Misplaced Pages

#573426

49-575: The Cochrane–Africatown USA Bridge is a cable-stayed bridge carrying US 90 / US 98 Truck across the Mobile River from the mainland to Blakeley Island in Mobile, Alabama . The Cochrane–Africatown USA Bridge was completed and opened in 1991. It was named in honor of the 60-year-old vertical-lift Cochrane Bridge (in turn named for president of the Mobile, Alabama Chamber of Commerce at

98-516: A clear span of 1,224 feet (373 m). The anchorage and stone towers were completed, and the cable wire delivered along with the material for the superstructure, when the railway company became insolvent. The bridge construction was halted and he was never able to complete it. What is now known as the High Bridge was later completed as the first cantilever bridge in the US, with a truss for carrying

147-460: A 2-span or 3-span cable-stayed bridge, the loads from the main spans are normally anchored back near the end abutments by stays in the end spans. For more spans, this is not the case and the bridge structure is less stiff overall. This can create difficulties in both the design of the deck and the pylons. Examples of multiple-span structures in which this is the case include Ting Kau Bridge , where additional 'cross-bracing' stays are used to stabilise

196-507: A huge 80-ton wire rope machine and founded the town of Roebling, New Jersey . Here the John A. Roebling's Sons company steel mill was built. His granddaughter Emily Roebling Cadwalader was a married Philadelphia socialite noted as the owner of historic yachts . His grandson Washington A. Roebling II died as a passenger on the RMS ; Titanic . His great-grandson Donald Roebling was

245-707: A main span of 1,057 feet (322 m), at the time it was finished. In 1867, Roebling started design work on what is now called the Brooklyn Bridge , spanning the East River in New York. On June 28, 1869, at Fulton Ferry , while he was standing at the edge of a dock, working on fixing the location where the bridge would be built, his foot was crushed by an arriving ferry. His injured toes were amputated. He refused further medical treatment and wanted to cure his foot by " water therapy " (continuous pouring of water over

294-683: A poor merchant in the town, and his oldest brother Herman Christian Roebling prepared to take over the tobacco shop. As noted earlier, Roebling and his brother Carl immigrated to the United States, settling first in Pennsylvania. John Roebling and Johanna Herting had nine children: Roebling's son Washington and his daughter-in-law Emily Warren Roebling continued his work on the Brooklyn Bridge. His son Ferdinand expanded his wire rope business. His son Charles designed and invented

343-553: A seven-strand wire rope at a ropewalk that he built on his farm. In 1841, Roebling began producing wire rope at Saxonburg to use in suspension bridges and such projects as the portage railroad. In 1844 Roebling won a bid to replace the wooden canal aqueduct across the Allegheny River with the Allegheny Aqueduct . His design encompassed seven spans of 163 feet (50 m), each consisting of a wooden trunk to hold

392-593: A single bridge of the kind be put up in Philadelphia, exhibiting all the beautiful forms of the system to full advantage, and it needs no prophecy to foretell the effect which the novel and useful features will produce upon the intelligent minds of the Americans. At that time, canal boats from Philadelphia were transported over the Allegheny Mountains on railroad cars in order to access waterways on

441-519: A temporary halt to Roebling's work, as resources were diverted to the war effort. In 1863 building resumed on a bridge over the Ohio River at Cincinnati , which Roebling had started in 1856 and halted due to lack of financing. He finished this bridge in 1867. The Cincinnati-Covington Bridge, later named the John A. Roebling Suspension Bridge in his honor, was the world's longest suspension bridge, with

490-777: A young age, Roebling's mother arranged for him to be tutored in mathematics and science at Erfurt by Ephraim Salomon Unger. He went to Erfurt when he was 15. In 1824 he passed his Surveyor's examination and returned home for a year. In 1824 he enrolled for two semesters at the Bauakademie in Berlin , where he studied architecture and engineering under Martin Friedrich Rabe (1765–1856), bridge construction and foundation construction under Johann Friedrich Dietlein (1782–1837), hydraulics under Johann Albert Eytelwein (1764–1848), and languages. Roebling also attended lectures of

