
– acceleration of the remains outward or downward.
12
WTC 1-2 Destruction Features
Expanding Dust Clouds
Dust reached ground
10 seconds after start
Core “spire” still
standing, fell at 29
seconds
Cloud has reached out
700’
Speed: 700/20 = 35
feet/sec = 24 mph
13
WTC 1-2 Destruction Features
Long-lived Molten Steel
Hey, let’s forget about the molten steel for a minute 14
- just like NIST did -- and . . .
Let’s get technical !
Was there ENOUGH ENERGY available
1. for NIST’s “pile driver” to cause collapse?
2. to expand the large, fast dust clouds?
3. to throw heavy beams fast and far?
15
Forces and Momentum
Momentum Transfer Analysis of the
Collapse of the Upper Storeys of WTC 1
Dr. Gordon Ross, June 2006
http://www.journalof911studies.com/articles/Journal_5_PTransferRoss.pdf
16
Forces and Momentum
Basic idea
Previous momentum analyses treated
floors as individual items hanging in
space, instead of being interconnected,
with forces moving and distributing
through the structure below.
17
Forces and Momentum
What you need to know about . . .
Compression of Steel Columns
1. Elastic phase -- load increases to failure
load, at which point column is shortened
0.2% of its length; can recover (“bounce”)
2. Shortening phase -- failure load then
shortens column, up to 3% of its length
3. Buckling phase -- buckling points appear,
much less force needed to continue
4. Speed of propagation wave: 4500 m/sec
18
Forces and Momentum
What happens 1
• Top 16 stories of North Tower (as a chunk)
free-falls through a “disappeared” story
• Hits at 8.5 m/sec
• At that speed, it takes .013 sec to shorten
next story by 3% (to commence buckling)
• .013 sec is time for force to propagate
~60m, or 16 stories down, so all these are
“moving” and thus have momentum
19
Forces and (conserved) Momentum
What happens 2
• Now 16+1 stories falling, cuts speed from
8.5 to 8 m/sec . . . BUT
• The 16 stories below are also moving
slightly, and their combined momentum
slows the top chunk to about 5 m/sec
• This gives additional time for the
propagation wave to involve additional
floors
20
Forces and Momentum
... and after many detailed calculations
of kinetic and potential energy, elastic
and plastic strain energy, and concrete
pulverization energy...
21
Forces and Momentum
Energy Summary
22
Forces and Momentum
But that’s an underestimate
• Initial drop -- Assumption of unimpeded drop is
unrealistically favorable to continued collapse
• Elastic springback -- robs some kinetic energy
• Ejections -- mass is lost by material thrown
outside the tower perimeter, and energy required
to move that mass outward
• The “chunk” -- energy also absorbed by damage
sustained by lighter columns in “chunk”
• Other damage -- energy needed to sever
floor/column connections and destroy other
structural elements and floor contents
23
Forces and Momentum
Conclusion
The energy balance of the collapse moves into deficit during
the plastic shortening phase of the first impacted columns
showing that there would be insufficient energy available from
the released potential energy of the upper section to satisfy all
of the energy demands of the collision. The analysis shows
that despite the assumptions made in favor of collapse
continuation, vertical movement of the falling section would be
arrested prior to completion of the 3% shortening phase of the
impacted columns, and within 0.02 seconds after impact.
i.e., Collapse stops after 1 floor drop
24
2. Dust Cloud Expansion
The North Tower's Dust Cloud:
Analysis of Energy Requirements for the
Expansion of the Dust Cloud Following the
Collapse of 1 World Trade Center
Jim Hoffman, January 2004 (v. 3.1)
http://911research.wtc7.net/papers/dustvolume/volumev3_1.html
25
Dust Cloud Expansion
But before we get into the
expansion of the dust cloud,
what about all that dust?
26
Dust Cloud Expansion
Pulverization Energy
• Concrete in tower: 90,000 tons
• Pulverize concrete to ~2mm size: 1.5KWh/ton
http://www.b-i-m.de/public/ibac/mueller.htm
• Energy to pulverize to 2mm: 135,000 KWh
• But energy to pulverize inversely proportional to sqrt
of particle diameter, dust 0.06 mm (or less)
http://www.911-strike.com/powder.htm
• Sqrt 2 = 1.4, sqrt .06 = .24 --- factor of 6
• So dust creation requires ~ 6x135,000=800,000 Kwh
27
Dust Cloud Expansion
Pulverization Energy
• Somewhere between 135,000 and 800,000
KWh needed
• FEMA’s report: Tower 1 construction stored
more than 111,000 KWh potential energy
• So not enough energy to pulverize concrete
not as fine as observed, much less
distribute it in fast-moving large clouds
• But forget that. There’s more ....
28
Dust Cloud Expansion
Basic idea
The amount of thermal energy needed
to expand the North Tower dust cloud
as observed 30 seconds after collapse
is far greater than the gravitational
potential energy available from the
height and mass of the tower. How?
29
Dust Cloud Expansion
What can produce expansion?
1. expansion of gases due to heat
2. vaporization of liquids and solids
3. chemical reactions resulting in a
net increase in the number of
gaseous phase molecules
(since this last can only be due to explosives,
we’ll ignore it)
30
Dust Cloud Expansion
Analysis steps
1. Estimate cloud volume at given specific time
before diffusion occurs
2. Factor out mixed-in air to get volume of
particles of the contents originally in tower
3. Establish ratio of this to the original volume
-- i.e., the volume of the tower?
4. How much energy is needed to generate that
ratio of expansion for different levels of gasexpansion and liquid/solid vaporization?
