Ohio-class SSGNs: Experimental Test Beds for Future Attack Subs

By HUNTER C. KEETER
Associate Editor

The Navy's new submarine platform, the Ohio-class guided-missile nuclear-powered submarine (SSGN), will perform a dual role for the service's submarine fleet. Bristling with Tomahawk missiles and able to carry 66 special operations forces and their gear, these boats--representing a new type of weapon in the Navy's arsenal--can carry out massive land attack assignments as well as clandestine missions. But the Ohio-class SSGNs also will perform as seagoing test beds for the submarine fleet, operating new technologies and components--and testing new tactics--for other classes of submarines. The successes will be incorporated rapidly into the Jimmy Carter, third of the Seawolf-class, and in the new Virginia-class submarines or the older Los Angeles-class attack boats.

In 2000, the president and Congress agreed to scale back from 18 strategic nuclear-powered ballistic-missile submarines (Ohio-class SSBNs) to 14 boats. The Navy subsequently proposed modifications to create four SSGNs out of four Ohio-class hulls instead of decommissioning them. In addition to providing for as many as 154 Tomahawk missiles, the SSGN modification includes fitting two of the 24 submarine-launched ballistic-missile tubes to accommodate special operations forces' mini-submarines or other vehicles, as well as to provide large-diameter lock-out chambers for entry and exit of the boat while submerged.

At a cost of around $4 billion, the new SSGN conversion draws upon the legacy of the USS Halibut and the Regulus missile program of the 1960s--a marriage of then-experimental technologies: the nuclear-powered submarine and the sea-launched cruise missile. The service plans initially to deploy the USS Ohio and the USS Florida configured for Tomahawk launch and for special operations missions. Later in the program, as the USS Georgia and the USS Michigan are converted, the Navy could introduce SSGN-launched unmanned aerial vehicles (UAVs) and unmanned undersea vehicles (UUVs)--robots that could be used to extend the reach of a host boat's sensors or to deliver weapons, supplies, and surveillance devices.

Since 1998 the Defense Advanced Research Projects Agency and the Navy have worked to hone the technological edge for U.S. submarines. Two industrial teams--the consortia "Team 2020" and "Forward Pass," led by Lockheed Martin and Raytheon, respectively--have supported the payloads and sensors effort, which aims over the long term to improve submarines' abilities to communicate, collect information, navigate, and support special operations forces.

The payloads and sensors initiative has already been linked to the SSGN program. In January 2003 the Navy hosted its first major sea trial experiment--Giant Shadow--with the Florida acting as an SSGN during an event that brought the two industry consortia together to experiment with robotic vehicles, special sensors, and weapons alongside special operations forces during a simulated assault on a Bahamian island. The experiment included using the UAV and UUV in exercises designed to simulate the launch and control of these platforms from the SSGN's command center. Events like Giant Shadow are the precursors to operational efforts with the SSGN, the first of which arrives in 2007.

As test beds for future submarine capability, the four-boat Ohio-class SSGN series presents an opportunity for the Navy to get more out of every dollar it spends on the research and development of new-generation fast attack boats, such as the Virginia class, scheduled to become operational in 2004. They will be the first of a planned 30-boat family of ships that may cost $82 billion to acquire.

"[Using SSGN as a test bed] will be the key in the development of the Virginia class: We have a new tool that we did not plan on early on--it is the SSGN," said Rear Adm. John D. Butler, program executive officer for submarines, on 10 July 2003 during a news conference at the Washington, D.C., Navy Yard. "It is a test asset available to us to test new technologies, test them early on, and then break [them] into the design of the Virginia class. What we learn from the SSGN will be used to help push the envelope for Virginia's next-generation payloads. We will take the investment in SSGN and apply it to our newest fast attack submarines that will be the backbone of the submarine force for decades to come."

During Giant Shadow, the Navy experimented with the large volume of the Trident missile tubes aboard the Florida, using one of these to launch a 38-inch diameter Seahorse UUV developed with the Penn State University's Applied Research Laboratory. This part of experiment Giant Shadow demonstrated that the SSGN will help break the "tyranny of the 21-inch diameter torpedo tube," which limits the size of launch payloads aboard today's attack boats. In the future, the Navy could apply lessons from the SSGN-Trident conversion to develop payload modules that could be inserted into the Virginia-class hull form, allowing larger UUVs and other technologies to be carried. Robotic vehicles developed in the shadow of Seahorse may serve as re-suppliers and transports for special operations forces, or to conduct surveillance and, perhaps, combat missions of their own.

Elsewhere in the fast attack force, SSN Jimmy Carter, scheduled for delivery in December 2004, is outfitted to perform the SSN mission set as well as to host classified experimentation of its own that could influence other submarine payloads and capabilities.

"To complete the triad of new submarine capabilities, we have ... Jimmy Carter, the last of the [three-boat] Seawolf-class," Butler said. "Jimmy Carter will be a submarine like no other; it will carry out all fast attack missions, including ASW [antisubmarine warfare], ASUW [antisurface warfare], strike and ... [special missions], and it will also be able to carry out classified research, development, and experimentation."

A common thread binding the Navy's undersea technology development plan is the use of commercial-off-the-shelf (COTS) hardware and software. The Navy increasingly has moved away from military specifications for its computer systems and relied more on commercial industry for state-of-the-art design and operation of new ships.

"For the Virginia class, we went to COTS and boosted our processing power by more than seven times at one-sixth the development cost we expended on the Seawolf's [BSY-2 combat] system," Butler said. "Furthermore, because we are using commercial components, we can much more readily update our systems, something we have not been able to easily do in the past."

The cost to develop the BSY-2 was unavailable. The total cost of the development of the three-boat Seawolf class, including the BSY-2 effort, was $13.2 billion, at an average per unit cost of $2.8 billion, according to the DoD's Director of Operational Test and Evaluation.

The Virginia class will use commercial computer processing technology to control a photonics mast, the next generation in surveillance capability. Photonics masts use sophisticated camera systems to replace the mirrors and prisms of conventional periscopes.

Unlike a traditional periscope, the photonics mast does not pierce the submarine's hull, which allows boat designers additional architectural freedom. For example, the command center can be located out of line from the sail, whereas periscopes come down through the hull, where the control room must be located. Recently tested at sea aboard the USS Annapolis, a Los Angeles-class boat, the photonics mast has gained favor in the submarine force as a valuable tool using high-resolution color and infrared cameras and displays, and a laser rangefinder to assist in targeting. *