{{Short description|1935 design of steam locomotive}} {{Use dmy dates|date=December 2013}} {{Use South African English|date=December 2013}} {{Infobox locomotive | name = South African Class 20 2-10-2 | image = SAR Class 20 2485 (2-10-2) Condenser.jpg | alt = | caption = No. 2485 as experimental condenser, c. 1950 | hatnote = ♠ [[South African type MP1 tender|Type MP1 tender]] - {{font color|red|♥}} [[South African type MT2 tender|Type MT2 tender]]<br>{{font color|blue|♣}} [[South African type CL tender|Type CL condensing tender]] | powertype = Steam | designer = [[South African Railways]]<br>(A.G. Watson) | builder = South African Railways | ordernumber = | serialnumber = | buildmodel = Class 20 | builddate = 1935 | totalproduction = 1 | rebuilder = South African Railways | rebuilddate = 1950 | numberrebuilt = 1 to condensing locomotive | whytetype = [[2-10-2]] (Santa Fe) | uicclass = 1'E1'h2 | driver = 3rd coupled axle | gauge = {{Track gauge|Cape|allk=on}} | leadingdiameter = {{convert|28+1/2|in|mm|0|abbr=on}} | coupleddiameter = {{convert|48|in|mm|0|abbr=on}} | trailingdiameter = {{convert|34|in|mm|0|abbr=on}} | tenderdiameter = ♠{{font color|red|♥}}{{font color|blue|♣}} {{convert|34|in|mm|0|abbr=on}} | minimumcurve = | wheelbase = ♠ {{convert|59|ft|6+1/8|in|mm|0|abbr=on}}<br>{{font color|blue|♣}} {{convert|77|ft|8+7/8|in|mm|0|abbr=on}} | engine total = {{convert|31|ft|7+1/2|in|mm|0|abbr=on}} | leading = | coupled = {{convert|17|ft|mm|0|abbr=on}} | trailing = | tender total = ♠ {{convert|16|ft|9|in|mm|0|abbr=on}}<br>{{font color|red|♥}} {{convert|20|ft|5|in|mm|0|abbr=on}}<br>{{font color|blue|♣}} {{convert|33|ft|5|in|mm|0|abbr=on}} | tenderbogie = ♠ {{convert|4|ft|7|in|mm|0|abbr=on}}<br>{{font color|red|♥}} {{convert|6|ft|2|in|mm|0|abbr=on}}<br>{{font color|blue|♣}} {{convert|8|ft|8|in|mm|0|abbr=on}} | pivotcentres = | wheelspacing = | length = | over couplers = ♠ {{convert|68|ft|1|in|mm|0|abbr=on}}<br>{{font color|blue|♣}} {{convert|88|ft|5+1/2|in|mm|0|abbr=on}} | over bufferbeams= | width = | height = {{convert|12|ft|11+1/4|in|mm|0|abbr=on}} | frametype = [[Locomotive frame#Bar frames|Bar]] | axleload = ♠{{font color|red|♥}} {{convert|11|lt|14|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|blue|♣}} {{convert|13|lt|kg|sigfig=4|abbr=on}} | leadingbogie/pony= ♠{{font color|red|♥}} {{convert|8|lt|2|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|blue|♣}} {{convert|9|lt|5|lcwt|kg|sigfig=4|abbr=on}} | coupled all = | coupled 1 = ♠{{font color|red|♥}} {{convert|11|lt|6|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|blue|♣}} {{convert|12|lt|16|lcwt|kg|sigfig=4|abbr=on}} | coupled 2 = ♠{{font color|red|♥}} {{convert|11|lt|10|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|blue|♣}} {{convert|13|lt|kg|sigfig=4|abbr=on}} | coupled 3 = ♠{{font color|red|♥}} {{convert|11|lt|14|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|blue|♣}} {{convert|11|lt|12|lcwt|kg|sigfig=4|abbr=on}} | coupled 4 = ♠{{font color|red|♥}} {{convert|11|lt|4|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|blue|♣}} {{convert|11|lt|12|lcwt|kg|sigfig=4|abbr=on}} | coupled 5 = ♠{{font color|red|♥}} {{convert|11|lt|3|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|blue|♣}} {{convert|11|lt|12|lcwt|3|qtr|kg|sigfig=4|abbr=on}} | coupled 6 = | coupled 7 = | coupled 8 = | trail bogie/pony= ♠{{font color|red|♥}} {{convert|8|lt|18|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|blue|♣}} {{convert|9|lt|9|lcwt|1|qtr|kg|sigfig=4|abbr=on}} | tenderbogieload = '''Bogie 1:'''<br>♠ {{convert|27|lt|10|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|red|♥}} {{convert|33|lt|18|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|blue|♣}} {{convert|41|lt|13|lcwt|1|qtr|kg|sigfig=4|abbr=on}}<br>'''Bogie 2:'''<br>♠ {{convert|23|lt|11|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|red|♥}} {{convert|35|lt|10|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|blue|♣}} {{convert|37|lt|3|lcwt|1|qtr|kg|sigfig=4|abbr=on}} | tenderaxle = ♠ {{convert|13|lt|15|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|red|♥}} {{convert|17|lt|15|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|blue|♣}} {{convert|13|lt|17|lcwt|3|qtr|kg|sigfig=4|abbr=on}} | weightondrivers = ♠{{font color|red|♥}} {{convert|56|lt|17|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|blue|♣}} {{convert|60|lt|12|lcwt|3|qtr|kg|sigfig=4|abbr=on}} | locoweight = ♠{{font color|red|♥}} {{convert|73|lt|7|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|blue|♣}} {{convert|79|lt|7|lcwt|kg|sigfig=4|abbr=on}} | tenderweight = ♠ {{convert|51|lt|1|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|red|♥}} {{convert|69|lt|8|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|blue|♣}} {{convert|78|lt|16|lcwt|kg|sigfig=4|abbr=on}} | locotenderweight = ♠ {{convert|124|lt|8|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|red|♥}} {{convert|142|lt|15|lcwt|kg|sigfig=4|abbr=on}}<br>{{font color|blue|♣}} {{convert|158|lt|3|lcwt|kg|sigfig=4|abbr=on}} | tendertype = ♠ [[South African type MP1 tender|MP1 (2-axle bogies)]]<br>{{font color|red|♥}} [[South African type MT2 tender|MT2 (2-axle bogies)]]<br>{{font color|blue|♣}} [[South African type CL tender|CL (Buckeye 3-axle bogies)]]<br>CL, MP1, MT2, [[South African type MX tender|MX]], [[South African type MY tender|MY]] permitted | fueltype = Coal | fuelcap = ♠ {{convert|10|lt|t|1|abbr=on}}<br>{{font color|red|♥}} {{convert|14|lt|t|1|abbr=on}}<br>{{font color|blue|♣}} {{convert|11|lt|10|lcwt|t|1|abbr=on}} | watercap = ♠ {{convert|4250|impgal|L|sigfig=3|abbr=on}}<br>{{font color|red|♥}} {{convert|6000|impgal|L|sigfig=3|abbr=on}}<br>{{font color|blue|♣}} {{convert|3900|impgal|L|sigfig=3|abbr=on}} | tendercap = | sandcap = | fireboxtype = Round-top | firearea = {{convert|36|sqft|m2|abbr=on}} | boiler = | boilertype = | pitch = {{convert|8|ft|mm|0|abbr=on}} | diameterinside = {{convert|4|ft|10+1/4|in|mm|0|abbr=on}} | lengthinside = {{convert|20|ft|3/8|in|mm|0|abbr=on}} | smalltubediameter= '''86:''' {{convert|2+1/4|in|mm|0|abbr=on}} | largetubediameter= '''18:''' {{convert|5+1/2|in|mm|0|abbr=on}} | boilerpressure = {{convert|200|psi|kPa|0|abbr=on}} | safetyvalvetype = [[Safety valve#"Pop" valves|Pop]] | feedwaterheater = | totalsurface = {{convert|1667|sqft|m2|abbr=on}} | tubearea = {{convert|1527|sqft|m2|abbr=on}} | archarea = {{convert|15|sqft|m2|abbr=on}} | fluearea = | tubesandflues = | fireboxarea = {{convert|125|sqft|m2|abbr=on}} | superheatertype = | superheaterarea = {{convert|415|sqft|m2|abbr=on}} | generator = | cylindercount = Two | cylindersize = {{convert|21|in|mm|0|abbr=on}} bore<br>{{convert|24|in|mm|0|abbr=on}} stroke | frontcylindersize= | rearcylindersize = | hpcylindersize = | lpcylindersize = | valvegear = Rotary cam | valvetype = [[Poppet valve#Steam engine|Poppet]] | valvetravel = | valvelap = | valvelead = | transmission = | trainheating = | locobrakes = | trainbrakes = | safety = | coupling = [[Janney coupler|AAR knuckle]] | maxspeed = | poweroutput = | tractiveeffort = {{convert|33080|lbf|kN|abbr=on}} @ 75% | factorofadhesion = | locobrakeforce = | operator = South African Railways | operatorclass = Class 20 | powerclass = | numinclass = 1 | fleetnumbers = 2485 | officialname = ''Pretoria'' | nicknames = ''Trapsuutjies'' | axleloadclass = | deliverydate = 1935 | firstrundate = 1935 | lastrundate = | withdrawndate = 1958 | preservedunits = | restoredate = | scrapdate = 1961 | currentowner = | disposition = | notes = The 3rd & 4th coupled axles had flangeless wheels }}
The '''South African Railways Class 20 2-10-2''' of 1935 was a steam locomotive.
