Progress made on tunnel build for Beijing-Zhangjiakou railway(1/4)

A view of the entrance to the Nankou Tunnel, part of the Beijing-Zhangjiakou High-speed Railway in Changping District, Beijing, March 28, 2019. Construction of the main structure of the tunnel is now complete. The tunnel is 3,032 meters long and has a designed speed of 250 kilometres per hour. The 174-km-long railway is a major transportation project for the 2022 Winter Olympic Games. (Photo: China News Service/Jia Tianyong)

A worker inside the Nankou Tunnel, part of the Beijing-Zhangjiakou High-speed Railway in Changping District, Beijing, March 28, 2019. Construction of the main structure of the tunnel is now complete. The tunnel is 3,032 meters long and has a designed speed of 250 kilometres per hour. The 174-km-long railway is a major transportation project for the 2022 Winter Olympic Games. (Photo: China News Service/Jia Tianyong)

A worker inside the Nankou Tunnel, part of the Beijing-Zhangjiakou High-speed Railway in Changping District, Beijing, March 28, 2019. Construction of the main structure of the tunnel is now complete. The tunnel is 3,032 meters long and has a designed speed of 250 kilometres per hour. The 174-km-long railway is a major transportation project for the 2022 Winter Olympic Games. (Photo: China News Service/Jia Tianyong)

A worker inside the Nankou Tunnel, part of the Beijing-Zhangjiakou High-speed Railway in Changping District, Beijing, March 28, 2019. Construction of the main structure of the tunnel is now complete. The tunnel is 3,032 meters long and has a designed speed of 250 kilometres per hour. The 174-km-long railway is a major transportation project for the 2022 Winter Olympic Games. (Photo: China News Service/Jia Tianyong)