Alfred Nobel's great invention, dynamite consists simply of nitroglycerine adsorbed onto a stabilising medium such as kieselguhr - although "off label" manufacturers have been known to use all manner of substances up to and including sawdust. The resulting material was traditionally formed into sticks and fitted with a wax or carboard wrapper to keep it together
Dynamite is generally rated with reference to the %weight of nitroglycerine adsorbed onto the stabiliser - 40% is usually the lower limit, giving a relatively slow explosion good for lifting and throwing (and therefore popular for mining work, ditching and digging out large boulders and tree stumps from fields) and 80% the higher end, giving a faster explosion that is good for cutting and splitting work. The other common mix, 60% dynamite, is either useful for both jobs or neither, depending on who you ask.
Nobel made himself a fortune from dynamite because it was the first way anyone had found of making nitroglycerine safe to handle and therefore the first practical alternative to black powder as an applied explosive. Of course it still had its drawbacks - stabilised didn't mean safe and the sticks still had to be handled with care and protected from flames, bullet strikes and the like - and over age dynamite, or sticks that have been allowed to freeze 'sweat' nitroglycerine which forms beads or crystals on the outside of the stick. These crystals consist of fairly impure nitroglycerine and are very unstable, easily capable of igniting the bulk of the charge if handled.
It was also found to be possible to extract the nitroglycerine from dynamite by boiling it in water and skimming the layer of hot, wet, impure nitroglycerine from the top of the resulting soup. Possible, but not exactly wise.
Confusingly military dynamite is not dynamite at all but TNT, which is completely different stuff and most modern 'dynamite' that is sold uses ammonium nitrate rather than nitroglycerine as the active and so is also different stuff.
Several ordnance designers introduced weapons that fired dynamite - usually by compressed air given that it was still not entirely tolerant of the short of shocks inherent in firing using a conventional propellant. They were rapidly made obsolete by the introduction of more stable military explosives.
Game and Story Use
- Few Cowboy movies would be complete without someone throwing a fizzing bundle of dynamite - particularly if the railroad is involved.
- There was a period in US history where dynamite was made illegal for the benefit of domestic nitroglycerine manufacturers - and thus needed to be smuggled to buyers…
- Offer the PCs the option of using elderly, sweaty dynamite … but allow them the relevant rolls to remember that that's not a good idea. Or make them roll to notice that the dynamite isn't "meant to be like that" if that suits your campaign better.
- For alternate history or late Steampunk, the dynamite gun might make good mainstream tech.
- Given its engineering uses the determined-homesteader might turn out to be surprisingly well armed and skilled in demolitions. In any case, this stuff will be cropping up down mines (and in DIY stores in some parts of the world) for years.