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Edward
Explosive forms.

If I want explosives to do controlled blasts what do I use.

I am talking opening high security doors I am assuming C4 would be an appropriate one but what shape dose it come in. placing a 1KG block of C4 on the door and running up the corridors doesn’t sound like a description of a skilled demolitions expert. Can you get the stuff as 1cm cord you tape to or wrap around an object or perhaps in a tube like a corking gun (great for masquerading as maintenance workers)?

Edward
Bigity
Yea, there is demolition cord used in all kinds of applications. I'm not sure what the exact material is, but I'd say you could get a C4 equivelent (in game terms) in just about any shape you need.
Zeel De Mort
You can create pretty controlled explosions using C4/C12 as they have a tiny blast radius and can be stuck pretty much anywhere and shaped how you like (i.e. make a Demolitions test to increase the power).

Also, SOTA 2063 has rules for Bangalores, and M&M has Spray Foam explosives, both of which might be what you're looking for.
FrostyNSO
C-4 can be used to breach doors by using multiple (5 to 6) charges (about .5 kilo) with steel runners stuck to a door and connected to eachother by detcord.

These are quite easily prepared and pre-packed, and once you get good at it, you can probably breach a door in less than 30 seconds.
Austere Emancipator
Ruleswise, C-12 is great for "confined explosions", since that stuff won't harm a fly beyond a few meters with common charge sizes. 9kg of C-12 will not damage anything at 3 or more meters away from the explosion, but will blow a 0.5meter hole into anything, and will utterly destroy Heavy Structural or lighter materials.

Don't try that at home, kids. It is not completely safe to stand 3 meters away from 9kg of any conventional high explosives going off IRL.

Detcord is not (or at least shouldn't be, I haven't got SOTA63) useful as the main charge for breaching anything sturdier than light wooden doors. They generally have a very small amount of high explosive inside, around 20 grams per meter in length or something like that.

Linear Shaped Charges might be sort of what you're looking for, maybe, if you want to get past thicker metal doors without huge amounts of explosives. Except, of course, that they don't exist in SR canon.
FrostyNSO
Detcord is virtually useless except for "priming" a desired break location. Think of it as "making" the grain for the axe to hit and split the block
Zeel De Mort
Oh, on second reading it seems there's detcord in SOTA 2063 as well. That does 12S along its length if you use it as an explosive. Blast is -1/m, which is odd when you compare that to C4 or C12, especially considering the detcord is filled with plastic explosive itself.

The Bangalore torpedos in the same book do 20D, which is quite a lot considering they were used for destroying booby traps and barbed wire fences. However I guess they've come a long way in 150 years or so! Anyway SOTA 2063 recommends drilling a hole through your barrier and shoving some of that through it. Interesting..
Crusher Bob
You can also use detcord to cut down trees. Check your field manual on how many times you've got the wrap it, based on the tree diameter and they type of wood. It's one of the ways to make an LZ in the woods.

You can breech most interior walls and almost any residential door with detcord too. For the heavy metal firedoors, you can blow if off it's hinges but not actually breach the door.

The best things about it though is that it's propagation speed is very fast (6000 m/s?) so you can set up multiple charges that need to be simultaneous, and link them with detcord. Saving you the complications and risk of using multiple detonators.
FrostyNSO
That's how door charges are made =)
Dice
QUOTE (Zeel De Mort)
The Bangalore torpedos in the same book do 20D, which is quite a lot considering they were used for destroying booby traps and barbed wire fences.

It takes a lot of explosives to make an appreciable gap in proper military barbed wire obstacles...a grenade or two will just make them untidy and dusty...

