Why do explosives (like C4) have such large fall-offs with damage?

For instance, 50kg of C4 (rating 6) has a damage rating of 42D, but it falls of 6 power per meter. So it's only going to effect anything that's within 7m of the blast point.

Doesn't that seem a little light on for 50kg worth of explosives, or am i a math-tard and haven't worked it out right (rating x sqare root of Kg used). True enough it'll ruin anything in that space, but standing 9 meters away and being unscathed is a tad strange.

Please correct me if i'm wrong!

I picked up my explosive knowledge from Roadrunner cartoons, and based on that I have to agree with you!

While we do read the same chart (SR3 p. 283) you see, and do interpret it the way you describe, we use that reduction in power only for properly-formed and properly-placed charges being used to destroy a barrier where no one is intentionally or accidentally introducing shrapnel into the blast.

When explosives go off amidst vehicles or gear, or when someone deliberately or accidentally introduces shrapnel into the blast, we play as if the falloff in power was 1 per meter. It may not be canon, but it works for us.

Maybe the damage falloff should be tied to the sucesses in a Demolitions test? Better placement means less dangerous shrapnel and more focused force (away from the people nearby)?

Could it possibly be because industrial-grade explosives (barring TNT and such) are actually highly contained explosions meant for precision work?

Athenor

Has been done before, and everyone who knows anything about explosives agrees that the Blast rating for all explosives, regardless of their Power, should be the same. What exactly the Blast rating should be, we've never really gotten a good answer on.

It should probably be around -2/m (-1/0.5m), perhaps a bit higher. I use whatever I feel like, which generally means -3/m (-1/0.33m) when there is no debris around, like a kilo of C12 sitting on a stone floor, which goes down to -2/m if there's enough debris (small rocks, metal junk, etc).

Using Demolitions to make the Blast rating better is limited to either gathering the debris from the site of explosion to a pile on top of the explosive device (which generally won't help much) or making a fragmentating bomb in the first place (which might help a lot, depending on the size of the charge and vehicle and so on).

I won't use -1/meter even when there's lots of natural debris, because that generally won't be as effective as are the fragments on a hand grenade, mortar round or artillery shell, which are the kinds of explosive devices that do have -1/meter Blast in my games. However, that kind of reasoning won't hold in an otherwise canon game where even an Anti-Vehicle Mine has a -1/meter Blast rating.

So, umm, yeah, if you want explosives to be really, really leathal, just go ahead and use Blasts in the -1/meter through -2/meter range, depending on number and quality of potential shrapnel. For slightly less lethality, use Blasts in the -2/meter through -3/meter range.

It would be great if there were any army engineers around to comment (and I mean people who've been at it for a long time, and who have training for blowing people up and making anti-personnel explosive devices), but that hasn't happened once in the past 13 months and (at least) 3 major explosives/demolitions threads.

Or perhaps its just 2060 and the plastique is more advanced that we know...?

Its a convenient explanation if you're looking for a plot-flange and aren't a demo expert!

In one of the runs in Survival of the Fittest there's an explosive in there which is, as far as I can tell, a stock Shadowrun explosive (I don't remember which; CXII?) which falls off at -1/meter. I have no idea why this is different from everything else, though...

~J

I'm just baffled that Plastic XII (Power 12) creates exactly the same size boom as the same amount of Plastic IV (Power 6) and Commercial (Power 3) does. One kilo of any of those has no effect outside of one meter, so you can stand three feet away and just feel a slight breeze after detonating that large chunk of explosives -- neat!

And apparently, the Xth corrected printing of the German SR3 has -1/meter for all commercial explosives (I think it was SR3.05D or something like that). That too came up in one of the Old Forum demolition threads. I can't remember which one and I couldn't find a link, but I'm absolutely certain that was in some errata somewhere.

Well yeah, if you think ignorance is acceptable. I don't. At least when it comes to ranged combat and explosives etc.

OK. Well, I was just trying to be funny with that last one. I can afford to be funny about ranged combat and explosives because I'm likely to never be involved in either in Real Life ™!

You're absolutely right. I'm sorry, I'm just a very un-funny person.

Speaking of explosions, does anyone really have an idea what kind of boom different fuels make? Such as:
Diesel
Gasoline
Jet
Methane

I've researched approximate weights (3 kilos per liter Gasoline, 4 for Diesel and Jet), but have no references for what type of explosion (I've been eyeing the FAE rules in M&M, but they give no guidelines.)

