A saddle roof is a roof form which follows a convex curve about one axis and a concave curve about the other. The

hyperbolic paraboloid In geometry, a paraboloid is a quadric surface that has exactly one axis of symmetry and no center of symmetry. The term "paraboloid" is derived from parabola, which refers to a conic section that has a similar property of symmetry. Every plan ...

form has been used for roofs at various times since it is easily constructed from straight sections of lumber, steel, or other conventional materials. The term is used because the form resembles the shape of a

saddle The saddle is a supportive structure for a rider of an animal, fastened to an animal's back by a girth. The most common type is equestrian. However, specialized saddles have been created for oxen, camels and other animals. It is not kno ...

. Sometimes referred to as a hypar, the saddle roof may also be formed as a tensegrity structure. Mathematically, a saddle shape contains at least one

saddle point In mathematics, a saddle point or minimax point is a point on the surface of the graph of a function where the slopes (derivatives) in orthogonal directions are all zero (a critical point), but which is not a local extremum of the functi ...

. The historical meaning is a synonym for a

gable roof A gable roof is a roof consisting of two sections whose upper horizontal edges meet to form its ridge. The most common roof shape in cold or temperate climates, it is constructed of rafters, roof trusses or purlins. The pitch of a gable roof ...

particularly a ''dual-pitched'' roof on a tower, also called a ''pack-saddle roof''.Passmore, Augustine C.. "Saddle Roof". ''Handbook of technical terms used in architecture and building and their allied trades and subjects'',. London: Scott, Greenwood, and Co.;, 1904. 303. Print.

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Image:Church Army chapel 042.jpg, A hyperbolic paraboloid saddle roof:

Church Army Chapel, Blackheath The Church Army Chapel at Vanbrugh Park, Blackheath, Greater London, designed by project architect E.T. Spashett for Austin Vernon & Partners, opened in 1965 by Princess Alexandra and consecrated by Michael Ramsey, is a locally listed buildi ...

Image:Pengrowth_Saddledome.jpg, A hyperbolic paraboloid saddle roof: The

Scotiabank Saddledome Scotiabank Saddledome is a multi-use indoor arena in Calgary, Alberta, Canada. Located in Stampede Park in the southeast end of downtown Calgary, the Saddledome was built in 1983 to replace the Stampede Corral as the home of the Calgary Flame ...

in Calgary, 1983 Image:Dorton Arena West Side.JPG, Dorton Arena designed by Maciej Nowicki,

Raleigh Raleigh (; ) is the capital city of the state of North Carolina and the seat of Wake County in the United States. It is the second-most populous city in North Carolina, after Charlotte. Raleigh is the tenth-most populous city in the Southeas ...

North Carolina North Carolina () is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. The state is the List of U.S. states and territories by area, 28th largest and List of states and territories of the United ...

, United States, 1952 Image:London Velopark, 16 April 2012.jpg, A hyperbolic paraboloid saddle roof: the

London Velopark Lee Valley VeloPark is a cycling centre on Queen Elizabeth Olympic Park in Stratford, London, England. It is owned and managed by Lee Valley Regional Park Authority, and it was opened to the public in March 2014. The facility was one of the ...

Image:Gothia Towers, Mässan och Scandinavium 02.JPG, A hyperbolic paraboloid saddle roof: Scandinavium Image:W-wa Ochota PKP-WKD.jpg, A

roof of Warszawa Ochota railway station in

Warsaw Warsaw ( pl, Warszawa, ), officially the Capital City of Warsaw,, abbreviation: ''m.st. Warszawa'' is the capital and largest city of Poland. The metropolis stands on the River Vistula in east-central Poland, and its population is officiall ...

, Poland, 1962 Image:Wrexham Waterworld Leisure and Activity Centre.JPG, Wrexham Swimming Baths, now Wrexham Waterworld Leisure and Activity Centre, feature a hyperbolic paraboloid roof in

Wrexham Wrexham ( ; cy, Wrecsam; ) is a city and the administrative centre of Wrexham County Borough in Wales. It is located between the Welsh mountains and the lower Dee Valley, near the border with Cheshire in England. Historically in the count ...

Wales Wales ( cy, Cymru ) is a country that is part of the United Kingdom. It is bordered by England to the east, the Irish Sea to the north and west, the Celtic Sea to the south west and the Bristol Channel to the south. It had a population in ...

, United Kingdom, 1969 File:Canada Place - Vancouver 052.jpg, Multi-semi-hyperbolic-paraboloid roofs on Canada Place,

Vancouver Vancouver ( ) is a major city in western Canada, located in the Lower Mainland region of British Columbia. As the most populous city in the province, the 2021 Canadian census recorded 662,248 people in the city, up from 631,486 in 2016. ...

, Canada

References

External links

Kansas State Historical Society newsletter featuring house with hyperbolic paraboloid roof.

Architectural elements Roofs {{Architecturalelement-stub

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See also

References

External links