A tender or coal-car is a special rail vehicle hauled by a steam locomotive containing its fuel (wood, coal, or oil) 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 a tender locomotive. Locomotives that do not have tenders and carry all their fuel and water on board the locomotive (itself) instead are called tank locomotives.