ChS7

ChS7[1]
Electric locomotive ChS7
Power type	Electric
Builder	Škoda Works
Build date	1983-1999
Total produced	321
Gauge	1,524 mm (5 ft)
Electric system	3000 V DC
Current collection method	Pantograph
Top speed	160 km/h (99 mph)
Career	РЖД (RZhD), УЗ (UZ)
Locale	Russia Soviet Union Ukraine

The ChS7 Russian: ЧС7 is an electric mainline DC passenger locomotive used in Russia and Ukraine. The locomotive consists of tow sections (type 2(2O−2O)). This particular models was released in the years of 1983 to 1999. on V.I. Lenin (Skoda) plant in the city of Plzen, Czech Republic especially for the railways of Soviet Union(consequently Russia and Ukraine). Equally with ChS8, Chs7 is now one of the most powerful electric locomotives, used in the countries former USSR.

Premise for the appearance

By the early 1980s the ridership of soviet railways riched significant quantity. It was required to increase the number of passenger trains, which was prevended by an excessively huge freight traffic, and inability to increase passenger capacity of trains by means of increasing the number of cars (30 and more) which could consequently increase the weight to haul. In order to fulfill the last task strong and powerful electric locomotives were required. However, the basis of soviet electric locomotive rolling stock was ChS2 (DC) and ChS4 (AC) electric locomotives, as well as of VL60p (passenger version of VL60). The powere of those electric locomotives was 4200–5100 kW, while a traction force did not exceed 17400 kgs, which was not enough for pulling 30-car passenger train. In addition their design developed back in the 1950s became obsolete. It is worth to mention that, ChS2 control scheme encountered the capability of working with more the two units in a Multiple-unit train control mode, but due to a couple of imperfections (for example it was impossible to restore the protection of traction engines of the "slave locomotive" from a leading locomotive), this kind of traction were either not in used or used but extremely rarely.

• Since 1971—1972 V.I. Lenin plant in Plzen started to produce various modifications of ChS2T and ChS4T locomotives. In comparison to their prototypes, those locos were different by a better design, in addition ChS2T was even stronger than its prototype; however their traction force was not sufficient.
• Besides, starting with the second half of the 1970s the party of ChS6 8-axle DC electric locomotives were in use on Oktyabrskaya Railway. These electric locomotives were created on basis of high speed Chs200 locos by means of changing the transition number of traction reductors, while the total power of their engines were 8400 kW.
• However these electric locomotives were not appropriate for pulling heavyweight passenger trainsв, since the dis-congruence between traction engine power and chain weight (164 tons) did not allow to increase the traction force significantly. IN additions Chs6 locos had only two economical speeds 2 which made their speed range, yet limited. This fashion, their construction required further improvements
• This is the way the SKODA plant in Czechoslovakia (formerly V.I.Lenin plant) in 1980s received an order for building strong and powerful passenger electric locomotives, which were able to pull trains composed of 32 passenger cars.

Production

For a purpose of driving heavy train, by the early 1980s SKODA plant projected universal AC/DC 8-axle locomotive. (Refer to ChS8). They were designated for pulling trains along the hard-to-pass profiles. For the purpose of projecting new electric DC locomotive, ChS6 and ChS200 features were used as a basis; as compared with these two projects, Chs7 featured several changes. The following changes can be mentioned there:

See also

References

1. ^ Collection of articles about ChS-7 in Russian on scado.narod.ru