"We must accelerate the cultivation of 'specialized, refined, distinctive and innovative' champion enterprises." The mid-2021 work conference of China Railway Construction Corporation called for continued strengthening of third-tier company development. China Railway 11th Bureau Group No. 3 Company, known as the "Track-Laying Elite Force," is accelerating scientific and technological innovation and digital transformation to build a modernized full-industry-chain track-laying and bridge-erection business. It is a "specialized, refined, distinctive and innovative" advantage enterprise of China Railway Construction Corporation that is presentable, renowned and solid.

　　In the 2020 "Top 20 Third-Tier Companies of China Railway Construction Corporation" list released in the first half of this year, China Railway 11th Bureau Group No. 3 Company has been on the list for 13 consecutive years, and this time it simultaneously made three sub-lists: the Top 20 by Scale, the Top 20 by Efficiency and the Top 10 by Specialization.

　　Scientific and Technological Innovation: Full Mastery of Core Techniques

　　In July this year, at the track-laying site of the Chongqing section of the Zhengzhou–Wanzhou High-Speed Railway, two 500-meter-long rails were slowly laid from a track-laying train stopped on the left line onto the right line through the BLCP500 same-line and adjacent-line long-rail laying unit under the guidance of operators. This scene drew gasps of admiration from on-site observers, who took out their phones to take pictures.

　　"This is the country's first 'track-laying marvel' — the BLCP500 same-line and adjacent-line long-rail laying unit. The track-laying train runs on a single line and can lay long rails on both the current line and the adjacent line, eliminating the time for switching lines and turning back, reducing the number of shunting operations, and greatly improving track-laying efficiency," said Chen Zhongjie, project manager. The cross-line track-laying technology of "running on a single line to lay double lines" fills the gap in China's mechanized cross-line track-laying technology for high-speed railways.

　　On March 7 this year, Guangzhou Metro Line 18, for which the No. 3 Company undertook track-laying across the entire line, successfully completed the step-by-step speed-increase test, reaching a maximum operating speed of 176 km/h, setting a new world record for the fastest metro operating speed and earning the name "underground high-speed railway."

　　"The line adopts the twin-block sleeper monolithic track bed and CRTS III track slab monolithic track bed technologies that are maturely applied in high-speed railway construction, and uses steel-spring floating-slab prefabricated track bed technology for the first time. During construction, self-compacting concrete must be poured on a large scale, which posed a difficult problem for the No. 3 Company, known for track construction," said Zhou Zongmin, project manager.

　　Facing this "hot potato," the project department adhered to the principle of "model guidance, testing first" and developed a "cocktail" admixture compounding scheme. After 23 slab-lifting tests, they successfully "tamed" the self-compacting concrete and set a construction record for pumping concrete over an ultra-long distance of 1.6 kilometers.

　　"As a veteran track-laying and bridge-erection enterprise, we must take scientific and technological innovation as an important support for high-quality development, comprehensively advance breakthroughs in key core technologies, and master the core technologies and processes that lead the track-laying and bridge-erection industry," said Ren Jihong, executive director and general manager of the No. 3 Company.

　　Facing rapidly evolving new technologies, the No. 3 Company continues to challenge key technologies in higher-end fields. It has made breakthroughs in key technologies for bainitic heavy-rail welding and fine adjustment, filling China's technological gap in this field; it has overcome numerous difficulties such as flash-butt welding of grooved rails for the Tianshui tram, the laying of "synthetic resin sleepers" in the sea-crossing section of Xiamen Metro Line 3, and medium- and low-speed maglev railway construction.

　　"Relying on major and difficult projects, we have summarized and distilled a set of key construction technologies, led or participated in the formulation of 23 local and enterprise standards for railways, metros and medium- and low-speed maglev, and achieved a number of scientific and technological results at the international advanced level, such as the laying technology for No. 62 ultra-long large-number high-speed ballastless turnouts. We have publicly published monographs including Railway Engineering Track-Laying and Bridge-Erection Construction Technology and the track volume of the Metro Construction Manual. We have twice exchanged experience on railway engineering line safety management at the construction work conferences of China State Railway Group, and were invited to participate in the High-Speed Railway Construction Organization Management and Technology Forum, where we delivered a report on construction organization technology and management for high-speed railway track engineering," said Wang Jun, deputy general manager and chief engineer of the No. 3 Company. The tree of science and technology has borne abundant fruit, providing strong technical support for the company to build the "Track-Laying Elite Force."

