In the popular imagination, destroyers are vessels that were built specifically to defeat submarines. The experience of both world wars, especially in the context of the convoy system, did much to substantiate this impression, but it remains inaccurate. As a class, the destroyer was created before submarines posed any real threat, and traditional destroyers gave a mixed performance in anti-submarine work when this became a major role. During World War II, the true bane of Axis submarines was a specialist vessel, the Destroyer Escort.
Conventional destroyers (designated DD in the U.S. Navy) were created for a different purpose entirely. In the latter years of the nineteenth century, torpedo boats were a real threat to the large and expensive cruisers and pre-dreadnought battleships of the navies of great powers. Destroyers were built as support vessels fast enough to intercept and pursue torpedo boats, but sufficiently well armed to defeat such boats in any contest. The combat roles of the destroyer expanded in the years leading up to World War One, but it remained that they were designed to fight other surface craft, and when they needed to take on an anti-submarine role, it took a fair amount of work to equip them for that role. After the war, destroyer development in all of the major navies proceeded in the direction of making destroyers larger and more heavily armed.
Neither of these characteristics did much to improve their performance against submarines, although the British, American and Japanese destroyers would all need to serve in this capacity during World War II. As the Americans and Japanese only began to experience this need in 1942, it was the British who first considered alternatives to conventional destroyers. Not only were such destroyers equipped mainly for surface engagements, but they were too long and even too fast. Their length meant that it took too long to turn about when a submarine was sighted; as for speed, destroyers intended to protect convoys needed only to be somewhat faster than the ships they were protecting. Additional speed was wasted.
Anticipating the need for convoy work in the last year before the war began, the British had taken some steps already to address these concerns. They created Fast Escort Vessels, such as the Hunt class, which was much shorter than fleet destroyers at just over 280 feet in length. This gave them a better turn radius. Armament was light, with an emphasis on antiaircraft and antisubmarine weapons. The Hunts were not hardy craft, and in the end, their armament was too light, leaving them closer in strength to the kinds of vessels that fleet destroyers were built to defeat in the first place. The Hunts were built in three sub-classes, for a total of 83 vessels.
As merchant losses in the Atlantic mounted, the British turned to America for aid. Trusting in American industry, the British requested additional escort vessels based on the same concept. These new escorts would have a similar length, but offer a more stable firing platform and somewhat heavier armament. Three-inch guns and torpedo tubes would offer the main surface armament, with a dozen anti-aircraft guns to defend against the growing threat from the sky and depth charges and “hedgehog” depth-charge cluster-throwers for use against submarines.
Britain’s original intention was to purchase 300 of these new destroyer escorts (designated DE in the U.S. Navy) at the end of 1941 and the beginning of 1942. Of course, American involvement in World War II stepped up after the Japanese attack on Pearl Harbor; with no comparable vessels already in service in the U.S. Navy, production of the DE series was increased to serve domestic needs. Over 1,000 were meant to be built; 565 were actually built before further construction was canceled, but by then, the Allies were effectively in control of the oceans, and no more Destroyer Escorts were needed.
These escorts were mass-produced in a modular design, and then assembled in port for speed and efficiency. Even so, shortages prevented complete uniformity, and six classes were created as a result. The first, the Evarts (or pattern GMT) conformed most closely to the original British request. Accordingly, it ran to just under 290 feet, and its main surface armaments were three 3” guns. It was propelled by a diesel engine. These three elements defined the various classes, with all five subsequent classes being lengthened to 306 feet. The Buckley (TE), Cannon (DET) and Edsall (FMR) classes shared the main armament of the Evarts, while the Rudderow (TEV) and Butler (WGT) classes mounted two 5” guns instead. Diesel, turboelectric and geared turbine engines were used, depending upon the class.
Britain received 78 DE vessels. Twelve more were eventually given away, six each to France and Brazil. The remainder served in the U.S. Navy, but with American participation in the war, they served the same purpose regardless of the flag under which they served.
Depending upon the engine in use, the destroyer escorts varied in speed between 20 and 25 knots. These speeds were more than adequate, as the role of these vessels was to travel generally at the same speed as the convoys they were protecting, with the ability to go faster from time to time in order to scout ahead, or to respond to a submarine threat. In this role they were quite successful.
Japan, which had not faced in World War I the kind of submarine threat that Britain and America had known, was much slower to appreciate the need for destroyer escorts. Indeed, after 1918 their destroyer development went in the opposite direction, producing some of the finest fleet destroyers by creating larger and more heavily-armed destroyers than anyone else. When the Pacific War began, these vessels were used with corresponding vigor, leading to the loss of many of these destroyers. Japanese naval construction emphasized replacement of the same types.
Since Japanese planners had hoped to knock the United States out of any potential conflict with the attack on Pearl Harbor, rather than to precipitate a long and grueling war, they had no contingencies in place to deal with attacks on merchant shipping. Moreover, American submarine commanders began to adopt German wolfpack tactics in harassing Japanese shipping. The Japanese only gradually embraced the notion of building destroyer escorts of their own. Only the Matsu class was built to defend merchant convoys, and with only 17 being completed by the war’s end, it was too little, too late. Still, it demonstrated some common characteristics with the Anglo-American destroyer escorts, in that it was much smaller (only 328 feet in length) with limited armament: three 5” guns, sixteen anti-aircraft gun emplacements, and torpedoes. Interestingly, the Matsu class lacked provision for depth charges, indicating that their escort duties emphasized protection against air attack, rather than submarine attack.
The destroyer escorts used by the British and American navies represented a war-winning design. Their abilities were well-attuned to the task of guarding convoys, and mass production permitted the construction of enough of these vessels to overcome the threats posed by submarines and air attack. The Japanese, in contrast, perceived the need for vessels of this type too late for them to play any meaningful role in the protection of Japan’s own endangered supply lines.
Sources:
Batchelor, John et al. The Complete Encyclopedia of Warships 1798 to the Present. Booksales, 2007
Bishop, Chris. The Encyclopedia of Weapons of World War II. Sterling, 2002
Parrish, Thomas. Simon and Schuster Encyclopedia of World War II. Simon and Schuster, 1978
Wheal, Elizabeth-Anne et al. A Dictionary of the Second World War. Bedrick, 1990
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