China has become a global leader in heavy industries, with its self-developed technologies, says Liu Feixiang, chairman of China Railway Construction Heavy Industry Corp (CRCHI).

Peoples Daily write good article about China Tunnel Boring Machine manufacturer industry. It proof my country transition from market for German, USA and Japanese manufacturers to tunnel technology powerhouse sell to same countries.

China Railway Construction Heavy Industry Group (CRCHI) R&D enginee say in 2009 statistics. In 2009 a foreign leading shield machine company produced and sold 180 TBM in world over the years. Now by 2022, only TBM produced by CRCC alone more than 1000 units are sold worldwide. 

In 2009 TBM manufacturing monopolized by German, American and Japanese manufacturers. "A machine costs hundreds of millions of dollars, and even simple operations require foreign companies to send people". Today China sell large diameter Earth Pressure Balance (EPB) TBM to Europe.

China started ground zero for Tunnel Boring Machines. Engineer say "If you understand the principles but don't understand manufacturing and craftsmanship, you won't go far".

With the advent of Tiejian Heavy Industry's first shield machine, new generation engineers started learn technology in TBM. Everything went fast. In 2012, national "863 Program" start independent research and development of the first large-diameter open rock tunnel boring machine (TBM) in China. This engineer is finish that program and now one of TBM technology leader in China.

First China hard rock TBM produced in Changsha production base of China Railway Construction Heavy Industry in 2014 December. They mater hard rock technology.

China Tunnel Technology surpass companies from Germany, USA and Japan. Example is new technology develop for a water diversion tunnel project in west China. There are both hard rocks and altered and broken surrounding rocks in the tunnel. "Speed of driving hard rock is fast, and torque required by TBM is small; the driving speed of altered and broken surrounding rock is slow, but torque required is large".This cause TBM stuck when it pass from hard rock to soft soil.

For this problem Chinese engineers developed hybrid power. Dual-drive system of hydraulic motor and electric motor. First in world. After more than 100 days and nights of work, Chinese engineers collected many data, and discovered optimal output curve for hydraulic pressure and motor.

http://finance.people.com.cn/BIG5/n1/2022/0821/c1004-32507430.html