BX convoys

The BX convoys were a World War II series of convoys across the Gulf of Maine from Boston to HalifaX. These convoys were escorted by the Western Local Escort Force (WLEF) of the Royal Canadian Navy to protect coastal shipping in transit between North American loading ports and trans-Atlantic convoy assembly points in Nova Scotia.

Allied war materials had been transported from North America to the United Kingdom 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 beginning in September 1941. Declaration of war on 8 December 1941 removed United States neutrality assertions which had previously protected trade shipping in the Western Atlantic. Although the United States was slow to convoy coastal shipping, the Royal Canadian Navy established the WLEF in February 1942.

WLEF escorted the first BX convoy from Saint John, New Brunswick on 21 March 1942 and reached Halifax the following day. Ten of the first twelve BX convoys originated in Saint John. BX 4 was the first convoy originating in Boston on 3 April 1942, and BX 8 sailed from Boston on 18 April. BX 13 was the first convoy of the series to sail in multiple sections. The main convoy of eleven merchant ships left Boston on 3 May, and two ships left Saint John as convoy BX 13A on 5 May. BX 14 was the first of the series to sail from Portland, Maine on 7 May. These early WLEF convoys sailed with as few as a single ship as the United States struggled to efficiently control sailing dates. BX 20 on 24 May was the first to include more than eleven ships. June convoys sailed in two sections with a main convoy like BX 25 with 43 ships leaving Boston on 17 June and a smaller convoy of seven ships leaving Boston two days later as BX 25B.

...
Wikipedia