The Navy is looking at options to keep the Columbia-class submarine production line hot past a 12th boat and diversify what is loaded into the Virginia Payload Module, the service’s Director of Undersea Warfare said Thursday,

The Navy’s 12 Columbia-class nuclear-armed ballistic missile submarines (SSBNs) are set to replace the current 14 Ohio-class SSBNs that provide the sea leg of the U.S. nuclear weapons triad. The Columbia boats will carry 16 Trident II-D5 missiles armed with W76 nuclear warheads while the Ohio boats carry 24.

An artist's rendering of the U.S. Navy's future Columbia-class submarine. (Photo: U.S. Navy )
An artist’s rendering of the U.S. Navy’s future Columbia-class submarine. (Photo: U.S. Navy )

The Ohio-class submarines are planned to start retiring in 2027 while Columbia-class boats are scheduled to start patrols in 2031 to prevent a capability gap.

“There really is no margin for the Ohio to Columbia transition,” Rear Adm. John Tammen, Director of Undersea Warfare (N97), said at the Navy Submarine League’s annual symposium.

The Navy estimates it will cost about $130 billion to build the 12 Columbia-class submarines.

On Wednesday, Adm. James Caldwell, head of naval reactors, told the symposium construction on Columbia would start in 2021 but the Navy will have to work through problems to make sure they patrol by 2031 (Defense Daily, Nov. 7).

Tammen echoed a point made by Vice Adm. Johnny Wolfe, director of Strategic Systems Programs, that while the Nuclear Posture Review (NPR) called for at least 12 Columbia-class submarines, that is not a hard limit.

The NPR “says at least 12 or minimum 12. What we’re going to do is we’re going to keep the Columbia line hot after the 12th Columbia is produced.”

That way the Navy can procure additional Columbia boats if Strategic Command (STRATCOM) decides the U.S. actually needs more vessels. If STRATCOM keeps the tally at 12, Tammen said “we’re looking at what we call the modern large volume post platform” where the Navy adds the ability to host vehicles onboard inside the submarine’s center payload section.

However, Tammen noted “we haven’t nailed down the concept” for the large volume host platform.

These options mean “depending on what happens in the strategic environment we have two paths forward on the Columbia line,” he added.

Before the Ohio SSBNs are replaced the Navy will first extend their service lives from 30 to 42 years. Although Tammen said the Navy has never extended a submarine’s life to 42 years, it is preparing for the task by studying the first four Ohio-class submarines converted into Tomahawk cruise missile submarines (SSGNs) in the 2000s.

USS Washington (SSN 787), a Virginia-class submarine, completing initial sea trials. Photo: Ashley Major/Huntington Ingalls Industries.
USS Washington (SSN 787), a Virginia-class submarine, completing initial sea trials. Photo: Ashley Major/Huntington Ingalls Industries.

He said the study includes the “appropriate stakeholder members” to learn everything maintainers learned from the SSGNs and roll the lessons into the SSBNs.

The SSGNs are set to retire in the mid- to late- 2020s. Each SSGN has 24 vertical launch tubes that can carry a total of 154 Tomahawk missiles per submarine. The Virginia Payload Module (VPM) in new Virginia-class attack submarines (SSNs) are planned to replace the SSGN Tomahawk capability.

Tammen underscored the upcoming ramp up in production when the industrial base starts building both Virginia and Columbia-class submarines.

While the Navy is currently delivering two Virginia boats per year, “if you look at the workload when we start delivering Virginia Payload Module and Columbia it’s like five Virginias per year,” Tammen said.

The first Block 5 Virginia Payload Module-equipped Virginia-class submarines will start production in 2019. Tammen said Blocks 6 and 7 will then start featuring “very interesting things.”

He said his office is looking beyond fitting only Tomahawk missiles into the VPM; they may also host unmanned undersea vehicles (UUVs) and other undersea and seabed weapons to increase the vessel’s tactical warfare capabilities.

Eventually, Block 7 submarines will reach its limit in increasing speed, acoustics, and other capabilities, whereupon the Navy will then transition to a new SSN, Tammen said.

The Navy is still determining major aspects of the next SSN like payload, hull size, and engine type, but Tammen said it will “put fast back into fast attack. Fast with stealth.”

Huntington Ingalls Industries’ [HII] Newport News Shipbuilding and General Dynamics [GD] build the Virginia-class submarines while General Dynamics Electric Boat is the prime contractor for the Columbia class.