In 1880 and 1881, the Cape Government Railways placed eighteen 4th Class 4-6-0 tank-and-tender locomotives in mainline service on its Midland and Eastern Systems, working out of Port Elizabeth and East London respectively.

[1] Increasing traffic and heavier loads on the Cape Government Railways (CGR) lines into the interior from Port Elizabeth on the Midland System and East London on the Eastern System, led to a requirement for larger and more powerful locomotives by the late 1870s.

This was the first South African locomotive to be built to a local design, prepared in the CGR drawing office in Salt River.

[3][4] All the locomotives were delivered with optional three-axle tenders and, depending on the task at hand and the distance involved, could be used in either the tank engine or the tank-and-tender configuration.

One of the modifications introduced by Tilney was an extended smokebox to make room for a very efficient spark arrester, constructed of wire mesh.

[1][4] Another modification involved modifying the boiler and frame to accommodate oscillating firebars and a larger firebox to overcome the problems associated with the low-grade local coal from the Cyphergat collieries.

Mechanical firegrate shaking was accomplished by means of a collar on the leading coupled axle which could be engaged by a roller with eccentrically mounted connecting rods to the oscillating firebars.

They were considered obsolete by the SAR, designated Class 04 and renumbered by having the numeral "0" prefixed to their existing numbers.