An anchor is a device, normally made of metal, used to connect a vessel to the bed of a body of water to prevent the craft from drifting due to wind or current. The word derives from Latin ancora, which comes from the Greek ἄγκυρα. Anchors can either be temporary or permanent, permanent anchors are used in the creation of a mooring, and are rarely moved, a specialist service is normally needed to move or maintain them. Vessels carry one or more anchors, which may be of different designs. A sea anchor is a drogue, not in contact with the seabed, used to control a drifting vessel, anchors achieve holding power either by hooking into the seabed, or via sheer mass, or a combination of the two. Permanent moorings use large masses resting on the seabed, semi-permanent mooring anchors and large ships anchors derive a significant portion of their holding power from their mass, while hooking or embedding in the bottom. Modern anchors for smaller vessels have metal flukes which hook on to rocks on the bottom or bury themselves in soft seabed, the vessel is attached to the anchor by the rode, which is made of chain, rope, or a combination of these.
A10,1 scope gives the greatest holding power, Anchoring with sufficient scope and/or heavy chain rode brings the direction of strain close to parallel with the seabed. If necessary, motoring slowly around the location of the anchor helps dislodge it, anchors are sometimes fitted with a tripping line attached to the crown, by which they can be unhooked from rocks or coral. The term aweigh describes an anchor when it is hanging on the rope and is not resting on the bottom and this is linked to the term to weigh anchor, meaning to lift the anchor from the sea bed, allowing the ship or boat to move. An anchor is described as aweigh when it has broken out of the bottom and is being hauled up to be stowed. Aweigh should not be confused with under way, which describes a vessel which is not moored to a dock or anchored, the earliest anchors were probably rocks, and many rock anchors have been found dating from at least the Bronze Age. Pre-European Maori waka used one or more hollowed stones, tied with flax ropes, many modern moorings still rely on a large rock as the primary element of their design.
However, using pure mass to resist the forces of a storm only works well as a permanent mooring, the ancient Greeks used baskets of stones, large sacks filled with sand, and wooden logs filled with lead. According to Apollonius Rhodius and Stephen of Byzantium, anchors were formed of stone, such anchors held the vessel merely by their weight and by their friction along the bottom. Iron was afterwards introduced for the construction of anchors, and an improvement was made by forming them with teeth, or flukes, the Admiralty Pattern, A. P. or simply Admiralty, and known as Fisherman, is the anchor shape most familiar to non-sailors. It consists of a shank with a ring or shackle for attaching the rode. At the other end of the shank there are two arms, carrying the flukes, while the stock is mounted to the other end, when the anchor lands on the bottom, it will generally fall over with the arms parallel to the seabed
Masonry is the building of structures from individual units, which are often laid in and bound together by mortar, the term masonry can refer to the units themselves. The common materials of construction are brick, building stone such as marble, granite and limestone, cast stone, concrete block, glass block. Masonry is generally a durable form of construction. However, the used, the quality of the mortar and workmanship. A person who constructs masonry is called a mason or bricklayer, Masonry is commonly used for walls and buildings. Brick and concrete block are the most common types of masonry in use in industrialized nations, Concrete blocks, especially those with hollow cores, offer various possibilities in masonry construction. They generally provide great strength, and are best suited to structures with light transverse loading when the cores remain unfilled. Filling some or all of the cores with concrete or concrete with steel reinforcement offers much greater tensile, the use of material such as bricks and stones can increase the thermal mass of a building and can protect the building from fire.
Masonry walls are resistant to projectiles, such as debris from hurricanes or tornadoes. Extreme weather, under circumstances, can cause degradation of masonry due to expansion. Masonry tends to be heavy and must be built upon a foundation, such as reinforced concrete. Other than concrete, masonry construction does not lend well to mechanization. Masonry consists of components and has a low tolerance to oscillation as compared to other materials such as reinforced concrete, wood. Masonry has high compressive strength under vertical loads but has low tensile strength unless reinforced, the tensile strength of masonry walls can be increased by thickening the wall, or by building masonry piers at intervals. Where practical, steel reinforcements such as windposts can be added, a masonry veneer wall consists of masonry units, usually clay-based bricks, installed on one or both sides of a structurally independent wall usually constructed of wood or masonry. In this context the brick masonry is primarily decorative, not structural, the brick veneer is generally connected to the structural wall by brick ties.
