US NAVY DESTROYER ESCORTS OF WORLD WAR II MARK LARDAS ILLUSTRATED BY ADAM TOOBY AND IRENE CANO RODRÍGUEZ NEW VANGUARD 289 US NAVY DESTROYER ESCORTS OF WORLD WAR II MARK LARDAS ILLUSTRATED BY ADAM TOOBY AND IRENE CANO RODRÍGUEZ CONTENTS INTRODUCTION 4 DESIGN AND DEVELOPMENT 5 • Origins: The austere destroyer • Destroyer escort development • Construction OPERATIONAL HISTORY 16 • World War II: The Atlantic and European Theater • World War II: The Pacific War • World War II: Foreign service • Afterwards VARIANTS 31 • Fast attack transports • Radar pickets STATISTICS 40 • Evarts-class • Buckley-class • Cannon-class • Edsall-class • Rudderow • John C. Butler BIBLIOGRAPHY 47 INDEX 48 US NAVY DESTROYER ESCORTS OF WORLD WAR II INTRODUCTION As morning broke October 25, 1944, the 13 ships of “Taffy 3,” prepared for the day’s combat. The whimsically-named task unit comprised six slow escort carriers, and their seven-ship screen: three destroyers and four destroyer escorts. They were steaming in the Philippine Sea, a few miles off the island of Samar. The carriers, Casablanca-class “jeep carriers” which carried 24 aircraft and could reach 19 knots with a following wind, were expected to do the heavy work that day. Their aircraft were scheduled to provide ground support for the US troops ashore at Leyte, after the previous week’s landing. Their screen was there to protect them from attacking Japanese submarines The destroyers and destroyer and aircraft. Yet the dim light of dawn brought a surprise. To the north and escorts of Taffy 3 lay down east, coming from the San Bernardino Strait was the smoke of warships – smoke to protect the escort enemy warships. It was Japan’s Central Force: four battleships, including carriers, prior to making Yamato – the world’s largest – eight cruisers, and 11 destroyers. Having a torpedo attack on the battleships and cruisers of evaded detection, they were approaching gunnery range and could cruise the Japanese Central Force faster than the jeep carriers’ top speed. at the Battle of Samar. A Despite the disparity in force the screen did not hesitate. After laying a destroyer is in the foreground, smokescreen to hide the carriers, they threw themselves at the Japanese fleet, with a destroyer escort in the background, right. (USNHHC) buying time to allow the carriers to escape. Seven small warships, including four destroyer escorts carrying but two 5in guns and three torpedo tubes, charged the Japanese fleet. Over the next three hours, the US destroyers and destroyer escorts struck repeatedly at the Japanese. All four destroyer escorts launched torpedoes at the Japanese cruisers and battleships. One hit the cruiser Chokai. A second destroyer escort was credited with sinking a Japanese cruiser. Torpedoes expended, the destroyer escorts attacked with guns. 4 Two emptied their magazines firing. Finally, at 0920hrs the Japanese had The Black Swan-class sloop enough. Having sunk one escort carrier, two destroyers, and one destroyer Erne. The Black Swans were one escort for the loss of three Japanese heavy cruisers they broke off the battle. of several classes of ships rated as frigates or sloops built by the The destroyer escorts that fought so gallantly off Samar were ships the Royal Navy for antisubmarine US Navy really did not want, and ordered reluctantly. They were intended duty. They were comparable to fight submarines, but most arrived on the battlefield after the submarine in size and performance to US threat was tamed. They were largely manned by reserve officers and recruits destroyer escorts. (AC) just out of Navy boot camp. Most of the sailors manning these ships had never been to sea before. Yet throughout World War II they fought as they had fought off Samar, with magnificent courage, and a willingness to bring everything they had into battle. This is their story. DESIGN AND DEVELOPMENT The US Navy never wanted destroyer escorts. Mass-producing a second- class destroyer optimized for antisubmarine warfare was near the bottom of the Navy’s list of priorities. There were many reasons for the Navy to avoid building them and (to the Navy) few good reasons to order them. Despite the Navy’s effort to avoid the class of ships known as destroyer escorts, in the end it ordered over 1,000 of these ships, and built over 500. In many ways, the Navy’s worst fears about these ships were realized. By the time they arrived on the battlefield, the battle for which they were intended had already been won (largely by a different weapon, the antisubmarine aircraft). Despite their inadequacy for post-war needs, the surviving ships were too new to simply discard, and their existence blocked construction of appropriate replacements for over a decade. Yet while destroyer escorts were not the war-winning weapon their advocates claimed they would be, by the war’s end they proved useful and created a record for intrepid service equaled by few other warship types. Their crews set a standard for perseverance, improvisation, and determination rarely matched in