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36-585: The Manchac Swamp Bridge is a twin concrete trestle bridge near Manchac in the U.S. state of Louisiana . It carries Interstate 55 and U.S. Route 51 over the Manchac Swamp in Louisiana and represents a third of the highway's approximately 66 miles (106 km) in Louisiana. With a total length of 22.80 miles (36.69 km), it is one of the longest bridges in the world over water , and

72-418: A design capacity of 250,000 cu ft/s when all 350 bays are fully open, or approximately 714 cu ft/s per bay. There are two cemeteries located in the spillway. The cemeteries contain the remains of enslaved persons of African descent and free African-Americans, and the historic ground surface is under several feet of sediment. When the spillway gates are opened, the cemeteries are flooded. The location of

108-477: A design capacity of 250,000 cu ft/s (7,100 m /s). The spillway is crossed by U.S. 61 and Interstate 10 . The spillway's secondary function is as a recreational area. It is used for off-road vehicles, biking, boating, hiking, hunting, and fishing. It is designated a protected wildlife management area by the Louisiana Department of Wildlife and Fisheries . To enhance fishing in

144-450: A floodway that transfers the diverted flood waters to the lake. The control structure, located between the towns of Montz and Norco , is a mechanically controlled concrete weir that extends for over a mile and a half parallel to the river. When opened, the control structure allows overflow volume to flow into Lake Pontchartrain. The lake's opening to the gulf is sufficient to absorb and dissipate any conceivable volume of flood flow. Thus,

180-485: A trestle from which to dump the fill. Timber trestles remain common in some applications, most notably for bridge approaches crossing floodways , where earth fill would dangerously obstruct floodwater. For the purposes of discharging material below, a coal trestle carried a dead-end track, rather than a bridge. One of the longest trestle spans created was for railroad traffic crossing the Great Salt Lake on

216-675: A wooden trestle. Being less susceptible to fire damage in this brushy location is also an advantage. The approaches to the Kate Shelley High Bridge near Boone, Iowa, are steel trestles. New Orleans utilizes steel trestles to support parts of I-10 , the Pontchartrain Expressway , and Tulane Avenue . Also, trestles support the elevated railroad leading to and from the Huey P. Long Bridge . The first major prestressed concrete trestle railroad bridge built

252-435: Is also resilient to the stresses imposed. The structure also naturally leads to a certain redundancy (provided that economic considerations are not overly dominant). Such wooden coasters, while limited in their path (not supporting loops), possess a certain ride character (owing to structural response) that is appreciated by fans of the type. The Camas Prairie Railroad in northern Idaho utilized many timber trestles across

288-510: Is done by two rail-mounted gantry cranes atop the spillway. The number of needles removed determines the water flow into the spillway. Gaps built into each bay allow limited seepage anytime the river level reaches the bottom of the bays. Removal of all 7000 needles takes about 36 hours but is usually done over a period of several days. The spillway is part of the United States Army Corps of Engineers ' multi-state plan, called

324-579: Is the longest bridge on the Interstate Highway System , and some claim it is the longest toll-free road bridge in the world. Opened in 1979, with piles driven 250 feet (76 m) beneath the swamp, it cost $ 7 million per mile ($ 4.3 million/km), equivalent to $ 23.7 million per mile ($ 15 million/km) in 2023, to construct. The 2023 Manchac Swamp Bridge Car Crash occurred on October 23, 2023, on Interstate 55 in St. John

360-487: Is unknown. The sites adjoin 19th- and early 20th-century sugar plantations in St. Charles Parish. According to oral histories and as confirmed by GIS analysis, both cemeteries were located in the midst of the cane fields of their respective plantations. The Kenner Cemetery, located on the former Roseland Plantation, was reported to be marked by iron and wooden crosses during its period of use. No such markers were confirmed archaeologically, but one granite US veteran headstone

396-680: The Gulf of Mexico . The spillway was constructed between 1929 and 1931, following the Great Mississippi Flood of 1927 , and has been designated as a National Historic Civil Engineering Landmark by the American Society of Civil Engineers . The Bonnet Carré Crevasse was one of several levee breaches in the Bonnet Carré area in 1871. Local drainage systems were unable to contain the floodwater and strong winds caused

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432-512: The Lucin Cutoff in Utah . It was replaced by a fill causeway in the 1960s, and is now being salvaged for its timber. Many wooden roller coasters are built using designs similar to trestle bridges because such a structure can be strong and support a high track path while using a relatively small amount of material. Since loads are well distributed through large portions of the structure it

