Austal USA Launches Navy's Largest Floating Dry Dock in 40 Years

A Milestone Launch on the Mobile River

Austal USA has successfully launched the U.S. Navy’s Auxiliary Floating Dry Dock Medium (AFDM) 15, marking the first vessel of its type built for the Navy in more than 40 years. According to a report from The Maritime Executive, the launch on July 28 was also the largest vessel ever put into the Mobile Channel, and the biggest launch the company’s test and activation team has managed in Austal USA’s 26-year history.

At 12,000 tons and 694 feet in length, with a deck working area of 90,800 square feet, AFDM 15 dwarfs typical newbuild launches at the yard. The vessel was assembled at Alabama Shipyard before being moved to the launch dry dock on July 25, which was then flooded to float the dock into the river three days later.

Engineering and Logistics Behind the Launch

Getting a structure of this size safely into the water required close coordination across multiple disciplines. Austal USA credited its test and activation, crane and rigging, engineering, and AFDM program teams for executing the transfer and float-off, alongside support from the Navy, Alabama Port Authority Harbor Pilots, Alabama Shipyard, Berard Transportation, EN Bisso and Son Towing, and Crescent Towing.

Austal USA President Gene Miller called the launch a proud achievement for the company, noting that building the Navy’s first AFDM in four decades demonstrates the shipbuilding capability based on the Gulf Coast. He pointed to the strength of the partnerships involved and said the company looks forward to delivering an asset that will support the fleet for years to come.

What Makes AFDM 15 Different

AFDM 15 is a “Rennie”-type floating dry dock, built with continuous wing walls and multiple sectional pontoons that give it the buoyancy and stability needed to lift vessels clear of the water. It carries an 18,000 long-ton lifting capacity and a clear deck working area of 90,800 square feet, sized specifically to accommodate Navy destroyers and cruisers.

The dock measures 694 feet overall, with a pontoon breadth of 157 feet and a height of 65 feet from baseline to wing deck. Austal USA says the design draws on operational experience gained from owning and running a comparable floating dry dock at its own Mobile ship repair facility, incorporating changes intended to improve operability and long-term maintainability.

Why This Matters for Fleet Maintenance and Docking Capacity

For ship owners and operators outside the naval sector, the launch of a new large floating dry dock is still a notable data point. Docking capacity for large vessels—whether naval combatants or big commercial tonnage—has been a persistent bottleneck across the industry, and the addition of any new heavy-lift dry dock expands available options for scheduled dockings, hull work, and emergency repairs in the Gulf Coast region.

The project also underscores how much planning and physical infrastructure sits behind a single dry-docking event. A facility with an 18,000 long-ton lifting capacity is a serious engineering undertaking in its own right, and its arrival is a reminder that dry dock scheduling, condition assessments, and pre-docking surveys need to be planned well in advance given how limited large-capacity docking slots remain worldwide. Owners and managers preparing for upcoming dry-dockings should treat early condition and pre-docking surveys as essential, since availability at facilities capable of handling large hulls is not something that can be arranged at short notice. Accurate advance surveys help ensure that once a vessel does secure a dry dock slot, the time in dock is used efficiently rather than being extended by unexpected findings.

Looking Ahead

With AFDM 15 now in the water, the next phase will involve outfitting and testing before the dock is delivered for fleet service. Its completion adds a significant new asset to the pool of large-vessel docking infrastructure available in the U.S. Gulf region, at a time when demand for heavy-lift and large-hull docking capacity remains high across both naval and commercial sectors.

Reviewed by Ibrahim Halil Ceylan, Marine Surveyor at Apeks Marine.