539-616: Is a cable-stayed bridge with a more substantial bridge deck that, being stiffer and stronger, allows the cables to be omitted close to the tower and for the towers to be lower in proportion to the span. The first extradosed bridges were the Ganter Bridge and Sunniberg Bridge in Switzerland. The first extradosed bridge in the United States, the Pearl Harbor Memorial Bridge was built to carry I-95 across

SECTION 10

#1732802045574

588-443: Is optimal for spans longer than cantilever bridges and shorter than suspension bridges. This is the range within which cantilever bridges would rapidly grow heavier, and suspension bridge cabling would be more costly. Cable-stayed bridges were being designed and constructed by the late 16th century, and the form found wide use in the late 19th century. Early examples, including the Brooklyn Bridge , often combined features from both

637-603: The Delaware and Hudson Canal . During this period, he moved to Trenton, New Jersey . In Trenton, Roebling built a large industrial complex for wire production for his growing company: John A. Roebling's Sons Company. This complex inspired Trenton's motto that appears on the Lower Trenton Bridge : "Trenton Makes, the World Takes". Roebling's next project, starting in 1851, was a railroad bridge connecting

686-745: The Golden Gate Bridge in San Francisco, California, constructed from 1933 to 1937. The Golden Gate Bridge was and still is a technical engineering marvel that Roebling, posthumously, has his footprint on. Kinkora Works , the site of the Roebling Company factory complex in Roebling, New Jersey was opened as a museum in 2010. The museum tells the story of the Roebling family and the John A. Roebling’s Sons Company. Roebling

735-852: The National Register of Historic Places . Volkert and Associates, Inc. design for the bridge earned it the Outstanding Engineering Achievement in the U.S.A. Award from the National Society of Professional Engineers and the Award of Excellence in Highway Design from the Federal Highway Administration , both in 1992. This was the first, and is still the only, cable-stayed bridge in the state of Alabama. The bridge

784-670: The New York Central and Great Western Railway of Canada over the Niagara River . Construction took four years. The bridge, with a clear span of 825 feet (251 m), was supported by four, ten-inch (25 cm) wire cables, and had two levels, one for vehicles and one for rail traffic. While the Niagara bridge was being built, Roebling designed a railway suspension bridge across the Kentucky River , which required

833-608: The Penobscot Narrows Bridge , completed in 2006, and the Veterans' Glass City Skyway , completed in 2007. A self-anchored suspension bridge has some similarity in principle to the cable-stayed type in that tension forces that prevent the deck from dropping are converted into compression forces vertically in the tower and horizontally along the deck structure. It is also related to the suspension bridge in having arcuate main cables with suspender cables, although

882-486: The Theodor Heuss Bridge (1958). However, this involves substantial erection costs, and more modern structures tend to use many more cables to ensure greater economy. Cable-stayed bridges may appear to be similar to suspension bridges , but they are quite different in principle and construction. In suspension bridges, large main cables (normally two) hang between the towers and are anchored at each end to

931-451: The live load of traffic crossing the bridge. The tension on the main cables is transferred to the ground at the anchorages and by downwards compression on the towers. In cable-stayed bridges, the towers are the primary load-bearing structures that transmit the bridge loads to the ground. A cantilever approach is often used to support the bridge deck near the towers, but lengths further from them are supported by cables running directly to

980-507: The Donzère-Mondragon canal at Pierrelatte is one of the first of the modern type, but had little influence on later development. The steel-decked Strömsund Bridge designed by Franz Dischinger (1955) is, therefore, more often cited as the first modern cable-stayed bridge. Other key pioneers included Fabrizio de Miranda , Riccardo Morandi , and Fritz Leonhardt . Early bridges from this period used very few stay cables, as in

