Can the Navy afford to lose its biggest underwater missile magazines before a real replacement is ready? That question sits behind a growing problem in the U.S. submarine force. The Navy’s four Ohio-class guided-missile submarines have long served as stealthy conventional strike platforms, each able to carry 154 Tomahawk cruise missiles. As those boats head toward retirement, the service is not just losing old hulls. It is losing a rare ability to deliver a concentrated salvo from beneath the surface without putting surface combatants closer to danger.
The scale of that change is hard to ignore. The Ohio, Michigan, Florida, and Georgia were converted from ballistic-missile submarines in the 2000s, turning oversized Trident launch tubes into clusters that could fire large numbers of Tomahawks while still supporting special operations and intelligence missions. In practice, they became underwater arsenal ships. Their departure removes more than 600 cruise missiles at once from the fleet’s undersea strike inventory, a level of concentrated firepower that the Navy’s current replacement path does not fully restore.
The planned substitute is the Virginia-class Block V with the Virginia Payload Module. It is a meaningful upgrade, but not a one-for-one answer. A VPM-equipped Virginia carries about 40 missiles, not 154. That turns every retirement into a math problem as much as a force-structure problem, because several attack submarines are needed to match the punch of one retiring SSGN. That would be challenging even in a healthy shipbuilding environment. It is much harder in today’s one.
The Columbia class, which is supposed to replace Ohio ballistic-missile submarines in the strategic deterrent role, is already consuming industrial attention. The lead boat is now projected to be delivered 17 months late, and the broader submarine enterprise is still wrestling with labor shortages, supplier bottlenecks, and yard capacity. One estimate in the current debate points to a need for roughly 140,000 skilled workers across the industrial base. Even as construction moves forward and new facilities come online, the pressure on the system remains intense.
That is why the idea of a Columbia-based SSGN keeps resurfacing. The class is designed with 16 large missile tubes for Trident II ballistic missiles. In a conventional-strike configuration, those tubes could be repurposed to carry dense missile loads, potentially creating a submarine with 200 to 300 missiles on board. That would not just replace the Ohio SSGN concept. It would create the largest conventional strike submarine the Navy has ever operated, one built for penetrating defended waters and launching heavy salvos at long range.
Still, the concept runs into the same realities that created the gap in the first place. Columbia boats are expensive, strategically prioritized for nuclear deterrence, and difficult to build on schedule. Using that hull as a cruise-missile truck would place even more demand on an industrial base already struggling to produce enough submarines. It also cuts against the Navy’s preference for spreading firepower across more platforms rather than concentrating it in a few very large ones.
That leaves a narrower set of practical options: extend some Ohio SSGNs if material condition allows, accelerate VPM production, and keep developing large unmanned undersea vehicles as supplementary missile carriers. None of those choices fully recreates what the Ohio conversions offered. That is the point. Once those four boats leave, the Navy is not just retiring submarines. It is retiring a form of massed undersea firepower that took decades to build.
