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38-713: The Harahan Bridge is a cantilevered through truss bridge that carries two rail lines and a pedestrian bridge across the Mississippi River between West Memphis, Arkansas , and Memphis, Tennessee . The bridge is owned and operated by Union Pacific Railroad and is the second longest pedestrian/bicycle bridge in the United States (after the Walkway Over the Hudson in Poughkeepsie, New York). It

76-664: A cantilever bridge. The Forth Bridge is a notable example of an early cantilever bridge. This bridge held the record for longest span in the world for twenty-nine years until it was surpassed by the Quebec Bridge . The engineers responsible for the bridge, Sir Benjamin Baker and Sir John Fowler , demonstrated the structural principles of the suspended span cantilever by sitting in chairs and supporting their colleague, Kaichi Watanabe , in between them, using just their arms and wooden poles. The suspended span, where Watanabe sits,

114-753: A captain in the Union Army during the American Civil War . Harahan married to Mary Kehoe of New Orleans, Louisiana in 1866. Four children were born of this marriage including his son, William Johnson Harahan, who was born in Nashville, Tennessee, on December 22, 1867, and was twice president of the Chesapeake and Ohio Railway ; he died of natural causes in 1937 in Clifton Forge, Virginia. Mary died in 1897. Harahan's second marriage

152-507: A hinge in the girder. Heinrich Gerber was one of the engineers to obtain a patent for a hinged girder (1866) and is recognized as the first to build one. The Hassfurt Bridge over the Main river in Germany with a central span of 124 feet (38 metres) was completed in 1867 and is recognized as the first modern cantilever bridge. The High Bridge of Kentucky by C. Shaler Smith (1877),

190-505: A pin, usually after forcing the union point apart, and when jacks are removed and the bridge decking is added the bridge becomes a truss arch bridge . Such unsupported construction is only possible where appropriate rock is available to support the tension in the upper chord of the span during construction, usually limiting this method to the spanning of narrow canyons. World's longest cantilever bridges (by longest span): James Theodore Harahan James Theodore Harahan (1841–1912)

228-425: A suspended arm. The next span to be complete was between Pier II and Pier III, using temporary falsework wood support timbers driven into the river bottom to hold the fixed span in place until it was complete. The span between Pier III and Pier IV was started concurrently. Span II to III was finished on December 22, 1915. On December 24, 1915, the river rose too quickly and washed away the false work. Span II to III

266-422: A total of 21 barges were needed to complete construction. The next phase of the project involved building massive willow mats. These mats were constructed on the river. When completed, they measured 200 feet x 300 feet. They were floated to the location of the piers (held in place by barges) and sunk to the bottom of the river with rip-rap and stone. The purpose of the willow mats was to reduce scouring, keeping

304-535: A wooden viaduct in Arkansas. The wagonways are still on the bridge, and the Arkansas approach has road stubs leading towards I-55 . ( 35°08′07″N 90°05′07″W  /  35.135142°N 90.085369°W  / 35.135142; -90.085369 ) One of the former roadways on the north side of the bridge is now used to carry pedestrian and bicycle traffic across the Mississippi River. The bridge

342-589: Is 791 feet (241 m) over the main channel on the Memphis side of the river. The bridge carries two rail lines and two roadways. The "Great Bridge," later known as the Frisco Bridge , opened in 1892 and was the first bridge to cross the Mississippi River south of the Ohio River . It was an engineering marvel, carrying a single track across the river. When finished, it was the third longest bridge in

380-648: Is a vital part of a larger project that connects Main Street in Memphis to Broadway in West Memphis, Arkansas . In 2016, it was announced that an anonymous donor had pledged $ 5 million to illuminate the bridge. The Harahan Bridge became the second illuminated bridge in Memphis, the only one to be illuminated by LED (although plans are in the works to re-light the Hernando de Soto Bridge upstream with LED's). Cantilever bridge The steel truss cantilever bridge

418-505: Is formed by two cantilever arms extending from opposite sides of an obstacle to be crossed, meeting at the center. In a common variant, the suspended span , the cantilever arms do not meet in the center; instead, they support a central truss bridge which rests on the ends of the cantilever arms. The suspended span may be built off-site and lifted into place, or constructed in place using special travelling supports. A common way to construct steel truss and prestressed concrete cantilever spans

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456-424: Is in the center. The wooden poles resist the compression of the lower chord , while the outstretched arms support the tension of the upper chord. The placement of the brick counterweights demonstrates the action of the outer foundations. Cantilever Bridge.—A structure at least one portion of which acts as an anchorage for sustaining another portion which extends beyond the supporting pier. A simple cantilever span

494-405: Is to counterbalance each cantilever arm with another cantilever arm projecting the opposite direction, forming a balanced cantilever ; when they attach to a solid foundation, the counterbalancing arms are called anchor arms . Thus, in a bridge built on two foundation piers, there are four cantilever arms: two which span the obstacle, and two anchor arms that extend away from the obstacle. Because of

