Electric Boat receives new floating dry dock to support Columbia-class submarines

Naval News

By Ethan Gossrow

January 7, 2026




The new dry dock, designated “Atlas” was announced as received by General Dynamics Electric Boat’s primary shipyard in Groton, Connecticut in a LinkedIn post on January 4th. The primary purpose of Atlas is targeted towards supporting the construction of the Columbia-class of Ballistic Missile Submarines (SSBN) currently under construction.

Atlas was constructed by Bollinger Shipyards in Louisiana and completed the ~2,100 mile (3,380km) journey to Groton on January 3rd. The dry dock will be positioned directly next to the South Yard Assembly Building, the primary structure where assembly of the Columbia class of submarines takes place.

As detailed by GD Electric Boat, the dry dock stands at 618 feet long, 90 feet tall, and maintains a width of 140 feet. Atlas will sit 60 feet above the adjacent deck (40% of the total height of the South Yard Assembly Building), and can be aligned with either of the assembly bays when required. When not in use, the dry dock will be moored closer to the shoreline next to the building for storage. 

Construction of the Columbia-class

Since construction of the Columbia-class initiated 6 years ago, GD Electric Boat, Huntington Ingalls Industries, and Newport News Shipbuilding have continued to make steady progress towards the completion and delivery of the first boat, District of Columbia (SSBN-826), scheduled for October 2028.

Recently, the completed bow section of the District of Columbia was delivered in November of 2025, with the entire section transiting to Groton up the east coast via barge. The entire bow section is to begin testing and integration work ahead of the complete assembly of the first boat in the SSBN-826 class.

The future USS District of Columbia and her sisters have and will be built via a modular construction system, allowing for multiple sections of the boat to be constructed simultaneously across different manufacturers. The finalized bow section joins the stern, engine room, and finished propulsion components in completion, with all components delivered to GD Electric Boat ahead of final assembly and launching.

In total, the Columbia-class is projected to be a size upgrade compared to the aging Ohio Class of SSBNs, weighing in at 20,815 tons submerged with larger bean of 43 feet, even as the total SLBM allotment shrinks from 24 for the Ohio class boats to 16 on the Columbia. The District of Columbia is projected to cost just over $16 billion dollars in total when delivered, with each subsequent boat in the class shrinking in cost.

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