naval history. Origins: The austere destroyer By 1939, the US Navy was evaluating its mobilization needs should war erupt. Prior to 1939 no nation, including Germany, believed the U-boat would be as big a threat to commerce as it had been in World War I. By January 1940, everyone began re-evaluating that conviction. Aircraft and 5 A cutaway showing the interior sonar at that point had not proved to be the antisubmarine nemesis they of a Rudderow-class destroyer were expected to have become. The United States, along with Great Britain, escort. Note the low bridge was examining new types of antisubmarine ships. Among the US Navy’s structure, steam propulsion considerations was that of the escort destroyer, a stripped-down destroyer plant, and 5in/38 gun turrets. These are the main differences optimized for antisubmarine warfare. This design would sacrifice size, speed, between this class of ship and and offensive armament to produce a warship capable of fighting submarines the earlier diesel-powered which could be built more quickly and more cheaply than a fleet destroyer. long-hull designs. The internal The fleet destroyers being designed and built in 1939 included the Fletcher arrangements were otherwise identical. (USNHHC) and Sumner-classes. These were 376ft long, displaced between 2,100 and 2,300 tons, and carried five or six 5in/38 dual-purpose guns, and ten torpedo tubes. They were designed for a speed of 36 to 37.5 knots. The previous Benson- and Gleaves-classes displaced around 1,650 tons, went 35–36 knots and had five 5in/38s and one or two quintuple-mount torpedo tubes. All carried depth charge racks, but only the Fletcher and Sumner had depth- charge launchers. Yet all were suited to antisubmarine duties. The desired escort destroyer would displace 1,200 tons, have a length around 300ft, a speed of 25 knots, and carry armament capable of sinking surfaced or submerged submarines. Adequate for convoy escort duties, these ships could substitute for fleet destroyers in a convoy’s screen, releasing destroyers for use in the battle fleet. Britain pursued this approach with their Black Swan-class sloops, Flower-class corvettes, and Hunt-class destroyers. None proved completely satisfactory. The corvettes were slow and lightly armed. The Hunts had insufficient range for open-ocean service. In 1939 the Navy’s General Board was unenthusiastic about an austere destroyer. The Navy never had enough fleet destroyers. They viewed an austere design, an escort destroyer, as a trap. Resources going into escort destroyer production would come from fleet destroyer construction. The US was still at peace. Why not build more fleet destroyers instead of filling building slips with keels for less capable ships? Building small fleet destroyers similar to the 1,500-ton Farragut-class or perhaps building more Gleaves-class ships with improved antisubmarine capability was considered. This was discarded after the Navy realized off-the- shelf steam engines were too large for Farragut hulls, and would need to be specially ordered, negating any savings in resources. The Navy deferred the decision to make escort destroyers, whether of austere or small fleet designs, concentrating on increasing production of new designs. Over the next two years, the Navy considered several proposals to build small destroyers – between 750 and 1,200 tons – with a battery of 5in dual-purpose guns and 6 capable of anywhere from 25 to 35 knots. These included internal naval designs and unsolicited designs submitted by William Francis Gibbs, chief naval architect for Gibbs and Cox. Including two designs offered by Gibbs, the Navy considered six different austere destroyer designs between August 1940 and February 1941. None of these designs went beyond the planning stage. They could not be built, lacked the range for ocean service, or cost almost as much as a fleet destroyer. Building an austere destroyer for escort duties was estimated to cost $6.8 million to an estimated $8.1 million for a repeat Gleaves. The conventional fleet destroyer appeared to be the best bargain. Yet the Navy kept looking at escort destroyer designs. In February 1941, the General Board called for yet another simplified destroyer. This A stylized diagram from a one was to have a speed of 22 to 24 knots, with a waterline length of 280ft. It US Navy sonar manual showing would have a 12,000 shaft horsepower (shp) engine, and mount two single- the layout of the sonar system aboard a destroyer escort. The purpose (surface only) guns, either the old 5in/51 caliber or 4in/50 caliber. listening equipment, including Endurance would be 6,000nmi at 12 knots, a speed which allowed the design a retracting dome containing to escort fast convoys across the Atlantic. The ships would have one triple the sonar gear, was in the bow torpedo tube mount. For anti-aircraft protection, it would have one quad while the sonar room, where sound information collected 40mm Bofors aft and two single 20mm amidships. The design was modified. was interpreted, was