Hongyancun Station in Southwest China's Chongqing Municipality Photo: Screenshot from Pear Video

The 100-meter-deep Hongyancun Station in Southwest China's Chongqing Municipality, the deepest subway station in the country, will go into operation by the end of 2021. 

The station, which is under construction, is 106 meters below the ground, equivalent to the height of a 35-story building. Nine vertical shafts are being used to build the station, three of which are over 100 meters deep. 

More labor is being used in the construction of the station than for normal ones, said Xi Yaoyong, who is in charge of the construction process, in a video posted by Pear Video on Monday. 

He said that it usually takes half an hour for workers to climb out of the shafts, and that he had worn out a pair of shoes in as short as three months.

The greatest amount of labor is used in a 368-meter-long inclined shaft with a 30-degree slope, he said, noting that workers spend half a day just moving building materials such as steel bars. 

Chongqing is known as a "mountain city" due to its combination of mountainous terrain and urban architecture. The city's special landscape has also made its subway stations different to most other cities' as many of them were built either high above the ground or deep below it. 

Hongyancun Station is expected to replace Hongtudi, another subway station in Chongqing, as the deepest in China. Hongtudi Station is 94 meters deep and has eight escalators.