Tunnel boring machine 'Caiyun'

The tunnel boring machine (TBM) is known as the "king of engineering machinery" and is a product that gauges a country's manufacturing prowess. With an excavation diameter of 9.03 meters, total length of about 230 meters and overall weight of about 1,900 tons, TBM Caiyun developed by China Railway Engineering Equipment Group Co., Ltd., has been successfully applied in the construction of Gaoligong Mountain Tunnel, a massive project known as the "geological museum" in the history of railway construction. (Photo from China Railway Engineering Equipment Group Co., Ltd., Photo by Liu Can, Hao Luping)