What are the odds on a shotgun blast being able to cause a propane tank to explode (4-5 meters away)? The propane tank was one of the larger kind, sometimes found at gas stations for fill-ups (in case the OR would be different than the small kind) and the shootist was 4 meters away. Can you tell that this came up in a gaming session?

The inside of the tank would be nothing but propane gas, right? You need a mixture of propane and oxygen, plus an ignition source to make the propane start burning, and unless you're constantly bringing in additional oxygen, the fire will snuff.

If the inital pieces of shot at the front of the shot were able to pierce the side of the tank, you'd have propane leaking out to mix with the air. If the pieces of shot after that were to cause sparks while hitting the tank, the propane leak may catch fire. However, the bulk of the propane is still inside of the tank, and is leaking outwards, preventing any air from getting into the tank until the pressures equalize.

I'd say worst case scenario, you may get a jet of flame, but the whole thing wouldn't imediately go up. Except in Hollywood, of course.

I would assign an armor value (3-6) and a body (2-6 thickness matters more than size) to the propane tank and determine the damage it takes reduce damage for flashet as with armored targets.

Should it take S or greater damage it has ruptured. Now look for ignition sources, chances are that a single slug traveling threw a propane tank will not ignite it. Slower pellets from a shotgun may but I don’t like your chances, incendiary rounds or tracers will have a high chance.

Not propane is a highly flammable gas and not all that unnatural. I would say you need a 10 on 2d6 to ignite it with a single slug, 9 with a shotgun blast, 6 with tracer rounds and 5 with incendiary rounds. (tracer, incendiary or big D’s temper fired after tank ruptured 4,3,2 respectively)

This is taking some liberties with the rules but according to the rules for setting something on fire petrol is harder to light than wood (petrol OR 8 highly flammable -2 target 6, wood OR 3)

Edward

The only quote for propane tank thickness I could easily find was for this (from another angle) 288-gallon tank (converted to a submarine), which has a 3/8" (9.5mm) thick steel hull. That ought to withstand any shot hit without rupturing. If those were slugs, though, and the tank was hit dead-on, it just might deform the tank enough to cause it to rupture as a consequence.

Penetrating a tank like the one in the pictures with a shotgun is simply not possible, unless you have some kind of armor piercing slugs, so AFAIK the tank should not explode anyway. Although a violent rupture of such a tank might have very similar effects. I haven't a clue if propane tanks usually have sufficient internal pressure for that sort of thing, though.

On the otherhand, if the gas tank is penetrated, the gas could potentially exploit the breach and cause an explosion that way, particulary if the tank is full. Better get Hank Hill on the phone for this question.

I heard somewhere that propane was a liquid...I may be full of crap. It's late.

Propane is liquid when under enough pressure. Any gas can be liquified by applying enough pressure to it. Most of the propane in a tank will be liquid, because of the pressure that it is at. As gas is released pressure is reduced and more of the liquid boils.

This linkmight be helpful. If might not be.
http://www.gswagner.com/propane/propane.html

A tank won't explode because of a runshot, but it will explode from being overheated. For holloywood style effects, lob a fireball at it.

One thing to consider is what precise meaning of the word explode is being discussed here:

• to undergo a rapid chemical or nuclear reaction with the production of noise, heat, and violent expansion of gases
• to burst violently as a result of pressure from within

The chemical reaction/heat/violent expansions of gasses will only happen if you can mix the propane and the oxygen in the correct proportions.

The burst violently due to internal pressure could happen with a weakening of the tank's walls, or a sudden increase in pressure (i.e. due to heating from a fireball)

Of course, overpressure-induced-violent-bursting explosions release the propane to freely mix with the air, which can easily lead to chemical reaction explosions.

or basicly your own home made FAE
hell, thats what a FAE is, a big tank of some gas or other that at a set time is ruptured and the gas distributed somewhat evenly in the area. then a moment later a spark is made

Like I was trying to say, a shotgun firing shot should not penetrate any propane tank, and will not even dent it significantly. Most types of armor piercing ammunition, if they hit at a 90-degree angle (ie. straight to the centre of the round tank), should penetrate and cause a leak. Whether the spark from such a penetration would be enough to set off a fire and/or explosion, I haven't a clue.

Give it 2-6 points of vehicle armor, depending on what you think is appropriate. That'll take care of AEs arguement. As far as actually sparking enough for lighting it... rarely.

I thought trick shooters use special ammo for getting sparks if they try to light something on fire? Copper and lead bullets just don't cause sparks consistently.

But in the end that all depends on your game.

If the players like guns and explosions like you see in the movies, the tank explodes without hesitation!

If they like an occasional nod to realism, give it a chance to ignite.

And if they want to slow down the game with physics and common sense, you ask the question here.

2002 Darwin Awards Honorable Mention

"DAMIT BOBBY! Why would you want to shoot a tank full of lady propane.....That boy just ain't right I tell ya Peggy. Propane and propane accessories are dare I say it ‘holy’. Why would want to go shootin up propane tanks. If the Texas National Gas commissioner Buck Arwald heard about this, I think he'd cry...."

-Hank Hill

So shooting and puncturing the tank didn't cause it to explode, but the propane-air mix it created afterwards was highly flamable. That's pretty much what people have been saying isn't it?

