CHARLESTON, S.C. -- Scientists at the same lab where the Confederate submarine H.L. Hunley is being restored announced Friday they have finished conserving two guns from the famed Confederate naval raider CSS Alabama.

One of the 5-ton guns was shipped to Mobile, Ala., on Thursday, where it will be displayed at the Museum of Mobile.

The second remains in Charleston where there are plans to display it at a museum that will one day display the Hunley, said Paul Mardikian, the head conservator on the Hunley project.

The Hunley, the first submarine to sink an enemy warship, was raised off the South Carolina coast in August 2000, and brought to the lab. The next day one of the Alabama guns arrived as well. The second gun arrived some months later.

Initially, scientists had their hands full with the Hunley, the hand-cranked sub that contained the remains of its eight-man crew, so conservation work on the guns didn't begin until about six years ago.

"It's a relief for me to see them done," Mardikian said Friday. "Cannon are inherently difficult to conserve and stabilize. I would think these are the last cannon I treat with conventional techniques. It takes less time to build a bridge than to treat a cannon."

The conventional method leaves the cannon in a bath of solutions such as sodium hydroxide or sodium bicarbonate to remove salts left by salt water.

Clemson University researchers at the lab have been experimenting with a new subcritical fluid method. In such technology, fluids take on the characteristics of both a gas and a liquid under intense heat and pressure and have unique dissolving characteristics.

Mardikian said that once the technique is perfected, conserving a similar cannon in subcritical fluids could be done in six months rather than six years.

The Alabama, built in Liverpool, England and launched in 1862, was one of the most successful raiders in naval history.

The CSS Alabama Association says that during the 22 months it sailed, her crew boarded 447 ships taking 2,000 prisoners. The cannon have inscriptions showing they were made in Liverpool, Mardikian said.

The Alabama sank in about 200 feet of water off Cherbourg, France after an engagement with the Union's USS Kearsage on June 11, 1864, just a few months after the Hunley sank.

The wreck of the Alabama was discovered in 1984 by a French navy mine sweeper. The cannon were raised in 2000, a few months before the Hunley.

The 40-foot Hunley rammed a spar with a black powder charge into the Union blockade ship Housatonic on Feb. 17, 1864 off Charleston Harbor. Though it was the first sub to sink an enemy warship, the Hunley sank as well.

Learn more about the ships: Museum of Mobile, and Friends of the Hunley