South African Class GF 4 6 2 2 6 4

Manufacturers

During the term of office of Colonel F.R. Collins DSO as Chief Mechanical Engineer of the South African Railways (SAR) from 1922 to 1929, articulated locomotives were in great favour in South Africa, to the extent that the Railway Board of the day instructed that non-articulated engines should only be ordered in exceptional circumstances.

The specifications for the Class GF 4-6-2+2-6-4 Garratt locomotive were prepared by Colonel Collins and an order for 37 locomotives was placed with Hannoversche Maschinenbau AG (Hanomag) in Germany. They were delivered in December 1927 and numbered in the range from 2370 to 2406.

A second order for eighteen locomotives was placed with Henschel and Son in 1927. They were delivered in October 1928, numbered in the range from 2407 to 2424.

This was followed by a third order, placed with Maffei in 1928, for a final batch of ten locomotives. They were delivered in November of that same year and numbered in the range from 2425 to 2434.

Characteristics

The locomotives were superheated, had bar frames, piston valves and used Walschaerts valve gear. The Class GF was the only Double Pacific type Garratt to see service on the SAR and, until the arrival of the Class GMA, was the most numerous Garratt locomotive class in SAR service. It was designed as a mixed traffic locomotive for use on branchlines and secondary mainlines throughout the country.

As built, the Class GF had inside bearings in their two-wheeled trailing trucks and considerable trouble was experienced with hot-boxes on these axles. Once these were modified to outside bearings, they proved to be very successful locomotives. Their good turn of speed and reasonably high tractive effort made the class a good utility locomotive.

South African Railways

They saw service on many lines in Natal, Transvaal, the Orange Free State and the Eastern Cape. In Eastern Transvaal, they were stationed at Nelspruit to work the branches to Graskop and Plaston. Some worked out of Johannesburg via Krugersdorp and Zeerust on the Mafeking line as well. Here, they were allowed to carry an increased coal load of 11 long tons 10 hundredweight (11.7 tonnes), compared to the 10 long tons (10.2 tonnes) which they were allowed on lighter rail elsewhere.

The bulk of the Class GF fleet worked in Natal, some stationed at Empangeni to work the sugar cane traffic from Mtubatuba, while most were based at Mason's Mill to work the various branches which radiated from Pietermaritzburg. They worked a daily passenger train from Franklin to Kokstad, but on the other branches they were mainly used on goods and mixed train service.

Apart from four which were sold and two which were scrapped after collisions, they were all still in stock by 1972, although not all were still in operation. The last one in SAR service was scrapped in 1979.

Mozambique

Four of the Class GF, numbers 2370, 2419, 2420 and 2432, were sold to the Caminhos de Ferro de Moçambique, where they were designated the Series 911, numbered in the range from 911 to 914.

Industrial

Several of the Class GF locomotives were sold into mining service upon retirement. Most went to the Enyati Railway where, in later years, some were equipped with diesel-driven air brake equipment, installed in a cage behind the coal bunker, since some of the SAR's air braked coal export block trains originated on the Enyati. As far as is known, the locomotives in industrial service were the following:

Knuckle couplers

In 1927, the SAR began to convert the couplers of its Cape Gauge rolling stock from the Johnston link-and-pin coupling system, which had been in use since the establishment of the Cape Government Railways in 1873, to AAR knuckle couplers. Judging from the official SAR Locomotive Diagram Book and the dimensional drawings as published by Holland, both of which were for the most part based on the original as-delivered and unmodified loco­motives, as well as from contemporary photographs, the Class GF were acquired new with knuckle couplers fitted, as were the Classes 18, GCA, HF and U which also entered service in 1927.

Conversion of all rolling stock was to take several years and both coupler types could still be seen on rolling stock into the late 1950s. During the transition period, knuckle couplers on locomotives had a horizontal gap and a vertical hole in the knuckle itself to accommodate, respectively, a link and a pin, to enable it to couple to vehicles which were still equipped with the older Johnston couplers.

Preservation

Of the Class GF Garratts, eight survived into preservation, but numbers 2378, 2386, 2404 and 2425 were scrapped due to neglect and vandalism while preserved. By 2016, only no. 2380 at Inchanga was operational, no. 2401 was on display at the Outeniqua Transport Museum in George, no. 2387 was on static display in Paulpietersburg and no. 2416 was being restored by the Patons Country Railway.