Innovation in Sub Design, at Last
The U.S. Navy and the Defense Advanced Research Projects Agency (DARPA) have initiated what could lead to some of the most innovative developments in U.S. submarine design in some 50 years. In April 1999, DARPA and the Navy will award two or more contracts for "a clean-slate, technically aggressive" look at future submarines, stressing (1) connectivity—the ability to communicate effectively; (2) sensors; (3) payloads; and (4) supporting platforms.
Fifty years ago, the Navy simultaneously developed nuclear propulsion and the high-speed Albacore (AGSS-569) design; the Albacore was authorized in fiscal year 1950, and the first nuclear submarine, the Nautilus (SSN-571), in fiscal year 1951. These technologies—coupled with the quieting and sonar-torpedo arrangement of the Thresher (SSN-593) of 1957—became the basis of U.S. submarine hull and propulsion design for the next half-century. Now, under a joint DARPA-Navy memorandum of agreement, the two organizations are sponsoring a broad investigation of future attack submarine (SSN) design concepts to focus on advanced payloads and sensor systems and their implications for platform design. The only aspects of the submarine that will be off limits in this effort are the nuclear reactor and propulsion train.
Details of the project were revealed in Navy-DARPA briefings at a contractor conference in Arlington, Virginia, on 10 December 1998. In short, the plan is for several industrial teams—each with a nuclear submarine builder, one or more firms engaged in weapon or sensor development, and associated groups—to submit proposals for their approach to the project by 16 February 1999. It is expected that each of the two submarine construction yards remaining in the United States—General Dynamics/Electric Boat and Newport News Shipbuilding—will be a member of one or more of the initial contractor teams.
After evaluation of the proposals, the government will award contracts to two or three of the teams on 16 April. These winning teams then will have 18 months to develop their proposals, submitting final reports in the fall of 2000. Each will be paid $5 million for the 18-month effort.
The Navy and DARPA have provided eight examples of revolutionary capabilities as a guide for the contractor teams. These include submarines towing and supporting manned or unmanned submersibles, redesigning submarines to accommodate "bomb bay" type weapon/submersible carriage and to provide more flexible weapon launching, and increased use of off-board sensors. Such features, it is hoped, will permit more flexible weapon and sensor payloads, enabling future boats to play a greater role in ballistic missile defense, task force protection, naval fire support, special operations, and even urban warfare.
These efforts would be applied to the next generation of SSNs that would be constructed after the current Virginia (SSN-774) class. At this time, the Navy plans to construct 30 Virginias, to be authorized through about fiscal year 2015.
The joint Navy-DARPA project is nothing short of remarkable in view of previous efforts by the nuclear propulsion community to stop any attempts by other parts of the Navy or industry to influence submarine design. In the late 1970s, for example, the Office of Naval Research compiled a report on "Proposed Future Submarine Alternatives." When Admiral H. G. Rickover, then head of the Navy's nuclear propulsion program, saw the draft, he had it withdrawn from circulation and destroyed, as was a subsequent Navy-sponsored study of future submarine concepts called CONFORM (for concept formulation). Similarly, an attempt by the Los Alamos National Laboratory in the early 1980s to examine future technologies for advanced submarines was emasculated and quietly buried.
In contrast, the nuclear community apparently is on board for this project. Admiral Frank L. (Skip) Bowman, Director, Naval Nuclear Propulsion, approved the Navy-DARPA agreement to pursue the project, and several senior Navy submarine officers participated in the 10 December industry conference.
The current effort was initiated on the basis of a Defense Science Board task force on submarines of the future chaired by John Stenbit. The task force report, published in June 1998 stressed the future importance of nuclear attack submarines. Among its recommendations, the task force noted:
- The next generation SSN must be a highly capable warship with rapid response capability.
