"It remains today one of the great bridge engineering accomplishments for railway and highway bridges built in the country."
- Historic American Engineering Record, Southeast Regional Office, National Park Service, U.S. Department of the Interior, 2005
Bridge
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.
Conceived as one of the major structures on the Prussian Eastern Railway, the Old Wisla Bridge at Tczew originally consisted of six wrought iron spans. Due to Germany's invasion of Poland at the beginning World War II in 1939, only three original spans remain today. These remaining spans represent a unique technical monument of civil engineering achievements in the mid-nineteenth century.
When this 1,850-foot concrete-arch highway bridge was built on the White River in a remote region of northern Arkansas - prior to the construction of upriver, flood-control dams - flash floods occurred frequently, sometimes causing the water to rise as much as one foot per hour. Construction under these conditions presented a clear danger, so project managers specified both a design and an innovative construction method appropriate to the problem of building across a perilous stretch of unpredictable river.
The Whipple Bowstring Truss Bridge was built from a design patented in 1841 by Squire Whipple. Whipple was the first person to understand the stresses in truss members and he developed the first theoretical formula to calculate stresses in the articulated truss. His bowstring truss was the first to use cast iron for compression and wrought iron for tension membranes.
The structure has two segments: an East Channel bridge consisting of four 175-foot spans and three 240-foot spans crossing from Harrisburg to City Island; and a West Channel bridge, consisting of seven 175-foot spans crossing from City Island to Wormleysburg.
With 15 truss spans totaling 2,820 feet, the Walnut Street Bridge is the finest and largest surviving example of the standardized Phoenix wrought-iron truss bridges produced from 1884 to 1923.
Designed by David B. Steinman, of Robinson & Steinman, New York City, the Waldo-Hancock suspension Bridge is a significant example of Steinman's work. David Steinman is considered among the most important suspension bridge designers of the 20th century. He earned an engineering degree from Columbia University in 1909 and went on to apprentice with Gustav Lindenthal, then at work on New York's Hell Gate Bridge. In the 1920's, Steinman emerged as an outstanding and innovative suspension bridge designer.
This majestic viaduct was built during the golden age of railroading. It was at the western end of a major readjustment in grade and alignment of the Erie-Lackawanna Railroad, and had double tracks to carry the trains across the valley of Tunkhannock Creek. The Hallstead cutoff (between Scranton, Pennsylvania and Hallstead, New Jersey) reduced passenger travel time by 20 minutes, and freight travel time by over an hour.
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…
Read MoreCabin 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…
Read MoreThe 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…
Read MoreWhen 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…
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…
Read MoreThe 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…
Read MoreIn 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…
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…
Not only was Dunlap's Creek Bridge the first cast-iron bridge in America, it was the first metal bridge anywhere to use what its builder, Capt. Richard Delafield, U.S. Army Corps of Engineers, described as "standardized, interchangeable, manufactured parts." The bridge was built as part…
In the decade following the Civil War, the Mississippi River began to lose its standing as the primary transport artery in the Midwest. Railroads were taking over, and Chicago was rapidly becoming the center of Midwestern commerce. The Eads Bridge was the first major railroad link over…
The Wheeling Suspension Bridge was the first bridge to span the Ohio River. It was initially completed in 1849, but destroyed by a tornado five years later. The bridge was rebuilt in 1856. The replacement bridge has the same general appearance of the original structure; the massive towers,…
Read More"For 273 years, the little stone bridge that carries Frankford Ave. across Pennypack Creek has been doing its humble job with a minimum of attention..."
- Gerald McKelvey, The Philadelphia Inquirer, September 16, 1970
Built more than a century before the reign of Napoleon,…
Read MoreWhen opened in 1909, the 1,470 foot long main span of the Manhattan Bridge was the third longest suspension bridge span in the world, after the nearby Brooklyn and Williamsburg Bridges. The Manhattan Bridge has two 725 foot long suspended side spans for an overall length of 2,920 feet. The…
Read MoreThe Memphis Bridge (now called the Frisco Bridge) comprises three spans across the Mississippi River. With a main span measuring over 790 feet, it was one of the longest railroad bridges in the world upon completion. The renowned George Morison, after whom the bridge is unofficially named,…
Read MoreDesigned, patented, and built by Thomas W.H. Moseley, this arched 96-foot span bridge preceded by years the standard use of wrought iron for bridges. For the first time in the United States, Moseley incorporated the use of riveted wrought-iron plates for the triangular-shaped top chord.
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Read MoreNavajo Bridge spans Marble Canyon, 470 feet above the Colorado River in Grand Canyon National Park. It was considered the highest steel arch bridge in America when completed.
The Navajo Bridge (also known as the Grand Canyon Bridge) was built in 1929 by the Arizona Highway Department and…
Read MoreThe crossing of the Delaware River at Easton, Pennsylvania, provided a central link in travel from the northeastern seaboard to America's inland territories throughout the 18th and early 19th centuries. From 1806 to the mid-1890s, travelers used a landmark wooden structure built by noted bridge-…
Read MoreBuilt to cross one of the steepest valleys along the Douro River, the Ponte Maria Pia was the first major work to emerge from the French firm of Gustav Eiffel and Company, establishing Eiffel as an important bridge designer and civil engineer of his day. Resting on a parabolic arch spanning 160…
Read MoreA bridge across the Hudson at or near Poughkeepsie was planned starting in the early 1870s to primarily carry coal from the coalfields of northeastern Pennsylvania to New England. At the time there were no bridges between Albany and New York Harbor. Horatio Allen, soon to be President of the…
Read MoreWhen opened in 1909, the Queensboro Bridge had the two longest steel cantilever spans in the world - 1,182 feet from Manhattan to Blackwell's Island and 984 feet from Blackwell's Island to Queens. These would remain the world's longest cantilever spans until the completion of the Quebec Bridge…
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