Water Storage

Steam-powered vehicles need plenty of water to generate 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.

Water from the storage is supplied to the boiler by a device called the injector .

If the water storage runs dry it needs to be refilled .