Explosive

Basic Information

Broadly an explosive substance is one that is capable of releasing a large quantity of stored energy (proportionate to its mass) over a short period of time, usually in the forms of heat, light and kinetic energy.

Most forms of explosive currently known release stored chemical energy - of which more later - the remainder are either nuclear explosives (releasing energy by fission or fusion reactions) or use some other form of subatomic physics (e.g. antimatter - although this is still a theoretical explosive for most purposes. In sci-fi settings other forms of exotic matter might also be explosive. Theoretically compressed gases could be thought of as an explosive storing mechanical and/or thermal energy, but this stretches the boundary of the class a bit.

Chemical explosives are traditionally divided between the low explosives which deflagrate (burn rapidly) in air and create a subsonic blast wave and high explosives which contain their own oxygen and detonate faster than the speed of sound. There is also a (less sharp) distinction made between primary explosives which are sensitive and easily set off and secondary explosives which are less so.

Many low explosives - such as black powder are used as propellants for firearms, but they are also useful in pyrotechnics, in an incendiary or for blasting operations that involve lifting and throwing loads rather than shattering them - such as stump removal, ditching and many mining and quarrying tasks. Fuel-air explosives are a common, specific type of low explosive and can be encountered either in the form of a Thermobaric Weapon or, more commonly, as an industrial hazard.

High explosives are of much more interest to PCs in most cases since they are the ones used as fillers for grenades, shells and bombs in the modern world¹. As well as the lethality of the blast wave that they generate their high speed explosions are good for cutting and shattering.

Primary Explosives are a menace to handle and sane people use them in the smallest quantities possible - they are the sort of thing used for the primer caps of ammunition and in the detonators used to fire secondary explosives. Of course, in the early years of high explosives - and particularly in the nitrogylcerine era - they may be all you have and the powder monkey's job becomes even more dangerous than before. Many primaries can be triggered very easily by shock or friction … or static electricity, or light … you get the picture. For most applications the more stable ones are preferred but the age and purity of the compound can have a real bearing on how safe it is to use.

Secondary Explosives require some significant input of energy before they are set off - black powder², for example, requires flame (or at least a spark), whilst some modern plastic explosives are safe enough that they can be burnt without detonating³ and require an initial explosion from a detonator.

Some key features:

• Black powder
• Detonator
• Plastic Explosive
• Foam Explosive
• Fuse
• Detonator Cord
• Dynamite
• Nitroglycerine
• Slow match
• Thermobaric Weapon
• Gun cotton
• Nipolit

The other thing to be aware of when using commercially made explosives is the presence of taggants - additives put into the blend to impede covert use. They come in two varieties - detection taggants volatile compounds that evaporate over time and are designed to be picked up by sniffer animals and mechanical detectors, and identification taggants which are resilient polymer beads designed to identify the source of a given charge, even after it has exploded. Whilst detection taggants are pretty universal⁴ the only nation that mandates tagganting of explosives made on its territory is Switzerland - use elsewhere is patchy to non-existant.

There are, of course, flaws in this system - home made explosives are not tagganted in any way shape or form (although they are usually more detectable than the same compound made by professionals), and it would be frankly dumbfounding if most nations didn't manufacture at least some "clean" material for the use of their special forces and/or intelligence agencies. Also, given that for tagganting to work as a deterrent to crime details of taggants need to be widely circulated around law enforcement agencies, it should be fairly simple for a nation wanting to conduct a false flag operation to spike its own clean material with fakes of somone else's taggants.

…and speaking of home-made explosives … there are a variety of different compounds that can be manufactured, some of them better and safer than others. A lot depends on the quality of the synthetic chemistry that goes into making them - possibly as much as choice of target compound. A lot of the prep methods in popular circulation are for dangerous, unstable compounds that are hard to manufacture safely and a cynical observer might wonder if someone hasn't circulated them deliberately to the detriment of wannabe bomb makers. Also, many of the best precursor compounds are watched by chemical supply companies who are prone to alert the authorities if they see them being purchased by 'suspicious' persons.
Incompetence in this line of work is likely to be dangerous.

See Also

• For information about the wounds and effects caused by explosive devices, see Blast Injuries.
• For information on blast radius and shrapnel density, see Inverse-Square Law.
• For information on explosives outside of an atmosphere, see Explosions In Space.

Sources

Bibliography

(Probably not good things to be caught researching at the moment)

Game and Story Use

• Like firearms, a great force multiplier when used properly.
• That thing about taggants should probably give people a few ideas.
• The powder monkey is a recognised combat role in (cinematic) military fiction - probably equivalent to The nuker, as is the booby-trap engineer.
• Explosives - not just for violence - as mentioned, also good for pioneer work, demolitions, mining and the like.
• How easy it is for the PCs to produce home-made stuff should depend on where they spent their 'non-combat' skills - although in a cinematic campaign you may wish to hand wave it. In a realistic campaign it is likely to be dangerous and prone to attract the authorities.
• Likewise, the PC's enemies may or may not be any good at making explosives … incompetence may make them more dangerous - be extremely careful if using material captured from amateurs.

*

Footnotes

1. In most cases. And of course, in the pre-modern era they don't exist

2. Caution: many authorities consider black powder a primary explosive - how easy it is to ignite depends on the exact preparation, but it does fall on or close to the border.

3. To some degree. Whilst it is true that you can cook with C4 if you don't mind ruining your mess tins and stove, that doesn't mean that it's safe to light a brick of it, cook marshmallows and sing the ginganggoolie song. Problem is, it burns hot and fast and if you light a big enough lump it can get to burning fast enough that it starts to deflagrate rather than burn … now deflagration, that's what we've just said low explosives do. What sets off PE? Explosions. Do low explosives explode? Was that bear carrying a toilet roll? And where did the camp cook just disappear to?

4. allegedly