"The spirit of model workers—dedication to work, striving for excellence, hard struggle, courage to innovate, indifference to fame and fortune, and willingness to contribute; the spirit of labor—respecting labor, loving labor, working hard, and honest labor; the spirit of craftsmen—persistent focus, striving for perfection, meticulousness, and pursuit of excellence... are powerful spiritual motivations that inspire the entire Party and people of all ethnic groups across the country to advance bravely regardless of obstacles."

At CRCHI,

there is also a group of outstanding model workers and advanced individuals,

who strive on the front lines of production and R&D,

creating extraordinary achievements through ordinary labor,

and interpreting the spirit of model workers and craftsmen through practical actions.

In May, the CRCHI Trade Union held

the "Chinese Dream · Beauty of Labor · Model Workers Advanced Publicity Month" event,

to help everyone learn about some of these advanced representatives,

and feel the inspiring stories of model workers.

In this issue, we share the story of Zhang Shuaikun, Deputy Director of the Tunneling Machine Research and Design Institute of the R&D and Operation System at CRCHI, recipient of the All-China Federation of Railway Workers' Unions' "Locomotive Medal," one of the first "Huxiang Craftsmen," holder of the Changsha High-level Talent Green Card, and winner of the first national "Shield Tunneling Craftsman" award.

Zhang Shuaikun: Breaking Foreign Technology Monopoly and Winning Dignity for Made in China

"With a maximum excavation diameter of 16.07 meters, it is not only huge but also powerful." Talking about the "Jinghua," Zhang Shuaikun, Deputy Director of the Tunneling Machine Research and Design Institute at CRCHI, was all smiles. "This is the first time a Chinese enterprise has successfully achieved industrial manufacturing of a 16-meter-class ultra-large-diameter shield tunneling machine. The development and application of this equipment have strongly consolidated the independent controllability of core technologies for domestic ultra-large-diameter shield tunneling machines."

At CRCHI, Zhang Shuaikun has participated in the development of more than just the "Jinghua." "Yuan'an," "Zhenxing," "Xingsheng"... Since joining CRCHI in 2010, for 12 years, Zhang Shuaikun has devoted himself to one thing—developing slurry shield tunneling machines.

Starting from the "Heart," Pursuing Dreams

In 2008, after graduating from university, Zhang Shuaikun entered the shield tunneling machine industry, mainly engaged in equipment use and supervision. At that time, all shield tunneling machines used in domestic construction relied on imports. Through his work, Zhang Shuaikun gradually discovered that imported equipment was not only expensive, had long production cycles, and lacked timely spare parts and services, but also suffered from "acclimatization" issues.

"In China, geological conditions vary greatly from region to region, and each shield tunneling machine must be tailor-made. However, R&D personnel from foreign shield tunneling machine manufacturers rarely come to domestic construction sites for on-site inspections; they only draw on experience from similar strata in the past. Once geological inadaptability occurs, it will bring huge safety risks and unpredictable economic losses." In view of this situation, Zhang Shuaikun resolved to develop China's own shield tunneling machines.

Because of his love for design and to realize the dream of developing domestic shield tunneling machines, in 2010, Zhang Shuaikun joined CRCHI and, together with his team, started from scratch, working hard to independently develop slurry shield tunneling machines, embarking on his journey of pursuing dreams.

Breaking Foreign Technology Monopoly and Winning Dignity for Made in China

Zhang Shuaikun rarely has time to spend with his parents, wife, and daughter; he is either working overtime or on business trips, completing one R&D project after another with persistence, effort, and sweat.

In 2013, Zhang Shuaikun led his team to successfully develop the first domestic 6-meter-class composite slurry shield tunneling machine, achieving the first crossing of the Hun River by a domestic shield tunneling machine.

In 2014, construction began on the section of Lanzhou Metro Line 1 crossing the Yellow River, with the crossing stratum being water-rich full-face cobble stratum. Zhang Shuaikun led his team to break through multiple core technologies, achieving the first crossing of the Yellow River by a domestic shield tunneling machine. During the four crossings of the Yellow River, they solved the worldwide problem of constructing slurry shield tunneling machines in full-face large-diameter cobble strata.

In 2016, the first domestic high-speed railway large-diameter slurry shield tunneling machine "Wangjing" and the first domestic railway double-track ultra-large-diameter slurry shield tunneling machine "Zhongyuan No. 1" rolled off the production line simultaneously, ending the dominance of "foreign shield tunneling machines" in the field of large-diameter slurry shield tunneling machine construction.

