Hitler’s U-Boat War- The Hunted 1942-45 Read online

  Once again, to Joan—my wife,

  best friend, and loyal and

  patient collaborator

  Contents

  Cover

  Dedication

  Title Page

  Foreword

  List of Maps

  List of Plates

  The U-Boat Campaign Against the British Commonwealth and the United States

  One

  Two

  Three

  Four

  Five

  Six

  Seven

  Eight

  Nine

  Appendices

  Appendix 1: Oceangoing U-boats Assigned to Combat: The Final Years: September 1942-April 1945

  Appendix 2: U-boat Patrols to the North Atlantic: September 1942-April 1945

  Appendix 3: Allied Cargo Convoy Sailings on the North Atlantic Run in the “Critical Period”: September 1942-May 1943.

  Appendix 4: U-boat Patrols to the South Atlantic and Indian Ocean: September 1942-April 1945

  Appendix 5: U-boat Patrols to the Americas: September 1942-April 1945

  Appendix 6: U-boats Assigned to the Arctic Area: September 1942-April 1945

  Appendix 7: U-boats Transferred to the Mediterranean Sea: September 1942-April 1944

  Appendix 8: Huff Duff

  Appendix 9: Principal North Atlantic Cargo Convoys Inbound to the British Isles September 1, 1942-December 3 1, 1944

  Appendix 10: Allied Aircraft Deployed in ASW Roles in the North Atlantic Area (by Squadron, September-October 1942

  Appendix 11: The Long- and Very-long-range Allied ASW Aircraft Situation in the North Atlantic (by Types and Squadrons, March 1943)

  Appendix 12: Atlantic Force U-boats That Aborted Patrols: January-June 1943

  Appendix 13: Allied Heavy Bomber Raids on U-boat Facilities: 1943-1944

  Appendix 14: American Destroyer Escort (DE) Production: January I-July 1, 1943

  Appendix 15: Special Oil and Troopship Convoys for Torch and the British Isles: 1943-1944

  Appendix 16: The Top Twenty U-boat Skippers: 1939-1945

  Appendix 17: The Top Renty U-boats: 1939-1945

  Appendix 18: U-boats Scuttled or Dismantled at War's End

  Appendix 19: U-boats Surrendered at War's End

  Appendix 20: Allied and Neutral Ships and Tonnage Sunk by Cierman and Italian Submarines in World War 11: September I, 1942-May 8, 1945

  Acknowledgments and Sources

  Afterword

  Index

  Books By The Same Author

  Copyright

  FOREWORD

  In Volume I of this history, The Hunters, I described, analyzed, and assessed in great detail the first three years of the German U-boat war: August 1939 to August 1942. This volume, The Hunted, is a continuation of the U-boat story from September 1942 to the surrender of Germany in May 1945.

  Like the U-boat war itself, Volume I was subdivided into two sequential books: the U-boat war against the British Empire (1939-1941) and the U-boat war against the Americas (December 1941-August 1942). This second volume contains but one book: the U-boat war against the naval forces of the British Commonwealth, including notably Canada, and those of the United States.

  Adolf Hitler’s Third Reich was absurdly unprepared for a naval war with the Allies. Therefore, for the second time in the twentieth century, German navalists were compelled to resort to cheap, mass-produced submarines, manned mostly by civilian volunteers, to conduct the war at sea, often and somewhat misleadingly called the “Battle of the Atlantic.” They conceived and waged a guerre de course, or war against British-controlled merchant shipping, designed to blockade the British Isles so tightly that the starved-out British government would be forced to lay down arms and withdraw from the war.

  The commander in chief of the U-boat force, Karl Dönitz, characterized this German naval strategy as a “tonnage war.” The objective was the destruction of British-controlled merchant ships wherever they could be found with the least risk to the U-boats. It did not matter whether the ships were large, medium, or small, laden or empty, close to or distant from the battlefronts. The goal was to sink merchant ships (tonnage) at a rate much faster than the British could replace them with new ships, thereby whittling down the existing tonnage to a decisively unworkable level.

