The Civil War Connections Blog

Bigger Isn’t Always Better

Hello readers, and welcome back to the good ol’ blog! Today’s tidbit about me is: when visiting Cambridge, we got to explore the Great Court at Trinity College. It’s a tradition that running-minded athletes try to round the entire Great Court in the time it take the College’s clock to chime the hour of 12 o’clock. In the film “Chariots of Fire,” one of the main characters completes this run early in the movie, which is a big deal because very few people have ever been able to finish in time. The title song from that movie is played frequently at the 2012 Olympics, especially during medal ceremonies.

Trinity College’s Great Court.


Some of you may remember my first few blog posts, where we explored the developing science of ironclad ships and armor-piercing cannons. In my third post I mentioned that the British and United States both were testing the effectiveness of cannon shells against ironclad armor in the spring of 1862. The parameters of their tests were as follows: they fired both 100 lb and 150 lb cannon shot at around 50 meters distance, and the shots successfully penetrated 4.5 inches of armor backed by 18 inches of teak wood. This armor thickness was exactly the same as that of the best ironclad in the world at that time, the HMS Warrior.



Well, 150 years ago readers of the Scientific American were treated to an even bigger display of armor-piercing firepower: in England, they upped the experimental ante by shooting against armor plates on a much grander scale. Instead of a 100 lb or 150 lb gun, they used a gigantic 300 lb one! They increased the armor plate as well, from 4.5 inches to 5.5 (although they reduced the teak backing from 18 inches to 9.) They also moved the target further away: to 200 meters instead leaving it at 50.

These are the Cliffs of Moher in Ireland. That’s a 200 meter drop… not very far for a cannon, but I wouldn’t want to dive off of that.


Despite the ridiculously large size of the gun they were using, the first shot didn’t get through the teak. The second and third shots did, but on the fourth shot the weapon “malfunctioned.” And by “malfunctioned” I mean the breech blew out of the cannon and flew about 40 yards to the rear, which pretty much ended the test. See, the 300 pounder they were using was an Armstrong gun – aka, a breech-loading cannon designed by Sir William Armstrong. This breech-loading design was safer to operate, and it allowed the gun barrel to be heavily rifled so as to make the projectile it shot a lot more accurate. The problem was that the breech-loading design was developed for normal field cannons, which were only 12-20 pounders. Any size bigger than that, and the inventor couldn’t guarantee the safety of the gun. The British government must have had a good laugh at that last sentence because the 300 pounder used as the test was an absolute beast. The Americans never made a Dahlgren gun bigger than 150 lb, because even the 150 lb model was awkward and impractical as all get out. In addition, Dahlgren was concerned about the gun blowing up: had the British paid attention to similar concerns voiced by Armstrong, maybe they wouldn’t have blasted the breech out of their giant cannon.


Those are 300 lb Armstrong guns. Just imagine them blowing up… *shudder*


Despite the technical success of this test, it’s pretty clear that ironclad armor was still very difficult to defeat. Even with a projectile far larger than any available in combat, armor plate was able to stop it at a relatively close range of 200 meters. The breech being stripped from the cannon probably didn’t help things either. By the end of the US Civil War the British were considering a different cannon model for their armed services, since the Armstrong gun – though safe and accurate – was also expensive, complicated and required a lot of maintenance. Rifling wasn’t unique to the Armstrong since the Union used Parrot rifled cannons extensively during the Civil War, and they were accurate at about 1-2 miles. The Parrot was muzzle-loading cannon, which was cheaper to make, maintain and provide for than a breech-loading model. Also, muzzle-loading guns were simpler to use and required less experienced crews to operate. For these reasons, the British stopped buying Armstrong guns at the close of the US Civil War.


A 110 lb Armstrong Gun from the HMS Warrior. Cannons usually weren’t much bigger than this, unless they were in a fort.


That just about does it, folks – tune in next time for more Civil War coverage, and in the meantime see if you can hear the “Chariots of Fire” song in the 2012 Olympics coverage!