Virginia Payload Module to Give Subs More Firepower

General Dynamics Electric Boat image

The Navy is augmenting its attack submarine fleet by increasing its capacity to deploy weapons and other key payloads in a potential conflict.

In December, senior Navy leaders, elected officials and industry representatives gathered at General Dynamics Electric Boat’s Quonset Point Facility in North Kingstown, Rhode Island, for the keel-laying ceremony for the USS Arizona, the 30th of the service’s Virginia-class fast attack submarines.

Once completed, the Arizona will be the first in its class to be equipped with the Virginia Payload Module, a new hull section that will enable the Arizona and subsequent Virginia-class ships to deliver a variety of capabilities such as weapons, vehicles and undersea payloads, according to the Navy.

“The boats in this class are the most advanced attack submarines ever designed. Their stealth, firepower and maneuverability are superior to every other attack submarine force in the world,” Rear Adm. Jonathan Rucker, the Navy’s program executive officer for attack submarines, said in a press release. “Building, operating and maintaining Arizona and other Virginia-class subs is crucial to ensuring the Navy’s ability to project power in an ever-shifting global threat environment, and to maintaining peace and the free operation of our sea lanes.”

The first ship in the class, the USS Virginia, was commissioned in 2004. The first 10 Virginia-class subs — Block 1 and Block 2 of the class — feature 12 Vertical Launch System tubes for firing Tomahawk cruise missiles, a Navy fact file on attack submarines said.

Beginning with Block 3, the Navy redesigned “approximately 20 percent of the ship” to reduce acquisition costs, the fact file said. The redesign included replacing the 12 vertical launch tubes with “two large diameter 87-inch Virginia Payload Tubes, each capable of launching six Tomahawk cruise missiles using Multiple All-up Round Canisters,” the file said. The added volume of the tubes provides more payload flexibility while simplifying construction and reducing acquisition costs, the file stated.

The Navy maintained this design on the Block 4 ships, but starting with the Arizona — the second sub in Block 5 — the Navy introduced the Virginia Payload Module, or VPM, featuring four additional large diameter payload tubes, the fact file said.

“Due to their location, each VPM payload tube is capable of carrying seven Tomahawk cruise missiles adding 28 missiles per” module, the Navy file said. It also “reconstitutes the ability” of the Virginia class to hold dry deck shelters that can launch and recover special operations forces, “and allows the Navy to host additional advanced payloads via multiple ocean interfaces,” the file added.

The module is 84 feet long — bringing the total length of the Virginia-class subs up from 377 feet to 461 feet, the Navy file said — and can store and launch “payloads with diameters larger than the 21-inch diameter of a torpedo or Tomahawk missile,” a December Congressional Research Service report on Virginia-class sub procurement said. Block 6 of the Virginia class is expected to include the VPM as well, a Navy spokesperson said in an email.

General Dynamics Electric Boat — the prime contractor for the Virginia class — awarded contracts in 2016 to BAE Systems and BWX Technologies for the production of the launch tubes, with BAE Systems winning additional production contracts in 2018 and 2019, per company press releases.

The additional firepower provided by the module “is intended to compensate for a sharp loss in submarine force weapon-carrying capacity that will occur with the retirement in FY2026-FY2028 of the Navy’s four Ohio-class” guided missile submarines, or SSGNs, the Congressional Research Service report said. The Ohio class also includes 14 ballistic missile submarines, or SSBNs, which the Navy will replace with its Columbia-class boats.

Each of the Ohio-class SSGNs — which are 560 feet long, according to a Navy fact file — can carry 154 Tomahawk missiles, “so you’d end up with about four Virginia class Block 5’s being equivalent to one [Ohio class],” said Bryan Clark, a senior fellow and director of the Center for Defense Concepts and Technology at the Hudson Institute.

“The idea was … build 10 Block 5 and then 10 Block 6 Virginia class so that will give us 20 submarines with 40 additional missile tubes, and that will compensate for that loss of missile capacity,” he added.

However, due to construction delays on Block 4 and Block 5 Virginia-class subs, there will be a gap between the retirement of the Ohio-class SSGNs and the commissioning of the Virginia-class subs that have the module, Clark said.

Media reports in the spring of 2019 indicated that the two contractors in charge of Virginia-class submarine construction — General Dynamics Electric Boat and Huntington Ingalls Industries — “were experiencing challenges in meeting scheduled delivery times as the Virginia-class program was transitioning from production of two ‘regular’ Virginia-class boats per year to two VPM-equipped boats per year,” the Congressional Research Service report detailed. On the company’s quarterly earnings call in February 2022, Huntington Ingalls Industries’ then-COO and current president and CEO Chris Kastner confirmed the company had missed submarine milestones for two Block 4 Virginia-class subs at the end of 2021.

