Allied war materials had been transported from North America to the British Isles in HX convoys since 1939 and in slower SC convoys since 1940. These convoys were escorted by the Royal Navy and Royal Canadian Navy. The United States Navy provided a few escorts to HX and SC convoys from September 1941 through April 1943. UG convoys were established as a second, more direct, supply route to support the invasion of North Africa. The first convoy, designated UGF 1, was the invasion convoy sailing on 24 October 1942 and arriving on 8 November 1942. The F designated a convoy of faster ships. Thereafter, fast and slow eastbound and westbound convoys on this southern route were given four separate numbering sequences beginning with 2.