At an elevation of 4,500 meters, the Nagchu railway workshop on the Qinghai-Xizang Railway exemplifies the physical challenges faced by workers on the world’s highest rail line. The workshop’s short staircase, colloquially known as the “deadly 23 steps,” highlights the toll that high altitude takes on employees tasked with maintaining critical infrastructure in the region.

Located on the Northern Xizang Plateau, much of the railway operates above 4,000 meters, where oxygen levels fall to about 60 percent of those at sea level. Workers often contend with thin air, sub-zero temperatures, strong winds, and significant geographic isolation. These conditions make routine maintenance physically demanding, with even a brief climb leaving workers breathless and fatigued. Zhang Huxiong, a railway maintenance worker, described how carrying tools after hours of outdoor labor in these conditions often resulted in severe breathlessness and blue lips caused by hypoxia.

Historically, the harsh environment demanded exceptional endurance from workers. Gu Haidong, who has maintained tracks in the Guanjiao Mountains near the plateau’s gateway since 1994, recounted the difficulties of early maintenance efforts. During that period, the railway ran over exposed mountain passes, requiring lengthy, strenuous work in unpredictable alpine weather. Gu recalled that, at times, he was away from his family for nearly 100 days in a row, with long journeys home that often took an entire day.

The opening of the New Guanjiao Tunnel in 2014 marked a turning point for both railway operations and workers. This 32.69-kilometer dual-track tunnel, the world’s longest high-altitude railway tunnel, drastically reduced transit times through the mountain pass from two hours to 20 minutes. For workers like Gu, the trip home shortened significantly, improving quality of life.

Technological advancements have also transformed how the railway’s challenges are managed. According to China State Railway Group, modern facilities at high-altitude signal and maintenance sites now include enhanced oxygen supplies, improved water and sewage systems, internet access, and recreational amenities. Most notably, automation and remote monitoring have reduced the necessity for workers to spend extended periods outdoors in harsh conditions.

Zhang noted that upgraded signaling systems allow many devices to be monitored indoors, with track switches controlled remotely, minimizing exposure to the elements. For train operations, these improvements add critical layers of safety.

A new generation of workers is adapting to the increasingly high-tech environment. Hao Bin, who relocated from Inner Mongolia to the Guanjiao Tunnel sector, described how modern inspections use automated trolleys equipped with sensors that collect track data in real time. This technology enables early detection of potential issues before they escalate into serious problems.

Despite technological progress, manual intervention remains essential when maintenance is required. Workers still face the demanding physical conditions of the plateau, stepping outside into the cold, thin air to address warnings detected by automated systems.

At Nagchu, the “deadly 23 steps” continue to serve as a stark reminder of the challenging environment where modern infrastructure meets human endurance.