Located 10 kilometers northwest of Bailang Town in Aershan City, it is 1227 meters above sea level and 3218.5 meters in length. It is the longest railway tunnel in the eastern part of Inner Mongolia Autonomous Region and the only way for trains to Aershan City.

Every morning, the K7595 train from Baicheng to Aershan has to cross the mountain. It only takes 6 minutes for the train to pass through the tunnel. However, few passengers know that there are gates at both ends of the Nanxing'an tunnel.

The Nanxing'anling Tunnel is located in an alpine mountainous area where the temperature can reach as low as minus 40 degrees Celsius in winter. In order to reduce icing and ensure driving safety, thermal gates are installed at both ends of the tunnel.

"At the north entrance of the tunnel, the train has passed Bailang Station, please open the tunnel gate!", "The north entrance of the tunnel is here, open the tunnel gate immediately!" China Railway Shenyang Bureau Group Co., Ltd. Paicheng Public Works Section Sauron Bridge Tunnel Workshop Patrol Sauron Bridge Tunnel Work Area The guard Han Chunfu came to the entrance of the Nanxing'an Tunnel, inserted a 3-meter-long steel pipe into the door handle, and held the steel pipe tightly to open the 5.5-meter-high gate. After fixing the gate, Han Chunfu returned to the pick-up position, waited for the train to pass safely, and then closed the gate in time.

During the Spring Festival travel period, the trains are encrypted, and the patrolmen who stick to the north and south entrances of the tunnel have to open and close the gate more than 30 times a day. With the mutual cooperation of him and his colleagues, the trains ran unimpeded in the past seven years, and spent the last Spring Festival on the post.

In winter, the temperature in the tunnel decreases, and the water leaking from the roof and the wall of the cave forms long ice skates. If it is not removed in time, it will bring safety hazards to driving. When breaking the ice skates, when removing the ice skates on the top of the tunnel, due to the vertical operation, the ice cubes or crushed ice go directly into the neck collar. During the de-icing operation, the patrolmen at the south and north entrances will exchange "handover cards" in the tunnel and return to their posts after learning about the de-icing conditions.

Day after day in the long winter in Aershan, the wind and snow are unobstructed. Due to the special geographical location, it is impossible to dig wells here. The daily water needs to go to the creek under the mountain to break the ice to get water. It takes more than an hour to walk on the 1-kilometer mountain road, and the fresh vegetables are frozen after being transported, so every time the patrolman on duty brings food for 3 days.

There are no people within 10 miles of the Nanxing'an Tunnel, and only mountains, tunnels, and trains accompany them every day. The 59-year-old Han Chunfu spent the last Spring Festival on the job. He said: "In previous years, I was looking forward to getting off work and reuniting with my family, but this year, I hope the time will pass a little slower, and I want to see more of this man who has accompanied him for 7 years. Dashan, stand on the last guard!"Editor/Ma Xue