ON Convoys - Notable Battles Around ON and ONS Convoys

Notable Battles Around ON and ONS Convoys

The Outbound Northern convoys saw some of the major convoy battles of the Atlantic campaign; of the 40 convoys which lost 6 or more ships, 8 were in the ON series (of which 5 were Slow, and 3 were Fast) and one was in the ONS series.

• Convoy ON 67 was one of the few North Atlantic trade convoy of early 1942 to be attacked by multiple U-boats.

• Convoy ON 122 was the first to illustrate the defensive value of HF/DF and type 271 centimeter-wavelength radar.

• Convoy ON 127 was the only North Atlantic trade convoy of 1942 or 1943 where all U-boats deployed against the convoy launched torpedoes.

• Convoy ON 144 demonstrated the ability of Flower class corvettes equipped with type 271 centimeter-wavelength radar.

• Convoy ON 154 included the last Q-ship operation by the Royal Navy. Loss of 486 lives with 14 ships during the "Christmas Convoy" of December 1942 caused re-evaluation of Canadian convoy escorts.

• Convoy ON 166. Attacked in late February, 1943, ON 166 lost 13 merchant ships and the Convoy rescue ship Stockport. Three U-boats were destroyed and the USCG Treasury Class Cutter leading Escort Group A-3 was disabled.

• Convoy ONS 5. Attacked in April–May 1943, ONS 5 saw the loss of 12 ships, and the destruction of 6 U-boats, in a week long series of actions. It ushered in the period known as Black May and is widely regarded as the turning point in the Atlantic campaign.

• Convoys ONS 18/ON 202. Attacked in September 1943, these two convoys saw the loss of 6 ships and 3 escorts, for the destruction of 3 U-boats, in the first battle of KM's autumn offensive after Black May.