China Railway Tunnel Group founded in 1978, is the largest engineering enterprise specialized in tunneling and underground works of China, and the backbone member of China Railway Group Limited which is listed in the World Fortune 500. The Group, integrating survey & design, construction, scientific R&D and equipment manufacturer, has always been actively engaged in scientific research, technology breakthrough and new technology promotion and application. . CRTG build the European branch around 2018, now the European HQ is located in Stockholm, Sweden.