[1] ON 92 was a west-bound convoy of 42 ships, either in ballast or carrying trade goods, and sailed from Liverpool on 6 May 1942 bound for ports in North America.

J Heffernan as Senior Officer Escort), the United States Coast Guard cutter Spencer, and four Royal Canadian Navy corvettes Algoma, Arvida, Bittersweet and Shediac.

[5] After making rendezvous with its ocean escort ON 92 proceeded west, following along the great circle route to reduce distance.

However German intelligence (B-Dienst) was aware of its passage, and U-boat Command (BdU) was able to send group "Hecht" in pursuit.

Its transmissions were detected by Bury, which was confirmed by the Admiralty that afternoon but Heffernan made no response until 1700, when he led Gleaves and Spencer in a wide sweep around the convoy.

After sunset the commodore ordered evasive maneuvers, but without success, and at 2300 U-124 attacked, sinking Empire Dell and damaging Llanover.

At 1300 Heffernan again detached Gleaves and Spencer in a sweep around the convoy; at 1943 Spencer sighted two U-boats 27 miles (43 km) northwest of the convoy, and engaged with gunfire, while at the same time Gleaves made a sonar contact 18 miles (29 km) southeast and again began an anti-submarine hunt.

[10] The convoy was joined by units of Western Local Escort Force on 17 May and made port at Halifax on 21 May.