World War II Questions of the Day Battle of the Atlantic Strategic Bombing

1. World War II Questions of the DayBattle of the AtlanticStrategic Bombing Daniel W. Blackmon IB HL History Coral Gables Sr. High

2. Essay of the Day • Choose TWO battles or campaigns from EITHER the First OR Second World War, and show how they affected the subsequent course and eventual outcome of the war. (1989) (HL)

3. Procedure • What happened? • What significant innovations occurred? • Why was the battle won or lost? • What consequences were there for the course of the war?

4. The Battle of the Atlantic • The Battle of the Atlantic was Hitler's second opportunity to defeat Great Britain, by strangulation rather than invasion.

5. The Battle of the Atlantic • Winston Churchill wrote that the U-boat menace was the only thing that really frightened him in the entire war. • Germany came perilously close to achieving strangulation of Great Britain.

6. The Battle of the Atlantic • The United States possessed in Great Britain an unsinkable aircraft carrier from which to attack Nazi-occupied Europe.

7. The Battle of the Atlantic • However, that attack could not be made until massive U.S. forces were delivered overseas. Control of what the U.S. Navy today calls Sea Lanes of Communication (SLOCS) is a strategic necessity.

8. The Battle of the Atlantic • The United States entered World War II on December 7, 1941, but D-day was not until June 6, 1944.

9. The Battle of the Atlantic • The delay is caused by the need to mobilize U.S. industrial power, mobilize and equip an enormous armed force engaged in two enormous theaters, deliver desperately needed supplies to our allies, and build up our bases.

10. The Battle of the Atlantic • .Shipping was the great bottle-neck. U.S. commitments were unprecedented in scope. Even our gargantuan capacity was strained.

11. Background • Great Britain, obviously, is an island, and a maritime power. • It possessed manufacturing capacity to produce weapons and even to ship a surplus to others.

12. Background • However, Britain's life-blood was sea-borne trade. Its great advantage, as a maritime empire able to draw upon the far flung resources of its world trading network, could be reversed and turned into a deadly disadvantage if the sea-borne life line were to be cut.

13. Background • Britain cannot feed itself. • It imported much of its non-ferrous metals and all of its oil.

14. Background • At the outbreak of war, Britain possessed the largest merchant fleet in the world, some 3,000 ocean-going merchant vessels and 1000 large coasters, comprising 21 million gross register tons.

15. Background • At the outbreak of war, the Germans only had 57 U-boats, only 27 of which were actually ocean-going. • U-boat construction had had a lower priority than other types in the pre-war build up because Hitler did not expect to fight a major war until 1943.

16. Background • Germany also possessed some disguised merchant raiders and a small fleet of warships--pocket battleships like the Graf Spee, cruisers such as Scharnhorst and Hipper, and the battleship Bismarck

17. Background • The fall of Norway and France drastically alters the strategic situation. U-boats can now be based at major ports such as Brest, St. Nazaire, Lorient, and La Rochelle, as well as in Norway.

18. Background • This gave them swift access to the crucial trade routes--meat from Argentina, wheat from the United States, oil from Nigeria, non-ferrous metal from South

19. Background • AfricaThey also provided bases for long-range German aircraft, such as the Focke-Wulf FW 200, which could take off in France and land in Norway.

20. Background • The Battle for the Atlantic begins in earnest with the Fall of France

21. German Strategy and Tactics • Admiral Karl Dönitz believed that with a force of 300 U-boats, he could strangle Great Britain. He achieved such a force by July 1942.

22. German Strategy and Tactics • The period from July 1942 to March 1943 was the most desperate phase of the Battle. The massacres of March 1943 not only nearly severed communications with Britain, but also led Dönitz to believe that they had won.

23. German Strategy and Tactics • Yet, in May 1943, Dönitz conceded defeat in his war diary. The margin of victory was narrow indeed.

24. German Strategy and Tactics • Prior to the war, Dönitz had described "wolf-pack tactics" against convoys.

25. German Strategy and Tactics • Convoys were not easily attacked by submerged U-boats, since the submerged speed was no better than the merchants'. • Therefore, if the U-boat were not in the proper location could not recover.

