South African Class 21E

The South African Class 21E of 2015 is a South African electric locomotive from the Transnet Freight Rail era.

On 16 September 2014 the first of the Class 21E dual voltage electric locomotives for Transnet Freight Rail was rolled out at the CSR Zhuzhou Electric Locomotive Company in China. Two of these locomotives were built in China with another 38 to follow, while the rest will be built locally.^[1][2][3]

Manufacturer

The first forty of the one hundred 3 kV DC and 25 kV AC dual voltage Class 21E electric locomotives for Transnet Freight Rail were built in China by Zhuzhou Electric Locomotive Company, a subsidiary of the China South Locomotive and Rolling Stock Corporation (CSR), China's leading train manufacturer.^[1] The roll-out ceremony of the first locomotive, no. 21-001, took place at the factory on 16 September 2014. The remaining sixty locomotives of the order will be built in South Africa.^[2][3][4]

According to the project plan, the agreement also included the joint production of more electric locomotives, electric multiple units, suburban rail vehicles and rail transportation equipment for South Africa and the African region.^[1][2][3][4]

The first two locomotives were delivered for acceptance trials on 11 December 2014. They came ashore at Maydon Wharf in Durban and were moved dead in tow to Pyramid South Depot north of Pretoria the following day. No. 21-002 was equipped with load-measuring-wheelsets, painted yellow, on its front bogie.

Characteristics

The Class 21E is virtually identical in visual appearance to the earlier Class 20E locomotive, which was described by the manufacturer as the "promotion version" of the Class 21E. It is in essence an upgraded version of the Class 20E, based on customer requirements. It is a heavier locomotive with the axle load increased to 26,000 kilograms (26 long tons) and with improved tractive effort to make it more suitable for service on the Coalink line. It makes use of more advanced Electronically Controlled Pneumatic (ECP) brake system technology to control the train's air brakes through electrical signals, which improves the train's braking response time and results in improved safety and reliability. The four-axle locomotive is capable of an output of 3,000 kilowatts (4,023 horsepower) and a speed of 100 kilometres per hour (62 miles per hour). Its microcomputer network control system allows eight of these locomotives to work together in a multi-unit consist and also to work consisted to diesel-electric locomotives.^[1][2][3]

The only externally visible differences between the Classes 20E and 21E are on the pilots and the left side of the cab roof.

• The Class 20E has two cable sockets on each side of the coupler and a fifth socket in a cut-out on the sill, below the front door on the front pilot and in the same position on the rear pilot, near the right end of the sill. The Class 21E has no cut-out in the sill and instead of the two pairs of cable sockets, it has a rectangular box on each side of the coupler. These boxes are radio frequency distributed power (RFDP) conjunction boxes which are also present on the Class 20E, where it is located behind the cowcatchers.
• The Class 21E has a small rectangular grille near the rear end of the left side of the cab roof and above the large grilled hatch door to the right of the cab door on the left side. This small grille is absent on the Class 20E.^[5]

The locomotive body is a welded monocoque design, constructed of steel plates and profiled members, that has a compressive strength of 4.45 meganewtons (1,000,000 pounds-force) and a tensile strength of 4 meganewtons (900,000 pounds-force). The Class 21E has a single cab and a gangway along the centre of the locomotive. It is equipped with a wireless data transmission system which can send the locomotive operation status, fault data and energy consumption data via GSM and Wi-Fi to a trackside station for analysis. It is also equipped with an axle temperature alarm device, fire alarm system, closed-circuit television (CCTV) system, wheel flange lubricating device and, as personnel safety measure, high voltage protective interlocking devices. The AC traction motors are powered through insulated-gate bipolar transistor (IGBT) control.^[6]

As on the dual voltage Classes 19E and 20E, the main electric circuit is automatically selected in either AC or DC mode, based on the voltage of the overhead contact wire feeding the locomotive. To facilitate automatic trouble-free transition on the run, the locomotive is equipped with onboard voltage detectors, while the overhead wire is equipped with two wooden isolators and a 3 metres (10 feet) length of neutral wire to separate the AC and DC feeds. The neutral section is connected to the rails, which serve as the return conductor on electrified lines.^[6]

