South African Class Experimental AC

{{Short description|Type of electric locomotive}} {{Use dmy dates|date=February 2023}} {{Use South African English|date=August 2013}} {{Infobox locomotive |name = South African Class Experimental AC |image = SAR Class ExpAC E1600 R.JPG |caption = E1600 at Pyramid South, [[Pretoria]] in May 2013 |hatnote = |powertype = Electric |designer = [[Union Carriage & Wagon]] |builder = Union Carriage & Wagon Transwerk |ordernumber = |serialnumber = |buildmodel = UCW 6E1 |builddate = 1978 |totalproduction = 1 |rebuilder = |rebuilddate = |numberrebuilt = |aarwheels = |uicclass = |Britishclass = [[Bo-Bo]] |gauge = {{Track gauge|1067mm|allk=on}} |bogies = |leadingdiameter = |wheeldiameter = {{convert|1.22|m|in|0|abbr=on}} |trailingdiameter = |minimumcurve = |wheelbase = {{convert|11.28|m|ftin|abbr=on}} |bogie = {{convert|3.43|m|ftin|abbr=on}} |pivotcentres = {{convert|7.85|m|ftin|abbr=on}} |pantoshoecentres = |wheelspacing = |length = |over couplers = {{convert|15.49|m|ftin|abbr=on}} |over bufferbeams = |body = {{convert|14.63|m|ftin|abbr=on}} |width = {{convert|2.90|m|ftin|abbr=on}} |height = |pantodown = {{convert|4.29|m|ftin|abbr=on}} |bodyonly = {{convert|3.94|m|ftin|abbr=on}} |frametype = |axleload = {{convert|21.38|tonnes|lb|abbr=on}} |leadingbogie/pony= |weightondrivers = {{convert|85.50|tonnes|lb|abbr=on}} |trail bogie/pony = |locoweight = {{convert|85.50|tonnes|lb|abbr=on}} |sandcap = |electricsystem = [[25 kV 50 Hz AC]] [[Overhead line|catenary]] |collectionmethod = [[Pantograph (transport)|Pantograph]] |alternator = |generator = |tractionmotors = 4 [[Associated Electrical Industries|AEI]] 283AZ |t/m amps 1 hr = {{convert|623|kW|hp|abbr=on}} |t/m amps cont = {{convert|563|kW|hp|abbr=on}} |headendpower = |transmission = |gear ratio = 18:67 |multipleworking = |trainheating = |locobrakes = [[Railway air brake|Air]] |trainbrakes = [[Railway air brake|Air]] & [[Vacuum brake|Vacuum]] |reservoircap = |compressorcap = |exhaustercap = |safety = |coupling = [[Janney coupler|AAR knuckle]] |maxspeed = {{convert|113|km/h|mph|abbr=on}} |poweroutput = |poweroutput start= |poweroutput 1 hr = {{convert|2492|kW|hp|abbr=on}} |poweroutput cont = {{convert|2252|kW|hp|abbr=on}} |tractiveeffort = |t/e starting = {{convert|330|kN|lbf|abbr=on}} |t/e 1 hr = {{convert|218|kN|lbf|abbr=on}} |t/e continuous = {{convert|190|kN|lbf|abbr=on}} |locobrakeforce = |operator = South African Railways Spoornet [[Transnet Freight Rail]] |operatorclass = Class Experimental AC |numinclass = 1 |fleetnumbers = E1600 |officialname = |nicknames = |axleloadclass = |locale = |deliverydate = |firstrundate = 1978 |lastrundate = |withdrawndate = |preservedunits = |restoredate = |scrapdate = |currentowner = |disposition = }}

The '''South African Railways Class Experimental AC''' of 1978 is an electric locomotive.

