ALCO RSD-1 1,000 horsepower Co-Co locomotives. An additional 44 RSD-1s were built for use in Iran. These totalled only 57 locomotives so initially they were used to operate only the southern part of the Southern Division between Bandar Shahpur and Andimeshk. For traffic between Andimeshk and Tehran the USATC brought 91 S200 Class steam locomotives, designated class 42.400 in the Iranian State Railways numbering system. The USATC also introduced another 3,000 freight cars. In April 1943 another 18 ALCO RSD-1's entered service, enabling the USATC to return some LMS 2-8-0s to the British Middle East Command and extend diesel operation northwards, reaching Qom by September 1943 and regularly serving Tehran by May 1944. The USATC further increased freight traffic so that in 1944 it averaged 6,489 tons per day. "Aid to Russia" traffic ceased by May 1945 and in June the USATC withdrew its RSD-1's and returned control to the British authorities. Shortly afterwards the British restored the line to Iranian State Railways, the predecessor to the Islamic Republic of Iran Railways. After World War II The railway was extended from Bandar Shah to Gorgan in 1961. In 2014, the Kazakhstan-Turkmenistan-Iran railway link, part of the International North–South Transport Corridor, was completed and made operational, connecting Kazakhstan and Turkmenistan with Iran, with a new line connecting Gorgan to Etrek in Turkmenistan. The railways of former states of the Soviet Union use a Russian gauge, requiring the Iranian Railways to provide break-of-gauge services at the border with Turkmenistan. See also International Rankings of Iran in Transportation Transport in Iran Islamic Republic of Iran Railways Railway electrification in Iran Ladislaus von Rabcewicz References Sources Rail transport in Iran Middle East theatre of World War II World War II occupied territories British military occupations Soviet military occupations Battles and operations of World War II Military history of the Soviet Union during World War II Pahlavi Iran Wars involving the United Kingdom Military history of India during World War II Royal Engineers Soviet Army Iran–Soviet Union relations Military logistics of the United States Military railways Standard gauge railways in Iran Railway lines in Iran