structural engineering Structural engineering is a sub-discipline of civil engineering in which structural engineers are trained to design the 'bones and muscles' that create the form and shape of man-made structures. Structural engineers also must understand and cal ...

, a trestle support (or simply trestle) is a

structural element Structural elements are used in structural analysis to split a complex structure into simple elements. Within a structure, an element cannot be broken down (decomposed) into parts of different kinds (e.g., beam or column). Structural elements can ...

with rigid

beam Beam may refer to: Streams of particles or energy *Light beam, or beam of light, a directional projection of light energy **Laser beam *Particle beam, a stream of charged or neutral particles **Charged particle beam, a spatially localized grou ...

s forming the equal sides of two parallel

isosceles triangle In geometry, an isosceles triangle () is a triangle that has two sides of equal length. Sometimes it is specified as having ''exactly'' two sides of equal length, and sometimes as having ''at least'' two sides of equal length, the latter versio ...

s, joined at their

apices The apex is the highest point of something. The word may also refer to: Arts and media Fictional entities * Apex (comics), a teenaged super villainess in the Marvel Universe * Ape-X, a super-intelligent ape in the Squadron Supreme universe *Apex ...

by a

plank Plank may refer to: *Plank (wood), flat, elongated, and rectangular timber with parallel faces *Plank (exercise), an isometric exercise for the abdominal muscles * Martins Creek (Kentucky), the location of Plank post office * ''The Plank'' (1967 fi ...

or beam. Sometimes additional rungs are stretched between the two beams. A pair of trestle legs can support one or several boards or planks, forming a

trestle table In woodworking, a trestle table is a table consisting of two or three trestle supports, often linked by a stretcher (longitudinal cross-member), over which a board or tabletop is placed. In the Middle Ages, the trestle table was often litt ...

trestle desk There are two kinds of trestle desk: as with trestle tables, some have trestles joined by one or more stretchers (and sometimes to the desktop), and some have free-standing trestles. They can be dismantled, with the desk top removed from the tres ...

. A network of trestle supports can serve as the framework for a

trestle bridge A trestle bridge is a bridge composed of a number of short spans supported by closely spaced frames. A trestle (sometimes tressel) is a rigid frame used as a support, historically a tripod used to support a stool or a pair of isosceles trian ...

, and a trestle of appropriate size to hold wood for sawing is known as a

sawhorse In woodworking, a saw-horse or sawhorse (saw-buck, trestle, buck) is a trestle structure used to support a board or plank for sawing. A pair of sawhorses can support a plank, forming a scaffold. In certain circles, it is also known as a ''m ...

Trestle table

is a table with trestle legs. In shape and manufacture, it sometimes resembles variations of the antique field desk, which were used by officers close to the battlefield. Trestle legs come in two kinds: *Fixed trestle legs, where the angle between the legs is a fixed joint. *Folding trestle legs, where the angle is hinged, to make them more compact and portable. In the United States, a table or desk supported by X-shaped trestles is usually called a

sawbuck table A sawbuck table or X-frame table is a type of trestle table having X-shaped supports at either end. It takes its name from the similarity of these X-shaped supports to sawbucks. In addition to the supports, a sawbuck table is distinguished by a s ...

Trestle bridge

Dawson Creek railway trestle 2017 - 32055821593

A trestle bridge is composed of a number of short spans supported by closely spaced trestle frames. Each supporting frame is a bent. A trestle differs from a

viaduct A viaduct is a specific type of bridge that consists of a series of arches, piers or columns supporting a long elevated railway or road. Typically a viaduct connects two points of roughly equal elevation, allowing direct overpass across a wide v ...

in that viaducts have towers that support much longer spans and typically have a higher elevation. Timber and iron trestles (i.e. bridges) were extensively used in the 19th century, particularly for railroads. In the 21st century, steel and sometimes concrete trestles are occasionally used to bridge particularly deep valleys, while timber trestles remain common in certain areas. Timber trestles remain common in some applications, most notably for bridge approaches crossing floodways, where earth fill would dangerously obstruct floodwater. Many timber trestles were built in the 19th and early 20th centuries with the expectation that they would be temporary. Timber trestles were used to get the railroad to its destination. Once the railroad was running, it was used to transport the material to replace trestles with more permanent works, transporting and dumping fill around some trestles and transporting stone or steel to replace others with more permanent bridges.Charles Lee Crandall and Fred Asa Barnes
Railroad Construction
McGraw-Hill, New York, 1913; Section 96 – Wooden Trestles, pages 212–213.

References

{{Reflist *Gloag, John. A Complete Dictionary of Furniture. Woodstock, N.Y. : Overlook Press, 1991. *Moser,Thomas. Measured Shop Drawings for American Furniture. New York: Sterling Publishing Inc., 1985. Tables (furniture) Portable furniture

Trestle table

Trestle bridge

See also

References