In 1974 and 1975 the [[Transnet Freight Rail|South African Railways]] placed 100 [[South African Class 6E1, Series 5|Class 6E1, Series 5]] locomotives with a [[Bo-Bo]] wheel arrangement in mainline service. In 1978 one was withdrawn from revenue service for use as an experimental [[25 kV AC railway electrification|25 kV AC locomotive]]. It was rebuilt and reclassified to Class Experimental AC.<ref name=E&Ddiagram-book>South African Railways Index and Diagrams Electric and Diesel Locomotives, 610mm and 1065mm Gauges, Ref LXD 14/1/100/20, 28 January 1975</ref>

==Manufacturer== The 3 kV DC [[South African Class 6E1, Series 5|Class 6E1, Series 5]] electric locomotive was designed and built for the [[South African Railways]] by [[Union Carriage & Wagon]] (UCW) in Nigel, Transvaal.<ref>{{cite web|title=UCW – Electric locomotives|url=http://www.ucw.co.za/pdf/electric_loco.pdf|publisher=The UCW Partnership|access-date=30 September 2010|archive-url=https://web.archive.org/web/20071012023401/http://www.ucw.co.za/pdf/electric_loco.pdf|archive-date=12 October 2007}}</ref>

==Orientation== These dual cab locomotives have a roof access ladder on one side only, just to the right of the cab access door. The roof access ladder end is marked as the no. 2 end. A corridor along the centre of the locomotive connects the cabs.<ref name=E&Ddiagram-book/>

==Test bed for 25 kV AC research== In 1978, E1600 was withdrawn from revenue service and rebuilt as a test-bed for use during 25 kV AC electrification and reclassified to the sole Class Experimental AC. It was used for testing to detect and eliminate potential problems during the electrification of the four isolated 25 kV networks. These networks are:<ref name=E&Ddiagram-book/><ref name=Paxton-Bourne>{{Paxton-Bourne|pages=128-129, 136}}</ref><ref>{{Middleton-SA Loco Guide|pages=50-51, 60}}</ref> *Pyramid South to [[Pietersburg]] and via [[Rustenburg]] to [[Thabazimbi]] *[[Ermelo, Mpumalanga|Ermelo]] to [[Richards Bay]] *[[Port Elizabeth]] via [[Noupoort]] to [[De Aar]] and from there northward to [[Kimberley, Northern Cape|Kimberley]] and southward to [[Beaufort West]] *[[East London, South Africa|East London]] to [[Springfontein]]

The unit's single [[Pantograph (rail)|pantograph]] and its electronic and electric equipment were manufactured by the 50 c/s Group, a consortium consisting of [[Ateliers de Constructions Electriques de Charleroi|ACEC]] of Belgium, [[AEG (German company)|AEG-Telefunken]] and [[Siemens Mobility|Siemens]] of Germany, [[Alstom|Alsthom-Atlantique]] and Société MTE of France, and [[Brown, Boveri & Cie|Brown Boveri]] of Switzerland. The same consortium also designed the 25 kV AC [[South African Class 7E|Class 7E]] locomotives which were placed in service on the four 25 kV networks.<ref name=Paxton-Bourne/>

The vacuum circuit breaker was supplied by GEC. The original Class 6E1 AEI-283AZ traction motors, manufactured by [[Associated Electrical Industries]], were retained and the locomotive used a thyristor-diode rectifier set for the traction motor DC power supply. Mechanical components were supplied by UCW.<ref name=E&Ddiagram-book/><ref name=Paxton-Bourne/>

Apart from the inscriptions painted on the locomotive sides, the Class Experimental AC locomotive can be visually distinguished from regular Class 6E1 locomotives by the single pantograph on its no. 2 end instead of the usual two pantographs, one on each end, as well as by the large grilles on the sides. The Class 6E1 has two large grilles to the right of centre on each side while no. E1600 has only one such grille on the roof access ladder side and three on the opposite side.<ref name=Paxton-Bourne/>

==References== {{Reflist}}

==External links== {{commons category-inline|South African Class Exp/AC|South African Class Experimental AC}}

[[Category:Bo-Bo locomotives]] [[Category:25 kV AC locomotives]] [[Category:Cape gauge railway locomotives]] [[Category:Electric locomotives of South Africa]] [[Category:Individual locomotives of South Africa]] [[Category:Railway locomotives introduced in 1978]] [[Category:Transnet Rail Engineering locomotives]] [[Category:Union Carriage & Wagon locomotives]]