Monday, October 24, 2011

Cannonball Fragment Update

I was finally able to get a positive ID on the large iron piece found at the Battle of Bentonville a few days ago.  We suspected that it might be a cannonball fragment, but there was one thing that concerned me about it.  The fragment I found is obviously rounded on the outside, but the inside doesn't have the same curvature.  This is unlike most cannonball fragments I have seen in the past, which have a uniform thickness and equal curvature on the inside and out as seen in the cannonball example below.  The center would be filled with gunpowder, and a timing fuse placed in the hole would cause the cannonball to explode, sending several large pieces into the massed enemy soldiers.

In late 1862, Confederate Capt. John W. Mallet designed a new type of "internally segmented" exploding round ball which used a polygonal cavity inside the ball instead of a spherical one.  When the fuse ignited the gunpowder, the shell would fragment at the weak points in the shell wall producing a larger number of smaller fragments, which was meant to increase the damage to enemy troops.  The resulting fragments are rounded on the outside, but flat on the inside.  Each fragment will have a uniform shape determined by the geometry of the polygonal cavity, the most common being a pentagon shaped fragment.  This is the fragment I found, and a cross-section of a complete polygonal cavity shell is shown below.

The polygonal cavity cannonball was used exclusively by the Confederacy, and is fitting with the location it was found - alongside a line of fired confederate bullets at the site of a Union advance.  This type of shell was used only later in the war, and was the most commonly used Confederate cannonball in the 1865 Carolinas campaign.  Recall that the battle of Bentonville took place in March of 1865.  The complete ball measured 4.62 inches in diameter, and would have been fired from a smoothbore Napoleon 12 Pounder cannon, shown below.

With all of that history in technical terms above, it's sometimes necessary to step back from the academics and think about a recovered artifact in more personal, human terms.  It's hard to image the devastation that such a large exploding fragment could cause to the human body.  It's hard to imagine the fear of stepping out from the woodline and walking across that field, shoulder to shoulder, with rifles firing at you and shells exploding overhead.  It's hard to imagine the courage, on both sides of the battle, of risking and often losing life and limb to defend what you believe is right.  It is hard to imagine that this piece of iron which I hold in my hand was fired with the intention of taking another human life, and it is entirely possible that it was successful in doing so.  It is truly a humbling experience.

Special thanks to TheCannonballGuy over at TreasureNet for help in researching this article.


  1. Interesting. So was the fuse that went into the cannonball separate from the fuse that ignited the explosive to propel the cannonball out of the cannon?

  2. When I dig up unique items, I often think of the story that went along with it. How did it get here? Who did it belong to? I think that's another one of the fun things about this hobby!

  3. Awesome post. This hobby would be just another hobby were it not for the human connection that we make with those in the past. Very cool!

  4. @Steve,
    Short answer: yes.
    A primer ignites the cannon's gunpowder which powers the ammunition and simultaneously ignites the shell's timer fuse. The timer fuse explodes the shell after the set time.

    Long answer:
    To fire the cannon, the gunner pulled the long cord on a friction primer. The friction primer material ignited the gunpowder charge inside the cannon, which powers the ammunition forward.

    There were four main types of ammunition used during the Civil War: Solid Shot, Canister Shot, Case Shot, and Shells.

    Solid shot is what you typically think of as a cannonball - a big iron projectile that smashes what it hits. Canister shot is a cylinder filled with lead balls fired at short range - think of a giant shotgun. Case shot is a thin walled projectile filled with lead balls and a timer fuse, which explodes in the air above troops, raining lead bullets down upon them. Shells are thick walled projectiles filled with gunpowder and a timer or concussive fuse, and the destructive power comes from the fragments of the shell when it explodes. The fragment above is from an exploding shell.

    The fuses used in the ammunition itself are either concussion/percussion (ie detonates on impact) or timed fuses. Most timed fuses are based on paper cylinders packed with slow burning gunpowder, cut to length for the appropriate time, and held in a wood or metal fuse plug in the side of the shell. When the primer ignited the gunpowder to power the ammunition forward, it also lights the slow-burning fuse, which burns down over time to finally ignite the gunpowder *inside* the shell which explodes.

    I hope that was clear, and not too much information!

  5. @Rosie, yes i know what you mean! This goes on the short list of items I've found that I can say for sure "this is what it is, who it was from, what it was for." I have some others with interesting stories of who owned them, but I'll be telling those stories when it's January and too cold to go out and find new stories to tell!!

    @pulltabminer, we'll turn you from coinshooter to relic hunter yet, you just wait. ;)

  6. Tony, thanks for the Cannon Ball 101 info.