A swing bridge is a movable bridge that has as its primary structural support a vertical locating pin and support ring, usually at or near to its center of gravity, about which the turning span can then pivot horizontally as shown in the animated illustration to the right. Small swing bridges as found over canals may be pivoted only at one end, opening as would a gate, but require substantial underground structure to support the pivot.
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 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.
The Jones and Laughlin Steel Company began as the American Iron Company, founded in 1852 by Bernard Lauth and B. F. Jones, a few miles south of Pittsburgh along the Monongahela River. Lauth's interest was bought in 1854 by James H. Laughlin. The first firm to bear the name of Jones and Laughlin was organized in 1861 and headquartered at Third & Ross in downtown Pittsburgh. Katharine Hepburn's maternal uncle, Frank Garlinghouse, was a longtime engineer for J&L Steel.
The Wisconsin Bridge and Iron Company (WB&I) is, or was, a fabricator and erector of iron and steel bridges and other large structures.
The Cambria Iron Company of Johnstown, Pennsylvania was a major 19th-century industrial producer of iron and steel. Founded in 1852, it had the nation's largest steel foundry in the 1870s, and was renamed the Cambria Steel Company in 1898. The company used many innovations in the steelmaking process, including those of William Kelly and Henry Bessemer. The company was acquired in 1923 by the Bethlehem Steel Company. The company's historic facilities, extending some 12 miles (19 km) along the Conemaugh and Little Conemaugh Rivers, are a National Historic Landmark District.
The King Iron Bridge & Manufacturing Company was a late-19th-century bridge building company located in Cleveland, Ohio. It was founded by Zenas King (1818–1892) in 1858 and subsequently managed by his sons, James A. King and Harry W. King and then his grandson, Norman C. King, until the mid-1920s. Many of the bridges built by the company were used during America's expansion west in the late 19th century and early 20th century, and some of these bridges are still standing today.
The Western Bridge and Construction Company of Omaha, Nebraska was one of the foremost bridge engineering and manufacturing companies in the Midwestern United States. Several of their bridges are now listed on the National Register of Historic Places. Their headquarters were located in the Bee Building in Downtown Omaha.
The Keystone Bridge Company, founded in 1865 by Andrew Carnegie, was an American bridge building company. It was one of the 28 companies absorbed into the American Bridge Company in 1900. The company advertised its services for building steel, wrought iron, wooden railway and road bridges. It held a patent for wrought iron bridges and also supplied wrought iron columns for buildings. Thomas Carnegie worked for Keystone Bridge as treasurer for roughly 20 years, from the founding of the company until his death in 1886.
The Lilley Road—Lower Rouge River Bridge is an automotive bridge located on Lilley Road over the Lower River Rouge in Canton Township, Michigan. It was listed on the National Register of Historic Places in 2000.
Canton Bridge Company was a firm that was later incorporated into the American Bridge Company. The firm was established in Canton, Ohio in 1892 and became one of the nation's biggest bridge-builders during the early 20th century. It designed and/or built many bridges that later became listed on the U.S. National Register of Historic Places (NRHP).
The Washington Mill Bridge is a road bridge crossing Lytle Creek near Bernard, Iowa that was built in 1877–78. It is a bowstring, through arch bridge, manufactured and built by the Massillon Bridge Company.
The Fremont Mill Bridge near Anamosa, Iowa was built in 1873. Its superstructure was designed and built by Massillon Iron Bridge Company and its foundations were built by James Milne. It is a wrought iron bowstring through arch bridge.
The Iowa Bridge Company was a company that designed and built many bridges that are listed on the U.S. National Register of Historic Places.
The County Road 557–West Branch Escanaba River Bridge is a bridge located on County Road 557 as it passes over the West Branch of the Escanaba River in Wells Township in Marquette County, Michigan. It was listed on the National Register of Historic Places in 1999.
The Champion Bridge Company, formerly known as Champion Iron Bridge and Manufacturing Company, is a steel fabrication business based in Wilmington, Ohio, in the United States. It has been in business since the 1870s, and several of its works are listed on the National Register of Historic Places.
The Illinois Steel Company was an American steel producer with five plants in Illinois and Wisconsin. Founded through a consolidation in 1889, Illinois Steel grew to become the largest steel producer in the United States. In 1898, several other steel and transportation companies were merged into it to form the Federal Steel Company, itself merged into U.S. Steel in 1901.
The Mill Creek Bridge is located north of Cherokee, Iowa, United States. It spans Mill Creek for 207 feet (63 m). On June 24, 1891 a disastrous flood along the Little Sioux River and its tributaries wiped out nearly every bridge in Cherokee County. The following month the county board of supervisors signed a contract with the George E. King Bridge Co. of Des Moines for 17,650 to replace the bridges. This Pratt truss bridge was fabricated by the King Bridge Company of Cleveland, Ohio. It and a similar span over Mill Creek near Larrabee are the only two that remain. This bridge was listed on the National Register of Historic Places in 1998. A modern concrete span, built just upstream in 2006, now carries the road. The old bridge is closed to vehicular traffic.
The Marantette Bridge, also known as the Railroad Street Bridge, is a historic vehicle bridge, now closed to traffic, located at Railroad Street over the St. Joseph River in Mendon, Michigan. It was listed on the National Register of Historic Places in 2001.
The Valley Railway was a shortline railroad which operated between the city of Cleveland and small town of Zoarville in the state of Ohio in the United States. The railroad was founded in 1871, but the first segment of track did not open until 1880 and the line was not completed until 1884. The Baltimore and Ohio Railroad (B&O) obtained a controlling interest in the Valley Railway in 1890. The railroad went bankrupt in 1895, at which time it was reorganized as the Cleveland, Terminal and Valley Railway (CT&V). The B&O took over operation of the CT&V in 1909, and the company was merged with the B&O in 1915.
The Station Road Bridge, near Brecksville, Ohio, was built in 1882. It spans the Cuyahoga River between Cuyahoga County and Summit County, Ohio. It was listed on the National Register of Historic Places in 1979.
