The 16th class was a “Double Mikado” Garratt procured by the Rhodesia Railways from 1929 as a more powerful addition to the 13th and 14th class “Double Prairie” Garratts. It had many features in common with its predecessors, but added a considerable amount of adhesive weight with two additional driving axles and had larger cylinders. The rigid wheelbase of 8 ft 9 in given in the Beyer-Peacock catalogue indicates that one driving axle in each group must have had lateral play.
Three batches of eight, six and six locomotives each were built in 1929, 1937 and 1938. Operating in the area around the Victoria Falls Bridge, they hauled more than 700 tons over two percent inclines with curve radii of 462 feet. They were often seen working in tandem or with the second locomotive placed in the middle of the train, what was called “dupla”.
In 1953, 30 locomotives of a modernized variant were built as class 16A. These featured an increased boiler pressure, larger supplies and roller bearings on the bogie axles. The boiler had been modified and now had similar dimensions to that of the class 15A. These locomotives could be distinguished from the earlier ones by the rounded or streamlined bunkers.
The original 16th class was withdrawn relatively early. In 1964, nine were sold to Angola and rebuilt to eucalyptus firing. Others came to collieries, some also in South Africa. The class 16A remained in service for a longer time and later came to Zambia Railways and National Railways of Zimbabwe. In 1979 and 1980, the locomotives were refurbished with roller bearings on all axles, what allowed them to haul passenger trains at speeds well over 50 mph or 80 km/h. Some of them were only withdrawn in the nineties.