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.
Swiss locomotive and railcar classification
Steam powered tank locomotives were always given an "E", and the maximum speed of the locomotive was designated with a lower case letter. Thus, an Ea 3/6 was a tank locomotive with v > , three coupled drive axles, and three unpowered axles. With steam locomotives, separate driving mechanisms were displayed. So, for example, a Mallet locomotive was named G 2x2/2 or G 2/3+2/2, and not G 4/4 or G 4/5.