Core Viewpoint - The article highlights the critical role of the Tianjin Underground Diameter Line in ensuring safe and efficient train operations during the Spring Festival travel rush, emphasizing the dedication of the maintenance team working under challenging conditions to perform essential inspections and repairs [3][4][5]. Group 1: Maintenance Operations - The maintenance team conducts inspections on key electrical equipment, including the contact network and distribution boxes, to ensure the safety of train operations [4]. - The team averages six night-time maintenance sessions per week, walking approximately 12,000 steps during each operation, which involves a round trip of about 8 kilometers [4]. - The team utilizes drones for inspections to cover blind spots and enhance the accuracy of their checks, identifying issues such as loose bolts that require immediate attention [5]. Group 2: Working Conditions - The maintenance work occurs in a cold, dark environment, with temperatures in the tunnel being particularly low due to lack of sunlight, making the conditions challenging for the workers [3][6]. - The team members are equipped with minimal protective gear, such as thin insulating gloves, to perform precise tasks while ensuring the reliability of the power supply [4][5]. - The maintenance operations are conducted during the early hours, with the team working through the night to complete inspections and repairs before the morning rush [6]. Group 3: Achievements - The maintenance team successfully completed inspections of 6.2 kilometers of contact network and 9.39 kilometers of cables, addressing multiple safety hazards during their night shift [5][6]. - The operations are crucial for maintaining the "lifeline" of power supply during the Spring Festival, ensuring a safe return journey for travelers [6].