[3][4] How Garratts, to which Beyer, Peacock & Company held the patent, came to be designed and built by the German firm of Hanomag was the result of the coming into power of the Pact Government in South Africa in 1924.

Since the seats of the driver and stoker were mounted on poles which allowed them to be swung around to outside the cab, crews could often be seen riding outside to escape the heat.

Apart from appreciable economies in working, the Garratts enabled train loads and the carrying capacity of the narrow gauge lines to be virtually doubled without the need to strengthen track and bridges.

Some of these routes had curves of 45 metres (148 feet) radius and gradients of up to 3 in 100 (3%), but the Garratts were well suited to hauling the diverse freight traffic of pulpwood, sugar cane and bananas.

[7] The third order of seven locomotives, numbers NG77 to NG83, initially all went to the Avontuur Railway in the Langkloof where most of them remained for their entire service lives.

[7] The arrival of the Class NG G13s at Humewood Road in Port Elizabeth in 1928 came soon after the Avontuur Railway’s transition from a lightly-trafficked developmental line to a narrow-gauge heavy hauler when the new cement works at New Brighton were opened.

A limitation in the capacity of the limestone trains throughout the steam haulage era was that double heading by Garratt locomotives was not permitted to protect their pivots from excessive stresses.

From a passing loop at Summit, the Garratt would continue to Chelsea unassisted whilst the helper returned down the hill to Loerie.

[8] The Avontuur Garratts ended their service lives working out of Loerie, either hauling limestone trains to Van Stadens or doing duty on the Patensie branch line.

[1] Since withdrawal from SAR service, some locomotives were sold into private hands whilst others ended up in various degrees of preservation ranging across the spectrum from operational to plinthing to total abandonment.