The Navy accepted delivery of the future attack submarine South Dakota (SSN-790) from General Dynamics Electric Boat earlier this week, marking the second-to-last Block III Virginia-class boat to come through the production line.
South Dakota is the 17th Virginia-class submarine built and is the seventh of eight Block III submarines. The final Block III boat, the future Delaware (SSN-791), will be delivered by Newport News Shipbuilding, which has a teaming arrangement with Electric Boat where they each build separate portions of the submarine and then trade off which company delivers the final product to the Navy.
“South Dakota’s delivery is an important milestone,” Capt. Chris Hanson, Virginia Class Program manager, said in a statement. “It marks the penultimate Block III delivery and will be a vital asset in the hands of the fleet.”
The 377-feet long, 34-feet wide Virginia-class submarine has a displacement of 7,835 tons. Virginia-class subs can travel at 25 knots and dive more than 800-feet below the surface, according to Electric Boat.
The Navy has pursued a block upgrade approach to its Virginia-class SSNs, with each new block-buy contract introducing into the program a new capability or manufacturing efficiency. The Block III submarines have two large diameter Virginia Payload Tubes, replacing what had previously been 12 individual vertical launch tubes. Each Virginia Payload Tube can launch six Tomahawk cruise missiles. The design change was done to cut the Virginia-class program’s per-hull cost without diminishing the submarine’s warfighting capability, according to a Naval Sea Systems Command statement. Virginia-class subs also carry Mark 48 advanced capability torpedoes.
“Delivering South Dakota is a significant achievement that represents the hard work and excellent performance of our shipbuilders, helps the Navy meet its shipbuilding goals and contributes to the nation’s defense,” Jeffrey Geiger, Electric Boat president, said in a statement.
Electric Boat is already building the Block IV Virginia-class submarines, and during the second quarter of this year, the Navy awarded General Dynamics $225 million to purchase long-lead materials for the Block V submarines, according to company statements previously reported by USNI News.