April 6, 2012, HY announced a full and successful completion of the result-determined natural gas pipeline construction project by HDD through Yangtze River from Huanggang to Daye.
The Huang-Da line Yangtze River crossing is located at the 6.5km away from the downstream of E-Huang Bridge, with the horizontal length 2677.3m, curve length 2686.3m and diameter Φ610mm. The pipeline is set to be crossed a complicated geological condition like the large fracture of Xiangfan-Guangji, round stone, pebble, argillaceous siltstone, calcareous sandstone, silty mudstone, conglomerate, calcite dolomite, Andesitic tuff and karst cave etc.
Because of the long crossing distance and the high rock hardness, the reaming is the most harsh stage in this project. According to this, HY independent-developed the automatic reamer with a 3-times reaming speed than the conventional one to improve the reaming efficiency. The 3 grades reaming of Φ700, Φ800 and Φ900 were done within 80 days.
2012. April 6. 12:36, the pull-back stage was finished perfectly. This project marked a new milestone of HY.