in the More antiaircraft capability was desired. Two 5in/38 or three 3in/50 dual- superstructure near the bridge purpose guns replaced the original main battery. Light antiaircraft batteries and combat information were increased, adding more 20mm guns. This design, which displaced 1,225 center. (AC) tons, became the basis of the World War II destroyer escort. In May 1941, the Navy ordered 50 of these ships, and then almost immediately cancelled the order. The fleet destroyer was still viewed to be better value. The Navy worried space in Navy building yards used to construct destroyer escorts would then be unavailable for fleet destroyer construction. In July, the General Board and Chief of Naval Operations (CNO) recommended no destroyer escorts be built. The Navy, still at peace, preferred increasing its conventional destroyer numbers. The stalemate was broken by Britain. In June 1941, they asked for 100 escort destroyers. They requested a ship with the characteristics of the just-cancelled destroyer escort design. The submission was a Lend-Lease request. Britain would “borrow” the ships from the US Navy for the duration of the war, and then return them. It would only pay for ships retained by the Royal Navy. (Effectively, this would be ships sunk, which could not be returned.) Since the US Navy lacked ships of this type to lend Britain, it had to build them first. Roosevelt authorized construction of 50 destroyer escorts in US shipyards for Britain in August 1941. 7 Twin rudders were added late in the design of the destroyer escort. The change permitted greater maneuverability as the tight-turning circle achieved in this picture demonstrates. The photograph was taken during the acceptance trials of USS Buckley, the lead ship of its class. (USNHHC) These new ships became Evarts-class destroyer escorts in the US Navy and one of two types of “Captain”-class frigates in the Royal Navy. (Initially these ships were named for Royal Navy captains who served under Horatio Nelson. Later names expanded to include other Napoleonic-era Royal Navy captains.) Contracts were signed in November 1941, and construction The hedgehog changed started in February 1942. These ships were all built in naval shipyards. The antisubmarine warfare. The projectiles sank faster than design was modified from the Navy’s order. The ship was given an open- depth charges, allowing topped bridge, above the pilot house. The sonar shack (or Asdic hut) was less time for a submarine to below the bridge beside the pilot house. The torpedo tubes were removed. To maneuver to escape. Since avoid bottlenecks caused by the limited availability of reduction gearing, and they were fired ahead of the destroyer escort, sonar contact to avoid competition for scarce steam turbines, the ships used a diesel-electric could be maintained until they drive. Electric motors powered by diesel engines turned the propellers. were dropped. World War II Unfortunately, diesels also proved to be in short supply. Instead of using destroyer escorts mounted the eight 1,500hp General Motors diesels, these ships carried four. This resulted hedgehog launcher in a fixed box aft of the forward gun. (AP) in a drop in top speed to 21 knots. Destroyer escort development Destroyer escorts were submarine killers. Their antisubmarine armament included two depth-charge racks aft and eight K-gun depth-charge launchers (four on British ships), plus a hedgehog fitted aft of the Number 1 gun. The hedgehog launched 24 100-pound projectiles, which exploded on impact with a submarine. Fired ahead of the ship, it allowed sonar contact to be maintained throughout the attack. The projectiles sank three times faster than depth charges, in a circular pattern. Fired accurately, at least two of the projectiles would hit the submarine, sinking it. It was a deadly weapon. 8 The Evarts mounted three 3in/50s. These could serve both anti-ship and anti-aircraft duties. While the 3in gun was light against all but the smallest surface warships, a hit from one could destroy a surfaced submarine. The light antiaircraft battery was also beefed up. Due to shortages in Bofors 40mm guns, the as-built design had a quad 1.1in (Chicago Piano) aft, instead of a twin 40mm, although the British substituted a twin 40mm for the 1.1in. Twin 40mms later replaced the 1.1s on US ships, as well. Nine single-mount 20mm were added. The Royal Navy also added 2-pdr pom-poms to ships operating in the North Sea and English Channel. These were intended for use against E-boats, and explosive motor boats. Destroyer escorts were not equipped with the sophisticated central fire The first four classes of control systems carried on destroyers. This reduced performance against destroyer escorts were armed fast moving surface ships or aircraft. They were incapable of accurately with 3in/50 caliber main guns. Although on the light hitting surface targets while maneuvering at high speeds. This was not seen side, it could sink a surfaced as a serious handicap as destroyer escorts were intended