31
Dust Cloud Expansion
The picture (30 seconds later)
The ref points
The cylinder:
Height: 200’
Radius: 800’
32
Dust Cloud Expansion
Parameters at 30 sec
• Cylinder volume: 402 million ft3
– ~1/4 is buildings, so dust = 300 million ft3
– assume 1/3 is mixed-in air (unlikely -- see
next slide) so conservative estimate of
Cloud Volume = 200 million ft3
• Speed of advance observed: 25 mph
33
Dust Cloud Expansion
Due to mixing/diffusion?
• 25 mph is too fast for advance to be diffusion
• Outside features of cloud were relatively
stable, not diffused by m/d
• Sinking sections replaced by clear air
• Reports of people being picked up and
carried by “solid” wall of hot dust
34
Dust Cloud Expansion
Expansion in 30 sec
• Tower volume:
1368’ x 207’ x 207’ = 58.6 million ft3
• Cloud volume: ~200 million ft3
• Expansion ratio: 3.41 (conservative)
35
Dust Cloud Expansion
1. Gas expansion by heat 1
• If pressure and amount (mass) stay the
same, volume is proportional to absolute
temperature (PV = nRT)
• If start temp was room temp (300oK), 3.4 x
that is 1020oK, an increase of 680o.
• Raising air that far requires 499,500 KWh
(remember: available energy = 111,000)
• But it gets worse . . .
36
Dust Cloud Expansion
1. Gas expansion by heat 2
• Such tiny dust particles (10-60 microns)
will reach temp equilibrium with
surrounding air very fast
• So you have to raise them 680o too
• The 90,000 tons of concrete dust would
require > 11 million KWh
• And if there’s water, it gets worse, but
we’ll skip that and treat water separately
37
Dust Cloud Expansion
2. Vaporization of water
• 3.4 expansion means 2.4 x tower volume
would be created steam: 2.4 x 58 million ft3
= 141 million ft3 = 4 billion liters
• Volume at 100oC: steam = 1680 x water
• So 2.4 million liters of water needed to
produce the entire cloud volume of steam
• Conversion would require > 1.5 million KWh
• Plumbing + concrete + people: not enough38
Dust Cloud Expansion
How much of which?
• Heating of gases: would require 780oC
– Ground level not that hot
– High heat apparent higher in cloud (next slide)
• Water-to-steam: requires too much water, needs
additional heat to get to 100oC first
• If combined: steam conversion would add to the
energy requirement of gas heating, additional
head needed for concrete dust
• Reduction? Early dust settling would reduce
needed heat, but cloud behavior contradicts that
39
Dust Cloud Expansion
High Temperatures
“Digital photographs and videos show a bright
afterglow with a locus near the center of the
cloud, commencing around 17 seconds after the
onset of the North Tower's collapse.
“Once the afterglow started, the cloud developed
large upwelling columns towering to over 600
feet, and the previously gray cloud appeared to
glow with a reddish hue.”
40
Dust Cloud Expansion
Summary: Energy Sources and Requirements
Conservative figures
41
Dust Cloud Expansion
Why conservative?
• They are based on an estimate of dust cloud
volume at a time long before the cloud stopped
growing.
• They use a liberal estimate of the contribution of
mixing to the volume (1/3).
• They ignore thermal losses due to radiation.
• They ignore the resistance to expansion due to
the inertia of the suspended materials, and
energy requirements to overcome it.
42
Dust Cloud Expansion
Conclusion
The massive discrepancy between the
gravitational energy available and the heat
energy needed to drive the expansion of
the dust cloud render the gravity
explanation for the collapse of the North
Tower (and similarly, the South Tower)
untenable.
43
3. Beam Ejection
9-11: What Fired 270 Tons Sideways?
Dr. Stefan Grossman
http://www.cloakanddagger.de/_Grossmann/270 tons/911_What_Fired_270_Tons_Sideways.htm
http://74.125.95.132/search?q=cache:ymdSfX_QysJ:www.cloakanddagger.de/_Grossmann/270 tons/911_What_Fired_270_Tons_Sideways.htm+concrete+tons+"twin+towers"+9/11
&hl=en&ct=clnk&cd=6&gl=ca
44
Beam Ejection
Photograph by Michael Rieger taken on 09/18/2001 in New York
http://www.photolibrary.fema.gov/photodata/original/3942.jpg
45
Beam Ejection
World Financial
Center 3
------- WTC1 side (270’)
------------------ WTC1core-to-WFC3 (694’?)
46
Beam Ejection
Parameters
• Building: WFC3 American Express
http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch7.htm
• Horizontal distance: 1/10 mile / 160 m
• Beam weight: 600,000 lbs
http://www.usatoday.com/news/gallery/terr921/contenttemplate5.htm
• Vertical distance (conservative): 325 m
– North Tower -- use top: 400 m
– WFC3 24th floor: 75 m
• Air resistance: negligible (heavy, spearlike)
47
Beam Ejection
Calculation
• fall time = sqrt (vert-distance / 1/2 gravity)
= sqrt (325 m / 4.8 m/sec2)
= 8.14 sec
• horizontal speed = horiz-distance / time
= 160 m / 8.14 sec
= 71.1 m/sec = 44.2 mph
• Force to accelerate 300 tons to 44 mph ??
48
So we got technical !
And guess what?
There was not ENOUGH ENERGY available
for any of these theories or observations:
1. NIST’s “pile driver” theory of collapse
2. expansion of the large, fast dust clouds
3. Heavy beams thrown far and fast
49
If gravity didn’t have what it takes,
What did?
50