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Anonymous
/r/ing some high res Katamari Damacy pics.
In return, cannon fire?
>> Anonymous
bump
>> Anonymous
>>176033

what makes me wonder is that the navy people have their ears covered while the civilians don't
>> Anonymous
>>176705
They want to be able to hear when they're 60? Civilians only witness the bang a couple of times, while the navy people probably do it on a daily/weekly/monthly basis for years.
>> Anonymous
>>176730
I suspect it would only take one bang to permanently impact hearing
>> Anonymous
I'm guessing those are 16"/50 (40.6 cm) Mark 7 cannon firing. This round creates overpressures exceeding 50 psi (3.5 kg/cm2) close to the muzzle and 7 psi (0.5 kg/cm2) at a distance of 50 feet (15 m) from the muzzle. Overpressure is associated with ear and lung damage from fast-rising, long duration pressure pulses. If it were a slow rising pulse the body can equalize, as in scuba-diving. If it were short duration the parts could stand greater stress. You won't die from eardrum rupture, but it does reduce your abiltiies! 5 Pounds per Square Inch is where eardrum rupture starts. There is a great deal of variation in suscetabilty to damage. The very old are most susceptable. 50% of population rupture occurs at around 15-20 PSI for over 20 years old and around 30-35 PSI for under 20 years old. Again, there is a wide individual variance here. Also, some eardrum will spontaneously heal with only slight or partial hearing loss. Lung damage begins at 12 (8-15) PSI. Severe lung damage occurs at 25 (20-30) PSI. Lethality begins at 40 (30-50) PSI, 50% lethal at 62 (50-75) PSI and 100% lethal 92 (75-115) PSI.
For the demonstration it's possible that a light round was used, but the blast can be clearly seen modulating the atmosphere in a manner which would indicate considerable hazard without appropriate protection.
>> Anonymous
no pics..but before the end of the year, i should be attending OCS. i'm pretty excited about it.
>> Alister
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>> Alister
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>> Alister
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All I have, sorry.
>> Anonymous
>>176998
Wait a minute...

How can something be 50% lethal???
>> Alister
>>177036
Well, in terms of say, LD50 numbers, it would be the amount necessary to be lethal to 50% of the population. Same principle, I guess.
>> Anonymous
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>> Anonymous
>>177067
To give a sense of scale...Dimensions: 887' (length overall); 108' 2" (maximum beam)