The agreement signed by Alstom and the Ministry of Railways and its agent CNTIC in June 2004 will see the first of 180 locomotives take to the rails in China in January 2007.

Based on the Prima design being supplied to SNCF, China’s Prima 2U will be a twin-unit locomotive intended to haul heavy coal trains on the 653 km Datong - Qinhuangdao route which is electrified at 25 kV 50Hz. Intensive utilisation has been specified, with locos operating for 17 out of 24 h on trips that require 625 km runs without stopping. Initially, pairs of Prima 2U locos will haul 10000 tonne trains, but the objective is to move to 20000 tonne trains powered by three locos using remote control.

Each Prima 2U will be rated at 10000 kW. Maximum speed will be 80 km/h, although the locos are designed to run at 120 km/h. Diagramming will see each loco cover an average distance of around 800 km a day or 200000 km a year. Between trips the locos will be maintained at Hudong depot near Datong.

The first 12 locos will be designed and assembled in Belfort, and the following 24 will be supplied as kits from France for assembly at Datong. Technology transfer arrangements will permit the remaining 132 to be built in China, turning out up to 14 locomotives a month. Datong will supply bodyshells, bogies and common blocks and Yongji will provide traction motors and motor blocks. A 23 tonne axleload will increase to 25 tonnes with ballast, and equipment has been designed to withstand temperatures ranging from -25°C to +40°C. On-board accommodation for drivers includes a bed and a refrigerator.