tender

Sierra Railway No. 3 tender A British SE&CR O1 class runs tender-first at the Bluebell Railway Cutaway cross section showing a Spanish tender designed for fuel oil. Green areas hold water and brown areas hold fuel oil. There is a special arrangement to prevent sloshing around during the movement of the train.

A tender is a special rail vehicle hauled by a steam locomotive containing its fuel (wood, coal, oil or torrefied biomass) and water. Steam locomotives consume large quantities of water compared to the quantity of fuel, so their tenders are necessary to keep them running over long distances. A locomotive that pulls a tender is called either a tender locomotive or a tender engine. Locomotives that do not have tenders and carry all their fuel and water on board are called tank locomotives.