Aerial photo taken on January 8, 2022 shows a test bullet train running on the new Chengdu-Kunming railway in Dechang County, Liangshan Yi Autonomous Prefecture, southwest China's Sichuan Province.(XINHUA) 

A railway linking Chengdu and Kunming, two major cities in southwest China, is now fully operational with the opening of its last section on December 26.

With a designed speed of 160 km per hour, the 915-km new line, which runs almost parallel to an existing railway link between Chengdu and Kunming, cuts the travel time from 19 hours to 7.5 hours.

The railway traverses various mountains and rivers, which posed challenges during its construction.

The new Chengdu-Kunming Railway features seven long tunnels -- with each measuring more than 10 km -- and 11 long-span bridges, said Wang Wei, a chief engineer from China Railway Eryuan Engineering Group Co., Ltd, which undertakes the designing work of the railway.

As a key project for China's West Development Strategy, the railway is expected to promote economic growth and the high-quality opening up of southwestern Chinese regions.