[gumboot]

Killtown,

Not many people are left to discuss this with, are there? Now, I am going to summarise for you, in very simple language. Please try to understand everything I am saying here and take it on board.

Before I proceed I must repeat once again that the enormous number of variables make very difficult. Please go back and find my link to the NIST analysis of the UA175 fireball to see what I mean. The process to calculate how much fuel was used (as a simple model) was very complicated.

We have repeatedly told you this, yet in a valiant effort to help you out, a number of people have made their best efforts to produce very rough estimates for you. You should respect those efforts.

Now, bearing that in mind, let us proceed.

You appear to have three major contentions.

1) The size of the fireball
2) The size of the mushroom cloud
3) The colour of the mushroom cloud

Okay.

1) The size of the fireball

In post 1256 R.Mackey did some calculations based on a 1 second ignition time, the speed of impact as a speed of spread for the jet fuel, and an even spread from the wings in all directions.

This produced a maximum initial fireball size of 554m, which R.Mackey felt was probably a bit big - he assessed a likely size of 200m with an acceptable range of 50m - 500m.

Then in post 1318 you made an attempt to compare "7 football fields" with the B-52 explosion. I am not sure where you got "7 football fields" from - R.Mackey's maximum of 500m is slightly less than 5 football fields (an American Football field being 110m long, according to Wikipedia).

You concluded that the B-52 fireball was twice the wingspan of the aircraft, or the length of one football field. You later ammended this to a maximum of 1.5 football fields, or 165m.

I did my own frame-by-frame analysis and came up with a figure of 4x the B-52's wingspan at the point of maximum fireball width - or 225m. R.Mackey's maximum fireball size of 500m is only a little more than twice the size of the B-52 fireball - not 7x as you initially claimed.

You then compared the B-52 to the MOAB, based on a fireball 5 football fields across.

As I demonstrated, using maths, a MOAB would flatten an area about 5 football field lengths across its diameter. However, an accepted figure for destroying most buildings is 5psi overpressure. I would imagine the overpressure inside the fireball itself would be extensively larger than this.

Someone kindly posted a video of a high-speed camera capturing a FAE blast. You will note that the fireball never reached the manaquin, but the overpressure still blew the manaquin into pieces.

Thus your calculation of the MOAB's fireball appears to be inaccurate.

Huntsman then gave a fireball estimate size based on the conversion of the MOAB and of a 51,000lb (UA93 estimated fuel load) FAE to TNT. They were comaprative. He used your 550m MOAB fireball, which I believe is an incorrect measure, but never mind. From this Huntsman then added fuel splatter to produce a possible fireball diameter of 858m.

Lastly, in post 1380, I used the NIST study of the fireball from UA175 to estimate the fireball size of UA93 based on Huntsman's calculation of 51,000lbs (23,000kg) for 7500 gallons @ 6.8lbs per gallon. I calculated it for both 75% burn and 95% burn. Range was 306-331m.

Note, I did not do a calculation for you maximum 10,000 gallon amount, however I can quickly do it now.

10,000 gallon @ 6.84lbs (Jet-A) = 68,400lbs = 31,000kg = 23,250kg (75%) or 29,450kg (95%)

fireball volume = 20.3 million (75%) to 25.7 million (95%)

That gives us a fireball diameter range of 338m - 366m

Putting this all together we have the following fireball sizes:

50m = R.Mackey minimum based on fuel dispersal
200m = R.Mackey likely size based on fuel dispersal
306m = Gumboot minimum based on UA175 fireball
366m = Gumboot maximum based on UA175 fireball
500m = R.Mackey maximum based on fuel dispersal
858m = Hunstman maximum based on MOAB blast size and fuel dispersal

NOTE: Many of these calculations are for INITIAL BURN POINT! The fireball will further expand after this point.


Moving on.

2) The Size of the Mushroom Cloud

We will begin with your own calculation, based on the interpretation of Val's photograph. You calculated a plume size of 2200 feet (670m) assuming the cloud had come from the UA93 crash site.

In my first post on this thread I indicated I had calculated (using the same method as you) a maximum mushroom cloud width of 600m across.

Alphaba did a calculation for the Concorde crash and produced a conclusion of a comparative size mushroom cloud.

In post 291 Buckwheatjones presented the calculations of a nuclear engineer. His findings were that 500-600m was entirely plausible, and infact a mushroom cloud 1000m across was not unrealistic. This was based on 10,000 gallons of Jet Fuel. His maths is shown so we could easily calculate out the comparison for other amounts of jet fuel.

Starting at post 447, Arkan_Wolfshade did an excellent series of posts to calculate the size of the mushroom cloud, using primarily Google Earth and trig calculations (kindly confirmed by CurtC). He produced a final calculation of (I think) 526m for the mushroom cloud, in post 554.

Finally, in post 1380 I gave an example of an explosion in which the mushroom cloud was significantly larger than the original fireball. I compared these with the fireball ranges calculated in the same post to give a mushroom cloud range of 1100-1650m. Including my newly calculated fireball maximum for the larger fuel load, we have a possible realistic mushroom cloud range of 1100 - 1830m.

From these points:

1) The mushroom cloud in Val's photo has a size of about 530 - 670m, based on the range of calculations, and assuming the cloud originated near the crash site.
2) As demonstrated by calculations, a mushroom cloud as big as 1000m - 1800m would not be impossible for the crash of UA93.

Concluding:
3) The mushroom cloud is an entirely realistic size.


The last point:

3) The colour of the mushroom cloud

Repeatedly, throughout this thread, you gave been given examples of different aircrash smoke plumes and the varying colours. In addition, Huntsman has demonstrated, by personal experience, that the plume in Val's photo does not look like an ordnance plume. I have also provided photos of other hydrocarbon smoke plumes that resemble the UA93 plume in both colour and form.

I and others have repeatedly pointed out that the colour of the plume depends a lot on the light conditions and settings of the camera used to take the photograph. Gravy has demonstrated very well, using the WTC fires, that the colour of smoke can very enormously even for the SAME EVENT - thus emphasising the difference that can result PURELY from camera settings.

And lastly, Pardalis has demonstrated that the mushroom cloud from UA175 very much resembled the mushroom cloud from UA93 in both colour and formation.

Thus we can conclude:
1) The UA93 plume does not resemble an odnance blast in colour
2) The UA93 plume resembles a hydrocarbon plume in colour
3) The colour of smoke plumes can vary enormously dependant on conditions and the settings of the camera used


So, Killtown, to sum up your three key points, and our combined responses:

1) What is the size of the fireball
A)Between 50 and 858m across

2) The mushroom cloud is too big
A)The above range of fireballs can comfortable produce a mushroom cloud ~600m across or larger

3) The mushroom cloud is the wrong colour
A) The colour of the cloud in Val's photo is perfectly in keeping with the range of likely results based on the variables of ambient light and camera settings.

Please memorise these above points, Killtown, so we do not have to go over them again.

Now, do you have any OTHER concerns about Val's photo aside from the three listed above? If not, will you apologise to Val?

-Andrew

P.S. My apologies to anyone I failed to mention in my summary. I scanned through the 40 pages of the thread to look for the key calculations, but likely have missed many.

This also, of course, does not address the excellent contributions others have made in addressing Killtown's many flawed arguments.