Civil War seacoast mortars were very large mortars used defensively in fixed fortifications and in coast and river defense. They were also used in siege operations and occasionally in other offensive endeavors. The largest mortar in the Federal arsenal was the 13 inch seacoast mortar, so named for the size of the weapon’s bore. Perhaps the most famous individual 13 inch mortar was one used at the Siege of Petersburg, Virginia in the summer of 1864. Union soldiers gave this weapon the nickname “The Dictator”.
Cast in a foundry in Pittsburgh, the Dictator weighed in at 17,120 pounds. Thirteen inch mortars were difficult to move due to their size and were transported by ships and by rail. At Petersburg, the Dictator was placed on a specially reinforced railroad flatcar and run along a spur line of the City Point and Petersburg Railroad into various firing positions. The flatcar also served as a firing platform.
The Dictator used gunpowder charges of 14 to 20 pounds to fire a 200 pound shell. The range of the mortar was 4235 yards when fired at a 45 degree angle of elevation, although one round is reported to have gone over 4750 yards. The flatcar recoiled 10 to 12 feet when the mortar was fired.
The Dictator was served by Company G of the 1st Connecticut Heavy Artillery Regiment and it went into action for the first time on July 9th. The Dictator lobbed shells into the city of Petersburg, but its primary target was a Confederate artillery battery across the Appomattox River called the Chesterfield Battery. “This 13 inch mortar was used principally against what was known as the ‘Chesterfield Battery,’ which from the left bank of [the] river, completely enfiladed our batteries on the right; all our direct fire seemed to have no effect. From this mortar was the only fire that seemed to hold the battery in check” wrote the regimental historian of the 1st Connecticut.
After firing five rounds on July 11th, the recoil of the mortar broke the flatcar it was sitting on, despite the flatcar’s reinforcement with iron rods and plates. The car was repaired and reinforced more, and the mortar returned to action.
During the Battle of the Crater on July 30th, the Dictator fired 19 rounds in support of the Union attack. One shell took out a cannon in the Chesterfield Battery, and another shell killed eight to ten men at the same location.
The Dictator remained in service at Petersburg though September, firing a total of 218 rounds. This unusual mortar on a flatcar arrangement also was a favorite subject of photographers covering the war at Petersburg, making it one of the more famous individual weapons of the conflict.
- Arms and Equipment of the Civil War by Jack Coggins. Mineola, NY: Dover Publications, Inc., 1990.
- History of the First Connecticut Artillery by John C. Taylor. Hartford, CT: Press of the Case , Lockwood, and Brainerd Co, 1893
- The Last Citadel: Petersburg, Virginia, June 1864-April 1865 by Noah Andre Trudeau. Boston, MA: Little, Brown, and Co., 1991.
- Staff Ride Handbook for the Overland Campaign, Virginia, 4 May to 15 June 1864: A Study in Operational Level Command by Dr. Curtis S. King, Dr. William Glenn Robertson, and Steven E. Clay. Fort Leavenworth, KS: Combat Studies Institute Press, 2009.
- The War of the Rebellion: A Compilation of the Official Records of the Union and Confederate Armies. Volume XL Part 1. Washington, DC: U.S. War Department, 1881-1901.