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Covered Bridge
A covered bridge is a timber-truss bridge with a roof, decking, and siding, which in most covered bridges create an almost complete enclosure. The purpose of the covering is to protect the wooden structural members from the weather. Uncovered wooden bridges typically have a lifespan of only 20 years because of the effects of rain and sun, but a covered bridge could last over 100 years. In the United States, only about 1 in 10 survived the 20th century. The relatively small number of surviving bridges is due to deliberate replacement, neglect, and the high cost of restoration. European and North American truss bridges Typically, covered bridges are structures with longitudinal timber-trusses which form the bridge's backbone. Some were built as railway bridges, using very heavy timbers and doubled up lattice work. In Canada and the U.S., numerous timber covered bridges were built in the late 1700s to the late 1800s, reminiscent of earlier designs in Germany and Switzerland. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Truss Bridge
A truss bridge is a bridge whose load-bearing superstructure is composed of a truss, a structure of connected elements, usually forming triangular units. The connected elements (typically straight) may be stressed from tension, compression, or sometimes both in response to dynamic loads. The basic types of truss bridges shown in this article have simple designs which could be easily analyzed by 19th and early 20th-century engineers. A truss bridge is economical to construct because it uses materials efficiently. Design The nature of a truss allows the analysis of its structure using a few assumptions and the application of Newton's laws of motion according to the branch of physics known as statics. For purposes of analysis, trusses are assumed to be pin jointed where the straight components meet, meaning that taken alone, every joint on the structure is functionally considered to be a flexible joint as opposed to a rigid joint with strength to maintain its own shape, and th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Truss Bridge
A truss bridge is a bridge whose load-bearing superstructure is composed of a truss, a structure of connected elements, usually forming triangular units. The connected elements (typically straight) may be stressed from tension, compression, or sometimes both in response to dynamic loads. The basic types of truss bridges shown in this article have simple designs which could be easily analyzed by 19th and early 20th-century engineers. A truss bridge is economical to construct because it uses materials efficiently. Design The nature of a truss allows the analysis of its structure using a few assumptions and the application of Newton's laws of motion according to the branch of physics known as statics. For purposes of analysis, trusses are assumed to be pin jointed where the straight components meet, meaning that taken alone, every joint on the structure is functionally considered to be a flexible joint as opposed to a rigid joint with strength to maintain its own shape, and th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cogan House Covered Bridge
The Cogan House Covered Bridge is a Burr arch truss covered bridge over Larrys Creek in Cogan House Township, Lycoming County, in the U.S. state of Pennsylvania. It was built in 1877 and is long. The bridge was placed on the National Register of Historic Places in 1980, and had a major restoration in 1998. The Cogan House bridge is named for the township and village of Cogan House, and is also known by at least four other names: Buckhorn, Larrys Creek, Day's, and Plankenhorn. The Cogan House Covered Bridge was constructed by a millwright who assembled the timber framework in a field next to the sawmill, before it was reassembled at the bridge site. It was the only bridge on Larrys Creek that survived the flood of June 1889, and one of only a handful that were left intact in the county. Although the bridge used to carry a steady flow of tannery and sawmill traffic, the clearcutting of the surrounding forests meant the end of those industries by the early 20th century. Since then ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New York (state)
New York, officially the State of New York, is a state in the Northeastern United States. It is often called New York State to distinguish it from its largest city, New York City. With a total area of , New York is the 27th-largest U.S. state by area. With 20.2 million people, it is the fourth-most-populous state in the United States as of 2021, with approximately 44% living in New York City, including 25% of the state's population within Brooklyn and Queens, and another 15% on the remainder of Long Island, the most populous island in the United States. The state is bordered by New Jersey and Pennsylvania to the south, and Connecticut, Massachusetts, and Vermont to the east; it has a maritime border with Rhode Island, east of Long Island, as well as an international border with the Canadian provinces of Quebec to the north and Ontario to the northwest. New York City (NYC) is the most populous city in the United States, and around two-thirds of the state's popul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philadelphia
Philadelphia, often called Philly, is the largest city in the Commonwealth of Pennsylvania, the sixth-largest city in the U.S., the second-largest city in both the Northeast megalopolis and Mid-Atlantic regions after New York City. Since 1854, the city has been coextensive with Philadelphia County, the most populous county in Pennsylvania and the urban core of the Delaware Valley, the nation's seventh-largest and one of world's largest metropolitan regions, with 6.245 million residents . The city's population at the 2020 census was 1,603,797, and over 56 million people live within of Philadelphia. Philadelphia was founded in 1682 by William Penn, an English Quaker. The city served as capital of the Pennsylvania Colony during the British colonial era and went on to play a historic and vital role as the central meeting place for the nation's founding fathers whose plans and actions in Philadelphia ultimately inspired the American Revolution and the nation's inde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schuylkill River