Due to these delays, the Navy will be left “without … an equivalent undersea missile capacity” to the Ohio-class subs for a time, Clark said. A Department of the Navy Special Acquisition Report from December 2021 projected a November 2028 delivery date for the USS Arizona.

“There’s a learning curve, but they will get more efficient at building them after they’ve built a few,” he said. “Both shipbuilders have built a lot of additional infrastructure to support construction of Columbia and the Block 5 Virginia class, [and] that infrastructure is now being brought into the production process.”

Compared to previous Virginia-class subs, those featuring the VPM will require larger crews “in the weapons department to be able to manage the missile tubes,” Clark said. The increase in size and weight due to the module will likely lead to maneuverability concerns as well, he added.

The Navy “has performed extensive analysis of the impact of” the VPM on the Virginia-class subs, the Navy spokesperson said. “The expanded volume allowed for additional margin” for systems such as hydraulics and cooling, “with modest impacts to maneuvering and speed,” the spokesperson said.

“In terms of ship handling, the Navy expects that this will be, more or less, not a big difference from the Virginia class as it currently exists,” Clark said. “But I think everybody who’s a submariner anticipates that the ship will handle a lot differently. It’ll be heavier, it will probably be slower … so there is a concern that potentially these Block 5 and then Block 6 submarines may have more limited operations envelopes, if you will, compared to the previous blocks of Virginia.”

The Virginia-class subs with the Virginia Payload Module will likely be used more for patrolling or special operations support missions — similar to the Ohio-class SSGNs — as opposed to “traditional submarine missions” such as gathering intelligence in contested waters, Clark said.

The module could prove particularly useful for supporting special operations forces, he added.

“The Virginia class has lock-in, lock-out chambers, and it’s got the ability to carry the dry deck shelter that the swimmer delivery vehicle lives in,” Clark said. “The Block 5’s will have the ability to carry additional vehicles.”

Instead of missiles, special operators could store vehicles or gear in the tubes and retrieve this “specialized equipment” when the mission begins, he said.

The VPM can also deliver unmanned underwater vehicles, a Navy press release said. While the service does have and use these vehicles primarily for mine hunting — and could use them in the future for “undersea warfare” missions — deploying them from the new modules could prove a challenge, Clark said.

“The tubes open on the top of the submarine, so if you have undersea vehicles you want to deploy … they’re going to have to swim out the top, which is not preferred,” he said. “You prefer them to be able to swim out horizontally.”

As of now, “there are no planned unmanned vehicles being launched from the Virginia Payload Module itself, however submarines are planned to incorporate a torpedo tube launched variant of the Razorback Unmanned Underwater Vehicle as well as Submarine Launched Unmanned Aerial System,” the Navy spokesperson said.

The Navy is more likely to “use these tubes to carry a variety of missiles,” Clark said, “because you can deploy unmanned vehicles from lots of other places, whereas you can only deploy weapons from certain missile cells and containers.”

Along with Tomahawk missiles, the Navy is interested in deploying hypersonic weapons — systems that can reach Mach 5 or higher, or at least five times the speed of sound — from the module once these capabilities are developed, he said.

Hypersonic weapons have become a top priority for the Defense Department. The Navy is currently working on a hypersonic weapon program called Conventional Prompt Strike, while the Army is developing the Long Range Hypersonic Weapon.

The two services conducted a test of their hypersonic capabilities in October. Both programs “are on track to support the first fielding of a hypersonic capability to the Army in [fiscal year] 2023,” a Navy press release said.

Hypersonic weapons are certainly “something that the Navy and Congress and DoD want to try to integrate onto the Virginia class, because I think they see that as the best platform to have a mobile way to deploy that weapon in theater” without having to be “dependent upon host nation support,” Clark said.

While the Navy brought up the potential of using the VPM to carry unique systems such as unmanned underwater vehicles, the service is likely to prioritize carrying Tomahawk missiles, hypersonics and special operations equipment in the module, Clark said.

“I think what they’re finding in practice is that it costs a lot of money to put something into a payload module like that, and then we have to probably make some choices,” he said.

“Certain payloads end up being most advantageous, and other payloads are nice to have or interesting, but maybe are more experimental and not likely to be the production equipment that we actually put on the ship.”

Topics: Shipbuilding