On the 26th, the world's first carbon fiber subway train for commercial operation, "CETROVO1.0 Carbon Star Express," was officially launched in Qingdao. This car reduces weight by 11% compared to traditional subway vehicles and will lead subway trains to achieve a brand new green upgrade. The vehicle was developed by CRRC Qingdao Sifang Locomotive and Rolling Stock Co., Ltd. (hereinafter referred to as "CRRC Sifang Co., Ltd.") in collaboration with Qingdao Metro Group. At present, the train has completed the factory type test and according to the plan, it will be put into passenger demonstration operation on Qingdao Metro Line 1 within the year. Liu Jinzhu, the chief designer of the carbon fiber subway train at CRRC Sifang Co., Ltd., introduced that the main load-bearing structures of the vehicle, such as the body and steering frame, are made of carbon fiber composite materials, which have technological advantages such as lighter, more energy-saving, higher strength, stronger environmental adaptability, and lower operating and maintenance costs throughout the entire life cycle. Compared with traditional metal material subway vehicles, carbon fiber subway vehicles have a 25% weight reduction in the body, 50% weight reduction in the bogie frame, and approximately 11% weight reduction in the entire vehicle. The operating energy consumption is reduced by 7%, and each train can reduce carbon dioxide emissions by about 130 tons per year, which is equivalent to planting 101 acres of trees. "We have achieved full process and full chain autonomy in the selection, design, manufacturing, simulation, and testing of carbon fiber composite materials, systematically solving problems such as electromagnetic compatibility, sound insulation, and thermal insulation. We have constructed a rail vehicle system solution based on carbon fiber composite materials, effectively reducing train operation energy consumption and wheel rail wear." Liu Jinzhu said. In addition, CRRC Sifang Co., Ltd. has created a carbon fiber train SmartCare intelligent operation and maintenance platform by applying digital twin technology, achieving self inspection and self diagnosis of vehicle safety, structural health, and operational performance. The maintenance cost of the entire lifecycle of the vehicle has been reduced by 22%. Lv Xiaojun, Senior Director Designer of CRRC Sifang Technology Center, introduced that vehicle lightweighting is a key technology for achieving green and low-carbon rail vehicles. Carbon fiber has the advantages of lightweight, high strength, fatigue resistance, corrosion resistance, etc. Its strength is more than 5 times that of steel, but its weight is less than 1/4 of steel, making it an excellent material for lightweight rail vehicles. "The emergence of commercial carbon fiber subway trains marks a revolutionary transformation of the vehicle's main load-bearing structure from metal materials to carbon fiber composite materials." Lv Xiaojun believes that this leap not only breaks through the bottleneck of traditional metal material structures in weight reduction, but also leads China's subway train lightweight technology to a new height, which is of great significance for promoting the green transformation of urban rail transit and helping the industry achieve the "dual carbon" goal. (Lai Xin She)