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Thomas Viaduct
The Thomas Viaduct spans the Patapsco River and Patapsco Valley between Relay, Maryland and Elkridge, Maryland, USA. It was commissioned by the Baltimore and Ohio Railroad (B&O); built between July 4, 1833, and July 4, 1835; and named for Philip E. Thomas, the company's first president. It remains the world's oldest multiple arched stone railroad bridge. At its completion, the Thomas Viaduct was the largest railroad bridge in the United States and the country's first multi-span masonry railroad bridge to be built on a curve. In 1964, it was designated as a National Historic Landmark. In 2010, the bridge was designated as a National Historic Civil Engineering Landmark by the American Society of Civil Engineers. The viaduct is now owned and operated by CSX Transportation and still in use today, making it one of the oldest railroad bridges still in service. Design This Roman-arch stone bridge is divided into eight spans. It was designed by Benjamin Henry Latrobe, II, then B&O's a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patapsco River
The Patapsco River mainstem is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map , accessed April 1, 2011 river in central Maryland that flows into the Chesapeake Bay. The river's tidal portion forms the harbor for the city of Baltimore. With its South Branch, the Patapsco forms the northern border of Howard County, Maryland. The name "Patapsco" is derived from the Algonquian ''pota-psk-ut'', which translates to "backwater" or "tide covered with froth." History Captain John Smith was the first European to explore the river noting it on his 1612 map as the Bolus River. The "Red river", was named after the clay color, and is considered the "old Bolus", as other branches were also labeled Bolus on maps. As the river was not navigable beyond Elkridge, it was not a major path of commerce with only one ship listed as serving the northern branch, and four others operating around the mouth in 1723. The Patapsco River is referr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Span (architecture)
Span is the distance between two intermediate supports for a structure, e.g. a beam or a bridge. A span can be closed by a solid beam or by a rope. The first kind is used for bridges, the second one for power lines, overhead telecommunication lines, some type of antennas or for aerial tramways. The span is a significant factor in finding the strength and size of a beam as it determines the maximum bending moment and deflection. The maximum bending moment M_ and deflection \delta_in the pictured beam is found using: :M_ = \frac :\delta_ = \frac = \frac where :q = Uniformly distributed load :L = Length of the beam between two supports (span) :E = Modulus of elasticity :I = Area moment of inertia The second moment of area, or second area moment, or quadratic moment of area and also known as the area moment of inertia, is a geometrical property of an area which reflects how its points are distributed with regard to an arbitrary axis. The ... Note that the maximum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ellicott City, Maryland
Ellicott City is an unincorporated community and census-designated place in, and the county seat of, Howard County, Maryland, United States. Part of the Baltimore metropolitan area, its population was 65,834 at the 2010 census, making it the most populous unincorporated county seat in the country. Ellicott City's historic downtownthe Ellicott City Historic Districtlies in the valleys of the Tiber and Patapsco rivers. The historic district includes the Ellicott City Station, which is the oldest surviving train station in the United States, having been built in 1830 as the first terminus of the original B&O Railroad line. The historic district is often called "Historic Ellicott City" or "Old Ellicott City" to distinguish it from the surrounding suburbs that extend south to Columbia and west to West Friendship. History Milling In 1766, James Hood used the "Maryland Mill Act of 1669" to condemn for a mill site adjacent to his river-side property. His gristmill was built on t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Viaduct Wide Angle Shot
Thomas may refer to: People * List of people with given name Thomas * Thomas (name) * Thomas (surname) * Saint Thomas (other) * Thomas Aquinas (1225–1274) Italian Dominican friar, philosopher, and Doctor of the Church * Thomas the Apostle * Thomas (bishop of the East Angles) (fl. 640s–650s), medieval Bishop of the East Angles * Thomas (Archdeacon of Barnstaple) (fl. 1203), Archdeacon of Barnstaple * Thomas, Count of Perche (1195–1217), Count of Perche * Thomas (bishop of Finland) (1248), first known Bishop of Finland * Thomas, Earl of Mar (1330–1377), 14th-century Earl, Aberdeen, Scotland Geography Places in the United States * Thomas, Illinois * Thomas, Indiana * Thomas, Oklahoma * Thomas, Oregon * Thomas, South Dakota * Thomas, Virginia * Thomas, Washington * Thomas, West Virginia * Thomas County (other) * Thomas Township (other) Elsewhere * Thomas Glacier (Greenland) Thomas Glacier ( da, Thomas Gletscher) is a glacier in norther ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cast Iron
Cast iron is a class of iron– carbon alloys with a carbon content more than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its color when fractured: white cast iron has carbide impurities which allow cracks to pass straight through, grey cast iron has graphite flakes which deflect a passing crack and initiate countless new cracks as the material breaks, and 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 cast irons. With its relatively low melting point, good fluidity, castability, excellent machinability, resistance to deformation and wear resistance, cast irons have become an engineering material with a wide range of applications a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woodstock Quartz Monzonite
