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TRIDENT Hull and Missile Life
Extensions Approved

Submarine Rescue -
Past, Present, and Future

Unmanned Undersea
Vehicle "Underway"
for Testing

New Littoral Undersea
Surveillance System
Completes Successful Sea Test

TRIDENT Hull and
Missile Life Extensions Approved

Since 1960, the blue and gold crews of the Fleet Ballistic Missile Submarine (SSBN) force have conducted more than 3,500 patrols. The original “41 for Freedom” served our nation well, and today’s 18 Tridents are worthy successors to the early SSBNs. USS Tennessee (SSBN-734) completed the U. S. Navy’s 3,000th strategic deterrent patrol in April 1992. Recently, USS Michigan (SSBN-727) completed the 500th Trident patrol, and the lead ship of the class, USS Ohio (SSBN-726), recently completed her 50th.

The future of today’s SSBN fleet is based on the Nuclear Posture Review (NPR) of 1994. That review determined that 14 Trident II D-5 SSBNs in two oceans would provide the Submarine-Launched Ballistic Missile (SLBM) portion of the deterrent for the future. Once the second Strategic Arms Reduction Treaty (START II) is ratified, the Navy plans to remove the first four Trident submarines from strategic service, two in 2002 and two in 2003, in order to comply with the launcher and warhead-reduction requirements of the treaty.

The remaining four Trident I submarines, based in Bangor and now armed with the Trident C-4 missile, will be backfitted to carry the newer and more capable Trident II D-5 missile, and all 14 will receive refueling overhauls at 20 years of service. The refuelings are currently planned for the Puget Sound Naval Shipyard in Bremerton, Washington, and the Norfolk Naval Shipyard in Norfolk, Virginia. The D-5 backfit conversions are all planned for the Puget Sound Naval Shipyard, and the shore installations at Bangor, Washington, are also being upgraded to support the D-5 missile on the West Coast.

The 14 D-5 SSBN force will continue to patrol in both the Atlantic and Pacific after a rebalancing of fleet assets based on operational considerations. The Tridents will operate for another 20 years after refueling, since those ships’ hull lives have recently been extended to 42 years: two 20-year operating cycles separated by a two-year refueling overhaul. This unprecedented increase in the hull life of a whole submarine class has been made possible by Trident’s unique maintenance plan, which includes the regular replacement and overhaul of key components and an intense 35-day refit period following each patrol.

Although the D-5 missiles were designed with a 20-year lifetime, they are expected to last for 25 to 30 years. With Trident submarine hulls now lasting 42 years, however, there is an obvious mismatch in longevity. The Navy’s Strategic Systems Program Office (SSPO) is currently studying alternatives to extend the life or replace the existing D-5 missiles using improved technology. This would ensure the survival of the nation’s at-sea strategic deterrent well into the next century.

Providing 54 percent of the nation’s strategic warheads on a day-to-day basis, the Navy’s SSBN fleet requires only three percent of the Navy budget and little more than one percent of Navy personnel. For the United States, this is a bargain price for the most secure and credible part of all America’s deterrent forces.

LCDR Bob Aronson and LCDR Mike Woods (CNO Staff)

Rescue -

Past, Present, and Future

Past: For almost 100 years now, U. S. submarines have accomplished a wide variety of missions while establishing an excellent safety record. From the intelligence-gathering missions and SSBN patrols of the Cold War, to the launching of Tomahawk land-attack cruise missiles during the 1991 Gulf War, the Submarine Force has operated in all oceans under a broad range of environmental and tactical conditions. Submarines have always had a strong commitment to safety, which is reflected in their construction, emphasis on maintenance, training, and the sense of personal responsibility ingrained in every member of the ship’s crew. Nonetheless, the possibility still exists that a submarine may experience a casualty that requires outside assistance and the rescue of personnel.

Motivated by lessons learned from the loss of the USS Thresher (SSN-593) in 1963, the Deep Submergence Rescue (DSRV) program was designed to fill the need for a system that could respond rapidly to similar emergencies. DSRV-1, Mystic, and DSRV-2, Avalon, were placed in “Service Special” in 1971 and 1972, respectively. They remain in full service today, providing both the United States and its allies a worldwide, quick-response submarine rescue capability unmatched by any other nation. The DSRVs have served for over 27 years, and thanks to improvements in reliability and the success of several cost-reduction programs, they will continue to do so for the foreseeable future.

Present: Today, the crew of the Navy’s DSRVs and the officers and enlisted personnel of the Submarine Rescue Unit live with the realization that they may be called upon at any moment to respond to situations where lives are at stake. One of the Navy’s two Mystic-class DSRVs is kept in readiness at all times to respond immediately to potential submarine casualties, with the objective of arriving on scene within 72 hours of a mishap. In standby status, the San Diego-based units are prepared to load more than 200,000 pounds of equipment, including a 40-ton DSRV, onto a C-5B Galaxy aircraft and depart on four hours’ notice for any of 90 qualified rescue ports around the world. To maintain their “Rescue Ready” status, they exercise continually using both underway and in-port training to hone their skills in submarine rescue techniques, cargo handling, seamanship, contingency planning, and rapid deployment. All maintenance and training are planned around a rigid response time requirement, and as a result, since 1977 there has always been a DSRV ready to react to any potential submarine mishap.

