Saddle roof

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 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 hyperbolic paraboloid is a doubly ruled surface, and thus can be used to construct a saddle roof from straight beams.A hyperbolic paraboloid saddle roof: Church Army Chapel, Blackheath.A hyperbolic paraboloid saddle roof: The Scotiabank Saddledome in Calgary, 1983.A hyperbolic paraboloid saddle roof: The Scotiabank Saddledome in Calgary, 1983.A hyperbolic paraboloid saddle roof: the London Velopark.A hyperbolic paraboloid saddle roof: Scandinavium.Dorton Arena designed by Maciej Nowicki, Raleigh, North Carolina, United States, 1952.A hyperbolic paraboloid roof of Warszawa Ochota railway station in Warsaw, Poland, 1962.Wrexham Swimming Baths, now Wrexham Waterworld Leisure and Activity Centre, feature a hyperbolic paraboloid roof in Wrexham, Wales, United Kingdom, 1969.Multi-semi-hyperbolic-paraboloid roofs on Canada Place, Vancouver, CanadaBMW Welt kurz vor der Fertigstellung, Milbertshofen-Am Hart, Germany.Pringles are examples of hyperbolic paraboloids. 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 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. 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. The historical meaning is a synonym for a gable roof particularly a dual-pitched roof on a tower, also called a pack-saddle roof.