Recently, at the estuary of the Yangtze River, the world’s largest-diameter vertical shaft boring machine, “CREC Qiming”, was successfully launched from Shaft No. 2 of the Chongtai Yangtze River Tunnel, while nearby the world’s largest-diameter high-speed railway shield machine, “CREC Linghang”, has already advanced more than 10 kilometers—one horizontal and one vertical unit advancing in coordinated breakthroughs. In the Guangdong–Hong Kong–Macao Greater Bay Area, the world’s first in-situ variable-diameter shield machine, “?CREC Bianjing No. 1”, is tunneling efficiently on a Guangzhou Metro project. At the Hangzhou Gaojiao Road Tunnel, “CREC Yuhang”, with an excavation diameter of 16.2 meters, was successfully launched. Meanwhile, China’s first vertical large model dedicated to tunnels and underground space, along with the Pioneer Industrial Manufacturing Large Model, has been successively released. Through continuous technological breakthroughs and a series of major national engineering tools, CREC has persistently expanded the boundaries of domestically developed shield technology, making Chinese shield machines an ever more brilliant national calling card.
In recent years, with the in-depth advancement of national strategies such as deep-earth development and building a strong transportation system, the demand for space underground and resources from the deep subsurface has become increasingly urgent, placing higher requirements on the technical performance, application adaptability, and service capabilities of high-end tunneling equipment. Anchored in strategic needs, CREC has continuously deepened the construction of a full-chain shield tunneling service system, forming a complete industrial chain encompassing core technology R&D, customized manufacturing, precision construction and operation, and green equipment remanufacturing. This enables the provision of full life-cycle solutions tailored to different geological conditions and operating scenarios, comprehensively meeting diversified and personalized customer needs. At the same time, application boundaries for tunneling machines continue to expand—from rail transit to water conservancy and hydropower, from mineral extraction to pumped-storage projects—forming a full product matrix covering multiple sectors and scenarios.
Strategic Guidance: Practicing the “Three Transformations” to Achieve Leapfrog Development
On May 10, 2014, during an inspection of the shield machine final assembly workshop of China Railway Engineering Equipment Group, a subsidiary of China Railway Hi-Tech Industry, President?Xi Jinping made the important instruction to: promote the transformation of Chinese manufacturing toward Chinese creation, Chinese speed toward Chinese quality, and Chinese products toward Chinese brands. This guidance has served as a beacon lighting the path forward, not only setting the course for the transformation and upgrading of China’s manufacturing industry, but also igniting the ambition of Chinese brands to go global.
As the birthplace of the “Three Transformations” directive and the origin of China Brand Day, CREC has consistently borne this mission in mind and put it into practice. In the field of tunneling equipment, it has continuously broken through technological barriers and reset industry benchmarks, advancing the equipment manufacturing sector toward high-end, green, and integrated development. Through a succession of world-first and domestically pioneering?tunneling machines, CREC has written a magnificent chapter of China’s high-end manufacturing—from nothing to something, from good to strong, and from rooting itself in China to competing across the globe. Guided by the spirit of the “Three Transformations,” Chinese shield machines have achieved a leap from following to comprehensive global leadership.
Breaking the Deadlock: From Zero to One—Building China’s Own Shield Machines
Looking back at the development of CREC shield machines reveals a 25-year journey of self-reliance and perseverance. In 1997, during construction of the Qinling Tunnel on the Xian-Ankang Railway, a German tunneling machine was introduced for the first time. While efficiency improved significantly, the project faced high equipment costs, no bargaining power, and inadequate service. The harsh reality that without core technologies, there is no voice?profoundly impacted CREC professionals and solidified the original aspiration to build shield machines of our own.
In 2001, shield machine development was included in China’s “863 Program.” CREC established the country’s first industrialized shield machine base, assembling a dream team of 18 core engineers to embark on R&D from scratch. In 2008, China’s first composite earth-pressure-balance shield machine with independent intellectual property rights, “CREC No. 1” was successfully rolled off the line, completely breaking technological monopolies and achieving a historic breakthrough from zero to one.
Innovation-Driven Growth: From One to Many in Forging Major National Engineering Tools
Focused on major national strategic needs, CREC has successively overcome key technologies in shield design and manufacturing under ultra-large diameters, ultra-small diameters, and extreme working conditions. A series of world-first and domestically pioneering products representing the industry’s advanced level have emerged, including the world’s first horseshoe-shaped shield machine “CREC Menghua”, the ultra-large-diameter slurry shield “CREC Chunfeng”, the world’s largest-diameter hard-rock TBM “CREC Caucasus”, China’s first large-inclination shaft TBM “CREC Yongning”, the world’s largest-diameter high-speed railway shield “CREC Linghang”, and the world’s first in-situ continuous large-diameter variable shield “CREC Bianjing No. 1”. These innovations have won major awards such as the First and Second Prizes of the National Science and Technology Progress Award, the Gold Award of China Excellent Industrial Design, and the China Patent Gold Award.
