Steam locomotives require a large amount of water, and water cranes are the equipment used for that purpose. So, why are they called water cranes? The main reason is that their shape resembles a curved pipe standing on the ground. A single curved pipe standing on the ground looks like a kind of bird “Crane”, hence the name “water crane.” However, water cranes do not use tap water. Water quality is crucial for steam locomotives. If there are dissolved substances in the water, they will form scales inside the boiler as the water evaporates, reducing the boiler system’s heat transfer efficiency. Therefore, clean and low-hardness mountain spring water must be used.