WTC Towers: The Case For Controlled Demolition

Discussion in 'UK Motorcycles' started by schoenfeld.one, Mar 1, 2008.

  1. In this article we show that "top-down" controlled demolition
    accurately accounts for the collapse times of the World Trade Center
    towers. A top-down controlled demolition can be simply characterized
    as a "pancake collapse" of a building missing its support columns.
    This demolition profile requires that the support columns holding a
    floor be destroyed just before that floor is collided with by the
    upper falling masses. The net effect is a pancake-style collapse at
    near free fall speed.

    This model predicts a WTC 1 collapse time of 11.38 seconds, and a WTC
    2 collapse time of 9.48 seconds. Those times accurately match the
    seismographic data of those events.1 Refer to equations (1.9) and
    (1.10) for details.

    It should be noted that this model differs massively from the "natural
    pancake collapse" in that the geometrical composition of the structure
    is not considered (as it is physically destroyed). A natural pancake
    collapse features a diminishing velocity rapidly approaching rest due
    the resistance offered by the columns and surrounding "steel mesh".

    DEMOLITION MODEL

    A top-down controlled demolition of a building is considered as
    follows

    1. An initial block of j floors commences to free fall.

    2. The floor below the collapsing block has its support structures
    disabled just prior the collision with the block.

    3. The collapsing block merges with the momentarily levitating floor,
    increases in mass, decreases in velocity (but preserves momentum), and
    continues to free fall.

    4. If not at ground floor, goto step 2.


    Let j be the number of floors in the initial set of collapsing floors.
    Let N be the number of remaining floors to collapse.
    Let h be the average floor height.
    Let g be the gravitational field strength at ground-level.
    Let T be the total collapse time.

    Using the elementary motion equation

    distance = (initial velocity) * time + 1/2 * acceleration * time^2

    We solve for the time taken by the k'th floor to free fall the height
    of one floor

    [1.1] t_k=(-u_k+(u_k^2+2gh))/g

    where u_k is the initial velocity of the k'th collapsing floor.

    The total collapse time is the sum of the N individual free fall times

    [1.2] T = sum(k=0)^N (-u_k+(u_k^2+2gh))/g

    Now the mass of the k'th floor at the point of collapse is the mass of
    itself (m) plus the mass of all the floors collapsed before it (k-1)m
    plus the mass on the initial collapsing block jm.

    [1.3] m_k=m+(k-1)m+jm =(j+k)m

    If we let u_k denote the initial velocity of the k'th collapsing
    floor, the final velocity reached by that floor prior to collision
    with its below floor is

    [1.4] v_k=SQRT(u_k^2+2gh)


    which follows from the elementary equation of motion

    (final velocity)^2 = (initial velocity)^2 + 2 * (acceleration) *
    (distance)

    Conservation of momentum demands that the initial momentum of the k'th
    floor equal the final momemtum of the (k-1)'th floor.

    [1.5] m_k u_k = m_(k-1) v_(k-1)


    Substituting (1.3) and (1.4) into (1.5)
    [1.6] (j + k)m u_k= (j + k - 1)m SQRT(u_(k-1)^2+ 2gh)


    Solving for the initial velocity u_k

    [1.7] u_k=(j + k - 1)/(j + k) SQRT(u_(k-1)^2+2gh)


    Which is a recurrence equation with base value

    [1.8] u_0=0



    The WTC towers were 417 meters tall and had 110 floors. Tower 1 began
    collapsing on the 93rd floor. Making substitutions N=93, j=17 , g=9.8
    into (1.2) and (1.7) gives


    [1.9] WTC 1 Collapse Time = sum(k=0)^93 (-u_k+(u_k^2+74.28))/9.8 =
    11.38 sec
    where
    u_k=(16+ k)/(17+ k ) SQRT(u_(k-1)^2+74.28) ;/ u_0=0



    Tower 2 began collapsing on the 77th floor. Making substitutions N=77,
    j=33 , g=9.8 into (1.2) and (1.7) gives


    [1.10] WTC 2 Collapse Time =sum(k=0)^77 (-u_k+(u_k^2+74.28))/9.8 =
    9.48 sec
    Where
    u_k=(32+k)/(33+k) SQRT(u_(k-1)^2+74.28) ;/ u_0=0


    REFERENCES

    "Seismic Waves Generated By Aircraft Impacts and Building Collapses at
    World Trade Center ", http://www.ldeo.columbia.edu/LCSN/Eq/20010911_WTC/WTC_LDEO_KIM.pdf

    APPENDIX A: HASKELL SIMULATION PROGRAM

    This function returns the gravitational field strength in SI units.
    This function calculates the total time for a top-down demolition.
    Parameters:
    _H - the total height of building
    _N - the number of floors in building
    _J - the floor number which initiated the top-down cascade (the 0'th
    floor being the ground floor)


    Simulates a top-down demolition of WTC 1 in SI units.
    Simulates a top-down demolition of WTC 2 in SI units.
    By Herman Schoenfeld
     
    schoenfeld.one, Mar 1, 2008
    #1
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  2. schoenfeld.one

    TFK Guest

    But none of that egghead stuff explains how two of the biggest
    buildings in the world could be properly prepared for demolition,
    without anybody knowing.