In 1935, the South African Railways placed one Class 20 steam locomotive with a {{nowrap|[[2-10-2]]}} Santa Fe type wheel arrangement in service, designed and built at its Pretoria Mechanical Shops. In 1950, it was modified to an experimental condensing locomotive.<ref name="Holland 2">{{Holland-Vol 2|pages=71, 107}}</ref><ref name="SAR&H Aug 1946">Espitalier, T.J.; Day, W.A.J. (1946). ''The Locomotive in South Africa - A Brief History of Railway Development. Chapter VII - South African Railways (Continued).'' South African Railways and Harbours Magazine, August 1946. pp. 630-631.</ref><ref name="Paxton-Bourne">{{Paxton-Bourne|pages=10-11, 73-74}}</ref><ref name="Espitalier">Espitalier, T.J. (1947). ''Locomotives Designed and Built in South Africa - The S1, in service this month, is not the first locally-built engine.'' South African Railways and Harbours Magazine, October 1947. pp. 841-843.</ref>
The Class 20 was the third locomotive type to be designed and built in South Africa, after the [[NGR 4-6-2TT Havelock|Natal Government Railways 4-6-2TT ''Havelock'' of 1888]] and the [[South African Class 2C 4-6-2|Class 2C of 1910]].<ref name="Espitalier"/>
==Construction== The Class 20 2-10-2 Santa Fe type steam locomotive was designed in 1934 by A.G. Watson, Chief Mechanical Engineer of the South African Railways (SAR) from 1929 to 1936, and was built by the SAR at its Pretoria Mechanical Shops at Salvokop. The locomotive was intended for use on the South West Africa system, where the tracks consisted of {{convert|40+1/4|lb/yd|kg/m|0|abbr=off}} section rail laid in desert conditions and practically without ballast. This restricted Watson to a maximum axle load of {{convert|11|lt|t|1|abbr=off}} and he decided upon a Santa Fe type wheel arrangement with {{convert|48|in|mm|0|abbr=off|adj=on}} diameter coupled wheels and flangeless driving and intermediate coupled wheels.<ref name="SAR&H Aug 1946"/><ref name="Paxton-Bourne"/><ref name="Espitalier"/><ref name="Diagram-book 1">South African Railways & Harbours/Suid Afrikaanse Spoorweë en Hawens (15 Aug 1941). ''Locomotive Diagram Book/Lokomotiefdiagramboek, 3'6" Gauge/Spoorwydte''. SAR/SAS Mechanical Department/Werktuigkundige Dept. Drawing Office/Tekenkantoor, Pretoria. pp. VIII, 45.</ref><ref name="Diagram-book 2">South African Railways & Harbours/Suid Afrikaanse Spoorweë en Hawens (15 Aug 1941). ''Locomotive Diagram Book/Lokomotiefdiagramboek, 2'0" & 3'6" Gauge/Spoorwydte, Steam Locomotives/Stoomlokomotiewe''. SAR/SAS Mechanical Department/Werktuigkundige Dept. Drawing Office/Tekenkantoor, Pretoria. pp. VIII, 6a-7a, 28, 45.</ref>
[[File:A.G. Watson.jpg|thumb|left|150px|A.G. Watson]] The sole Class 20 locomotive was numbered 2485. It was a hybrid, with a boiler which had been inherited from a [[South African Class 19A 4-8-2|Class 19A]] locomotive which had been equipped with a [[South African locomotive numbering and classification#Watson Standard boilers|Watson Standard no. 1A boiler]]. The driving wheels were from scrapped [[South African Class 8 4-8-0|Class 8]] locomotives. The trailing pony truck was similar to that of the Class 19C, but the leading [[Bissel truck]] was specially designed. The bar frames and cylinders were imported.<ref name="Holland 2"/><ref name="SAR&H Aug 1946"/><ref name="Paxton-Bourne"/>
Even though it was not wholly a South African product with its imported frames and cylinders and its inherited boiler from a Swiss-built locomotive, this was the third recorded instance of steam locomotives designed and constructed in South African workshops after the Natal Government Railways' engine ''Havelock'' of 1888 and the Class 2C of 1910.<ref name="SAR&H Aug 1946"/><ref name="Espitalier"/><ref name="SAR&H Jun 1944">Espitalier, T.J.; Day, W.A.J. (1944). ''The Locomotive in South Africa - A Brief History of Railway Development. Chapter III - Natal Government Railways''. (Continued). South African Railways and Harbours Magazine, June 1944. pp. 421-422.</ref><ref name="SAR&H Aug 1944">Espitalier, T.J.; Day, W.A.J. (1944). ''The Locomotive in South Africa - A Brief History of Railway Development. Chapter III - Natal Government Railways'' (Continued). South African Railways and Harbours Magazine, August 1944. p. 599.</ref>
