LOX/Kerosene has a theoretical TNT equivalence of just under 200%, *if*
fully mixed. But that basically only happens in laboratory tests,
because there's no overlap in the liquid ranges of the two. Pour them
together in the field, the kerosene freezes, the LOX boils and splashes,
and the result is anything but fully mixed, twice-as-powerful-as-TNT
gelled explosive. This has been tested, extensively, forty or fifty
years ago. My references are in the other office, but the aptly-named
"Project PYRO" is the place to start looking.
For pad or flight failures involving mechanical mixing and delayed
ignition, e.g. an internal bulkhead failure, the maximum credible TNT
equivalence is 20% of the propellant in the compromised tanks. If the
ignition source is simultaneous with the initiation of mixing, e.g.
firing the range safety package, the maximum observed TNT equivalence is
about 0.5%.
The F9 has about 400 tons of propellant in the first-stage tanks, which
were ruptured and ignited externally. That's maybe 2 tons TNT
equivalence (plus lots of fire). If the 100 tons of upper stage
propellant premixed internally and then detonated, that would be 20 tons
TNT equivalence, but the mixing event should have left unambiguous signs
in the remote telemetry and we'd be halfway to root cause by now. If
the upper stage explosion was also externally initiated (by which I
include events internal to the airframe but external to the tanks), 0.5
tons TNT equivalence.
This seems credible with the video, and with the damage at LC40.
John Schilling
john.schilling@xxxxxxxxxxxxxx
(661) 718-0955
On 9/11/2016 5:22 PM, Randall Clague wrote:
It was a million pounds of propellant. It doesn't need a detonation to make a lot of noise. If it had been a detonation, given that it was half a kiloton and LOX/kerosene is more energetic than TNT, the strongback and the lightning towers would be gone.
-R
On Sunday, September 11, 2016, Ben Brockert <wikkit@xxxxxxxxx <mailto:wikkit@xxxxxxxxx>> wrote:
It's nice folksy rocketeer wisdom, but is there any real reason to
think there wasn't any detonation at all? That's a lot of fuel and
oxidizer in close proximity on fire, and a simple tank burst from
pressure doesn't make a sharp boom audible and shaking windows from
ten miles away.
And no, it wasn't a BLEVE.
I've also had a detonation on a test stand, and the test stand and
engine were still there. Detonations aren't magic, and it's possible
to have a small one.
On Sun, Sep 11, 2016 at 6:32 PM, Randall Clague <rclague@xxxxxxxxx
<javascript:;>> wrote:
> "If you go out to the test stand and the test stand is severely
damaged, you
> had a case burst. If you go out to the test stand and you can't
find the
> test stand, you had a detonation." --Dave Hall
>
>
> On Friday, September 2, 2016, Marcus D. Leech <mleech@xxxxxxxxxx
<javascript:;>> wrote:
>>
>> On 09/02/2016 05:01 AM, Aplin Alexander T wrote:
>>>
>>> Classification: UK OFFICIAL
>>>
>>> Handling Instruction: DISCLAIMER - this is a personal e-mail
and only
>>> represents the views of the sender
>>>
>>> FWIW, Elon Musk has tweeted to say it wasn't actually an
explosion (and
>>> that Dragon would have been able to save itself):
>>>
>>> "@scrappydog yes. This seems instant from a human perspective,
but it
>>> really a fast fire, not an explosion. Dragon would have been
fine."
>>> https://twitter.com/elonmusk/status/771479910778966016
<https://urldefense.proofpoint.com/v2/url?u=https-3A__twitter.com_elonmusk_status_771479910778966016&d=DQMFaQ&c=clK7kQUTWtAVEOVIgvi0NU5BOUHhpN0H8p7CSfnc_gI&r=rPTfWqtJdrL0Ber-yr0E_hSjRXuvJH6ZmQx03u8-2as&m=Y4cjyR_P0jd5gcwtWQ3zQYAPlrxcVcc5cOroeNy4wYw&s=cOh6ffmyv2fb4EsM6JZcRRLU8T2QWBGVFi1Um7eju44&e=>
>>>
>> There was a window-rattling kaboom or two. It was an
explosion, but what
>> it *WAS NOT* was a detonation.
>>
>> When you have a test-stand explosion you can tell the
difference between a
>> mere explosion, and a detonation easily. In the former case,
>> there'll be burnt, and perhaps mangled, wreckage. In the
latter, you
>> can no longer find the test-stand :) :)
>>
>>
>>>
>>>
>>> Alex Aplin
>>>
>>>
>>>
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>>> "If you are not the intended recipient, please remove it from
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>>> the email and centralenq@xxxxxxxxxxx <javascript:;>"
>>
>>
>>
>
