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32-582: The Churchill Barriers are four causeways in the Orkney islands with a total length of 2.3 kilometres (1.4 mi). They link the Orkney Mainland in the north to the island of South Ronaldsay via Burray and the two smaller islands of Lamb Holm and Glimps Holm . The barriers were built between May 1940 and September 1944, primarily as naval defences to protect the anchorage at Scapa Flow , but since 12 May 1945 they serve as road links between

64-499: A computer and specialized software , including optimisation on haul cost and not haul distance (as haul cost is not proportional to haul distance). Earthwork software is generally a subset of CAD software, in which case it often an add-on to a more general CAD package such as AutoCAD . In that case, earthwork software is principally used to calculate cut and fill volumes which are then used for producing material and time estimates. Most products offer additional functionality such as

96-658: 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

128-704: 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. Earthworks (engineering) Earthworks are engineering works created through the processing of parts of the earth's surface involving quantities of soil or unformed rock . An incomplete list of possible temporary or permanent geotechnical shoring structures that may be designed and utilised as part of earthworks: Excavation may be classified by type of material: Excavation may be classified by

160-553: 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

192-527: 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

224-515: 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. A transport corridor that is carried instead on a series of arches, perhaps approaching a bridge, is a viaduct ;

256-477: 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

288-464: 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 ), from

320-480: 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,

352-508: Is usually used due to the amounts of material to be moved — up to millions of cubic metres. Earthwork construction was revolutionized by the development of the ( Fresno ) scraper and other earth-moving machines such as the loader , the dump truck , the grader , the bulldozer , the backhoe , and the dragline excavator . Engineers need to concern themselves with issues of geotechnical engineering (such as soil density and strength) and with quantity estimation to ensure that soil volumes in

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384-666: The Orkney Islands Council took control of the barriers from the Ministry of Defence . Since then, with increasingly erratic weather events and rising sea levels as a result of global climate change , the barriers have begun to deteriorate. Of the four barriers, only Barrier No. 2, from Lamb Holm to Glimps Holm, is at high risk for needing to be replaced, according to the Scottish Environment Protection Agency . Replacing even one of

416-426: The cuts match those of the fills , while minimizing the distance of movement. In the past, these calculations were done by hand using a slide rule and with methods such as Simpson's rule . Earthworks cost is a function of hauled amount x hauled distance. The goal of mass haul planning is to determine these amounts and the goal of mass haul optimization is to minimize either or both. Now they can be performed with

448-542: 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

480-668: The ability to takeoff terrain elevation from plans (using contour lines and spot heights ); produce shaded cut and fill maps; produce cross sections and visualize terrain in 3D. The means by which volumes are calculated in software can differ quite considerably leading to potentially different results with the same input data. Many software products use methods based on triangulated irregular networks (TINS) and triangular prism volume algorithms, however other calculation methods are in use based on rationalizing elevations into high density grids or cross-sections. A few programs are specialised in earthworks transport optimization and planning

512-404: The barriers were built from gabions enclosing 250,000 tonnes of broken rock, from quarries on Orkney. The gabions were dropped into place from overhead cableways into waters up to 18 metres (59 ft) deep. The bases were then covered with 66,000 locally cast concrete blocks in five-tonne and ten-tonne sizes. The five-tonne blocks were laid on the core, and the ten-tonne blocks were arranged on

544-646: The block ships. To prevent further attacks, First Lord of the Admiralty Winston Churchill ordered the construction of permanent barriers. Work began in May 1940 and the barriers were completed in September 1944 but were not officially opened until 12 May 1945, four days after Victory in Europe Day . The contract for building the barriers was awarded to Balfour Beatty , although part of

576-495: The causeways is extremely unpopular in Orkney due to their historical significance. The council was as of February 2021 exploring options that would preserve all of the causeways. Causeway 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

608-720: The cobbles together. However, some of the stones were left loose. In Scotland , the skirmish known as Clense the Calsey, or Cleanse the Causeway , took place in the High Street of Edinburgh in 1520. In the 18th century, Dahomey lacked an effective navy hence it built causeways for naval purposes starting in 1774. 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

640-458: 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

672-522: 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. Various causeways in

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704-710: The islands. The two southern barriers, Glimps Holm to Burray and Burray to South Ronaldsay, are Category A listed. On 14 October 1939, the Royal Navy battleship HMS Royal Oak was sunk at her moorings within the natural harbour of Scapa Flow , by the German submarine  U-47 under the command of Günther Prien . U-47 had entered Scapa Flow through Holm Sound, one of several eastern entrances to Scapa Flow. The eastern passages were protected by measures including sunken block ships, booms and anti-submarine nets, but U-47 entered at night at high tide by navigating between

736-451: The late Latin via calciata , a road stamped firm with the feet ( calcare , to tread)." 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

768-808: 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

800-634: The oldest engineered roads yet discovered is the Sweet Track in England . Built in 3807 or 3806 BC, 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

832-678: The purpose: Typical earthworks include road construction , railway beds , causeways , dams , levees , canals , and berms . Other common earthworks are land grading to reconfigure the topography of a site, or to stabilize slopes. In military engineering , earthworks are, more specifically, types of fortifications constructed from soil. Although soil is not very strong, it is cheap enough that huge quantities can be used, generating formidable structures. Examples of older earthwork fortifications include moats , sod walls , motte-and-bailey castles, and hill forts . Modern examples include trenches and berms . Heavy construction equipment

864-468: The remaining 700 at two camps on Burray. In 1943, those at Camp 60 built an ornate Italian Chapel , which still survives and has become a tourist attraction. Research by the University of York published in 2012 showed significant changes to the ecology of the area, and that behind the barriers an eutrophic environment dominated due to the loss of the natural throughflow of water. In October 2011,

896-484: The sides in a random pattern to act as wave-breaks. A project of this size required a substantial labour force, which peaked in 1943 at over 2,000. Much of the labour was provided by over 1,300 Italian prisoners of war who had been captured in the desert war in North Africa; they were transported to Orkney from early 1942 onwards. The prisoners were accommodated in three camps, 600 at Camp 60 on Little Holm and

928-466: The southernmost barrier (between Burray and South Ronaldsay) was sub-contracted to William Tawse & Co. The first Resident Superintending Civil Engineer was E K Adamson, succeeded in 1942 by G Gordon Nicol. Preparatory work on the site began in May 1940, while experiments on models for the design were undertaken at Whitworth Engineering Laboratories at the University of Manchester . The bases of

960-612: 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

992-435: 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

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1024-500: 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,

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