A typical Bangalore Torpedo section is 5' long and holds 9lbs of explosives. It's basically a long thin satchel charge
Crusher Bob
Also, a real obstacle will be pretty deep, maybe 10-20 feet. And cutting the actual wire especially when there is alot of it, will take plenty of work. And when the wire is mined, are there are guys with guns guarding it, it's gets even worse. Better to get some planes to drop bombs on the places you want the paths, and then to the much simpler job of 'tidying up'. Combat obstacle breaching is mostly for officers to order when they want to be able to comfort your grieving widow.
Austere Emancipator
QUOTE (Crusher Bob)
You can also use detcord to cut down trees. Check your field manual on how many times you've got the wrap it, based on the tree diameter and they type of wood. It's one of the ways to make an LZ in the woods.

My experiences on that were not very positive... Maybe the detcord we used had less explosives than what the US uses. The problem is that you're "crushing" the tree, which takes a whole lot of oompf. If you want to cut down a bunch of thick, living trees, you better have shitloads of detcord. Not that it isn't fun, especially with smaller trees...

QUOTE (Crusher Bob)
The best things about it though is that it's propagation speed is very fast (6000 m/s?) so you can set up multiple charges that need to be simultaneous, and link them with detcord. Saving you the complications and risk of using multiple detonators.

Should be noted that this is indeed the whole point of detcord. Everything else is just "you can also use it as..."
Rory Blackhand
Since C4 is a very stable explosive it will not detonate with heat alone or with force alone. In other words you can burn it or fire a bullet into it without setting it off, though I wouldn't fire a bullet into a burning block of C4 and I wouldn't fire a tracer round into a block of C4 either. And neither method is reliable, neither will produce an explosion every time, but they might. That is what a blasting cap is for. It is designed to produce both elements needed to detonate C4.

A non electric blasting cap is somewhat unstable. It only requires force to set it off. This is the purpose of det-cord. Det-cord comes in a roll and can be cut to any length. It is also unstable, only requiring heat to ignite. The blasting cap is crimped onto the end of the det-cord. The basting cap is then shoved into the block of C4. When a flame touches the det-cord it is ignited just like a stick of dynamite, the small explosion sets off the blasting cap, which in turn sets off the C4.

The source of heat to set off the det cord is usually accomplished with a timed fuse wire. It also comes in a roll and can be cut to any length. It is also marked with exact measurements. The fuse cord burns at a very consistant rate. It is a simple calculation to figure out how much of a delay you want. The more time you need, to walk away for example, the longer the piece of cord you use. There is also a fuse igniter that starts the cord burning.

I wanted to make two comments. First, the non electric blasting caps are somewhat unstable. They come in a box of ten and are packed in foam. They are not much bigger than a pencil and about half the length, but they deliver a nasty little explosion. They are a mini shaped charge and will spray shrapnel in a shotgun pattern. If some rough handling or enough force banged them around to set one off, it could hit and detonate any C4 you are carrying. On a Recon team we don't have one man carry both the C4 and the blasting caps. Maybe rules get broken in combat, but certainly not as a common practice. It is reasonable to ask players how they are transporting their explosives and it will take some time to set a charge if the equiptment was carried safely.

Second, the C4 itself is pliable, it can be shaped. Btw, to blow open a safe door that it took 4 men to lift took a snow cone cup sized and shaped charge. The C4 block itself comes wrapped in plastic. So if you were to detonate the C4 on open ground sure there would be a low blast radius and no shrapnel. However as soon as you place it in contact with steel you have created a source of shrapnel.

It happened to me once in demolition class when I was in the Marine Corps that it was getting late one night and so our instructor told us to use all the C4 we had left, but we were going to stand over by the bleechers instead of behind the blast wall so we could witness this giant explosion of all the remaining C4. We had been blowing up train tracks, metal beams, and sheet steel of various thicknesses all day, but he clearly said not to place any C4 near metal for this last explosion. Unfortunately even in the most elite units from across the world it is easy to get orders misinterpreted. So the 30 of us stood there in the twilight waiting for our charges to go off. When they did, it was apparant that someone had placed charges on metal because screaming pieces of shrapnel started flying all around us as one charge after another went off. It was like being on the receiving end of an artillery strike. There was a towering tree line of these old growth pine trees behind us, maybe another 20 or 30 yards further away from the blast, and the sound the shrapnel made in the darkness as it shredded thru the branches was a bit unnerving. None of us received a scratch though. But my point is, that when you apply shrapnel to an explosive you get fragmentation effects. True you can shape the charge, but a sliver of a steel is not going to fly just 9 meters and come to a stop. Just something to think about when you are in a hall or room and want to blow your way out of it with explosives.
hobgoblin
thermite would be another nice way to crack a door like that. its not an explosive so it more controlable.