==Characteristics== The cylinders, with [[Poppet valve#Steam engine|rotary cam poppet]] valve gear, were identical to those of the [[South African Class 19C 4-8-2|Class 19C]] but with the stroke reduced from {{convert|26|in|mm|0|abbr=off}} to {{convert|24|in|mm|0|abbr=off}}. The modified cylinder covers had deep spigots to suit the reduction in stroke. The main drive and valve gear drive was from the third pair of coupled wheels. Grease lubrication was provided for all coupled wheel axle boxes. The ten-coupled wheel arrangement, in conjunction with the sharp curvature of the lines in South West, necessitated special side play for the leading coupled wheel axle boxes and spherical bearings for the leading crank pins.<ref name="SAR&H Aug 1946"/><ref name="Espitalier"/>
The design of the leading Bissel truck necessitated certain proportions to suit the ten-coupled wheel arrangement, but the trailing [[Bissel truck]] was similar to that of the Class 19C. Its axle boxes were provided with end thrust pad bearings attached to the axle box covers, which relieved the ends of the bearing from the effects of end thrust. This device proved successful in reducing the number of hot boxes on trailing Bissels.<ref name="SAR&H Aug 1946"/>
The locomotive was tended by a [[South African type MP1 tender|Type MP1 tender]] with a {{convert|10|lt|t|1|abbr=off}} coal capacity, a {{convert|4250|impgal|L|sigfig=3|abbr=off}} water capacity and a {{convert|13|lt|15|lcwt|kg|sigfig=4|abbr=off}} axle load. The total weight of the engine and tender in full working order was {{convert|124|lt|8|lcwt|kg|sigfig=4|abbr=off}}.<ref name="SAR&H Aug 1946"/>
Watson disliked articulated locomotives and his aim with the Class 20 was to build an as powerful as possible non-articulated locomotive with a maximum {{convert|12|lt|t|1|abbr=off}} axle load. The resulting Class 20 could be considered as Watson's answer to the [[South African Class GCA 2-6-2+2-6-2|Class GCA]] Garratt locomotive which had very similar weight and tractive effort capacities. The Class 20 carried more water and coal than the Garratt and was about {{convert|20|lt|t|1|abbr=off}} heavier with {{convert|33080|lbf|kN|1|abbr=off}} tractive effort compared to the {{convert|28470|lbf|kN|1|abbr=off}} of the Class GCA. Even so, only one Class 20 was produced and the design was not repeated.<ref name="SAR&H Aug 1946"/><ref name="Paxton-Bourne"/><ref name="Durrant">{{Durrant-Twilight|pages=63-64}}</ref>
The construction of this sole Class 20 locomotive marked the beginning of a research process which was continued two years later with the construction of the sole [[South African Class 21 2-10-4|Class 21 2-10-4]] and which eventually culminated in the procurement of the [[South African Class 23 4-8-2|Class 23 4-8-2]] fleet in 1939.<ref name="Diagram-book 1"/><ref name="Diagram-book 2"/><ref name="Durrant"/>
==Service== The locomotive was intended for goods traffic on light rail in [[South West Africa]], even though freight traffic volumes in that territory were hardly enough to justify such a powerful engine. It was sent to various branches in the Eastern Transvaal to undergo tests before it entered service in South West Africa, but after some evidence that the engine was rather severe on the light track, it was returned to South Africa after comparatively short service. It was then allocated to [[Pretoria]] for working on the Eastern Transvaal System where its power capacity could be used more productively.<ref name="Holland 2"/><ref name="SAR&H Aug 1946"/><ref name="Paxton-Bourne"/><ref name="Soul of a Railway 8-2">[https://sites.google.com/site/soulorailway/home/system-8/pretoria-local-services-locomotive-sheds-and-workshops---2 Soul of A Railway, System 8, Part 2: Pretoria: including local services, workshops and running sheds, Part 2. Captions 4 to 9.] {{Webarchive|url=https://web.archive.org/web/20170325113112/https://sites.google.com/site/soulorailway/home/system-8/pretoria-local-services-locomotive-sheds-and-workshops---2 |date=25 March 2017 }} (Accessed on 18 March 2017)</ref>
