This article possibly contains original research .(November 2018) |
Ancestor | None. (See Ford (crossing)) |
---|---|
Related | None. (See Step-stone bridge) |
Descendant | None. (See Viaduct) |
Carries | Traffic, Rail, Cyclists, Pedestrians |
Material | Concrete, Masonry, Earth-fill |
Movable | No |
Design effort | medium |
Falsework required | No |
A causeway is a track, road or railway on the upper point of an embankment across "a low, or wet place, or piece of water". [1] It can be constructed of earth, masonry, wood, or concrete. One of the earliest known wooden causeways is the Sweet Track in the Somerset Levels, England, which dates from the Neolithic age. [2] Timber causeways may also be described as both boardwalks and bridges.
When first used, the word causeway appeared in a form such as "causey way", making clear its derivation from the earlier form "causey". This word seems to have come from the same source by two different routes. It derives ultimately, from the Latin for heel, calx, and most likely comes from the trampling technique to consolidate earthworks.
Originally, the construction of a causeway used earth that had been trodden upon to compact and harden it as much as possible, one layer at a time, often by slaves or flocks of sheep. Today, this work is done by machines. The same technique would have been used for road embankments, raised river banks, sea banks and fortification earthworks.
The second derivation route is simply the hard, trodden surface of a path. The name by this route came to be applied to any firmly surfaced road. It is now little-used except in dialect and in the names of roads which were originally notable for their solidly made surface. The 1911 Encyclopædia Britannica states: "causey, a mound or dam, which is derived, through the Norman-French caucie (cf. modern chaussée), [3] from the late Latin via calciata, a road stamped firm with the feet (calcare, to tread)." [4]
The word is comparable in both meanings with the French chaussée , from a form of which it reached English by way of Norman French. The French adjective chaussée carries the meaning of having been given a hardened surface and is used to mean either paved or shod. As a noun chaussée is used on the one hand for a metalled carriageway, and on the other for an embankment with or without a road.
Other languages have a noun with similar dual meaning. In Welsh, it is sarn. The Welsh is relevant here, as it also has a verb sarnu, meaning to trample. The trampling and ramming technique for consolidating earthworks was used in fortifications and there is a comparable, outmoded form of wall construction technique, used in such work and known as pisé, a word derived not from trampling but from ramming or tamping. The Welsh word cawsai translates directly to the English word 'causeway'; it is possible that, with Welsh being a lineal linguistic descendant of the original native British tongues, the English word derives from the Welsh.[ citation needed ]
A transport corridor that is carried instead on a series of arches, perhaps approaching a bridge, is a viaduct; a short stretch of viaduct is called an overpass. The distinction between the terms causeway and viaduct becomes blurred when flood-relief culverts are incorporated, though generally a causeway refers to a roadway supported mostly by earth or stone, while a bridge supports a roadway between piers (which may be embedded in embankments). Some low causeways across shore waters become inaccessible when covered at high tide.
The Aztec city-state of Tenochtitlan had causeways supporting roads and aqueducts. One of the oldest engineered roads yet discovered is the Sweet Track in England. Built in 3807 or 3806 BC, [5] the track was a walkway consisting mainly of planks of oak laid end-to-end, supported by crossed pegs of ash, oak, and lime, driven into the underlying peat.
In East Africa, the Husuni Kubwa (the "Great Fort"), situated outside the town of Kilwa, was an early 14th-century sultan's palace and emporium that contained causeways and platforms at the entrance of the Harbour made from blocks of reef and coral nearly a meter high. These acted as breakwaters, allowing mangroves to grow which is one of the ways the breakwater can be spotted from a distance. Some parts of the causeway are made from the bedrock, but usually the bedrock was used as a base. Coral stone was also used to build up the causeways, with sand and lime being used to cement the cobbles together. However, some of the stones were left loose. [6]
In Scotland, the skirmish known as Clense the Calsey, or Cleanse the Causeway, took place in the High Street of Edinburgh in 1520. [7]
In the 18th century, Dahomey lacked an effective navy hence it built causeways for naval purposes starting in 1774. [8]
The modern embankment may be constructed within a cofferdam : two parallel steel sheet pile or concrete retaining walls, anchored to each other with steel cables or rods. This construction may also serve as a dyke that keeps two bodies of water apart, such as bodies with a different water level on each side, or with salt water on one side and fresh water on the other. This may also be the primary purpose of a structure, the road providing a hardened crest for the dike, slowing erosion in the event of an overflow. It also provides access for maintenance as well perhaps, as a public service.