At high-altitude and cold-region project sites, six TBMs led by the domestically developed “CREC Snowland Pioneer”, China’s first large-diameter hard-rock TBM for plateau and cold environments, are advancing powerfully, laying the foundation for a sky road linking the plateau with inland regions. Deep in the Tianshan Mountains, two TBMs—”CREC Ping’an”?and “CREC Green”—support construction of the Guozigou pipeline tunnel for the West–East Gas Pipeline Phases II and III, ensuring smooth operation of this energy artery. In water diversion projects, the Central Yunnan Water Diversion Project has deployed five TBMs/shield machines including “CREC Hongyi”?and “CREC Yunling”, with total excavation nearing 57 kilometers. The South-to-North Water Diversion Project?employs six 12-meter-class ultra-large-diameter TBMs such as“CREC?Jianghan Pioneer”?and “CREC Jianghan Ping’an”, closely linking the Three Gorges Project with the South-to-North Water Diversion—two major national projects. The Pearl River Delta Water Resources Allocation Project has mobilized 29 shield machines including “CREC Yuehai No. 1”?to build a water security system for the Greater Bay Area. In pumped-storage hydropower, CREC has provided equipment for more than 40 projects nationwide; successful applications of machines such as the ultra-small turning-radius TBM “CREC Wendeng”?and the inclined-shaft TBM “CREC Yongning”?have shortened schedules and reduced ecological impacts, accelerating the development of green energy. In mining, the “CREC Longyuan”?hard-rock TBM at the Dazhonghe Lithium Mine in Hunan achieved monthly advances exceeding 1,000 meters for three consecutive months, setting a world record; at Shandong Laizhou Ruihai Mining, the “CREC Haiyue No. 1”?and “CREC Haiyue No. 2”?TBMs filled a domestic gap in deep-buried metal mine excavation technology.
Accelerating the Leap: Building National Platforms to Overcome Key Technological Bottlenecks
Looking back, tunnel construction in China during the 1980s and 1990s was constrained by manual labor and traditional machinery, with workers operating in high-risk environments prone to collapses and water inrushes. Although foreign shield machines were technologically advanced, they often proved ill-suited to local conditions, leaving China in a passive position of high-cost imports, limited autonomy, and constrained maintenance—turning dependence on key technologies into a chokepoint for industry development.
Against this backdrop, China Railway Tunnel Group took the lead, together with China Railway Engineering Equipment Group and Zhengzhou University, to establish the National Key Laboratory for Tunnel Boring Machines and Intelligent Operation & Maintenance. As the only national public research platform in this field, the laboratory is dedicated to breaking through key bottlenecks in core tunneling equipment technologies and intelligent O&M systems, driving the intelligent transformation of underground engineering construction through independent innovation. Born for tunnels and established for the nation, the laboratory has, since its inception, taken breaking monopolies and leading the industry as its mission, achieving continuous innovation and frequent breakthroughs.
In 2017, the laboratory built the industry’s first TBM engineering big data platform, shifting tunneling operations from experience-driven to data-driven and winning the Special Prize for Practical Technology of CREC. In 2022, it pioneered intelligent control of large-diameter shield tunneling and integrated intelligent assembly of internal tunnel structures, successfully applied to the Shanghai Airport Link project to achieve unmanned intelligent construction and efficiently promote innovation and value creation in major projects. In 2024, it overcame key technologies for intelligent slurry shield tunneling with multi-system coordination, developed an intelligent control platform, and successfully applied it to the Chongtai Yangtze River Tunnel, establishing nine intelligent construction technology systems and releasing the Blue Book on Intelligent Construction of China’s Shield/TBM Tunnels, providing a technical paradigm for the industry. In 2025, the intelligent construction cloud center for tunneling machines was completed, and the first vertical large model in the tunnel and underground space field—Pioneer Tunnel Large Model V1.0—was released, enabling full-process intelligent empowerment in geological perception, tunneling decision-making, and risk early warning.
