As the U.S. Navy embarks on an ambitious effort to grow the size and capability of its fleet, the Virginia-class attack submarines (SSNs) continue to be a critical element in the fleet of today and into the future.

 

Growing Threat

Submarines are a worldwide concern to the U.S. Navy and its allies and partners. According to the website World Atlas, navies around the globe have more than 500 submarines altogether, spread among 38 countries. China, North Korea, Russia, and Iran have about 40 percent of those submarines. According to the South China Morning Post, published in Hong Kong, “Asian Pacific countries are engaged in a submarine arms race, with an estimated 228 full-sized submarines operating in the East and South China Seas — a number that is expected to rise to 300 within a decade.”

The 2018 National Defense Strategy emphasizes building a more lethal force, particularly to counter Chinese and Russian threats, so submarines are and will remain in high demand.

 

 

SSNs are an extremely effective weapon against other submarines; with their intelligence, tracking, and targeting capability they are critical assets in the battle force. And the need for a capable attack submarine fleet to counter increasing numbers of potential adversaries operating submarines is growing.

At a Department of Defense press briefing on the president’s fiscal year 2020 defense budget for the Navy last March, Deputy Assistant Secretary of the Navy for Budget Rear Adm. Randy Crites talked about the importance of procuring highly capable platforms such as the Virginia-class SSNs in this era of great power competition.

 

 

“We know that both Russia and China are fielding high-end military capabilities, and frankly, ideologies that are incompatible with the rules-based international order,” Crites said. “The competition is clearly on.”

Commander of U.S. Indo-Pacific Command, Adm. Phil Davidson, would agree. “My day-to-day requirement is met by slightly over 50 percent of what I’ve asked for,” Davidson said in reference to his requests for submarines to be assigned to his part of the world.

Only a few years ago, the Navy was growing its fleet to 308 ships. Today there are 295 deployable battle force ships. The December 2016 Force Structure Assessment (FSA) called for 355 ships, and that includes more attack submarines – 18 of them above the current plan.

 

 

According to a February 2020 report from the Congressional Research Service, the Navy’s force-level goal for SSNs is to achieve and maintain a force of 66 boats. The Navy’s SSN force included 50 boats at the end of FY2019, including Los Angeles (SSN 688) class boats; Seawolf (SSN 21) class boats; and Virginia (SSN 774) class boats.

While more submarines would be welcomed by the combatant commanders and industry alike, the Navy will be challenged by funding, the industrial capacity to increase construction, and the ability to recruit and train more qualified officers and sailors.

The Virginia class traces its origins to the 1991 “Centurion” study, which sought to develop a less-expensive alternative to the Cold War-era Seawolf class, of which just three were built. The Centurion became known as the New Attack Submarine, and then the Virginia class. Many new techniques were used to design and build the Virginias, including computer-aided design (CAD) and the use of commercial off the shelf components instead of more costly “MILSPEC” equipment. Computer processing capability was evolving at a rapid pace because of a thriving civilian market hungry to get the latest and best personal computer or laptop. Instead of developing Navy-unique technology for what would be a very small market, the Navy decided to take advantage of constantly improving commercial technology.

 

 

The Virginia-class submarines can be categorized in blocks. The first four ships (SSNs 774 – 777) are Block I. The second, Block II, group of six submarines (SSNs 778 – 783) incorporated improved modular construction techniques to reduce the time required to build them. These first ten boats proved out the class design and construction techniques. The eight Block III boats (SSNs 784 – 791) have a redesigned bow for a new sonar array and the Virginia Payload Tubes (VPTs), which replace the 12 single-purpose vertical launch system (VLS) missile tubes in the bow section; the two large-diameter VPTs are each capable of launching six Tomahawk missiles utilizing the same Multiple All-Up-Round Canisters (MACs) currently used on the Navy’s four guided-missile submarines (SSGNs). Beginning with SSN 792, the following 10 Block IV submarines include the changes of Block III and take advantage of a Navy and industry effort to reduce operations and sustainment costs called Reduced Total Ownership Cost (RTOC). Beginning with the second Block V submarine, an extended hull adds the Virginia Payload Module (VPM) with four additional payload sized tubes that will dramatically increase the number of weapons carried.

 

The commander and executive officer of USS Colorado (SSN 768) stand in the boat’s sail next to the submarine’s sensor masts. Virginia-class submarines have AN/BVS-1 fiber-optic photonics masts located outside the pressure hull instead of the traditional periscope. Each of the two masts contains high-resolution cameras, light-intensification systems, infrared laser rangefinders, and an integrated electronic support measures (ESM) array.

 

Power for these submarines comes from a S9G pressurized water reactor (PWR) style nuclear reactor, which provides 40,000 shaft horsepower to drive the boat at speeds up to and greater than 25 knots.

