A breakthrough in construction of the first railway tunnel to be built through the Helan Mountains in northwest China’s Ningxia Hui Autonomous Region has been announced.

The area has complex geology and is both environmentally and historically sensitive, with the Great Wall of China passing over the route of the rail tunnel.

Construction of the main tunnel has begun with excavation teams working at both ends of the bore, which will be a single-track tunnel with a total length of 8.8km taking the Yinchuan - Bayanhot line through the mountains. When completed the tunnel will be used solely for passenger traffic.

The complex geological conditions have made construction highly challenging due to the possibility of rockfalls, roof collapse and water and mud inflows. In addition, the Helan Mountains are a national nature reserve with a fragile ecological environment and the project teams are responsible for tunnelling works underneath part of the Great Wall.

“During construction of the tunnel section under the Great Wall, we used mechanical excavation instead of blasting excavation to minimise the impact,” says chief engineer responsible for tunnel construction, Mr He Lilei.

Yinchuan station in Ningxia will be the starting point for the new line. Photo credit: N509FZ/Wikipedia

Scheduled to open in 2026, the Yinchuan - Bayanhot railway will be electrified and have a design speed of 200km/h. It will link the Ningxia Hui and Inner Mongolia autonomous regions, helping to improve connectivity between Ningxia and surrounding cities such as Hohhot and X’ian. The total investment in the project is nearly Yuan 6.9bn ($US 1bn).

Preliminary work and construction design was undertaken by China National Railway Group in conjunction with the Inner Mongolia and Ningxia Hui autonomous regional governments.

Work is now being undertaken by China Railway Lantie Group, also working with the regional authorities.

The new line will start at the south end of Yinchuan station on the Yinxi high-speed line in Ningxia and will have two stations at Barun Bieli and Bayanhot in Inner Mongolia. It is expected to play an important role in opening up these regions to economic and social development, including tourism, by linking them to China’s high-speed network. Of the route length, 75km will be in Inner Mongolia and 40km in Ningxia.

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