Low Tech cannons mortars and shells

[stranger38]

Originally Posted by Rupert

Explosive shells were fired from mortars, which date from early 15th century Korea and had reached Europe by the mid-15th century. That'd make mortars a TL4 invention. However, at that time they were firing stone balls, though shells did come into use soon afterwards.

As for why nobody used shell in cannons, there are a few reasons. Firstly, until the early 18th century (TL5), the fuses were lit by hand and then the gun fired, and doing this with a long barrel cannon wasn't practical. Secondly, cannons were a lot more powerful than mortars and had a non-zero chance of detonating the shell's charge upon firing. Thirdly, the fuses time-setting was terrible, and that meant with a cannon that the shell was probably nowhere near the target when it went off, but with a mortar firing on a very high arc the shell wouldn't move far from its impact point.

Now, all of these things were solved over time - it was found that fuses would ignite from the flash of firing even if the shell was placed fuse-forward in the gun (the other way round and the flash might get into the shell and set it off instantly), but this was a TL5 discovery. Making this work in a cannon required a wooden sabot to hold the shell during ramming and firing (which also help cushion the impact of firing), another TL5 invention. Better powders made the shells less likely to blow up when they shouldn't - also TL5 and even TL6.

However, that still left the unreliable timing of the fuse, and that wasn't solved until late TL5 and into TL6 (and even TL7), and unlike all the previous innovations this is not something you can back-port to TL4 (though making decent quantities of TL5 gunpowder probably requires that you uplift some parts of the place's industry to TL5 anyway).

So, short answer is yes, and long answer is "they kinda use them"