Tuesday, December 29, 2009

Cannons and Gorns

This isn't strictly pirate-related but pirates are always interested in cannons. Mythbusters just showed an segment based on the "Gorn" episode of Star Trek. In this the Enterprise pursues a ship manned by the alien race the Gorn into an unknown system. Powerful aliens in that system transport Kirk and the Gorn captain to a planet to finish their fight one on one. They promised that a weapon would be available. Kirk eventually realizes that the weapon is the raw materials for a gun - sulfur, charcoal, saltpeter, hollow piece of a bamboo-like tree, and diamonds. He gathers the ingredients, mixes the gunpowder by hand, stuffs it all down a piece of bamboo with diamonds as projectiles, and sets it off. The result is enough to knock the Gorn off his feet long enough for Kirk to hold a knife to his throat and win the contest.

So, could this work? The Mythbusters found that bamboo makes a poor cannon and would injure Kirk more than the Gorn. Assuming that the alien bamboo is sturdier than the earthly variety, what about the gunpowder? The Mythbusters used the best of 30 trials. When they tried this in a modern cannon it barely pushed the ball out of the barrel so they gave up and switched to commercial powder.

Obviously, they did something wrong. In the GAoP, gunpowder came two ways, serpentine and corned. Serpentine powder was used for cannons. It is exactly what the Mythbusters used - the three ingredients mixed together by hand. Over time these would settle out so gunners had wooden paddles or scoops that they would use to remix the powder before use.

Corned powder was used in small arms and is what is sold today. This is serpentine powder that has been wetted and baked into cakes then ground up into grains (corns). In period, urine was often used for wetting the powder.

So what happened on Mythbusters? Serpentine powder burns slower so they would have needed wadding in their cannon to assure a good seal. They did not use this which is probably their problem. A longer barrel would have helped, also. Period cannons were quite long. That gives the powder longer to burn. It is also possible that they got the proportions of the powder wrong or didn't mix it properly. The best powder is 75% saltpeter, 15% charcoal, and 10% sulfur. That comes out to 15 parts, 3 parts and 2 parts. If they measured like Kirk did, then they just estimated by eye.

How does this relate to the Star Trek episode? Kirk measured his powder by eye while the Gorn was approaching. We didn't see Kirk use wadding in his cannon. Chances are pretty good that, in real life, his results would have been worse than the Mythbusters. On the other hand, if he remembered the right proportions and used a measure and wadding (and his bamboo barrel didn't explode in his face) then it would have worked.

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