China Railways DF11. The  DF11 () is a semi-high-speed diesel-electric locomotive used on the People's Republic of China's national railway system. This locomotive was built by Qishuyan Locomotive and Rolling Stock Works.

Overview 
The China Railways DF11 is a semi-high-speed passenger diesel-electric locomotive. It was an important scientific and technological objective of China's Eighth Five-Year Plan, and was designed for  runs on the Guangzhou-Shenzhen Railway. The Guangzhou-Shenzhen Railway opened with an operating speed of , utilizing high-speed passenger trains and the level of potential development of a new type of high speed passenger diesel locomotive.

By the end of 1990 development had begun by the Qishuyan Locomotive Works, who modified a DF9 locomotive, changing traction motor gear transmission ratio, thereby increasing the maximum speed from  up to . The new locomotive was then tested to obtain the experimental data for high-speed diesel service.

In 1991, the Ministry of Railways ordered the new locomotive based on the design plans developed by the Qishuyan plant. Code-named the DF11, the first DF11-0001 was completed in December 1992, with the test trials completed in August 1993. The next locomotive, No. 0002, reached the maximum speed of  during a test in the National Railway Test Centre (Eastern Suburbs Branch) in April 1994.

After the completion of the trials, the DF11 was formally placed into service on the Guangzhou-Shenzhen High Speed Railway Line in December. Production of the DF11 has stopped production as of 2005, Qishuyan factory produced 459 units total (license number 0001-0458, 1898), with DF11 1898 being named "The Zhou Enlai" (the number is the same as Zhou Enlai's year of birth), belonging to Shanghai Railway Administration Shanghai Locomotive Depot.

The DF11 diesel locomotive is equipped with an AC-DC electric transmission, 16V280ZJA diesel engine, 1 × three-phase AC synchronous alternator model JF204C, and 6 × ZD106 DC traction motors. Maximum braking power from the diesel is , with nominal wheel power at , capable of sustaining operating speeds of up to . Maximum design speed of the Co-Co trucks is 170 km/h.

The cab design incorporates a 25° inclination for streamlining. The locomotive microcomputer control system consists of constant power excitation control, cooling, anti-wheel slip transfer control, fault diagnosis display, with full power to test the resistance of dynamic braking system functions, and electro-pneumatic braking system. The DF11 can haul a  passenger train (about 12 cars) up to the maximum balancing speed of  on straight track; or a  train (about 20 cars) to a maximum balancing speed of .

In addition, the DF11 locomotives are designed for Xinjiang, Ürümqi Railway Bureau plateau type of configuration, mainly to increase the output of power, and installation of sound bilateral air intake/air filtration/filter sand unit, and to increase the gear ratio change from 76:29 to 65:22, increasing starting traction and sustained traction. However, the maximum speed is reduced to . 

Formerly, the class served the Guangzhou-Kowloon Through Train before being replaced by SS8 electric locomotives.

Major incidents 

On 28 April 2008, DF11-0400 locomotive, hauling Train No. 5034, collided with the derailed Train No. T195 in the Jinan-Zibo section of the Jiaoji Railway. The DF11-0400 locomotive was declared destroyed beyond repair and later scrapped.

Gallery

See also 
 List of locomotives in China
 China Railways DF9
 China Railways DF11G

External links 

 locomotive description from builder (CSR)
 DF11 Profile on trainspo.com

DF11
Standard gauge locomotives of China
Railway locomotives introduced in 1992
Qishuyan locomotives
Co′Co′ locomotives