  As described in Volume I, this “tonnage war” against the British-controlled merchant fleet failed in the period from 1939 to 1941 for various reasons. There were not enough U-boats to bring it off and those deployed to the battlefronts had so many shortcomings that they were not suitable for the task. They sank 1,125 ships for about 5.3 million tons, but the British Commonwealth more than made good these losses by new construction and by acquisition of shipping from the United States, German-occupied nations such as Norway, France, Belgium, the Netherlands, and Greece, and by captures of Axis-controlled vessels. At the end of 1941, the British-controlled merchant fleet, including tankers, was larger by about three million tons than it was in 1939.

  After the United States formally entered the war against the Axis powers in December 1941, Dönitz viewed the British and American merchant-marine fleets as a single entity and continued the “tonnage war” as before. Sensing an opportunity to strike a heavy blow at low risk, he threw the main weight of the U-boat force at the Americas for about eight months, from December 1941 to August 1942. That campaign destroyed about six hundred Allied ships for about three million tons, but by that time American shipyards, employing tens of thousands of women, were mass-producing “Liberty ships,” tankers, and other types at a prodigious rate, not only making good all Allied merchant-ship losses but also swelling the size of the combined Allied fleet to undreamed of tonnage levels.

  As in World War I, strategists at the British Admiralty and senior fleet commanders of the Royal Navy were slow to recognize and to properly come to grips with the U-boat threat. They believed that by convoying and by arming merchant ships with 4” or larger guns, and employing secret asdic (sonar) technology, which was developed between the wars, any U-boat force the Germans deployed could be neutralized and quickly defeated. This smugness did not last for long. It turned out that the besieged Royal Navy, committed to an overabundance of tasks, had nowhere near enough blue-water escorts to properly protect convoys and, furthermore, the smallish Hunt-class destroyer escort, specifically designed for that purpose and rushed into production, failed to live up to its promise and could not be employed on the vital North Atlantic run between the Americas and the British Isles.

  Hard-pressed on land and sea and in the air, the British chose brains over brawn. To counter the Luftwaffe, British scientists perfected a radar-warning net, then miniaturized radar to fit into aircraft, sharing this ingenious, war-decisive technology with Canada and the United States. At the same time, other British intellectuals, capitalizing on technical help from the defeated Poles, broke into the German Enigma military encoding-machine system. Still other British scientists and engineers developed an astonishingly accurate land-based high-frequency direction-finding network (Huff Duff), then miniaturized the devices to fit on ships. Radar, codebreaking, and to a limited extent Huff Duff,* and other scientific breakthroughs, enabled the Royal Navy and Royal Air Force to thwart “wolf pack” attacks by the Atlantic-based U-boats on convoys in 1941, in large part, by simply routing convoys around known U-boat positions.

  That same year, 1941, the United States gradually—and illegally—entered the “Battle of the Atlantic.” Having already loaned the British sixty warships for convoy escort (fifty old destroyers and ten Coast Guard cutters), the United States occupied the Avalon Peninsula of Newfoundland and built a naval base at Arge
ntia. It then occupied Greenland and Iceland and built substantial naval and air bases on Iceland. It commenced building a naval base in Londonderry, Northern Ireland, and slated about fifty more destroyers to escort fast convoys on the North Atlantic run between Canada and Iceland and the reverse. The passage of the Lend-Lease Act enabled America to build warships (“jeep” carriers, destroyer escorts, and frigates, among other types) and Liberty-type merchant ships for Britain and Canada and to repair warships of those nations in American naval shipyards. A relaxation of the Neutrality Act authorized American merchant ships to enter the war zones in Europe to deliver Lend-Lease war matériel and oil.

  When the United States formally entered the war in December 1941, President Roosevelt and his military chiefs, adhering to prior secret agreements, revalidated a war policy of defeating Germany and Italy first, then Japan. Notwithstanding the losses incurred in the Japanese attack on Pearl Harbor and other places in the Pacific and Far East, the United States retained substantial naval forces in the Atlantic Ocean area to combat the U-boats, to insure that the vital North Atlantic cargo run to the British Isles and the Arctic cargo route to northern Russia continued to operate effectively, and to transport tens of thousands of troops to Iceland, Northern Ireland, and the British Isles. Owing to its prior gift of sixty warships to the Canadian and British navies, the United States did not have enough escorts to initiate convoying in the waters of the East Coast, Gulf of Mexico, and the Caribbean Sea in the first four months of 1942, during which time the Allies incurred grievous merchant-ship and crew losses to U-boats.