as for the lethality of explosives, from what i understand the amount of pure force needed to kill a person is a lot. what kills are most often flying mass (nails, bits of rock or wood and similar). this is why they use heavy mats on top of blast jobs, these mats stop the spray of stone and other material. this is allso why a grenade is so mutch better at killing then trowing a lump of c-12 over to the enemy as the grenades often have a prestressed outer coating that is designed to fragment. and in fact you can survive a grenade blast in close range if the ground is hard. lay down flat and hope to god that the detonation becomes reflected upwards as thats the direction all the small items will go as well smile.gif

i recall a news story ones where someone took a sports bag, put a charge of explosives in it (dont know how mutch) and then wrapped the charge in screws, nails and other similar items. then he took it to a concert and detonated it on the crowd frown.gif instant insane fragmentation bomb.
Austere Emancipator
QUOTE (Rory Blackhand)
A non electric blasting cap is somewhat unstable. It only requires force to set it off. This is the purpose of det-cord. Det-cord comes in a roll and can be cut to any length. It is also unstable, only requiring heat to ignite.

I guess that depends on the detcord in question. The type I played around with required a blasting cap to be set off, and to ensure it does go off, the detcord was taped around the blasting cap so that cap points along the length of the cord.

A quick Googling leads me to believe that more stable detcords with a plastic explosive (eg PETN) core and that require a blasting cap is what is commonly known as detonation cord, since all dictionary entries and descriptions look like this:
"While it has the appearance of nylon cord, the core is actually a plastic explosive, and it is initiated by the use of a blasting cap."
Austere Emancipator
QUOTE (hobgoblin)
as for the lethality of explosives, from what i understand the amount of pure force needed to kill a person is a lot. [...]

Yeah, it's certainly easier to kill people with fragmentation than it is with just the pressure wave and heat. However, you immediately know something is horribly, horribly wrong when a straight explosive HE grenade (that weighs 0.25kg) has a wounding radius greater than 6kg of C-12.

Been discussed here a trillion times before. There's just no way around it: if you want the rules for explosives to make sense, you're going to have to use a flat Blast rating for all the Commercial explosives, preferably -2/meter (since that's what the non-fragmenting grenades use).
Edward
The problem with Thermit is that it is availability 10. Witch is very confusing considering it is made by mixing 2 completely uncontrolled substances (powdered aluminium and powdered rust) possibly with some form of binder so you can use it as a paste. The ignition sores for it is a little harder. Magnesium ribbon is probably the easiest to obtain reliable way to light it but party sparklers have a chance.

Edward
BGMFH
Thermite requires large quantities IIRC, and someone will notice the troll buying all the rust in Seattle
Siege
Hob - that's an old trick.

Explosive + metal bits = improvised anti-personnel device.

You can use nuts, screws, bolts and the ever-popular nails.

You could even use handfuls of coins for a change.

-Siege
Kagetenshi
Loose gravel, now that would rock.

~J
Siege
Ya know, that's not the way weed like to be stoned.

-Siege
mfb
your puns are without humor value. apparently, you all take the ability to tell jokes for granite.
JaronK
Maybe what we need is a more concrete example of how this should work?

JaronK
Siege
Nah. Cement what he said.

-Siege
UpSyndrome
Maybe you're just rocks...stones...aw shit I got nothin.

-Joe
mfb
fate doesn't have you slated for hilarity just now.
Siege
Mortar shale avail you not.