The transition process requires that the locomotive be switched off automatically before it reaches the isolators and the unpowered overhead wire section, and automatically restarted after exiting from under the unpowered wire. This is done by a pair of track magnets, one on either side of the neutral overhead wire and spaced 45 metres (148 feet) apart. The two magnets are mounted with their polarities reversed in relation to each other and they activate a magnetic relay, located behind the cowcatcher of the locomotive, to do the switching off and restarting.^[6]

Service

The Class 21E is intended for the 25 kV AC Coalink line between Ermelo and the Richards Bay Coal Terminal.^[2][3] They will also work directly from the coal mines around Ermelo, running under 3 kV DC electrification. Like the Class 19E, the dual voltage Class 21E locomotives can therefore haul their loads directly from the mines all the way to Richards Bay without having to change locomotives in Ermelo to cater for the change in the power supply.

Gallery

• 

  No. 21-002 in Durban Docks upon arrival from China, with yellow wheels on the front bogie, 11 December 2014

• 

  No. 21-001 and 21-002 dead in tow en route to Pyramid South, Pretoria on 12 December 2014

See also

• Electric locomotive numbering and classification
• List of South African locomotive classes
• South African locomotive history

References

Locomotives of South Africa Steam Brunel gauge HBEL 0-4-0 HBTB 0-4-0T HBTB 0-4-0WT HBTB 0-4-0ST Broad gauge CGR Aid CGR Blackie CGR 0-4-2 CGR 2-4-0T NRC Durban NRC Natal NRC Perseverance Cape gauge Tank CGR Coffee Pot CGR 040 1873 CGR 040 1874 CGR 060 1876 CGR 060 1902 CGR 260 1900 CGR 260 1902 CGR 1st 040 1875 CGR 1st 440 1875 CGR 1st 040 1876 CGR 1st 260 1876 CGR 2nd 1882 CGR 3rd 1900 CGR RM CSAR C CSAR E CSAR Rack CSAR RM Dbn Congella Dbn Edward Innes Dbn John Milne Dbn Sir Albert HBPE 040 Kowie 060 Kowie 440 M&S 462 NGR Dbn & Pmb NGR I 262 NGR K 040 NGR K 060 NGR K 260 NZASM 10T NZASM 14T NZASM 18T NZASM 19T NZASM 32T NZASM 40T PPR 26T PPR 35T SAR RM SAR 0-4-0ST SAR 040 69 SAR A SAR B SAR C SAR C1 SAR C2 SAR D SAR E SAR F SAR G SAR H SAR H1 SAR H2 SAR J SAR K SWA 2-8-0T Cape gauge Tender CGR 1st 260 1876 BP CGR 1st 260 1876 K CGR 1st 260 1879 CGR 1st 440 1879 CGR 1st 1881 CGR 1st 1891 CGR 2nd 1875 CGR 3rd 1883 CGR 3rd 1884 CGR 3rd 1889 CGR 3rd 1898 CGR 3rd 1901 CGR 3rd 