Naval Guns

Naval guns saw use not only on ships, but on seacoast defense fortifications on land, operated sometimes by naval crews and at other times by army heavy artillerymen.

The Union Navy was blessed with the ordnance creativity of Rear Admiral John A. Dahlgren, chief of'Naval Ordnance from July, 1862, to June, 1863, when he assumed a sea command. 1 lis first heavy iron gun design was submitted in 1850, and a 9-inch smoothbore was cast to his design at the West Point Foundry, The 9-inch tube, which weighed

The largest gun cast in the world to that date was this 20-inch Rodman gun mounted at Fort Hamilton, New York. It was fired only four times during the war. (Library of Congress)

9,000 pounds, was successfully tested and led to its production iti 10- and 11-inch (weighing 15,700 pounds) calibers as well. The weapon was designed specifically to lire shells into wooden vessels, but it was so strong that it was also capable of dealing with the increased charges fired into ironclads. In practice, the U.S. Navy used the 9-inch guns, which fired 70-pound shot, on broadsides, and the 11-inch guns, which fired 127-pound shot, for its pivot guns. The Dahlgren gun had an especially modern, smooth shape, leading British ordnance experts to dub them "soda-water bottles."

Dahlgren also designed 15- and 20-inch naval guns in 1862, These were cast at the Fort i'itt Foundry using tire Rodman system of cooling them from the inside. These tubes were lighter than the true Rodman guns, weighing 42,000 pounds as opposed to some 50,000 for the Rodmans. Their maximum diameter was 48 inches, and the bore length was 130 inches. They could Fire solid shot weighing 440 pounds, cored shot weighing 400 pounds, shells weighing 330 pounds, grape, or canister.

In 1KH4, the Navy had a 20-inch gun cast to Dahlgren*s design. It was 204 inches long with a bore 163 inches long. Its maximum diameter was 64 inches, and total weight of about 100,000 pounds. It would lire a 1,000-pound cored shot, taking a 100-pound standard charge. It apparently saw only experimental use, in which it was successful in breaking through the toughest iron plate available.

The Navy also ordered several 13-inch Dahlgren guns, which were cast in the standard manner, but they proved a failure, each exploding after onlv firing several rounds of solid shot. Versions cast in the Rodman style successfully fired over 500 cored shot rounds in experiments, hut they were never put into production, tire 15-inch being ordered for Monitor-class boats instead.

Additionally, some 10-inch Dahlgren guns were cast, as were 50- and 80-pounders. The 50-pounder first appeared in late 1861, while die 80-pounder appeared iir the middle of that year. The 80-pounders exhibited an alarming tendency to burst when firing, and were soon replaced, fire log of the U.S.S. Hetzel noted, on February 7, 1862: "At 5:15, rifled 80-pounder aft, loaded with 6 pounds powder and solid Dahlgren shot, 80 pounds, burst in the act of firing into four principal pieces. The gun forward of tile trunnions fell on deck. One third of the breech passed over the mastheads and lell clear of the ship on the starboard bow. One struck on port quarter. And the fourth piece, weighing about 1,000 pounds, driving through tire deck and

Seven Inch Dahlgren Pivot GunFort Monroe 1940s

Loading a 15-inch Rodman gun at Fort Monroe, Virginia. Note that a hoist is used to bring the solid shot to the muzzle, due to the heavy weight of the shot. {National Archives)

magazine, bringing up on the keelson, set fire to the ship." A handful of 15'0-pounders were also produced, Inil their quality was distrusted, and ihey never saw actual service.

Dahlgren himself was concerned about the safety of such large weapons, and ordered their use limited to fire against ironclads, and then with reduced charges. In action, in die turret of the U.S.S, Weehawken, a Monitor-class ship, a 15-inch Dahlgren/

Rodman gun, firing at full charge behind a 400-pound cored shot, smashed through the armor of the C.S.S. Atlanta at 300 yards. Although the Wrehawkm needed to fire only five rounds, with both iis 15- and 11-inch guns, ihe Atlanta, having run aground and being unable to bring its guns to bear, was forced to surrender due to the damage done by the large gun. These 15-inch guns, called Rodmans by the army and Dahlgrens In1 the navy, were also acquired by the army for its forts around Washington and along the seacoast.

The Union Navy also used 6.4-inch and 8-inch Parrott rifles that were essentially the same as the army models.

l lie Confederates came up with one unique piece of heavy rifled artillery of their own, the Brooke rifle. It was designed by a Confederate Navy officer, John M. Brooke, Chief of the Bureau of Ordnance and I lydrography. It was a last-iron gun using wroughtt-iron reinforcing bands around the breech. Different versions had different numbers of bands, ranging from one to three, with two being used on 7-inch to 10-inch guns. Rifling was similar to that of the British-made Blakely rifle, although Tredegar did cast one 7-iiich Brooke that they did not tille or band. In 1H62, Tredegar also cast a 7-inch Brooke rifle which it triple banded.