Photographs show that, after being returned to Pretoria, the engine's Type MP1 tender was replaced by a larger [[South African type MT2 tender|Type MT2 tender]] with a {{convert|14|lt|t|1|abbr=off}} coal capacity, a {{convert|6000|impgal|L|sigfig=3|abbr=off}} water capacity and a {{convert|17|lt|15|lcwt|kg|sigfig=4|abbr=off}} axle load. The total weight of the engine and Type MT2 tender in full working order was {{convert|142|lt|15|lcwt|kg|sigfig=4|abbr=off}}. The Pretoria enginemen considered the Class 20 to be one of their best locomotives since it was free-steaming, more than usually trouble-free and able to handle any load they gave it.<ref name="Holland 2"/>
==Condensing trials== The arid nature of a large part of South Africa and the consequent difficulty to ensure adequate and suitable water supplies for steam locomotives led to a decision to experiment with condensing locomotives. Such locomotives had by then already been built by [[Henschel & Son|Henschel and Son]] for use in [[Argentina]], 240 ''Kriegsloks'' for the Eastern Front in [[Germany]] in the 1930s and more than 4,000 units of the Russian SO<sup>K</sup> class, mainly for use in [[Turkestan]] and other arid regions of the Soviet Union. In the pre-war years, the SAR considered modifying a [[South African Class 12A 4-8-2|Class 12A]] into a condensing locomotive, but this never happened.<ref name="Paxton-Bourne"/><ref name="Soul of a Railway 1-4">[https://sites.google.com/site/soulorailway/home/system-1/soul-of-a-railway-system-1-part-4-touws-river-beaufort-west-by-cp-lewis Soul of A Railway, System 1, Part 4: Touws River to Beaufort West Introduction, Caption 6.] (Accessed on 27 November 2016)</ref>
[[File:Buckeye bogie.jpg|thumb|left|Buckeye bogie]] In 1950, the Class 20 was modified to an experimental condensing locomotive in the Pretoria workshops, fitted with German ''Witte''-style smoke deflectors, an extension to the chimney and a [[South African type CL tender|Type CL condensing tender]] which had been ordered from Henschel in 1948. This condensing tender, with Henschel works no. T28388, was designed for a [[Deutsche Reichsbahn]] [[DRB Class 52|Class 52]] condensing locomotive. It was modified slightly and was equipped with a pair of Buckeye three-axle bogies instead of the German arrangement of one six-wheeled and one four-wheeled bogie. It had an {{convert|11|lt|t|1|abbr=off}} coal capacity, a {{convert|3900|impgal|L|sigfig=3|abbr=off}} water capacity and a {{convert|13|lt|17|lcwt|3|qtr|kg|sigfig=4|abbr=off}} axle load. The total weight of the modified engine and Type CL tender in full working order was {{convert|158|lt|3|lcwt|kg|sigfig=4|abbr=off}}.<ref name="Holland 2"/><ref name="Paxton-Bourne"/><ref name="Soul of a Railway 8-2"/><ref name="Soul of a Railway 1-4"/><ref name="Soul of a Railway 8-1">[https://sites.google.com/site/soulorailway/home/system-8/part-1-pretoria-local-services-workshops-and-running-sheds Soul of A Railway, System 8, Part 1: Pretoria: including local services, workshops and running sheds, Part 1. Caption 25.] {{Webarchive|url=https://web.archive.org/web/20170319200012/https://sites.google.com/site/soulorailway/home/system-8/part-1-pretoria-local-services-workshops-and-running-sheds |date=19 March 2017 }} (Accessed on 15 March 2017)</ref><ref name="Henschel">Henschel & Son works list, compiled by Dietmar Stresow</ref><ref name="Kondenslok">[http://kondenslok.de/frame.htm?/vor_sa1.htm Ein Chamäleon als Wegbereiter für die Karoo-Kamele] (Accessed on 6 June 2016)</ref>
