Twin Towers Collapse mechanisms - Re-explained
The problem for me with the collapses is that the investigative team for the Twin Towers have came to the conclusion for the cause but not entirely the effects. They have indicated what was happening to the building like the changes of the exterior columns, but in neither of the Twin Towers did they pinpoint what specific failure caused floors the size of an acre to start falling down. It boils down to a 'first cause' issue. They came to that sort of conclusion with WTC #7, but not for the Twin Towers. Whether they can't or they don't want to is irrelevant to me, what is relevant to me is knowing what caused what I saw and can see in any video I watch of it.
Some preliminary comments:
1) First this is strictly Off Topic however it is a related issue since it sets one context in which Free Fall is often raised as an issue. So I will respond with an outline explanation.
(If anyone wants to request a separate thread the heading above will serve as OP title with this post as the new OP);
2) There are two conflated issues (or sets of issues) which are:
(a) Understanding how the collapse occurred as a structural mechanism; AND
(b) Whether or not the official explanations went far enough and/or were accurate. I will focus on the explanation of what actually happened - once we have some shared understanding we can, if we wish, discuss the sufficiency of official findings; AND
3) The issue of CD is often treated as if the collapse options were the dichotomy of "Natural" or "CD" mechanisms. That is not true. The two options are "Natural" alone OR "Natural plus CD assistance". With my usual comments about somewhat inappropriate use of the word "natural".
THEREFORE In explaining there are two choices to legitimately address the CD element - EITHER:
a) Include CD in the discussion from the outset; OR
b) Set it aside until the mechanisms are clear THEN address CD in that context.
I will try this by method "a)" - CD on the table from the start.
THEN 4) I intend to start from the big picture AND known facts - "drilling down" to such details as we need. So in direct contrast with the usual truth movement "argument" which starts from a detail which the proponent cannot explain and some false leaps to the conclusion "I cannot explain it >> THEREFORE CD >> THEREFORE you have to disprove it."
So the aim is "Explain the collapses which actually occurred allowing that CD
assistance could be one of the factors."
The collapses of WTC1 and WTC2 were similar so I will treat them as the same until we reach a stage where differentiation is necessary (probably on the issue of "tilt".)
These are the "big picture" facts which we should agree on - let me know if you don't.
The collapse sequence was:
1) Aircraft impact caused some initial damage and started fires;
2) Fires were essentially unfought;
3) A period of increasing damage followed;
4) The "Top Blocks" were seen to move and tilt UNTIL
5) The impact and fire damaged zone(s) could no longer support the Top Block(s);
6) Which dropped/fell
7) In a sequence which progressed to ground level (allowing for the debris heap.
CD is plausible at three points:
A) Anywhere before "3" with pre cutting to weaken the core;
B) Anywhere in the impact and fire zone during 1-2-3 & 4 either by pre-positioned devices OR by devices installed during the event. Both having some difficulties BUT the possibility remains on the table; AND
C) During "7)" - the progression. ( Whether or not CD was applied in "7" it had to be in addition to either of the two previous options - reasons should be or should become obvious.)
Now the two critical collapse mechanisms are:
X) The "initiation" mechanisms of stages 3 and 4; AND
Y) The "progression" mechanisms of stage 7.
The "initiation" mechanism was a cascade failure process. (Despite recent assertions against that on another thread.)
A "cascade failure" involves progressive and sequenced failures where each failure is partially or wholly caused by the preceding failure. Similar to but several orders more complicated than the toppling of a row of dominoes.
The big picture truth is that what held up the Top Block was a collection of columns. Two simple must be true facts follow:
1) The Top Block fell; THEREFORE
2) All the columns had failed.
So the key to understanding the overall mechanism
of the initiation stage is understanding why and how columns failed - both singly and in combination.
Whether they failed by "natural" process caused by impact damage and unfought fires OR there was assistance from CD doesn’t change the fact that all columns failed.
And it must have been a "cascade" - whether or not there was any CD in there to help - because:
j) It occurred over time - progressively - not all at once instantaneous; AND
k) With columns failing in sequence (whether by natural or CD processes) the processes of "load redistribution" must happen (also whether natural or CD) AND
..those two are the defining characteristics of a cascade failure - sequenced over time with each step triggering the next.
I'll leave it there for now - having set the groundwork for a more detailed explanation AND having legitimately left the CD option in the discussion.
The main issues we need to address in the next stage of explanation are:
p) How does any single column fail - what are the consequences;
q) How does any column fail given the interactions which must occur with nearby columns (and that is the really complicated bit
) THEN
r)How do these sequenced column failures progress to involve all of the columns;
s) Initially to the stage where there is not sufficient residual strength in the remaining columns to support the "Top Block at which point;
r) The Top Block falls causing all the remaining "surviving" columns to fail instantly.
Watch for a follow on post.
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