Tall Ships Often Carried Cannons
Several of the tall ships that came to toronto for the Redpath Waterfront Festival 2013 had cannons. At interval, several were fired to the delight of visitors. I was in the front row!
SS SØRLANDET had a small brass cannon that came out when they were on display.
For a list of the ships see my page on the Tall Ships.
SS SØRLANDET had a small brass cannon that came out when the ship was on display. On the left is the little brass cannon ready to be fired. The fuse can be seen.
Black powder is used as the propulsant. In this cannon, it gets poured in the cannon through the hole where the fuse is (The vent). Other cannons were loaded from the mouth. The sailor then added a wad of paper through the mouth.
A fuse was inserted and after shooing all of us off to a safer place, the fuse was lit. After a few seconds the powder was ignited and there was a great noise and lots of smoke. They were not using a cannonball. I heard his say that if he wants a good display with lots of sparks and smoke he will add sawdust along with the wadded paper.
Firing the cannon. Fire and sparks escaping from the vent hole as well as from the mouth.
Brass (and Bronze) were used to make cannons as well as Iron. Brass was more flexible and could take the shock of the explosion. Iron was stronger but could fail and shatter without warning because it is more brittle.
Black powder is a very old mixture originally developed by the Chinese for fireworks.
Black Powder or just Powder is a mixture of charcoal, powdered sulfur and saltpetre (potassium nitrate). There were many methods of finely powdering the ingredients including ball mills and various grinding wheels made of non sparking materials. In some methods the saltpetre and charcoal were mixed wet. This allowed for better mixing since the salt solution actually penetrated into the charcoal.
I remember an episode of the MYTHBUSTERS where they made black powder but it was not all that great. Having done some research on it I don't think they ground the ingredients finely enough.
Several different types of charcoal were tried and some were much better than others. Alder, buckthorn, cottonwood and willow were all favoured.
Any spark making tool was avoided and powder was often manufactured and stored away from people.
Seen with people the cannon is really quite small. A small amount of powder makes a substantial explosion though.
Cannon balls were usually round balls made of iron. At first round stones were used but iron replaced stone.
Not all projectile were round balls. Other shapes were tried such as 2 balls connected with chain or an iron bar as well as variations of shapes. ON the left is a picture I took in the Smithsonian of a Cannon Bar shot taken off the Philadelphia gun ship. Round balls were more accurate but other shapes did more damage to rigging and sails and were used at close range.
Longer cannons were more accurate than shorter ones. Around the middle 1800's it was discovered that making helical grooves in the bore of the cannon gave the ball a spin and this improved accuracy.
Aiming the cannon was done using blocks and ropes. The cannon could weight many hundred pounds. This cannon has an attachment at the front of the little cart which allows the cannon to pivot around the opening. You can see the hinged door which is kept closed when the canon is not in use.
One cannon required a surprisingly large team of operators. Before the cannon could be fired it needed to be cleaned out with a wet sponge in case embers were left from the previous firing. The powder would be placed in, a wad of paper or straw tamped in, a cannon ball inserted and tamped, a fuse inserted in the vent. The cannon needed to be aimed and every 10 or so shots, needed to be cooled using wet sponges. People would also be needed to keep the cannon supplied with powder and cannon balls.
The angle of the cannon was important. The greater the angle of shot, the greater the range, at the cost of some accuracy. The angle was determined using a plumb bob type of apparatus.
All this was done in cramped often dark areas, full of smoke, on a moving ship.
Ropes and blocks were used to control recoil and to aim the cannon.
Controlling recoil increases the effectiveness of the cannon. The less energy used in moving back the cannon in recoil, the more energy is transferred to the ball. In practical terms this means fastening down the cannon and building it heavier.
The wall of the cannon is thickest around the chamber where the powder is exploded and great pressure is created pushing the cannonball out. The bore is the same size throughout but the thickness of the wall increases at the chamber and at the muzzle.
Cannons of this period are loaded through the muzzle. This includes the cannonball. They are sized to pass into the cannon easily but not allow too much space which would reduce the pressure as expanding gasses get around the cannonball.
Some gasses escaped though the vent where the fuse was inserted but this has a minimal impact. Take a look at the firing cannot at the top and you can see fire coming out of the vent.
Wikipedia article on gunpowder They also have a page on cannons.
I try to be accurate and check my information, but mistakes happen, especially to me. This information is provided for entertainment purpose. Don't go building cannons or firing them without talking to an expert.
email me if you find mistakes, I'll fix them and we'll all benefit: Christine