The SS8 is a 25kV 50 Hz AC electric locomotive

Electric locomotive

An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or an on-board energy storage device...

 used on the Peoples' Republic of China's national railway system. The only route they were used on was the Jingguang line

Jingguang Railway

The Beijing–Guangzhou Railway or Jingguang Railway is a major arterial railway in the China that connects Beijing in the north with Guangzhou in the south. This dual-track electrified line has a total length of 2,324 kilometres and spans five provinces through north, central and south China...

, the railway line linking Beijing West Railway Station

Beijing west railway station

Beijing West Railway Station, also known as Beijing West or West Passenger Station is located in western Beijing's Fengtai District. Opened in early 1996 after three years of construction, it was the largest railway station in Asia with 510,000m². The station serves in average 150,000–180,000...

 with Guangzhou

Guangzhou

Guangzhou , known historically as Canton or Kwangchow, is the capital and largest city of the Guangdong province in the People's Republic of China. Located in southern China on the Pearl River, about north-northwest of Hong Kong, Guangzhou is a key national transportation hub and trading port...

, Guangdong

Guangdong

Guangdong is a province on the South China Sea coast of the People's Republic of China. The province was previously often written with the alternative English name Kwangtung Province...

.

The SS8 is based on its predecessor, the SS5, and was developed and built by CSR Zhuzhou Electric Locomotive Works. A total of 245 (0001–0243, 2001–2002) SS8s have been built since 1994. Batch production commenced in 1997.

On June 24, 1998, the SS8 broke the Chinese rail speed record

Land speed record for railed vehicles

Determination of the fastest rail vehicle in the world varies depending on the definition of "rail".Official absolute world record for conventional train is held by the French TGV...

 by achieving a top speed of 240 km/h (149.1 mph) on a test run between Xuchang

Xuchang

Xuchang is a prefecture-level city in central Henan province in Central China. It borders the provincial capital of Zhengzhou to the northwest, Kaifeng to the northeast, Zhoukou to the east, Luohe to the southeast, and Pingdingshan to the southwest....

 and Xiaoshangqiao

Xiaoshangqiao

Xiaoshangqiao is a place in Henan, China....

. The locomotive used was fleet number 0001.

Allowance of KCR

When the Guangzhou-Shenzhen Railway was electrified, China Railway extended Through Trains into Hong Kong via KCR East Rail. These trains initially had an SS8 locomotive

Locomotive

A locomotive is a railway vehicle that provides the motive power for a train. The word originates from the Latin loco – "from a place", ablative of locus, "place" + Medieval Latin motivus, "causing motion", and is a shortened form of the term locomotive engine, first used in the early 19th...

, however, their pantograph

Pantograph (rail)

A pantograph for rail lines is a hinged electric-rod device that collects electric current from overhead lines for electric trains or trams. The pantograph typically connects to a one-wire line, with the track acting as the ground wire...

s are considered harmful to KCR's catenary. So for a long time, DF11

China Railways DF11

The Dongfeng -11 diesel locomotives , is a quasi- high-speed diesel locomotive , from China Qishuyan Locomotive Works Manufacturing Co. used by the China Railway.- Overview :...

locomotive were used. After KCR provided their technical requirements of HK-compliance pantographs to China Railway, the company adapted some ot their SS8's in order to meet the pantograph requirements. As of March 2010, the SS8 is still the only allowed China Railway electric locomotive in Hong Kong.