  By the end of August 1942, when Volume I of this history, The Hunters, concludes, the U-boats in three years of naval warfare had sunk in all waters about two thousand Allied ships of all sizes, shapes, and types, for about 9.3 million gross tons. While these figures are quite impressive—indisputably a notable chapter in the history of naval warfare—they were not anywhere near enough. New merchant-ship production in American yards alone had reached a level of about six million gross tons a year and was rising dramatically; the Commonwealth turned out another million-plus gross tons of new shipping and repaired a great number of ships that had been laid up with damage.

  Moreover, by August 1942, the Allies, in a reverse tonnage war, had in hand sufficient naval and air assets not only to defend convoys but also to kill U-boats faster than the Germans could replace them or produce meaningful numbers of radically improved models. Those assets included growing numbers of antisubmarine warfare (ASW) aircraft and experienced convoy surface-ship escorts (destroyers, destroyer escorts, corvettes, catapult merchant ships, and with merchant aircraft carriers and “jeep” carriers in the offing), centimetric-wavelength (microwave) radar, land-based and shipboard Huff Duff, forward-firing Hedgehog antisubmarine bombs, improved conventional shipboard and air-dropped depth charges with Torpex warheads, and a large number of experts on both sides of the Atlantic working to break back into German naval Enigma.

  Nevertheless, in the remaining years of the war, from August 1942 to May 1945, the U-boat force sank about one thousand more Allied ships for about 5.7 million gross tons. Most of those sinkings (seven hundred ships for about four million gross tons) were achieved in the nine months from September 1942 to June 1943, a result comparable to the eight-month onslaught in the Americas from January to August 1942. These new sinkings brought the final toll of the German tonnage war to about three thousand ships of all types for about fourteen million gross tons.*

  What lies ahead in these pages are further accounts of intense and exhausting battles between convoys and “wolf packs”—few days in the North Atlantic were ever easy—and the story of how the Allied navies learned that electronic intelligence combined with aircraft was the most effective anti-U-boat weapon system, how those navies finally acquired the correct aircraft to do the job, and how the Germans sought desperately to produce radically new submarines to counteract these Allied technical advances—and failed.

  As the term implies, a “tonnage war” is by its very nature a naval war entailing an analysis of many statistics. Only a very few historians and readers welcome the intrusion of statistics, and partly as a result, this aspect of the U-boat war has been egregiously neglected. This neglect, in turn, has led to serious distortions in the perception of the results of the U-boat war. Although I have sought to include as few statistics as possible, this account is the first attempt by anyone to prove by statistical analysis that, contrary to the accepted wisdom—and mythology—at no time did the German U-boat force ever come close to winning the “Battle of the Atlantic,” bringing on the collapse of Great Britain and, in such case, a different shape and outcome of the war in Europe.

  I did not set out beforehand to prove this revolutionary conclusion. It became obvious along the way. I was at first startled and skeptical, even disbelieving. I invested years of study, analysis, and writing before I became fully convinced of these findings and was willing to present them to the community of naval historians and to the public.

  CLAY BLAIR

  Washington, D.C., London, Hamburg,

  and Washington Island, Wisconsin,

  1987–98

  LIST OF MAPS

  The British Isles and Northern Germany

  North Atlantic Convoy Routes

  The Arctic

  Bay of Biscay

  The Mediterranean

  Gulf of Mexico and the Caribbean

  United States East Coast

  LIST OF PLATES

  Cutaway illustrations of Type VIIC and Type IXC U-boats appear on pages xxx and xxxi.

