Duck Creek Aqueduct is a rare surviving example of a covered timber aqueduct. It was one of several similar structures on the Whitewater Canal, which operated between the Whitewater Valley and the Ohio River from 1839 to 1865. After being displaced by the railroad, the canal supplied hydraulic power for the industrial districts at Metamora and Brookville.
Bridges
Doe River Bridge is a fine example of a timber Howe truss, one of the most widely-used timber bridge designs. Built in 1884, this structure played an integral role in the development of the City of Elizabethton, Tennessee, and it is a rare example of a covered bridge that survives in an urban setting.
The original contract specified the unusual hip roof design, which resembles covered bridges in central Europe. The structure is very well-maintained and still carries automobile traffic. The bridge was restored in 2003.
Bunker Hill Bridge is the only surviving Haupt truss bridge in the U.S. and one of only two surviving covered bridges in North Carolina. Patented in 1839, the Haupt truss featured diagonal braces spanning multiple panels, which was an attempt to eliminate the cross-strain found in lattice truss bridges. Although it was almost immediately eclipsed by the Howe truss and never reached the mainstream of covered bridge building, the Haupt truss is of interest for its association with Gen.
The Ashuelot Covered Bridge is located at the center of Ashuelot, NH. It is a Town lattice truss bridge, spanning the Ashuelot River in a roughly north-south orientation. It consists of two spans with a total length of 178 feet (54 m). The total width of the bridge is 29 feet (8.8 m), and has a central roadway and sidewalks (measuring 3'10" in width) on each side. The bridge rests on stone abutments and a central pier. The abutments have been reinforced with concrete since the bridge was built, and the central pier has been protected by a metal breakwater.
Ackley Bridge is an excellent example of a multiple kingpost truss and a noteworthy early example of covered bridge preservation efforts in the United States. Built in 1832 by Joshua Ackley (b.1805) and Daniel Clouse (b.1812), Ackley Bridge originally spanned Enslow’s Branch of Wheeling Creek between Greene County and Washington County in Pennsylvania, where it carried traffic for over a century.
In the 1940s and 1950s, New Orleans experienced growth. Unfortunately, access from the north to the City continued to be limited by Lake Pontchartrain. Driving around the Lake was a time consuming effort. During this time period, a renewed interest developed to provide a direct connection across the center of the Lake to the north shore. As a result, the Greater New Orleans Expressway Commission was formed to build the Lake Pontchartrain Causeway Bridge. The original bridge (southbound) was opened on August 30, 1956.
Taken together, the 1940 and 1950 Tacoma Narrows bridges mark a significant turning point in the design of long-span suspension bridges. The original 1940 structure was designed with one of the shallowest and narrowest stiffening elements of any long-span suspension bridge yet built. The structure failed dramatically in a rather moderate 42 mph windstorm on 7 November 1940, only four months after opening for traffic.
In 1915, a tropical storm dropped nearly 11 inches of rain on St. Louis in just 17 hours, causing a devastating flood. Claiming 11 lives and the homes of 1,025 families, the flood focused public and government attention onto the problems of the river.
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Image Credit: Courtesy Wikipedia/MillbrookyImage Caption: Today, the River Des Peres Sewage & Drainage Works provides the backbone for the 110-square-mile St. Louis drainage basin.Era_date_from: 1924
1988
The Chamberlain is the only surviving bridge of the original five. The others were replaced as the river rose due to flood control dams put in place over time.
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Image Caption: Members of the South Dakota Army National Guard’s 200th Engineer Company guide a raft on the Missouri River during a river crossing operation on June 11, 2016. The Chamberlain in the background is the only surviving bridge of the five. The others were replaced as the river expanded due to flood control dams.Era_date_from: 1920
1994
The 1.5 mile Lacey V. Murrow Bridge was the largest floating structure in the world and the first to be built of reinforced concrete when completed in 1940. The bridge consisted of typically 300-foot long pontoons floated to site and rigidly connected to form a continuous structure and incorporated a unique floating concrete draw-span to allow for passage of marine traffic. The original floating structure, constructed by Pontoon Bridge Builders, was accidentally sunk in 1990 during a major renovation effort and was replaced by 1993.
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Image Credit: Courtesy Wikipedia/Walter SiegmundImage Caption: The bridge and tunnel project were key in improving eastern access to Seattle, a major commercial port on the eastern rim of the Pacific Ocean. Era_date_from: 1940
2008
Innovations
"An essential part of the human experience is to create an aesthetic atmosphere."
