Convoy ON 67 was an Allied transatlantic convoy that sailed during the Battle of the Atlantic in World War II. It was part of the "ON" series of convoys, which typically travelled westbound from the British Isles towards North America. The convoy gained notoriety due to a significant U-boat attack it sustained in February 1942, resulting in substantial losses.
Background By early 1942, the Battle of the Atlantic was intensifying, with German U-boats, operating in "wolf packs," targeting Allied shipping. Convoys were the primary method of protecting merchant vessels transporting vital supplies across the Atlantic. The "ON" series designated convoys originating in the UK (or generally from European waters) bound for ports in North America.
Formation and Route Convoy ON 67 comprised 37 merchant ships. It departed Liverpool on February 15, 1942, bound for various destinations in North America. Its initial escort consisted of elements of the Western Approaches Command. As it proceeded into the Mid-Atlantic, it was to be met and protected by Mid-Ocean Escort Force (MOEF) Group B6, which included the British destroyer HMS Burza (Polish-manned), the British corvette HMS Dianthus, and the Canadian corvettes HMCS Chilliwack and HMCS Baddeck.
U-boat Attack The convoy was detected by a German U-boat "wolf pack" consisting of at least seven U-boats (U-558, U-587, U-155, U-150, U-213, U-432, U-572) positioned in the Western Atlantic. The attacks commenced on February 21, 1942, and continued for several days.
- February 21: U-587 attacked, sinking one merchant ship.
- February 22: U-boat attacks intensified. Another merchant vessel was sunk by U-587, and U-558 sank two more ships. During the night, the escort fought back. HMCS Baddeck detected U-587 and, in cooperation with HMCS Chilliwack and a patrolling Catalina aircraft, launched a depth charge attack that ultimately sank U-587 with all hands. Despite this success, other U-boats continued their assaults.
- February 23: U-558 sank another ship, bringing its total to four. U-155 also joined the attack, sinking two more merchant ships.
- February 24: Attacks tapered off as the convoy pressed westward, having outrun some of the attacking U-boats or as the U-boats exhausted their torpedoes or fuel.
Losses and Outcome In total, Convoy ON 67 lost nine merchant ships, amounting to approximately 54,000 gross register tons (GRT). This represented a significant loss rate for the convoy. On the German side, one U-boat, U-587, was sunk by the combined efforts of the convoy's escort.
Significance Convoy ON 67 is notable as one of the significant convoy battles of early 1942, illustrating the ongoing challenges faced by Allied convoys in the Mid-Atlantic Gap before more advanced anti-submarine warfare (ASW) tactics, equipment, and air cover were consistently available. The battle highlighted the effectiveness of coordinated wolf pack attacks and the vulnerability of convoys even with dedicated escorts, underscoring the critical need for continuous innovation in ASW doctrine and technology. Despite the losses, the majority of the convoy's ships successfully reached their destinations, demonstrating the enduring protective role of the convoy system.