USS Slater Header


Destroyer Escorts in the Atlantic

The Battle of the Atlantic was the longest battle of World War II. It began immediately upon the British declaration of war against Germany in September 1939 and ended with Germany's surrender to the Allies in May 1945. During those six years, thousands of ships were sunk and tens of thousands of men were killed in the Atlantic Ocean. The battle pitted Allied merchant and supply ships, along with their escorts, against German submarines, aircraft, and surface raiders. British Prime Minister Winston Churchill said of the Battle of the Atlantic, "everything elsewhere on land, sea and air, depended ultimately on the outcome of this battle." The outcome of the Battle of the Atlantic depended on the destroyer escort.

The outbreak of World War II caught both the British and German navies by surprise. Germany had less than fifty U-boats available in 1939, but the British had few escorts with which to counter them. The Nazis immediately began a program of unrestricted submarine warfare against British shipping, a strategy that came very near to starving England out of World War II. Although the British Navy began convoying ships as soon as the war started, its lack of escorts cost these convoys dearly. As more and more German submarines entered the battle, British shipping losses increased at an alarming rate.

Churchill appealed to President Franklin Roosevelt for aid. Although the United States was neutral, Roosevelt agreed to provide the British Navy with fifty obsolete four piper destroyers in exchange for the use of British bases in the Caribbean. The United States also began neutrality patrols, ostensibly to protect neutral shipping rights in the western Atlantic but also to give American naval commanders vital experience should the United States enter the war. The United States also agreed to build escort vessels for the British under the Lend Lease Program. It was this program, combined with America's experimentation with the World War I Eagle Boats, which ultimately led to the development of the destroyer escort.

The Japanese attack on Pearl Harbor on 7 December 1941 brought the United States openly into the war. Germany's declaration of war against the United States also greatly expanded the Battle of the Atlantic. German submarines, which had been operating out of western France since its capitulation in June 1940, had the range to reach the East Coast as well as the Gulf of Mexico. America's sudden entry into the war left it completely unprepared to face the U-boat menace. In the first months of 1942 alone, German submarines sank hundreds of Allied ships, mostly along the eastern United States.

Convoy Merchant Ships The United States Navy soon adopted the British convoy system, but it lacked enough ships to escort the hundreds of ships sailing across the Atlantic to supply England. By this time, the Navy had approved the destroyer escort design, but it would be nearly a year before the first destroyer escort joined the fleet. American industry was still transitioning from a peacetime to a wartime footing, so there not enough war materials necessary to build all of the warships and landing craft needed to fight a war in two oceans. Until the destroyer escorts were available in force, the US Navy was forced to rely on stopgap escort vessels, including the four pipers and sub chasers. Despite the mammoth efforts of these inadequate ships, 1942 proved to be the worst year of the war for the Allies in terms of ships lost in the Atlantic. Between January and December 1942, German U-boats and aircraft sank over 1,000 Allied ships both in the Atlantic and off the East Coast of the United States. 1

Finally, in January 1943, the first destroyer escorts entered the Battle of the Atlantic. American industrial capacity had caught up with demand and would soon exceed all expectations. By the end of the year, sixteen American shipyards were launching seventeen destroyer escorts per month. These new ships immediately began the dangerous task of escorting Allied merchant ships across the U-boat infested Atlantic. Destroyer escorts became even more deadly adversaries to the U-boats as improved electronic equipment, such as radar and HF/DF, became available. In addition, the construction of small escort carriers allowed the Navy to form hunter killer groups. These groups, consisting of one escort carrier supported by several destroyer escorts, were not tethered to a convoy, but could roam the Atlantic ferreting out U-boats and destroying them.

The tide of the Battle of the Atlantic turned irrevocably against the Nazis in May 1943. That was the first month that more U-boats were sunk than Allied merchant vessels. From May 1943 until the end of the war two years later, German submarines were unable to duplicate their successes of the first three years of the war. Destroyer escorts were an instrumental part of the Allied victory in the Atlantic. Their range and seaworthiness allowed them to escort convoys back and forth across the Atlantic despite fierce North Atlantic storms. Their radar, sonar and HF/DF equipment allowed them to detect U-boats, surfaced or submerged, by day or by night and in any weather conditions. Their speed, maneuverability and firepower made them lethal foes once a U-boat had been found. Finally, their overwhelming numbers due to their rapid construction made it virtually impossible for the submarines to hide.2

