SHANGHAI, April 21 (Xinhua) -- Shanghai Metro Line 22, the city's first rail transit project to cross the Yangtze River, completed track laying on Tuesday, marking a new step forward in the integrated development of the Yangtze River Delta.

When operational, the line, also known as the Chongming Line, will help transform Chongming into a world-class ecological island, bring Chongming District closer to downtown Shanghai, improve regional transport connectivity, and provide a fresh boost to the integrated development of the Yangtze River Delta. Chongming Island is China's third-largest island and was formed by sediment deposited by the Yangtze River.

Running from Jinji Road Station in Shanghai's Pudong New Area to Yu'an Station on Chongming Island, Line 22 stretches over 42 kilometers at a designed speed of 120 kilometers per hour. The line crosses the Yangtze River twice via Changxing Island and features eight stations in total.

To overcome challenges such as excavation along the ultra-long river-crossing section, high water pressure under the riverbed, and complex geological conditions, the construction team introduced innovative tooling and processes, enhanced precision monitoring and regulation, and deployed intelligent construction equipment, according to Qu Ming, a project manager at Shanghai Shentong Metro Group Co., Ltd.

In the coming months, the project contractors will carry out critical work such as precision track adjustment, station decoration, and system testing, with the goal of finishing the line by the end of the year, Qu added.

Shanghai is accelerating the development of a multi-level rail transit system. The city currently operates 21 rail transit lines, with a combined network length of 906 kilometers.