Notable causeways include those that connect Singapore and Malaysia (the Johor-Singapore Causeway), Bahrain and Saudi Arabia (25-km long King Fahd Causeway) and Venice to the mainland, all of which carry roadways and railways. In the Netherlands there are a number of prominent dikes which also double as causeways, including the Afsluitdijk, Brouwersdam, and Markerwaarddijk. In the Republic of Panama a causeway connects the islands of Perico, Flamenco, and Naos to Panama City on the mainland. It also serves as a breakwater for ships entering the Panama Canal.
Causeways are also common in Florida, where low bridges may connect several human-made islands, often with a much higher bridge (or part of a single bridge) in the middle so that taller boats may pass underneath safely. Causeways are most often used to connect the barrier islands with the mainland. In the case of the Courtney Campbell Causeway, however, the mainland (Hillsborough County) is connected by a causeway to a peninsula (Pinellas County). A well-known causeway is the NASA Causeway connecting the town of Titusville on the Florida mainland to the rocket-launching facility at the Kennedy Space Center on Merritt Island.
The Churchill Barriers in Orkney are some of the most notable sets of causeways in Europe. Constructed in waters up to 18 metres deep, the four barriers link five islands on the eastern side of the natural harbour at Scapa Flow. They were built during World War II as military defences for the harbour, on the orders of Winston Churchill.
The Estrada do Istmo connecting the islands of Taipa and Coloane in Macau was initially built as a causeway. The sea on both sides of the causeway then became shallower as a result of silting, and mangroves began to conquer the area. Later, land reclamation took place on both sides of the road and the area has subsequently been named Cotai and become home to several casino complexes.
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Various causeways in the world:
Unlike tunnels or bridges, causeways do not permit shipping through the strait which can cause problems. In some cases, causeways were built with "gates" or other facilities to permit shipping to pass through.
Causeways affect currents and may therefore be involved in beach erosion or changed deposition patterns; this effect has been a problem at the Hindenburgdamm in northern Germany. During hurricane seasons, the winds and rains of approaching tropical storms—as well as waves generated by the storm in the surrounding bodies of water—make traversing causeways problematic at best and impossibly dangerous during the fiercest parts of the storms. For this reason (and related reasons, such as the need to minimize traffic jams on both the roads approaching the causeway and the causeway itself), emergency evacuation of island residents is a high priority for local, regional, and even national authorities.
Causeways can separate populations of wildlife, putting further pressure on endangered species.
Causeways can cause a mineral imbalance between portions of a body of water. For example, a causeway built in the Great Salt Lake has caused the northern half of the lake to have much higher salinity, to the point that the two halves show a major color imbalance (as can be seen in the image at right). Furthermore, the difference in salinity has become so severe that native brine shrimp cannot survive in much of the waters, with the northern part being too salty and the southern part being insufficiently salty.
Holy Island is an island on the western side of the larger Isle of Anglesey, Wales, from which it is separated by the Cymyran Strait. It is called "Holy" because of the high concentration of standing stones, burial chambers and other religious sites on the small island. The alternative English name of the island is Holyhead Island. According to the 2011 UK Census, the population was 13,659, of whom 11,431 (84%) lived in the largest town, Holyhead.
The Johor Strait is an international strait in Southeast Asia, between Singapore and Peninsular Malaysia.
Biscayne Bay is a lagoon with characteristics of an estuary located on the Atlantic coast of South Florida. The northern end of the lagoon is surrounded by the densely developed heart of the Miami metropolitan area while the southern end is largely undeveloped with a large portion of the lagoon included in Biscayne National Park.
The King Fahd Causeway is a 25 km (15.5 mi) long series of bridges and causeways connecting Khobar, Saudi Arabia, and Al Jasra, Bahrain.
The Gulf of Bahrain is an inlet of the Persian Gulf on the east coast of Saudi Arabia, separated from the main body of water by the peninsula of Qatar. It surrounds the islands of Bahrain. The King Fahd Causeway crosses the western section of the Gulf of Bahrain, connecting Saudi Arabia to Bahrain.
Strelasund Crossing is the two links to the German island of Rügen (Rugia) over the Strelasund to the West Pomeranian mainland near Stralsund: the Rügen Bridge or Rugia Bridge and the Rugia Causeway.