1903 CGR 4th 1880 CGR 4th 1882 CGR 4th 1884 CGR 4th 1897 CGR 5th 1890 CGR 5th 1891 NGR Havelock NGR I 260 Exp-1 Exp-2 Exp-3 Exp-4 Exp-5 Exp-6 SAR S SAR S1 SAR S2 SAR 1 SAR 1A SAR 1B SAR 2 SAR 2C SAR 3 SAR 3A SAR 3B SAR 4 SAR 4A SAR 5 SAR 5A SAR 5B SAR 6 SAR 6A SAR 6B SAR 6C SAR 6D SAR 6E SAR 6F SAR 6G SAR 6H SAR 6J SAR 6K SAR 6L SAR 6Y SAR 6Z SAR 7 SAR 7A SAR 7B SAR 7C SAR 7D SAR 7E SAR 7F SAR 8 SAR 8A SAR 8B SAR 8C SAR 8D SAR 8E SAR 8F SAR 8X SAR 8Y SAR 8Z SAR 9 SAR 10 SAR 10A SAR 10B SAR 10C SAR 10D SAR 11 SAR 12 SAR 12A SAR 12B SAR 13 SAR 14 SAR 14A SAR 14B SAR 14C SAR 15 SAR 15A SAR 15B SAR 15C SAR 15CA SAR 15E SAR 15F SAR 16 SAR 16A SAR 16B SAR 16C SAR 16D SAR 16DA SAR 16E SAR 17 SAR 18 SAR 19 SAR 19A SAR 19B SAR 19C SAR 19D SAR 20 SAR 21 SAR 23 SAR 24 SAR 25 SAR 25NC SAR 26 SWA 2-8-0 Cape gauge Articulated CGR Fairlie CGR Kitson-Meyer SAR FC SAR FD SAR GA SAR GB SAR GC SAR GCA SAR GD SAR GDA SAR GE SAR GEA SAR GF SAR GG SAR GH SAR GK SAR GL SAR GM SAR GMA SAR GO SAR HF SAR KM SAR MA SAR MB SAR MC SAR MC1 SAR MD SAR ME SAR MF SAR MG SAR MH SAR MJ SAR MJ1 SAR U 2ft 6in gauge CCC 1871 CCC Britannia CCC Caledonia CCC Clara CCC Condenser CCC Scotia NCC Pioneer 2ft & 600mm gauges ACR NG-G16A CGR NG 060 CGR NG 462 CGR A CGR C NGR N SAR 040 1899 SAR NG1 SAR NG2 SAR NG3 SAR NG4 SAR NG5 SAR NG6 SAR NG7 SAR NG8 SAR NG9 SAR NG10 SAR NG-G11 SAR NG-G12 SAR NG-G13 SAR NG-G14 SAR NG15 SAR NG-G16 SWA Ha SWA Hb SWA Hc SWA Hd SWA Jung SWA Zwillinge Diesel -electric SAR DS SAR DS1 SAR 31-000 SAR 32-000 SAR 32-200 SAR 33-000 SAR 33-200 SAR 33-400 SAR 34-000 SAR 34-200 SAR 34-400 SAR 34-500 SAR 34-600 SAR 34-800 SAR 34-900 SAR 35-000 SAR 35-200 SAR 35-400 SAR 35-600 SAR 36-000 SAR 36-200 SAR 37-000 SN 39-000 TFR 39-200 TFR 43-000 SAR 91-000 Afro4000 -hydraulic SAR 61-000 Electro-diesel SN 38-000 Electric SAR ES SAR ES1 Exp-AC SAR 1E SAR 2E SAR 3E SAR 4E SAR 5E-S1 SAR 5E-S2 SAR 5E-S3 SAR 5E1-S1 SAR 5E1-S2 SAR 5E1-S3 SAR 5E1-S4 SAR 5E1-S5 SAR 6E SAR 6E1-S1 SAR 6E1-S2 SAR 6E1-S3 SAR 6E1-S4 SAR 6E1-S5 SAR 6E1-S6 SAR 6E1-S7 SAR 6E1-S8 SAR 6E1-S9 SAR 6E1-S10 SAR 6E1-S11 SAR 7E SAR 7E1 SAR 7E2-S1 SAR 7E2-S2 SAR 7E3-S1 SAR 7E3-S2 SN 7E4 SAR 8E SAR 9E-S1 SAR 9E-S2 SAR 10E SAR 10E1-S1 SAR 10E1-S2 SAR 10E2 SAR 11E SAR 12E SN 14E SN 14E1 TFR 15E SN 16E SN 17E SN 18E-S1 TFR 18E-S2 TFR 19E TFR 20E TFR 21E E38 List of South African locomotive classes Rail transport in South Africa