1029-636: The Quinnipiac River in New Haven, Connecticut, opening in June 2012. A cradle system carries the strands within the stays from the bridge deck to bridge deck, as a continuous element, eliminating anchorages in the pylons. Each epoxy-coated steel strand is carried inside the cradle in a one-inch (2.54 cm) steel tube. Each strand acts independently, allowing for removal, inspection, and replacement of individual strands. The first two such bridges are

SECTION 20

#1732802045574

1078-409: The bridge deck. A distinctive feature are the cables or stays , which run directly from the tower to the deck, normally forming a fan-like pattern or a series of parallel lines. This is in contrast to the modern suspension bridge , where the cables supporting the deck are suspended vertically from the main cable, anchored at both ends of the bridge and running between the towers. The cable-stayed bridge

1127-405: The cable-stayed and suspension designs. Cable-stayed designs fell from favor in the early 20th century as larger gaps were bridged using pure suspension designs, and shorter ones using various systems built of reinforced concrete . It returned to prominence in the later 20th century when the combination of new materials, larger construction machinery, and the need to replace older bridges all lowered

1176-562: The cable-stayed bridge are balanced so that the supporting towers do not tend to tilt or slide and so must only resist horizontal forces from the live loads. The following are key advantages of the cable-stayed form: There are four major classes of rigging on cable-stayed bridges: mono , harp , fan, and star . There are also seven main arrangements for support columns: single , double , portal , A-shaped , H-shaped , inverted Y and M-shaped . The last three are hybrid arrangements that combine two arrangements into one. Depending on

1225-693: The combination of technologies created a stiffer bridge. John A. Roebling took particular advantage of this to limit deformations due to railway loads in the Niagara Falls Suspension Bridge . The earliest known surviving example of a true cable-stayed bridge in the United States is E.E. Runyon's largely intact steel or iron Bluff Dale Suspension bridge with wooden stringers and decking in Bluff Dale, Texas (1890), or his weeks earlier but ruined Barton Creek Bridge between Huckabay, Texas and Gordon, Texas (1889 or 1890). In

1274-572: The design, the columns may be vertical or angled or curved relative to the bridge deck. A side-spar cable-stayed bridge uses a central tower supported only on one side. This design allows the construction of a curved bridge. Far more radical in its structure, the Puente del Alamillo (1992) uses a single cantilever spar on one side of the span, with cables on one side only to support the bridge deck. Unlike other cable-stayed types, this bridge exerts considerable overturning force upon its foundation and

1323-654: The examination. On May 22, 1831, Roebling left Prussia with a group of emigrants bound for the United States. They included his brother Carl and the older Johann Adolphus Etzler , who believed in a technological utopia . Engineers had difficulty advancing and achieving economic mobility in Prussian society, in part because of the Napoleonic Wars , which had lasted until 1815, and suppressed investment in infrastructure. During this period, Prussia also had considerable political unrest, as authoritarian governments took

1372-436: The ground. This can be difficult to implement when ground conditions are poor. The main cables, which are free to move on bearings in the towers, bear the load of the bridge deck. Before the deck is installed, the cables are under tension from their own weight. Along the main cables smaller cables or rods connect to the bridge deck, which is lifted in sections. As this is done, the tension in the cables increases, as it does with

1421-421: The load between the cables and the stays . Roebling added a large safety factor to the divided loads and then solved for the forces. This approach gave a sufficiently accurate analysis of the structure given the assumption that the structure was sufficiently ductile to handle the resulting deformation (Buonopane, 2006). Roebling's company John A Roebling's Sons Co. is credited with being the cable contractor for

1470-470: The next season's crops. But by the 1840s, the economy was improving and many Americans believed in the nation's manifest destiny to extend its borders and achieve greatness on the North American continent. Transportation between eastern industrial hubs and frontier farming markets had become a matter of both national and popular interest. Many railway and transportation projects were under way near

