World's First Carbon Fiber Subway Train Launched in Qingdao
On January 10, 2025, Qingdao Metro Group and CRRC Qingdao Sifang Co., Ltd. (CRRC Sifang) jointly launched the world's first carbon fiber subway train, "CETROVO 1.0 Carbon Star Rapid Transit," on Qingdao Metro Line 1, marking its commercial operation. This innovative achievement not only fills the international gap in the commercial application of carbon fiber composites in the main load-bearing structures of subway cars but also leads the upgrading of China's subway trains towards lightweight and green directions.
The design of the "Carbon Star Rapid Transit" exudes a technological aesthetic, with a color scheme dominated by black, purple, yellow, and blue. The interior of the carriages is equipped with black carbon fiber seats, handrails, and driver's cab consoles. Liu Jinzhu, chief designer at CRRC Sifang, explained that the train's main load-bearing structures, such as the carbody and bogie frame, are made of carbon fiber composites, marking the first commercial passenger application of such materials in subway vehicle primary load-bearing structures globally.
Compared to traditional subways, carbon fiber subway trains offer significant advantages. Firstly, the use of carbon fiber materials makes the train lighter, reducing operational energy consumption. Specifically, the carbody is 25% lighter, the bogie frame is 50% lighter, and the entire train is approximately 11% lighter, resulting in a 7% reduction in operational energy consumption. It is estimated that each train can reduce carbon dioxide emissions by about 130 tons annually, equivalent to planting 101 acres of trees.
In addition to energy-saving benefits, carbon fiber subway trains exhibit enhanced impact resistance, greater fatigue resistance, and a longer structural lifespan. Furthermore, the train incorporates active radial bogie technology, significantly reducing "squealing" when negotiating curves, with a 15 dB decrease in curve passage noise and a 2 dB reduction in interior noise for quieter operation. Due to its lighter weight, the train offers improved vibration damping and isolation, leading to less wheel-rail wear and a 15% or more reduction in wheel-rail forces, significantly decreasing the maintenance requirements for vehicle wheels and tracks.
Notably, the "Carbon Star Rapid Transit" also utilizes digital twin technology to establish a SmartCare intelligent maintenance platform for carbon fiber trains, enabling intelligent detection of faults, intelligent assessment of health status, and optimization of maintenance schedules. By adopting new materials and technologies, the train's lifecycle maintenance costs are reduced by 22%.
The development of the "Carbon Star Rapid Transit" has spanned several years. The project was officially launched in 2021 and completed factory-based type tests and 4,000 kilometers of stability testing in June 2024, followed by its unveiling. From July to December 2024, a six-month field trial was conducted on Qingdao Metro Line 1, involving 20 routine tests and 36 type tests, fully validating the train's performance. On December 21, 2024, the train passed expert reviews for commercial passenger trials, and on January 5, 2025, it passed an independent third-party safety assessment (ISA).
Currently, the "Carbon Star Rapid Transit" is operating with passengers on Qingdao Metro Line 1. Line 1 is a major backbone line in Qingdao's urban rail transit network planning, stretching 60 kilometers with 41 stations and providing interchanges with six other lines. Initially, the "Carbon Star Rapid Transit" will depart from Shanli Station and operate in a shuttle mode between the Shanli and Xingguo Road sections. Subsequent operations will be expanded to cover the entire line based on the performance in the Shanli to Xingguo Road area.
The successful launch of the carbon fiber subway train has not only broken through the bottleneck of weight reduction using traditional metallic materials, achieving an iterative upgrade in China's rail vehicle lightweighting technology, but it will also effectively stimulate the development of the entire carbon fiber composite industry chain, holding great significance for cultivating new productive forces in the rail equipment sector. This innovative achievement undoubtedly sets a new benchmark for Qingdao and the global subway transportation sector.