26. German Strategy and Tactics • "The way they operated was that, when the existence of a convoy had been approximately established, U-boat Command H.Q. ashore would warn the nearest U-boat group, which would send a submarine to find and shadow the convoy and 'home' the others onto it by wireless.

27. German Strategy and Tactics • “When they were assembled on the scene, they would launch night attacks on the surface, preferably up-wind of the convoy, and continue these for several nights. During daylight the U-boats would withdraw well clear of the convoy and its escort.

28. German Strategy and Tactics • “Attacking on the surface, they had an advantage in speed over most of the escorts." (Liddell Hart I 376)

29. German Strategy and Tactics • By far the best counter to these tactics was to locate the U-boat groups and route convoys to avoid them.

30. Stages of the Campaign • Following the Fall of France, the Germans concentrated on the Eastern Atlantic, especially the Cape route. • In April 1941, they extended operations into the central and western Atlantic.

31. Stages of the Campaign • After June 1941, when the British initiated convoys to Russia, the Germans extended operations into the Arctic regions, combining the U-boats with surface warships and air attacks.

32. Stages of the Campaign • The immediate aftermath of Pearl Harbor saw the Germans extend their front to the coastal United States. Our coastal traffic was not convoyed, and the U-boats massacred shipping within sight of our shores.

33. Stages of the Campaign • (My mother vividly remembers watching burning merchantmen from the beach at Jacksonville.)

34. Stages of the Campaign • May 1942 saw the beginning of U.S. coastal convoys as well as U.S. ship building moving into high gear.

35. Stages of the Campaign: The Crisis • There was no single reason for the crisis from July 1942 to May 1943. • Dönitz achieved his 300 ship fleet. • German cryptographers continued their success against the British naval code.

36. Stages of the Campaign:The Crisis • The Torch landings in North Africa diverted shipping and warships from the North Atlantic, the crucial theater. The campaign proved to require even more shipping and for a longer period than anticipated.

37. Stages of the Campaign:The Crisis • There was an interruption in Ultra decrypts in February 1942. (more on this later)

38. Stages of the Campaign:The Crisis • The RAF was not cooperating with the Royal Navy both in convoy patrols and attacks on submarine pens. Bomber Command rigidly persisted in attacking German cities ineffectually at great human cost.

39. The Turning Point • Factors which helped break the pattern included • Shipbuilding in excess of losses • Ultra decrypts of the naval code were restored in December, and convoys successfully re-routed

40. The Turning Point • Increase in the number of escorts. • Increased long-range Atlantic air patrols • Escort aircraft carriers with anti-submarine planes. • Improved radar, sonar, and depth charges.

41. The Turning Point • U-boat losses in May reached 43, or twice the replacement rate. • On May 24, Dönitz withdrew the U-boats from the Atlantic, writing "'We had lost the Battle of the Atlantic.'"

42. Cost of the Campaign • The Allies lost 2452 merchant ships of 13 million gross register tons. • The Allies lost 175 warships. • 32,000 British merchant seamen lost their lives.

43. Cost of the Campaign • The Germans lost 696 out of 830 U-boats. • The Germans suffered 25,870 killed and 5,000 captured out of 40,900 crewmen who sailed.

44. Cost of the Campaign • "This casualty rate--63 per cent overall--far exceeded that suffered by any other arm of service in the navy, army or air force of any combatant country."

45. Important Innovations: The Germans • The schnorkel device to recharge diesel engines • Atmosphere scrubbing equipment • (both developed too late to change the result of the campaign.)

46. Important Innovations: Allies • Huff Duff • Escort carriers and long range patrols • Liberty Ships • Decryption (Ultra)

47. Important Innovations: Allies • Huff Duff stood for High Frequency/Direction Finding, to locate shadowing U-boats. • The Allies built escort air craft carriers to give convoys their own air cover • Catalina and Sunderland flying boats provided long range patrols.

48. Liberty Ships • The U.S. shipbuilding program is simply without precedent in history. Fighting a war truly global in scope, we built a navy powerful beyond the wildest nightmares of our enemies while also building a mammoth merchant fleet.

49. Liberty Ships • The U.S. designed a standard tanker and merchant vessel, the famous Liberty ship. These were larger and faster than the pre-war norm.

50. Liberty Ships • Prefabricated sections were used. Average construction time was 3 months, with 3 being launched each day. One ship was built in 4 days 15 hours.