"Forward…From the Sea" shifted the focus of the naval services from blue-water operations toward power projection in the littorals. This dramatic change in the Navy's strategic concept has made it necessary to examine critically the capabilities required by our surface ships in this new medium-specifically, the role of the Spruance-class destroyer.
In 1975, when the Spruance class first entered the fleet, its primary mission was antisubmarine warfare (ASW) protection for the carrier battle group or other mission-essential units. Today the missions assigned to the Spruances have been modified significantly, and expanded with the design, procurement, and installation of new weapon systems. Although ASW, now called undersea warfare (USW), is still a primary mission, the installation of the Tomahawk missile system has added another primary mission: strike warfare. The Spruances' missions have been expanded greatly with the addition of the vertical launch system (VLS) and the Tomahawk missile.
The VLS-equipped Spruance class has proven itself to be the leading strike platform for surface combatants. During Desert Storm, the Spruances launched 112 of the 288 Tomahawks employed. The Fife (DD-991) launched more than any other platform-60 missiles. Combat commanders now rely on the Spruance destroyers as primary strike platforms in the Arabian Sea. They also rely heavily on the Spruances in the USW role.
As Russian and German diesel-powered submarine sales to Third World countries continue, the Spruance-class destroyer will assume more of the mission of finding and destroying these submarines in any future conflict. Even though the Arleigh Burke (DDG-5 1)-class is a superb USW platform, its Aegis system is optimized for battle group air defense and a future role in theater ballistic missile defense. As Arleigh Burkes replace the Oliver Hazard Perry (FFG-7)-class guided-missile frigates and non-VLS upgraded Spruances, the battle group USW mission will fall almost exclusively upon the remaining Spruances.
The Gulf War underscored the flexibility of the Spruance class. During the war several Spruances embarked a small U.S. Army helicopter detachment, to man two OH-58D light-attack night helicopters. These small attack helicopters were used to help recapture Kuwaiti islands held by Iraqi forces. The embarked U.S. Navy SH-60B helicopter used its surface-search radar to vector the Army helicopters to and from their targets. This mission was given to the Spruances along with the FFGs because of their LAMPS Mk III capabilities, and also because the Aegis ships were too busy coordinating the joint air picture. In addition, the Spruance-class destroyers acted as mine countermeasures (MCM) mother ships-providing fuel, food, and water to these ships while at sea, allowing the MCM force to stay on station longer.
As downsizing tapers off and we enter a period of relative stability in fleet size and composition, now is the time to modernize the Spruance class and to look ahead at ways to adapt it to fighting in the littorals. With the continued push forward with the development of new surface combatants such as the Flight IIA Arleigh Burke, the Arsenal Ship, and SC-21, care must be taken not to compromise the combat effectiveness and survivability of the present platforms. The surface combatants of today must not be sacrificed in a misguided effort to buy one more ship for tomorrow.
The Spruances began to enter the fleet early in 1975. At present, the projected decommissioning of VLS-equipped Spruance class ships is between 2018-2020. This adds roughly 15 years to the original 30-year service life of the ship. Even though the Spruance class is only half way through its service life, it already is beginning to show signs of age. For the class to reach its full service life, it must be modernized.
First, we must determine which ships are worth modernizing. Of the 31 Spruances in the fleet, 23 are VLS equipped. Of these 23 VLS destroyers, 12 are Outboard capable, equipped to exploit enemy high-frequency electronic signals. Of these 12 ships, only 4 have the dual RAST (recovery, assist, secure, and traverse) system. The dual RAST systems allows these select ships to operate two SH-60B helicopters. For the Spruances to operate offensively against the emerging diesel submarine threat in a shallow-water environment confronted in littoral areas, they must be equipped with two helicopters and a towed array sonar system. At first glance, only 4 of 31 Spruances appear to be worth modernizing. It is now anticipated that two or three Arleigh Burke-class guided-missile destroyers will be authorized each fiscal year out to 2004, with the first SC-21 being authorized in 2003 and commissioned in 2008. Assuming that SC-21 is intended to replace the Spruance and the Oliver Hazard Perry classes, a large gap will exist in both strike and USW capabilities. Therefore, more than four Spruances must be modernized in order to maintain adequate force levels and mission capabilities.
If two SC-21s are authorized each year from 2005 to 2020 (the probable decommissioning of the last Spruance) 33 SC-21s would be built. Of the 51 FFG-7s in the fleet only 12 are scheduled to be in service until 2019, of which only three will be at sea after 2014. Using these 12 frigates plus the VLS Spruances as a one-for-one replacement by SC-21, the number of Spruances requiring modernization is 21. Adding the large strike capability (not available on the FFG-7s), the versatility of the platform, and the undersea warfare capabilities of the Spruance, all 23 VLS Spruances must be modernized and adapted to fight in the littoral to maintain the status quo in ship force levels.
The modernization of the Spruance class can be broken down into two different sets:
- Engineering and damage control
- Combat systems
Engineering and Damage Control
All ships in the class should be converted to an all-electric configuration. The current waste heat boilers have consistently been a source of major maintenance and manpower consumption. At present, only the Spruance (DD-963) has been modified to this configuration. In converting the ships to an all-electric configuration, it is necessary to replace the existing two stage flash-type distilling plants. These plants should be replaced by reverse osmosis distillers. These high-capacity distilling plants would enable single plant operation, with the other available for standby use.
- Replace the outdated control air system (COAS) clutch-brake system by the newer, simpler, and much more reliable synchronous self-shifting (Triple "S") overrunning clutch (used on the Ticonderoga-class cruiser).
