The South African Railways Class 23 4-8-2 was a class of South African steam locomotives. In 1938 and 1939, the South African Railways placed 136 Class 23 steam locomotives in service. The Class 23 was the last and the largest 4-8-2 Mountain type locomotive to be designed by the South African Railways. Manufacturers The Class 23 4-8-2 Mountain type steam locomotive was designed by W.A.J. Day, Chief Mechanical Engineer (CME) of the South African Railways (SAR) from 1936 to 1939. It was intended as a general utility locomotive, capable of operating on rail, and was built in two batches by Berliner Maschinenbau and Henschel and Son in Germany. The original order in 1938 was for twenty locomotives, of which Berliner built seven, numbered in the range from 2552 to 2558, and Henschel thirteen, numbered in the range from 2559 to 2571. At the time, the urgency brought about by the rapidly deteriorating political climate in Europe led to a further 116 locomotives being ordered even before the first batch could be delivered and tested, contrary to usual SAR practice. Ordering this quantity of a new class of engine before any had been tried out constituted a record for the SAR. Of this second batch, Henschel built 85, numbered in the range from 3201 to 3285, and Berliner 31, numbered in the range from 3286 to 3316. The last locomotive of this second order was delivered in August 1939, just one month before the outbreak of the Second World War. Berliner-built locomotive no. 3301 received an out-of-sequence works number, Berliner no. 10816 instead of no. 11000, since works number 11000 was reserved for the new Class 01.10 4-6-2 Pacific type locomotive for the German State Railways. Characteristics In general appearance and power, the Class 23 locomotive is very similar to the Classes 15E and 15F. As originally designed, the locomotive would have had coupled wheels which would have required a newly designed boiler to accommodate the extra length brought about by the long coupled wheelbase. The increasing political turmoil in Europe and the resulting urgency, however, prohibited time being spent on designing a new boiler. As a result, the existing Watson Standard no. 3B boiler was incorporated in the design with an extra long smokebox which was extended by to partially compensate for the shorter boiler. This boiler was one of the range of standard type boilers which was designed by