-Siege
Starfurie
Here's a real life trick that you may find a use for (stolen from the US Marines). Take a steel coffee can and cut it in half vertically. Line the inside with a thin layer of C4 or several lenghts of detcord. Fill the remainder of the interior with ziplock baggies filled with water. Wrap with duct tape then line flat side with double sided tape (do not remove second peel away layer). When you come to a door you want to open rapidly, peel second layer off of the tape, stick to door you wish to open, and then detonate the explosive (you may wish to step back first). Walk through now empty door opening.

As for linear shaped cutting charges, the important thing is the chevron shape. Molded copper piping will work fine when filled with C4/C12 and the 12S of detcord will work for backblast. As for penetration, a conical cutting charge will cut though 5 to 7 times the diameter of the charge of rolled homomoginous steel armor (a barrier rating 32 material). I would guess a linear cutting charge would cut through 3 times the thickness of the charge as the explosive force isn't as concentrated. Yea, it will pretty much blow a hole in any material in your way as long as there isn't too much of it.

Boom.
Edward
You don’t need that much rust. And you don’t by it you make it. Connect a chunk of iron to one terminal of a battery (cant remember witch) and chuck it into a salt-water bath. Next day you dry your rust and mix with powdered aluminium. I did this once and the rust you get is quite adequate. The difficult part is the powdered aluminium. Buying powdered aluminium is possible from chemical supply houses but it is not a common request and it takes a bit of effort to grind down window frames (this is why I didn’t make Thermite) with an appropriate jig and power tool you can do it however.

Considering Starfurie’s suggestions I am starting to see why explosives are not modelled accurately. As PCs are almost always the ones breaking in these relatively simple devises (chemistry workshop and 4 in demolitions and chemistry and you can make them easily) and there is no such thing as a door you cant open. It gets better when you cast stealth on the door before you blow the charge.

Edward
Kagetenshi
Then you have a big boom, but no clatter of door bits hitting things.

~J
hobgoblin
hmm, a silence around the door and the explosive maybe? its not 100% soundproof but it adds upto force on perception checks...

asfor the blast radius, my point was that a grenade have fragments calculated into its blast radius and small items have a bad habbit of traveling far, in fact longer then the normal blast area at times. commersial explosives dont have this calculated in but feel free as a gm to add them if you feel its right to do so. atleast thats my take of the difference...
Austere Emancipator
I'd put the Perception TN to hear 1kg of C-12 go off within 100 meters with significant background noise behind several walls at, I dunno, -8 maybe? Maybe if you used a Force 12 Silence on the area while there's a tornado raging outside the sec guards wouldn't notice...

And you'd still get the distinct sound of a mass of rushing air as the pressure wave gets outside the Silence AoE, as well as all that metal crap bouncing around at decent speeds.

QUOTE (hobgoblin)
asfor the blast radius, my point was that a grenade have fragments calculated into its blast radius and small items have a bad habbit of traveling far, in fact longer then the normal blast area at times. commersial explosives dont have this calculated in but feel free as a gm to add them if you feel its right to do so. atleast thats my take of the difference...

That's basically what I was trying to say. Fragments travel farther than the blast wave, let alone the heat, and are much better at causing casualties than the latter two. However, you've got High Explosive grenades which have no fragments at all, and those have a Blast Rating of -2/meter. So why the hell does the pressure wave from straight C-12 dissipate 6 times as fast as that from a HE hand grenade?

No reason, the rules are just really weird on that one. In one thread it came up that it had in fact been errata'd in SR3.05d (5th German printing) to -1/meter for all commercial explosives.
Hague
Maybe the writers knew that C4 type explosives are primarily a cutting charge, and went a little overboard?
Siege
I think you may be giving them more credit than they deserve.

Granted, if you didn't know anything about explosives, guns and a myriad of other stuff, I'm sure the rules would make a lot more sense.