- It should have flexible payload interfaces with the water, not torpedo tubes, VLS [vertical launch system] and other special-purpose interfaces
- It should not constrain the shape and size of weapons, auxiliary vehicles, and other payloads when they are used
The Stenbit panel was particularly concerned that existing SSN weapon launchers were limited to 21-inch-diameter torpedo tubes, 21-inch VLS cells, and smaller diameter countermeasures ejectors. By comparison, Russian attack submarines have both 21-inch and 26 1/2-inch torpedo tubes, plus—in some units (SSG/SSGN)—large diameter missile launching tubes.
Both the Defense Science Board's report and the Navy DARPA briefing for the industry stressed that the Virginia/SSN program should continue and evolve: "We should not stop an effective program until we have a superior replacement," and "We need to get comfortable with the `flexible interface with the water,' and we need to design and test it."
The next-generation SSN should be a large, nuclear submarine, according to the panel, because "we need to cover the world from the U.S. [at] high transit speed, [with] independent logistics, and endurance," and "we need to have flexible payloads," meaning a large submarine with a hull 33-39 feet in diameter. However, this submarine must be a combat ship and not simply a mother to long-range weapons, sensors, submersibles, and other systems.
The panel recommended against the United States developing diesel submarines, but it noted:
[W]e must learn from the development of such ships for
- Technology infusion
- Threat understanding
- Operational development
- Training and tactics for close-range engagements
This new U.S. effort to enhance SSN payload and sensor capabilities comes just in time. Submarine payloads are relatively small and hence expensive in comparison to modern surface warships (see Table 1). In the past, this asymmetry was not overly important as attack submarines were not considered as platforms for attacking shore targets. But in the U.S. Navy's ". . . From the Sea" strategy, the SSN is being advanced by the submarine community as a principal platform for strikes against shore targets. In addition, surface ships now are armed with 5-inch guns, which are being upgraded, and can operate helicopters and unmanned aerial vehicles.
On the other hand, surface ships are increasingly vulnerable to detection systems and weapons that are being widely proliferated. This will be especially true in littoral operations, which will limit their operating areas. Submarines, obviously, have much greater stealth—but at what cost?
There are proposals to convert two to four Tridents to cruise missile ships/special operations submarines. Such conversions, however, probably will be too costly for near-term budgets and hence are unlikely to be carried out. There also are operational considerations that discourage such multipurpose submarines.
Thus, the Navy-DARPA project offers the promise of more effective attack submarines with a more important role in future naval operations.
The Name Game, Round Two
In one of his last acts before leaving office in November 1998, Secretary of the Navy John Dalton further confused the policy for naming submarines, assigning the names Virginia (SSN-774) and Texas (SSN-775) to the first two New Attack Submarines (NSSNs).
This follows the jumbled naming scheme for the three boats of the previous class. The Seawolf (SSN-21) carries a traditional marine life name that was borne by three earlier U.S. submarines; the Connecticut (SSN-22) has a state name, previously the name source for battleships, cruisers, and ballistic missile submarines; and the Jimmy Carter (SSN-23) was named for a former president and patron of Mr. Dalton.
Virginia was an obvious choice. Mr. Dalton already had named the SSN-22 for one of the two states possessing a submarine construction yard; it was only fair to designate a namesake for the other. A more immediate reason may have been the recent appointment of Senator John Warner of Virginia as chairman of the powerful Senate Armed Services Committee.
Naming a submarine to honor a president or the state of a newly appointed congressional leader has precedent. Admiral H. G. Rickover, long-time head of the Navy's nuclear propulsion program, initiated the practice of naming submarines for persons by honoring members of Congress who had supported his programs: William H. Bates (SSN-680), Glenard P. Lipscomb (SSN-685), L. Mendel Rivers (SSN-686), and Richard B. Russell (SSN-687).
One other SSN carries a person's name: In 1983, then-Secretary of the Navy John Lehman directed that SSN-705 be named Hyman G. Rickover, for Admiral Rickover, whom he had helped force to leave the Navy in January 1982. Secretary Lehman's action was intended to prevent Congress from naming an aircraft carrier for the admiral.
Thus, today's fleet has attack submarines named for marine life, cities, states, a former president, members of Congress, and Admiral Rickover. Confusing, isn't it?