The DJF2 "Xianfeng" electric multiple unit is a model operated formerly by China Railway with traction motors distributed throughout the unit. It was developed in 2001 as a key task of the science and technology targets of the Ninth Five-Year Plan. It was an innovative and advanced design being the first Chinese multiple unit train to achieve and achieving a top test speed of in tests, but had numerous flaws in the design that complicated operations.
Developmental history
Background
Before the 1990s, the maximum speed at which services operated in China had long remained at or below, and faced increasingly steep competition from airplanes and highways. In 1990, the Ministry of Railways decided to upgraded the Guangshen railway to an experimentally higher speed section, with a speed of , to explore various ways in which high-speed rail may be future developed. In December 1994, the upgraded Guangshen railway was put into service, which demonstrated the basics for future development of high-speed rail. After numerous experiments, the First railway speed-up campaign was launched on 1 April 1997.
To increase the competitiveness of the railways, the ministry set a target for a high speed EMU. In the Ninth Five-Year Plan, there were two such targets relating to the development of trainsets:
passenger EMU (fulfilled by DDJ1) power separated AC EMU (fulfilled by DJF2)
Development
The " power separated EMU" was designed with the participation of Nanjing Puzhen Rolling Stock, Tongji University, China Academy of Railway Sciences, CRRC Zhuzhou Institute, Datong Locomotive, Yongji Electric, Central South University, and some other minor companies, with Puzhen leading the design. Technological innovations that the set featured were the power and trailer bogies, the control system, the traction motors, traction transformers, the AC–DC–AC drive, gearbox, primary and auxiliary electronics, and some other components. The design was planned to operate at speeds between , with a maximum speed of .
The design of the set was completed at Puzhen in 1999, and submitted the plan for approval; construction began in August 1999. By June 2000, the overall structure was complete, and tests were undertaken on the high-speed bogies. Assembly was completed in December 2000, and the vehicle started running in, and it was accepted by the Ministry of Railways.
Trials
The DJF2 was rolled out from Puzhen on 23 May 2001, and was named "Xianfeng". Two days later, it arrived at the China Academy of Railway Science Beijing Ring railway to undergo comprehensive tests. From 1 August to 18 September, the "Xianfeng" performed safety tests at a speed of . From 26 October to 16 November, it underwent testing under the watch of the ministry, China Railway Guangzhou Group, CSR, China Academy of Railways on the Guangshen railway for high speed testing. On the night of 10 November, the set broke the Chinese train speed record, hitting . From December 2001 to June 2002, it underwent another half year of testing and adjustments on the Guangshen railway.
Between 2001 and 2002, before starting operation on the Qingshen passenger railway, the set underwent another three rounds of comprehensive testing, to check the safety of the new Qingshen railway, but also to provide experimental data for the Jinghu railway and to collect data on even higher speed trains of . In the second such test from 5 to 12 September 2002, the "Xianfeng" collected various data on the traction, braking, behaviour at track switches, the effect on the pantograph at high speeds and the train warning system, while also testing the rails, switches, viaducts and signals of the new high speed line. On 10 September 2002, the train once again broke the Chinese speed record, reaching on the Qingshen railway.
After travelling , the Ministry of Railway decided to expand the "Xianfeng" EMU from six to nine cars, and was listed as a task in the Tenth Five-Year Plan, which Puzhen took up, with their design being approved in March 2003. In June 2003, the "Xianfeng" was called back to Puzhen in preparations for modifications and expanding the consists. However, with the replacement of the Minister of Railways from Fu Zhihuan to Liu Zhijun, the developmental plans of China Railways changed, and the plans for expanding the consist was dropped. Afterwards, the ministry requested a run in instead, and after completing an overhaul, the "Xianfeng" started a passenger service trial service from 20 February 2004, until it completed its run-in on 19 October 2004. During this period, it ran twice daily from Huanggutun station to Shanhaiguan station with the service number 55201/2/3/4.