Battle of the Atlantic Hodder CEW c3s6, pgs 139-142

Battle of the Atlantic

Longest Campaign of the War Sep 9, 1939 – May 8, 1945 Thousands of ships More than 100 convoy battles Maybe 1000 single-ship encounters

Sep 1939 – May 1945 British Royal Navy Royal Canadian Navy Allies Axis British Royal Navy Royal Canadian Navy US Navy (after Sep 1941) Allied merchant shipping German Kriegsmarine U-boats German Luftwaffe aircraft Italian Royal Navy (after June 1940)

Goals Allies Axis Blockade Great Britain Blockade Germany Keep Britain supplied w/ over 1 million tons per week Deliver war supplies to USSR Carry out longest amphibious invasion in history (from US to North Africa, 1942) Defeat the U-boat threat (considered requisite for turning the tide of the war) Blockade Great Britain Use surface ships and U-boats to raid Europe-bound convoys From 1942, prevent the buildup of Allied forces for invasion of Europe

Costs Allies Axis Germany ~30,000 sailors killed 783 submarines lost 36,200 sailors killed 36,000 merchant seamen killed 3,500 merchant vessels 175 warships 741 RAF Coastal Command Aircraft lost in anti-submarine sorties Germany ~30,000 sailors killed 783 submarines lost Italy ~500 killed 17 submarines lost

Battle of Rio Plate, Uruguay 12 Dec 1939 - Pocket battleship Admiral Graf Spee vs. 1 heavy, 2 light Royal Navy cruisers German ship damaged, unable to find port for repairs; scuttled off Montevideo German tactical victory, Allied strategic victory Reinforces Hitler’s low opinion of surface fleet Captain Langsdorff commits suicide in Buenos Aires, Dec 19 Churchill’s reputation enhanced

The Wolfpack

Wolfpack Command and Control Older, slower wolves set pace for pack Group of strong Betas are positioned to respond to threats Leader follows, controlling the group, deciding where to go, anticipating threats, imposing a spirit of mutual aid, and providing reassurance that no member will be left behind

Works the same, on water and on Land

German “Rudeltaktik” Kriegsmarine develops Rudeltaktik for attacking convoys with subs Subs in regular contact w/ HQ Pickets locate convoys Sub Commander decides if and when to assemble a rudel (pack); determines rendezvous point On-scene commander decides if there are enough U-boats in the rudel for an attack WEAKNESS: Heavily dependent on secure radio communication

US Adaptations US Navy later uses similar “wolfpack tactics” vs. Japanese in the Pacific Sailed in 3-boat groups that had considerably more freedom to act than their German counterparts Tactics abandoned during Cold War better weps meant attacking in force no longer necessary (or wise) Soviets adopted “Bastion Strategy” for fielding and defending ballistic nuclear subs Basically, they operated in closed seas, like the Arctic

Fighting the Subs: Convoys

Convoy Routes – “Air Gap”

Fighting the Subs: Depth Charges

Undated; Destroyer Escort dropping Depth Charges

Fighting the Subs: Convoy Escorts

Fighting the Subs: Destroyers & Destroyer Escorts Destroyers could be configured in many different ways Troop carriers Armed supply ships Minesweepers Anti-Submarine Destroyer Escorts: small, fast ships designed to protect larger or more valuable ships

Fighting the Subs: Aircraft

Aircraft Carriers Developed in 1920s-30s – the first ones were, um, rather ungainly…

George Washington Parke Custis, US Civil War, 1862 Imperial Japanese aircraft carrier Akagi in Osaka in 1934. She will be lost at the Battle of Midway in 1942

IJN Honsho, 1922 USS Birmingham, 1910 HMS Argus, 1918 USS Saratoga, 1935

Carrier Escorts Purpose-built or converted merchant ships to protect convoys 1/3 the size of fleet carriers 20-30 planes, mostly anti-sub Over 100 constructed or converted during war

Project Habakkuk British plan to create a gigantic, unsinkable aircraft carrier made of ice reinforced with wood pulp (“Pykerete”) Initial enthusiasm wanes as costs become apparent and Churchill secures use of Portuguese bases in the Azores; no longer pursued by end of 1943