In the drizzling rain, humid air, and gloomy weather, a metro train disappeared into a 19-story residential building in Southwest China's Chongqing Municipality. During the rainy season, the metro trains are just like several dragons that serve the daily commuting needs of local residents. Liziba station fascinates every tourist and has become a symbolic attraction in Chongqing.

Chongqing's mass transit system has always set the internet ablaze. A video showing a train passing through a 19-story residential building went viral on the internet, notably on the TikTok app, which is also known as Douyinin China.

There is a group of engineers, just like "dragon-trainers," who maintain the metro trains on a daily basis. Zhang Jie, 46 years old, is one of them.

As a lead engineer at Monorail Zhang Jie workshop, his main work is metro train maintenance and related technological innovation.

Since the metro's construction, Zhang Jie and his crew, like the bone of the city, have been guarding the transit system of Chongqing like watchmen.

Standing in front of the platform in his workshop, Zhang Jie is watching the metro train heading to next station. Photo: Lin Luwen/GT

Nocturnal work

Hitching a ride in a residential building is rooted in Chongqing residents' daily lives. However, the smooth transit system can't operate without maintenance. Zhang is one of the engineers who takes care of the "city-conveyor."

To keep a metro train from breaking down during day time, Zhang and his colleagues armed with white gloves and head lamps will check every component on the metro trains at night. The maintenance work requires not only working at midnight but also within a deadline. Zhang's crew is trained to complete their inspections in two to three hours.

"Minutes and seconds have become the most important guideline for us," Zhang said.

"The metro trains operate 10,000 times per month," Zhang said with no hesitation. To keep every journey safe and sound, he recites the exact statistics and the core experimental data.

"No train breakdown is my biggest safety target," Zhang said.

A sense of responsibility towards monorail grows with Zhang's work experience. Zhang takes his monorail career as a lifelong pursuit.Working on the special night shift with the hustle and bustle has brought Zhang a special connection with the straddle monorail.

"The straddle monorail is my conviction," Zhang told the Global Times.

Like all frontline workers, when talking about his family, his 15-year-old daughter became his Achilles' armor as well as the heel.

"My daughter always thinks of me when taking the metro to school and back home," Zhang said. "The support from my family helps keep me work with enthusiasm."

From zero to hero



However, the legendary metro train was built upon doubt. Chongqing is known as the "mountain city" with limited transport space, building a metro system in the city was considered an impossible feat by many experts.

The city planners drew eyes on the monorail technology that has been applied in Japan as a solution for an essential metro train route with low-noise, low-vibration and high-gradeability, which caters perfectly to Chongqing's terrain. 

Zhang told the Global Times that most of metro trains' noise comes from the engine, and by using electric engines, the noise can be drastically reduced.

To develop their rail transit system, Chongqing imported straddle monorail technology from Japan in 1998 and completed the first metro line, Metro Line 2, in 2004.

However, importing foreign technology means extremely high maintenance costs. The rail infrastructure is doomed to be nationalized.

The uncharted exploit brings a huge challenge to Chonging as well as Zhang Jie.

As a frontline worker, he did experience the challenges brought by the technological blockage and has realized the importance of nationalization.

"It's impossible to get the original engineering drawings of the train from Japan," Zhang told the Global Times. In the beginning, Zhang and his colleagues only had one photo to use as a reference when fixing a device.

Zhang decided to find an appropriate material to replicate a high-cost imported switch to reduce maintenance costs.

After a four-month investigation of over 100 suppliers, a small company shed light on a possible material to make the switch. The challenge came right away to test the right formula of additives that needed to be added to the material. Zhang spent another four months devoting himself to countless experiments.

Eventually, the material that was applied to the switch has declined the fault rate by 49 percent, and prolongs the switch's longevity from five years to eight years. Zhang told the Global Times that the new material has been applied to the second-generation monorail.

After over 10 years of research and development, Zhang now owns his workshop, which is supported by the Chongqing Municipal Human Resources and Social Security Bureau. However, he didn't take it all for granted.

"It's a workshop for all of us," Zhang said.

As a deputy of the 13th National People's Congress, chief of the Zhang Jie Workshop, and an engineer with a lot of experience, Zhang tries to be a voice for the grassroots workers.

"I know what workers want because I'm one of them," Zhang said.

Stay open-minded

Despite the barriers he may encounter along the road to nationalization, reform and opening-up is deeply rooted in Zhang's mind. He appreciates Japan for offering the straddle monorail patent to China.

"Seeing is the first thing," Zhang said. He added that seeing a new thing is the mother of innovation.

"Only by importing techniques from other countries can provoke new inspiration and thoughts in China," Zhang told the Global Times.

Zhang was a judge and guest speaker at the Belt and Road International Skills Competition that was held in Chongqing in May. 

"The Belt and Road spirit has brought innovation to workers in a skilled field as well," Zhang said. 

According to a research report on the development of Monorail Traffic in China released in March, Chongqing's monorail is the world's longest monorail, and has a daily passenger flow of 1.08 million and the total operating mileage from Line 2 and Line 3 reached 98.45 kilometers. 

In the overseas market, Chongqing's metro employees have participated in rail transit construction projects in Indonesia, Brazil and Thailand.

"I wish cities like Chongqing that are along the Belt and Road can develop a monorail as well," Zhang said.