1519-598: The other settlers had remained with Etzler. In 20th-century recognition of his historic importance, the John Roebling House at Saxonburg was listed on the National Register of Historic Places in 1976. When the Roeblings and others arrived, the United States was in the later stages of an economic boom, which ended in the financial Panic of 1837 , reducing everyone's opportunities. Farmers were deeply affected by it as they often depended on credit to produce

Cochrane–Africatown USA Bridge - Misplaced Pages Continue

1568-596: The other side of the mountains, so that the boats could continue to Pittsburgh. The system of inclines and levels that moved the boats and conventional railroad cars was a state-owned enterprise, the Allegheny Portage Railroad . The railroad cars were pulled up and down the inclines by a long loop of thick hemp rope, up to 7 centimetres thick. The hemp ropes were expensive and had to be replaced frequently. Roebling remembered an article he had read about wire rope . Soon after, he started developing

1617-683: The philosopher Georg Wilhelm Friedrich Hegel . He developed an interest in natural philosophy, and many years later worked on a 1000-page treatise on his own concepts of the universe. In 1825 Roebling got a government job in the Arnsberg province and moved to Eslohe , where he worked for four years on designing and supervising construction of military roads. During this period he made sketches for suspension bridges over Ruhr - and Lenne -river, which were never built. In 1829 he returned to his home to work out his final thesis and prepare for his second engineer examination. For unknown reasons, he never took

1666-464: The places of democratic ones. Etzler believed that they could create a technological utopia in the United States, but disputes arose among the men en route. The group split up after reaching Pennsylvania . John and Carl Roebling purchased 1,582 acres (640 hectares) of land on October 28, 1831, in Butler County with the intent to establish a German settlement, to be called Saxonburg . Most of

1715-526: The project and it was completed in 1883. John Roebling is buried in the Riverview Cemetery in Trenton, New Jersey . Roebling devised "an equilibrium strength approach, in which equilibrium is always satisfied but compatibility of deformations is not enforced." This was essentially an approximation method similar to the force method: First, Roebling computed the dead and live loads, then divided

1764-547: The pylons; Millau Viaduct and Mezcala Bridge , where twin-legged towers are used; and General Rafael Urdaneta Bridge , where very stiff multi-legged frame towers were adopted. A similar situation with a suspension bridge is found at both the Great Seto Bridge and San Francisco–Oakland Bay Bridge where additional anchorage piers are required after every set of three suspension spans – this solution can also be adapted for cable-stayed bridges. An extradosed bridge

1813-618: The railway track . A second version was built on the same foundations in 1911. The highest railroad bridge over a navigable river in the United States, the bridge is still in use. In 1859 Roebling completed another suspension bridge at Pittsburgh over the Allegheny River. Its total length was 1,030 feet (314m), consisting of two main spans of 344 feet (105m) each, and two side spans of 171 feet (52m) each. His son Washington Roebling worked with him on that project, having completed his engineering degree. The American Civil War brought

1862-517: The relative price of these designs. Cable-stayed bridges date back to 1595, where designs were found in Machinae Novae , a book by Croatian - Venetian inventor Fausto Veranzio . Many early suspension bridges were cable-stayed construction, including the 1817 footbridge Dryburgh Abbey Bridge , James Dredge 's patented Victoria Bridge, Bath (1836), and the later Albert Bridge (1872) and Brooklyn Bridge (1883). Their designers found that

1911-519: The self-anchored type lacks the heavy cable anchorages of the ordinary suspension bridge. Unlike either a cable-stayed bridge or a suspension bridge, the self-anchored suspension bridge must be supported by falsework during construction and so it is more expensive to construct. John A. Roebling Röbling was born June 12, 1806 in Mühlhausen to Friederike Dorothea (née Muelleren) and Christoph Polykarpus Röbling. Recognizing his intelligence at