The Woodstock Quartz Monzonite is a Silurian or Ordovician quartz monzonite pluton in Baltimore County, Maryland. It is described as a massive biotite-quartz monzonite which intrudes through the Baltimore Gneiss at a single locality surrounding the town of Granite, Maryland. The extent of this intrusion was originally mapped in 1892 as the "Woodstock granite". It was given its current name in 1964 by C. A. Hopson.Hopson, C. A., 1964, The crystalline rocks of Howard and Montgomery Counties: Maryland Geological Survey County Report, 337 p., (Reprinted from Cloos, Ernst, and others, "Geology of Howard and Montgomery Counties," p. 27-215) Hopson grouped the Woodstock Quartz Monzonite with the Ellicott City Granodiorite and the Guilford Quartz Monzonite as "Late-kinematic intrusive masses." Woodstock granite has been used in the Capitol Building, the Library of Congress, and in buildings in Baltimore. Description The Woodstock Quartz Monzonite was described in 1898 as "perhaps ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quarry
A quarry is a type of open-pit mine in which dimension stone, rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some jurisdictions to reduce their environmental impact. The word ''quarry'' can also include the underground quarrying for stone, such as Bath stone. Types of rock Types of rock extracted from quarries include: *Chalk * China clay * Cinder *Clay *Coal *Construction aggregate (sand and gravel) *Coquina *Diabase *Gabbro *Granite *Gritstone *Gypsum *Limestone *Marble * Ores *Phosphate rock *Quartz *Sandstone *Slate *Travertine Stone quarry Stone quarry is an outdated term for mining construction rocks (limestone, marble, granite, sandstone, etc.). There are open types (called quarries, or open-pit mines) and closed types ( mines and caves). For thousands of years, only hand tools had been used in quarries. In the 18th century, the use of drilling and blasting operations w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ashlar
Ashlar () is finely dressed (cut, worked) stone, either an individual stone that has been worked until squared, or a structure built from such stones. Ashlar is the finest stone masonry unit, generally rectangular cuboid, mentioned by Vitruvius as opus isodomum, or less frequently trapezoidal. Precisely cut "on all faces adjacent to those of other stones", ashlar is capable of very thin joints between blocks, and the visible face of the stone may be quarry-faced or feature a variety of treatments: tooled, smoothly polished or rendered with another material for decorative effect. One such decorative treatment consists of small grooves achieved by the application of a metal comb. Generally used only on softer stone ashlar, this decoration is known as "mason's drag". Ashlar is in contrast to rubble masonry, which employs irregularly shaped stones, sometimes minimally worked or selected for similar size, or both. Ashlar is related but distinct from other stone masonry that i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Granite
Granite () is a coarse-grained ( phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies underground. It is common in the continental crust of Earth, where it is found in igneous intrusions. These range in size from dikes only a few centimeters across to batholiths exposed over hundreds of square kilometers. Granite is typical of a larger family of ''granitic rocks'', or '' granitoids'', that are composed mostly of coarse-grained quartz and feldspars in varying proportions. These rocks are classified by the relative percentages of quartz, alkali feldspar, and plagioclase (the QAPF classification), with true granite representing granitic rocks rich in quartz and alkali feldspar. Most granitic rocks also contain mica or amphibole minerals, though a few (known as leucogranites) contain almost no dark minerals. Granite is near ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maryland
Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to its east. Baltimore is the largest city in the state, and the capital is Annapolis. Among its occasional nicknames are '' Old Line State'', the ''Free State'', and the '' Chesapeake Bay State''. It is named after Henrietta Maria, the French-born queen of England, Scotland, and Ireland, who was known then in England as Mary. Before its coastline was explored by Europeans in the 16th century, Maryland was inhabited by several groups of Native Americans – mostly by Algonquian peoples and, to a lesser degree, Iroquoian and Siouan. As one of the original Thirteen Colonies of England, Maryland was founded by George Calvert, 1st Baron Baltimore, a Catholic convert"George Calvert and Cecilius Calvert, Barons Baltimore" William Hand Browne, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coping (architecture)
Coping (from ''cope'', Latin ''capa'') is the capping or covering of a wall. A splayed or wedge coping is one that slopes in a single direction; a saddle coping slopes to either side of a central high point. A coping may be made of stone (capstone), brick, clay or terracotta, concrete or cast stone, tile, slate, wood, thatch, or various metals, including aluminum, copper, stainless steel, steel, and zinc. In all cases it should be weathered (have a slanted or curved top surface) to throw off the water. In Romanesque work, copings appeared plain and flat, and projected over the wall with a throating to form a drip. In later work a steep slope was given to the weathering (mainly on the outer side), and began at the top with an astragal; in the Decorated Gothic style there were two or three sets off; and in the later Perpendicular Gothic these assumed a wavy section, and the coping mouldings continued round the sides, as well as at top and bottom, mitring at the angles, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spandrel Arch
An arch bridge is a bridge with abutments at each end shaped as a curved arch. Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side. A viaduct (a long bridge) may be made from a series of arches, although other more economical structures are typically used today. History Possibly the oldest existing arch bridge is the Mycenaean Arkadiko Bridge in Greece from about 1300 BC. The stone corbel arch bridge is still used by the local populace. The well-preserved Hellenistic Eleutherna Bridge has a triangular corbel arch. The 4th century BC Rhodes Footbridge rests on an early voussoir arch. Although true arches were already known by the Etruscans and ancient Greeks, the Romans were – as with the vault and the dome – the first to fully realize the potential of arches for bridge construction. A list of Roman bridges compiled by the engineer Colin O'Connor features 330 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
