The South African Railways Class 18 2-10-2 of 1927 was a steam locomotive. In December 1927 and January 1928 the South African Railways placed two Class 18 three-cylinder steam locomotives with a 2-10-2 Santa Fe type wheel arrangement in service on the Witbank-Germiston coal line. Manufacturer The Class 18 2-10-2 Santa Fe type steam locomotive was designed by Colonel F.R. Collins DSO, Chief Mechanical Engineer (CME) of the South African Railways (SAR) from 1922 to 1929, and built by Henschel and Son in Germany. Two locomotives were delivered in 1927 and 1928, numbered 1360 and 1361. Characteristics They were very powerful three-cylinder locomotives. At the time, three-cylindered locomotives were being built in appreciable numbers in Europe and America. Factors in their favour were their more even turning moment, improved balancing and better distribution of crank-pin thrust. Drawbacks were increased complexity and higher repair cost. When delivered, the third cylinder was clearly visible, but plating was subsequently added beneath the smokebox and hid it from view. These were the most powerful non-articulated steam locomotives to see service on the SAR, with a tractive effort of at 75% boiler pressure and capable of hauling loads of over the ruling gradient of 1 in 100 (1%) on the Witbank-Apex section. Contemporary Henschel publicity appropriately referred to them as the "Henschel Giants". They were larger in most respects than Deutsche Reichsbahn's new Standard gauge Class 44 three-cylinder 2-10-0 locomotives. Although their all-up locomotive weight was almost the same, when considering the fact that the SAR's Cape gauge Class 18 had shorter axles and frame stretchers, saving weight that could then be built into other items such as the firebox, the Class 18 was the larger locomotive. The Class 18 had a round-topped firebox with a combustion chamber and with arch tubes supporting the brick arch. It was fired by a Duplex D.4 type mechanical stoker, operated by a four-cylinder steam engine on its Type HT tender, which had a coal capacity of , a water capacity of and a maximum axle load of . To allow the locomotive to negotiate curves of radius despite its long coupled wheelbase, the third and fourth pairs of driving wheels were flangeless. In addition, the locomotive made use of a Krauss-Helmholtz bogie system, where the leading pair of driving wheels has a limited amount of sideplay with an articulated link to the leading bissel bogie. The bissel bogie