Geared steam locomotive
This gearing is part of the machinery within the locomotive and should not be confused with the pinion that propels a rack locomotive along the rack between the rails. The geared steam locomotives that have been built have been for conventional track, relying on the adhesion between wheels and rail.
SR Leader class
Each of the two bogies had three cylinders, with the driving wheels connected by chains enclosed in an oil-bath, based upon Bulleid's chain-driven valve gear on his Pacific locomotives. The valve gear used the unusual sleeve valve arrangement that was also tested on the ex-LB&SCR H1 class "Hartland Point" in parallel with the construction of the first Leader locomotive. The Leader was the first steam locomotive to use a form of sleeve valve since Cecil Paget's locomotive of 1908 and the concurrent testing of the principle on "Hartland Point" hints at the rushed nature of the locomotive's conception. The locomotive sat on the unusual Bulleid Firth Brown wheels, which were lighter, yet stronger, than the spoked equivalent.