There were a lot of things that contributed to the oversized bang of the Black Sea Fleet landing ship Nonocherkassk.
Carrying 320 122mm Grad rockets certainly contributed.⬇️
Is there a way we can estimate how big the bang was? The answer is "yes."
Weapon effect🧵
1/
Carrying 320 122mm Grad rockets certainly contributed.⬇️
Is there a way we can estimate how big the bang was? The answer is "yes."
Weapon effect🧵
1/
https://twitter.com/Capt_Navy/status/1739714250430398741
We have a know weapon effect at a known distance from the blast with which to work.
An occupied Crimea railway station 600 meters from the blast shows weapons blast effect consistent with 2-to-3 PSI.
2/
An occupied Crimea railway station 600 meters from the blast shows weapons blast effect consistent with 2-to-3 PSI.
2/
https://twitter.com/Tendar/status/1739511877443506632
You can find nuclear weapon blast overpressure charts easily with internet searches and eyeball the rail station damage to it⬇️
Some AFU military are reported Nonocherkassk's 500 ton cargo also had 4,400 artillery shells & something special, Shahed-136 drones.
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Some AFU military are reported Nonocherkassk's 500 ton cargo also had 4,400 artillery shells & something special, Shahed-136 drones.
3/
The Russians recently upgraded their Shaheds with 40 kg thermobaric warheads shown below.
A bunch of these in the Nonocherkassk's hold would certainly amp up the blast.
We don't have a drone number here, so I'll come back to down thread.
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A bunch of these in the Nonocherkassk's hold would certainly amp up the blast.
We don't have a drone number here, so I'll come back to down thread.
4/
https://twitter.com/front_ukrainian/status/1731343668940882013
A modern 152mm shell has 7.9 KN of TNT and it's propellent varies between 8.1 and 8.9 kg.
4,400 rounds of 152 mm is 34.76 metric tons of TNT and (high end) 39.16 metric tons of propellent.
Propellent won't have the brisance, AKA shattering capability, of a high explosive.
5/
4,400 rounds of 152 mm is 34.76 metric tons of TNT and (high end) 39.16 metric tons of propellent.
Propellent won't have the brisance, AKA shattering capability, of a high explosive.
5/
A 122mm Grad rocket has 21 kg of propellent and between 18 and 21 kg, rocket dependent.
So 6.7 metric tons of propellent for 320 rockets and up to 6.7 metric tons of HE-Frag warhead mass.
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researchgate.net/figure/mm-ungu…
So 6.7 metric tons of propellent for 320 rockets and up to 6.7 metric tons of HE-Frag warhead mass.
6/
researchgate.net/figure/mm-ungu…
Fragmentation warheads are 50% to 75% metal fragmentations, so I'll use 10.5 kg explosive for 3.35 metric tons for the blast high explosive energy mass.
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man.fas.org/dod-101/sys/la…
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man.fas.org/dod-101/sys/la…
When you look at this video at the 16 to 18 second mark, you see a lot of burning particles on the surface of the fireball.
These speckles on the surface of the fireball that are most likely burning shell and rocket propellent.
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These speckles on the surface of the fireball that are most likely burning shell and rocket propellent.
6/
https://twitter.com/maria_avdv/status/1739598511748903401
So to account for the lower brisance of shell and rocket propellent, I'll credit it with 80% the explosive mass of warhead high explosive.
Shell HE - 34.76 *
Rocket HE - 3.35 *
Shell propellent - 39.16 * 0.8 = 31.33*
Rocket Propellent - 6.7 * 0.8 = 5.36*
* mass in tons
7/
Shell HE - 34.76 *
Rocket HE - 3.35 *
Shell propellent - 39.16 * 0.8 = 31.33*
Rocket Propellent - 6.7 * 0.8 = 5.36*
* mass in tons
7/
We have a working number of 74.8 tons of TNT high explosive equivalent to punch into an online nuclear blast effect calculator app.
Since this one is in kilotons of TNT.
So divide 74.8 by 1000 to punch in 0.0748 and leave aside the Shaheds for now.
8/
nuclearweaponsedproj.mit.edu/nuclear-weapon…
Since this one is in kilotons of TNT.
So divide 74.8 by 1000 to punch in 0.0748 and leave aside the Shaheds for now.
8/
nuclearweaponsedproj.mit.edu/nuclear-weapon…
My first run on the app doesn't match the observed blast effect at the Feodosia railway station given the blown out window frames and the disabled electricals preventing the use of electric railway engines there, AKA at least 2 PSI.
9/
9/
This is where the Shaheds come in.
Assuming 400 Shahed-136's with 40 kg warheads with enhanced blast. We are looking at another 16,000 kg of mass with more blast energy than TNT.
I'll FUJI* it at ~1.5 times TNT for 24m tons of TNT
*frequently used judgemental estimate.
10/
Assuming 400 Shahed-136's with 40 kg warheads with enhanced blast. We are looking at another 16,000 kg of mass with more blast energy than TNT.
I'll FUJI* it at ~1.5 times TNT for 24m tons of TNT
*frequently used judgemental estimate.
10/
That works out to 0.0988 kilotons. I ran this TNT mass number through the blast calculator app with no change in results.
When I used 0.1 kilotons of TNT, 100 metric tons of TNT blast equivalent, I finally got this result that ~matched the Feodosia railway station.
11/
When I used 0.1 kilotons of TNT, 100 metric tons of TNT blast equivalent, I finally got this result that ~matched the Feodosia railway station.
11/
BLUF:
There weren't enough shell/rocket munitions to account blast damage seen in Feodosia
There must have been many hundreds of Shahed-136 drones in the Nonocherkassk when she was "Storm Shadowed."
She was used to move Shaheds in the same way USS Indianapolis was used...
12/
There weren't enough shell/rocket munitions to account blast damage seen in Feodosia
There must have been many hundreds of Shahed-136 drones in the Nonocherkassk when she was "Storm Shadowed."
She was used to move Shaheds in the same way USS Indianapolis was used...
12/
...to move the A-bomb in WW2, for security reasons.
RuAF security that AFU signals, cyber & human intelligence penetrated.
The lack of these Shaheds in Crimean launch sites will affect Russia's military plans to attack Osea & the Ukrainian power grid this winter.
13/13 End
RuAF security that AFU signals, cyber & human intelligence penetrated.
The lack of these Shaheds in Crimean launch sites will affect Russia's military plans to attack Osea & the Ukrainian power grid this winter.
13/13 End
14/13
P.S.
Osea = Odesa
P.S.
Osea = Odesa
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