As a severe cold spell sweeps the nation, coal still forms the bedrock of China's energy security despite the huge progress made in transitioning to renewable energy in recent years.

During peak energy usage, such as when temperatures plummet, coal is still required to plug the gaps in capacity to prevent power shortages.

In North China's Shanxi province, the nation's largest producer of coal, rail shipments have hit a record level.

China State Railway Group's Taiyuan Railway Bureau has ramped up freight train services and enhanced transport efficiency to ensure a steady coal supply during the current cold wave.

To meet demand, railway authorities have deployed the C96 heavy-duty train, a domestically developed model capable of carrying 96 metric tons of coal per car — 16 tons more than previous standard models.

For Wang Hailin, steering a C96 heavy-duty train along the Watang-Rizhao Railway, the job might not involve ferrying passengers, but the weight of his responsibility is just as substantial, as ensuring the vital coal resources reach their destinations efficiently and safely is no small feat.

The Watang-Rizhao Railway stretches 1,269 kilometers from Watang in Lyuliang, Shanxi, to Rizhao in Shandong province, passing through Shanxi, Henan, and Shandong provinces. It interlinks with major rail lines and waterways, providing a crucial route for shipping coal to eastern provinces.

On a chilly morning in November, Wang gently eased the throttle forward, setting the nation's first C96 heavy-duty train in motion from the Houma North locomotive depot in Shanxi, heading east to Shandong.

The increased capacity of the C96 allows for 22 fewer cars in a 10,000-metric-ton train unit, significantly boosting operational efficiency and loading capacity, according to the Houma North locomotive depot.

The introduction of the C96 train, along with an increase in maximum operating speed on the Watang-Rizhao Railway from 80 to 90 kilometers per hour this year, is part of the Taiyuan Railway Bureau's efforts to enhance coal transport capacity. These measures aim to fortify Shanxi's winter coal transportation lifeline and ensure regional energy security.

For drivers like Wang, each technological advancement in train design and operations means higher requirements.

"The C96 train has fewer cars but maintains the same total weight, leading to significant changes in its braking characteristics, which require more precise control over regenerative and dynamic braking force," Wang said, while closely monitoring parameter changes on the control panel and adjusting the throttle.

C96 train drivers and related personnel have undergone training to master new control standards and key parameters such as braking points, pressure reduction levels and the timing for releasing brakes.

The Houma North locomotive depot has also initiated quality enhancement and maintenance programs for each electric locomotive. The safety command center monitors train operations in real-time using data analysis and system alerts to predict potential hazards, such as bearing alarms and surface damage.

According to the Shanxi Henan Shandong Railway Channel Co, the Watang-Rizhao Railway transported 104.37 million tons of coal in 2025, marking a 5.92 percent increase from 2024 and setting a new annual record.

Running parallel to the north of the Watang-Rizhao Railway, the Datong-Qinhuangdao Railway is also operating at full capacity, with daily shipments exceeding 1.2 million tons. This railway extends from Datong in Shanxi to Qinhuangdao in Hebei province, transporting coal for numerous provinces, major power grids and industrial enterprises, accounting for one-fifth of the nation's rail coal transport.

To ensure a steady coal supply, the Taiyuan Railway Bureau acts as a liaison, connecting upstream coal producers with downstream power plants. They keep abreast of coal mine production and power plant needs, devise tailored supply plans for each company, optimize train operations, and establish green channels for coal transport.

At the start of the Datong-Qinhuangdao Railway line, a coal train departs every 13 minutes, and the frequency of 20,000-ton heavy-duty trains is maximized to fully utilize transport capacity.

"In response to the recent temperature drop, we've enhanced communication with governments and businesses to accurately align coal production with transport needs," said Zhao Bowen, a manager at a station of the Taiyuan Railway Bureau."We've also adjusted train schedules to better utilize locomotives and ensure quicker turnaround times between trips."

Hu Changbao, a 20,000-ton heavy-duty train driver along the Datong-Qinhuangdao Railway, said a full heavy-duty train trip from Datong to Qinhuangdao takes about 9 hours and 50 minutes, and if additional time for unloading is included, each trip typically lasts 16 to 17 hours.

"As a front-line coal train driver, I average 7-8 trips per month, with each trip covering approximately 1,300 kilometers," he said. "During the peak coal supply period in winter, the longest driving time in a single day can reach up to 17 hours, and I make 2-3 more trips per month than usual."

The cold winter environment poses challenges for drivers like Hu. During rain and snowy weather, locomotives tend to slide, train components become brittle and braking power decreases, requiring drivers to operate with greater caution to ensure the train's safety and stability.

For these heavy-duty drivers, it is the sense of fulfillment that keeps them committed. "When I see that the coal I transport is ultimately used for heating homes or powering industries, I'm filled with pride," said Hu.

Contact the writers at xunuo@chinadaily.com.cn