The US Navy has announced that future Virginia-class submarines equipped with the Virginia Payload Module (VPM) will be redesignated as guided missile submarines (SSGNs), marking a significant shift in how the service plans to employ its next generation of undersea strike platforms.Announcing the move, Vice Admiral Rob Gaucher, Director of Submarine Programs, described the redesignation as “a clear acknowledgment of the increased lethality VPM brings to the undersea fight.”He said the added payload capacity would allow the Navy to project greater strike power, deter adversaries, reassure allies and maintain undersea dominance for decades to come.The move comes as the US navy prepares to retire its four Ohio-class guided missile submarines (SSGNs), which currently serve as its primary conventional land-attack platforms. Each Ohio-class SSGN can carry up to 154 Tomahawk land-attack cruise missiles, making them among the world’s most heavily armed conventional strike submarines.The VPM is a 70-foot hull extension that contains four additional large vertical tubes designed to launch Tomahawk land-attack cruise missiles, Intermediate-range conventional prompt strike (IRCPS) hypersonic missiles, and other payloads. The move comes as the Navy prepares to replace the conventional land-attack role currently performed by its ageing Ohio-class SSGNs.The redesignation applies to Virginia-class submarines fitted with the Virginia Payload Module (VPM), beginning with the Block V variant. While these submarines will retain the stealth, sensors and attack capabilities of the Virginia class, they will now be officially classified as SSGNs (guided missile submarines) instead of SSNs (attack submarines) because of their substantially expanded strike capacity.The US navy currently plans to acquire 19 Virginia-class submarines equipped with the Virginia Payload Module (VPM), all of which will be designated as SSGNs. The first submarine in the fleet to receive the module will be the future USS Arizona, the second Block V boat under construction.The lead Block V submarine, USS Oklahoma, is being built without the VPM, while the remaining 10 Block V submarines are expected to be fitted with the module, significantly enhancing their missile strike capability.The VPM equipped Virginia-class submarinesThe module is a 70-foot (about 21-metre) hull extension inserted into the submarine’s midsection, increasing its length from around 377 feet (115 metres) to 460 feet (140 metres) and boosting displacement to nearly 10,200 tonnes when submerged. Powered by an S9G nuclear reactor, they have virtually unlimited endurance, requiring resupply only for food and other consumables.The VPM houses four large-diameter payload tubes, each capable of accommodating seven Tomahawk land-attack cruise missiles. This raises the submarine’s vertical-launch missile capacity from 12 missiles on earlier Virginia-class boats to 40 missiles, more than tripling its conventional strike capability. The payload tubes are also designed to support future weapons, large unmanned underwater vehicles (UUVs), seabed warfare systems and other mission-specific payloads.In addition to the 40 vertical-launch Tomahawk missiles, the submarines are equipped with four 533 mm torpedo tubes capable of launching Mk 48 heavyweight torpedoes, anti-ship missiles and other submarine-launched weapons.
