The Nazis terrorized the

1. Chapter 7: Leading the Grand Alliance The Nazis terrorized the A.T.L.A.N.T.I.C.

2. Chapter 7: Leading the Grand Alliance A. Allied ships sunk by U-boats • “U-boats” are German submarines (“unterseeboot” in German • Allied merchant ships were torpedoed at a rapid pace, threatening the survival of Great Britain

3. Chapter 7: Leading the Grand Alliance T. Terrible losses • In the course of the war, 36,000 were lost in the war on the Allied side • Allied lost 3,500 ships • By war’s end, the Allies will kill around 30,000 U-boat sailors

4. Chapter 7: Leading the Grand Alliance L. Liberty Ship • The Liberty ship was an American built cargo ship used to replace lost merchant ships • American naval shipyards could build these ships quickly • One Liberty ship was built in record time of four days and fifteen and a half hours • 2,751 Liberty ships built during World War II • They were 441 feet and carried 10,800 tons of supplies

5. Chapter 7: Leading the Grand Alliance A. American eastern seaboard hit • From February to May, 1942, 348 ships were sunk off the U.S. coast by German U-boats

6. Chapter 7: Leading the Grand Alliance N. Nazi “wolf-packs” • German Admiral Karl Donitz introduced the “wolf pack” strategy • One U-boat would follow a convoy and then radio a large group of U-boats to converge on and sink multiple ships

7. Chapter 7: Leading the Grand Alliance T. Tactic: “creeping attack” • British Captain F. J. “Johnnie” Walker used a new anti-submarine strategy known as “creeping attack” • While one ship located a sub with new “SONAR” technology, Walker, he crept up on it and dropped depth charges • Walker’s strategy was highly effective and he sank twenty U-boats on his own

8. Chapter 7: Leading the Grand Alliance I. Invention of SONAR • SONAR was an invention of the British (although they called it ASDIC) • SONAR (also known as radar) is short for “sound navigation and ranging” and allowed the Allies to find and track Nazi submarines • SONAR was a chief weapon used to counter U-boats in the Battle of the Atlantic

9. Chapter 7: Leading the Grand Alliance C. Convoy system • The convoy system was a counter U-boat strategy of grouping ships together for protection • Often merchants (or troop) ships were placed in the center with naval escorts (including friendly submarines) on the outside