In the seven years since the Soviet Union collapsed, the U.S. Navy has reoriented its strategy and forces to place much greater emphasis on littoral warfare. Recognizing that the majority of regional conflicts would probably occur in or near coastal areas, since that is where most of the world's population and commerce is found, the sea service has made effective execution of littoral operations the centerpiece of its future plans. The shift in emphasis from "blue water" to "brown water" operations has been reflected in a series of major doctrinal pronouncements, beginning with "From the Sea..." in 1992.

One challenge in implementing this vision of future roles and missions has been that much of the current fleet and its associated equipment was designed primarily for operations in the open seas. Although the Navy has always expended a significant portion of its budget on amphibious and other littoral operations, during the Cold War it was focused mainly on countering threats posed by the Soviet Red Navy, and most such threats were expected to arise away from coastal areas. Now the Navy must adapt Cold War weapon systems and warfighting concepts to the demands of operating in close proximity to potentially hostile littoral powers, and learn how to project power ashore without incurring unacceptable risks.

Eventually the Navy will develop new generations of warships that are optimized for littoral operations. But with current shipbuilding budgets only funding four or five new combatants annually, it may be decades before Cold War systems are fully replaced. In the near term, there is no alternative to modifying some of those systems for littoral warfare.

One concept that is rapidly gaining support among senior Navy officers and civilian strategists is the Trident SSGN, a plan to reconfigure ballistic-missile submarines for conventional land-attack missions. If implemented, the Trident SSGN would provide a highly survivable platform capable of carrying as many Tomahawk cruise missiles as an entire carrier battle group. Such a system could participate in regional conflicts from the first day of hostilities, countering the initial acts of aggression and preparing the battle space for the arrival of other U.S. forces. Many analysts believe the Trident SSGN would be more operationally viable and affordable than other littoral-warfare systems currently under consideration.
 

Origin of the Concept

The Trident SSGN concept traces its origins to the convergence of several strains in recent naval thinking. First of all, there was the shift of emphasis in military planning from global east-west war to "major regional contingencies," a change formalized in the 1993 Bottom-Up Review. Second, there was the Navy's growing interest in littoral operations, which was accompanied by a recognition that the fleet needed more conventional firepower -- particularly long range, highly precise firepower -- for influencing events ashore. Third, there was the increasing awareness that with Cold War demobilization still in progress nearly a decade after the dissolution of the Warsaw Pact, a planned surge in procurement funding for recapitalization of the fleet might never materialize.

All three concerns gave rise to new ideas about how to bolster the availability of firepower in littoral regions without incurring major new shipbuilding expenses. The leading concept currently being explored is the arsenal ship, a relatively inexpensive platform equipped with hundreds of land-attack munitions that would be permanently forward-deployed, much like a maritime prepositioning ship, for quick reaction to regional conflicts. Unlike the multimission combatants that form the core of the current fleet, the arsenal ship would have minimal on-board sensors and self-defense capability. The command, reconnaissance and protection for its weapons would be provided by personnel aboard other warships.

The Navy and Advanced Research Projects Agency are jointly developing an arsenal-ship prototype, and a total of six operational vessels may eventually be funded. Development contracts were awarded to three industry teams in January, with the expectation that one team's design will be selected in 1998 for actual construction. However, even before the awards were made, there was growing disagreement about the operational utility of the arsenal ship concept. Rep. Ike Skelton (D-MO), an influential member of the House National Security Committee, complained that the arsenal ship "at best would appear to be a sitting duck." Internal Navy analyses seemed to agree: the arsenal ship would have to stay well outside war zones until littoral seas and airspace were secure, a process that might take weeks. Support for the program began to wane among Navy leaders, and in March the head of the nation's biggest shipyard confided to reporters that he did not expect production of the arsenal ship to continue beyond the initial prototype.

A different approach to implementing the arsenal ship concept then began emerging within the Navy. This approach involved modifying four Trident ballistic-missile submarines to carry conventional land-attack missiles and an appropriate suite of sensors and communications links for autonomously participating in littoral warfare. The U.S. had built a total of eighteen Trident SSBNs between 1974 and 1997, each one of which was designed to carry 24 multiple-warhead, nuclear missiles. Measured in terms of its firepower, the Trident was the most potent warship in history -- so potent in fact, that it was not possible to retain all eighteen boats in the force once the U.S. and Russia implemented the START II strategic arms reduction agreement. The U.S. therefore planned to remove the four oldest Tridents (the Ohio, Michigan, Florida and Georgia) from the nuclear force and either decommission them or adapt them to some other purpose.

