They were constructed by civil engineering contractors around the coast of Britain. They were collected at Dungeness and Selsey, and towed by tugboats across the English Channel, further caisson were added in the autumn of 1944 to re-enforce the existing structure to cope with the harbour continuing in use longer than planned. Several Phoenix breakwaters are still in use in Britain, two are part of the harbour off Castletown at Portland Harbour and two can be dived in less than 10 metres of water off Pagham, there is a smaller Phoenix Caisson in Langstone Harbour. A wrecked Phoenix breakwater is to be seen, broken in two, in the Thames estuary off Shoeburyness in Essex and it broke while being towed from Harwich in June 1944. To avoid it causing a hazard to shipping in the Thames estuary and it is about a mile from the beach. It is not quite covered at high tide, but it is topped by a beacon to warn shipping of its presence. Many unfamiliar with the mudflats have been trapped at the site by the tide, four Phoenix breakwaters were used in the Netherlands to plug a gap in the dyke at Ouwerkerk after the North Sea Flood of February 1st 1953.
They have now converted into a museum for the floods called the Watersnoodmuseum. One can walk through the four caissons, Mulberry harbour The Mulberry Harbour Units, Dorset
A boat lift, ship lift, or lift lock is a machine for transporting boats between water at two different elevations, and is an alternative to the canal lock and the canal inclined plane. The first known boat lift was a 2.5 ton tub boat lift on the Churprinz mining canal in Halsbrücke near Dresden and it lifted boats 7 metres without the use of caissons. The lift operated between 1789 and 1868, for a period of time after the opening of the Churprinz lift boat lifts were of an experimental nature with the engineer James Green reporting that 5 had been built between 1796 and 1830. He credited the invention to Dr James Anderson of Edinburgh, lifts on the tub boat section of the Grand Western Canal entered into operation in 1835 becoming the first non experimental boat lifts in Britain. 1904 the Peterborough Lift Lock designed by Richard Birdsall Rogers opened in Canada, the lift system is operated by gravity alone, with the upper bay of the two bay system loaded with an additional 30 cm of water as to give it greater weight.
Before the construction of the Three Gorges Dam Ship Lift, the highest boat lift, with a 73.15 metre height difference and European Class IV capacity, was the Strépy-Thieu boat lift in Belgium. The ship lift at the Three Gorges Dam, completed in January 2016, is 113 meters high, the boat lift at Longtan is reported to be even higher in total with a maximum vertical lift of 179m in two stages when completed. List of boat lifts Lock Balance lock Canal inclined plane – another technique for lifting boats, caisson lock, a submerged boat lift. Canal lifts and inclines of the world, the lift-locks on the Canal du Centre, at Houdeng and Strépy-Thieu, Belgium
A cofferdam is a temporary enclosure built within, or in pairs across, a body of water and constructed to allow the enclosed area to be pumped out. This pumping creates a dry environment for the major work to proceed. Enclosed coffers are commonly used for construction and repair of oil platforms, bridge piers and these cofferdams are usually welded steel structures, with components consisting of sheet piles and cross braces. Such structures are typically dismantled after the work is completed. These cofferdams are typically a conventional embankment dam of both earth- and rock-fill, but concrete or some sheet piling may be used. Typically, upon completion of the dam and associated structures, the downstream coffer is removed and the upstream coffer is flooded as the diversion is closed and the reservoir begins to fill. Dependent upon the geography of a dam site, in some applications, when complete, the cofferdam is removed and a similar one is created on the opposite side of the river for the construction of the dams other half.
The cofferdam is used on occasion in the shipbuilding and ship repair industry. An example of such an application is certain ship lengthening operations, in some cases a ship is actually cut in two while still in the water, and a new section of ship is floated in to lengthen the ship. Torch cutting of the hull is done inside a cofferdam attached directly to the hull of the ship, the cofferdam is replaced while the hull sections are welded together again. As expensive as this may be to accomplish, use of a drydock may be more expensive. A 100-ton open caisson that was lowered more than a mile to the sea floor in attempts to stop the flow of oil in the Deepwater Horizon oil spill has been called a cofferdam and it did not work, as methane hydrates froze in the upper levels preventing the containment. A cofferdam may refer to a space between two watertight bulkheads or decks within a ship. A cofferdam may be a space or a ballast space. Cofferdams are usually employed to ensure oil or other chemicals do not leak into machinery spaces, if two different cargoes that react dangerously with each other are carried on the same vessel, one or more cofferdams are usually required between the cargo spaces.
