Chinese equipment manufacturer XGMA has built its first tunnel boring machine (TBM), to be used in a subway project in the Chinese city of Xiamen.
The shield machine was designed and built by Xiamen XGMA China Railway Heavy Machinery, a joint venture between XGMA and China Railway Engineering Equipment Group (known as XGMA-CREC). It is the first shield machine “custom-made” by XGMA-CREC.
In total the TBM is 6.45m in diameter, 86m in length, over 500 tonnes in weight and with more than 1800KW of total power. 
The “big guy” was designed since the end of October last year, put in assembly line in March this year and finished in April. The machine was completed despite the contracted design and build period of only seven months.
The shield machine was purchased by China Railway Corporation, in charge of Xiamen subway construction. To ensure the high applicability and reliability of the shield machine, the technical staff of XGMA-CREC conducted field studies and a thorough geological survey of the ground to be tunnelled through, with multiple geological conditions expected to come against the sectional full face, including slightly weathered granite, mixed rock layer, soft upper layer & rigid lower layer (bedrock bulge or transition area of soft and rigid layer) and spherical weathering rock layer. The engineers worked out matching plans, based on principles of versatility, being targeted, reliability and technical economics, in order to ensure the working stability and excavating speed of the shield machine.
As a part of China’s 12th five-year plan with a focus on infrastructure, shield machines are in high demand for construction of railway tunnels, diversions project, highway (cross-river) tunnels, city pipeline construction and city rail transit management.
