High Quality Content by WIKIPEDIA articles! In 1909 the Natal Government Railways placed its first true Mountain type locomotive in service when five Class Hendrie D 4-8-2 tender locomotives were commissioned. Twenty-five more were placed in service in 1911. In 1912, when they were assimilated into the South African Railways, they were renumbered and classified as Class 3. The Mountain wheel arrangement went on to become the most numerous steam locomotive wheel configuration in use in South Africa.