The Virginia Attack Boat Brings New Potency to the Fleet

Later Versions May Be Fitted With Advanced Sail and Powerful New Reactor

By JOHN S. HEFFRON

From its inception, the Virginia-class has been an innovative platform for both its warfighting capabilities and for its unique and effective design, development, construction, and testing processes. With this 30-ship submarine class, the Navy has established a new baseline for submarine design and development. Virginia (SSN 774), the namesake of a new class of submarines optimized for both deep water and littoral, or shallow water, operations, is scheduled to be delivered on time to the Navy in June 2004--a major achievement for submarine construction.

Virginia-class Warfighting Capabilities

After the fall of the Soviet Union, the U.S. Navy re-examined its mission. It became evident that in addition to maintaining superiority in deep-water operations, submarines would need to become more oriented toward littoral warfare to meet the challenges of the 21st century. Therefore, the Virginia class was designed for battlespace dominance in both the coastal waters and the open ocean. Virginia's broad mix of capabilities will allow her to conduct very diverse missions, enabling the newest class of fast attack submarines to fulfill the Chief of Naval Operations' vision of the 21st century Navy--Sea Power 21. This concept includes offensive capabilities--"Sea Strike;" defensive capabilities--"Sea Shield;" and the idea of projecting U.S. sovereignty on the high seas--"Sea Basing." During Operation Iraqi Freedom, attack submarines made major contributions to Sea Basing by their presence in the Gulf, their ability to covertly stay on-station for months, and by their ability to host and support special operations forces (SOFs). Fast attack submarines also took part in Sea Strike operations by launching almost one-third of the Tomahawk missiles used in that conflict, and demonstrated Sea Shield by undertaking anti-submarine (ASW) measures and sanitizing vast stretches of oceans to help protect surface forces. While the current submarine force is capable of carrying out these Sea Power 21 initiatives, the Virginia class will do so with more robust capabilities and with a high degree of mission flexibility.

Mission flexibility

Virginia is the first U.S. nuclear-powered submarine tailored to conduct warfare in both the deep water and littoral regions, with missions ranging from antisubmarine warfare to land attack to covert intelligence gathering, and SOF support. Virginia-class submarines will support these forces with significantly upgraded communications and revolutionary advancements in the collection and dissemination of information from various deployed assets. In fact, these information dissemination capabilities will be a key enabler of ForceNet, which ties together the three pillars of Sea Power 21.

Whereas the Virginia class will have capabilities and roles similar to the current Los Angeles class, Virginia will take undersea warfare to the next level and ensure the Navy's unquestionable undersea battlespace dominance. It will have more internal weapons that, when coupled with its improved sonar and torpedoes, will make Virginia a highly effective ASW asset. Strike operations will be carried out via improved planning centers and the ship will be able to launch Tomahawk cruise missiles from 12 vertical launch tubes and its four torpedo tubes.

The Virginia class provides a high level of support for SOF mission planning and execution. The class design includes many features to support SEAL forces. These features include a nine-person "lock-out trunk" to support SEAL team deployment; either a dorsal-mounted Advanced Seal Delivery System (ASDS) mini-sub or a Dry Deck Shelter; and a Torpedo Room designed to be fully reconfigurable, to accommodate SEAL teams, their equipment, and the ship's on-board weapons.

Improved Capabilities

The Virginia class will include technologies that will enhance its warfighting effectiveness. One example is its sonar suite. Virginia's "ears" include a spherical array in the ship's bow that is used for active and passive ranging. It will also have a hull-mounted lightweight wide aperture array, a towed array for passive ranging, and small-object avoidance/mine-avoidance sonars built into the "chin" and sail of the ship for littoral operations.