The crew of DSRV-2 Avalon convincingly demonstrated their readiness and versatility during the most recent NATO SORBET ROYAL exercise in 1996. The DSRV was launched from the after deck of the USS Sand Lance (SSN-660) and successfully demonstrated the ability to locate a simulated disabled submarine (DISSUB) on the bottom of a Norwegian fjord and transfer rescued personnel to a mother submarine. During a period of five days, Avalon and its crew successfully exercised their rescue procedures on simulated DISSUBs representing four different classes of NATO submarines, and proved that the U. S. submarine rescue system is ready today to do its job.

Future: The likelihood of continuing budget reductions and the opportunities offered by advanced technology have spurred development of new concepts for a next-generation submarine rescue system. Alternatives to the existing approach are under evaluation with the goal of simplifying the existing DSRV support infrastructure and providing a submarine rescue capability with reduced life-cycle cost. The present DSRV support program, designed and implemented to accommodate the high submarine operating tempos of the Cold War era, is costly by today’s budget standards and subject to stringent certification requirements. Rescue systems that operate from surface ships of opportunity and deploy a simpler remotely operated vehicle with only two life support technicians are under development. This portable, modular system would be transported to the seaport nearest the rescue area and deployed on a surface ship pre-positioned there by rescue authorities. Once on scene, rescue personnel would launch the vehicle from the surface, mate it with the disabled submarine, and transport the crew to safety.

The most challenging new requirement for the next-generation system is providing a capability to treat or safely transport personnel who have been exposed to hyperbaric (high-pressure) conditions while awaiting rescue. The ability to mount pressurized rescue operations has been lacking in the current DSRV system since the decommissioning of the two Pigeon (ASR-21)-class submarine rescue ships in 1995. To satisfy this need, the next-generation submarine rescue system will likely include integral surface decompression chambers. Also, biomedical research into hyperbaric phenomena and resulting new decompression techniques are allowing this shortfall to be addressed in the interim. A pending modification to the DSRVs will provide a stand-alone capability to decompress rescued crewman from up to five atmospheres before transferring them to the mother submarine. Overall, transitioning submarine rescue to this new system will not only provide a more flexible and capable submarine rescue system, but will also save the Submarine Force millions of dollars per year.

CDR Mike Vermette, USN (Ret.)

Undersea Vehicle

"Underway" for

In June 1998, the Navy successfully demonstrated its future unmanned underwater vehicle, the Near-term Mine Reconnaissance System (NMRS). Participating in the Joint Countermine Advanced Concept Technology Demonstration (JCM ACTD) held under NATO auspices off Stephenville, Newfoundland. NMRS was part of a large-scale amphibious warfare exercise designed to showcase emerging shallow water mine warfare technologies. The event was the culmination of a series of operational tests and demonstrations that NMRS had been undergoing since March in preparation for entering service in fiscal year 1999. NMRS is an interim system, which will bring a much-needed organic mine warfare capability to the Submarine Force. In configuration, it is a tethered, torpedo-like vehicle intended for launch and retrieval through a submarine torpedo tube. The Long-term Mine Reconnaissance System (LMRS), the follow-on to NMRS, will be far more capable, and together, these systems will represent the Navy’s only covert mine hunting capability.

NMRS vehicle, shown above, being recovered by a surface vessel after testing.
When the system is operational, launch and retrieval will be through a submarine torpedo tube.

The NMRS Operational Prototype commenced its at-sea test period in March 1998 at the Dabob Bay Test Range in Keyport, Washington. The UUV Program Office (NAVSEA PMS403) and Northrop Grumman Corporation oversaw the execution and analysis of a detailed series of tests assessing vehicle and drogue stability, hydrodynamic control, navigation, and sensor performance. In order to demonstrate readiness to participate in the ACTD, the field team was required to complete a carefully defined set of NMRS operating objectives within a limited time frame.

The first phase of testing was completed satisfactorily, with four trial sorties through a test minefield seeded at the bottom of Dabob Bay. Both the Forward Looking Sonar (FLS) and Side Looking Sonar (SLS) were able to locate all mineshapes in the field with a high degree of accuracy. Images provided by the SLS allowed operators to classify bottom objects as mine-like or not. Also during this test phase, eight members of the NMRS Navy Cadre began an on-the-job training period in which they gained experience in system operations and maintenance. The Cadre, a detachment under the Commander, Submarine Development Squadron Five in San Diego, California, will be tasked with operation of the NMRS once it reaches the Fleet.