A 7-inch Brooke rifle could send a projectile more than four and a half miles. Many of these weapons were made at Richmond's Tredegar Iron Works, which produced 14 of them between September, 1861, and March, 1862. Their sizes were recorded at 6.4-inch, 7-inch, 8-inch, 10-inch, and 1 I-inch. Tredegar also described several Brooke rifles that they cast as "32-pounders."

The largest source of Brooke guns, however, was llie Confederate Navy itself. It set up its own naval gun foundry in Selma, Alabama, in 1863, casting its first 7-inch Krooke rifle in July, 1863. This gun was not acceptable, and the foundry lurnaces were rebuilt, its next guns were also failures, for various reasons, but by January, 1864, the foundry was able to supply its first 7-inch Brooke rifle to the C.S.S. Tennessee. Other Selma-cast Brooke rilles went to land fortifications, such as the defenses of Mobile, Alabama. The foundry also cast 10-inch and 11-inch Brooke guns for harbor defense. Selma-produced Brookes in 6.4- and 7-inch

Loading a 15-inch Rodman gun at Fort Monroe, Virginia. Note that a hoist is used to bring the solid shot to the muzzle, due to the heavy weight of the shot. {National Archives)

An experimental carriage for a Rodman gun tested at Fort Monroe, Virginia. The idea was to make for easy and accurate elevation. The system was never adopted. (Library of Congress)

were rifled, while die 8-, 10-, and 11-inch Brookes were smoothbores. Ail told, the fouridry produced 102 Brooke rifles and guns.

The Brooke turned out to be a very serviceable design, although prone to bursting more through manufacturing llaws than design flaws. On January 9, 1864, General RG.T. Beauregard wrote Colonel Josiah Gorgas, Chief of Ordnance, the results of experiments in ordnance tried ai Charleston, where he commanded: "Gen. Ripley, ih one of his reports, makes the following statement:

"The Brooke gun at Fort Sumter was fired with 15 pounds of powder aL 18 degrees elevation, and although the charge was less ihan the maximum it finally cracked through the veiit, and the gun was condemned. Happening to be present 1 ordered a reduction in using the remaining gun of the same kind, and better ranges were obtained with 10 pounds of mixed coarse-grained and common cannon powder.

"With 20 A degrees a shell of 100 pounds was thrown 4 miles into the enemy's camp, and with 23 degrees it was thrown beyond Light-House Inlet and on Folly Island."

Major-General Dabney Mann, in writing of tile defense of Mobile, noted: "But we had some cannon better than any Parrott had ever made. They were the Brooke guns, made at Selma in the Confederate naval works of the iron from Briarsfteld, Alabama the best iron for making cannon in the world.

"Our Brooke guns at Mobile were rifles, of 11 inch, 10 inch, 7 inch and

6 /in inch calibers. They outranged the Parrotts, and, though subjected to extraordinary service, not one of them was ever bursted or even strained."

Even so, as with all big gtins, Brookes were not immune to premature explosions if incorrectly used. Gblonel William Lamb; commander of Fort Fisher, wrote that during the final attack on his fort: "M\ two seven-inch Brooke rifles both exploded in the afternoon of this day. Being manned by a detachment of sailors and situated opposite to lite bar, I had given the officer in charge discretion to lire upon the vessels which had approached the bar, and his fire had been more rapid than from any other guns, and with the disastrous result of explosion, which unfortunately wounded a number of men."

Inch Dahlgren Smoothbore Naval Gun

Major Manigault noted on September 19, 186$: "Commended firing ... with 4.62 in. Rifle No. 1. Fired 7 Shots will) good effect when the rear Band of the piece showed symptoms of Starting from die one in front of it and the black, semi-liquid unctuous residuum from inflamed gunpowder oo/ed out from between the hands. Ceased firing from this gun, which must now be regarded as positively dangerous, and unfit for use. (Total Number of Shots fired from it by us 261, at an average elevation of 13 /ยป degrees, 4 lbs of Powder, and Average Weight of projecting probably 21 or 28 lbs.) The Vent is very much enlarged and quite ragged," This weapon, judgi of the "bands" was probably a Brooke rifle.

Was this article helpful?

+2 0


  • Kristian
    How are naval cannons cast?
    8 years ago
  • Samppa
    What ship is that big naval gun at fort hamilton,ny from?
    5 years ago

Post a comment