468-648: The Mississippi Sound , which resulted in a federal award of damages in 2011 and ongoing federal litigation over the management of the spillway. The 2019 opening began February 27, 2019, when river levels were predicted to rise to minor flood stage in New Orleans on March 19, 2019. The Army Corps of Engineers initially opened 38 of the 350 bays and increased this number to 206 bays when the flood crest arrived later in March. The Army Corps of Engineers closed

504-429: The 19th century, the former making up from 1 to 3 percent of the total length of the average railroad. In the 21st century, steel and sometimes concrete trestles are commonly used to bridge particularly deep valleys, while timber trestles remain common in certain areas. Many timber trestles were built in the 19th and early 20th centuries with the expectation that they would be temporary. Timber trestles were used to get

540-503: The Baptist Parish, Louisiana. The incident was primarily caused by a combination of heavy fog and drifting smoke from nearby marsh fires, a phenomenon known as superfog. The crash took place on the elevated section of I-55, which spans from Ponchatoula to Manchac over the swamplands below. During the crash, one vehicle fell into the water and partially sank, while over 100 motorists were left stranded until rescue services could reach

576-542: The Bonnet Carré to redirect excess flows away from the Mississippi, and other aspects such as channel improvement and river bank stabilization, for efficient navigation and protection of the levee system. It also involves reservoirs and pumping stations for flood control drainage. The following chart shows the years when the spillway was opened, number of days it remained open, peak number of bays opened, percent of maximum flow at peak, and peak flow rate. The spillway has

612-502: The Davis Pond Freshwater Diversions, especially concerning wetlands maintenance more than wetlands building, has led to studies for more fresh water diversion projects. Caernarvon and Davis Pond diversions have limits, because of laws governing their operation, aimed at limiting the flow of freshwater to minimize damage to oysters. The Bonnet Carré Spillway diversion would be built within the spillway, on

648-792: The Kansas City Southern Railroad. The trestles were completed in 1936, after construction of the Spillway. The trestles may be the longest wooden railroad trestles remaining in regular use in North America. A coal trestle is a rigid-frame trestle supporting train tracks above chutes, used to deliver fuel to boats or trains beneath it. At the top of the trestle, rolling stock (typically hopper cars ) open doors on their undersides or on their sides to discharge cargo. Coal trestles were also used to transfer coal from mining railroads to rail cars. They were prominent when coal

684-474: The Mississippi River and Tributaries Project (MR&T), providing flood protection for the alluvial valley between Cape Girardeau, Missouri . and the mouth of the river near Venice , Louisiana. Because of the wide expanse of the project and the complex problems involved, the plan contains an array of features. The MR&T Project provides for levees to contain flood flows, floodways such as

720-446: The Mississippi River during flooding seasons, long has been a major source of sand and clay that is used in construction projects throughout the area. But in the post- Katrina era, clay extracted from the spillway will be crucial to raising the levees in St. Charles Parish and east Jefferson Parish . The several openings of the spillway have had a significant effect on marine fisheries in

756-410: The area. The collision involved 168 vehicles, resulting in 8 fatalities and 63 injuries. The severe conditions and scale of the accident posed significant challenges for emergency responders. This article about a bridge in Louisiana is a stub . You can help Misplaced Pages by expanding it . Trestle bridge#Concrete trestles Timber and iron trestles (i.e. bridges) were extensively used in

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792-526: The developing railway network in the United Kingdom. These generally carried decking consisting of some form of trussed girder, as at Crumlin Viaduct, Belah and Meldon ; though two rare examples, at Dowery Dell (demolished in 1962), and Bennerley had lattice girder decks. The steel trestle at Martinez, California, shown below, is a modern structure with a long expected lifetime compared to

828-560: The east bank of the Mississippi, allowing up to 25,000 c.f.s. (i.e. ft /s) of fresh water and sediment diversion into Lake Pontchartrain and the Mississippi Sound . The diversion would slow or stop subsidence , reducing marsh loss by 10,500 acres in the next 50 years, providing fish and wildlife protection, as well as further storm surge protection. The diversion was authorized by the Water Resources Development Act of 1988 (WRDA 1988), and Congress (1990) split

864-447: The flood surcharge portion of the water from the Mississippi is divided between the main river and the diversion channel, with the surcharge bypassing the New Orleans metropolitan area, resulting in the Mississippi being lower (through that area) than it could have been and reducing the stress on the area's levees that line the river. Confined by guide levees, the floodway stretches nearly six miles (9.7 km) to Lake Pontchartrain, with