There is typically an air gap between the veneer and the structural wall. Concrete blocks and cultured stones, and veneer adobe are sometimes used in a very similar veneer fashion
A slave is unable to withdraw unilaterally from such an arrangement and works without remuneration. Many scholars now use the chattel slavery to refer to this specific sense of legalised. In a broader sense, the word slavery may refer to any situation in which an individual is de facto forced to work against his or her will. Scholars use the generic terms such as unfree labour or forced labour. However – and especially under slavery in broader senses of the word – slaves may have some rights and/or protections, Slavery began to exist before written history, in many cultures. A person could become a slave from the time of their birth, while slavery was institutionally recognized by most societies, it has now been outlawed in all recognized countries, the last being Mauritania in 2007. Nevertheless, there are still more slaves today than at any point in history. The most common form of the trade is now commonly referred to as human trafficking. Chattel slavery is still practiced by the Islamic State of Iraq.
An older interpretation connected it to the Greek verb skyleúo to strip a slain enemy, there is a dispute among historians about whether terms such as unfree labourer or enslaved person, rather than slave, should be used when describing the victims of slavery. Chattel slavery, called traditional slavery, is so named because people are treated as the chattel of the owner and are bought, although it dominated many societies in the past, this form of slavery has been formally abolished and is very rare today. Even when it can be said to survive, it is not upheld by the system of any internationally recognized government. Indenture, otherwise known as bonded labour or debt bondage is a form of labour under which a person pledges himself or herself against a loan. The services required to repay the debt, and their duration, debt bondage can be passed on from generation to generation, with children required to pay off their parents debt. It is the most widespread form of slavery today, debt bondage is most prevalent in South Asia.
This may include institutions not commonly classified as slavery, such as serfdom, Human trafficking primarily involves women and children forced into prostitution. And is the fastest growing form of forced labour, with Thailand, India, Brazil, in 2007, Human Rights Watch estimated that 200,000 to 300,000 children served as soldiers in current conflicts. A forced marriage may be regarded as a form of slavery by one or more of the involved in the marriage
Retaining walls are structures designed to restrain soil to a slope that it would not naturally keep to. A retaining wall is a designed and constructed to resist the lateral pressure of soil. A basement wall is one kind of retaining wall. But the term refers to a cantilever retaining wall, which is a freestanding structure without lateral support at its top. These are cantilevered from a footing and rise above the grade on one side to retain a level grade on the opposite side. The walls must resist the pressures generated by loose soils or, in some cases. Every retaining wall supports a “wedge” of soil, the wedge is defined as the soil which extends beyond the failure plane of the soil type present at the wall site, and can be calculated once the soil friction angle is known. As the setback of the wall increases, the size of the wedge is reduced. This reduction lowers the pressure on the retaining wall, the most important consideration in proper design and installation of retaining walls is to recognize and counteract the tendency of the retained material to move downslope due to gravity.
Lateral earth pressures are zero at the top of the wall, earth pressures will push the wall forward or overturn it if not properly addressed. Also, any groundwater behind the wall that is not dissipated by a system causes hydrostatic pressure on the wall. The total pressure or thrust may be assumed to act at one-third from the lowest depth for lengthwise stretches of uniform height. Unless the wall is designed to retain water, It is important to have proper drainage behind the wall in order to limit the pressure to the design value. Drainage materials will reduce or eliminate the pressure and improve the stability of the material behind the wall. Drystone retaining walls are normally self-draining.5 against lateral sliding and overturning, gravity walls depend on their mass to resist pressure from behind and may have a batter setback to improve stability by leaning back toward the retained soil. For short landscaping walls, they are made from mortarless stone or segmental concrete units. Dry-stacked gravity walls are somewhat flexible and do not require a rigid footing, earlier in the 20th century, taller retaining walls were often gravity walls made from large masses of concrete or stone.
