The ironclad CSS Georgia was scuttled by its crew in 1864. Now the civil war wreck is to be raised and preserved to improve access to the port of Savannah

The US navy is preparing to send one if its premier diving teams to Georgia, to help salvage a Confederate warship from the depths of the Savannah river.

Before it ever fired a shot, the 1,200-ton ironclad CSS Georgia was scuttled by its own crew to prevent its capture by General William Tecumseh Sherman when his Union army took Savannah in December 1864. Today, it is considered a captured enemy vessel and is property of the US navy.

The shipwreck is being removed as part of a $703m project to deepen the river channel so larger cargo ships can reach the port of Savannah. Before the harbour can be deepened, the CSS Georgia has to be raised.

After years of planning, archaeologists began tagging and recording the locations of thousands of pieces from the shipwreck in January. They have been able to bring smaller artefacts to the surface, but the navy is being called in to raise the 120ft-long ship’s larger sections and weapons. Navy divers are scheduled to arrive at the site near downtown Savannah about 100 yards from the shore on 1 June.

The navy divers assigned to the project are from the same unit that has participated in some of the military’s highest-profile salvage operations. That includes the civil war ironclad USS Monitor, TWA Flight 800, Swiss Air Flight 111, as well as the space shuttles Challenger and Columbia.

Divers from the Virginia Beach-based Mobile Diving Salvage Unit 2 also provided damage assessments and repairs on the USS Cole following the terrorist attack on it in Yemen in 2000 and pulled up wreckage from an F-16 that crashed off the eastern shore of Virginia in 2013.

In Georgia, navy divers will pull up parts of the ship’s armor systems, steam engine components and small structure pieces. They will eventually be sent to one of the US Naval History and Heritage Command’s repositories and Conservation Research Laboratory at Texas A&M University in College Station, Texas.

“The desire to maintain the ship in somewhat of a conservable state is one of the primary concerns. That’s a little bit different from typical salvage. Oftentimes, aside from human remains or things like a flight data recorder, it’s simply object recovery. It’s bringing it up safely and disposing of it. Whereas these artefacts will be preserved for future generations,” said Chief Warrant Officer Jason Potts, the on-scene commander for the CSS Georgia operation.

The weapons, which include four cannons and about 50 projectiles that are either rifle shells or cannon balls, will be handled by explosive ordnance disposal technicians from Kings Bay, Georgia.

Potts said the weapons systems would be removed first, then divers would focus on the propeller and main shaft, portions of its steam machinery and large portions of the ship’s armoured encasement. The armor for the ship, which was anchored off Fort Jackson as a floating gun battery, was made out of railroad iron.

Archaeologists will still make sure there are no other remnants remaining after the navy divers leave at the end of July. Work to preserve and catalogue all of the individual artefacts is expected to take another year or more.