Dahlgren Boat Howitzer
Washington Navy Yard · Machine Gun · Out Of Production · 1849
Also known as: Dahlgren 12-Pounder Boat Howitzer, Dahlgren Boat Gun, 12-Pdr Dahlgren Howitzer
Overview
The Dahlgren Boat Howitzer is a bronze smoothbore muzzleloading boat howitzer designed by U.S. Navy ordnance officer John A. Dahlgren beginning in 1849. Built to arm the launches and cutters of warships and to support landing parties of sailors and Marines ashore, the iconic heavy 12-pounder model has a 4.62-inch (117 mm) bore, weighs roughly 761 pounds, and could be quickly shifted between a shipboard slide mount and a wheeled field carriage. In place of conventional trunnions it carries a mounting loop beneath the barrel, with an elevating screw running through the cascabel. The family included light, medium (heavy), and small 12-pounders, a rifled 12-pounder, and a larger 24-pounder, and the type saw extensive service throughout the American Civil War.
Specifications
| Weight (empty) | 345186 g (12176.1 oz) |
| Overall Length | 1295 mm (50.98") |
| Barrel Length | 1295 mm (50.98") |
| Action Type | Muzzleloader |
| Firing Mechanism | Percussion |
| Magazine Capacity | 1 rounds |
| Magazine Type | Muzzleloader |
| Muzzle Velocity | 300 m/s (984 fps) |
| Muzzle Energy | 244935 J (180655 ft·lbf) |
| Effective Range | 1100 m (1203 yd) |
| Maximum Range | 1620 m (1772 yd) |
| Rate of Fire | 2 rpm |
| Barrel Rifling | Smoothbore |
| Frame Material | Bronze |
| Barrel Material | Bronze |
| Finish | Bronze |
Calibers
- 12-Pounder (4.62 in) · primary — also known as 4.62-inch smoothbore, 12-pdr shell, 117mm naval
Features
- Firing modes: Manual
- Feed systems: Muzzle Loaded
- Features: Smoothbore Muzzleloader, Bronze Construction, Mounting Loop In Place Of Trunnions, Elevating Screw Through Cascabel, Boat And Field Carriage Compatible
Variants
- Dahlgren Light 12-Pounder Boat Howitzer — Lightweight
- Dahlgren Rifled 12-Pounder Boat Howitzer — Rifled
- Dahlgren 24-Pounder Boat Howitzer — Heavy Caliber
Service history
Operators
- United States Navy · adopted 1850 · as 12-Pdr Boat Howitzer
- United States Marine Corps · adopted 1850
- Confederate States Navy · adopted 1861
Conflicts
- American Civil War (1861-1865)
- Paraguayan War (1864-1870)
Production
Production years: 1849-1880
The U.S. Navy acquired during the Civil War alone roughly 456 medium 12-pdr, 177 light 12-pdr, 23 small 12-pdr, 124 rifled bronze 12-pdr, and 7 steel 12-pdr howitzers, plus 100 rifled 20-pdrs and 1,009 24-pdr boat howitzers.
Origin
Country of origin: United States
Designer: John A. Dahlgren
Discontinued: 1880
Notes
Classified here under a weapons category as a crew-served light naval gun; it is properly a piece of muzzleloading naval/field artillery rather than a small arm. Listed specifications are for the heavy 12-pounder smoothbore version cast at the Washington Navy Yard.
Background
In 1848 Lieutenant John A. Dahlgren was assigned to evaluate the Army's mountain howitzers for use aboard ship; dissatisfied with them, he developed his own family of light bronze boat howitzers that became standard U.S. Navy landing-party and small-boat ordnance through the Civil War.