1960-507: The site which Roebling chose for his colony, but instead of continuing in the engineering profession, he took up farming. After five years he married Johanna Herting, a tailor's daughter. He found agrarian work unsatisfying, and Saxonburg attracted few settlers. In 1837, after the birth of his first child and the death of his brother Carl, Roebling returned to engineering for work. He first worked on projects to improve river navigation and build canals . For three years, he conducted surveys for

2009-512: The spar must resist the bending caused by the cables, as the cable forces are not balanced by opposing cables. The spar of this particular bridge forms the gnomon of a large garden sundial . Related bridges by the architect Santiago Calatrava include the Puente de la Mujer (2001), Sundial Bridge (2004), Chords Bridge (2008), and Assut de l'Or Bridge (2008). Cable-stayed bridges with more than three spans involve significantly more challenging designs than do 2-span or 3-span structures. In

Cochrane–Africatown USA Bridge - Misplaced Pages Continue

2058-573: The state of Pennsylvania for railway lines across the Allegheny Mountains , from the capital, Harrisburg , to Pittsburgh in the far west, at the start of the Ohio River . In 1840, Roebling wrote to suspension bridge designer Charles Ellet Jr. , offering to help with the design of a bridge near Philadelphia : The study of suspension bridges formed for the last few years of my residence in Europe my favourite occupation ... Let but

2107-485: The time, John T. Cochrane, Sr.) that it replaced, and the historic community of Africatown , which was located where the western approach to the bridge was built. In 1997 community activists promoted preservation and designation of the Africatown Historic District to encourage development there. The district was included on Mobile's African American Heritage Trail in 2009. In 2012 it was added to

2156-411: The towers. That has the disadvantage, unlike for the suspension bridge, that the cables pull to the sides as opposed to directly up, which requires the bridge deck to be stronger to resist the resulting horizontal compression loads, but it has the advantage of not requiring firm anchorages to resist the horizontal pull of the main cables of the suspension bridge. By design, all static horizontal forces of

2205-529: The twentieth century, early examples of cable-stayed bridges included A. Gisclard's unusual Cassagnes bridge (1899), in which the horizontal part of the cable forces is balanced by a separate horizontal tie cable, preventing significant compression in the deck, and G. Leinekugel le Coq's bridge at Lézardrieux in Brittany (1924). Eduardo Torroja designed a cable-stayed aqueduct at Tempul in 1926. Albert Caquot 's 1952 concrete-decked cable-stayed bridge over

2254-539: The water, supported by a continuous cable made of many parallel wires, wrapped tightly together, on each side of the trunk. He followed this innovation in 1845 by building a suspension bridge over the Monongahela River at Pittsburgh. The confluence of the Allegheny and Monongahela rivers at Pittsburgh forms the Ohio River . In 1848, Roebling undertook the construction of four suspension aqueducts on

2303-481: The wound). His condition deteriorated. He died on July 22, 1869, of tetanus at the home of his son on Hicks Street , in Brooklyn Heights . It was 24 days after the accident. His son Washington Roebling was later named chief engineer of the project, but due to his further incapacity to work after suffering from 'the bends' while in a caisson on the river bed, his wife Emily Warren Roebling took over

2352-606: Was damaged on August 29, 2005, when Hurricane Katrina broke a 13,000-ton semi-submersible platform , the PSS Chemul, free from drydock and wedged it under the bridge. The bridge remained in service and continued to carry two lanes of traffic after the storm. This article about a bridge in Alabama is a stub . You can help Misplaced Pages by expanding it . Cable-stayed bridge A cable-stayed bridge has one or more towers (or pylons ), from which cables support

2401-535: Was the youngest of four children. He was baptized in the Lutheran church Divi Blasii in Mühlhausen . As a young boy he played the bass clarinet and the french horn . He also exhibited great artistic talent for sketches and paintings. His father owned a small tobacco shop, but the business was insufficient to provide livelihood for all three sons. Roebling's sister Friederike Amalie married Carl August Meissner,

#573426