Jan. 19, 2018 -- Sangzhuling tunnel, the first super long tunnel on the Sichuan-Tibet railway, was completed on Wednesday, China News Service reported.

The total length of the tunnel is 16.449 kilometers. The maximum rock temperature inside the tunnel is 89.9 C, the highest temperature encountered during any railway construction in China, making it difficult to tunnel through.

Sangzhuling tunnel is one of the most important engineering projects of the Sichuan-Tibet railway, which is one of the five railways that connect Southwest China's Tibet autonomous region to the rest of the country.