Tunneling through the Yangtze River for the China-Russia East-Route natural gas pipeline started in Haimen district, Nantong on May 18. [Photo/WeChat account: jshmrb]

Tunneling through the Yangtze River for the China-Russia East-Route natural gas pipeline started in Haimen district, Nantong on May 18.

The structure has an inner diameter of 6.8 meters and an outer diameter of 7.6 meters, which will allow three pipes, each measuring 142.2 centimeters in diameter, to pass through.

It also has a horizontal length of 10.23 km and a maximum water pressure of 0.73 Mpa, setting world records for cross-river shield structure construction with the longest single-side excavation, deepest buried depth, highest water pressure, as well as largest diameter in the oil and gas pipeline field.

Located in the estuary of the Yangtze River, the structure requires extreme care, as it will pass the river's major channel, dams, and wharfs, officials said. The section is also a reserve of rare fish in the river.

The last section of China-Russia East-Route will go from Yongqing county in Hebei province to Baihe town in Shanghai, crossing big gas-consuming provinces Shandong and Jiangsu.

It is scheduled to be completed in 2025. By then, the pipeline is expected to transport 18.9 billion cubic meters of natural gas from Russia to the Yangtze River Delta region every year.

Officials said that this will not only enhance the region's emergency support capacity to meet the development needs of natural gas and people's gas needs, but also significantly improve the air quality in the region.