s on apartment buildings on
East 57th Street in
New York City The adjacent image shows three architectural approaches to incorporating these tanks in the design of a building, one on East 57th Street in New York City. From left to right, a fully enclosed and ornately decorated brick structure, a simple unadorned roofless brick structure hiding most of the tank but revealing the top of the tank, and a simple utilitarian structure that makes no effort to hide the tanks or otherwise incorporate them into the design of the building. The technology dates to at least the 19th century, and for a long time New York City required that all buildings higher than six stories be equipped with a rooftop water tower. The original water tower builders were barrel makers who expanded their craft to meet a modern need as buildings in the city grew taller in height. Even today, no sealant is used to hold the water in. The wooden walls of the water tower are held together with steel cables or straps, but water leaks through the gaps when first filled. As the water saturates the wood, it swells, the gaps close and become impermeable. The rooftop water towers store of water until it is needed in the building below. The upper portion of water is skimmed off the top for everyday use while the water in the bottom of the tower is held in reserve to fight fire. When the water drops below a certain level, a pressure switch, level switch or float valve will activate a pump or open a public water line to refill the water tower. Historically, railroads that used
steam locomotives required a means of replenishing the locomotive's tenders. Water towers were common along the railroad. The tenders were usually replenished by
water cranes, which were fed by a water tower. Some water towers are also used as observation towers, and some restaurants, such as the
Goldbergturm in
Sindelfingen, Germany, or the second of the three
Kuwait Towers, in the State of
Kuwait. It is also common to use water towers as the location of
transmission mechanisms in the
UHF range with small power, for instance for closed rural broadcasting service,
amateur radio, or
cellular telephone service. In hilly regions, local topography can be substituted for structures to elevate the tanks. These tanks are often nothing more than concrete
cisterns terraced into the sides of local hills or mountains, but function identically to the traditional water tower. The tops of these tanks can be landscaped or used as park space, if desired.
Spheres and spheroids The
Chicago Bridge and Iron Company has built many of the water spheres and spheroids found in the United States. The website ''World's Tallest Water Sphere'' describes the distinction between a water sphere and water
spheroid thus: The
Union Watersphere is a water tower topped with a
sphere-shaped water tank in
Union, New Jersey, and characterized as the ''World's Tallest Water Sphere''. A
Star Ledger article suggested a water tower in
Erwin, North Carolina completed in early 2012, tall and holding , had become the World's Tallest Water Sphere. However, photographs of the Erwin water tower revealed the new tower to be a water spheroid. The water tower in
Braman, Oklahoma, built by the
Kaw Nation and completed in 2010, is tall and can hold . Slightly taller than the Union Watersphere, it is also a spheroid. Another tower in Oklahoma, built in 1986 and billed as the "largest water tower in the country", is tall, can hold , and is located in
Edmond. The
Earthoid, a perfectly spherical tank located in
Germantown, Maryland, U.S., is tall and holds of water. The name is taken from it being painted to resemble a globe of the world. The golf ball-shaped tank of the water tower at
Gonzales, California is supported by three tubular legs and reaches about high. The
Watertoren (or Water Towers) in
Eindhoven, Netherlands contain three spherical tanks, each in diameter and capable of holding of water, on three spires were completed in 1970. File:Wasserturm Ehrang.jpg|Disused sphere-shaped railway water tower in
Trier, Germany File:Pequot_Lakes_1.jpg|
Paul Bunyan's
Bobber Water Tower in
Pequot Lakes, Minnesota, U.S. File:East Bay Water Tower.jpg|
East Bay Township Water Tower near
Traverse City, Michigan, U.S. File:Waterbollen Eindhoven-02.jpg|
Eindhoven Water Towers, Netherlands File:Cocoa_water_tower_night.jpg|
Oblate spheroid water tower in
Cocoa, Florida, U.S. == Decoration and Traditions ==