One of the world’s largest tunnel boring machines is ready for delivery

It was announced on June 4 by German tunnel boring machine (TBM) manufacturer, Herrenknecht AG, that one of the world’s largest TBMs is currently being dismantled for delivery.

The TBM, called Shanhe, is of the Mixshield type and measures 17.5 meters in diameter. This Mixshield type utilizes chamber pressure controlled automatically by an air cushion, in addition to the conventional slurry method.

This enables the usage of Mixshield TBMs in water pressure conditions higher than 15 bar, heterogeneous geologies, and TBM diameters up to 19 meters.

It is noteworthy that machines of this diameter have only been used twice before in the history of tunneling, including the largest ever in Hong Kong, in 2015, which measured 17.63 meters and was also a Herrenknecht Mixshield.

The machine is being shipped to the Chinese city of Jinan, about 400 kilometers south of Beijing, which has a population of nine million and is the capital of the Shandong province.

Once there, it is going to be reassembled and used for the construction of a 3,290 m long tunnel under the Yellow River.

The single tunnel is going to accommodate two-way road traffic within two stories, featuring three lanes each.

Site-specific conditions under the Yellow River include heterogeneous geology and a 7.5 bar water pressure.

Finally, construction is expected to commence in late 2024.