Dahlgren Gun - Dahlgren Shell Guns

Dahlgren Shell Guns

Throughout the 18th and early 19th Century, the primary ship to ship weapon were muzzle loading smoothbore broadside guns firing solid shot modestly short distances. This all changed when the French Navy adopted a design of Col. Henri-Joseph Paixhans for a shell gun (canon-obusier) of 22 cm (8.7-inch) capable of throwing a 59 lb. shell in a reasonably flat trajectory (Gardiner 1992, p. 154). The U.S. Navy followed suit adopting the 8-inch, 63 cwt. Paixhans-style shell gun in 1841. Dahlgren was determined to design a new generation of shell gun that would be capable of firing explosive shells at higher velocity and greater range. They would also have the capacity to effectively fire solid shot. The ability to fire solid shot would become increasingly important as armored warships appeared on the scene:

Paixhans had so far satisfied naval men of the power of shell guns as to obtain their admission on shipboard; but by unduly developing the explosive element, he had sacrificed accuracy and range.... The difference between the system of Paixhans and my own was simply that Paixhans guns were strictly shell guns, and were not designed for shot, nor for great penetration or accuracy at long ranges. They were, therefore, auxiliary to, or associates of, the shot-guns. This made a mixed armament, was objectionable as such, and never was adopted to any extent in France... My idea was, to have a gun that should generally throw shells far and accurately, with the capacity to fire solid shot when needed. Also to compose the whole battery entirely of such guns. —Admiral John A. Dahlgren.

All of the Dahlgren shell guns were cast iron columbiads, had a distinctive soda bottle shape and all but two had an elevating screw running through the cascabel. Although some Dahlgren shell guns were tested to failure, no Dahlgren shell gun burst during service, a notable distinction for the time. Dahlgren shell guns were capable of firing shot, shell, shrapnel, canister, and (with the exception of the XV-inch shell gun) grape-shot.