Could you survive standing on the SpaceX barge if the Falcon 9 tipped over?

[PTNLemay]

I'm sure we've all seen the videos, the Falcon 9 lands on the barge, everything seems fine, but a landing leg was forced just a bit too hard and the whole thing tips over.  Even though there's relatively little fuel left in it, it still manages to explode into an impressive fireball.  

How big a blast is it though?   Say you were unlucky enough to be on the barge shortly after the rocket landed (say it's your job to strap it down for the return trip) and it starts to tip over.   I remember from this YouTube video that in such a situation (where you're facing an explosion near you) jumping into the water might actually be a really BAD idea because it's an incompressible fluid.  

So you crouch down and cover your hears?  Could you survive?    Wikipedia says the drone ship is 300 feet long, so assuming the rocket landed near the middle, the furthest you could get away from it without falling into the water would be around 150 feet.  Now we need to know the approximate amount of joules that go off when it explodes.

I wasn't able to find the KJ per KG for rocket-grade kerosene, but aviation-grade has ~46 KJ per KG.   For comparison, 1 KG of TNT has 4 megajoules.

So yeah... discuss.

Edited May 9, 2016 by PTNLemay

[SmartS=true]

Not sure if you would survive, but you would probably go deaf and might get burned.

[RainDreamer]

Jumping into the water is dangerous, IF the explosion is in, or very near the water surface due to shockwaves that will absolutely crush you.

In this case though, jumping in the water, with the whole barge itself between you and the explosion, might be a better idea.

If it tips over and fall into water before exploding, then maybe staying on the barge as far as possible from it, hold on tight on some thing and lay down flat, because the barge is going to be thrown around.

Edited May 9, 2016 by RainDreamer

[kerbiloid]

2 hours ago, PTNLemay said:

but aviation-grade has ~46 KJ per KG

MJ, not KJ. TNT is much weaker than fuel, it just releases its energy at once.

In case of Falcon we probably don't have an explosion (as in vacuum bomb), but just a fast burning. So, more temperature effects than a shockwave.
Also a mighty blow into the deck, causing strong vibratory inputs which can damage the observer's organism.

Btw, just remembered a casus from 1904 Russian-vs-Japan war memoirs.
A midshipman stayed on board of a damaged warship to blow it up. After preparing all stuff he had made a rope cradle - hanging from a pole, above the ocean, below the deck level,
After he had ignited the delay cords, he took his place in the cradle  and happily survived the ship explosion.

Edited May 9, 2016 by kerbiloid

[MeticulousMitch]

If we're only considering overpressure from the blast, then it would certainly be survivable, though perhaps with ruptured eardrums. In an uncontrolled rocket failure the combustion is fairly slow, more like a fire than an explosion. This much can be seen from the intact engine cluster:

at 150 feet even a 1-ton charge of TNT produces insufficient overpressure to cause lung damage, and that kind of blast would obliterate the engine cluster.

(adapted from http://dtic.mil/cgi-bin/GetTRDoc?AD=ADA286212)

radiant heat is probably not a grave concern as the fireball is confined to the centre of the barge and only lasts a couple seconds.

I would be far more concerned about flying debris at that range, so while you may be OK at the edge of the barge, diving underwater would be a safer option.

 

 

[Streetwind]

Yes, you could absolutely survive this. Neither heat nor shock nor flying debris will kill you. You won't even suffer an injury.

The reason is simple: the droneships have heavy-duty blast walls that separate the landing pad from the eqipment containers on either end of the barge. You would simply take cover behind one of them.

 

For the question of whether you would survive if you were on the landing pad itself... well. I'd say that, assuming the rocket didn't hit you directly, you'd suffer injuries from the heat. The deflagration may only last a few seconds, but the metal wreckage may take a minute or two to stop glowing, and the small heap of organic matter that makes up a person isn't nearly as heat resistant as a rocket engine cluster specifically designed to withstand thousands of Kelvin in temperature. You will suffer skin burns, your hair is likely to smolder, your clothes might catch fire and you better hope your eyes are closed (or better, averted).

You also spin the "instagibbed by flying debris" roulette and hope for the best.