Cantilevered retaining walls are made from a stem of steel-reinforced
Rail transport is a means of conveyance of passengers and goods on wheeled vehicles running on rails, known as tracks. It is referred to as train transport. In contrast to road transport, where vehicles run on a flat surface. Tracks usually consist of rails, installed on ties and ballast, on which the rolling stock, usually fitted with metal wheels. Other variations are possible, such as slab track, where the rails are fastened to a concrete foundation resting on a prepared subsurface. Rolling stock in a transport system generally encounters lower frictional resistance than road vehicles, so passenger. The operation is carried out by a company, providing transport between train stations or freight customer facilities. Power is provided by locomotives which either draw electric power from a railway system or produce their own power. Most tracks are accompanied by a signalling system, Railways are a safe land transport system when compared to other forms of transport. The oldest, man-hauled railways date back to the 6th century BC, with Periander, one of the Seven Sages of Greece, Rail transport blossomed after the British development of the steam locomotive as a viable source of power in the 19th centuries.
With steam engines, one could construct mainline railways, which were a key component of the Industrial Revolution, railways reduced the costs of shipping, and allowed for fewer lost goods, compared with water transport, which faced occasional sinking of ships. The change from canals to railways allowed for markets in which prices varied very little from city to city. In the 1880s, electrified trains were introduced, and the first tramways, starting during the 1940s, the non-electrified railways in most countries had their steam locomotives replaced by diesel-electric locomotives, with the process being almost complete by 2000. During the 1960s, electrified high-speed railway systems were introduced in Japan, other forms of guided ground transport outside the traditional railway definitions, such as monorail or maglev, have been tried but have seen limited use. The history of the growth and restoration to use of transport can be divided up into several discrete periods defined by the principal means of motive power used.
The earliest evidence of a railway was a 6-kilometre Diolkos wagonway, trucks pushed by slaves ran in grooves in limestone, which provided the track element. The Diolkos operated for over 600 years, Railways began reappearing in Europe after the Dark Ages. The earliest known record of a railway in Europe from this period is a window in the Minster of Freiburg im Breisgau in Germany
Bahrain, officially the Kingdom of Bahrain, is a small Arab monarchy in the Persian Gulf. Bahrains population is 1,234,567, including 666,172 non-nationals and it is 780 km2 in size, making it the third smallest nation in Asia after the Maldives and Singapore. Bahrain is the site of the ancient Dilmun civilisation and it has been famed since antiquity for its pearl fisheries, which were considered the best in the world into the 19th century. Bahrain was one of the earliest areas to convert to Islam, following a period of Arab rule, Bahrain was occupied by the Portuguese in 1521, who in turn were expelled in 1602 by Shah Abbas I of the Safavid dynasty under the Persian Empire. In 1783, the Bani Utbah clan captured Bahrain from Nasr Al-Madhkur and it has since been ruled by the Al Khalifa royal family, in the late 1800s, following successive treaties with the British, Bahrain became a protectorate of the United Kingdom. Formerly a state, Bahrain was declared a Kingdom in 2002, in 2011, the country experienced protests inspired by the regional Arab Spring.
Bahrain had the first post-oil economy in the Persian Gulf, since the late 20th century, Bahrain has invested in the banking and tourism sectors. Many large financial institutions have a presence in Manama, the countrys capital, Bahrain has a high Human Development Index and was recognised by the World Bank as a high income economy. In Arabic, Bahrayn is the form of bahr, so al-Bahrayn means the two seas, although which two seas were originally intended remains in dispute. The term appears five times in the Quran, but does not refer to the modern island—originally known to the Arabs as Awal— but rather to all of Eastern Arabia. Today, Bahrains two seas are generally taken to be the bay east and west of the island. In addition to wells, there are areas of the sea north of Bahrain where fresh water bubbles up in the middle of the water as noted by visitors since antiquity. An alternate theory with regard to Bahrains toponymy is offered by the al-Ahsa region, another supposition by al-Jawahari suggests that the more formal name Bahri would have been misunderstood and so was opted against.
