A water crane is a device used for delivering a large volume of water into the tank or tender of a steam locomotive. The device is sometimes also called a water column in the United States. As a steam locomotive consumes large quantities of water, water cranes were a vital part of railway station equipment, often situated at the end of a platform, so that water could be refilled during a stop at the station.
Generally, water cranes consist of an upright steel pipe about 8 to 12 inches (0.20 to 0.30 m) in diameter with a horizontal, pivoting pipe connected to its upper end so as to form a swinging arm. The swinging arm is usually designed to rest parallel to the rails when not in use. Water cranes may be able to deliver up to ten cubic metres (2,600 US gallons) of water per minute.
Water supply 
In hilly country, natural streams can be dammed and water fed by gravity to the water crane. In flatter country this arrangement is not always possible, so water may be supplied by a tank next to the crane. Water tanks may vary in volume from 190 kilolitres (50,000 US gal) to greater than 757 kilolitres (200,000 US gal). In some cases a well may be used to supply the water to the tank.
Depending on the quality of the water under supply, it may need to be treated chemically to eliminate hardness which induces scale buildup on the inside of the locomotive boiler. The scale builds up on heat transfer surfaces that insulate metal from the boiler water. This causes metal to overheat or corrode and eventually fail.
See also 
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- US patent 709376, John W. Thomas, Jr., "Stand-pipe for railway uses", issued 1902-09-16
- US patent 847494, James F. Murphy, "Railway stand-pipe", issued 1907-03-19
- US patent 958504, Patrick Henry Knight, "Stand-pipe for railway water-supply", issued 1910-05-17
- Railway and Locomotive Historical Society, Marietta, GA (2008). "The Railroad Station Water Column." Railway and Locomotive Historical Society Quarterly, Vol. 28, No. 4 - Vol. 29, No 1. p.6.
- Tratman, Edward Ernest Russell (1901). "Chapter 11. Water and Coaling Stations and Other Track Accessories". Railway Track and Track Work (2nd ed.). New York, New York: Engineering News Publishing Company. OCLC 2030207.
- Webb, Walter Loring (1917). Railroad Construction, Theory and Practice (6th ed.). New York, New York: John Wiley & Sons, Inc. pp. 376–377.
- Cleemann, Thomas M. (1880). The Railroad Engineer's Practice. New York, New York: George H. Frost, Publisher. pp. 71–73. OCLC 70728043.
- Guppy, B. W. (January–December 1919). "A Technical Description of the British Light Railways in France". Professional Memoirs of the Corps of Engineers, United States Army, and the Engineer Department at Large 11: 185–216.
- Wrinn, Jim (January 2012). "What's in the water?". Trains (Waukesha, Wisconsin: Kalmbach Publishing Company): 64. ISSN 0041-0934. OCLC 1642109.