The Schuylkill River ( , ) is a river running northwest to southeast in eastern Pennsylvania. The river was improved by navigations into the Schuylkill Canal, and several of its tributaries drain major parts of Pennsylvania's Coal Region. It flows for U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map , accessed April 1, 2011 from Pottsville to Philadelphia, where it joins the Delaware River as one of its largest tributaries. In 1682, William Penn chose the left bank of the confluence upon which he founded the planned city of Philadelphia on lands purchased from the native Delaware nation. It is a designated Pennsylvania Scenic River, and its whole length was once part of the Delaware people's southern territories. The river's watershed of about lies entirely within the state of Pennsylvania, the upper portions in the Ridge-and-valley Appalachian Mountains where the folding of the mountain ridges metamorphically modified bit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Market Street Bridge (Philadelphia)
The Market Street Bridge carries Market Street (Pennsylvania Route 3 eastbound), the primary east-west street in Philadelphia, Pennsylvania, across the Schuylkill River. The current bridge is the fifth permanent structure built at the site. Middle Ferry A ferry was established at or near this location by 1673. It came to be called the "Middle Ferry," because a ferry operated upstream ( Upper Ferry) and another downstream ( Lower Ferry). Early in the Revolutionary War, American General Israel Putnam built a pontoon bridge at the Middle Ferry site, made of floating logs bound together by rope. This was intentionally destroyed to prevent its falling into the hands of the British. The British Army built its own pontoon bridge at the site during the 1777-78 Occupation of Philadelphia. It washed away in 1780. Its replacement washed away in 1784. That was succeeded by a plank-floor bridge also built on floating logs. Market Street was originally known as "High Street," and this floati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schuylkill Permanent Bridge At High Street, The First Covered Bridge In America
Schuylkill may refer to: Places * Schuylkill, Philadelphia, neighborhood in South Philadelphia * Schuylkill County, Pennsylvania * Schuylkill Expressway, portion of I-76 in Philadelphia * Schuylkill Gap, water gap through Blue Mountain in Pennsylvania * Schuylkill Parkway, Pennsylvania Route 23 * Schuylkill River, a river in Pennsylvania * Schuylkill River Bridge on the Pennsylvania Turnpike * Schuylkill River Park, Philadelphia * Schuylkill River Trail * Schuylkill Township, Chester County, Pennsylvania * Schuylkill Township, Schuylkill County, Pennsylvania Other * Le Schuylkill, a high-rise residential building in Monaco * Schuylkill Branch, rail line in Pennsylvania * Schuylkill and Susquehanna Navigation Company, (1791-1811) navigation system connecting the rivers * Schuylkill Canal, (1815-1931) navigation system along the river from Port Carbon to Philadelphia, Pennsylvania * Schuylkill College, now Albright College, Reading, Pennsylvania * Schuylkill Institute of Business ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squire Whipple
Squire Whipple (September 16, 1804 – March 15, 1888) was an American civil engineer. Biography Squire Whipple was born in Hardwick, Massachusetts on September 16, 1804. His family moved to New York when he was thirteen. He received his secondary education at the Fairfield Academy Fairfield Academy was an academy that existed for nearly one hundred years in the Town of Fairfield, Herkimer County, New York. Founding It was organized as an academy for men in 1802, when the community was an active local manufacturing center. ... in Herkimer, New York, and graduated from Union College in New York after only one year. He has become known as the father of iron bridge building in America. - Whipple Cast & Wrought Iron Bowstring Truss Bridge, Normans Kill Vicinity, Albany, Albany County, NY (Biography on page 3) He died Mar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Howe Truss
A Howe truss is a truss bridge consisting of chords, verticals, and diagonals whose vertical members are in tension and whose diagonal members are in compression. The Howe truss was invented by William Howe in 1840, and was widely used as a bridge in the mid to late 1800s. Development The earliest bridges in North America were made of wood, which was abundant and cheaper than stone or masonry. Early wooden bridges were usually of the Towne lattice truss or Burr truss design. Some later bridges were McCallum trusses (a modification of the Burr truss). About 1840, iron rods were added to wooden bridges. The Pratt truss used wooden vertical members in compression with diagonal iron braces. The Howe truss used iron vertical posts with wooden diagonal braces. Both trusses used counter-bracing, which was becoming essential now that heavy railroad trains were using bridges. In 1830, Stephen Harriman Long received a patent for an all-wood parallel chord truss bridge. Long's bridge con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lattice Truss Bridge
A lattice bridge is a form of truss bridge that uses many small, closely spaced diagonal elements forming a lattice. The lattice Truss Bridge was patented in 1820 by architect Ithiel Town. Originally a design to allow a substantial bridge to be made from planks employing lower–skilled labor, rather than heavy timbers and more expensive carpenters, this type of bridge has also been constructed using many relatively light iron or steel members. The individual elements are more easily handled by the construction workers, but the bridge also requires substantial support during construction. A simple lattice truss will transform the applied loads into a thrust, as the bridge will tend to change length under load. This is resisted by pinning the lattice members to the top and bottom chords, which are more substantial than the lattice members, but which may also be fabricated from relatively small elements rather than large beams. Belfast truss The ''Belfast truss'' is a cross betw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Queen Post
A queen post is a tension member in a truss that can span longer openings than a king post truss. A king post uses one central supporting post, whereas the queen post truss uses two. Even though it is a tension member, rather than a compression member, they are commonly still called a post. A queen post is often confused with a queen strut, one of two compression members in roof framing which do not form a truss in the engineering sense. The double punch truss appeared in Central Europe during the Renaissance. Architecture A queen-post bridge has two uprights, placed about one-third of the way from each end of the truss. They are connected across the top by a beam and use a diagonal brace between the outer edges. The central square between the two verticals is either unbraced (on shorter spans), or has one or two diagonal braces for rigidity. A single diagonal reaches between opposite corners; two diagonal braces may either reach from the bottom of each upright post to the cente ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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