US Navy replaces Ohio-Class, the world's most heavily armed missile submarines: 19 Virginia-class boats become next- gen SSGNs to succeed them

The United States Navy has begun retiring the world's most heavily armed conventional missile submarines and is replacing them with a new generation of guided missile platforms, formally redesignating 19 planned Virginia-class submarines fitted with the Virginia Payload Module as SSGNs.The Navy announced the redesignation on 3 August 2026, one day after USS Georgia, the first of four Ohio-class guided missile submarines, began its inactivation process on 31 July 2026 after more than four decades of service.What is an SSGN and how is it different from an SSN?In US Navy nomenclature, submarines are named after American states, a tradition that also reflects their class and role.An SSN is a nuclear-powered fast attack submarine, built primarily to hunt enemy ships and submarines, gather intelligence, and support special operations. Virginia-class submarines, named after the state of Virginia, have carried this designation since the programme began.An SSGN is a nuclear-powered guided missile submarine, built specifically to carry and launch large volumes of cruise missiles for long-range precision strikes. The Ohio-class submarines, named after the state of Ohio, were converted from ballistic missile submarines into SSGNs in the early 2000s and have served in that role since.The distinction matters because it signals what the vessel is primarily built to do. An SSN hunts. An SSGN strikes.Ohio-class SSGN: the platform being replacedThe four Ohio-class SSGNs, USS Ohio, USS Michigan, USS Florida, and USS Georgia, were converted from ballistic missile submarines in the early 2000s at approximately one billion dollars per boat.Each Ohio-class SSGN is 560 feet long, operated by around 155 sailors, and carries 22 missile tubes. Each tube was large enough to hold multiple cruise missiles, giving every boat the capacity to carry and launch up to 154 Tomahawk land-attack cruise missiles. Across all four boats, that amounted to a combined theoretical capacity of 616 Tomahawks, making them the most heavily armed conventional strike submarines ever operated by any navy.Beyond missiles, each platform could accommodate more than 60 special operations personnel, with facilities for dry deck shelters capable of deploying and recovering special forces teams covertly. In a US Navy release published on navy.mil, Commanding Officer of USS Ohio Captain Andrew Hale described the platform: "While other submarines can carry Tomahawks and deploy special forces teams, the Ohio class SSGN can carry significantly more of both, and for a much longer sustained period."USS Georgia began inactivation on 31 July 2026. USS Ohio is scheduled to follow in the 2027 financial year, USS Florida in 2028, and USS Michigan in 2029. When the last of the four is retired, the Navy will have lost a combined launch capacity of 616 Tomahawks from four of the stealthiest platforms ever built.Virginia Payload Module: what it addsThe Virginia Payload Module is a 70-foot hull extension inserted into the midsection of Virginia-class submarines beginning with the Block V variant. It increases the submarine's total length from around 377 feet to 460 feet and raises submerged displacement to nearly 10,200 tonnes.The VPM houses four large-diameter payload tubes. According to the US Navy's Virginia-class fact sheet on navy.mil, each tube is capable of carrying seven Tomahawk land-attack cruise missiles, adding 28 missiles per submarine. Combined with the 12 vertical-launch positions already carried on standard Virginia-class boats, a VPM-equipped platform carries a total of 40 Tomahawks.The payload tubes are also designed to accommodate Intermediate-Range Conventional Prompt Strike hypersonic missiles, large unmanned underwater vehicles, seabed warfare systems, and other future payloads. Each submarine additionally carries four 533mm torpedo tubes capable of launching Mk 48 heavyweight torpedoes, anti-ship missiles, and other submarine-launched weapons.All Virginia-class submarines are powered by an S9G nuclear reactor, giving them virtually unlimited endurance, requiring resupply only for food and consumables. The VPM also restores the ability to host dry deck shelters for special operations, a capability that defined the Ohio-class platforms.Which submarines will carry the VPM?The lead Block V submarine, USS Oklahoma, is being built without the module. The second Block V boat, the future USS Arizona, will be the first to receive it. The remaining Block V submarines will follow, with the redesignation covering platforms across Virginia-class Blocks V and VI, totalling 19 submarines.The first formally designated SSGN under the new classification, SSGN 803, is expected to be delivered in the 2029 financial year. Deliveries are scheduled to continue through the 2038 financial year.What the Navy saysVice Admiral Rob Gaucher, Director of Submarine Programs, said the redesignation is "a clear acknowledgment of the increased lethality VPM brings to the undersea fight," adding that the new SSGNs would give fleet commanders "an incredibly versatile, hard-hitting instrument of national power."Chief of Naval Operations Admiral Daryl Caudle said the new platforms build on the Ohio-class legacy "with greater survivability, adaptability, and sustained combat power," and that they would "provide our Nation with a powerful and persistent deterrent" and "ensure the Navy remains ready to fight and win whenever and wherever called upon."Vice Admiral Rick Seif, Commander of Submarine Forces, said the new SSGNs would serve as "the ultimate enabler for Distributed Maritime Operations, giving our warfighters the overwhelming, flexible firepower required to win decisively in any theater."40 versus 154: how the numbers stack upThe gap between what the Ohio-class carried and what each Virginia-class SSGN will carry is significant. A single Ohio-class SSGN held up to 154 Tomahawks. A VPM-equipped Virginia-class SSGN will carry 40.However, the Navy plans to field 19 of the new platforms. If all 19 were operational simultaneously, their combined Tomahawk capacity would reach 760 missiles, exceeding the Ohio fleet's total of 616 across four boats. That number will not be reached until well into the 2030s at the earliest, given that the first delivery is not expected until 2029 and the last not until 2038.The Navy said the new submarines will retain the full stealth, sensors, and multi-mission attack capabilities of the Virginia class alongside their expanded strike role, and will remain, in the Navy's words, "an integral part of the storied Virginia Class program."