The Chengdu–Kunming railway or Chengkun railway (), is a major trunkline railroad in southwestern China between Chengdu, the capital of Sichuan Province and Kunming, the capital of Yunnan Province. The line is long and traverses rugged terrain from the Sichuan Basin to the Yunnan-Guizhou Plateau. The line was built between 1958 and 1970. Major cities along route include Chengdu, Pengshan, Jiajiang, Emei, Ebian, Ganluo, Xide, Xichang, Dechang, Miyi and Panzhihua in Sichuan Province and Yuanmou, Lufeng, Anning and Kunming in Yunnan Province. Construction of a largely new double-track line started in 2010 and is expected to be completed in 2023. A northern section of the old line is now called the Emei–Panzhihua railway (shortened to E-Pan railway) and a southern section is called the Yuanmou–Kunming railway (shortened to Yuankun railway). History Planning of the Chengdu–Kunming railway began in 1952 with several routes under consideration. An eastern route would have run via Neijiang, Zigong, Yibin, Shuifu, Yanjin. Yiliang, Malong and Songming. A central route would have taken a similar route as far as Yibin and continued via Pingshan, Suijiang, Yongshan, Daguan, Qiaojia, Huize, Dongchuan and Songming. A western route would run via Meishan, Leshan, Ebian Yi, Ganluo, Xide, Xichang, Dechang, Huili and Guangtong. Soviet advisers recommended the central route as they considered the western route to be too difficult to build, because of its geography and geology, and that it could not be maintained because it would be prone to flooding, mudslides and earthquakes. Nevertheless, a committee headed by Zhou Enlai preferred the western route and this was eventually confirmed. It was considered to give access to important mineral deposits, passed through areas inhabited by ethnic minorities and had advantages for national defence. The eastern route was later used for much of the Neijiang–Kunming railway, which was completed in 2001. The central route has similarities to the route of the proposed high-speed line between Chengdu and Kunming. Construction began in 1958 during the Great Leap Forward and expanded to full-scale in 1964. Work was accelerated due to the American bombing of North Vietnam after the passage of the Gulf of Tonkin Resolution. The only rail connection to Kunming at that time ran through North Vietnam. In July 1970, the line was completed and entered into operation in January 1971. The government published a pictorial in 1976 showing pictures of the construction and extreme terrain that required hundreds of tunnels and bridges.