Lesson 22 WW II -- Second Battle of the Atlantic, Pt. 1

Lesson Objectives Understand the magnitude and significance of the Battle of the Atlantic during World War II. Understand the degree of British dependence on maritime lines of communication. Describe U.S. participation in the Battle of the Atlantic prior to December Describe and analyze the tactics and technology used by both sides in the Battle of the Atlantic. Understand the importance of code breaking in the Atlantic war.

"The only thing that ever really frightened me during the war was the U-boat peril." Winston S. Churchill, The Second World War, Volume II, Their Finest Hour 1949

The Battle of the Atlantic Begins ( 0:43 – 8:00 )

The U-boat Threat Admiral Karl Dönitz ( ) German Submarine Commander Hitler told the Kriegsmarine that the war would not begin until 1945 The Kriegsmarine built Plan Z, their expansion blueprint, on this target 249 U-boats by 1944 (January 1939)

The U-boat Threat Type VIIC U-boat Range: 8,500 nm Crew: 44-52Torpedo load: 14 Germany had 57 operational U-boats in September 1939 Only about half of these were effective ocean-going units

Source: The World At War

Allied Strategy in Battle of the Atlantic Protect existing shipping Build to replace shipping losses, expand fleet Go on the offensive against the U-boats

Allied Strategy in Battle of the Atlantic Protect existing shipping Build to replace shipping losses, expand fleet Go on the offensive against the U-boats

Allied Strategy in Battle of the Atlantic Protect existing shipping Employ convoy system immediately Increase escort capability

Convoy System RN employed convoys from start Did not have enough escorts Started crash construction program USN did not use convoys initially Second “Happy Time” * for Germans * Jan-Aug 1942

Convoy System Introduction of Aircraft … turned the tide More escorts Hunter-Killer tactics (later)

Escort Vessels Royal Navy hard pressed in all theaters of operation Not enough destroyers (standard convoy escort)

Escort Vessels Royal Navy hard pressed in all theaters of operation Not enough destroyers (standard escort) Needed more esports to protect convoys everywhere

Flower-class Corvettes Length: 205 feet Displacement: 940 tons Speed: 16 knots 394 built (UK, Canada) Corvette: Escort warship, smaller than destroyer Original Royal Navy design adopted from whale catcher ship Not ideal:slow, uncomfortable in rough seas but … Could be produced in small shipyards

Flower-class Corvettes ( 7:06 )

Escort Vessels Royal Navy hard pressed in all theaters of operation Not enough destroyers (standard escort) Needed more escorts to protect convoys everywhere still ∧

U.S. Becomes Involved

Remember this one? History doesn’t repeat itself, but it rhymes. Attributed to Samuel Clements ( )

Unrestricted Submarine Warfare August 17, 1940 Hitler Declares Unrestricted Blockade Around British Isles America Gets Involved September 2, 1940 Destroyers For Bases Agreement February 1, 1917 April 6, 1917 Germany resumes unrestricted sub warfare U.S. declares war on Germany … again! Why did FDR not ask for declaration of war? Freedom of the Seas: Fundamental Principle of U.S. Foreign Policy What drove this?

WW II – America on the Sidelines American political & economic actions before Pearl Harbor attack or

Other Threats FW 200 Condor Maritime Patrol Aircraft Source

Catapult Armed Merchantmen Source HAWKER “HURRICAT”

Catapult Armed Merchantman (CAM) ( 16:25 – 18:25 )

Catapult Armed Merchantmen Source Operational History 35 CAM ships converted Made 175 voyages, were lost to enemy action (34%) Eight operational catapult launchings Six enemy aircraft shot down One RN pilot lost HMS Ariguani

Other Threats Surface Raiders Pocket Battleships / Heavy Cruisers Example: Admiral Graf Spee Auxiliary Cruisers Example: Atlantis

Surface Raiders Pocket Battleships & Heavy Cruisers Admiral Graf Spee Six 11-inch guns Eight 5.9-inch guns Speed: 21 knots Displacement: 16,200 tons Scuttled, December 17, 1939 Off Montevideo, Uruguay After battle with thee British cruisers War Cruise August-December 1939 Sank 9 merchant ships (50,000 tons) Video

Surface Raiders Auxiliary Cruisers Auxiliary Cruiser Atlantis Atlantis with dummy funnel Armament Layout Hidden torpedo tubes & guns

Surface Raiders Auxiliary Cruisers Auxiliary Cruiser Atlantis Atlantis with dummy funnel First auxiliary cruiser to sink a merchant ship Highest tonnage sunk of all surface raiders Circumnavigated the globe 22 ships, 146,000 tons

Lesson 22 WW II -- Second Battle of the Atlantic, Pt 2 Next:

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