Rhodesia Railways 4-8-2 Locomotives in Rhodesia

Class 10th class (Locobase 20117)

Data from "Narrow Gauge Locomotive for the Rhodesian Railway", The Engineer, Volume CXV [115], No 14 (7 March 1913), p. 248. See also A E Durrant, "The Smoke that Thunders" (Harare, Zimbabwe:African Publishing Company, 1997), pp. 67-71. Works numbers were 19996-20002 in 1913, 22796-22801 in 1922, 23089 in 1924, and 23972-23977 in 1930.

Designed by locomotive superintendent W J Hosgood of the Rhodesian and Mashonaland Railways, this designed owed much to the South African Railways' 4A class. But the lighter construction in Rhodesia (e.g. rail weight was 60 lb/year--30 kg/metre) led to some key differences including a narrower boiler, a somewhat smaller grate, and less cylinder volume. Piston valves measured 8" (203 mm) in diameter.

Durrant says that the SAR's Class 4 and Class 4As were "odd ones out ...By comparison, the smaller RR 10th class was a total success, the largest engines on the system when built." One wonders if the outsized superheater might have helped.

During most of their careers, the 10s were based at Mafeking, where crews from South Africa hauled most of the traffic through Bechuanaland.

153 and 241 collided head on on 4 April 1938 and were scrapped. All of the 1913 and 1922 locomotives were scrapped by the end of 1961. Two survivors were put on display: class leader 98 can still be seen at Bulawayo and 156 went to the Livingstone Museum.

The surviving six 1930 locomotives were all scrapped in April 1972.

Class 11th class (Locobase 20791)

Data from "4-8-2 Locomotive, Rhodesian Rys", Locomotive Magazine, Volume XXVI [26] (15 March 1920), p. 47. See also A E Durrant, "The Smoke that Thunders" (Harare, Zimbabwe:African Publishing Company, 1997), pp. 67-71. Works numbers were 59115-59123, 59940-59948 in September 1918, and 62273-62284 in 1923.

These North American-built Mountains followed the South African Class 3 design of 1912 (Locobase 2940) fairly closely, but reorganized the boiler tube layout slightly, fitted a copper Belpaire firebox, and increased driver diameter. Piston valve diameter measured 11" (279 mm).

To LM, the weight was a "great load", but the engine offered easy running, "further ensured by ...a very complete system of spring compensation in accordance with modern American design." Bogie and trailing truck flexibility was "enhanced by the broad flangeless tyres of the leading coupled wheels."

Although its heating surface area grew both in tubes and superheater areas, the engines came in quite a bit lighter than the SAR inspiration. The lighter weight may have been due to differences in frame thickness, wrote Dusty Durrant, "as certainly the RR [Rhodesian Railways] locos had trouble later with frame cracking. Another deficiency apparently caused by too light a locomotive for the power provided was "a reputation for slipping under less than ideal track conditions."

The RR later reduced cylinder diameter slightly, but could not shorten cylinder stroke.

It was, LM said, "well suited for operating heavy traffic on narrow gauge roads."

Most of the class operated in northern Rhodesia, the class eventually congregating at Livingstone initially and moving up to the copperbelt still farthern north in the early 1930s. In the two decades between 1940 and 1960, 11th class locomotives were based primarily at Ndola and Nkana as well as at Broken Hill.

Most of the class was retired in the early 1960s and were eventually scrapped. 144-145 and 149-152 were sold to the state railway CFM in Mozambique as their 441-445. 127 was presevered inoperable in a museum.