THE DAHLGREN BOAT HOWITZER

Perhaps one of the most versatile pieces of gunnery used by the US Navy during the Civil War was the Dahlgren boat howitzer. Designed by Capt. John A. Dahlgren of the Navy Ordinance Bureau, these were constructed with a bronze barrel and iron carriage. Two 12 pdr models were produced (a light and a heavy model) and a 24 pdr version as smoothbores. Rifled versions of the gun in 3.4” (12 pdr) and 4” (20 pdr) were also produced. Note the lack of trunions on the barrel (used on other field pieces to secure barrel to carriage). The barrel was secured to a fitting on the carriage by a removable bolt through a matching fitting on the bottom of the barrel. The barrel could be removed from the carriage and mounted on a similar fitting on the bow of a ship’s boat (Canney, pg. 176). The carriage could be disassembled and carried easily in the boat and by personnel on foot. In this way, the gun could be used on the boats for fire support during amphibious landings, then reassembled on land and transported by hand along with the attacking amphibious force to continue to provide fire support. Spencer Tucker referred to the Dahlgren boat howitzer as “undoubtedly the finest boat guns of their day in the world.” Boat howitzers were found in the arms complement of all US Navy ships, although they were not listed as part of the rating or official armament. On smaller ships, such as schooners and armed tugs, they could be used as the main deck guns.

NOTES ON ILLUSTRATION: The "live photo" of a Dahlgren boat howitzer is a replica owned and used by the Ft. Caroline National Monument in Jacksonville, FL. Part of their site includes the St. Johns Bluff area, which was a site of a significant naval engagement in Florida in the fall of 1862. The National Monument has a Civil War Living History event in November on the weekend before Thanksgiving to emphasize this element of the history of Jacksonville.

SOURCES
Donald L. Canney, Lincoln’s Navy. The Ships, Men and Organization, 1861-65 (London, UK: Conway Maritime Press, 1998), Chapter 11.

Spencer C. Tucker, Blue and Gray Navies. The Civil War Afloat (Annapolis, MD: Naval Institute Press, 2006), pp. 52-53.

Ibid, The Navy Dahlgren Boat Howitzer, Naval History Vol. 6, No. 3, 1992