  1. Deployment of U-boats by Battlefront: September 1 to December 31, 1942

  2. Most Productive U-boat Patrols to American Waters (by confirmed gross tonnage sunk over 40,000 in 1942)

  3. U-boat Successes in South African Waters: October-November 1942

  4. Losses of Troopships and Other Large Non-tanker British-Controlled Vessels: September-December 1942

  5. North and Middle Atlantic Convoy Routes Reaffirmed at the Atlantic Convoy Conference: March 1 to March 12, 1943

  6. Results of RAF Coastal Command’s Bay of Biscay Offensives (Derange, Musketry, Seaslug, and Percussion) by 19 Group: April 10-September 21, 1943

  7. German U-tanker Aborts, Losses, and Damage: May-August 1943 ..,”

  8. U-boats Commissioned in 1944 (by Type per Month)

  9. Type VII U-boats in French Bases: June 4, 1944

  10. Allied Bomber Raids on Electro Boat Assembly Yards in Hamburg, Bremen, and Kiel: December 31, 1944-April 14, 1945

  11. Summary of North Atlantic Convoy Arrivals: 1942-1945

  12. Summary of Middle Atlantic Convoy Arrivals: 1942-1945

  13. Allied Convoys That Lost Six or More Ships: January 1942-May 1945

  BOOK THREE

  THE U-BOAT

  CAMPAIGN AGAINST

  THE BRITISH

  COMMONWEALTH

  AND THE

  UNITED STATES

  SEPTEMBER 1942-MAY 1945

  ONE

  OVERVIEWS

  At the beginning of the fourth year of World War II, September 3, 1942, Allied and Axis leaders were preoccupied with the following major military operations:

  • STALINGRAD AND THE CAUCASUS. Still dominating all else, the massive German armies and air forces in the southern regions of the Soviet Union had advanced steadily over the summer. Owing to the great symbolic importance of Stalingrad, Hitler insisted on its capture. Toward that end he diverted forces from the Caucasus Mountain area, thus slowing the German drive toward the Soviet oil fields to a crawl.

  When Hitler’s intentions became clear, Stalin and his generals rushed reinforcements to Stalingrad, setting the stage for one of the greatest battles of the war. As German forces closed on the city in early September, Stalin’s chief military commander, Georgi Zhukov, saw an opportunity developing for a counterattack and obtained permission from Stalin to strike in early November.

  • ALLIED AID TO THE SOVIET UNION. Sti
ll doubtful that the Soviet armies could hold out alone, President Roosevelt insisted that Washington and London do everything possible to provide Moscow with assistance. Chief among the measures agreed to were a renewal of PQ convoys to Murmansk in September, a diversion of American fighters and bombers to the southern regions of the Soviet Union, and upgrades of port facilities in the Persian Gulf area and the railroad running through Iran to the Soviet Union.

  • NORTH AFRICA. At the end of August, Erwin Rommel attempted to break deeper into Egypt through British lines at Alam Haifa, but he failed. Dispirited and ill, he requested relief. On September 22, Georg Stumme, a tank specialist from the German campaign in the Soviet Union, replaced Rommel, who hospitalized himself in Germany. Meanwhile, the new British commanders, Harold Alexander and Bernard Montgomery, prepared the growing British Eighth Army (powerfully supplied with American tanks and aircraft) for an attack out of Egypt to the west designed to destroy the Axis forces, in particular Germany’s shrinking and exhausted Afrika Korps.

  • TORCH. Preparations for Torch, the Allied invasion of French Northwest Africa, which had supplanted Sledgehammer, the first planned invasion of France, as a “second front” in 1942, proceeded apace. Commanded by Dwight D. Eisenhower, Torch forces were to land at three places: the Atlantic coast of Morocco and inside the Mediterranean at Algiers and Oran.

  Torch was a risky undertaking. Some of the chief dangers:

  1. Should the secret leak, the Germans might pre-position as many as fifty to one hundred U-boats west of Gibraltar to repel the Allied invasion forces.

  2. The Germans might occupy Vichy France and Spain, capture Gibraltar, seize the neutralized French fleet at Toulon, and trap Allied forces inside the western Mediterranean.

  3. The shy Italian surface fleet, supported by the Italian Air Force, the Luftwaffe, and Italian submarines, might finally mount an aggressive attack against Allied naval forces in the Mediterranean.