Inner Mongolia's coal is transported to the sea on the Daqin line between Datong and Qinhuangdao. Shortly after the turn of the millennium, the planned capacity of 100 million tonnes per year was reached there. Since this could even be quadrupled in the following years through continuous expansion measures, the only 20 DJ1s built and the older electric locomotives quickly reached their limits. For this reason, the HXD1 was developed again in cooperation with Siemens as a direct successor to the DJ1.
The HXD1 is based on the then current generation of the EuroSprinter and uses modern IGBT pulse-controlled inverters to convert the alternating current instead of the outdated thyristor. Again the concept of two permanently coupled locomotives, each with four axles and an axle load of 23 tonnes, which can be increased to 25 tonnes with ballast if the rails are strong enough, was used. This results in the same starting tractive effort as with its predecessor, but due to the increased continuous output of 9,600 kW each, higher tractive effort at higher speeds. This enables them to pull coal trains with up to 216 wagons and a weight of 20,000 tonnes. A total of 271 HXD1 were built in multiple series between 2006 and 2012.
In addition to the Chinese State Railways, the company China Shenhua Energy also owns some of these locomotives for use on their own coal railways. Only a liberalization of market policy made it possible to deliver these locomotives based on foreign technology to a company outside the state railway. Some of these locos can be recognized by a revised, more rounded front and, like the prototype HXD1-1000, have a larger proportion of purely Chinese equipment. In addition to the conventional HXD1, Shenhua has also been operating two three-section locomotives since 2013. In 2020, the order followed for up to 13 six-section “Shen 24”, which, with their 24 axles, will be around 106 meters long. With a continuous output of 28,800 kW, they are considered the most powerful multi-section locomotives in the world. Visually, these in turn are characterized by a new, squarer head shape.