This is where we should send a suggestion to that Mythbusters show on cable to see if they'll experiment for us.

Not a bad Idea at all, I like that show.
But this isn't really a myth is it?

The same as the myth that you fly back 10 feet when shot by a shotgun I'd say. Hollywood physics at it again.

I'd say it's on the same class of hollywood physics as handguns being able to cause a car's gas tank to explode or even the routine explosions of cars upon crashes (I mean maybe if everyone drove Ford Pintos but detroit isn't that bad anymore).

Another point is that even if you punch a hole in the tank and light the gas you may only get a flamethrower, not an explosion.

As the honourable mention learned

Edward

High enough pressure and you might get something more like a rocket as the discharge of gas might be enough to move the container a good distance. I don't think they keep propane that compressed but oxygen bottles etc might work.

hmm, mythbusters, nice series. one of my favs must be the drainage pipe+racoon+gas+redneck with lighter episode. why? the badly burned racoon toy sitting on the pipe when they launch buster (their crash test dummy) using a explosive charge

could allso be that washing machine from hell, where when they finaly get attached a strong enough motor its a electric car engine and the only thing left of the machine is the part that holds the clothes

man i wish i had the knowhow, toolshed and funding to do crasy stuff like that

One thing people forget is that it's a game.
When it comes to cool ciniematic scenes, sometimes you gotta go hollywood. Have the ghoul fly apart in a hail of bullets, have the random car flip 20 times and miss the PC's by milimeters, have the PC take a snap hip shot from 90 meters and nail the target the size of a nickel without blinking. Why, cause it's cool, people will remeber the occaional cheesy over-effect of such scenes.

I say, solid slug from a shotgun blows a nice big hole, the tank ruptures, 30 seconds later the condesnor on a nearby thingamajig clicks on and boom, instant urban renewal.

Yeah, Mythbusters rocks, I think I might name my next high bod human character buster.

Is there some reason we've dumbly decided cinema and drama have to be synonymous with absurdity?

No. But we don't play a game for the reality, do we?

In reality most man portable firearms would barely move a human being, but it's so much cooler to see them knocked back into furniture, other oponents, etc.

Why? What is inherently more awesome about firearms that make no sense?

cause
esplosions = testosterone appeasement

Nikoli, It rubs the lotion on the skin is just plain "WRONG"....I like it but it's wrong.....Damn you can find anything on the Web.

Just for the record, sometimes blowing stuff up is just plain fun....If it wasn't then there wouldn't be so many cheesy explosion special effects in movies. Case in point Nakatomi Plaza.....Big Boom.

as I said, big esplosions = testosterone appeasement. even my wife like big esplosions in movies

and, she's the one that found that video for me Kryton

until i see a propane tank explode they wont in my games, but i run a tight, (semi)realistic ship.

alot of people don't like me either

"tonight at eleven, a teenage boy levels a ciy block with a dozen m-80's. Also, can chocolate make you live longer? this and more at eleven o'clockwith the hard hitting action news team."

My point, really, is that big explosions and shotguns that send you to the moon are stupid, and they sure as hell aren't a guarantee of style.

Yes, as an element, over the top effects can be used as a stylistic element. Desperado and Once Upon a Time in Mexico are probably the first movies that come to mind. They're over the top, they're dripping with style, and they feature shotguns that on multiple occasions send me people soaring across bars, through chruches, and off rooftops. They also do not take these scenes seriously, as that would pretty much destroy any credibility or intelligence the films possess.

Then consider, say, Cowboy Bebop or the Bourne Supremacy. The action is brutal, fast, and real. With perhaps a couple notable exceptions, the action sequences are all extremely short— far shorter than anything in Once Upon a Time, let alone the ridiculous idiocy of Die Hard— and yet they stay with you. They're character driven, dramatic, and meaningful— not gratuitious, over the top studies in special effects masturbation.

I like Bruce Willis as much as the next guy, but I will never be able to take John McClane seriously. And I sure as hell can't stand it when a movie can't respect my ability to think, and instead resorts to wowing me with boring explosions, hoping I never stop long enough to ask whether this is all really necessary or even remotely plausible.

In Die Hard I'd always figured that he just used the monitor to keep the C4 securely fastened to the chair when he pushed it down the shaft. The big kaboom came from the fact that'd stolen a big bag of C4, along with the detonators. Not because he used computer equipment.

Well, I ruled the tank exploded. I don't have any real world explosives training. I relied mainly on what I thought would happen and (in truth) a lot of cinema.

My reasoning was that I thought there was enough damage done to the tank to breach the OR and the propane tank was located next to an outdoor ice machine. I referenced the explosion scene in Fight Club as the reasoning for the spark that ignited the gas. Eh, if that was lame, it wasn't because I just wanted to see an explosion. Enough of that seems to happen due to the use of grenades, rockets, and missile fire in the game. It just felt right.

I was just curious what everyone here thought on it. Thanks.

Yeah. Just do what works in your game. Some people like more realism, some people like more explosions -- find your own happy middle ground, and roll with it.

Also, the monitor would have provided the charge for the detonators, but the chanches of it actually hitting the detonators with the right amount of electrical charge and not just redering them useless is slim to none.