Austal USA starts construction of Navy floating dry dock

Austal USA shipbuilders get set to start work on the shipyard’s third steel construction project

Construction is now underway at Austal USA on the Navy Auxiliary Floating Dry Dock Medium (AFDM) awarded the Mobile, Ala., shipyard under a $128 million June 2022 Naval Sea Systems Command contract. The AFDM is the third program to begin construction on Austal USA’s state-of-the-art steel assembly line following T-ATS 11 and 12 — the first two of four U.S. Navy Towing, Salvage, and Rescue (T-ATS) ships the company is under contract to build.

“This dry dock will be a first for Austal, but we’re up to the challenge,” said Austal USA vice president, new construction Dave Growden. “Our talented shipbuilders are always ready for whatever we require of them whether it’s the fourth ship in a multi-ship program or the first of a new design.”

The Navy floating dry dock is a “Rennie”-type floating dock which means it has continuous wing walls and several sectional pontoons to provide the stability and displacement required to lift and submerge vessels from the water using buoyancy. It has a 18,000 LT lifting capacity and a clear deck working area of 90,800 square feet. It has an overall length of 694 feet, overall pontoon breadth of 157 feet, and a height of 65 feet from baseline to wing deck. The vessel design incorporates features to improve operability and maintainability based on Austal USA’s experience and lessons learned from owning, operating and maintaining a similar dry dock at its Mobile, Alabama, ship repair facility.

• Historical note: Rennie, or pontoon type, floating docks have been around quite a while, we were writing about them back in 1911.