Railway-Beijing-Zhangjiakou Railway

China from Fengtai to Zhangjiakou via Juyongguan, Shacheng and Xuanhua. The total length is 201.2km. It is now the first paragraph of beijing-baotou railway. The Beijing-Zhangjiakou Railway was established in September 1905 and opened to traffic in August 1909. At that time, Zhan Tianyou was appointed as the chief engineer of Beijing-Zhangjiakou Railway Bureau by the Qing government (later became the general manager of Beijing-Zhangjiakou Railway Bureau). Railway engineering is arduous, for example, the terrain from Juyongguan and Badaling to the south exit of Kangzhuang is complicated. In order to cross the steep ravine of Dujun Mountain in Yanshan Mountains, 3.3% ramps and zigzag lines were adopted in the 22km section, and four tunnels were excavated, of which Badaling tunnel was 109 1m long.