The Type CL tender was designed in such a way that it could also be used on a modified [[South African Class 19D 4-8-2|Class 19D]] or [[South African Class 24 2-8-4|Class 24]], but this was never done. The tender was capable of condensing {{convert|27000|lb|kg|abbr=off}} of exhaust steam per hour in maximum operating temperatures of between {{convert|100|and|110|F|C|abbr=off}}. As on the later Class 25 condensing locomotives, the pipe to feed spent steam back to the condensing tender was mounted on the left side of the engine. It was run back from the smokebox above the running board to a box that contained a centrifuge and filters to remove cylinder lubricant from the exhaust steam, then below the running board and underneath the cab to the tender. The tender had six large radiators on each side, cooled by three exhaust steam-driven roof-mounted fans which drew air from outside through the radiators.<ref name="Holland 2"/><ref name="Paxton-Bourne"/><ref name="Soul of a Railway 8-2"/>
Beginning in 1951, tests with the condensing Class 20, named ''Pretoria'', were conducted in the Eastern Transvaal and the [[Karoo]]. It proved the viability of condensing locomotives in [[South Africa]] by attaining a saving of between 88% and 93% on water as well as a lower coal consumption, the latter brought about by the higher temperature of the condensed feedwater. Depending on the operating conditions, a water range of between {{convert|400|and|680|mi|km|abbr=off}} was achieved.<ref name="Holland 2"/><ref name="Paxton-Bourne"/><ref name="Soul of a Railway 8-2"/>
At the end of 1951, the locomotive was relocated to [[Touws River (town)|Touws River]] where it was used for further condensing tests and occasionally put to work in regular service. The positive results of the condensing trials led to the introduction of the [[South African Class 25 4-8-4|Class 25]] condensing locomotive fleet in 1953.<ref name="Holland 2"/><ref name="Paxton-Bourne"/><ref name="Kondenslok"/>
At that time, no. 2485 was again relocated, this time to [[De Aar]] for service on the section via [[Prieska]] to [[Upington]] on the line to [[Windhoek]] in [[South West Africa]]. It remained in service there until 1958. Even though its service record and uniqueness justified preservation, it was scrapped in 1961.<ref name="Paxton-Bourne"/><ref name="Durrant"/>
==Illustration== The pictures illustrate the Class 20 locomotive as built with a Type MP1 tender, then fitted with a larger capacity Type MT2 tender, and finally after modification to an experimental condensing locomotive with a Type CL tender. <gallery mode=packed heights="220px"> File:SAR Class 20 2485 (2-10-2).JPG|No. 2485 with [[South African type MP1 tender|Type MP1 tender]], c. 1935 File:Class 20 no. 2485 (2-10-2).jpg|No. 2485 with [[South African type MT2 tender|Type MT2 tender]], c. 1945 </gallery> <gallery mode=packed heights="300px"> File:Class 20 no. 2485 (2-10-2) condenser.jpg|No. 2485 as experimental condensing locomotive with [[South African type CL tender|Type CL tender]], c. 1950 </gallery>
==References== {{Commons category|South African Class 20 (2-10-2)|South African Class 20 2-10-2}} {{Reflist}}
{{Locomotives of South Africa}} {{Steam locomotive tenders}}
[[Category:Steam locomotives of South Africa|2030]] [[Category:Individual locomotives of South Africa|2030]] [[Category:A.G. Watson locomotives|2030]] [[Category:2-10-2 locomotives]] [[Category:1′E1′ locomotives]] [[Category:SAR locomotives]] [[Category:Cape gauge railway locomotives]] [[Category:Railway locomotives introduced in 1935]] [[Category:1935 in South Africa]] [[Category:Experimental locomotives]] [[Category:Scrapped locomotives]]