Portable cofferdams are inflatable cofferdams that can be reused, cofferdams of this type are stretched across the site, inflated with water from the prospected dry area. Once the area is dry, water still remaining from the dry area can be siphoned over to the wet area, the dictionary definition of cofferdam at Wiktionary Nautical Terms at phrontistery. info Portable Cofferdam at phrontistery. info
A dam is a barrier that impounds water or underground streams. Reservoirs created by not only suppress floods but provide water for activities such as irrigation, human consumption, industrial use, aquaculture. Hydropower is often used in conjunction with dams to generate electricity, a dam can be used to collect water or for storage of water which can be evenly distributed between locations. Dams generally serve the purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. The word dam can be traced back to Middle English, and before that, from Middle Dutch, the first known appearance of dam occurs in 1165. However, there is one village, that is mentioned in 1120. The word seems to be related to the Greek word taphos, so the word should be understood as dike from dug out earth. The names of more than 40 places from the Middle Dutch era such as Amsterdam and Rotterdam, early dam building took place in Mesopotamia and the Middle East.
Dams were used to control the level, for Mesopotamias weather affected the Tigris. The earliest known dam is the Jawa Dam in Jordan,100 kilometres northeast of the capital Amman and this gravity dam featured an originally 9-metre-high and 1 m-wide stone wall, supported by a 50 m-wide earth rampart. The structure is dated to 3000 BC, the Ancient Egyptian Sadd-el-Kafara Dam at Wadi Al-Garawi, located about 25 km south of Cairo, was 102 m long at its base and 87 m wide. The structure was built around 2800 or 2600 BC as a dam for flood control. During the Twelfth Dynasty in the 19th century BC, the Pharaohs Senosert III, Amenemhat III, two dams called Ha-Uar running east-west were built to retain water during the annual flood and release it to surrounding lands. The lake called Mer-wer or Lake Moeris covered 1,700 km2 and is today as Berkat Qaroun. One of the wonders of the ancient world was the Great Dam of Marib in Yemen. Repairs were carried out during various periods, most important around 750 BC and these extensive works were not actually finalized until 325 AD and allowed the irrigation of 25,000 acres.
By the mid-late 3rd century BC, an intricate water-management system within Dholavira in modern-day India was built, the system included 16 reservoirs and various channels for collecting water and storing it. Eflatun Pınar is a Hittite dam and spring temple near Konya and it is thought to be from the time of the Hittite empire between the 15th and 13th century BC
A synonym is a word or phrase that means exactly or nearly the same as another word or phrase in the same language. Words that are synonyms are said to be synonymous, and the state of being a synonym is called synonymy, the word comes from Ancient Greek sýn and ónoma. An example of synonyms are the words begin, commence, words can be synonymous when meant in certain senses, even if they are not synonymous in all of their senses. For example, if one talks about a time or an extended time, long. Some academics call the former type cognitive synonyms to distinguish them from the latter type, some lexicographers claim that no synonyms have exactly the same meaning because etymology, phonic qualities, ambiguous meanings, etc. make them unique. Different words that are similar in meaning usually differ for a reason, feline is more formal than cat and extended are only synonyms in one usage, synonyms are a source of euphemisms. In the figurative sense, two words are said to be synonymous if they have the same connotation. a widespread impression that.
Metonymy can sometimes be a form of synonymy, as when, for example, thus a metonym is a type of synonym, and the word metonym is a hyponym of the word synonym. The analysis of synonymy, polysemy and hypernymy is inherent to taxonomy and it has applications in pedagogy and machine learning, because they rely on word-sense disambiguation and schema. Synonyms can be any part of speech, as long as both words belong to the part of speech. Such like, he expired means the same as he died, in English, many synonyms emerged in the Middle Ages, after the Norman conquest of England. While Englands new ruling class spoke Norman French, the lower classes continued to speak Old English, today we have synonyms like the Norman-derived people and archer, and the Saxon-derived folk and bowman. For more examples, see the list of Germanic and Latinate equivalents in English, the purpose of a thesaurus is to offer the user a listing of similar or related words, these are often, but not always, synonyms. The word poecilonym is a synonym of the word synonym.
