China's longest subway loop line under construction to pass under Yangtze River

As a domestically made shield tunneling machine bored ahead, Line 12 of the Wuhan metro, which will become China's longest subway loop line once completed, began to extend under the Yangtze River on Sunday.

The 59.9-km line is the first subway loop line in Wuhan, capital of central China's Hubei Province, and also the longest nationwide.

Line 12 will connect the three towns of Wuhan, namely Wuchang, Hankou and Hanyang, stretching across seven administrative districts. Meanwhile, the line is designed to go under the Yangtze River twice, the Hanjiang River and two lakes.

The shield tunneling machine used in the project is produced by China Railway Tunnel Group Co., Ltd. and China Railway Engineering Equipment Group Co., Ltd.

The machine weighs about 2,900 tonnes, with an overall length of about 105 meters, and a diameter of 12.56 meters, twice the width of ordinary shield tunneling machines used for subway construction projects.

According to Wuhan Metro Group, the Line 12 will ease the pressure on Wuhan's urban passenger flow upon operation, thus further improving the city's comprehensive transportation system.