 Micklewood Bridge as illustrated by Charles Drewry, 1832 | |
| Ancestor | Simple suspension bridge |
|---|---|
| Carries | Pedestrians, livestock |
| Span range | short |
| Movable | No |
| Design effort | low |
| Falsework required | No |
An underspanned suspension bridge (also upper deck suspension bridge [1] ) is a rare type of suspension bridge that was developed in the early 19th century.
It differs from its ancestor, the simple suspension bridge, in that the deck is raised on posts above the main cables. The raised deck is less stable than a deck laid on or hung below the cables, and very few underspanned suspension bridges have been built. Examples include Guillaume Henri Dufour's Pont des Bergues (1834); [2] and James Smith’s Micklewood Bridge. [3] Similar bridges were proposed by Robert Stevenson in 1820 for a bridge over the River Almond between Edinburgh and Queensferry, and by a Mr. Armstrong for a bridge at Clifton. [3] Part of the roadway on the land side of the piers of the Hammersmith Bridge was constructed in this manner. In the late 19th century and into the 20th century a few bridges of this type were constructed. [1]
The Micklewood Bridge, constructed at Doune in Scotland, was the very first of this type. [ citation needed ] It had a span of 103 feet (31 m), and the main cables were chains, making this an instance of a chain bridge. The deck was stiff and relatively stable, owing to heavy cross-braces. [3]
The only remaining underspanned suspension bridge in the United States is the Kellams Bridge crossing the upper Delaware River between New York and Pennsylvania. It is named for its builder.
A suspension bridge is a type of bridge in which the deck is hung below suspension cables on vertical suspenders. The first modern examples of this type of bridge were built in the early 1800s. Simple suspension bridges, which lack vertical suspenders, have a long history in many mountainous parts of the world.
A cable-stayed bridge has one or more towers, from which cables support 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 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.
The George Washington Bridge is a double-decked suspension bridge spanning the Hudson River, connecting Fort Lee in Bergen County, New Jersey, with Upper Manhattan in New York City. It is named after George Washington, the first president of the United States. The George Washington Bridge is the world's busiest motor vehicle bridge, carrying a traffic volume of over 104 million vehicles in 2019, and is the world's only suspension bridge with 14 vehicular lanes as of 2012. It is owned by the Port Authority of New York and New Jersey, a bi-state government agency that operates infrastructure in the Port of New York and New Jersey. The George Washington Bridge is also informally known as the GW Bridge, the GWB, the GW, or the George, and was known as the Fort Lee Bridge or Hudson River Bridge during construction. The George Washington Bridge measures 4,760 feet (1,450 m) long and has a main span of 3,500 feet (1,100 m). It was the longest main bridge span in the world from its 1931 opening until the Golden Gate Bridge in San Francisco opened in 1937.
An arch bridge is a bridge with abutments at each end shaped as a curved arch. Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side. A viaduct may be made from a series of arches, although other more economical structures are typically used today.
The John A. Roebling Suspension Bridge is a suspension bridge that spans the Ohio River between Cincinnati, Ohio, and Covington, Kentucky. When opened on December 1, 1866, it was the longest suspension bridge in the world at 1,057 feet (322 m) main span, which was later overtaken by John A. Roebling's most famous design of the 1883 Brooklyn Bridge at 1,595.5 feet (486.3 m). Pedestrians use the bridge to get between the hotels, bars, restaurants, and parking lots in Northern Kentucky. The bar and restaurant district at the foot of the bridge on the Kentucky side is known as Roebling Point.
Guillaume Henri Dufour was a Swiss military officer, structural engineer and topographer. He served under Napoleon I and held the Swiss office of General four times in his career, firstly in 1847 when he led the Swiss Confederation forces to victory against the Sonderbund. In 1864 Dufour presided over the First Geneva Convention which established the International Red Cross. He was founder and president of the Swiss Federal Office of Topography.
A self-anchored suspension bridge is a suspension bridge type in which the main cables attach to the ends of the deck, rather than directly to the ground or via large anchorages. The design is well-suited for construction atop elevated piers, or in areas of unstable soils where anchorages would be difficult to construct.
A simple suspension bridge is a primitive type of bridge in which the deck of the bridge lies on two parallel load-bearing cables that are anchored at either end. They have no towers or piers. The cables follow a shallow downward catenary arc which moves in response to dynamic loads on the bridge deck.
