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.
District Railway steam locomotives
District Railway steam locomotives were used on London's Metropolitan District Railway (commonly known as the District Railway). When in 1871 the railway needed its own locomotives, they ordered twenty four condensing steam locomotives from Beyer Peacock similar to the A Class locomotives the Metropolitan Railway was using on the route. As they were intended for an underground railway, the locomotives did not have cabs, but had a weatherboard with a bent-back top and the back plate of the bunker was raised to provide protection when running bunker first.