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Chinese Railways develops traction to meet market needs

01 Aug 2000

INTRO: The latest diesel and electric locomotives developed in China for high speed and heavy haul service offer dramatic advances in performance over earlier designs

BYLINE: Kang Xiong

Assistant Vice President, China Academy of Railway Sciences

IN THE LAST decade Chinese Railways has made considerable efforts to develop its own motive power. Both high speed passenger trains and another generation of heavy haul freight locomotives are in prospect to haul trains on new railways now planned or under construction. The CR network has been growing steadily, and at the start of 2000 CR operated services over 58000 route-km.

Before 1949 the majority of CR's locomotive and car fleet was imported, but then Chinese Railways began to develop its own manufacturing capability. The first steam locomotive was manufactured in 1952, the first diesel in 1958 and the first electric in 1960. The ensuing 40 years have seen enormous technical progress, with diesel and electric locomotives becoming increasingly powerful and the output per driven axle also rising.

As a result, locomotive performance has improved markedly, and CR now has a well-developed range of motive power. Production of steam locomotives was phased out in 1988, and the latest technology is being applied to diesel and electric traction.

First 160 km/h running

At the start of the 1990s the maximum speed of our passenger trains was 80 or 100 km/h, with an average of only 48·3 km/h. In 1990 work began on building the quasi-high speed railway from Guangzhou to Shenzhen, and this led to major changes in locomotive design. Research and development carried out at the China Academy of Railway Sciences was instrumental in the production of CR's first batch of locomotives and coaches able to run at 160 km/h. By this time the capabilities of the Chinese rolling stock industry had improved to a great extent, enabling local suppliers to meet the demanding requirements of CR's plans for running faster trains.

Since 1997 CR has been working on a programme to increase the speed of passenger and freight trains on its principal trunk routes. On April 1 1997 CR launched a network of fast inter-city services linking major cities such as Shenyang, Beijing, Shanghai, Guangzhou and Wuhan. They included 11 pairs of passenger trains timed to run at a maximum speed of 140 km/h and an average commercial speed of 90 km/h. Given the long distances in China, it was sensible to make use of overnight services, and 78 pairs of passenger trains with evening departures and next morning arrivals were introduced. Several fast freight trains with similar schedules also began operating.

In October 1998 the maximum operating speed was further raised to 140 or 160 km/h on certain sections of the three major trunk lines: Beijing - Guangzhou, Beijing - Shanghai and Beijing - Harbin. In southern China an X2000 tilting train from Sweden with a maximum speed of 200 km/h was leased to run on the Guangzhou - Shenzhen route. At the same time more freight train schedules were accelerated.

The Chinese rolling stock industry was by this time able to produce large series of locomotives and coaches able to run at relatively high speeds, and these were followed by several designs of EMU and DMU for specific markets. The main technical specifications are shown in Tables I to IV.

Speed records

The programme to increase train speeds helped to accelerate scientific and technological progress on CR as it required the development of modern engineering techniques and the introduction of new technology. In January 1997 a record speed of 212·6 km/h speed was attained on the CARS test loop near Beijing where new designs of rolling stock undergo trials and are commissioned before entering passenger service.

This was followed by a further speed record in June 1998 when 239·7 km/h was recorded on the Zhengzhou - Wuhan section of the Beijing - Guangzhou line. This provided a good scientific base for proposed 200 km/h dedicated passenger lines and also for the research and design of true high-speed railways in China.

With regard to freight transport, heavy haul trains grossing 5000 tonnes are now quite common on the main trunk lines. For example, on certain sections of the Beijing - Guangzhou line 30 to 40 pairs of 5000 tonne trains run daily, with 67 pairs of trains of a similar weight on the purpose-built Datong - Qinhuangdao coal line.

The latest Chinese-built diesel and electric locomotives for heavy haul duties have 25 tonne axleloads. As more of these units enter service, CR's capacity to handle growing tonnages is growing steadily. It is also helping to match supply more closely to demand on the busy main lines.

Future prospects

In the next few years CR's main research and development work will concentrate on three main areas. First is the development of modern drive technology with asynchronous motors, which offers many advantages. At present Chinese-built electric and diesel locomotives still use conventional technology with AC being converted for use in DC motors.

The first prototype electric locomotive with variable-voltage, variable-frequency current for asynchronous traction motors, the AC4000, was produced in China in 1996, but series production has not yet started. Efforts will therefore be made to develop this technology to the point where it can be used in diesel and electric locomotives and in multiple-units. We hope to achieve this in the next few years.

The second strategic field for technical development is high speed trains. We plan to build an EMU able to run at 200 km/h, as well as motive power capable of running on dedicated lines at 300 km/h. In parallel we also plan to develop tilting trains with our own intellectual property rights.

The third area of development will be new types of bogie for locomotives and freight wagons. This will be matched by improvements to achieve better reliability and maintainability, through the development of 'intelligent' locomotives and wagons equipped with microcomputer control, monitoring and fault diagnosis. We shall actively pursue research into energy-saving motive power with low noise emissions. Diesel traction with reduced exhaust emissions is also needed to reduce environmental impact.

