Core Viewpoint - The article highlights the critical maintenance work conducted by the Fuzhou Power Supply Section of the Nanchang Railway Bureau, focusing on the safety measures and operational challenges faced by the contact network workers in the Qingyun Mountain Tunnel, which is a vital part of the Changfu Railway. Group 1: Operational Details - The Qingyun Mountain Tunnel, known as "the first tunnel in East China," spans approximately 22 kilometers and accommodates over 60 trains daily [1] - Workers are equipped with oxygen tanks and gas masks due to the risks of oxygen deficiency and toxic gas accumulation in the tunnel [3] - The maintenance work includes cleaning the contact network insulators, which can accumulate dust and coal particles, potentially leading to operational hazards [5] Group 2: Safety Measures - The workers conduct safety checks using carbon monoxide detectors to ensure a safe working environment before commencing operations [1] - The cleaning process involves high-pressure water guns and manual scrubbing to remove stubborn dirt from insulators, highlighting the physical demands of the job [5] - The team operates during a limited "window" of time when trains are not running, emphasizing the urgency and importance of their work [5]