The Courtney Campbell Causeway is the northernmost bridge across Old Tampa Bay, carrying State Road 60 between Clearwater, Florida in Pinellas County and Tampa, Florida in Hillsborough County.
The Mahim Causeway is a vital link road connecting Mumbai City district/South Mumbai with its Northern and Western Suburbs. The causeway links the neighbourhoods of Mahim to the south with Bandra to the north.
The Rickenbacker Causeway is a causeway that connects Miami, Florida to the barrier islands of Virginia Key and Key Biscayne across Biscayne Bay.
The Hindenburgdamm or Hindenburg Dam is an 11 km long causeway joining the North Frisian island of Sylt to mainland Schleswig-Holstein. Its coordinates are 54°53′N8°33′E. It was opened on 1 June 1927 and is exclusively a railway corridor. The companies that built the Hindenburgdamm, a job that took four years, were Philipp Holzmann AG of Frankfurt, working from the mainland, and Peter Fix Söhne of Duisburg working from Sylt. A train trip along the causeway takes about 10 minutes, and the time between the auto terminals at Niebüll on the mainland and Westerland on Sylt is about 30 minutes. The Hindenburgdamm is part of the railway line known as the Marschbahn, which is double-tracked along much of the route, although there as yet exists a single-tracked stretch. On the causeway is a signal box. The rail line is not electrified making the use of diesel locomotives necessary. Trains coming from origins further south like Hamburg change from an electric locomotive to a diesel locomotive at Itzehoe.
The NASA Causeway, is an east–west expressway in Brevard County, Florida, containing two causeways. The first causeway connects the Florida mainland to Merritt Island and later, over the private second causeway, connects Merritt Island to Cape Canaveral. As such, the NASA Causeway is the main route connecting points of interest in Titusville, Florida to the Kennedy Space Center on Merritt Island.
Serangoon Harbour is a harbour in Singapore located between the mainland island of Singapore and Pulau Ubin.
Klanxbüll is a municipality on the mainland in the northwest corner of Schleswig-Holstein, in Kreis Nordfriesland, Germany. The municipality belongs to the Amt Südtondern.
A fixed link or fixed crossing is a permanent, unbroken road or rail connection across water that uses some combination of bridges, tunnels, and causeways and does not involve intermittent connections such as drawbridges or ferries. A bridge–tunnel combination is commonly used for major fixed links.
The Matanzas Pass Bridge is a bridge located in Fort Myers Beach, Florida. It carries State Road 865 between the Florida mainland and Estero Island, which is a major tourist destination. The bridge is one of the island's two connections to the mainland. The other is the Bonita Beach Causeway on the south end of the island.
In March 2010, the Freeport of Monrovia became ISPS Compliant and moved from Security Level 2 to Security Level 1 in July 2010. The Freeport of Monrovia awarded an Operations Contract to APM Terminal to handle port operations, which includes container handling, cargo handling, and marine.
The Jewfish Creek Bridge is a beam bridge in the Florida Keys. Spanning both Jewfish Creek and Lake Surprise, it carries the Overseas Highway between the Florida Keys and the Florida mainland. The bridge is 65 feet (20 m) tall and opened in 2008, replacing a small drawbridge.
The Boca Grande Causeway is a causeway located in Charlotte County, Florida, connecting the community of Boca Grande on Gasparilla Island with the mainland near Placida. The 2.5-mile (4.0 km) causeway crosses Gasparilla Sound and consists of three bridges, and is the only vehicular access to the island.
King Fahd Passport Island, or simply Passport Island, is an artificial island partitioned between Bahrain and Saudi Arabia in the Gulf of Bahrain. Spread across 2.5 km (1.6 mi), it serves as the sole border crossing between the two countries and is used for connecting Saudi Arabia's Eastern Province to Bahrain's Northern Governorate through the King Fahd Causeway.
Gaoji Causeway is a 2,212-meter-long causeway in Xiamen, Fujian, China. It links Gaoqi in downtown Xiamen Island across the Xiamen Bay to Jimei District on the mainland. It used to serve as a road and rail link, as well as water piping into Xiamen Island. In order to improve the water quality around Xiamen Island, part of the causeway was blasted off and removed, replaced by bridge, and it would serve only as road link. Completed in 1955, along with Wuhan Yangtze River Bridge, the causeway is considered one of the major construction projects in the early years of the People's Republic of China. It remained Xiamen Island's sole link with the mainland until 1991. The Gaoji Causeway has a museum devoted to its construction and history founded in 2013.
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