Enhancing Quality and Speed: Digital Intelligence Empowering a New Construction Paradigm
Intelligent construction of shield tunnels represents an industry-wide restructuring centered on data-driven methodologies. By collecting, governing, and integrating full life-cycle data of tunnel construction, key technologies such as intelligent tunneling, automated assembly, and coordinated control are overcome, enabling dynamic tracking throughout the project lifecycle, real-time risk prevention, and autonomous, efficient equipment operation. This shifts underground engineering from experience dependence to data-driven decision-making, upgrading from labor-intensive methods to intelligent manufacturing and fundamentally reshaping the logic of tunnel construction.
In 2021, a major breakthrough in core technologies led to the debut of the TBM intelligent tunneling system, enabling five core functions—cloud-based self-prediction of tunneling parameters, automatic attitude cruising, adaptive chamber pressure, self-adjusting muck discharge, and automatic anomaly cutoff—laying a solid technological foundation for intelligent construction.
In 2022, Intelligent Shield Tunnel Construction V1.0 was successfully demonstrated on Lot 11 of the Shanghai Airport Link project by China Railway Tunnel Group, achieving for the first time the engineering application of manned supervision with unmanned operation in shield tunneling. Five achievements—intelligent tunneling, intelligent assembly, intelligent coordination, intelligent diagnosis, and intelligent inspection—worked in synergy, marking China’s formal entry into a new era of intelligent tunnel construction.
In 2024, Intelligent Shield Tunnel Construction V2.0 was successfully demonstrated on the Chongtai Yangtze River Tunnel project by China Railway Tunnel Group, achieving intelligent tunneling under full-system algorithmic control for the first time. A comprehensive intelligent management system covering the entire construction chain was established through nine intelligent achievements—intelligent sensing, intelligent design, intelligent prefabrication, intelligent tunneling, intelligent installation, intelligent structuring, intelligent environmental control, intelligent transportation, and intelligent management—setting new global records with a peak monthly advance of 718 meters and an average of 600 meters, pushing efficiency and precision to the world’s highest level.
Since the launch of R&D efforts in 2010, China’s intelligent shield tunnel construction has progressed through three stages—key technology breakthroughs, engineering big data platform development, and deep data empowerment—achieving a leap from V1.0 to V2.0. It is now accelerating toward the higher dimension of V3.0, with each breakthrough marking new global heights in intelligent tunnel construction.
Leading the World: From Excellence to Distinction Among the Global Top Tier
In 2012, domestically produced shield machines were exported to Malaysia. At the outset, overseas markets generally lacked confidence in Chinese-made equipment. Ultimately, CREC-built shield machines, with outstanding performance, achieved a maximum daily advance of 21 meters and completed tunneling 43 days ahead of schedule, setting a new Malaysian record and leaving foreign competitors far behind. In 2018, two small-diameter hard-rock TBMs customized for the Greater Beirut Water Supply Project in Lebanon completed tunneling ahead of schedule, helping solve water shortages for 1.6 million residents. In 2019, two large-diameter earth-pressure-balance shield machines for Paris Metro Line 16 rolled off the line, marking Chinese shield machines’ entry into the global high-end market. In 2023, the world’s first green shield machine, “CREC No. 1237”, made a high-profile debut and was deployed to Sicily, Italy, to support high-speed railway tunnel construction. In 2025, two newly developed 15.7-meter ultra-large-diameter shield machines set a new record for China’s overseas exports of shield equipment.
As there is a saying in China: Ascending to the sky is the Shenzhou spacecraft, diving into the deep sea is the Jiaolong submersible, and tunneling underground is the TBM. Today, seven out of every ten shield machines worldwide come from China. As the leading enterprise in China’s shield tunneling sector, CREC has delivered more than 1,700 shield machines, exported to over 30 countries and regions across six continents. Chinese shield machines have become true “pride-makers” and a calling card for China’s high-end equipment going global. To date, CREC shield machines have completed more than 5,000 kilometers of tunneling and, with their outstanding performance and safety, have become the preferred equipment for tunnel construction both at home and abroad.
The leap of Chinese shield machines from followers, to peers, to leaders is not only a chronicle of progress in equipment manufacturing, but also a triumphant anthem of self-reliance and pioneering spirit among CREC’s shield professionals. The persistence in innovation and resilience shown by CREC shield teams in adapting to change shines like a beam of light along the tunneling path. Looking ahead, CREC shield machines will continue to push new technological heights with smarter designs, superior performance, and greener concepts. This steel armadillo?will keep piercing mountains and seas, traversing the underground with the wisdom and resilience of Chinese manufacturing, and writing an even more magnificent chapter in global connectivity.
