China on Thursday unveiled its largest home-made tunnel boring machine and put it into production.

The machine, which has a maximum digging diameter of 16.64 metres, was built in Changsha, capital of central China’s Hunan province.

Jointly developed by China Railway Heavy Industry Corporation Limited and the 14th Company of China National Railway Corporation Limited, the machine is 145 metres long and weighs about 5,000 tonnes. The diameter of its circuit breaker is equivalent to that of a five- or six-storey building.

Zhao Hui, chairman of China Railway Heavy Industry Co Ltd, said the production of the tunnel boring machine marked a breakthrough in the development and production of domestic large-diameter tunnel boring machines in the 16-metre class.

The new machine is expected to be used in the construction of a large-scale tunnel project under the Yangtze River, which aims to create a major cross-river road link under the country’s longest river, connecting Nantong City and Taitang City in East China’s Jiangsu Province.