- Replace the current fuel oil purifiers with new self-cleaning fuel oil purifiers.
- Replace the current Allison 501-K17 gas turbine engine with a more efficient model or design. Fabricate and install a new reduction gear between the gas turbine engine and the generator set to allow the engine to run more efficiently at a higher speed.
- Install one intercooled recuperating (ICR) gas-turbine engine in each ship of the class to allow for maximum fuel efficiency while at trail shaft and thus dramatically decrease the life-cycle cost of the ship.
- Improve the aqueous fire-fighting foam (AFFF) stations on the ships damage control decks. (Such improvements should include, but not be limited to, larger storage tanks to prevent the possibility of hose teams running out of AFFF while fighting fires in main spaces. The use of an AFFF loop around the main spaces should also be considered.)
Chilled water (CW) for any ship is the "blood" of most combat systems. A major overhaul of the Spruance's CW distribution system must be performed to prevent the loss of vital combat systems should the ship receive damage.
At present, diagrams for the CW system are inadequate or nonexistent, making it extremely difficult for ship's personnel to isolate damage. In addition, existing CW piping is not separated into loops until entering combat system spaces well above the damage control deck. Separate loops for the CW system should begin on the main deck in addition to the CW loops already present in combat system spaces.
Combat Systems Recommendations
The Rolling Airframe Missile (RAM) is the Navy's solution for the Spruance class to defend against cruise-missile attack. An accelerated delivery of the RAM system to the 23 VLS Spruances must be accomplished to equip these ships better for the littoral environment.
The retirement of the battleships severely limited the capability of U.S. Navy forces to provide the Marine Corps with long-range gunfire support for amphibious operations. The Marine Corps' Sea Dragon program uses small three- or four- man teams to provide real-time targeting data to ships. No ship in the Navy can support such a mission requirement today. The answer lies in exploiting the new improvements in the existing 5-inch gun with the Extended Range Guided Munition (EGRM) round. The use of rocket-assisted smart munitions to destroy targets designated by Sea Dragon teams is a natural evolution of the Spruances' gunfire support mission. At present, the upgrade of the 5-inch gun is scheduled to begin with DDG89. With the Arleigh Burke class having only one 5-inch gun, it requires twice as many ships to provide support for troops ashore when compared to the Spruances with two 5-inch guns.
As the Spruances move closer to shore in the littorals, the replacement of the existing two-dimensional air search radar with a three-dimensional radar should be considered. This would provide earlier warning of low-flying aircraft and cruise missiles coming from landward, and, with the cooperative engagement concept becoming reality, the air picture transmitted by a Spruance operating close to shore would enable Aegis platforms located farther out to sea to launch surface-to-air missiles before making radar contact from their own ships.
With active sonar ranges in most littoral regions exceeding the nominal passive ranges for diesel submarines, the upgrade of the existing SQS-53B active sonar to the greatly improved SQS-53C is required. This upgrade will enhance significantly the Spruances' ability to hunt and destroy diesel submarines in the shallow-water regions of the world, while maintaining its premier open-ocean USW capability.
Lessons Learned during the Laboon's TSST
The Total Ship Survivability Trial (TSST) is described as a "super" final evaluation problem. The TSST assumes the ship has been hit with conventional weapons, simulates damage effects (fire, flooding, equipment damage, and crew casualties), and demonstrates both fight-through and fight-hurt capabilities, to include firing weapons. The TSST has three primary objectives:
- Survivability: Evaluate ship design, equipment/systems, and crew survivability.
- Design: Evaluate ability to contain damage, fight-through, reconfigure vital systems, and counter the next threat.
- Recommendations: Identify potential design, documentation, and training improvements to enhance survivability (evaluate casualties and casualty treatment).
The principal documentation and training recommendations made from the TSST of the Laboon (DDG-58) Aegis guided-missile destroyer tie in closely to the modernization improvements mentioned earlier. These recommendations not only deal with hardware improvements, but also with training, and thus fighting the ship. Of the 120 lessons learned from the Laboon's TSST the following recommendations should be applied to the Spruance class, to enhance survivability and combat effectiveness in the littorals:
- Standardize combat systems operations sequencing system, engineering operations sequencing system, and damage control documentation, especially for auxiliary systems (chilled water, electronics cooling water, low-pressure air), into a combined operating sequencing system.
- The engineering operations sequencing system and engineering operating casualty control system should address preparations for a combat environment and combat casualty control instead of peacetime cruising.
- Expand the scope of the engineering operations sequencing system and engineering operating casualty control system to include integrated chilled water documentation for engineering, combat-system, and damage-control personnel.
- Damage Control lockers should hold all necessary documentation to allow for rapid and effective isolation of air and water pipe ruptures.
- Develop documentation to support electrical and mechanical isolation ship-wide.
- Provide realistic integrated casualty control training.
The Spruance-class destroyers' missions have continued to expand, change, and adapt as technology has advanced and perceived threats have varied. This class is now at a crossroads. As the roles and missions of surface combatants shift from open ocean to the littorals, Spruance destroyers have assumed the role of the premier strike and undersea warfare platform. To increase the combat effectiveness and survivability of these ships in the littorals, an aggressive modernization program should be undertaken as the Spruances approach middle age in their service lives.
Lieutenant Haas graduated from the U.S. Naval Academy in 1990 and was assigned to the Elliot (DD-967) as auxiliaries officer and main propulsion assistant. He received a master of science degree in mechanical engineering from the Naval Postgraduate School, concentrating in gas turbine research, and at present, is the prospective engineer officer of the John Hancock (DD-981).