It is not entered in most major dictionaries and is a curiosity or piece of trivia for being a word because of its meta quality as a synonym of synonym. Antonyms are words with opposite or nearly opposite meanings, for example, hot ↔ cold, large ↔ small, thick ↔ thin, synonym ↔ antonym Hypernyms and hyponyms are words that refer to, respectively, a general category and a specific instance of that category. For example, vehicle is a hypernym of car, and car is a hyponym of vehicle, homophones are words that have the same pronunciation, but different meanings. For example and which are homophones in most accents, homographs are words that have the same spelling, but have different pronunciations
Bentonite is an absorbent aluminium phyllosilicate clay consisting mostly of montmorillonite. It was named by Wilbur C, knight in 1898 after the Cretaceous Benton Shale near Rock River, Wyoming. The different types of bentonite are each named after the dominant element, such as potassium, calcium. Experts debate a number of problems with the classification of bentonite clays. Bentonite usually forms from weathering of volcanic ash, most often in the presence of water, the term bentonite, as well as a similar clay called tonstein, has been used to describe clay beds of uncertain origin. For industrial purposes, two classes of bentonite exist and calcium bentonite. In stratigraphy and tephrochronology, completely devitrified ash-fall beds are commonly referred to as K-bentonites when the dominant clay species is illite, in addition to montmorillonite and illite another common clay species that is sometimes dominant is kaolinite. Kaolinite-dominated clays are referred to as tonsteins and are typically associated with coal.
Sodium bentonite expands when wet, absorbing as much as several times its dry mass in water, because of its excellent colloidal properties, it is often used in drilling mud for oil and gas wells and boreholes for geotechnical and environmental investigations. The property of swelling makes sodium bentonite useful as a sealant, since it provides a self-sealing and it is used to line the base of landfills, for example. Various surface modifications to sodium bentonite improve some rheological or sealing performance in applications, for example. Calcium bentonite is a useful adsorbent of ions in solution, as well as fats and it is the main active ingredient of fullers earth, probably one of the earliest industrial cleaning agents. Calcium bentonite may be converted to sodium bentonite to exhibit many of sodium bentonites properties by an ion exchange process, some properties, such as viscosity and fluid loss of suspensions, of sodium-beneficiated calcium bentonite may not be fully equivalent to those of natural sodium bentonite.
For example, residual calcium carbonates may result in performance of the bentonite in geosynthetic liners. Also known as potash bentonite or K-bentonite, potassium bentonite is a potassium-rich illitic clay formed from alteration of volcanic ash, the main uses of bentonite are for drilling mud, purifier, and as a groundwater barrier. As of around 1990, almost half of the US production of bentonite was used for drilling mud, bentonite is used in drilling fluids to lubricate and cool the cutting tools, to remove cuttings, and to help prevent blowouts. Much of bentonites usefulness in the drilling and geotechnical engineering industry comes from its rheological properties. Relatively small quantities of bentonite suspended in water form a viscous, most often, bentonite suspensions are thixotropic, although rare cases of rheopectic behavior have been reported
Bucket (machine part)
A bucket is a specialized container attached to a machine, as compared to a bucket adapted for manual use by a human being. It is a material handling component. The bucket has a volume as compared to other types of machine attachments like blades or shovels. The name bucket may have been coined from buckets used in water wheels, buckets in mechanical engineering can have a distinct quality from the traditional bucket whose purpose is to contain things. Larger versions of type of bucket equip bucket trucks to contain human beings, buckets in water-hauling systems in mines or, for instance. Buckets exist in a variety of sizes or shapes and they can be quite large like those equipping Hulett cranes, used to discharge ore out of cargo ships in harbours or very small such as those used by deep-sea exploration vehicles. The shape of the bucket can vary from the conical shape of an actual bucket to more scoop-like or spoon-like shapes akin to water turbines. The cross section can be round or square and this is the same shape of a domestic form, the one-piece-standing single element, but often with an augmented size.
In early developments of mining, a simple bucket allowed easy insertion of both miners and construction materials such as pit props, and extraction of miners and ore. Common terms used in parts of the world include, Kibble, Hoppit. Latterly they have been called sinking buckets, as they are now used when sinking new mine shafts before insertion of the cage. Concrete buckets help deliver concrete on a site of a building by the means of a tower crane. They have an opening to allow concrete to flow out of the bucket when in-place. They are placed at the end of an arm and have to be made from a material that provides isolation from electricity, like fiber glass. There may be a door on the side of the bucket, excavator buckets are made of solid steel and generally present teeth protruding from the cutting edge, to disrupt hard material and avoid wear-and-tear of the bucket. Subsets of the excavator bucket are, the bucket, trenching bucket, A ditching bucket is a wider bucket with no teeth, 5–6 feet used for excavating larger excavations. A trenching excavator bucket is normally 6 to 24 in wide, the design is used in bucket-wheel excavators.
