Renkyō Line

The Renkyō Line began as the "South Manchuria Line" of the Russian-owned Chinese Eastern Railway running from Harbin to Port Arthur. Russia obtained the rights to build this line from Qing China; work began on 27 March 1898, and the 1,524 mm (5 ft 0 in) broad gauge line was opened to traffic in July 1903. Following Russia's defeat in the Russo-Japanese War, Japan gained the rights to operate the Harbin–Lüshun (Ryojun) section of the CER; the line was then converted from Russian broad gauge to the 1,067 mm (3 ft 6.0 in) Cape gauge used in Japan, to allow the use of rolling stock from Japan. The line was operated by the Imperial Japanese Army until it was taken over by the South Manchuria Railway Company (Mantetsu), established on 26 November 1906.^[2] Mantetsu immediately set to regauging the line again, this time from Cape gauge to 1,435 mm (4 ft 8.5 in) standard gauge.^[3]

Mantetsu created the Renkyō Line - then called the Manchu Main Line (満洲本線, Manshū Honsen, Mǎnzhōu Běnxiàn) - between Dairen and Mengjiatun (Mōkaton) on 1 April 1907, and extending it to Changchun (Chōshun) on 1 September 1907. Regauging of the entire line was completed in 1908, and on 27 May of that year through service between Dairen and Chōshun began on the all-standard gauge line. The Anpō Line, which connected to the Renkyō Line at Fengtian (Hōten) and was initially built as a 762 mm (2 ft 6.0 in) narrow-gauge line, was converted to standard gauge in November 1911, and from 15 June 1912 direct operation between Busan and Changchun began, via the Chosen Government Railway's Gyeongbu and Gyeongui Lines, the Anpō Line, and the Renkyō Line from Fengtian to Changchun. Double-tracking of the line from Sujiatun (Sokaton) to Dairen was completed on 27 October 1908, but it wasn't until 30 November 1918 that the section from Sujiatun to Fengtian was doubled. Between 1919 and 1926 the entire line was relaid with 100-lb/yd (50 kg/m) rail. The first colour light signals for automatic block signalling were installed on the Dalian–Jinzhou (Kinshū) and Fengtian–Sujiatun sections on 12 February 1924, and the entire section from Dalian to Fengtian received automatic blocking by 5 November 1933. On 15 July 1927, the line's name was changed from Manchu Main Line to Renchō Line (連長線; "Lianchang Line", Liáncháng Xiàn, in Chinese).

Using the Mukden Incident as a pretext to invade Manchuria, Japan created the puppet state of Manchukuo in March 1932;^[4] Changchun was designated the capital city, and was renamed Xinjing (Shinkyō), and the line was renamed once again, becoming the Renkyō Line at that time. The "Asia Express", a world-class limited express train,^[5] was introduced on 26 September 1934 between Dalian and Xinjing. The Manchukuo National Railway, which had taken over the remainder of the Chinese Eastern Railway, finished the conversion of the Jingbin Line from Xinjing to Harbin from broad gauge to standard gauge on 31 August 1935, and from 1 September the Asia Express service was extended to Harbin.

Japan's deteriorating situation in the Pacific War affected the line significantly. The Asia Express was suspended at the end of February 1943. The loss of air and sea superiority led to a drastic reduction in freight traffic to the port at Dalian, being instead redirected to Korean ports, via the North Chosen Line to the ports of Rajin and Unggi, and via the Anpō Line and the Chosen Government Railway to Busan. Between 1 August and 3 November 1944, the second track of the 180.3 km (112.0 mi) section between Sanshilibao (Sanjūrihō) and Dashiqiao (Daisekikyō) was removed, with the railways being used to upgrade Mantetsu's Anpō Line and the Manchukuo National Railway's Fengshan Line from Fengtian to Shanhaiguan.^[6]

On 9 August 1945, the Soviet Union invaded Manchukuo, and on the 14th, the USSR and the Republic of China signed a treaty of friendship; the signing of the treaty was announced on the 27th. Under the terms of this treaty, a Sino-Soviet joint enterprise was formed, called the China Changchun Railway, to operate the Renkyō Line (known as the Changda Line after Xinjing reverted to its original name, Changchun) and a number of lines formerly owned by the Manchukuo National Railway, including the Xinjing–Harbin Jingbin Line and the Harbin–Manzhouli Binzhou Line. Mantetsu was formally dissolved on 30 September 1945.^[7] The China Changchun Railway was transferred to China Railway in 1955, after which the Changda Line was split up, with the Dalian–Shenyang section becoming the Shenda Railway, and the Shenyang–Changchun section becoming part of the Beijing–Harbin Jingha Railway.