Incendiary or EX-Explosives would both ignite the stuff, sure, but wouldn't make it explode. Unless we're talking about minute amounts of the substance.

In the Composite Explosives thread, we sorta concluded that with 5 gallons of gasoline, you'd need at least the hand grenade (not flash bang) to make it explode. For a vehicle's full fuel tank, it would certainly have to have the charge size of a frag grenade (~80g TNT IRL, AFAIK (abbr hell)).

So if you want to level a few city blocks, use a 5,000 gallon fuel truck + 10kg C12.

If you want to make the FAE rules more sane, change the Radius to something like (Kg x Rating)^0.5 and ignore the change of price in the new errata. [Edit]This would mean that a 5 gallon gasoline tank would do 6D in a 6 meter radius, -1/meter beyond that, + the explosive that set it off (assuming 0.675kg/liter and Rating 3). The 5,000 gallon fuel truck would do 6D in a 240 meter radius, -1/meter beyond that, and 38D from the C12.

And now I'm thinking 5,000 gallons of gasoline probably wouldn't vaporize like FAEs are supposed to, even with 10kg of C12... But it does make FAEs sufficiently mean for many other purposes.[/Edit]

Actually, I was just going to trash the radius rules, FAEs spread the explosive first, THEN detonate it. Without the spread, I'd think a tank would have an effective radious -1Power/2 or 3 meters.

Since you've apparently considered alternative explosives, do you know anyone who's considered a Sodium/Water load in a Capsule round, or have any idea the kind of micro-bang it might make (specifically, could it set off a gastank, perhaps?)

Yes, it could. It generates enough heat to do so.

Anything in the first column on the periodic table, when mixed with H2O, makes a nice bang and some heat. The lower it is on the table, the bigger the bang and heat.

Okay - chemist/biological/mad scientist background here...

Firstly, go find a few pyro sites, you know, ones with strange people who think making C4 in your garage is a fun and exciting hobby?

Then you go and grab a few MSDS (Material Safety and Data Sheets.) There are thousands of sites online, and it's a good way to be really scared of what is actually able to be bought over the phone with a credit card.


The tradition of "grenade in the fuel-tank" is a long and happy one - It works well with planes because they use Kerosene (no idea of what translation I'd have to do for the Americans...) with a bunch of additives. It's cheap-ish, burns hot and well and gets a lots of energy from it... You can't run a plane on Auto fuel, even Diesel.

(It will make the carb choke and die, big-time There are a few interesting stories of this happening to propeller planes in the USA...)

Ok, with trucks? Unlikely to have the movie-explosive effects all shadowrunners dream of. Diesel needs to be heated and compressed. (I used to know the flame/spark points, and they're high...) for the spark-point, but if you've a few indenderies, you'll have enough remaining heat to warm the rest enough to start a combustion reaction, promoting a more interesting fireball.

Propane! Now, this is great. Most industry has at least one large (20-30 feet?) propane tank, used for various things, mostly for boilers, etc. Now, these babies have a total kill/blast zone of ~roughly~ 75-150 meters. Compressed, explosive flammables...mmmmm....

Now, if there's a tank-farm, well, your day has gotten brighter. Say you have 4-5 of these suckers? Well, during a fire in Oz a couple of years ago in an industrial estate, one of the smarter chiefs grabbed a truck (over the outrage of the owners watching their business burn to the ground) to hose something that wasn't anywhere near the flames. What was it? A propane tank farm.
Estimates by experts worked out that the 4 full tanks would have levelled everything in a quarter-mile radius of the blast site.

Now, that's gonna sting.

Want a cheap FAE? Hijak a propane truck. Hook up a remote rigger/decker virtual cockpit. Or a smart drone. Pack the truck with, say, 5 kg of plastique? And a couple of extra detonators. Rig a dummy, drive truck to location, blow it.

Chances are the shockwave alone will pulp people within a 100-200 m radius.
Cover the truck in refractile shrapnel (Ie: high temp. Drill bits are an excellent example.) and there will be a cloud of death raining down for some time to come.

Methane? A short brief explosion - it burns hot and fast.

Actylene? Same. (I've lost my eyebrows many a time.)