for use against submarine and provide submarines, while fleet destroyers were intended to fight surface warships. antiaircraft protection. (AC) For improved antiaircraft performance, destroyer escort antiaircraft guns were equipped with Mark 14 lead-computing gunsights, while the 3in/50 main guns were fitted with the Mark 52 gunsight. The Evarts-class set the standard for World War II destroyer escorts. All subsequent US-built destroyer escorts were developments of the Evarts. They were unique in being built without torpedo tubes. While initially done to conform to British desires, subsequent Evarts for US service left them off due to a combination of the short hull and a lack of available triple mounts. While the Evarts were built for Britain, most ended up commissioned as US warships. Between the signing of the first construction contracts in November, 1941 and the first keel-laying for one of these ships in February 1942, the United States’ belligerent status changed. On December 7, 1941, Imperial Japan attacked the United States at Pearl Harbor, and three days later Germany and Italy declared war on the United States. Suddenly the United States was at war and its need for escort ships acute. Over the next year, the choice was no longer between fleet destroyers and escort destroyers, the need was for any warship, and there was an acute shortage of escort warships. In January 1941, the Navy ordered another 250 destroyer escorts. All 300 ordered ships were to be identical, and could go to either the US Navy or the Royal Navy. Another 420 destroyer escorts were ordered in September, 80 more soon after, and a final 205 ordered in May, 1943. In all, contracts were let to build 1,005 destroyer escorts. Even ignoring potential improvements, the number of destroyer escorts to be built doomed the concept of identical ships. Despite the critical need for antisubmarine warships, insufficient numbers of the GM diesel engines 9 were available, even after the number of engines required was halved from eight to four. The solution was finding a substitute engine. General Electric had 6,750hp steam turbines available. Two of these could provide the 12,000hp originally intended for destroyer escorts, restoring the ship to a 24-knot top speed. But the Evarts’, hull was too short to fit the engines. Lengthening the hull to 300ft at the waterline provided the extra room needed. The extra length allowed installation of a triple torpedo tube while retaining the extra midship antiaircraft Due to a shortage of 40mm guns carried by the Evarts. The result was the Buckley-class, the first “long- Bofors, most early destroyer hull” destroyer escort class. Moreover, the longer hull reduced wave-making escorts carried a quad 1.1in resistance as much as it increased resistance due to greater wetted surface. antiaircraft gun in the aft That meant the extra length and displacement gained by lengthening the hull position. As the twin 40mm became available, they came with no performance penalty. All subsequent destroyer-escort classes replaced the 1.1ins. Still later, were long-hull designs. a quad 40mm was installed Nor did the Buckleys use geared turbines. The turbines powered dynamos in many destroyer escorts. which powered the electric motors turning the ship’s two propellers. As a result, This picture shows a quad 1.1in (foreground) and a quad these ships became known as turbine-electric, or TE destroyer escorts. The 40mm at a training school for Evarts were classified as GMT (for General Motors Tandem diesels) vessels. destroyer escort crews. (AP) Two other destroyer escort classes were also added, the Cannon- and Edsall-classes. Both used the Buckley hull, with diesel engines instead of Buckley’s turbines. They were also armed with the same suite of weapons as Buckleys, including the triple torpedo mount. However, since they had half the horsepower of the Buckleys, they had a top speed of just 21 knots. The Cannons were outfitted with the same General Motors 16-278A diesels used by the Evarts. It made more sense to discontinue short-hull construction, while using the same engines in a more capable longer hull. These were termed Diesel Electric Tandem (DET) destroyer escorts. The Edsalls substituted four 1,500hp Fairbanks-Morse geared diesels for the GM diesel-electrics of the Cannon class. Although the Cannon-class was developed first, the first Edsall-class ship was laid down in July 1942 while the namesake Cannon was laid down in November. Availability of diesels remained the major constraint for both classes. Landing craft and submarines used the same diesels as these ships, competing with destroyer escorts for them. The US Navy preferred arming destroyer escorts with a main battery of 5in/38 rather than the 3in/50s of the first four destroyer escort classes. As with the absence of torpedoes on the Evarts and the 1.1in quads on early construction Evarts and Buckleys, the main gun decision was driven by availability. The 5in/38 was the Navy’s standard heavy antiaircraft gun. Fleet 10