The George Washington Bridge represented a departure in suspension bridge design. Chief Engineer O.H. Ammann developed a system of stiffening trusses that offered greater flexibility and saved the project…
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Work began in 1887 on the high-level truss "Winner Bridge" crossing the Missouri River at Kansas City. The piers were completed in 1890, but for financial reasons the project was suspended. John Alexander Low Waddell, renowned civil engineer, prepared an alternate design for a lift bridge in…
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Hardy fishermen and their families have long inhabited Bailey Island, which was settled in the 1720s. Ordinarily, they did not mind crossing to the mainland in their fishing boats. But before the Bailey Island Bridge was built, during certain seasons of the year when violent storms battered the…
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The longest steel-arch bridge in the world for 46 years, the Bayonne Bridge continues to be celebrated today as a major aesthetic and technical achievement. The 1,675-foot bridge replaced a ferry service which until then was the only means of crossing from the Bayonne peninsula to Staten Island…
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Soon after gold was discovered at Sutter's Mill near Sacramento in 1848, General John Bidwell found gold near the Middle Fork of the Feather River. His discovery brought hordes of miners to the scene and Bidwell Bar was born. The Bidwell Bar Suspension Bridge over the Feather River was one of…
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Nicholas Montgomery Powers built the bridge. It was first constructed behind the village, then taken apart and reassembled over the stream. Some residents questioned the idea of re-constructing it, but Powers was so confident of the bridge's durability that he sat on the roof when the final…
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A product of the Northern California Gold Rush, the Bridgeport Covered Bridge is believed to be the longest, single-span, wooden covered bridge in the United States. Crossing the south fork of the Yuba River at a span of 233 feet, the bridge was built by the Virginia City Turnpike Company as…
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On May 24, 1883, with schools and businesses closed for the occasion, New York celebrated the opening of the Brooklyn Bridge. Also known as the Great East River Bridge, it was built over 14 years in the face of enormous difficulties. Deaths, fire in the Brooklyn caisson, and a scandal over…
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Cabin John Aqueduct, designed by Montgomery C. Meigs, conveys drinking water from Great Falls, Maryland to Washington, D.C. It was the longest stone masonry arch in the world for nearly 40 years. The segmental arch of the bridge has a span of 220 feet and a rise of only 57 feet. The main arch…
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For more than 174 years, the Canton Viaduct has stood as a dominating structure on the New England landscape. When completed in 1835, the slightly curved, granite masonry bridge - 615 feet long, 70 feet high, and 22 feet wide - carried a single track of the Boston and Providence Railroad,…
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In 1894, Catawba County, North Carolina commissioners asked local landowners to build and maintain an 85-foot-long bridge across Lyles Creek. The community hired Andy L. Ramsour, who served as keeper of the Horseford covered bridge over the Catawba River in Hickory, North Carolina.
…
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The Carrollton Viaduct over Gwynn's Falls was the first masonry railroad viaduct constructed in the United States. This structure proved the feasibility of using a viaduct to transport railway vehicles across wide and deep valleys.
The concept for the viaduct came from international…
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The Choate Bridge of Essex County, completed in 1764, is the oldest documented two-span masonry arch bridge in the United States. Named after Colonel John Choate, who supervised the construction, the bridge is located on South Main Street and spans the Ipswich River. Originally, the bridge…
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The total length of the Columbia-Wrightsville Bridge is 7,374 feet. Its construction required 100,000 cubic yards of concrete and 8 million pounds of steel reinforcing rods.
Consisting of 28 arches, each 185 feet long, the Columbia-Wrightsville Bridge carrying automobile traffic…
When a new road bridge was constructed alongside it, plans were made to demolish the Conwy Suspension Bridge. There was a national outcry and, since 1958, the bridge has been in the care of the National Trust and closed to vehicular traffic.
Designed by Thomas Telford in the gothic…
Built by Robert Stephenson to carry the Chester and Holyhead Railway across the River Conwy, this bridge was erected between 1846 and 1848. It consists of a single span 400 feet long, formed by two parallel rectangular wrought iron tubes, each weighing 1300 tons. Masonry towers were built on the…
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The Cornish-Windsor Covered Bridge is the longest wooden bridge in the United States and the longest two-span, covered bridge in the world. It is also a classic example of wooden bridge-building in 19th-century America. With copious supplies of timber at hand and a generous reserve of carpentry…
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In 1899, engineers from the City of Chicago's Division of Bridges and Viaducts performed a survey of moveable bridge design in the U.S. and Europe. Their study led to the conclusion that the unusual trunnion bascule design would best meet their needs.
The Cortland Street Drawbridge…
This elegant cast iron arch bridge designed by Scotland's famous Thomas Telford was built from 1812 to 1814. It is the earliest surviving example of a portable lattice-braced standard type that Telford developed for use at wide and deep water crossing sites unsuitable for masonry spans. …
The Delaware Aqueduct provided an important transportation link between the Pennsylvania's coalmines and New York's booming industrial marketplace. It is the earliest surviving work of John A. Roebling, who designed the Brooklyn Bridge 30 years later. The cable anchorage system first used…