U-505 U Boat Destroyer escorts also carried out several important feats during the Battle of the Atlantic. Perhaps the most important of these feats was the capture of the German submarine U-505.3 The submarine was captured on 4 June 1944 by a hunter killer group composed of the escort carrier USS GUADALCANAL CVE60 and the destroyer escorts USS PILLSBURY DE133, USS POPE DE134, USS FLAHERTY DE135, USS CHATELAIN DE149, and USS JENKS DE665. The destroyer escorts attacked the submerged U-boat and forced her to surface. Boarding parties from the destroyer escorts then rushed over to the submarine while its crew abandoned ship. The American sailors stopped the submarine from sinking and then towed it back to Bermuda.

Enigma Royal Navy Museum The capture of the U-505 was one of the greatest intelligence coups of World War II. It gave the Allies a working Enigma code machine; a device which generated codes that the Allies had been only marginally successful at cracking. It also produced a complete set of the code books to go along with the machine. Most importantly, the U-505 gave the Allies the current settings for the Enigma machine in use by the U-boat fleet, which allowed the Allies to begin cracking German codes with great success. These finds allowed Allied cryptographers to intercept, decode and read German radio transmissions almost as quickly as the Germans themselves. The U-505 was an intelligence bonanza in other ways as well. It gave the Allies an opportunity to test the capabilities of their German foes, which in turn led to improved tactics to counter the U-boats.4

The USS SLATER also had a small part to play in the U-505 incident. Among the many discoveries on the submarine was a new type of acoustic torpedo. These deadly weapons locked onto the propeller noise of Allied ships and caused massive damage when they struck. The acoustic torpedo was taken from the U-505 and loaded onto the SLATER, which was in Bermuda at the time completing training exercises. The SLATER rushed the torpedo back to the United States for analysis, which resulted in an improved countermeasure to the acoustic torpedo known as the Foxer gear. This improved countermeasure saved many lives in the war's remaining months. The U-505 and the torpedo delivered by the SLATER are currently on display at the Museum of Science and Industry in Chicago, Illinois.

Germany's surrender in May 1945 ended the longest continuous battle of the war. Between 1939 and 1945, more than 2,700 Allied merchant ships were lost to enemy activity, with over 1,000 being lost to German U-boats alone. Over 130,000 Allied sailors lost their lives in the battle. Although these losses were severe, they would have been much worse without destroyer escorts. Once these ships entered the battle in 1943, U-boat successes dropped dramatically. By the time the SLATER joined the battle in 1944, convoy losses to U-boats had been almost eliminated. The SLATER escorted 176 merchant ships across the Atlantic without loss during World War II.5

As severe as the Allied losses were, they were much worse for the U-boat force. Of 1,100 German submarines produced during the war, nearly 800 were lost to Allied action. 28,000 of 40,000 U-boat sailors were killed in the Battle of Atlantic. Statistically, the job of a German submarine sailor was the deadliest of the entire war. Destroyer escorts were responsible for many of these U-boat losses. They were instrumental to the Allied success in Europe during World War II.6

Continue on to the next section by clicking here.

1  Numbers of ships destroyed in the Battle of the Atlantic vary by source. For comprehensive single-volume histories of the battle, see Morrison, Samuel Elliot, History of United States Naval Operations in World War II, Volume 1: The Battle of the Atlantic, September 1939-May 1943, Boston: Little, Brown and Company, 1956; Boyne, Walter, Clash of Titans: World War II at Sea, New York: Simon and Schuster, 1997.
2 See Gannon, Michael, Black May, New York: Harper Collins, 1998.
3 U-505 is now a National Historic Landmark on display at the Museum of Science and Industry in Chicago, Illinois.
4  For detailed accounts of the U-505’s capture, see Andrews, Tempest, 76-9, and Roscoe, Destroyer Operations, 309-10. For an in-depth record of the development of the Enigma and its importance to the Battle of the Atlantic, see Kahn, David, Seizing the Enigma: The Race to Break the German U-Boat Codes, 1939-1943, New York: Barnes and Noble Books, 1998.
5  Blair, Clay, Hitler’s U-Boat War: The Hunted, 1942-1945, New York: Random House, 1998.
6  In-depth accounts of the Allied victory in the Battle of the Atlantic are available in Morrison, Samuel Eliot, History of United States Naval Operations in World War II, Volume 10: The Atlantic Battle Won, Boston: Little, Brown and Company, 1956.

Back to top