In the early hours of February 14, 2018, just two days before Chinese New Year's Eve, at the construction site of the Yuanjiang River Tunnel Project in Changde, Hunan, while replacing the 14th cutter, the gate had been closed and the cutter was about to be pulled out when suddenly mud gushed out, with slurry at nearly 30 meters of water head pressure spraying into the cutterhead chamber. The cutter replacement work stopped. To ensure absolute safety of personnel, Zhang Shuaikun, despite his daughter having just been born, received a call at 1 a.m. and immediately rushed from Changsha to Changde with team members to find the problem...

It is precisely with this dedicated work attitude that in September 2017, the first domestic atmospheric cutter replacement large-diameter slurry shield tunneling machine "Yuan'an," with completely independent intellectual property rights, successfully passed acceptance and rolled off the line in Changsha. The birth of this equipment filled the gap in the field of atmospheric cutter replacement technology for domestic shield tunneling machines. Previously, atmospheric cutter replacement slurry shield tunneling machines were monopolized by foreign countries. Zhang Shuaikun led his team to break the foreign technology monopoly and win dignity for Made in China.

Devoting to Research and Forging National Glory

Before the advent of the "Jinghua," domestic shield tunneling machines with conventional diameters of 6-8 meters and large diameters of 8-15 meters had achieved rapid development, realizing the leap from import substitution to export of domestic equipment.

Zhang Shuaikun admitted that compared with conventional-diameter and large-diameter shield tunneling machines, ultra-large-diameter shield tunneling machines of 15 meters and above have more complex system integration, more difficult processing and manufacturing, higher reliability requirements, and greater engineering application risks, and have always been a weak area in the R&D and promotion of domestic shield tunneling machine technology.

Starting from February 2020, Zhang Shuaikun led his team to tackle key problems and overcome difficulties. At that time, the COVID-19 pandemic broke out, but R&D and design could not be delayed for a single day. Face-to-face communication with customers was almost impossible, so the R&D team could only discuss and confirm various parameters of the shield tunneling machine with customers through video conferences. Generally, the production cycle of an ultra-large-diameter shield tunneling machine is more than 12 months, but under the background of normalized pandemic prevention and control, the R&D team accelerated design and demonstration, and the production workshop worked overtime. The "Jinghua" took only 7 months.

Although the R&D cycle was shortened, the technological content and quality of the "Jinghua" were not compromised at all, making it the culmination of CRCHI's ultra-large-diameter shield tunneling machine technology. Zhang Shuaikun proudly said that the "Jinghua" is the largest-diameter domestic shield tunneling machine in scale and is also at the world's leading level in technological application.

Devotion to research lights up the highlight moment. The "Jinghua" was selected into the book "Questions and Answers on Xi Jinping Thought on Socialism with Chinese Characteristics for a New Era" and appeared at the National "13th Five-Year Plan" Science and Technology Innovation Achievement Exhibition, where it was inspected by Party and state leaders, becoming a well-deserved "internet-famous" heavy equipment. These have greatly encouraged Zhang Shuaikun and his R&D team.

Endless Striving, "Tunneling" Never Stops

During his 12 years at CRCHI, as a design leader, Zhang Shuaikun has participated in major projects such as the Hunan Provincial Major Science and Technology Special Project "Development and Application of Ultra-large-diameter Tunneling Equipment" and the National 863 Program "Research and Application of Key Technologies for Ultra-large-diameter Slurry Shield." Up to now, he has led the development of more than 20 large-diameter shield tunneling machines with diameters above 10 meters, 11 with diameters above 14 meters, and exported to countries such as South Korea and India.

While devoting himself to technology research and product development, Zhang Shuaikun, keeping pace with the rapid development of the enterprise, always maintains the pure heart of constantly surpassing himself and daring to pursue dreams, building national heavy equipment and making domestic shield tunneling machines increasingly powerful. Only because here, "tunneling" victory is at the right time!

Greatness comes from the ordinary, and the ordinary creates greatness.

Let us learn from the advanced model workers

always firm up confidence and maintain drive,

carry forward the spirit of labor, overcome difficulties and obstacles,

continue to write extraordinary stories in ordinary positions,

with our own hard work,

contribute more strength to enterprise development,

and contribute our own beauty of labor to the Chinese Dream!