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Cornwall Railway Viaducts
The Cornwall Railway company constructed a railway line between Plymouth and Truro in the United Kingdom, opening in 1859, and extended it to Falmouth in 1863. The topography of Cornwall is such that the route, which is generally east–west, cuts across numerous deep river valleys that generally run north–south. At the time of construction of the line, money was in short supply due to the collapse in confidence following the railway mania, and the company sought ways of reducing expenditure. On the advice of the Victorian railway engineer Isambard Kingdom Brunel, they constructed the river crossings in the form of wooden viaducts, 42 in total, consisting of timber deck spans supported by fans of timber bracing built on masonry piers. This unusual method of construction substantially reduced the first cost of construction compared to an all-masonry structure, but at the cost of more expensive maintenance. Replacement of the timber viaducts by all-masonry structures began in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pinus Classification
''Pinus'', the pines, is a genus of approximately 111 extant tree and shrub species. The genus is currently split into two subgenera: subgenus ''Pinus'' (hard pines), and subgenus ''Strobus'' (soft pines). Each of the subgenera have been further divided into sections based on chloroplast DNA sequencing and whole plastid genomic analysis. Older classifications split the genus into three subgenera – subgenus ''Pinus'', subgenus ''Strobus'', and subgenus ''Ducampopinus'' ( pinyon, bristlecone and lacebark pines) – based on cone, seed and leaf characteristics. DNA phylogeny has shown that species formerly in subgenus ''Ducampopinus'' are members of subgenus ''Strobus'', so ''Ducampopinus'' is no longer used. The species of subgenus ''Ducampopinus'' were regarded as intermediate between the other two subgenera. In the modern classification, they are placed into subgenus ''Strobus'', yet they did not fit entirely well in either so they were classified in a third subgen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Truss
A truss is an assembly of ''members'' such as Beam (structure), beams, connected by ''nodes'', that creates a rigid structure. In engineering, a truss is a structure that "consists of two-force members only, where the members are organized so that the assemblage as a whole behaves as a single object". A ''two-force member'' is a structural component where force is applied to only two points. Although this rigorous definition allows the members to have any shape connected in any stable configuration, architectural trusses typically comprise five or more triangular units constructed with straight members whose ends are connected at joints referred to as ''Vertex (geometry), nodes''. In this typical context, external forces and reactions to those forces are considered to act only at the nodes and result in forces in the members that are either tension (physics), tensile or compression (physics), compressive. For straight members, moments (torques) are explicitly excluded because ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deep Foundation
A pile or piling is a vertical structural element of a deep foundation, driven or drilled deep into the ground at the building site. A deep foundation is a type of foundation (architecture), foundation that transfers building loads to the earth farther down from the surface than a shallow foundation does to a subsurface layer or a range of depths. There are many reasons that a geotechnical engineer would recommend a deep foundation over a shallow foundation, such as for a skyscraper. Some of the common reasons are very large design loads, a poor soil at shallow depth, or site constraints like property lines. There are different terms used to describe different types of deep foundations including the pile (which is analogous to a pole), the pier (which is analogous to a column), drilled shafts, and Caisson (engineering), caissons. Piles are generally driven into the ground ''in situ''; other deep foundations are typically put in place using excavation and drilling. The namin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trestle Support
In structural engineering, a trestle support (or simply trestle) is a structural element with rigid Beam (structure), beams forming the equal sides of two parallel isosceles triangles, joined at their Apex (geometry), apices by a Plank (wood), plank 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 or trestle desk. A network of trestle supports can serve as the framework for a trestle bridge, and a trestle of appropriate size to hold wood for sawing is known as a sawhorse. Trestle table A 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. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beam (structure)
A beam is a structural element that primarily resists loads applied laterally across the beam's axis (an element designed to carry a load pushing parallel to its axis would be a strut or column). Its mode of deflection is primarily by bending, as loads produce reaction forces at the beam's support points and internal bending moments, shear, stresses, strains, and deflections. Beams are characterized by their manner of support, profile (shape of cross-section), equilibrium conditions, length, and material. Beams are traditionally descriptions of building or civil engineering structural elements, where the beams are horizontal and carry vertical loads. However, any structure may contain beams, such as automobile frames, aircraft components, machine frames, and other mechanical or structural systems. Any structural element, in any orientation, that primarily resists loads applied laterally across the element's axis is a beam. Overview Historically a beam is a squared ti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strut
