View source for China Railways SS7

{{short description|Chinese electric locomotive class}}
{{Infobox locomotive
| name = SS7<br>韶山7
| image = China Railways SS7 0083 20171217.jpg
| caption = SS7-0083, [[:zh:鹧鸪江站|Zhegujiang railway station]], December 2017
| powertype = Electric
| builder = [[Datong locomotive factory|CRRC Datong]]
| buildmodel = SS<sub>7</sub>
| builddate = 1992–2007
| totalproduction = 113
| uicclass = Bo'Bo'Bo'<br>(Except SS7E use Co'Co')
| gauge = {{track gauge|sg}}
| wheelbase = {{convert|17080|mm|ftin|abbr=on}}
| length = {{convert|22016|mm|ftin|abbr=on}} (between coupler centers)
| width = {{convert|3105|mm|ftin|abbr=on}}
| height = {{convert|4700|mm|ftin|abbr=on}} ± {{convert|30|mm|abbr=on}}
| axleload = {{convert|23|t|1|abbr=on}}
| electricsystem = [[25 kV AC]] [[Overhead line|Catenary]]
| collectionmethod = [[Pantograph (rail)|Pantograph]]
| transmission = AC – DC
| maxspeed = {{convert|100|km/h|abbr=on}}
| poweroutput = {{convert|4800|kW|hp|abbr=on}}
| tractiveeffort = {{convert|485|kN|abbr=on}} (starting)<br />{{convert|351|kN|abbr=on}} (continuous)
}}
The '''Shaoshan 7''' ({{zh|c=韶山7}}) is a type of [[electric locomotive]] used on the [[People's Republic of China]]'s national railway system. They are widely used on electrified lines in the southwest part of China.

==Design==
The design of SS7 was influenced by the [[China Railways 6K|6K]], an electric locomotive model imported from Japan.<ref name="test">[http://www.trainnets.com/archives/5610 SS7型电力机车] _trainnets.com</ref>

The first SS7 was built in 1992 in [[Datong]]. In 1997, SS7s were used in [[Nanning-Kunming Railway]]. However, SS7's frequent failure lead to Datong Electric Locomotive Works making improvements to SS7s. Failure was reduced to just four cases in one year in 2004.

SS7 Electric Locomotive was still produced as of 2007. Most of SS7s belong to [[Liuzhou Locomotive Depot]], [[Nanning Railway Bureau]].<ref>Include SS7B-0002.</ref> The last two SS7s (8112 and 8113) belong to Xiaoyi-Liulin Railway, which is located in [[Shanxi]].

==Derivatives==
Derivatives of SS7 include SS7B, SS7C, SS7D and SS7E.

=== SS7B ===
{{main|China Railways SS7B}}
In 1997, Datong Electric Locomotive Works developed the SS7B Electric Locomotive. There were only two SS7Bs manufactured, both SS7Bs' each axis axle load 25 tons.<ref>[http://www.trainnets.com/archives/9012 SS7B型电力机车] _trainnets.com</ref>

At first, two SS7Bs belonged to Kunming Locomotive Depot, Kunming Railway Bureau. Later the two SS7Bs were transferred to [[Nanning Locomotive Depot]], [[Nanning Railway Bureau]]. In 2005, SS7B-0001 was destroyed in an accident which happened on the Nanning-Kunming Railway.<ref>[https://web.archive.org/web/20050318020559/http://news.xinhuanet.com/newscenter/2005-03/18/content_2711811.htm 一列货车颠覆致使南昆铁路中断]</ref><ref>[http://www.anquan35.com/Info/accidentcasedetail-84828.html 南昆线45224次货物列车脱轨重大事故]</ref>

=== SS7C ===
In 1998, Datong Electric Locomotive Works and Zhuzhou Electric Locomotive Research Institute, Chengdu Locomotive and Rolling Stock Works developed SS7C Electric Locomotive. There were 171 SS7Cs manufactured.

SS7Cs' each axis axle load 22 tons, and support head-end power. Its maximum speed is {{convert|120|km/h|abbr=on}}.

=== SS7D ===
In 1999, Datong Electric Locomotive Works and Zhuzhou Electric Locomotive Research Institute, Chengdu Locomotive and Rolling Stock Works developed SS7D Electric Locomotive. There were 59 SS7Ds manufactured, and belong to Xi'an Locomotive Depot, Xi'an Railway Bureau.

SS7D use lightweight design, each axis axle load 21 tons, and support head-end power. Its maximum speed is {{convert|170|km/h|abbr=on}}.

=== SS7E ===
In 2001, Datong Electric Locomotive Works and Dalian Electric Traction R & D Center, Dalian Locomotive & Rolling Stock Works developed the SS7E Electric Locomotive. There were 146 SS7Es manufactured.

SS7E use lightweight design, however its axle arrangement is Co'Co'. Each axis axle load 21 tons, and support head-end power. Its maximum speed is {{convert|170|km/h|abbr=on}}.

== Named locomotive ==
* SS7-0076, "May 4th's Red Flag" (Chinese: 五四红旗号).
* SS7D-0631,"Steelers Iron Horse"(Chinese: 钢人铁马号).

== Gallery ==
<gallery widths="150">
SS7-0076.jpg|SS7-0076 "4 May's Red Flag", [[Shilin Yi Autonomous County|Shilin]], 1999
China Railways SS7B 0002 20180526 02.jpg|SS7B-0002, May 2018
China_Railways_SS7_0082_20171223.jpg|SS7-0082 is a verify locomotive during the development China Railways SS7C.<ref name="test" />
SS7C0142.jpg|SS7C-0142 locomotive at Wuchangnan Locomotive Depot.
SS7D 0029.jpg|SS7D-0029 in Xianyang railway station.
China Railways SS7D 0011.jpg|SS7D-0011 in Xi'an railway station
SS7E 0097 Beijing West Railway Station 20111004.jpg|SS7E-0097 in [[Beijing West railway station]].
SS7E 0113.JPG|SS7E-0113 in Xi'an railway station
</gallery>

== Manufacturers ==
SS7s have been manufactured by several companies:
* Datong Electric Locomotive Works (Most of SS7s.)
* [[Dalian locomotive works|Dalian Locomotive & Rolling Stock Works]] (SS7E Electric Locomotive's 7000 Series.)

==References==
<references />

{{commons category|China Railway SS7}}

{{Locomotives of China}}

[[Category:Bo-Bo-Bo locomotives]]
[[Category:Electric locomotives of China|SS7]]
[[Category:25 kV AC locomotives]]
[[Category:CRRC Datong locomotives]]
[[Category:Railway locomotives introduced in 1992]]
[[Category:Standard-gauge locomotives of China]]


{{electric-loco-stub}}