Why Dönitz Couldn't Explain How 43 U-Boats Lost To A Convoy Guarded By 7 Ships
Forgotten Naval History
66,952 views
Convoy ONS-5, May 1943: 43 U-boats attacked a convoy guarded by seven warships, and the seven won. Karl Dönitz wrote down why in his own war diary. He was wrong.
This is the story of the most one-sided concentration of force in the Battle of the Atlantic, and of the six hours on the Grand Banks of Newfoundland that broke the German wolfpack system for good. Escort Group B7 fought this battle without its commander, without working sonar aboard the senior ship, and without Bletchley Park, whose codebreakers had been locked out of the U-boat cypher since 26 April. Six U-boats were destroyed. Not one merchant ship was torpedoed during the five hours that decided it.
What Dönitz could not work out was how. His own scientists had ruled out the answer in January 1943.
WHAT THIS VIDEO COVERS
Why the Atlantic convoy system nearly collapsed in March 1943, and what convoys HX-229 and SC-122 cost
Rudeltaktik, the German wolfpack doctrine, and why it worked for three years
The January 1943 decision by German radar research to abandon centimetric wavelengths, and the price of that decision
Metox, the U-boat radar receiver that could not hear the set hunting it
Escort Group B7, the Flower-class corvettes, and the reservist and Hostilities Only crews who manned them
The Western Approaches Tactical Unit in Liverpool, Captain Gilbert Roberts, and the Wrens who invented the counter-attack drills on a linoleum floor
Commander Peter Gretton's decision to leave his own convoy on 3 May with four percent fuel remaining
Lieutenant Commander Robert Sherwood, an Irish Sea ferry officer, taking command of the battle with dead ASDIC
The night action of 5 and 6 May 1943, hour by hour, from the ships' logs and Reports of Proceedings
HMS Oribi ramming U-125 at 200 yards, and HMS Snowflake finding the wreck in 100-yard visibility
Type 271 centimetric radar, HF/DF, and the Hedgehog ahead-throwing mortar
Admiral Sir Max Horton's support groups and why they arrived at dawn
What the BdU war diary actually recorded on 6 May, in the German staff's own words
The Metox self-radiation red herring, and why Dönitz switched off the wrong device in August 1943
Black May 1943, the withdrawal order of 24 May, and the loss of Dönitz's own son aboard U-954
The honest ledger: 13 merchant ships lost, 61,958 tons, and what the escorts did not achieve
PRIMARY RESEARCH SOURCES
BdU Kriegstagebuch, U-boat Command War Diary, entry for 6 May 1943, archival reference PG 30323, NARA microfilm T1022 Roll 4064, Office of Naval Intelligence translation
HMS Tay, Report of Proceedings, Lieutenant Commander R. E. Sherwood, acting Senior Officer Escort
Comments of Senior Officer, Close Escort, HMS Duncan, Commander P. W. Gretton
Endorsement of Commander-in-Chief Western Approaches, Admiral Sir Max Horton, dated 10 July 1943
HMS Snowflake, ship's log, Incident Snow 10, 6 May 1943
Stephen Roskill, The War at Sea 1939 to 1945, Volume II, official history
Axel Niestlé, German U-Boat Losses During World War II, for post-war verified kill attribution
Jürgen Rohwer, Axis Submarine Successes of World War Two
uboat.net, boat-by-boat and convoy battle records
uboatarchive.net, transcribed Admiralty escort reports
FURTHER READING
Peter Gretton, Convoy Escort Commander, the memoir of B7's senior officer
Peter Gretton, Crisis Convoy: The Story of HX231
Michael Gannon, Black May, the fullest single-volume account of May 1943
Clay Blair, Hitler's U-Boat War, Volume II, The Hunted 1942 to 1945
Marc Milner, North Atlantic Run and The Battle of the Atlantic
David Syrett, The Defeat of the German U-Boats
Karl Dönitz, Ten Years and Twenty Days, the German commander's own account
Simon Parkin, A Game of Birds and Wolves, on the Western Approaches Tactical Unit and the Wrens
A NOTE ON THE EVIDENCE
German records do not name ONS-5. The U-boat Command logged this action as Convoy Number 36 and misidentified it as ON 180. The war diary explains the defeat rather than expressing bewilderment at it, blaming fog first and radar second. The genuine and documented German confusion, over centimetric radar and the Metox receiver, belongs to the May 1943 campaign as a whole. This video says so plainly rather than claiming a quotation that does not exist. Post-war reattributions by Niestlé have been used throughout, so several kill credits here differ from older popular accounts.
If your father, grandfather or great-uncle served in the escorts, in the corvettes, the frigates or the rescue trawlers, leave his name and his ship in the comments. That is how the memory survives.
Forgotten Naval History covers the ships, weapons and crews the record almost lost. Subscribe for long-form Royal Navy history, told carefully and sourced properly.
#BattleOfTheAtlantic #RoyalNavy #NavalHistory #WW2History
20 Comments
In May 43 the Kriegsmarine lost in Total 41 U-boats.
Yes he knew it was war but the sinking of U192 haunted him.
