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.
Tender (rail)
Certain early British steam locomotives were fitted with powered tenders. As well as holding coal and water, these had wheels powered from the locomotive to provide greater tractive effort. These were abandoned for economic reasons; railwaymen working on locomotives so equipped demanded extra pay as they were effectively running two locomotives. However, the concept was tried again on the Ravenglass and Eskdale Railway's "River Mite", and the Garratt locomotive may be seen as an extension of this principle. Powered tenders were also seen on the 2-8-8-8-2 and 2-8-8-8-4 locomotives in the United States, but these experiments were not considered successful. Powered tenders were used extensively on geared logging steam locomotives like the Shay locomotive, Climax locomotive, and Heisler locomotive where the steep grades and heavy trains necessitated the extra tractive effort.