Sugar? Ok, when sugar is heated, it caramelizes (Ie: turns brown.) and changes from a discrete crystal to a amorphous mass. This means that with a drum of say, jam, you can make napalm faster and easier than the old "Gas and OJ concentrate" (BTW, the typical OJ concentrate is, maybe, 40 Brix (~40 % sugar.) but jams are between 66.5 and 68 %, because higher and it will crystalise out. Honey is +80 Brix, but the sugars in honey are shorter and more "fragile" so no handy napalm in the honey-pot gags for Winnie-the-Pooh fans. Phew.)

Basically, to make something flamey, you have to choose a compound that has enough to it (Ie: the compound is large and simple enough) so that the heat input has a lot of fuel to work on, but not small enough so that it will be consumed utterly (Ie: secondry chain compounds needed. Maybe Tertiary, if you're lucky.) without delivering a high degree of heat.

I could go into how tertiary bonding is best as it will generate the mostr heat when the bonds are broken, but the rule of thumb is that if a combound has a lot of hydrogen and carbon, chances are that it will burn and produce heat quite nicely.

If it's a big molecule, it will need a lot more heat input before it starts to break down, but when it does, it will burn longer.

Which is why you can lose your eyebrows to a paint-thinner exposion, but are more likely to kill yourself welding an empty fuel tank than a full one. (It's a vapourised environment, needs only a small amount of heat input before combustion and explosive expansion, the full one needs to vapourise first, so it's slower.


Gods, what a disconnected rant.

L.

All I know about it is there's a Propane 'farm' in the midlands of England which estimates say would outright kill everything within 2 miles and level everything within 15 if it exploded. Now THAT is a big bang. The farm is no more than a hundred metres per side (I think its just a storage area, with underground tanks. I don't know for sure), and you aren't allowed to bring a naked flame or mobile phone within 3/4 of a mile of the gates.

I remember some RealTV! video of a gas truck exploding in Mexico (City?). It was a huge boom, but worse was when the underground storage went up.

Just wow.

Not very helpful with the discussion going on right now, but I remembered something else from RealTV!

There were 2 guys firing AK47s at a fuel tank trailer (about 500 gallons/2,000 liters by my estimates, but it might not have been anywhere near full). They were firing in short bursts, and it took the first mags' worth to get it to a good flame (these were probably good old-fashioned FMJ, not incendiary, rounds), and after the second mags it erupted into a huge pillar of flame. With API or HE rounds, that would just happen quicker -- it wouldn't explode.

Ok, I had the specs for propane fittings a while back, but can't find them...

But it's thick (the tank), at least 3/4 inch steel with polished welds (More on fittings, boiler standard at least.) and has been severely pressure-tested to 6-10 times it's operational capacity. Most are X-rayed now as a matter of course.

The fittings are usually non-return (Prevent fire getting in...but what about the gas outside? Oh...) and are of excellent quality.

There is a pressure release (blow-down valve) fitted to the lowest point of the cylinder which is protected with a few welded-on sacrificial plates and the biggest locks and bolts you'd ever see. On top is the access hatch - sealed - pressure gauges, input points (ultra-non-static, no-leak type positive fittings.) and "Flammable, do not smoke/approach with naked flame" in lettering 15-25 cm in height.

To blow the damn thing needs temps in excess of 600 degrees C for 30 minutes (I'm sure that was the requirement) or some sort of shaped charge.

Even though the damn things are pressurised, it's built to withstand a certain amount of punishment and outright abuse.

If you want to see if you can breach it with solid slugs with your Remington, please, go ahead. Just set up the camera out of the blast zone and send it into funniest home videos... Or organise your executor to do it...

L.

This reminds me of the first run I ever did with the group with whom I've recently been playing. There was a petrol tank in the corner of a downstairs room under a motorcycle shop; a gang of trolls had taken over the shop years ago (it was previously abandoned) and made it their home. The team was supposed to go in and get the gang leader's helmet for a rival gang.

We have, entering the building, an Assassin, TrollMin/Maxer, and Elf Cat Shaman.

Assassin: Okay, so I slowly walk down the stairs. Do I see what the shaman saw earlier? Has anything changed?

GM: Everything seems the same as when the shaman was here astrally earlier. Five trolls are sleeping in couches around the trid.