He told me that when they reached either Murmansk or Archangel, Soviet officials and citizenry (in fear of their own lives no doubt) gave a cold shoulder to the men who’d spent weeks at sea struggling through storms and freezing seas carrying ammunition, tanks and aircraft to help keep the Red Army in the fight.
Why Dönitz Couldn't Explain How 43 U-Boats Lost To A Convoy Guarded By 7 Ships
Forgotten Naval History
66,952 views
Convoy ONS-5, May 1943: 43 U-boats attacked a convoy guarded by seven warships, and the seven won. Karl Dönitz wrote down why in his own war diary. He was wrong.
This is the story of the most one-sided concentration of force in the Battle of the Atlantic, and of the six hours on the Grand Banks of Newfoundland that broke the German wolfpack system for good. Escort Group B7 fought this battle without its commander, without working sonar aboard the senior ship, and without Bletchley Park, whose codebreakers had been locked out of the U-boat cypher since 26 April. Six U-boats were destroyed. Not one merchant ship was torpedoed during the five hours that decided it.
What Dönitz could not work out was how. His own scientists had ruled out the answer in January 1943.
WHAT THIS VIDEO COVERS
Why the Atlantic convoy system nearly collapsed in March 1943, and what convoys HX-229 and SC-122 cost
Rudeltaktik, the German wolfpack doctrine, and why it worked for three years
The January 1943 decision by German radar research to abandon centimetric wavelengths, and the price of that decision
Metox, the U-boat radar receiver that could not hear the set hunting it
Escort Group B7, the Flower-class corvettes, and the reservist and Hostilities Only crews who manned them
The Western Approaches Tactical Unit in Liverpool, Captain Gilbert Roberts, and the Wrens who invented the counter-attack drills on a linoleum floor
Commander Peter Gretton's decision to leave his own convoy on 3 May with four percent fuel remaining
Lieutenant Commander Robert Sherwood, an Irish Sea ferry officer, taking command of the battle with dead ASDIC
The night action of 5 and 6 May 1943, hour by hour, from the ships' logs and Reports of Proceedings
HMS Oribi ramming U-125 at 200 yards, and HMS Snowflake finding the wreck in 100-yard visibility
Type 271 centimetric radar, HF/DF, and the Hedgehog ahead-throwing mortar
Admiral Sir Max Horton's support groups and why they arrived at dawn
What the BdU war diary actually recorded on 6 May, in the German staff's own words
The Metox self-radiation red herring, and why Dönitz switched off the wrong device in August 1943
Black May 1943, the withdrawal order of 24 May, and the loss of Dönitz's own son aboard U-954
The honest ledger: 13 merchant ships lost, 61,958 tons, and what the escorts did not achieve
PRIMARY RESEARCH SOURCES
BdU Kriegstagebuch, U-boat Command War Diary, entry for 6 May 1943, archival reference PG 30323, NARA microfilm T1022 Roll 4064, Office of Naval Intelligence translation
HMS Tay, Report of Proceedings, Lieutenant Commander R. E. Sherwood, acting Senior Officer Escort
Comments of Senior Officer, Close Escort, HMS Duncan, Commander P. W. Gretton
Endorsement of Commander-in-Chief Western Approaches, Admiral Sir Max Horton, dated 10 July 1943
HMS Snowflake, ship's log, Incident Snow 10, 6 May 1943
Stephen Roskill, The War at Sea 1939 to 1945, Volume II, official history
Axel Niestlé, German U-Boat Losses During World War II, for post-war verified kill attribution
Jürgen Rohwer, Axis Submarine Successes of World War Two
uboat.net, boat-by-boat and convoy battle records
uboatarchive.net, transcribed Admiralty escort reports
FURTHER READING
Peter Gretton, Convoy Escort Commander, the memoir of B7's senior officer
Peter Gretton, Crisis Convoy: The Story of HX231
Michael Gannon, Black May, the fullest single-volume account of May 1943
Clay Blair, Hitler's U-Boat War, Volume II, The Hunted 1942 to 1945
Marc Milner, North Atlantic Run and The Battle of the Atlantic
David Syrett, The Defeat of the German U-Boats
Karl Dönitz, Ten Years and Twenty Days, the German commander's own account
Simon Parkin, A Game of Birds and Wolves, on the Western Approaches Tactical Unit and the Wrens
A NOTE ON THE EVIDENCE
German records do not name ONS-5. The U-boat Command logged this action as Convoy Number 36 and misidentified it as ON 180. The war diary explains the defeat rather than expressing bewilderment at it, blaming fog first and radar second. The genuine and documented German confusion, over centimetric radar and the Metox receiver, belongs to the May 1943 campaign as a whole. This video says so plainly rather than claiming a quotation that does not exist. Post-war reattributions by Niestlé have been used throughout, so several kill credits here differ from older popular accounts.
If your father, grandfather or great-uncle served in the escorts, in the corvettes, the frigates or the rescue trawlers, leave his name and his ship in the comments. That is how the memory survives.
Forgotten Naval History covers the ships, weapons and crews the record almost lost. Subscribe for long-form Royal Navy history, told carefully and sourced properly.
#BattleOfTheAtlantic #RoyalNavy #NavalHistory #WW2History