　　Smart Empowerment: Accelerating Digital Application

　　"With the rapid development of industrial digitalization and smart technologies, technological empowerment of infrastructure construction has enormous potential. We must seize this opportunity, closely integrate new technologies with track-laying and bridge-erection, and stay at the forefront of the industry in smart construction," Liu Biping, Party secretary of the No. 3 Company, emphasized repeatedly at various meetings.

　　In the central control room of the Zhengzhou–Wanzhou High-Speed Railway track-laying and bridge-erection base, an operator gently clicked buttons such as "lower, raise, forward, backward" on a mouse through the centralized control system to automatically load a 500-meter-long rail. The whole process took less than five minutes.

　　"At present, domestic construction enterprises mostly use fully manual control for long-rail hoisting. This method requires 32 operators to simultaneously operate gantry cranes for hooking and unhooking-related loading and unloading operations, resulting in high labor costs and high safety risks," Chen Zhongjie said. They innovatively applied "intelligent group hoisting" technology to achieve automated hooking, with one person controlling the group and six assisting, greatly improving rail operation efficiency and automation.

　　The project also took the lead nationwide in trialing intelligent track-marking robots and intelligent track-bolt robots, which can automatically complete the base-color and character marking on rail webs and automatically and precisely position and tighten bolts on rails. "The deployment of these two types of equipment truly realizes unmanned operations," Chen Zhongjie said.

　　The company's self-developed comprehensive track-laying and bridge-erection management and dispatch system has become standard equipment for railway track-laying and bridge-erection and metro track-laying projects, enabling three-level linkage among company headquarters, regional offices and project departments. The system features full video surveillance coverage of track areas, train overspeed alarms, intelligent approval of construction plans, and information data analysis and processing. With network signals covering all railway engineering lines, it has not only won unanimous praise from owners but also attracted peer units to observe and learn.

　　To better align with market development, the No. 3 Company has also optimized and integrated resources to establish a "Digital Research Center" to provide BIM-related technical services and professional guidance for projects; it took the lead nationwide in using and extensively popularizing induction normalizing equipment to replace traditional equipment and comprehensively improve rail welding quality; and the jointly developed new-energy rail welding machine features zero emissions, low noise and high welding efficiency, safeguarding the health of rail welding workers and achieving green construction.

　　One Specialty, Multiple Strengths: Building the Full Track-Laying and Bridge-Erection Industry Chain

　　In recent years, rail-water intermodal transport has opened the "last kilometer" for railways to enter ports and enterprises, and the construction of dedicated lines for local railways, ports and factory and mining enterprises in many provinces across the country has shown explosive growth. The No. 3 Company has successively undertaken operation and maintenance projects for five railways, including the Huangshi New Port freight branch line, the Yichang Ziyun local railway and the Jiangling Power Plant dedicated line, with a total operating mileage of 117.5 kilometers and an annual total freight volume of about 9 million tons.

　　"In just over two years, freight volume exceeded 10 million tons, and we also opened a circular train service from Shawan Station to Zhijiang Station to Dulaying Station (Chengdu Railway Bureau), cumulatively transporting 11,470 containers," said Zhang Zhiyong, project manager, rattling off the operating achievements of the Ziyun Railway operation project.

　　Leveraging its excellent reputation and credibility in the metro track-laying field, the No. 3 Company actively extends the metro industry chain. It not only undertakes specialized construction tasks such as contact rails, evacuation platforms and sound barriers, but also "storms fortresses" in metro maintenance, renovation and dynamic testing, having contracted maintenance and renovation projects for multiple lines in Guangzhou, Hangzhou, Beijing, Nanjing and other cities. It undertook the dynamic testing project for Guiyang Metro Line 1, which has operated safely for more than 1,300 days. Thanks to this, they also won the maintenance task for Guiyang Metro Line 2, in which they participated in construction.

　　In addition, the No. 3 Company has rapidly seized market share in emerging rail transit such as trams and maglev railways, contracting the track-laying tasks for the entire lines of the Tianshui Tram Phase I and Phase II projects, the Changsha Maglev Express and the Guangdong Qingyuan Maglev Tourism Line. They have also taken advantage of the establishment of the East China Company to rapidly expand into water environment treatment, underground utility tunnels, housing construction and other fields, forming scale and achieving notable results in local operations.

　　In April 2021, the China Railway Construction Corporation Track-Laying Technology and Equipment R&D Center was established at China Railway 11th Bureau, undertaking the important task of research on frontier key technologies in the industry, including railway track-laying and bridge-erection technology and urban rail transit track construction technology. The No. 3 Company will take this as a new starting point to fully build a "specialized, refined, distinctive and innovative" "Track-Laying Elite Force."