Following the occupation of Iran in 1941, WD locomotives were required to operate the Persian Corridor supply route, delivering war materials to the Soviet Union via the Trans-Iranian Railway. 163 8F were dispatched to Iran in 1941-42, but only 143 arrived (12 being lost at sea (246-444, 445, 608, 617, 619, 622 (latter 4 former LMS 8066, 8068, 8071, 8087)) and 8 returned to Britain with sea damage). These operated as Iranian State Railways' Class 41.