Assassin: Okay, I go in and ready my weapon to cover the others as they come down the stairs.

GM: You're standing where? (pointing to the map, the team had already discovered the tank but still hadn't figured out what was in it, and nobody brought a flash light)

Assassin: Um, not there. How about the other corner of the room?

GM: Okay. TrollMin/Maxer, you're next.

Troll: Okay, I follow him down and stop at the base of the stairs. *Assassin cringes* I ready my HVAR.

Every player but the troll knew enough to stay away from the big tank, no matter what was in it. They got very lucky that one of the trolls didn't grab the light pistol off the table and miss one of them, turning the whole building into a big fireball.

Whoops! Re-reading, may be able to answer a few issues.

1: A bullet, especially a high velocity, APDS round will pierce the tank, however, if the tank is anywhere near full, the gas escaping will alert anyone is a 200m radius that something isn't right as it makes an awfully loud whistle. Think a stove kettle multiplied by infinity.

2: Barrier rating? Let me check over the books.... Ok, I'd rule it a barrier of 15, at least. The stuff is thick, well made and under a stringent set of standards. Interestingly, the tanks on trucks are thinner (Weight is a bitch) but a bit more structurally-sound, as internal reinforcement is common, apparently.

(...Yeah, sure, we ALL carry a gun or two that could pass through 2 inches of mild steel and still split the engine block of the truck behind it... Walk away from the fireball then you pyro. )

3: Smaller, such as the BBQ propane? Well, damage would be around Deadly 8, ~2-5 meters , drop off of 2 per meter afterwards. This all depends on how full the tank was. And if you're standing next to it.

But those things only hold ~33 kg's of compressed propane, not 2000+ kg's. (I think it's closer to 3600kg's, but I can't remember.)

I'd also like to point out that those little cylinders are really over-engineered for their size.
If they go bang, usually people are hurt (In order of injury/fatality) by shrapnel, secondary fires, the bottle rocketing about and then "explosion".

(Read the papers regarding propane tank "accidents" if you're really interested.)

4: An empty tank is more likely to explode - The lower volume of gas inside the tank will make it more likely to have a greater degree of vapour (Mixture of a liquid and a gas, gas predominant) which has a tendency to explode first (Lower enthalphy needed to ignite substance) and then take the rest of the tank with it.

This is the reason why, when blowing something with a FEA, you leave a door open . More Oxygen = more bang for your dollar.

L.

That's pretty damn helpful, thanks a lot.

never use hollywood or cartoons as reference for explosives! ever!

any fule in liquid form does not explode, it only burns. in gas for tho (as in a cloud) do explode tho, from what i recall its the amount of oxygen in the mix that does it. this is what makes FAE so nasty, it is a gas cansiter that lets the gas spread for a bit before igniteing it.

in ww2 the bombers used bombes rated in tons, now we use ones rated in pounds, the reason is presision. if you can hit closer to target you risk less area damage with a smaller charge.

the reason grenades have the large blast radius is fragmentation. a kilo of c4 will not do mutch unless your sitting on it or is very close to it under water as the pure shockwave needs to be way up there to kill you. now flying metal or wood thats a totaly diffrent story.

i recall someone ones put a homemade pipebomd inside a gymbag filled with bolts and nails, carryed it to a event of some sort (a consert maybe) and then detonated it. 90%+ or so of the wounds and fatalitys was an effect of the loose stuff around the bomb.

just think about it, a rush of air is just that, air. if its comeing at you at supersonic speed its still air. if you want to take down a building you blow out the support structure, not just pile a load of tnt into it and light the fuse. thats why the federal building bombeing was so nasty, the had parked the van right next to a support.

i guess this stuff have been coverd by other posters but i just wanted to vent some stuff if your in my game and wnat to make a antipersonel charge from c12, wrap it in bolts and screws, then i will give you a -1/m (man i need a insane smily here. heh, didnt read tiralee's posts before now, mostly duped what he said...)

Don't knock air -- even if it doesn't knock you over, it can knock other things into you which will hurt. Or knock you into things that will still hurt.

Yes, shrapnel is a bitch, but so is blast pressure if you're close enough.

-Siege

yes but the power of air will drop very rapidly as its just that, air. we must to storm force or above to be able to toss people around by pure air and i realy want to see what explosive can produce that kind of shockwave if your 2-3 meters away from it.