532-508: The Illinois Central Railroad , who was killed in a railroad accident during the construction of the bridge. In February 2011, Union Pacific Railroad officials agreed to the idea of converting the 1917 roadways into a bicycle-pedestrian walkway across the river. In June 2012, Memphis was awarded a $ 14.9 million federal grant to build the walkway. The overall project was expected to cost $ 30 million, of which about $ 11 million

570-547: The Niagara Cantilever Bridge by Charles Conrad Schneider (1883) and the Poughkeepsie Bridge by John Francis O'Rourke and Pomeroy P. Dickinson (1889) were all important early uses of the cantilever design. The Kentucky River Bridge spanned a gorge that was 275 feet (84 metres) deep and took full advantage of the fact that falsework, or temporary support, is not needed for the main span of

608-509: The Memphis business community, and political leaders were urged to present a bill to Congress for approval of the ambitious project. This plan estimated the cost at $ 2.6 million and would include $ 400,000 for wagonways along each side. Initially, developers of the Rock Island Railroad were not interested in providing vehicular access to their bridge. Newly elected Congressman Kenneth McKellar from Memphis threatened to block

646-519: The Mississippi river crossing. Congressman McKellar led a bipartisan majority to approve the bill. Leaders in Arkansas resented Memphis dealing with the railroad without their involvement. This was the first attempt in a long running feud over the bridge. Arkansas wanted a "toll-free" bridge that would accommodate trolley lines. In August 1912, a mass meeting was held in Marion, Arkansas . There,

684-488: The Rock Island Railroad agreed to build a $ 4 million bridge with wagonways that would be turned over to Crittenden County and the City of Memphis, to be used "without toll for all time." On April 10, 1913, Ralph Modjeski was instructed to prepare plans for the bridge in Memphis. A "force" of draftsmen was employed to detail drawings for the substructure and superstructure of the bridge. On May 13, 1913, plans were submitted by

722-470: The bridge permit if wagonways were not included. This bill also met with opposition in the form of Democratic party leader Oscar Underwood of Alabama. Congressman Underwood's campaign manager, Edward Campbell, was attorney for the Kansas City, Memphis and Birmingham Railroad , which was the owner of the "Great Bridge." The KCM&B Railroad did not want a competing bridge to undermine its monopoly on

760-523: The caisson, it also left quite a mess on the top of it and any barges nearby. As the caissons were being sunk into the riverbed, the piers were being built on top of them, adding weight and driving the caisson deeper into the river bottom. The piers were masonry blocks of granite backed with concrete. The piers of the Harahan were located directly upstream of the piers of the Frisco Bridge to keep

798-593: The end of the bridge to the St. Francis Levee. The total distance from the levee to the South Memphis bluffs was 16,295 feet (4,967 m); only 1,194 feet (364 m) lay in Memphis, Tennessee. The Harahan Bridge was originally to be named the Rock Island Bridge but was named for James Theodore Harahan , who was president of the Illinois Central Railroad at the time before his untimely death. Harahan

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836-410: The girder or truss and meant that longer spans could be built. Several 19th-century engineers patented continuous bridges with hinge points mid-span. The use of a hinge in the multi-span system presented the advantages of a statically determinate system and of a bridge that could handle differential settlement of the foundations. Engineers could more easily calculate the forces and stresses with

874-547: The navigation channels open to river traffic. Pier IV was moved 17 feet (5.2 m) toward the river relative to the Frisco Pier IV. This enabled the engineers to design two suspended spans and three cantilevered arms identically. With the caissons sunk and the substructure complete, work began on the steel superstructure. The longest span between Pier I and Pier II was the first to be built. This span would be built without falsework, employing two cantilevered arms and

912-411: The need for more strength at the balanced cantilever's supports, the bridge superstructure often takes the form of towers above the foundation piers. The Commodore Barry Bridge is an example of this type of cantilever bridge. Steel truss cantilevers support loads by tension of the upper members and compression of the lower ones. Commonly, the structure distributes the tension via the anchor arms to

950-609: The outermost supports, while the compression is carried to the foundations beneath the central towers. Many truss cantilever bridges use pinned joints and are therefore statically determinate with no members carrying mixed loads. Prestressed concrete balanced cantilever bridges are often built using segmental construction . Some steel arch bridges (such as the Navajo Bridge ) are built using pure cantilever spans from each side, with neither falsework below nor temporary supporting towers and cables above. These are then joined with

988-491: The railroad to the U.S. Engineer for approval by the war department. Of the Harahan's total length of 4,972 feet (1,515 m), 1,194 feet (364 m) lie in Tennessee, and 3,778 feet (1,152 m) lie in Arkansas. This was based on the state line being set in the center of the Mississippi river at low water. This disparity on ownership and maintenance was further exacerbated by the addition of 2.5 miles (4.0 km) from

