Destroyer Escorts the Cold War
After World War II scores of the damaged and less--capable DEs were scrapped while others were trans-ferred to foreign navies. Hundreds of others were "mothballed" and relatively few were retained in active U.S. Navy service. When the Korean War began in June of 1950 orders went out to activate some of the retired destroyer escorts in addition to hundreds of other Navy ships.
There was little threat from submarines in the Korean conflict because neither North Korea nor Communist China had submarines at the time. Still, there was the possibility that the Soviet Union, which had the world's largest submarine fleet, might enter the conflict in Asia or possibly Europe. In-deed, by 1950 there was evidence that the Soviets were beginning a massive submarine construction effort, one that would peak in the mid-1950s when 90 submarines were launched in a single year.
To counter this threat, the U.S. Navy initiated a new DE-building program. These ships would be more capable than their war-built counterparts and suitable for mass production should the need arise. In addition to a slightly higher speed, they would have improved radars and sonars.
The first of the new ships was the DEALEY, completed in 1954. At about the same time the designation DE was changed from "destroyer escort" to simply "escort ship" to avoid confusion with larger destroyers that were being modified with im-proved anti-submarine weapons and called "escort destroyers" (DDE). Several new escort ships followed on a regular basis as the Navy sought to modernize its ASW forces (with some ships of the DEALEY type being built in Portuguese and Norwegian shipyards for those countries). After 17 generally similar ships had been built between 1954 and 1960, the U.S. Navy intro-duced the BRONSTEIN class which, although only two ships, marked the introduction of several tech-nical innovations to the escort ship category.
The BRONSTEIN and McCLOY, both completed in 1963, were the first DEs to have/the newly developed SQS-26 sonar, a very large underwater detection system. The large sonar dome is mounted at the bow of the ships, as far forward and away from the ships' machinery noises as possible. In addition to being capable of "passive" detection, that is, listening for submarine sounds, this sonar can be "active," transmitting a narrow but powerful beam of sound that is reflected back to the sonar should it encounter an underwater object. The ranges of the sonar, in both passive and active modes, are much greater than previous sonar detection capabilities.
With the improved detection ranges came the requirement for longer-range ASW weapons to take advantage of the increasing distances at which enemy submarines could be found. The depth charge and even the hedgehog are essentially close-in weapons. For long-range ASW the BRONSTEIN and later escort ships have a helicopter capability and ASROC missile launcher.
A small helicopter can be embarked in the es-cort ship and launched when the DEs sonar indi-cates a possible submarine contact. The helicopter is then launched to "localize" the contact and at-tack, generally dropping torpedoes that home in on submarine noises.
The ASROC (for Anti-Submarine ROCket) con-sists of an eight-cell launcher that can fire rocket--assisted torpedoes or nuclear depth charges out sev-eral miles from the ship. The torpedo or depth charge breaks away from the rocket booster and is parachuted to the water near the submarine contact. The torpedo then enters the water, the parachute breaks free, and the torpedo begins an automatic search pattern for submarine noises. In the case of the nuclear depth charge, the weapon enters the water and sinks to a pre-set depth before exploding.
For close-in ASW the BRONSTEIN and other postwar DEs have been fitted with torpedo tubes for "short" acoustic homing torpedoes shorter than the traditional 21-foot-long anti-ship torpedoes that long were standard in the U.S. Navy).
The importance of this type of ship was ad dressed in a 1962 article in the Naval Institute Proceedings by then-Captain Elmo R. Zumwalt (now the Chief of Naval Operations), who wrote that: "The destroyer escort perhaps will be of greatest significance to cold and limited war operations of the future . . . .It will contain minimal competence in all weap-ons systems except for ASW in which it will be superior-using the same equipment as provided to the larger [destroyer] types. It will probably have a top speed of 23 knots and long range capability. It will likely be the workhorse for escort of convoys . . . ."
The BRONSTEIN and McCLOY were followed by 63 additional escort ships that incorporated the large SQS-26 sonar, ASROC, and a helicopter capa-bility: the ten GARCIA class ships and six similar BROOKE class escorts that also have an anti-aircraft missile launcher, 46 of the large KNOX class ships, and the one-of-a-kind GLOVER, used as an anti--submarine research ship. The last units of the KNOX class now are under construction.
Led by the KNOX in September of 1970, several of this class of escort ships have de-ployed to Southeast Asia and participated in the Vietnam conflict. Their accomplishments exceeded expectations with respect to performance and mis-sion versatility. Although the KNOX-class ships were intended primarily for anti submarine operations, the nature of the Vietnam War and the severe reductions in more capable destroyer ships required the escort ships to fulfill many roles generally assigned to general purpose destroyers. These roles included gunfire support for operations ashore, blockade, and pilot recovery in hostile waters.
The relative success of these ships, the changing nature of the Soviet threat to U.S. activities at sea, and the availability of advanced weapon systems have resulted in several programs being undertaken to increase the combat capabilities of the KNOX class ships. Discussed in more detail in subsequent sections of this booklet, these programs include provision of a manned anti submarine helicopter, installation of the Sea Sparrow anti aircraft missile system and a variable depth sonar, and consideration of the Harpoon anti ship missile that could be fired from the ASROC anti submarine launcher.
The last eight of the KNOX-class ocean escorts were completed during 1973 and early 1974. These ships are being constructed by Avondale Ship-yards in Westwego, Louisiana. Currently the Avon-dale yard is the nation's largest builder of escort--type ships for the U.S. Navy and Coast Guard. When the 46 KNOX-class ships were completed the Navy had 65 first-class ocean escorts, ships fitted with the ASROC weapon system, SQS-26 sonar, and a helicopter capability. Several older, less-capable escort ships also were in service during the 1970s, but employed primarily in the naval re-serve training role.
These additions to the KNOX design, already proven by the operations of more than two dozen ships completed by the end of 1972, added to the effectiveness and versatility of the Navy's escort and patrol ships in the coming decades. Including the previous BRONSTEIN, GARCIA, and BROOKE classes, and the planned PF series, the U.S. Navy had some 115 highly effective ocean escort ships by the mid 1980s. These escort ships could be most vital to U.S. interests in future cold war confrontations or in limited or conventional conflicts because of increasing American dependence upon use of the sea for trade, the transportation of energy resources, and military operations.
|Join the GlobalSecurity.org mailing list|