Until the late Middle Ages, Bahrain referred to the region of Eastern Arabia that included Southern Iraq, Kuwait, Al-Hasa, the region stretched from Basra in Iraq to the Strait of Hormuz in Oman. This was Iqlīm al-Bahrayns Bahrayn Province, the exact date at which the term Bahrain began to refer solely to the Awal archipelago is unknown. The entire coastal strip of Eastern Arabia was known as Bahrain for a millennium, the island and kingdom were commonly spelled Bahrein into the 1950s. Bahrain was home to the Dilmun civilization, an important Bronze Age trade centre linking Mesopotamia, Bahrain was ruled by the Assyrians and Babylonians. From the 6th to 3rd century BC, Bahrain was part of the Persian Empire ruled by the Achaemenian dynasty, by about 250 BC, Parthia brought the Persian Gulf under its control and extended its influence as far as Oman
Tilia is a genus of about 30 species of trees native throughout most of the temperate Northern Hemisphere. Commonly called lime trees in the British Isles, they are not related to the lime fruit, other names include linden, and basswood for the North American species. The genus occurs in Europe and eastern North America, but the greatest species diversity is found in Asia, Tilia species are mostly large, deciduous trees, reaching typically 20 to 40 metres tall, with oblique-cordate leaves 6 to 20 centimetres across. As with elms, the number of species is uncertain, as many if not most of the species will hybridise readily. Limes are hermaphroditic, having perfect flowers with male and female parts, pollinated by insects. The genus is called lime or linden in Britain and linden, lime. Within Germanic languages, English lithe, German lind lenient, yielding are from the same root, neither the name nor the tree is related to the citrus fruit called lime. Another common name used in North America is basswood, derived from bast, teil is an old name for the lime tree.
Latin tilia is cognate to Greek πτελέᾱ, elm tree, τιλίαι, black poplar, ultimately from a Proto-Indo-European word *ptel-ei̯ā with a meaning of broad, perhaps broad-leaved or similar. The Tilias sturdy trunk stands like a pillar and the divide and subdivide into numerous ramifications on which the twigs are fine. In summer, these are profusely clothed with large leaves and the result is a head of abundant foliage. The flowers of the European and American Tilia species are similar, except the American bears a petal-like scale among its stamens, all of the Tilia species may be propagated by cuttings and grafting, as well as by seed. They grow rapidly in rich soil, but are subject to the attack of many insects, Tilia is notoriously difficult to propagate from seed unless collected fresh in the fall. If allowed to dry, the seeds will go into a deep dormancy, cars left under the trees can quickly become coated with a film of the syrup thus dropped from higher up. The ant/aphid farming process does not appear to any serious damage to the trees.
In Europe, some linden trees reached considerable ages, a coppice of T. cordata in Westonbirt Arboretum in Gloucestershire is estimated to be 2,000 years old. In the courtyard of the Imperial Castle at Nuremberg is a Tilia which, by tradition recounted in 1900, was planted by the Empress Cunigunde, the Tilia of Neuenstadt am Kocher in Baden-Württemberg, was estimated at 1000 years old when it fell. The Alte Linde tree of Naters, Switzerland, is mentioned in a document in 1357, a plaque at its foot mentions that in 1155 a linden tree was already on this spot
The Hindenburgdamm or Hindenburg Dam is an 11 km-long causeway joining the North Frisian island of Sylt to mainland Schleswig-Holstein. 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, 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, every day, more than 100 trains pass over the causeway,50 of those ferrying cars. Each year, the railway ferries more than 450,000 vehicles over the causeway and this change in tides, it is believed, is part of what has led to the loss of a certain amount of land at Sylts southern end. The causeway lies in the specially protected Zone I of the Schleswig-Holsteinisches Wattenmeer National Park, walks on the tidal flats are not allowed here, although they are quite popular elsewhere.