[cantab]

I'm inclined to think that if you were on the deck, you'd be seriously injured or killed *before* the rocket even touches down, it is a rocket engine firing practically on top of you after all!

[todofwar]

23 minutes ago, cantab said:

I'm inclined to think that if you were on the deck, you'd be seriously injured or killed *before* the rocket even touches down, it is a rocket engine firing practically on top of you after all!

I think the scenario is more it lands and everything seems fine but one of the kegs fails after someone has come on deck to secure it/inspect it. 

I don't have much experience with explosives, but I'm going to go with dive into the water. Even if you were on deck you'd probably be fine unless some burning fuel splashed on you, humans are mostly water which gives us a nice heat capacity 

[sevenperforce]

What cantab said. 

The SOUND from the Merlin 1D, even at low thrust, would kill you. No doubt about it. 

[PB666]

11 hours ago, PTNLemay said:

I'm sure we've all seen the videos, the Falcon 9 lands on the barge, everything seems fine, but a landing leg was forced just a bit too hard and the whole thing tips over.  Even though there's relatively little fuel left in it, it still manages to explode into an impressive fireball.  

How big a blast is it though?   Say you were unlucky enough to be on the barge shortly after the rocket landed (say it's your job to strap it down for the return trip) and it starts to tip over.   I remember from this YouTube video that in such a situation (where you're facing an explosion near you) jumping into the water might actually be a really BAD idea because it's an incompressible fluid.  

So you crouch down and cover your hears?  Could you survive?    Wikipedia says the drone ship is 300 feet long, so assuming the rocket landed near the middle, the furthest you could get away from it without falling into the water would be around 150 feet.  Now we need to know the approximate amount of joules that go off when it explodes.

I wasn't able to find the KJ per KG for rocket-grade kerosene, but aviation-grade has ~46 KJ per KG.   For comparison, 1 KG of TNT has 4 megajoules.

So yeah... discuss.

I take it a sudden bout of boredom overwhelmed you?

[KerbonautInTraining]

Well, if the thing was deemed safe to approach all the LOX would have been vented (something that can be seen in the RTLS landing video) which makes up mote than half the fuel by mass so the explosion would be significantly smaller.

[PB666]

7 hours ago, WildLynx said:

You missed the point form the scenario:

Rocket already landed, engines stopped, electrics switched off. Crew boards the barge to secure the rocket.

Then, suddenly, one of the legs fails, may be due to the huge wave suddenly hitting the barge, rocket tips over and falls flat. Kaboom.

I think, that best strategy is to jump overboard. Explosion will happen not in the water, but on the barge's deck. And I'm sure workers wear life jackets.

I'm the big hungary 3 tonne tiger shark circling the barge just waiting for that to happen , thinking man that was an easy lunch. Particular since the guy who just jumped doesn't have a way to get back up a barge that has 18 foot walls, forgot to grap his life vest, and was knock senseless jumping from 20 feet and body slamming an oncoming wave, only tonhave the rocket to fall on top of him. 

[PTNLemay]

On 5/9/2016 at 9:19 AM, PB666 said:

I take it a sudden bout of boredom overwhelmed you?

Umm... yes.  lol

[magnemoe]

On 9.5.2016 at 2:43 PM, WildLynx said:

You missed the point form the scenario:

Rocket already landed, engines stopped, electrics switched off. Crew boards the barge to secure the rocket.

Then, suddenly, one of the legs fails, may be due to the huge wave suddenly hitting the barge, rocket tips over and falls flat. Kaboom.

I think, that best strategy is to jump overboard. Explosion will happen not in the water, but on the barge's deck. And I'm sure workers wear life jackets.

In this setting your main danger would be to be hit by the rocket or rather the legs, fire is the secondary issue. 
As other says explosions are not equal, an fireball because oxygen and jet fuel get in contact because of leaks is an farly slow explosion who don't generate an serious pressure wave but might spray buring jet fuel around. 

[kerbiloid]

On 09.05.2016 at 3:43 PM, WildLynx said:

Then, suddenly, one of the legs fails, may be due to the huge wave suddenly hitting the barge, rocket tips over and falls flat. Kaboom.

 

 

Edited May 11, 2016 by kerbiloid