The very large weapons-carrying volume of the Tridents makes them better-suited to an arsenal-ship type role than other classes of submarines. Like all nuclear-powered submarines, the Tridents are intrinsically stealthy when submerged and have sufficient undersea endurance for extended autonomous operations (a typical undersea tour in the nuclear tour deterrence role is seventy days). Because the submarines are already built and paid for, they are a relatively inexpensive option for increasing conventional land-attack capabilities, even when the costs of modification and nuclear refueling are included. By the spring of 1997, the Navy had developed detailed plans for how such a system might contribute to littoral warfare.
 

How It Would Work

According to internal Navy documents, the four Tridents would be modified to conduct both conventional land strikes and special-operations missions. Twenty-two of the ballistic-missile tubes would be reconfigured so that each could hold either six Tomahawk land-attack cruise missiles or six naval variants of the Army's Advanced Tactical Missile System (ATACMS, or NTACMS in the naval version). Tomahawks are capable of hitting interior land targets up to 1,000 nm distant from their launch point with a variety of warheads tailored to different missions. Navy sources indicate that the introduction of increased data-rate equipment linked to off-board sensors will enable the crews of the Trident SSGNs to retarget the highly maneuverable Tomahawks "in a few seconds."

NTACMS is a short-range ballistic missile with similar volume to Tomahawk that can deliver anti-personnel or anti-armor warheads to distances of over 100 nm. within five minutes. Future naval variants may be able to reach as far as 270 nm. In addition to advanced precision-guided warheads such as the Brilliant Antitank (BAT) system, NTACMS is also expected to have sufficient kinetic force to destroy buried, hardened command centers -- a particularly challenging target set that the Navy has had difficulty addressing effectively in the past. The Trident SSGN would carry a mix of 132 Tomakawks and NTACMS, all of which could be launched while the vessel remained submerged. According to sources, variations in the NTACMS flight path would foil enemy efforts to trace the trajectory back to its source.

The remaining two missile tubes on the Tridents would be modified to interface with two Advanced SEAL Delivery Systems, small submarines attached to the Tridents' external hull that can deliver eight special-operations personnel up to 125 nm from the mother vessel to conduct missions during or before hostilities. SEAL missions are highly sensitive, but Navy officials indicate that some of the missions could facilitate targeting of the SSGN's missiles.

In order to achieve maximum effectiveness with its weapons, the Trident would be linked to a network of off-board sensors at sea, in the air, and in orbit. These include unmanned aerial vehicles, unmanned undersea vehicles, and the Air Force's JSTARS armor-tracking reconnaissance aircraft. Because it would be linked to a network of sophisticated sensors and communications systems, the Trident SSGN would be able to operate effectively in the absence of other Navy vessels -- an important capability for a platform that might be the sole U.S. presence in-theater on the day a regional conflict commences.

The submerged stealth of the Trident SSGN is expected to provide ample protection against airborne threats, although the system would retain many of the self-defense features of a typical attack sub such as sonar and homing torpedoes to counter undersea threats. Tridents are already equipped with much of the necessary technology for undersea defense and tactical operations, although some backfitting of navigation and other equipment would be necessary to enhance shallow-water operating capabilities. Nonetheless, the SSGN would carry ten fewer crew than the SSBN version of the Trident does.

The current concept of operations for the Trident SSGN envisions basing two on each coast at the Trident facilities in Kings Bay, GA and Bangor, WA. This would maximize flexibility for responding to multiple regional contingencies in widely separated locations. Flexibility would be further enhanced by assigning dual crews to each boat, which would enable at least one of the Tridents from each coast to be on station near regional flashpoints 84% of the time (given refit and transit times, the single-crew-per-vessel option would reduce on-station time to about 54%).
 

Numerous Advantages

Senior Navy officials see numerous operational advantages to the Trident SSGN concept. First of all, because it is stealthy it would have the advantage of surprise to amplify the effects of its initial strikes. Second, it does not require secure battle-space in which to operate, and in fact can commence operations such as SEAL insertion prior to the outbreak of hostilities. Third, it will have extensive organic intelligence, reconnaissance and surveillance capability, enabling it to operate autonomously in the absence of support from other naval assets. Fourth, it can be forward-deployed for quick response without being as provocative as major surface combatants. Fifth, its considerable weapons-carrying capacity allows it to deliver a truly devastating blow against aggressors in advance of the arrival of other forces. Sixth, once the follow-on forces arrive, it can be rapidly reloaded to continue participation across all phases of the conflict. Finally, it will be internetted with other military assets to facilitate smooth combined arms and joint operations.

With so many virtues, not to mention the fiscal appeal of affordability, Navy officials are careful not to oversell the Trident SSGN concept. They describe it as a complement to other warfighting platforms rather than a substitute, and caution that like any other system it has its limitations. But these limitations pale before the considerable advantages of adapting a proven system to the military demands of a new era. If START II is ratified as expected, all four Tridents will be removed from strategic service in 2002-2003, freeing them up for new careers as the most powerful and survivable conventional land-attack systems on the seas in the early twenty-first century.