On 1 May 1998, after a detailed review of test results, the NMRS team temporarily secured from range testing to participate in the JCM ACTD. The system was packaged and shipped to the Woods Hole Oceanographic Institution (WHOI), where it was loaded on board the Melville-class oceanographic research vessel Knorr, a 279-foot research ship that serves as a support platform for NMRS operations.

Deploying approximately a dozen new technology systems at various levels of maturity, the JCM ACTD set out to demonstrate a capability to conduct seamless Mine Countermeasures (MCM) operations by space, air, surface, and subsurface platforms. The ACTD was set within the context of a larger NATO-led exercise designated MARCOT/Unified Spirit 98, and its principal purpose was to determine the military utility of generating new MCM data products and using them in combination with legacy systems.

During the demonstration, the NMRS conducted five mine reconnaissance and survey sorties both in deep water areas, with depths greater than 200 feet, and in shallow water (less than 200 feet) with varying bottom types. Since NMRS is designed to operate from a submarine torpedo tube, new procedures were developed to support surface launch and recovery from the research vessel. Navy Cadre members constructed all sortie plans using available information provided about the area and anticipated threat. Ultimately, all taskings were successfully completed, and the NMRS logged more than ten hours of operational search time. Suspected mine-like objects were reported using standard mine warfare messages after detailed reconstruction and review of sonar data from the sorties.

The Navy Cadre benefited particularly from their participation with NMRS in the ACTD. All members of the team gained a better understanding of the concept of operations in a mine reconnaissance scenario, options for NMRS tasking, system operations, data analysis, and message reporting requirements. Overall, this unique environment provided the operators with additional confidence that NMRS will meet or exceed its overall performance objectives and that it will operate reliably under realistic conditions. All indications are that NMRS is a solid warfighting asset that brings significant capabilities to both the submarine and mine warfare communities.

In July, the system returned to Dabob Bay to begin a second phase of testing that focuses on launch and recovery operations. Testing from a Los Angeles-class SSN is planned for January 1999.

Rick Thornton, PMS403, Unmanned Undersea Vehicles

New Littoral Undersea Surveillance System Completes Successful Sea Test

The Advanced Deployable System (ADS) is a passive acoustic undersea surveillance system designed for rapid deployment in littoral areas for the detection, classification, localization, and tracking of both underwater and surface targets. Unlike earlier deepwater systems that take months to deploy, ADS can be installed within significantly shorter time frames in response to quickly evolving political and military situations along coastal areas of interest. The key sensors are battery-powered disposable hydrophone arrays that can be deployed from ships of opportunity. Lightweight fiber-optic cables interconnect the arrays at sea and bring data ashore in real time. Because of its modular configuration, the same basic equipment can be used to create sensor fields of varying shape and density for area search, or be configured as a trip-wire or barrier, as shown above.

In March 1998, ADS accomplished a key milestone when a complete, integrated ADS system was deployed for the first time. For this major event, which occurred in Puget Sound, Washington, the Space and Naval Warfare Systems Command (SPAWAR) successfully deployed two fiber-optically-cabled underwater acoustic sensor arrays and performed real-time signal processing of the acoustic data ashore. This test was intended as the first opportunity to bring together all segments of the ADS program to plan, deploy, and operate an integrated and functional, mini-system. The three primary ADS sub-systems are:

The Underwater Segment, consisting of the Wet-End Hardware deployed on the sea floor to collect and transmit acoustic data. Both the arrays and the fiber-optic cabling are included here.

The Mission Support Segment,comprising:

  • the Installation Sub-system

  • the Mission Planning Sub-system

  • the Wet-End Inspection and Repair Equipment

The Processing and Analysis System, which records, processes, and displays data from the array and reports contacts to users.

In the Puget Sound test, two arrays were deployed near major shipping channels for both car ferries and cargo ships serving the Port of Seattle. Lockheed Martin Federal Systems and their major subcontractor, Raytheon Systems Company of Mukilteo, Washington, designed and manufactured the underwater hardware, and the Raytheon research vessel Sensor streamed the arrays from the towed deployment vehicle (TDV). The TDV is capable of deploying multiple arrays and their corresponding trunk cables in a single load, which permits a significant area to be “wired for sound” in a single rapid evolution. A shore-based digital signal processing system, housed in a flyaway van, processed acoustic data from the two nodes in real time and successfully detected and tracked a wide variety of surface ships in the Puget Sound test area. The Applied Physics Laboratory of Johns Hopkins University outfitted the processing van. The digital analysis system itself was developed by a consortium of university laboratories and contractors.

The Puget Sound test successfully demonstrated that the current ADS design could be rapidly mobilized, reliably deployed, and effectively operated to perform its mission. While further design work remains, the results show that ADS is ready to proceed with planning and development for its final two developmental tests: the Multi-Node Test and the Fleet Exercise Test. During these events, a more ambitious ADS sensor field will be deployed against surface and subsurface targets, including mining operations. The ADS program is expected to put operational systems into production around fiscal year 2003.

George Shepard, GTE Corporation, and John Thornton,
PMW183, Space and Naval Warfare Systems Command

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