Datong-Qinhuangdao Railway is 653 kilometers long , which is the first double-line electrified heavy-duty coal transportation line in China. A heavy-duty train depart at 12-minutes interval. It has set a number of world records such as the highest density of single railroad heavy-duty trains, the largest capacity, the fastest increase in transportation and high transportation efficiency.

In August 2022, Aigre carried out reconstruction of the existing line of the Chawu section on the Datong-Qinhuangdao Railway. The project had to be implemented without affecting the transportation , as coal transportation can’t be stopped. The construction is difficult and the construction period is tight. On the project, after the work of the "dismantling the old rails and replacing the new rails" is completed, the transportation of heavy train will be resumed immediately. Therefore, it puts forward a great test for the rail welding quality. Continues more than 30 day-long fights in this field, Aigre solved the technical difficulties and successfully completed the the Chawu existing line railroad reconstruct project. The 126 weld joint had a 100% pass rate.