Dahlgren gun

Dahlgren's design philosophy evolved from an accidental explosion in 1849 of a 32 lb (14.5 kg) gun being tested for accuracy, killing a gunner.

Because of their rounded contours, Dahlgren guns were nicknamed "soda bottles", a shape which became their most identifiable characteristic.

In 1849, then-lieutenant Dahlgren began to design a family of smoothbore muzzle-loading boat howitzers that could be mounted in ships' launches and cutters as well as onto field carriages.

All of the boat howitzers were very similar in design, cast in bronze, with a mounting lug or loop on the bottom of the barrel instead of trunnions, and an elevating screw running through the cascabel.

Having the single mounting lug expedited moving the howitzer from the launch to field carriage and back.

No limber was used in naval service, but two ammunition boxes (each containing nine rounds) could be lashed to the axle of the field carriage.

The unit had trained on boat howitzers while deployed at Washington D.C., and when called to Bull Run, brought two of them along.

During the Antietam Campaign, Whiting's Battery (Company K, 9th NY Infantry [Hawkins' Zouaves]), employed five Dahlgren boat howitzers (two rifled, two smoothbore, and one of indeterminate type).

The Confederate Grimes' (Portsmouth) Battery had two smoothbore Dahlgren boat howitzers, with which they fought near Piper's Stone Barn (Johnson & Anderson, p. 78).

The New York Marine Artillery was issued twelve 12-pounder rifled boat howitzers made by Norman Wiard out of semi-steel, a low-carbon iron alloy.

The Indiana Brigade used a Dahlgren boat howitzer in fighting near Grand Prairie, Arkansas, on July 5, 1862.

Overall Charge (yards) Made Throughout the 18th and early 19th centuries, the primary ship-to-ship weapons were muzzle-loading smoothbore broadside guns firing solid iron shot short distances.

The U.S. Navy shortly followed suit, adopting an 8 in (203 mm), 63 cwt (2,858 kg) Paixhans-style shell gun.

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....

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.All of the Dahlgren shell guns were cast iron columbiads, with a distinctive soda bottle shape, and all but two had an elevating screw running through the cascabel.

This is not accurate, particularly for the VIII-inch Dahlgren, as a new iron carriage with an elevating screw beneath the breech of the gun was developed for VIII-inch (Department of the Navy 1866, p. III/66) and other carriages with breech elevating screws were also used (Department of the Navy 1866, p. I/83).

These guns would most likely have been intended for small riverine and estuarine gunboats, which the navy scrapped as quickly as possible after the war.

Also, in February 1867, Cyrus Alger & Co. paid a royalty on the Dahlgren patent for production of "ten eight-inch guns weighing 64,270, $642.70."

X-inch Dahlgren shell gun (light): 10 were cast at Seyfert, McManus & Co. and West Point foundries between 1855 and 1864.

Designed from the beginning to fire shot against armored ships with heavier powder charges.

XV-inch Dahlgren shell gun (short or Passaic): 34 were cast by the Fort Pitt Foundry between 1862 and 1864 (Ten Brink 2000).

[4][5][6] XV-inch Dahlgren shell gun (long or "Tecumseh"): 86 were cast by the Alger, Fort Pitt, and Seyfert, McManus & Co. foundries between 1864 and 1872 (Ten Brink 2000).

[7] The new XV-inch gun was lengthened 16 inches so that the muzzle was flush with the outside of the turret when fired, eliminating the need for the smoke-box, Carried on later Canonicus-class monitors.

XX-inch Dahlgren shell gun: four were cast by the Fort Pitt Foundry between 1864 and 1867 as part of the original planned armament for USS Puritan.

All of his earlier shell guns had been cast solid, then had the bore drilled out—the traditional way to make artillery.

In February 1862, Dahlgren recommended that the first 13 cast at Fort Pitt be withdrawn because the iron was inferior.

USS Hetzel, a converted Coastal Survey ship armed with one IX-inch Dahlgren and one 80-pounder Dahlgren rifle was engaged in the bombardment of Roanoke Island in support amphibious landings, when the following entry was made in her log for February 7, 1862: "At 5:15, rifled 80-pounder aft, loaded with six pounds powder and solid Dahlgren shot, 80 pounds, burst in the act of firing into four principal pieces.

And the fourth piece, weighing about 1,000 pounds, driving through the deck and magazine, bringing up on the keelson, set fire to the ship.

Although the test firing was successful the guns were not placed in service, because Dahlgren doubted the quality of the iron.