Download 22: WW II : Second Battle of the Atlantic

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 1941.
• 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
Hitler told the Kriegsmarine that the war would
(January 1939)
not begin until 1945
The Kriegsmarine built Plan Z, their expansion
blueprint, on this target
• 249 U-boats by 1944
Admiral Karl Dönitz (1891-1980)
German Submarine Commander
The U-boat Threat
Germany had 57 operational U-boats in September 1939
• Only about half of these were effective ocean-going units
Type VIIC U-boat
Range: 8,500 nm
Crew: 44-52
Torpedo load: 14
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
• More escorts
• Hunter-Killer tactics (later)
… turned the tide
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
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
Length: 205 feet
Displacement: 940 tons
Speed: 16 knots
394 built (UK, Canada)
Flower-class Corvettes
( 7:06 )
Escort Vessels
Royal Navy hard pressed in all theaters of operation
Not enough destroyers (standard escort)
still
Needed more escorts to protect convoys everywhere
∧
U.S. Becomes Involved
Remember this one?
History doesn’t repeat itself, but it rhymes.
Attributed to Samuel Clements (1835-1910)
Unrestricted
America Gets
Submarine
InvolvedWarfare
… again!
February 1, 1917
Germany resumes unrestricted sub warfare
April 6, 1917
U.S. declares war on Germany
Freedom
the Seas:
Hitler Declares Unrestricted Blockade
August 17,of1940
What
drove
Around
British this?
Isles
Fundamental Principle of U.S. Foreign Policy
September 2, 1940
Destroyers For Bases Agreement
Why did FDR not ask for declaration of war?
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
HAWKER “HURRICAT”
Source
Source
Catapult Armed Merchantman (CAM)
( 16:25 – 18:25 )
Catapult Armed Merchantmen
Operational History
HMS Ariguani
35 CAM ships converted
• Made 175 voyages, 1941-1943
• 12 were lost to enemy action (34%)
Eight operational catapult launchings
Six enemy aircraft shot down
One RN pilot lost
Source
Other Threats
Surface Raiders
Pocket Battleships / Heavy Cruisers
Example: Admiral Graf Spee
Auxiliary Cruisers
Example: Atlantis
Surface Raiders
Pocket Battleships & Heavy Cruisers
Six 11-inch guns
Eight 5.9-inch guns
Speed: 21 knots
Displacement: 16,200 tons
Admiral Graf Spee
War Cruise
August-December 1939
Sank 9 merchant ships
(50,000 tons)
Video
Scuttled, December 17, 1939
Off Montevideo, Uruguay
After battle with thee British cruisers
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
Circumnavigated the globe
Highest tonnage sunk of all surface raiders
• 22 ships, 146,000 tons
Next:
Lesson 22
WW II -- Second Battle of the Atlantic, Pt 2
End