text: Other supply convoys The Arctic route was the shortest and most direct route for lend-lease aid to the USSR, though it was also the most dangerous. Some 3,964,000 tons of goods were shipped by the Arctic route; 7 percent was lost, while 93 percent arrived safely. This constituted some 23 percent of the total aid to the USSR during the war. The Persian Corridor was the longest route (and the only all-weather route) to the USSR, but was not fully operational until mid-1942. Thereafter it saw the passage of 4,160,000 tons of goods, 27 percent of the total. The Pacific Route opened in late summer 1941, but was affected by the start of hostilities between Japan and the US with the Attack on Pearl Harbor. After December 1941, only Soviet ships could be used and as Japan and the USSR observed a strict neutrality towards each other, only non-military goods could be transported. Nevertheless, 8,244,000 tons of goods went by this route, 50 percent of the total.
  A branch of the Pacific Route began carrying goods through the Bering Strait to the Soviet Arctic coast in June 1942. From July through September small Soviet convoys assembled in Providence Bay, Siberia to be escorted north through the Bering Strait and west along the Northern Sea Route by icebreakers and Lend-Lease Admirable class minesweepers. A total of 452,393 tons passed through the Bering Strait aboard 120 ships. Part of this northern tonnage was fuel for the airfields along the Alaska-Siberia Air Route. Provisions for the airfields were transferred to river vessels and barges on the estuaries of large Siberian rivers. Remaining ships continued westbound and were the only seaborne cargoes to reach Archangel while J W convoys were suspended through the summers of 1943 and 1944.