-Siege
hobgoblin
the high explosive ones are not stated to be totaly fragmentation free, its still a encased explosive after all. there is allso the aspect of directed blasts. like say a solid inner core with the explosive wrapped around to try to deflect the blast outwards or something. but yes i agree that there are some oddities in there, most likley leftovers from older versions of the rules (rember that most of the electronics where just recently errataed). maybe we will see changes in the future. hmm, i should realy not be typeing this as im kinda tired. the question is, is it a rpg or a wargame?
Austere Emancipator
QUOTE (hobgoblin)
the high explosive ones are not stated to be totaly fragmentation free, its still a encased explosive after all.

Tiny bits of plastic. You'd get far more deadly fragmentation if you threw a handful of gravel or paper clips on 0.2kg of TNT.

QUOTE (hobgoblin)
there is allso the aspect of directed blasts. like say a solid inner core with the explosive wrapped around to try to deflect the blast outwards or something.

Absolutely no point. The end result is the exact same: all of the pressure escapes in all directions in a ball around the explosive. There's no black hole in the middle of the explosive which sucks up pressure.

SR wouldn't be shifted towards being a wargame if someone tuned the Blast ratings. When you can make the system more reasonable and realistic as well as simpler (single Blast rating for straight explosives instead of several) at the same time, I can't think of any reason not to do it.
hobgoblin
gamebalance most likely. why buy a grenade when you can buy a suitcase of c-12and just lob it at the enemy? most likley if you did so then you have wasted the entire enemy team if explosives where as you say they should be (not to talk about the damage effects done to the area around them)...

nah, why not just go and play blue planet?
Kagetenshi
A grenade is 30-60. C-12 is 200/kilo.

~J
Austere Emancipator
Kagetenshi already gave the most important reason -- on the street, you pay 60 nuyen.gif for the non-frag hand grenade, 600 nuyen.gif for 1kg of C-12 with a timer, 10 times the price (and 6 times the weight) for about the same blast radius. Other reasons include the ease of use (just Throwing skill for grenades, Demolitions too for the C-12-briefcase-dude and the need for detonators), weight (you get 10S -2/m with a non-frag handgrenade weighing 0.25kg, 8D -2/m with a 0.7kg charge assembly of C-12 and a radio detonator), and availability (10/48hrs for C-12).

So game balance is horribly against C-12 compared to hand grenades at the moment. After this change commercial explosives would still suck in that role except for pre-planned, rather high-cost attacks with very large amounts of explosives. Like, you know, the way they're used IRL (by terrorists, etc).
Kagetenshi
To be honest, as flat-out wrong as it is, those explosives tend to be more useful to me because of their low blast radius. It's really nice only having to back off a few meters rather than get waaaaaay back.

No, it doesn't make sense, but that does affect how it's balanced.

~J
Austere Emancipator
Yup, you'd actually have to go around a corner or something and not just take 3 steps back when blowing up 9kg of C-12. Personally, I've no problem with that.
Kagetenshi
You'd have to go a nontrivial distance down the corridor due to blast reflection.

Still not a problem, but the absurdly low blast radius does have some useful properties rather than solely crippling ones.

~J
Austere Emancipator
QUOTE (Kagetenshi)
You'd have to go a nontrivial distance down the corridor due to blast reflection.

I guess it depends heavily on your GM, whether and how much he thinks the pressure wave should diffract around the corner. With little or no diffraction and using the canon blast reflection rules, you'd probably be completely safe 5 meters down the corridor, a few meters behind a corner even with a 36D -2/meter blast. The wave would have to reflect back and forth so many times that it would dissipate very quickly.
Hasaku
Silence is a physical spell, right? I assume it lessens pressure waves in air within its AoE to achieve the effect. Assuming those two are correct, would you allow a silence spell to have any effect on blast wave propagation?
Austere Emancipator
Silence is an Indirect Illusion. Illusions in general do not affect their subject as much as they affect their targets -- it makes it difficult for people and technological sensors to hear, it doesn't actually dampen sound. Thus I wouldn't allow Silence to have any effect on blast wave propagation.
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