In short, we must set up our own technical systems to meet the actual conditions of service in China. Tomorrow's motive power must keep pace with development trends so that CR catches up with other countries where technology has already reached very advanced levels.

TABLE: Table I. Recent electric locomotives

Class SS8 SS9 SS7d

Wheel arrangement Bo-Bo Co-Co Bo-Bo-Bo

Transmission AC-DC AC-DC AC-DC

Power rating kW 3600 4800 4800

Continuous tractive

effort kN 126 169 171

Starting tractive

effort kN 210 286 245

Maximum speed km/h 170 170 160

Braking Rheostatic Regenerative Rheostatic

Weight tonnes 88 126 126

Axleload tonnes 22 21 21

Overall length mm 16300 22216 22016

Overall width mm 3100 3104 3103

TABLE: Table II. Diesel locomotives

Class DF11 DF4d DF4ck

Wheel arrangement Co-Co Co-Co A1A-A1A

Transmission AC-DC AC-DC AC-DC

Power rating kW 3120 2425 2165

Continuous tractive

effort kN 160 161 126

Starting tractive

effort kN 245 233 167

Maximum speed km/h 170 170 160

Braking Rheostatic Rheostatic Rheostatic

Weight tonnes 138 138 126

Axleload tonnes 23 23 21

Length over

couplers mm 21250 21100 21100

Width mm 3304 3309 3309

TABLE: Table III. Passenger coaches

Type 25Z 25Z 25Z double-deck single-deck single-deck

Length mm 25500 25500 25500

Width mm 3104 3104 3104

Height mm 4750 4050 4050

Seating capacity 108 76 76

Tare weight tonnes 49 43 49·7

Maximum speed km/h 160 160 160

Bogie type 209HS CW-2 SW-160

Braking Disc & tread Disc Disc

TABLE: Table IV. Diesel and electric multiple-units

Class SYZ DMU NZJ1 DMU SF1 DMU KDZ2 EMU DDJ1 EMU double-deck double-deck single-deck single-deck

Formation M+2T+M L+9T+L M+4T+M 3M+3T L+5T+TC

Power plant QST30-G1 12V280ZJ - - -

Transmission AC-DC AC-DC Hydraulic AC-DC AC-DC

Power rating kW 2 x 634 2 x 1980 2 x 1000 2160 4000

Weight tonnes 288 702 372 381 440

Length mm 100650 280000 157244 158600 176000

Seating capacity 530 1140 546 572 436

Maximum speed km/h 100 180 120 120 200

Starting tractive effort kN 2 x 70 2 x 150 190 - 180

Continuous tractive effort kN - 2 x 92 125 - 108

CAPTION: CR has developed the SF1 DMU formed of four single-deck trailers and two power cars with hydraulic transmission

CAPTION: Below left: an SS8 electric locomotive has been tested at 240 km/h

Below: the SS9 Co-Co electric is designed to run at 170 km/h

CAPTION: The 4 800 kW SS7d Bo-Bo-Bo electric loco is designed to haul fast freight trains at a top speed of 160 km/h

CAPTION: Right: The DDJ1 power car is the first to be designed to run at 200 km/h

CAPTION: The 170 km/h DF11 diesel loco has been very successful, with over 100 now in service on inter-city passenger services

CAPTION: The NZJ1 double-deck DMU has two power cars and nine trailers

CAPTION: Inter-city coaches of the 25Z series are designed for 160 km/h. As well as two types of single-deck cars, double-deckers (inset) are increasingly being used to raise capacity

Chinese Railways develops traction to meet market needs

Speeds and tonnages have been steadily rising on the 58000 route-km Chinese Railways (CR) network, and CR has developed a range of electric and diesel locomotives able to handle faster and heavier trains. Prototypes of both electric and diesel multiple-units, some with double-deck coaches, have been put into service, and more are planned in the future. CR is now working on the design of trains able to run at up to 300 km/h, as well as a tilting train using Chinese technology. Further development of locomotives with AC motors and better bogies is envisaged

Les chemins de fer chinois développent la traction pour faire face aux besoins du marché

Les vitesses et les tonnages s'accroissent régulièrement sur les réseau de 58000 km que comptent les chemins de fer chinois; ces derniers ont mis au point un ensemble de locomotives électriques et diesels capables d'assurer des trains plus rapides et plus lourds. Des prototypes d'automotrices électriques et diesels, certaines à deux niveaux, ont été mis en service et d'autres sont envisagés pour l'avenir. Les chemins de fer chinois travaillent à la conception de trains capables de rouler à 300 km/h, ainsi qu'à la création de matériels pendulaires de technologie chinoise. D'autres évolutions touchant les locomotives à motorisation asynchrones et les meilleurs bogies sont également envisagées

Chinesische Eisenbahnen entwickeln marktgerechte Triebfahrzeuge

Geschwindigkeiten und Lasten sind kontinuierlich angestiegen auf dem 58000 Streckenkilometer langen Netz der Chinesischen Eisenbahnen (CR), und die CR haben eine Palette von Elektro- und Diesellokomotiven entwickelt, welche schnellere und schwerere Züge bef