 

Growing Collaboration

Only two U.S. shipyards build nuclear-powered submarines for the U.S. Navy.

Virginia-class boats are built jointly by General Dynamics Electric Boat Division (GD/EB) of Groton, Connecticut, and Quonset Point, Rhode Island, and Huntington Ingalls Industries’ Newport News Shipbuilding (HII/NNS), of Newport News, Virginia. Both shipyards have been building submarines for decades. The arrangement keeps both shipyards viable and preserves their submarine design and construction skills and expertise. Each boat is made up or parts from each shipyard, such as hull sections and the reactor compartments, and the builders alternate the final assembly of the boats.

 

 

While the Virginia class began in the 1990s, it will be closely tied with the newest submarine program, the Columbia class of ballistic missile submarines, which will replace the current Ohio class of strategic deterrent submarines. While the Columbia and Virginia classes span different generations and have different missions, the Navy’s Submarine Unified Build Strategy (SUBS) acknowledges the benefits of finding commonality in both submarine programs to ensure executability and enable affordability during the planned ramp-up in submarine production at the two shipyards and the respective supplier base.

The first four Ohio-class ballistic missile submarines (SSBNs) were converted to nuclear-powered cruise missile submarines (SSGNs) to carry up to 154 conventional cruise missiles, primarily Tomahawk land-attack missiles (TLAMs). This greatly improved the Navy’s striking capability. But these ships will begin decommissioning in the late 2020s, leaving a gap in TLAM capability. The 28 additional missiles carried in each of the VPM-configured ships help address that shortfall.

 

 

The first Virginia-class SSN was commissioned in 2004. The first Columbia-class SSBN isn’t expected to join the fleet until 2030, and commence its first strategic deterrent patrol in 2031. Much of the Columbia program will leverage technology developed for the continually evolving attack submarine program.

Meanwhile, the Navy and its industry partners have been steadily working on building the Virginia class more efficiently and effectively.

 

Growing Capability

Ramping up from 308 ships to a fleet of 355 requires the Navy to leverage existing designs instead of taking the time and expense to design new ship classes. In the case of the Virginia class, there has been a steady improvement in capability while cost and schedule have improved.

Having the latest and greatest model usually means that it will be more expensive, too. However, the successive iterations of the Virginia class are being built faster, with higher quality, and actually cost less over the total life of the ship.

 

 

The evolution of the Virginia class has also resulted in progressively more capable submarines. The submarines through the Block IV boats have the same dimensions. Replacing the 12 single-purpose small diameter VLS missile tubes in the bow section with the simpler two large-diameter VPTs, allows for larger future payloads such as unmanned vehicles. As with all U.S. Navy submarines, the Virginia class are also armed with Mk. 48 Advanced Capability (ADCAP) torpedoes. The Block V boats’ 84-foot-long VPM will add four additional payload sized tubes into the body of the ship. The VPM tubes will be located inside the pressure hull, making them accessible for inspection, maintenance, or alterations.

TLAM capacity is the primary driver right now for VPM, however the Navy is also looking at other weapons to be carried on the SSNs, such as longer-range anti-ship weapons or an extended-range torpedo.

 

 

The RTOC approach taken starting with the Block IV submarines offers multiple benefits over the life of the ship.

Not only has Virginia class construction time been reduced, but less time is required to find problems during the “shakedown period” and to fix them during the “post shakedown availability” or PSA. That means the latest combat system can be installed during construction, making these boats ready for mission-tasking immediately at delivery.

 

Growing the Fleet

The Navy is getting capability to the fleet faster while saving money by employing multi-year block-buy contracts. In 2014, the Navy ordered the 10 Block IV boats in a $17.6 billion “block buy,” up to then the largest shipbuilding contract in U.S. Navy history in terms of total dollar value. More recently, the Navy awarded an even larger nine ship $22.2 billion contract in December 2019 for nine Virginia-class attack submarines (with an option for a tenth), eight of which will have a VPM.

“The Block V contract balances the right mix of undersea quantity and capability with a profile that continues to stabilize the industrial base. This balance and stability will enable the success of submarine acquisitions across the enterprise,” said Virginia Class Program Manager Capt. Christopher Hanson. “Our warfighters, the Navy, and the nation will benefit greatly from the new capabilities that the Block V submarines will bring to the fleet.”

 

 

Construction continues to go well in the Virginia program, with ships being delivered within the contracted budget. Construction of the prototype VPM tubes has begun, and construction of the first Block V boat began in FY 19.

“Block V Virginias and Virginia Payload Module are a generational leap in submarine capability for the Navy,” said Program Executive Officer for Submarines Rear Adm. David Goggins. “These design changes will enable the fleet to maintain our nation’s undersea dominance.”

 

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