After the Second War of Schleswig in 1864, when Prussia took over Schleswig from Denmark, the seaside bathing town of Westerland gradually grew in popularity. The west coast railway already ran from Altona by way of Husum, from here, the tracks were extended to the port at the Hoyerschleuse, whence paddlesteamers ran to Munkmarsch harbour on Sylt. The connection was at the tides mercy, and in winter, already being planned at that time was a rail causeway from the mainland to Nösse on Sylt. The horrendous cost of such a project kept it shelved for quite a while, westerlands growing popularity as a seaside resort led in 1910 to serious official planning for the rail causeway. World War I brought all planning to a stop, after the war, Germany was obliged to cede Tønder and the Hoyerschleuse to Denmark. Because of this situation, construction on the long planned causeway was finally begun by Philipp Holzmann in 1925. Early in the construction, a flood swept away what had already been built. After this experience, it was decided to realign the causeways route somewhat more towards the north, a trenchlike cofferdam was built to facilitate construction.
One thousand to 1,500 workers were employed on the project, in the two years that it took to build the causeway, more than 3 million cubic metres of sand and clay were moved, and 120,000 tonnes of stones used. It was opened on 1 June 1927, the auto-train terminal in Niebüll is connected to the Autobahnen in Schleswig-Holstein by Federal Highways B5 and B199. On 3 September 2009, there was an accident on the Hindenburgdamm when a squall blew a truck off a flatcar in one of the auto-trains. The driver was out of the truck and died at the accident scene
A levee, dyke, floodbank or stopbank is an elongated naturally occurring ridge or artificially constructed fill or wall, which regulates water levels. It is usually earthen and often parallel to the course of a river in its floodplain or along low-lying coastlines, the word levee, from the French word levée, is used in American English. It originated in New Orleans a few years after the founding in 1718 and was adopted by English speakers. The name derives from the trait of the ridges being raised higher than both the channel and the surrounding floodplains. The modern word dike or dyke most likely derives from the Dutch word dijk, the 126 kilometres long Westfriese Omringdijk was completed by 1250, and was formed by connecting existing older dikes. The Roman chronicler Tacitus even mentions that the rebellious Batavi pierced dikes to flood their land, the word dijk originally indicated both the trench and the bank. It is closely related to the English verb to dig, in Anglo-Saxon, the word dic already existed and was pronounced as dick in northern England and as ditch in the south.
Similar to Dutch, the English origins of the lie in digging a trench. This practice has meant that the name may be given to either the excavation or the bank, thus Offas Dyke is a combined structure and Car Dyke is a trench though it once had raised banks as well. In the midlands and north of England, and in the United States, a dike is what a ditch is in the south, a property boundary marker or small drainage channel. Where it carries a stream, it may be called a dike as in Rippingale Running Dike. The Weir Dike is a dike in Bourne North Fen, near Twenty and alongside the River Glen. In the Norfolk and Suffolk Broads, a dyke may be a ditch or a narrow artificial channel off a river or broad for access or mooring, some longer dykes being named. In parts of Britain, particularly Scotland, a dyke may be a field wall, Levees can be mainly found along the sea, where dunes are not strong enough, along rivers for protection against high-floods, along lakes or along polders. Furthermore, levees have been built for the purpose of empoldering, the latter can be a controlled inundation by the military or a measure to prevent inundation of a larger area surrounded by levees.
Levees have built as field boundaries and as military defences. More on this type of levee can be found in the article on dry-stone walls, Levees can be permanent earthworks or emergency constructions built hastily in a flood emergency. When such a bank is added on top of an existing levee it is known as a cradge
The Wadden Sea is an intertidal zone in the southeastern part of the North Sea. It lies between the coast of northwestern continental Europe and the range of Frisian Islands, forming a body of water with tidal flats. It is rich in biological diversity, in 2009, the Dutch and German parts of the Wadden Sea were inscribed on UNESCOs World Heritage List and the Danish part was added in June 2014. The Wadden Sea is one of the worlds seas whose coastline has been most modified by humans, via systems of dikes and causeways on the mainland, within the Netherlands it is bounded from the IJsselmeer by the Afsluitdijk. The islands in the Wadden Sea are called the Wadden Sea Islands or Frisian Islands and these are remnants of the once expansive and now submerged Doggerland. However, on the westernmost Dutch island, the Frisian language has not been spoken for centuries, the Danish Wadden Sea Islands have never been inhabited by Frisians. The outlying German island of Heligoland, although one of the Frisian Islands, is not situated in the Wadden Sea.
