spindles and secured with locknuts. Although this made adjustment easier, it was not satisfactory in service and was later replaced by the usual taper fit with cotter pin. With these two exceptions, the mechanical parts of the Class 19 gave very little trouble. As built, the Class 19 was delivered with Type MS tenders with an coal and a water capacity and an axle load of . Successors Following the pilot project with only four Class 19 locomotives, four variants on the class were acquired over the next twenty-one years. The slightly smaller Class 19A in 1929. The Class 19B in 1930. The Class 19C in 1935. The Class 19D between 1936 and 1949. The Class 19 family earned a reputation for reliability, easy handling, long periods between overhauls and economical operation. While preparing the specifications, Loubser gave considerable thought to the layout of this locomotive and the Research and Test Department was consulted on the most suitable wheel arrangement and other design details. The end result more than justified the amount of care and thought taken during the design process. Watson Standard boilers From the 1930s, many serving locomotives were reboilered with a standard boiler type designed by then CME A.G. Watson as part of his standardisation policy. Such Watson Standard reboilered locomotives were reclassified by adding an "R" suffix to their classification. In 1966, when Class 19 no. 1367 was reboilered with a Watson Standard no. 1A boiler, it became the sole Class 19R. The Watson Standard no. 1A boiler was designed to the same basic dimensions as the Class 19 boiler, but with more superheater elements, a different tube arrangement and larger diameter small tubes. In the process of reboilering, no. 1367 was also equipped with a Watson cab with its distinctive inclined front compared to the conventional vertical front of the original cab. While an obvious visual difference between an original and a Watson Standard reboilered locomotive is usually a rectangular regulator cover just to the rear of the chimney on the reboilered locomotive, the slanted front of the new cab on no. 1367 served as an even more obvious identifying feature. Service The four Class 19 locomotives were placed in service on the line between Kimberley and Vryburg, but they eventually spent their later working years at Empangeni and on the Bergville branch in Natal. In the 1950s, they were used especially on passenger trains