Virginia also has a number of command-and-control system module enhancements. For example, Virginia is the first attack submarine to be built without optical periscopes. Instead, two photonics masts provide three types of electronic images (color, infrared, and black and white) that are displayed on flat-panel consoles. Unlike traditional periscopes, the photonics masts do not penetrate the hull when lowered, eliminating the need to link the location of the control room, sail, and periscopes. Consequently, Virginia's command-and-control system module (CCSM) has been moved down one deck and enlarged. With periscopes no longer dominating the larger control room, the module has been laid out with utility and connectivity in mind. The commanding officer (CO) has a better opportunity to assimilate data from a variety of systems and make better decisions because combat control, ship control, sonar, photonics, radio, and SOF control are all located around a central command station that is linked to each system. The CO will have an unprecedented ability to retrieve and assimilate information as needed.

Much of this information will be made available through the ship's classified local area network (LAN) that is tied to key command-and-control system module elements. Additionally, a separate wireless LAN exists for noncombat and personal uses by the crew. The combined information network enhancements plus the enhanced computer capability will allow the ship to operate with reduced paper or hard copy stowage.

Even the ship control system has revolutionary advancements compared to those of previous submarine classes. Virginia's ship control system takes advantage of "fly-by-wire" digital technology, with several layers of redundancy, to control steering and diving. This digital system sends electronic commands rather than using a hydraulic mechanical-based system. In fact, a joystick and computer touch screens will be the ship's primary steering controls.

A New Design Approach

Virginia's initial design effort began in the early 1990s. Computer-aided design (CAD) and computer-aided manufacturing (CAM) programs at that time had matured to the point where design features could be analyzed through computerized visualization, which reduced the need for wooden mockups typically used to verify submarine design. Digital design not only reduced mockup construction costs, it eliminated many potential problems from the routing of piping and cabling and other areas that are not easily detected when using models. In fact, most issues were resolved quickly and without extensive deliberations. Furthermore, the digital design resides in a single database which supports design, construction, material, and logistic requirements.

CAD/CAM has been so successful that the number of changes identified during the construction of Virginia is literally an order of magnitude less than those identified during construction of the previous submarine class, Seawolf. This confirms the excellence of this design approach, and has set a new benchmark for future efforts.

New Manufacturing Processes

The CAD/CAM design directly supports digital manufacturing technology, allowing the design data to be used at both the General Dynamics/Electric Boat and the Northrop Grumman Newport News Operations shipyards with only minor interpretation needed to address differences in individual machinery. This enables the Navy and the shipbuilder teams to use the most efficient manufacturing techniques available.

In a radical departure from previous practices, the construction of each ship involves sectional work by the two shipbuilders with alternating responsibility for final ship assembly and testing. This maintains submarine construction and testing expertise at two shipyards. For construction of this class, Electric Boat is the prime contractor and Northrop Grumman Newport News Operations is a principal subcontractor. Electric Boat provides pressure hull cylinders used for all ships from its Quonset Point, R.I., facility, while Newport News provides the pressure hull ends and the bow and stern sections for all ships. Each contractor also manufactures and tests certain assemblies for each ship. Electric Boat produces the engine rooms and the command-and-control system modules, while Newport News produces the auxiliary machinery and torpedo rooms. A module is built, tested, and then inserted into its proper hull section. The assembling shipyard then welds cylinders together, conducts testing, and delivers the ship. Although the delivery yard accomplishes roughly two-thirds of the work, ship delivery alternates between yards, ensuring workload parity. Currently, four ships of the class are under construction. The lead ship will be christened in August 2003 with delivery expected to be on time in June 2004.

Change to "COTS"

When the design for Virginia began, the Department of Defense was beginning to shift its emphasis toward the use of commercial-off-the-shelf hardware. This resulted in lower procurement and logistics costs for shipboard electronics and facilitated system upgrades. An "open-system architecture" was also chosen as a means of easing integration and system upgrades.

All these and several other elements of the combat system are integrated into a package that comprises the command-and-control system module, which is fully tested ashore and end-loaded into the hull as a unit.

