The heavy freight trains laden with coal start in Watang Town, Xing County, Lyuliang City, Shanxi Province, and end at Rizhao Port in Shandong Province to the east, spanning 1,260 kilometers. It is China's first self-designed and built heavy-load railway with a 30-ton axle weight, and it is also the world's first 1,000-kilometer-plus heavy-load railway completed in one go. This vital railway serves as a key coal transport route connecting East and West China.

　　As the year draws to a close, nearly 1,000 railway workers from CR-Zhengzhou continue to work tirelessly like knights in the Taihang Mountains, safeguarding this crucial lifeline of warmth and energy.

　　"Roller coaster drivers": precision control of heavy freight trains.

　　"Green light, ready to depart," said Wang Lijun, the driver of the G71503 heavy freight train, as it left Changzinan Railway Station early on January 14. The train, filled with coal, was on its way. During the Spring Festival travel season, more than 140 trains depart daily from this station, with one heavy-load train leaving every 10 minutes during peak times.

　　Wang Lijun, 45, is one of the first drivers of the Watang-Rizhao Railway's heavy-load trains. He once drove the first-ever heavy-load train on the line and is a true veteran in the field. The 1,600-meter-long trains he drives are eight times the length of a standard Fuxing EMU train.

　　The trains roar down from the Taihang Mountain top to the North Henan plain, descending 1,100 meters in altitude. The route includes 26 slopes, 24 tunnels, 167 curves and 184 bridges, with some sections having a vertical height difference of about 11 stories between the front and rear of the train. Driving these trains is like navigating a roller coaster, and that is why Wang and his colleagues are known as the "roller coaster drivers."

　　"Climbing uphill isn't scary, but the most difficult part is going downhill. From Changzinan Railway Station to Tangyindong Railway Station, there are 10 critical braking points. Every time we engage the brake, the error must be within 0.2 millimeters to ensure the safety of the train," Wang said. The 190-kilometer stretch between Changzinan Railway Station and Tangyindong Railway Station is a continuous downhill slope, and the pressure difference for braking must not exceed 1000 Pa. The operating handle's scale is as fine as 0.2 millimeters, which is equivalent to the thickness of a hair.

　　A good horse needs a good saddle. Wang Lijun said the key to precise braking is the locomotive he operates. The HXD1 electric locomotive is an advanced eight-axle high-power locomotive in the nation, with a continuous power of 9600 kilowatts, easy to operate, low failure rate and high level of intelligence, making significant contributions to energy transportation.

　　"At the front of Taiqianbei Railway Station, the 71503 train arrives complete." After more than five hours of operation, Wang Lijun successfully brought the train to a stop. "When the train is securely stopped and I finish my shift, that's the most rewarding moment for me," he said.

　　"Little crab": efficient support for train maintenance.

　　On January 13, at the Changzinan Railway station inspection yard, the temperature dropped to -12°C with biting cold winds. Maintenance worker Li Jinyong was using a crowbar to replace the brake pads on a heavy freight train. Due to the frequent braking on the Watang-Rizhao Railway's steep inclines, brake pads wear out quickly. Changzinan Railway Station replaces over 300 brake pads daily.

　　Li's job is to inspect trains through methods such as "look, listen, ask, feel" to ensure their condition is optimal. By the end of the day, he bends down or squats more than 2,000 times, walking nearly 20 kilometers.

　　After replacing the brake pads, Li Jinyong also checks the braking system to ensure it is working well. In the past, inspections were done manually, which was labor-intensive and inefficient. In harsh weather, the difficulty of repairs increased significantly. However, with the introduction of smart inspection robots, things have improved dramatically.

　　Next to Li, a small, square-shaped device resembling a "little crab" swiftly crawls beneath the train. This smart inspection robot, according to Li, equipped with two high-definition cameras, can travel at a speed of up to 30 km/h, automatically collecting high-definition images and sending them to a server. If a fault is detected in the braking system, the robot will notify maintenance workers to perform further checks and repairs.

　　"The 'little crab' can inspect in 5 minutes what would take four workers 20 minutes, and it is unaffected by weather, significantly reducing our workload and increasing the vehicle turnover rate by 20%," Li Jinyong explained.

　　Many other guardians are working tirelessly on the Watang-Rizhao Railway in the cold winter. For example, Wu Zhiheng, a tail-end worker at the western end of Track 16, has just installed the "iron backpack" on the tail of a train and received a call to head for Track 7. His "iron backpack" consists of three tail-end main machines, each weighing 26 kilograms. During the Spring Festival, temperatures can drop below -20°C at Changzinan Railway Station, but Wu has to remove over 20 tail-end machines every shift, often sweating despite the cold.

　　Since the Watang-Rizhao Railway opened on December 30, 2014, it has grown from operating 10 or so trains daily to over 140 trains at full capacity. In 2024, it handled 98.54 million tons of freight, with a cumulative total of 603 million tons of coal and other goods sent.