    But let's not let common sense get in the way of a good conspiracy
    theory, right?

    TFK
     
    TFK, Mar 1, 2008
    #2
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  3. schoenfeld.one

    Blah Guest

    how to construct a tin foil hat...
     
    Blah, Mar 1, 2008
    #3
  4. schoenfeld.one

    Colin Wilson Guest

    But none of that egghead stuff explains how two of the biggest
    You mean the planned "maintenance" that shut down the buildings a
    couple of weeks prior to the main event ?
    I'm sure that wouldn't have given them enough time to plant thermite
    in all the right places...
     
    Colin Wilson, Mar 1, 2008
    #4
  5. schoenfeld.one

    Blah Guest

    it might take longer than 2 weeks to do 110 floors?
     
    Blah, Mar 1, 2008
    #5
  6. schoenfeld.one

    Vinnie S. Guest

    Never mind that. I heard it take more than a "couple weeks" to plan this stuff,
    and then there is the setup.

    This guy probably thinks the moon landings were fake.

    Vinnie S.
     
    Vinnie S., Mar 1, 2008
    #6
  7. schoenfeld.one

    Vandar Guest

    Never happened.
     
    Vandar, Mar 1, 2008
    #7
  8. schoenfeld.one

    Shant M Guest

    WE LANDED ON THE MOON???? Now I've heard it all....
     
    Shant M, Mar 1, 2008
    #8
  9. schoenfeld.one

    Vinnie S. Guest

    Vinnie S., Mar 1, 2008
    #9
  10. Just think that if this poster had put all this wasted energy towards
    something positive he'd probably be a millionaire!
     
    The old geezer, Mar 1, 2008
    #10
  11. schoenfeld.one

    954RR Guest

    Can you imagine the size of the crew that would take? Yeah, that many
    people could keep their mouths shut and let's not forget all the wiring it
    would take.
     
    954RR, Mar 1, 2008
    #11
  12. Easy, they got Elvis to do it at night between his shifts at Burger
    King.

    Problem solved.
     
    Kevin Gleeson, Mar 2, 2008
    #12
  13. in message :> But none of that egghead stuff explains how two of the biggest
    : > buildings in the world could be properly prepared for demolition,
    : > without anybody knowing.
    :
    : You mean the planned "maintenance" that shut down the buildings a
    : couple of weeks prior to the main event ?
    :
    Citation please.

    : > But let's not let common sense get in the way of a good conspiracy
    : > theory, right?
    :
    : I'm sure that wouldn't have given them enough time to plant thermite
    : in all the right places...
    :
     
    Erasmus Brown, Mar 2, 2008
    #13
  14. : wrote:
    : > In this article we show
    :
    : how to construct a tin foil hat...

    lol
     
    Erasmus Brown, Mar 2, 2008
    #14
  15. : In this article we show that "top-down" controlled demolition
    : accurately accounts for the collapse times of the World Trade Center
    : towers. A top-down controlled demolition can be simply characterized
    : as a "pancake collapse" of a building


    mmm....pancakes...
     
    Erasmus Brown, Mar 2, 2008
    #15
  16. schoenfeld.one

    mojo Guest

    Is this a new plot for a "Die Hard" movie?
     
    mojo, Mar 2, 2008
    #16
  17. schoenfeld.one

    Colin Wilson Guest

    : You mean the planned "maintenance" that shut down the buildings a
    I can't remember where I saw it originally, but there are mentions of
    it on sites such as:

    http://home.comcast.net/~plutarch/911.html

    -----
    As it happens, during the weekend before 9/11, at least, the buildings
    were closed for an extremely unusual 36-hour power down. According to
    Scott Forbes (see below) only on floors 47 to 50, and men in
    maintenance suits were seen entering the building that weekend,
    ostensibly to do a network "recabling".
    -----

    and...

    -----
    Scott Forbes, who worked in the south tower (the north one was hit
    first), described his observations and impressions on the Jack Blood
    radio show. He was not working on 9/11, because his company required
    him to make preparations for the unusual power-down on the weekend
    before 9/11. His company was informed of the power-down long before
    9/11.
    -----
     
    Colin Wilson, Mar 2, 2008
    #17
  18. schoenfeld.one

    theBZA Guest

    LIES! ALL LIES!
     
    theBZA, Mar 2, 2008
    #18
  19. Just fewer pricks, eh?
     
    Janitor of Lunacy, Mar 2, 2008
    #19
  20. schoenfeld.one

    Blah Guest

    **** me- here's a theory - perhaps they WERE actually recabling?
     
    Blah, Mar 3, 2008
    #20
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