Four tank-and-tender locomotives of the CGR's Experimental 4th Class were supplied by Neilson in 1884, built to the design of J.D. Tilney, Locomotive Superintendent of the Cape Eastern System at the time, to be able to use low-grade local coal. They had Joy valve gear and unusual six-wheeled tenders, with the leading axle mounted in a rigid frame and the other two axles mounted in a bogie. One of the locomotives survived until 1912 and was designated SAR Class 04 as an obsolete locomotive.