CHINA: The second phase of Chongqing Rail Transit’s Line 4opened from Tangjiatuo to Huangling on June 18, adding 32·6 route-km and 15 stations.
Construction began on January 25 2019, and local media reports suggest the project set a new record for speed of construction in Chongqing.
Line 4 now totals 48·5 km and 23 stations; 21·2 km of the latest extension is in tunnel, with the rest on an elevated alignment.
The main construction contractor for Phase 2 was China Railway Eighth Bureau, which used innovative techniques to cut energy consumption during construction by 35%, with component prefabrication to reduce construction time by 45%. Eight tunnel boring machines were used, reaching a record 589·5 m excavated per machine per month.
Line 4 currently joins Chongqing’s loop Line O at Min’andadao, with through services operated onto a southern branch of Line 5 at Tiaodeng. Construction of a 10·9 km western extension began on March 2 2021. This will separate Line 4 from the loop at Min’andadao, continuing via interchanges with other lines at Jizhoulu, Huahuiyuan, Dashiba and Yudaishan to terminate at Panguilu in Jiangbei, with four other intermediate stations.
