Water Storage

Steam vehicles need a lot of water to create steam, so they carry it onboard. Some locomotives are comprised of two units, with the first one carrying a large boiler and the second, called the tender, carrying a water tank reserve. Others have both the boiler and the tank on a single unit. The single unit locomotives are called tank locomotives, and are usually small and made for shunting or short travel distances.

See also: Boiler, Injector, Servicing