ON JUNE 28 the first of two prototype diesel locos being built for Chinese Railways was rolled out of the Dalian Locomotive & Rolling Stock Works. Derived from the proven DF4d, the six-axle 4000hp locos are part of CR’s strategy to develop AC transmissions, being equipped with the latest Siemens IGBT converter drives.

Siemens is providing the traction equipment for the two prototypes under a joint development and co-operation agreement signed with DLRW in April 1999. Dalian currently builds around 300 DC-motored diesel locos a year for CR, and the intention is to switch the bulk of production to AC drives within the next few years.

Designated DF4dac, the locos will have a starting tractive effort of 555 kN and a top speed of 145 km/h. Following commissioning runs at the China Academy of Railway Sciences test track near Beijing, they are due to start revenue service trials on the CR network next month.