1026-523: The river bed in place as the pneumatic caissons were dug into the river bed. The Harahan Bridge was to be located 200 feet (61 m) north of the Frisco Bridge. Use of pneumatic caissons had been used on the Frisco and other major bridges; this did not eliminate the dangers involved. The Harahan pneumatic caissons were constructed on shore out of wood. The walls were 3 feet (0.91 m) thick, with heavy caulking and tar to make them airtight. The caisson

1064-614: The world, but within 20 years of its opening, rail traffic had increased so much that another bridge was needed. Mayor E.H. Crump met with officials from the Rock Island Railroad on February 5, 1912, to discuss the possibility of a new bridge. The Iron Mountain Railroad and the Cotton Belt Railroad joined and formed the Memphis and Arkansas Bridge and Terminal Company. The plan drew wide support from

1102-470: Was 40 feet wide x 90 feet long x 60 feet tall. In reality, it was a large wooden box, open at the bottom. The chamber at the bottom of the caisson had a 7-foot ceiling for the sandhogs to work. Digging the river bottoms to sink the caissons into the river bed was difficult and dangerous work. All the material inside the walls of the caisson had to be removed to the surface. The caisson was built with excavation shafts for removing dirt and clay. The pressure

1140-409: Was a major engineering breakthrough when first put into practice, as it can span distances of over 1,500 feet (450 m), and can be more easily constructed at difficult crossings by virtue of using little or no falsework . Engineers in the 19th century understood that a bridge that was continuous across multiple supports would distribute the loads among them. This would result in lower stresses in

1178-557: Was an American businessman. He was the president of the Illinois Central Railroad from 1906 to 1911. Harahan was born on January 12, 1841, in Lowell, Massachusetts , the son of Thomas Harahan and Ann née McCuen of Scotch-Irish ancestry, both immigrants from Ireland. Harahan worked for railroad companies as a young man, including as a brakeman, eventually becoming president of the Illinois Central Railroad from November 7, 1906, to 1911, succeeding Stuyvesant Fish . Harahan served as

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1216-458: Was built with roadways cantilevered off the sides of the main structure for vehicles. These roadways are owned by the cities of Memphis, Tennessee, and Crittenden County, Arkansas , and were used from 1917–1949, until the Memphis & Arkansas Bridge opened 400 feet (120 m) south of the Harahan. The bridge was named in honor of railroad executive James Theodore Harahan , former president of

1254-421: Was increased to match the water pressure, keeping the river water out of the work area. When the pressure was high enough, the excavation shafts were opened and air pressure would remove the light weight river bottom in a "blow off." This eased the process greatly and saved a tremendous amount of time and effort for the sand hogs . It did, however, make a spectacular sight as a fountain of river bottom erupted from

1292-549: Was killed in a railroad accident on January 22, 1912 while traveling to Memphis on his private rail car to meet about the construction of the bridge. The first work was to build 2 miles (3.2 km) of track from an existing line in the Arkansas flood plains to bring materials in place for construction. When this track was complete, 60 cars of timber waited for delivery. This material was used in building barges used for construction and moving materials into place. The first three months of construction were used to build 15 barges, and

1330-514: Was later named Harahan Bridge when it opened in 1914. The four men were sleeping in the private car which was at the end of the train. They were struck from behind by the engine of Train No. 3, The Seminole Limited . The locomotive pulling Harahan's car was previously driven by legendary railroad engineer Casey Jones during the fatal collision of April 30, 1900, in Vaughn, Mississippi, in which Jones

1368-458: Was not damaged, although it moved 8 inches (20 cm). Span III to IV was completely washed out, forcing a delay in the construction and a redesign on the span. On July 14, 1916, the first train crossed the bridge. The celebration that had been planned was cancelled due to the war in Europe. The wagonways were not opened until September 17, 1917. The delay was due to construction problems with

1406-463: Was to Mary N. Mallory of Montgomery County, Tennessee on April 14, 1899. James Harahan was killed in a train accident, in his own private railroad car, on January 22, 1912, in Kinmundy, Illinois , while en route to Memphis, Tennessee, with three other railroad executives. They were traveling to a meeting to discuss the building of a railroad bridge across the Mississippi River at Memphis. The bridge

1444-528: Was used for the Harahan Bridge portion. Construction was completed in 2016. The Harahan Bridge is in total 4,973 feet (1,516 m) long while the main bridge is 2,550 feet (780 m) from the east anchorage on the Memphis Bluffs to Pier 5 on the Arkansas flood plains. An additional 2,363 feet (720 m) tower and girder viaduct completes the bridge to the west abutment. The longest span

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