Overview SAR Rail Gauges Wheel Arrangement Classification Locomotive Frames Heat and Combustion

Technical - SAR Rail Gauges

The first gauge used in South Africa in 1859 was the 4' 8½" (Fig. 1). This was used on the privately owned Cape and Natal Railways long before the SAR, and conformed to the British standard. Apart from being very costly to lay, this was a very impractical gauge for the South African terrain, due to the sharp curves required to negotiate the landscape.
 
Another privately owned railway was also built to carry copper from inland to the coast in the north-western Cape. This line had a gauge of 2' 6" (Fig. 2), and was in existence at the same time as the Cape and Natal gauge of 4' 8½". Although this was a lot more suited to the landscape, problems arose when locomotives from each gauge could not be used on all lines. In 1873 a decision was made by the Cape Parliament to standardise on a single gauge, and a compromise was made between the 4' 8½" and 2' 6" gauges. It was then that the 3' 6" Cape gauge was born.
 
 

Although classed as Narrow Gauge when compared to world standards, the 3' 6" gauge (Fig. 3) has proved to be the more popular gauge suited to the South African environment. It is the only official gauge in use by Transnet today. It has a loading gauge of 13' 0" (Fig. 3), and is available in various weights for main and branch lines.

 
There were areas, particularly in the Cape and Natal, that were too rugged for the standard 3' 6" gauge to handle the sharp curves of the terrain. The Cape and Natal are well known for their mountainous and very hilly landscapes. It was for this reason that 2' 0" gauge lines (Fig.4) were constructed primarily in the Cape and Natal provinces. These lines were classed as Narrow Gauge (NG) in South Africa. Although these lines were a lot cheaper to construct, problems arose again, when having to join with the wider Cape gauge lines. There are only a few Narrow Gauge lines left in South Africa, and are being maintained by preservation societies.