Shore-Based Testing, Training on CCSM

The many complex systems contained in the command-and- control system module require a test program that is carefully conceived and executed to remove the module from the critical path, thereby reducing risk for ship construction.

In the fall of 2000, electronics equipment was delivered to the command-and-control system module off-hull assembly and test site (COATS) at Electric Boat in Groton, Conn. Testing at COATS--which involved more than 70 Navy uniformed personnel--took place throughout 2001, finishing in May 2002. It was highly successful, completing 40 percent of the ship's total command-and-control system testing, including an operational evaluation by the Operational Test and Evaluation Force (OPTEVFOR)--an independent testing group that reports directly to the Chief of Naval Operations. OPTEVFOR evaluated the ship system as potentially operationally effective and potentially operationally suitable, the highest possible rating for a system not yet delivered to the fleet. Since that time, developers have been working to correct any noted deficiencies in these systems in preparation for the shipboard testing that began in June 2003.

Virginia's final forward-end electronics system installation was accelerated from July to May 2003 and the beginning of shipboard testing was accelerated from September to June. This increased the test time available before the February 2004 sea trials by 60 percent. Shipboard testing is a large task, involving more than 11 million lines of source code, 23 interconnected systems, and 23 input/display consoles.

COATS is also being used to provide crew training while the ship is being constructed. This shore-based training will help ensure that the crew is prepared to take the ship to sea at the earliest possible time. Virginia's crew received some training during the testing of its command-and-control system module at COATS, and is also receiving additional training using the module for the second ship of the class, Texas, during its testing at COATS. The systems supplied for the Texas are improved by the corrections resulting from Virginia's testing, and will therefore achieve greater success in testing both ashore and afloat.

All of these innovations in design, development, construction and testing are invaluable during the submarine's 30-year life. Because of the modularity built into the Virginia class, these innovations will allow submarines to be individually adapted to specific threats and warfighting needs on a real time basis.

The Future of the Virginia Class

The Navy is also developing new technologies that take advantage of the vast undersea battlespace available to submarines. These include additional weapon payloads, deployable sensors that will position themselves in the water, transit onto land, or fly through the air and transmit information back to the submarine, and autonomous unmanned underwater vehicles (UUVs) for remote missions such as mine hunting and reconnaissance. These technologies may be placed aboard future Virginia-class submarines, making them even more potent, flexible warfighters. These new technologies will demand much greater energy over the life of the ship. Whereas the Virginia-class submarines under construction today have a newly-designed reactor plant that meets their increased energy needs, a new reactor, the Transformational Technology Core, is being developed that will satisfy the even larger energy demands of future submarines.

The research and development of an advanced sail is in the works. The advanced sail will allow for a significant increase in payload capabilities, thereby giving the submarine more of the one thing that is always at a premium, space.

One possible use for the advanced sail is as the landing pad for modular payloads. Holding strike, SOF, or intelligence, surveillance, and reconnaissance (ISR) systems, modular payloads will be easily swappable--allowing pre-positioned packages that will provide deploying submarines with the right tools for their diverse missions.

Continued U.S. Maritime Dominance

Virginia's inherent deep water capabilities and its enhanced littoral and offensive strike capabilities, manifested in its vastly improved CCSM design and layout, reconfigurable torpedo room, and additional payload, sensors, and SOF support development, and increased energy from the reactor, will provide for continued U.S. maritime dominance. With CAD/CAM for the design and manufacturing process, the modular construction approach, commercial-off-the-shelf technology, and COATS, Virginia will be transformational for the future requirements of combatant commanders. The advanced sail and its additional weapons stowage will further the Virginia class's strong attributes within Sea Power 21. This combination of current and future capability, brought together using affordable design and construction techniques, will provide the U.S. Submarine Force with the "right stuff" to fight and win the global war on terror and America's future wars. *

Capt. John S. Heffron is the Navy's Virginia-class submarine program manager.