(Yicai Global) Oct. 17 -- A dual-mode shield machine developed by China Railway Hua Sui United Heavy Machinery Co. (CRHS) rolled off the production line yesterday. The piece of tunnel boring equipment helps provide an optimal solution for safe cabin-opening in complex strata.

It is the world's first dual-mode shield machine with a frozen cutter head and a composite grouting system.

The dual-mode shield machine can help overcome the shortcomings of a single-mode shield machine for construction in complex strata. Such dual-mode shield machines allow for quick switches between two different boring modes based on changes in conditions, ensuring the quality and efficiency of projects as well as the quality and safety of tunnel construction.

Its frozen cutter head enables the formation of a 'frozen disk' around the head, which helps wall off the cutter head from underground water and increases the strength and stability of soil, making it possible and safe to replace cutters under the protection of frozen soil.

Compared with commonly used techniques such as cabin-opening via air pressure adjustments and normal air pressure cutter heads, this technique is safer and more reliable and widely applicable. It can help cut costs and ensure timely construction.

The machine's composite grouting system can safeguard construction under different circumstances, especially under complicated strata conditions where the upper part is soft and the lower part is hard. It can help resolve subsidence control issues when a shield machine passes through buildings, railways, pipelines, rivers, lakes or seas.

CRHS' heavy machinery base can supply quality products and services to underground construction projects in the area around the mouth of the Pearl River and in southern China and can aid infrastructure construction in countries along the One Belt, One Road route, a company representative told Yicai Global.

Established last year, CRHS' heavy machinery base has passed acceptance procedures. The group plans to make 50 shield machines with diameters of up to 18 meters annually, making the largest such machines in China and some of the biggest in the world.