What is "saddle roof"

Saddle \Sad"dle\, n. [OE. sadel, AS. sadol; akin to D. zadel, G. sattel, OHG. satal, satul, Icel. s["o][eth]ull, Dan. & Sw. sadel; cf. Russ. siedlo; all perh. ultimately from the root of E. sit.]

1. A seat for a rider, -- usually made of leather, padded to span comfortably a horse's back, furnished with stirrups for the rider's feet to rest in, and fastened in place with a girth; also, a seat for the rider on a bicycle or tricycle.

2. A padded part of a harness which is worn on a horse's back, being fastened in place with a girth. It serves various purposes, as to keep the breeching in place, carry guides for the reins, etc.

3. A piece of meat containing a part of the backbone of an animal with the ribs on each side; as, a saddle of mutton, of venison, etc.

4. (Naut.) A block of wood, usually fastened to some spar, and shaped to receive the end of another spar.

5. (Mach.) A part, as a flange, which is hollowed out to fit upon a convex surface and serve as a means of attachment or support.

6. (Zo["o]l.) The clitellus of an earthworm.

7. (Arch.) The threshold of a door, when a separate piece from the floor or landing; -- so called because it spans and covers the joint between two floors.

8. (Phys. Geog.) A ridge connected two higher elevations; a low point in the crest line of a ridge; a col.

9. (Mining) A formation of gold-bearing quartz occurring along the crest of an anticlinal fold, esp. in Australia.

   Saddle bar (Arch.), one the small iron bars to which the lead panels of a glazed window are secured.
   --Oxf. Gloss.

   Saddle gall (Far.), a sore or gall upon a horse's back, made by the saddle.

   Saddle girth, a band passing round the body of a horse to hold the saddle in its place.

   saddle horse, a horse suitable or trained for riding with a saddle.

   Saddle joint, in sheet-metal roofing, a joint formed by bending up the edge of a sheet and folding it downward over the turned-up edge of the next sheet.

   Saddle roof, (Arch.), a roof having two gables and one ridge; -- said of such a roof when used in places where a different form is more common; as, a tower surmounted by a saddle roof. Called also saddleback roof.

   Saddle shell (Zo["o]l.), any thin plicated bivalve shell of the genera Placuna and Anomia; -- so called from its shape. Called also saddle oyster.

n. saddleback

n. a double sloping roof with a ridge and gables at each end [syn: gable roof, saddleback, saddleback 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.

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.