The Natal Government Railways Class K locomotives include three locomotive types, all designated Class K irrespective of differences in wheel arrangement.
When the Union of South Africa was established on 31 May 1910, the three Colonial government railways ( Cape Government Railways, Natal Government Railways and Central South African Railways) were united under a single administration to control and administer the railways, ports and harbours of the Union. Those Class K locomotives which still survived, were considered obsolete by the new South African Railways and renumbered with an "0" prefix to their existing engine numbers. [1]