The eastern span replacement of the San Francisco–Oakland Bay Bridge was a construction project to replace a seismically unsound portion of the Bay Bridge with a new self-anchored suspension bridge (SAS) and a pair of viaducts. The bridge is in the U.S. state of California and crosses the San Francisco Bay between Yerba Buena Island and Oakland. The span replacement took place between 2002 and 2013, and is the most expensive public works project in California history, with a final price tag of $6.5 billion, a 2,500% cost overrun from the original estimate of $250 million. Originally scheduled to open in 2007, several problems delayed the opening until September 2, 2013. With a width of 258.33 ft (78.74 m), comprising 10 general-purpose lanes, it is the world's widest bridge according to Guinness World Records.
The Three Sisters are three similar self-anchored suspension bridges spanning the Allegheny River in downtown Pittsburgh, Pennsylvania at 6th, 7th, and 9th streets, generally running north/south. The bridges have been given formal names to honor important Pittsburgh residents:
The Niagara Falls Suspension Bridge stood from 1855 to 1897 across the Niagara River and was the world's first working railway suspension bridge. It spanned 825 feet (251 m) and stood 2.5 miles (4.0 km) downstream of Niagara Falls, where it connected Niagara Falls, Ontario to Niagara Falls, New York. Trains used the upper of its two decks, while pedestrians and carriages used the lower. The bridge was the idea of Canadian politicians, and it was built by an American company and a Canadian company. It was most commonly called the Suspension Bridge, although other names included Niagara Railway Suspension Bridge, Niagara Suspension Bridge, and its official American name of the International Suspension Bridge.
A suspension bridge supports its structural load with cables, ropes, or chains anchored at each end. Cables on the earliest suspension bridges were anchored in the ground; some modern suspension bridges anchor the cables to the ends of the bridge itself. Earliest suspension bridges had no towers or piers but the majority of larger modern suspension bridges have them. All of the 14 longest bridges in the world are suspension bridges.
Hampden Bridge is a heritage-listed single-span suspension bridge that carries Moss Vale Road (B73) across the Kangaroo River, in Kangaroo Valley, in the City of Shoalhaven local government area of New South Wales, Australia. The bridge was designed by Ernest de Burgh and built by Loveridge and Hudson. The property is owned by Transport for NSW. It was added to the New South Wales State Heritage Register on 2 August 2019.
Angers Bridge, also called the Basse-Chaîne Bridge, was a suspension bridge over the Maine River in Angers, France. It was designed by Joseph Chaley and Bordillon, and built between 1836 and 1839. The bridge collapsed on 16 April 1850, while a battalion of French soldiers was marching across it, killing over 200 of them.
Joseph Chaley was a French civil engineer and a pioneer designer of suspension bridges in the 19th century. He was a medical officer in the army before becoming a bridge designer.
The Kellams Bridge, also known as the Little Equinunk Bridge and Kellams–Stalker Bridge, is an underspanned suspension bridge spanning the Delaware River between Stalker, Pennsylvania, and Hankins, New York.
Spider Bridge at Falls of Schuylkill was an iron-wire footbridge erected in 1816 over the Schuylkill River, north of Philadelphia, Pennsylvania. Though a modest and temporary structure, it is thought to have been the first wire-cable suspension bridge in the world.
The Wellington Suspension Bridge is a suspension bridge crossing the River Dee from Ferryhill to Craiglug in Aberdeen, north east Scotland. Designed by Captain Samuel Brown and the Aberdeen City Architect John Smith, it was opened to pedestrians in November 1830 and to traffic in May 1831. The chain bridge was closed in 1984 to vehicles and then pedestrians in 2002, but was restored in 2006/07 and pedestrian use was re-instated in 2008.
The Surtees Rail Bridge is a rail bridge on the Tees Valley Line over the River Tees in the Borough of Stockton-on-Tees. The bridge is south of Stockton-on-Tees town centre and just north of the adjacent Surtees Bridge which carries the A66 road. The bridge is built on the site of a series of Tees Bridges alternating between two adjacent crossing sites.
The Chain Bridge is a pedestrian chain bridge in Nuremberg, Germany. The bridge crosses the river Pegnitz just a few meters upriver of Fronveste and Schlayerturm, fortifications in the course of the medieval city wall guarding the river's exit from the town. It connects Maxplatz in Sebalder Altstadt with Untere Kreuzgasse in Lorenz, the quarter on the south side of the river.
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