The German part of the Wadden Sea was the setting for the 1903 Erskine Childers novel The Riddle of the Sands, the word wad is Dutch for mud flat. The area is typified by extensive mud flats, deeper tidal trenches and the islands that are contained within this. The landscape has been formed for a part by storm tides in the 10th to 14th centuries. The present islands are a remnant of the coastal dunes. The islands are marked by dunes and wide, sandy beaches towards the North Sea, the impact of waves and currents, carrying away sediments, is slowly changing the layout of the islands. For example, the islands of Vlieland and Ameland have moved eastwards through the centuries, having lost land on one side, the Wadden Sea is famous for its rich flora and fauna, especially birds. Hundreds of thousands of waders and geese use the area as a stopover or wintering site. Some species that are extinct are still available here. Wadden Sea is an important habitat for two species of seals and grey seals, North Atlantic right whales and gray whales were once seen in the region, using the shallow, calm waters for either feeding and breeding before they were completely wiped out by shore-based whaling.
These two species are now thought to be extinct or remnant populations of which low-tens at best survive. One whale, possibly a right whale, was observed close to beaches on Texel in the West Frisian Islands and off Steenbanken, Schouwen-Duiveland in July 2005
The Somerset Levels are a coastal plain and wetland area of Somerset, South West England, running south from the Mendips to the Blackdown Hills. The Mendip Hills separate the Somerset Levels from the North Somerset Levels, the Somerset Levels consist of marine clay levels along the coast and inland peat-based moors, about 70 per cent is used as grassland and the rest is arable. Willow and teazel are grown commercially and peat is extracted, a Palaeolithic flint tool found in West Sedgemoor is the earliest indication of human presence in the area. The Levels were the location of the Glastonbury Lake Village as well as two Lake villages at Meare Lake, several settlements and hill forts were built on the natural islands of slightly raised land, including Brent Knoll and Glastonbury. In the Roman period sea salt was extracted and a string of settlements were set up along the Polden Hills. The discovery at Shapwick of 9,238 silver Roman coins, a number of Saxon charters document the incorporation of areas of moor in estates.
In 1685, the Battle of Sedgemoor was fought in the Bussex area of Westonzoyland at the conclusion of the Monmouth Rebellion, as a result of the wetland nature of the Levels, the area contains a rich biodiversity of national and international importance. It supports a vast variety of plant and bird species and is an important feeding ground for birds and includes 32 Sites of Special Scientific Interest, the area has been extensively studied for its biodiversity and heritage, and has a growing tourism industry. People have been draining the area since before the Domesday Book, in the Middle Ages, the monasteries of Glastonbury and Muchelney were responsible for much of the drainage. The artificial Huntspill River was constructed during the Second World War as a reservoir, the Sowy River between the River Parrett and Kings Sedgemoor Drain was completed in 1972, water levels are managed by the Levels internal drainage boards. Discussions have taken place concerning the possibility of obtaining World Heritage Site status for the Somerset Levels as a cultural landscape.
It was suggested that if this bid were successful it could improve flood control, but only if wetland fens were created again, the plans were abandoned in 2010. The Somerset Levels form a region that has been designated as a national character area – No.142 – by Natural England. The Levels are mainly flat areas of plains and a coastal sand and clay barrier. There are some slightly raised parts, called burtles, as well as higher ridges, the Levels are about 20 feet above mean sea level. The general elevation inland is 10 to 12 feet O. D. with peak tides of 25 to 26 feet O. D. recorded at Bridgwater, large areas of peat were laid down in the Brue Valley during the Quaternary period after the ice sheets melted. The area is prone to floods of fresh water and occasional salt water inundations. Another severe flood occurred in 1872–1873, when over 107 square miles were underwater from October to March, Glastonbury Tor is composed of Upper Lias Sand