900-693: The gravesites was a mystery until May 1975, when the US Army Corps of Engineers excavated a ditch in the spillway. During that process, a tombstone and casket were discovered. In 1986, the corps ordered a historical study of the spillway and discovered a second cemetery. The two cemeteries were placed on the National Register of Historic Places in 1987. The artifacts discovered during the 1986 study included coffin furniture, coffins, grave markers, cultural remains, and human remains. The Kenner and Kugler Cemeteries Archeological District consists of

936-578: The many deep valleys in Cornwall on the spinal rail route through the county. These were all replaced by masonry viaducts. Few timber trestles survived into the 20th century. Two that did, and which are still in daily use, cross the Afon Mawddach on the coast of Wales only a few miles apart, at Barmouth and Penmaenpool . The former, built in 1867, carries trains on the heavy rail Cambrian Coast Line travelling from England via Shrewsbury to

972-420: The railroad to its destination. Once the railroad was running, it was used to transport the material to replace trestles with more permanent works, transporting and dumping fill around some trestles and transporting stone or steel to replace others with more permanent bridges. In the later 20th century, tools such as the earthmover made it cheaper to construct a high fill directly instead of first constructing

1008-589: The rolling Camas Prairie and in the major grade, Lapwai Canyon. The 1,490-foot (450 m) viaduct across Lawyers Canyon was the exception, constructed of steel and 287 feet (87 m) in height. The floodway of the Bonnet Carré Spillway in St. Charles Parish, Louisiana, is crossed by three wooden trestles each over 1.5 miles (2.4 km) in length. The trestles are owned by the Canadian National Railway (two trestles) and

1044-399: The spillway on April 11, 2019, only to reopen it again on May 10, 2019. This marks the first time in the spillway's history that it was opened twice in one year. In April 2020 the Spillway was again opened from April 3, 2020, until May 1, 2020, a total of 29 days. The Bonnet Carré Spillway consists of two basic components: a control structure along the east bank of the Mississippi River and

1080-496: The spillway, the clay extraction pits were filled with water and stocked with bluegill , largemouth bass , and other fish . The floodgate inlet is offset into the Mississippi River bank, at a location that had seen natural flooding for at least two centuries. The concrete structure has been designed to reduce settling into the riverbank. The opening and closing of the spillway is done by lifting out up to 7000 wooden ' needles ' (8" x 12" wooden beams) arranged in 350 linear bays. This

1116-600: The two cemeteries. Additional research on the cemeteries was done in 2002–2005 and archaeological investigations in 2008–2009. The cemeteries, named the Kenner Cemetery and the Kugler Cemetery, are black burial plots which appear to date from the early 1800s and were in use until 1929. Several African-American US Army Civil War veterans were moved from the spillway cemeteries to Chalmette National Cemetery in 1930. The total number of burials in either cemetery

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1152-409: The various small towns on Cardigan Bay . It also carries a toll-path for pedestrians. Road traffic at this location has to travel many miles around the estuary to cross at either (for light traffic) the second trestle bridge, at Penmaenpool, which is a toll bridge; or (for heavy traffic) at Dolgellau even further up the estuary. Trestles in cast- or wrought-iron were used during the 19th century on

1188-476: The water to enter Lake Pontchartrain and surrounding urban areas. The river levee was not restored until 1883. The spillway was built in response to the Great Mississippi Flood of 1927 that inundated much of the Mississippi River basin. It was first opened during the flood of 1937 . In 2007, extraction operations began on a 42-acre (170,000 m ) square section of spillway property. The 7,600-acre (31 km ) spillway, designed to divert rising water out of

1224-474: Was an important fuel for rail locomotion and steamships , before they were replaced with mechanical coal loaders during the 20th century. Coal trestles were used in the Great Lakes ports of Buffalo (on Lake Erie ), Sodus Point and Oswego, New York (both on Lake Ontario ). In the United Kingdom, timber trestles were relatively short-lived as a structural type, one of their major uses being to cross

1260-479: Was recovered from the site. The Kugler Cemetery, located on the former Hermitage Plantation, was reported to contain iron crosses and a metal fence. One such iron cross and remnants of what could have been the fence were recovered during the 1986 archaeological investigations. At present, the cemetery sites have been demarcated by young live oak trees. The success of the Caernarvon Freshwater and

1296-647: Was the Atlantic Coast Line's Salkehatchie River trestle. Bonnet Carr%C3%A9 Spillway The Bonnet Carré Spillway / ˈ b ɒ n iː ˈ k ɛr iː / is a flood control operation in the Lower Mississippi Valley . Located in St. Charles Parish, Louisiana , about 12 miles (19 km) west of New Orleans , it allows floodwaters from the Mississippi River to flow into Lake Pontchartrain and thence into

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