MOBILE, Alabama - Construction of the USS Tulsa ship is approaching a milestone.

The USS Tulsa is being built by Austal USA in its shipyard in Mobile, Alabama. The Tulsa will be a Littoral Combat Ship, or LCS, part of the U.S. Navy's new class of ships designed to operate close to shore.

The Tulsa is known as LCS 16. It will be an Independent class version, meaning it will be 421 feet long, almost 104 feet wide and 104 feet tall. It is costing the Navy $350 million.

Austal USS laid the keel for the Tulsa in January. Its sponsor, former Tulsa mayor Kathy Taylor, is the ship's sponsor and as per tradition she welded her initials onto a plate that was attached to the keel.

Austal USA says the ship is being built by welding together individual modules. The Tulsa will have a total of 37 and so far 31 of them have been welded together. 

The first USS Tulsa was a gunboat that served until 1944. The second USS Tulsa was a cruiser whose construction was canceled at the end of World War II.

The Littoral Combat Ship program is a radical change in how the Navy builds, uses and mans its fleet. Because the ships have a shallow draft, they can operate very close to shore. They're also designed to carry minimal maintenance and repair equipment on board, instead relying on pre-scheduled maintenance periods and contractors who fly to the ship to fix major problems.

The Navy expects the Littoral Combat Ships to serve for 40 years.

The Tulsa is scheduled to be christened early next year and to join the Navy's fleet in 2018. It will look like the USS Omaha, a photo of which is attached to this story.