HH104 AMERICAN NAVAL HISTORY

THE BATTLE OF THE ATLANTIC

 

GENERAL

 Radar gave German U-boats trouble from 1940 on.  When US entered war, U-boats came into east coast waters and found merchants plentiful and still on vulnerable peacetime routes.

Japs and Germans realized too late that they needed to fight globally, not regionally, to win

German surface fleet was trapped by British in the North Sea

 

ARCADIA CONFERENCE

Between US and Brits to discuss strategy.  (24 Dec to 14 Jan).  Decided to use Plan Rainbow and ABC-1.  Germans first-doctirine established.  Allies not yet ready for joint fighting

 

ADM KING

New CNO and CinC US Fleet.  Post-Midway believed US Pacific Fleet needed to press the attack.  Under pressure at first because of U-Boats on the East Coast; not until Spring 1942 where he has enough ships to escort all convoys; extends protection to the Caribbean

 

GERMAN NAVAL WARFARE

    ADM “The Lion” DONITZ – CDR of U-Boats on East Coast of US.  As U-Boat warfare came under control, he pushed for new subs with snorkels and torpedoes that homed on a ship’s propellors.  Believed in wolfpacks, Tonnage War.  Shortly was the leader of Germany when the 3rd Reich fell.

 

    PAUKENSCHLAG – U-boat’s “Operation Drumbeat” was against US merchants on US coast; mined US coast in Jun ‘42

    WOLFPACKS – 1 sub lures DDs away from convoy and then the other subs attack the convoy

 

U.S. UNPREPARED

No coastal convoys.  Cities lights silhouetted ships who turned their lights off.  No escort vessels or patrol planes.

 

PERSONNEL CHANGES

Nimitz, ex-submariner, replaces Kimmel.

May 1942 – Robinson becomes first black commissioned US Navy Officer

30 July 1942 – WAVES (Women Accepted for Volunteer Emergency Service) created by Congress

 

 

FIGHTING GERMAN U-BOATS

    CODE BREAKERS (general)

Comdr. Rochefort led cryptanaysts based in Pearl Harbor.  Decoded message that allowed Allies to manuever to protect the Australian region and slow the Jap advance with the Battle of the Coral Sea.

“Fresh water” – Codebreakers wasn’t sure if AF in Jap code meant Miday so they sent a message in plain English saying Midway was low on water.  Two days later, Jap sent a coded message saying AF was low on water, confirming AF was Midway.

Plans for Midway was in older code that the US new how to crack but times were in a different code.  Rochefort worked 72 hours straight without breaking it but then broke it May 24th – the attack on the Aleutians would be in 10 days, and the Jap carriers in 11 days.

Enigma Machine – captured by Brits; Intelligence decoded from Enigma called ULTRA; Germans later added a wheel to the machine and the Allies had to it to decipher the new code

 

    CONVOY ESCORTS

Black Pit / Gap – mid-Atlantic where most convoys were largely unprotected from U-boats

28 April 1943 51 subs came to attack an Allied 42-ship convoy but fogged blinded the subs after twelve kills.  Allied radar continued to hunt the subs and six were sunk.  The next three weeks results in only 5 lost ships to 13 subs.  In May alone Donitz lost 41 subs (from about 200) – his greatest losses ever and the majority of U-boats were withdrawn from the North Atlantic indefinately (withdrew to Central Atlantic, covered by US 10th Fleet and Brit air).

Radar, bombs, and guns used with new weapons – contact explosive forward-thrown “hedgehog” and “squid” allowed destroyers to keep sonar contact during depth charging and FIDO, hominh Antisub torpedo.

 

    ELECTRONIC WARFARE

Radar used by both sides.  First recognized by Germans in 1903 and radar guided guns by Germans in 1941.  French Adm Darlan gave METOX (1.5m wavelength radar) to Donitz

Allies used more advanced radar (magnetron) made by Brits which operated on shorter wavelengths making it more accurate, longer range, and undetectable to METOX.

Allies also used high-frequency direction finders allowing them to home in on U-boat signals (unknown to Germans)

 

    AIRCRAFT

Liberators – long-range US planes used to escort convoys.  Eventually placed in Iceland which achieved full daytime coverage of the Black Pit.

 

Bismarck

9 15” guns fired 1 ton shells 20mi; crew of 2,000; very elegant.  HMS Hood, Brits best ship, attacks the Bismarck but is sunk in a mere 10min.  Bismarck sunk two weeks into its maiden voyage (airship sighted it then old Brit biplanes bomb it disabling its steering [no better planes available].  Royal Navy comes in and sinks the disabled ship.  Illustrated the weakness of battleships to aircraft.)

 

BREACHING FORTRESS EUROPE

     INVASION OF NORTH AFRICA – US wanted cross-channel invasion, but Brits wanted to avoid a direct invasion…

Operation Torch – 5 Sept 1942 the plan agreed on.  US sent (Nov ’42) 113,000 troops mostly escorted British ships to North Africa (Casablanca, Oran, Algiers sites of invasion) and both sides contributed equal air power.  Biggest convoy ever mounted with 650 warships and transports.  Escort carriers used for the first time.  Landing force cdr by Patton.  Naval force by Hewitt.  Eisenhower overall cdr.  ***Opens Med Sea and tests amphib tactics.

French ships / sailors (German orders) attack US; US sinks the entire Navy except one ship and the scuttled ships.

 

    THE SICILY CAMPAIGN

Operation Husky: US to advance through Sardinia to Silicy and on to Italy.  1st attempt to get foothold on Axis territory.

Italy removes Mussolini and wants to join the Allies but Allies continue to invade to dislodge Germans; Italy surr 1943

 

    INVASION OF ITALY (Longest campaign of the war; 602 days)

Operation Avalanche: 2,500 ships (Biggest armada ever) secure beaches in 48hrs.

Operation Shingle: moves the line to Rome

Final Allied Offensive in Italy caused the surrender of Germany 2 May ‘45

        Casualties: 312,000 Americnas, 435,000 Germans