The United States Navy’s Virginia-class attack submarine program. Using expertise developed from building 53 attack submarines (SSNs) over four decades, Northrop Grumman’s Shipbuilding sector is constructing the nation’s newest SSN – the Virginia class, the most advanced submarine in the world. Northrop Grumman is producing the Virginia-class submarines in a teaming arrangement with General Dynamics Electric Boat as part of a U.S. Navy effort to preserve sub-making skills at both shipyards. The team is currently under contract to build the first 10 ships of the Virginia class, which is ultimately expected to total 30 vessels.
Mission requirements in a new security environment
The Navy’s SSNs perform a variety of missions, unlike the ballistic missile subs that carry nuclear warheads and generally remain hidden at sea to deter a nuclear strike on the nation. During the Cold War, a fleet of 100 SSNs operating throughout the world’s oceans tracked Soviet ballistic missile subs, gathered valuable intelligence, and remained on the ready to engage enemy nation ships in case of conflict.
Today, while the Navy must still be equipped to contend with a future major maritime adversary, its more immediate challenge is the unconventional threats of global terrorism, regional conflict and WMD proliferation. Operations dealing with such threats in shallow foreign littoral waters are likely to become increasingly important.
Thus, U.S. submariners are devoting increased or new attention to littoral missions like persistent and covert Intelligence, Surveillance and Reconnaissance (ISR), anti-submarine warfare, mine detection/clearance, submerged land attack and injection/recovery of U.S. Special Operations Forces.
In littoral operations, our maritime forces may confront rogue states or other adversaries who practice Anti-Access/Area Denial (A2/AD). The concept of A2/AD is that if the U.S. Navy can be kept out of the littoral in question, at least for some operationally meaningful period, then both the ground and tactical aircraft forces necessary for sustained operations there can also be kept out, if for no other reason than that logistics support for them becomes too difficult without maritime transport.
A2/AD measures involve undersea operations in which our forces must contend with advanced Anti-Ship Cruise Missiles (ASCMs) fired by high-performance diesel-electric submarines, as well as with a mix of both sophisticated and vintage sea mines. Other components of a fully developed A2/AD system involve land-based ASCMs, Theater Ballistic Missiles fired from mobile Transporters/Erectors/Launchers that threaten likely supporting seaports and airbases, and integrated/relocatable air defenses to protect these assets.
The key to “taking down” this A2/AD complex is a platform insensitive to access-denial that has the mobility to get to (and into) the littoral of interest quickly, the endurance to maintain a persistent presence there, the stealth to do so undetected, and the sensors and firepower to locate, classify, report on and engage a broad range of threats and obstructions. All these characteristics are found in the U.S. nuclear-powered attack submarine.
Capabilities needed: Virginia-class SSN
Because the Los Angeles-class submarines that make up most of the current U.S. SSN fleet are reaching the end of their useful lives, the U.S. Navy is building the new Virginia class of SSNs that is designed to excel in littoral environment missions in addition to traditional open ocean operations. These revolutionary ships are the first to be delivered that are designed expressly for the unconventional 21st century warfighting environment.
The new submarine is 377 feet in length with a beam of 34 feet. It can operate at underwater speeds of more than 25 knots, dive more than 800 feet and stay submerged for up to three months at a time. The submarine, powered by a nuclear reactor that will not need refueling, has an estimated life span of at least 33 years.
Virginia-class submarines are notable for their stealth -- they are as quiet acoustically as Seawolf-class SSNs and harder to detect electromagnetically than all predecessor SSNs -- and have better maneuverability in shallow waters.
The Virginias feature a new command-and-control systems module that integrates the vessel’s sensors, countermeasures, navigation and other functions.
The ships are also designed for the network-centric operations embraced as a top priority by all the services. A pair of mast-mounted satellite communications antennae will allow simultaneous satcom links in the Super High Frequency and Extremely High Frequency ranges. The submarine need not surface to communicate, however. Various antennas are sensitive enough to work from a shallow depth, while expendable, buoy-mounted sensors tethered by fiber-optic links will allow the vessel to carry out two-way encrypted communications with its base via satellite or aircraft.
In addition, the new submarines are equipped with arrays of diverse sensors that allow them to collect more intelligence, better intercept communications and track ship movements more precisely.
When surveying surface objects from a submerged state, the Virginia’s crew relies on a pair of non-hull penetrating “photonic masts” instead of the traditional periscopes. According to Becky Stewart, vice president of the Virginia SSN program at Northrop Grumman Shipbuilding, “Photonic masts use high-resolution cameras housed in the submarine’s dorsal fin-like ‘sail’ to capture images digitally. Sailors in the sub’s command station and all around the ship can view color, high-resolution black and white or infrared images on flat-panel displays, and then share those images with other ships in the theater or with command centers ashore.” Masts are controlled with joysticks that enable operators to quickly obtain a 360-degree view.
The photonic mast provides many benefits that periscopes are unable to offer. For example, an operator can shoot a laser range finder through the photonic mast to obtain the range of a contact – which is then automatically entered into the sub’s weapons system.
In conducting ISR beneath the surface, Virginia-class ships will process, use and distribute data gathered by highly sophisticated sensors mounted all over the ship, as well as by arrays of sensors on cables towed behind the ship.
Says Stewart, “These sensors can detect objects as large as quiet, diesel-powered submarines and as small as underwater mines.”
