Convoy ONS 5

Convoy ONS 5
Part of World War II
Date29 April-6 May 1943
Location
Result British Victory
Belligerents
 Germany  United Kingdom
 Canada
Commanders and leaders
Admiral Karl Dönitz Convoy Comm: JK Brook RNR
Escort B7: Cdr Peter Gretton
Strength
Star 16 U-Boats
Finke 27 U-boats
42 ships
7 escorts
Casualties and losses
7 U-boats sunk
7 U-boats damaged
13 ships sunk (63,000 gross register tons (GRT))

ONS 5 was the 5th of the numbered ONS series of Slow trade convoys Outbound from the British Isles to North America. The North Atlantic battle surrounding it in May 1943 is regarded as the turning point of the Battle of the Atlantic in World War II. The battle ebbed and flowed over a period of a week, and involved more than 50 Allied ships and their escorts, and over 30 U-boats. It saw heavy losses on both sides. However it was almost the last Allied convoy to do so, while losses inflicted on attacking U-boats and U-boat groups became a besetting feature of the campaign; As such it is seen as the point when the tactical and strategic advantage passed to the Allies, and ushered in the period known to Nazi Germany's Kriegsmarine as Black May.