A strut is a structural component commonly found in engineering, aeronautics, architecture and anatomy. Struts generally work by resisting longitudinal compression, but they may also serve in tension. A stay is sometimes used as a synonym for strut, but some sources distinguish that struts are braces for holding compressive forces apart, while stays are braces for keeping stretching forces together. Human anatomy Part of the functionality of the clavicle is to serve as a strut between the scapula and sternum, resisting forces that would otherwise bring the upper limb close to the thorax. Keeping the upper limb away from the thorax is vital for its range of motion. Complete lack of clavicles may be seen in cleidocranial dysostosis, and the abnormal proximity of the shoulders to the median plane in cases of this genetic condition exemplifies the clavicle's importance as a strut. Architecture and construction Strut is a common name in timber framing for a support or brace of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pier (architecture)
A pier, in architecture, is an upright support for a structure or superstructure such as an arch or bridge. Sections of structural walls between openings (bays) can function as piers. External or free-standing walls may have piers at the ends or on corners. Description The simplest cross section (geometry), cross section of the pier is square (geometry), square, or rectangle, rectangular, but other shapes are also common. In medieval architecture, massive circle, circular supports called drum piers, cruciform (cross-shaped) piers, and compound piers are common architectural elements. Columns are a similar upright support, but stand on a round base; in many contexts columns may also be called piers. In buildings with a sequence of Bay (architecture), bays between piers, each opening (window or door) between two piers is considered a single bay. Bridge piers Single-span bridges have abutments at each end that support the weight of the bridge and serve as retaining walls to res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tie Rod
A tie rod or tie bar (also known as a hanger rod if vertical) is a slender structural unit used as a tie and (in most applications) capable of carrying tensile loads only. It is any rod or bar-shaped structural member designed to prevent the separation of two parts, as in a vehicle. Subtypes and examples of applications * In airplane structures, tie rods are sometimes used in the fuselage or wings. * Tie rods are often used in steel structures, such as bridges, industrial buildings, tanks, towers, and cranes. * Sometimes tie rods are retrofitted to bowing or subsiding masonry walls (brick, block, stone, etc.) to keep them from succumbing to lateral forces. The ends of the rods are secured by anchor plates which may be visible from the outside. * The rebar used in reinforced concrete is not referred to as a "tie rod", but it essentially performs some of the same tension-force-counteracting purposes that tie rods perform. * In automobiles, the ''tie rods'' are part of the steerin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wrought Iron
Wrought iron is an iron alloy with a very low carbon content (less than 0.05%) in contrast to that of cast iron (2.1% to 4.5%), or 0.25 for low carbon "mild" steel. Wrought iron is manufactured by heating and melting high carbon cast iron in an open charcoal or coke hearth or furnace in a process known as puddling. The high temperatures cause the excess carbon to oxidise, the iron being stirred or puddled during the process in order to achieve this. As the carbon content reduces, the melting point of the iron increases, ultimately to a level which is higher than can be achieved by the hearth, hence the wrought iron is never fully molten and many impurities remain. The primary advantage of wrought iron over cast iron is its malleability - where cast iron is too brittle to bend or shape without breaking, wrought iron is highly malleable, and much easier to bend. Wrought iron is a semi-fused mass of iron with fibrous slag inclusions (up to 2% by weight), which give it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cast Iron
Cast iron is a class of iron–carbon alloys with a carbon content of more than 2% and silicon content around 1–3%. Its usefulness derives from its relatively low melting temperature. The alloying elements determine the form in which its carbon appears: Cast iron#White cast iron, white cast iron has its carbon combined into an iron carbide named cementite, which is very hard, but brittle, as it allows cracks to pass straight through; Grey iron, grey cast iron has graphite flakes which deflect a passing crack and initiate countless new cracks as the material breaks, and Ductile iron, ductile cast iron has spherical graphite "nodules" which stop the crack from further progressing. Carbon (C), ranging from 1.8 to 4 wt%, and silicon (Si), 1–3 wt%, are the main alloying elements of cast iron. Iron alloys with lower carbon content are known as steel. Cast iron tends to be brittle, except for malleable iron, malleable cast irons. With its relatively low melting point, g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Burnett (physician)
Sir William Burnett, KCB, FRS (16 January 1779 – 16 February 1861) was a British physician who served as Physician-General of the Royal Navy. Early life Burnett was born in Montrose, Scotland on 16 January 1779 and attended Montrose Grammar School. He was appointed surgeon's mate on board the ''Edgar'' soon after his arrival at Edinburgh to pursue his medical studies. Later he served as assistant-surgeon in the ''Goliath'' under Sir John Jervis, and was present at St. Vincent and the siege of Cadiz. He also served with distinction at battles of the Nile and Trafalgar. Prison hospitals Between 1805 and 1810 Burnett was in charge of the hospitals for prisoners of war at Portsmouth and Forton. His diligence in his most arduous hospital duties recommended Burnett in 1810 for the office of Physician and Inspector of Hospitals to the Mediterranean Fleet. His health deteriorated and he returned to England towards the end of 1813; but in March 1814 he was able to undertake the me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
