Chris, this second picture does not support your contention of fires being caused by the North Tower collapse either.
I think your contention that fires spread vertically in WTC 7 has problems also. The building was designed to prevent vertical spread and it seems to have worked. There were fires on floors 7,8, 9, 11, 12, and 13 but none on floor 10.
Except for the fact of exterior damage, and damage to the elevator shafts and electrical,
No way you can know how much damage or what conditons existed post collapse of the towers, you are making Fallacious unfounded assumptions, that are irrelevant, to the discussion.
You have no evidence of claim, no empirical data to back your assumptions.
From the Dr. Greening, Dr. Benson paper, Collapse of the twin towers what did and did not cause it.
"Velocity of Air Ejected from the Tower
An upper bound on area through which the air initially contained within every story gets
expelled (Fig. 3a) is Aw = 4ψahc, where 4ahc = area of one perimeter wall, a = 64 m = width
of the side of square cross section of tower, hc = 3.69 m = clear height of one story = distance
from the bottom of a story slab to the top of the underlying slab, and ψ = vent ratio = ratio
of unobstructed (open) area of the perimeter walls to their total area (ψ ≤ 1). The initial
mass of air within one story is ma = ρaa
2hc, where ρa = 1.225 kg/m3 = mass density of air at
atmospheric pressure and room temperature. Just outside the tower perimeter, the air jetting
out (Fig. 3a) must regain the atmospheric pressure as soon as it exits (White 1999, p.149), and
its temperature must be roughly equal to the initial temperature (this is a well-known general
feature of exhausts, e.g., from jet engines (White 1999, p.149) or pipes (Munson et al. 2006)).
So, the mass density of exiting air ρ ≈ ρa.
The time during which the top slab collapses onto the lower slab ≈ ∆t = hc/z˙ = time
during which the air is expelled out (which is only about 0.07 s for stories near the ground).
Conservation of the mass of air during the collapse of one story requires that ρAw(va∆t) = ρVa.
Solving this equation gives the average velocity of escaping air just outside the tower perimeter:
va =
Va
ψAw∆t
=
az˙
4ψhc
(7)
Since the velocity of the crushing front near the end of North Tower crush-down is, according
to the solution of Eq. (2), ˙z = 47.34 m/s (106 mph), the velocity of escaping air near the end
of crush-down is
va =
64m × 47.34m/s
4ψ × 3.69m
=
(
205m/s (459 mph or 0.60 Mach) for ψ = 1
340m/s (761 mph or 1.00 Mach) for ψ = 0.604 (8)
The vent ratio ψ (which is < 1) is hard to estimate. It surely varies from story to story, and
also during the crushing of one story. Its effective, or average, value could be much less than
1 (because some of the perimeter area is doubtless still obstructed early in the crushing of one
story, and because much of the air escapes only after the story height has been reduced greatly).
In spite of these uncertainties, it is clear that the exit air speed is of the order of 500 mph and
that its fluctuations must reach the speed of sound. This must, of course, create sonic booms,
which are easily mistaken for explosions (supersonic speeds are virtually impossible since the
venting would require an orifice shaped similarly to a convergent-divergent nozzle).
There are other phenomena that can cause va to differ from the estimate in Eq. (8). The
air pressure surely exhausts the load capacity of the floor slab for a few microseconds before
it is impacted by the layer of compacted debris. So, the floor slab must crack before the story
height is reduced to λh, and the air must begin to leak through the cracked floor slab into the
underlying story, thus increasing the air mass in that story. Obviously some air must also leak
into the ceiling which behaves as a porous layer of compacted gravel (it is impossible for the
ceiling and the floor to remain flat and leak no air since otherwise the air pressure would tend
to infinity as the ceiling impacts the floor).
All these complex inter-story interactions must cause rapid and large random fluctuations
of internal air pressure and exiting air velocity. On the average, however, what matters is the
simple fact that the air must, in one way or another, get expelled from each story of the tower
within a very short time interval, which is only 0.07 s near the end of crush-down of North"
The air compression effect, would prevent gypsum buildup,
In building 7 while allowing hot metal shards to enter.
I would like for you to put your own theories to experimental testing.
