Low Tech cannons mortars and shells

[Varyon]

A bit of online searching indicates explosive cannon shells date to the 14th century, or late TL 3; apparently the earliest ones were cast from bronze. They were typically used by mortars* rather than the longer cannons, and had a lot of issues - they could get jammed, explode prematurely, fail to explode, etc, and you had to light them prior to shooting them out of the mortar. For simplicity, I'd probably just use the LE guidelines from High Tech, using the Malf typical of TL 3 (or TL 4, if later - or just use TL 4 stats outright, and assume the first ones that showed up were just a case of TL 4 gear showing up a bit early). Actually, given they were notoriously finicky, I'd probably apply a -1 to Malf, both for the mortar firing it and for the shell itself (they aren't as reliable as typical iron bombs). Or maybe have that first -1 only apply to cannons, with the shorter-barreled mortars not having much issue launching them.

*I honestly can't recall of mortars actually show up in LT - it might have only been longer cannon. ISTR at least one of the ridiculously-large weapons in LTC2 making a note that it would technically qualify as a mortar (the barrel was only a few calibers long, but it was one heck of a caliber), but I don't remember more appropriately-sized mortars actually being in LT.

[Rupert]

Originally Posted by Varyon

*I honestly can't recall of mortars actually show up in LT - it might have only been longer cannon. ISTR at least one of the ridiculously-large weapons in LTC2 making a note that it would technically qualify as a mortar (the barrel was only a few calibers long, but it was one heck of a caliber), but I don't remember more appropriately-sized mortars actually being in LT.

The definitions of 'mortar', 'cannon', 'gun', 'howitzer', and their hybrids are fairly arbitrary and differ from one country to another, and have differed over time as well. For TL3-5 using 'mortar' to mean 'an artillery piece that fires on a high arc, allowing indirect fire' and 'cannon' or 'gun' to refer to everything that doesn't do this is generally going to be fine if you're not trying to distinguish further.

[Polydamas]

Originally Posted by Rupert

The definitions of 'mortar', 'cannon', 'gun', 'howitzer', and their hybrids are fairly arbitrary and differ from one country to another, and have differed over time as well. For TL3-5 using 'mortar' to mean 'an artillery piece that fires on a high arc, allowing indirect fire' and 'cannon' or 'gun' to refer to everything that doesn't do this is generally going to be fine if you're not trying to distinguish further.

Its also generally harder to research early incendiary and low-explosive projectiles than solid shot. You can't just take shot mass, bore diameter, estimate muzzle velocity and call it good, and the tests are more dangerous.

GURPS Low Tech: Medieval China could be a fun supplement.

[Anthony]

Originally Posted by Polydamas

Its also generally harder to research early incendiary and low-explosive projectiles than solid shot. You can't just take shot mass, bore diameter, estimate muzzle velocity and call it good, and the tests are more dangerous.

You also have the problem that they don't leave very good artifacts for later archeologists. A shell that exploded isn't going to tell you much. A shell that failed to explode as designed might still explode later, or someone might remove it because it's a hazard. If none of those happens... plants think gunpowder is fertilizer, and an iron shell case isn't exactly the most weatherproof of components either.

[RGTraynor]

Originally Posted by Polydamas

GURPS Low Tech: Medieval China could be a fun supplement.

Agreed. It'd be eyepopping. Really, world history would be a whole lot different if the Song Dynasty was into aggressive conquest.