South African Class GL 4-8-2+2-8-4
The South African Railways Class GL 4-8-2+2-8-4 of 1929 was an articulated steam locomotive. In 1929 and 1930, the South African Railways placed eight Class GL Garratt articulated steam locomotives with a 4-8-2+2-8-4 Double Mountain type wheel arrangement in service. Built by Beyer, Peacock & Company in Manchester, England, they were originally designed to work on the Durban to Cato Ridge section of the Natal mainline. The Class GL was eventually displaced to the route between Glencoe and Vryheid before spending their final working years operating on the line from Stanger to Empangeni. Origin The Class GL had its origin in the steady increase in loads experienced by the Natal mainline in the years prior to the First World War. The old Natal mainline had gradients of 1 in 30 (3⅓%) whilst the newer line, relocated to provide an easier route, still had of near-uninterrupted 1 in 66 (1½%) gradients. Moreover, the tight curvature of the line with curves of as little as radius precluded the use of large, long wheelbased, non-articulated locomotives and restricted them to a coupled wheelbase of . These factors combined with ever-increasing train weights ensured that the line rapidly became a bottleneck. The decision to