Spruance-class destroyer

The class was originally designed for anti-submarine warfare (ASW) with point defense anti-aircraft warfare (AAW) missiles; upgrades provided anti-ship and land attack capabilities.[2]

The ships were initially controversial, especially among members of the United States Congress who believed that their unimposing looks, with only two guns and an ASROC and Sea Sparrow missile launcher per ship implied that the vessels were weak compared to Soviet designs which carried large numbers of anti-ship missiles. The Spruance-class was also unfavorably compared to earlier U.S. designs which had more visible guns or launchers for the Standard medium range missiles. Despite the criticism they were successful in their intended ASW role due to their seaworthiness, quiet operation, and ability to operate two helicopters.[3]

Six Spruance-class destroyers fitting out, c. May 1975.

The Spruances were much larger than destroyers of that era, being comparable in size to contemporary guided-missile cruisers (CG and CGN) and U.S. Navy light cruisers (CL) in World War II. Their hull dimensions allowed them not only to accommodate a helicopter landing pad, a first for a U.S. Navy destroyer as flight decks were previously only found on frigates and cruisers, they were the first U.S. Navy destroyer/cruiser class to have an enclosed hangar (with space for up to two medium-lift helicopters) which was a considerable improvement over the basic aviation facilities of earlier cruisers.[4] The "Spru-cans" were the first large U.S. Navy ships to use gas turbine propulsion; they had four General Electric LM2500 gas turbines to generate about 80,000 horsepower (60 MW). This configuration (developed in the 1960s by the Royal Canadian Navy for the Iroquois-class destroyers and known as COmbined Gas And Gas, or COGAG) was very successful and used on most subsequent U.S. warships. As of 2010, all U.S. Navy surface combatants (except nuclear-powered aircraft carriers and the LCS-1) use the LM2500 COGAG arrangement, usually with two such turbines per shaft.[5]

The Spruance-class received the "DD" designation in the hull classification symbol system which was previously applied to gun destroyers, though their primary armament as designed was missiles. However their original complement of 8 Sea Sparrow anti-aircraft missiles was only sufficient for point defense, compared to other American destroyers designated as DDG which were designed to provide anti-aircraft warfare screening to the fleet, while some newer DDG ships further added powerful surface-to-surface capabilities. A major update from the mid-1980s added a 61-cell Vertical Launch Missile System (VLS) for the Tomahawk surface-to-surface missile which modernized 24 members of the Spruance-class to a strike destroyer standard, although they remained as DD because they continued to lack the anti-aircraft capabilities of guided-missile cruisers (CG and CGN) and destroyers (DDG).[6]

The entire class of 30 ships was contracted on 23 June 1970 to the Litton-Ingalls shipyard in Pascagoula, Mississippi, under the Total Package Procurement concept originated by the Whiz Kids of Robert McNamara's Pentagon. The idea was to reap the benefits of mass construction, but labor and technical problems caused cost overruns and delayed construction.[7][8]

One additional ship, USS Hayler, was ordered on 29 September 1979. Hayler was originally planned as a DDH (Destroyer, Helicopter) design, which would carry more anti-submarine helicopters than the standard design of the Spruance class. Eventually this plan to build a DDH was scrapped and a slightly modified DD-963 class hull was put in commission.

Four additional ships were built originally for the Iranian Navy with the Mark 26/Standard AAW missile system and commissioned as the Kidds for the U.S. Navy. The Kidd-class destroyers used the same hull as the Spruances but they were more advanced general-purpose ships with significant anti-air warfare capabilities that the Spruance-class lacked. It was once planned to build all of the Spruance class up to this standard, but it was too expensive. A slightly lengthened version of the hull was also used for the Ticonderoga-class cruisers, originally planned as DDG-47-class destroyers but redesignated as cruisers in 1980 to emphasize the additional capability provided by the ships' Aegis combat systems, and their flag facilities suitable for an admiral and his staff.[9]

An air-capable mini V/STOL aircraft carrier with fighters and ASW helicopters based on the Spruance hull was seriously considered but not produced.[10][11]

The Spruance design is modular in nature, allowing for easy installation of entire subsystems within the ship. Although originally designed for anti-submarine warfare, 24 ships of this class were upgraded with the installation of a 61 cell Vertical Launch Missile System (VLS) capable of launching Tomahawk missiles. The remaining seven ships not upgraded were decommissioned early. Deyo was the only Spruance-class destroyer that received the armored box launchers for Tomahawk that also later received the VLS upgrade, while Harry W. Hill was the only one that never received the Tomahawk, having had its VLS upgrade cancelled.

• Merrill served as the Navy's test platform for the Tomahawk Cruise Missile Program receiving armored box launchers and test launching a Tomahawk 19 March 1980. Merrill carried two ABLs and an ASROC launcher into the 1990s until the ASROC launcher was removed.
• David R. Ray tested the RAM system in the 1980s, but had the system removed after the tests.
• Oldendorf was the test platform for the AN/SPQ-9B Anti-ship Missile Defense (ASMD) Firecontrol Radar to be outfitted on the San Antonio-class amphibious transport docks. The AN/SPQ-9B is used to detect all known and projected sea skimming missiles.
• Arthur W. Radford tested the Advanced Enclosed Mast/Sensor system which helped in the mast design of the San Antonio-class amphibious transport dock ships.

At least ten VLS ships, including Cushing, O'Bannon, and Thorn, had a 21 cell RIM-116 Rolling Airframe Missile launcher mounted on the starboard fantail.

Spruance-class destroyers fired 112 land attack Tomahawks during Operation Desert Storm.[12]

In order to save $28 million a year, the Navy accelerated the decommissioning of the Spruance class, though they could have served to 2019 had they been maintained and updated.[13] Despite the recent modifications to the Spruance and Kidd classes, they were still considered expensive and manpower intensive to operate, while the succeeding Arleigh Burke-class were more capable and versatile due to their Aegis combat system while also being more cost-efficient, and by the end of the 1990s many Arleigh Burke-class destroyers had entered the fleet. While the early Flight I Arleigh Burke ships only had a flight deck, Flight IIA and subsequent vessels added the enclosed hangar which made their aviation facilities comparable to the Spruance-class.

The US Navy planned to replace its current destroyers and cruisers with the new Zumwalt-class (DDG-1000) vessels, but the 2010 U.S. Defense budget funded the construction of only three DDG-1000s[14] and production of Arleigh Burke class continued and it became the U.S. Navy's only operational class of destroyers after the USS Cushing was decommissioned on 21 September 2005.[15]

Rather than being preserved in storage like some older classes or offered up for sale to foreign navies, some were broken up and the remaining majority of the class finished their lives as targets in various fleet exercises. The last Spruance-class destroyer on active service, USS Cushing, was decommissioned on 21 September 2005. It was unsuccessfully offered to the Pakistan Navy before being sunk as a target 29 April 2009. The four Kidd-class destroyers were decommissioned in 1998 and were sold to Taiwan in 2005 and 2006.

One notable exception to this fate is the ex–Paul F. Foster which replaced the ex-Decatur in 2005 as the Self Defense Test Ship. The SDTS is remotely-controlled to tow a barge targeted by live weapons. This avoids the safety concerns and other problems associated with manned ship exposure to live weapons.[16][17]