An acoustic countermeasures suite provides the submarine with torpedo attack warnings.
In combating adversaries, the Virginia-class submarine will rely on Raytheon’s AN/BYG-1 Combat Control System along with a variety of weapons: advanced heavyweight torpedoes, mines, Unmanned Undersea Vehicles (UUVs) for horizontal launch, and Tomahawk cruise missiles that have a range of 900 nautical miles when fired from vertical launch tubes.
In both the littorals and open ocean, the submarines will be able to use torpedoes for engaging large surface ships or conducting anti-submarine warfare. In the littorals, superior non-acoustic stealth and the sonar sensors will make the Virginias better able than their predecessors to identify and penetrate mine fields and to deploy mines or UUVs offensively. If targets are land-based, the stealthy ships will also be better able to launch surprise strike missions from close in and, if necessary, to fire Tomahawk cruise missiles far inland.
Perhaps the most novel of the new capabilities of Virginia-class submarines is their ability to transport Special Operations Forces deeper into enemy territory than ever before. The submarines are equipped with an integral lock-out/lock-in chamber able to host individual divers or support a mini-submarine, such as the Advanced SEAL Delivery System. This chamber is large enough for nine crew members and equipment, more than tripling the capacity of older submarines.
Besides supporting particular missions, the new class of submarines offers general operational and maintenance advantages. For instance, technological innovations enable the Virginia to operate with smaller crews – fewer than 120 people, compared with more than 130 for the Los Angeles and Seawolf attack classes. Further, because of the Virginias’ emphasis on open systems and modularity, these ships will be able to seamlessly incorporate future innovations in sensors and other capabilities as soon as they are developed.
Sustaining the Virginia-class program into the future
To facilitate realization of its plan to build a total of 30 Virginia-class submarines, the Navy is working with the shipbuilding industry on ways to reduce costs A key element of this initiative is increasing the production of Virginias to two ships per year. However, the planned increase depends on the Navy’s being able to acquire the new submarines for the reduced cost of $2 billion per ship (in FY-05 dollars).
The Northrop Grumman-General Dynamics team is now very close to achieving this cost goal as a result both of adopting more efficient production techniques and making several design changes to the ship.
As for production changes, Northrop Grumman, for example, has upgraded outfitting facilities to provide a covered production area in which ships can remain until they are ready to be launched and is also building ships in larger modular sections to facilitate a simplification of final assembly that saves much time.
Design changes include replacing the traditional sonar sphere with a new hydrophone array fitted inside the bow dome – and also changing the configuration for the Tomahawk cruise missile launchers mounted behind the sphere. Both changes will first appear in SSN 784, the 11th ship, construction of which will begin in 2009.
In addition, Northrop Grumman is developing technologies – such as external torpedo launchers and electric ship systems – that could pave the way for future Virginia-class upgrades, as well as the potential backfit of these upgrades to Los Angeles-class and Seawolf-class submarines.
As Stewart explains, “In today’s asymmetric warfighting environment, the Navy will rely heavily on Virginia-class ships both for blue water and littoral operations. Northrop Grumman is committed to supporting this requirement with performance-improvement and cost-reduction approaches that deliver the best submarines in the world.”
Photo credits: the U.S. Navy, General Dynamics Electric Boat and Northrop Grumman Shipbuilding.
Today, while the Navy must still be equipped to contend with a future major maritime adversary, its more immediate challenge is the unconventional threats of global terrorism, regional conflict and WMD proliferation. Operations dealing with such threats in shallow foreign littoral waters are likely to become increasingly important.
Because the Los Angeles-class submarines that make up most of the current U.S. SSN fleet are reaching the end of their useful lives, the U.S. Navy is building the new Virginia class of SSNs that is designed to excel in littoral environment missions in addition to traditional open ocean operations. These revolutionary ships are the first to be delivered that are designed expressly for the unconventional 21st century warfighting environment.
When surveying surface objects from a submerged state, the Virginia’s crew relies on a pair of non-hull penetrating “photonic masts” instead of the traditional periscopes. According to Becky Stewart, vice president of the Virginia SSN program at Northrop Grumman Shipbuilding, “Photonic masts use high-resolution cameras housed in the submarine’s dorsal fin-like ‘sail’ to capture images digitally. Sailors in the sub’s command station and all around the ship can view color, high-resolution black and white or infrared images on flat-panel displays, and then share those images with other ships in the theater or with command centers ashore.” Masts are controlled with joysticks that enable operators to quickly obtain a 360-degree view.
In both the littorals and open ocean, the submarines will be able to use torpedoes for engaging large surface ships or conducting anti-submarine warfare. In the littorals, superior non-acoustic stealth and the sonar sensors will make the Virginias better able than their predecessors to identify and penetrate mine fields and to deploy mines or UUVs offensively. If targets are land-based, the stealthy ships will also be better able to launch surprise strike missions from close in and, if necessary, to fire Tomahawk cruise missiles far inland.
To facilitate realization of its plan to build a total of 30 Virginia-class submarines, the Navy is working with the shipbuilding industry on ways to reduce costs A key element of this initiative is increasing the production of Virginias to two ships per year. However, the planned increase depends on the Navy’s being able to acquire the new submarines for the reduced cost of $2 billion per ship (in FY-05 dollars). 