Monday, 18 June 2012

Great Balls of Fire

On the clifftops above Saint Brieuc, Brittany, is a curious stone structure. In fact, it is a reminder of naval warfare between Britain and France.

The device is a cannonball oven, intended to heat the missiles in the hope that they would set enemy ships on fire. Designed in 1794, it was staffed by five men. The first was responsible for the fire which burned in the left-hand part of the structure. Wood was fed in through the upper opening, while the lower provided ventilation. A third opening in the side wall allowed ashes to be removed. 

When the fire was going well, a load of 20 cannonballs would be sent down into the oven through an opening at the back. They rolled down three channels to a flat metal area where they would sit in a bowl for two-and-a-half hours until they turned red-hot. The process could be supervised from the upper right-hand opening. 

Once ready, the cannonballs exited by the lower opening. They were quickly carried in a large, metal 'spoon' to the nearby cannon, already prepared with a charge of gunpowder. It would be fired, and the hope was that if it reached its target then it would not only damage it, but set it alight.


Hels said...

Pretty nifty for a 1794 design.

I remember with much earlier battles, if they wanted to set enemy ships on fire, they had to set a fire boat alight and ram it into the enemy ship at sea. Heating the missiles might have been less precise, but at least it was warfare at a distance.

HughB said...

I recall from my Hornblower that the timing of the heating was fairly critical: not long enough and the balls wouldn't be hot enough, too long and they would start to lose their shape and get wedged in the cannon with disastrous results!

SilverTiger said...

I had no idea that such techniques were employed. Presumably, this was done only on land and not on board ships where fire would pose a danger and there would be little room for ovens.

I wonder how effective this method was as I imagine the balls cooled rapidly once removed from the oven.

Either way, the gunner would certainly merit the title of "hot shot"!

CarolineLD said...

The timing seems to have been critical, with the guns nearby and ready-loaded with gunpowder. I haven't found any information on how well the heated cannonballs worked though.

Hugh, I hadn't thought about the cannonballs getting too hot but that does explain why they were carefully watched through the opening.