The buckets in the wheel have to be made of material to withstand the resistance of the material it cuts through
The Brooklyn Bridge is a hybrid cable-stayed/suspension bridge in New York City and is one of the oldest bridges of either type in the United States. Completed in 1883, it connects the boroughs of Manhattan and Brooklyn by spanning the East River and it has a main span of 1,595.5 feet and was the first steel-wire suspension bridge constructed. Since its opening, it has become an icon of New York City and was designated a National Historic Landmark in 1964, although the Brooklyn Bridge is technically a suspension bridge, it uses a hybrid cable-stayed/suspension bridge design. The towers are built of limestone and Rosendale cement, the limestone was quarried at the Clark Quarry in Essex County, New York. The granite blocks were quarried and shaped on Vinalhaven Island, under a contract with the Bodwell Granite Company, the bridge was built with numerous passageways and compartments in its anchorages. New York City rented out the large vaults under the bridges Manhattan anchorage in order to fund the bridge, opened in 1876, the vaults were used to store wine, as they were always at 60 °F.
This was called the Blue Grotto because of a shrine to the Virgin Mary next to an opening at the entrance, construction of the bridge began in 1869. Roebling Suspension Bridge between Cincinnati and Covington, while conducting surveys for the bridge project, Roebling sustained a crush injury to his foot when a ferry pinned it against a piling. Compressed air was pumped into the caissons, and workers entered the space to dig the sediment, the whole weight of the bridge still sits upon a 15-foot thickness of southern yellow pine wood under the sediment. Many workers became sick with the bends in this work and this condition was unknown at the time, and was first called caisson disease by the project physician Andrew Smith. Washington Roebling suffered an injury as a result of decompression sickness shortly after ground was broken for the Brooklyn tower foundation on January 3,1870. Roeblings debilitating condition left him unable to supervise the construction firsthand. As Chief Engineer, Roebling supervised the project from his apartment with a view of the work and redesigning caissons.
He was aided by his wife Emily Warren Roebling who provided the critical link between her husband and the engineers on site. Under her husbands guidance, Emily studied higher mathematics, the calculations of catenary curves, the strengths of materials, bridge specifications, and she spent the next 11 years assisting Washington Roebling, helping to supervise the bridges construction. When iron probes underneath the caisson for the Manhattan tower found the bedrock to be deeper than expected. He deemed the aggregate overlying the bedrock 30 feet below it to be enough to support the tower base. The construction of the Brooklyn Bridge is detailed in the 1972 book The Great Bridge by David McCullough and Brooklyn Bridge, Burns drew heavily on McCulloughs book for the film and used him as narrator
Offshore geotechnical engineering
Offshore geotechnical engineering is a sub-field of geotechnical engineering. It is concerned with design, construction and decommissioning for human-made structures in the sea. Oil platforms, artificial islands and submarine pipelines are examples of such structures, the seabed has to be able to withstand the weight of these structures and the applied loads. Geohazards must be taken into account, there are more than 7,000 offshore platforms operating at a water depth up to and exceeding 2000 m. An offshore environment has several implications for geotechnical engineering and these include the following, Ground improvement and site investigation are expensive. Offshore structures are tall, often extending over 100 metres above their foundation, offshore structures typically have to contend with significant lateral loads. Cyclic loading can be a design issue. Offshore structures are exposed to a range of geohazards. The codes and technical standards are different from those used for onshore developments, design focuses on ultimate limit state as opposed to deformation.
Design modifications during construction are either unfeasible or very expensive, the design life of these structures often ranges between 25–50 years. The environmental and financial costs in case of failure can be higher, offshore structures are exposed to various environmental loads, waves, currents and, in cold oceans, sea ice and icebergs. Environmental loads act primarily in the direction, but have a vertical component. Some of these loads get transmitted to the foundation, wind and current regimes can be estimated from meteorological and oceanographic data, which are collectively referred to as metocean data. Earthquake-induced loading can occur – they proceed in the opposite direction, depending on location, other geohazards may be an issue. All of these phenomena may affect the integrity or the serviceability of the structure, marine sediments are composed of detrital material as well as remains of marine organisms, the latter making up calcareous soils. Total sediment thickness varies on a regional scale – it is higher near the coastline than it is away from it.
In places, the seabed can be devoid of sediment, due to strong bottom currents, the consolidation state of the soil is either normally consolidated, overconsolidated or underconsolidated. Wave forces induce motion of floating structures in all six degrees of freedom – they are a design criterion for offshore structures
Invasion of Normandy
The Western Allies of World War II launched the largest amphibious invasion in history when they assaulted Normandy, located on the northern coast of France, on 6 June 1944. The invaders were able to establish a beachhead as part of Operation Overlord after a successful D-Day, Allied land forces came from the United States, Britain and Free French forces. The Normandy invasion began with overnight parachute and glider landings, massive air attacks, the invasion began and during the evening the remaining elements of the airborne divisions landed. Land forces used on D-Day sailed from bases along the south coast of England, Allied forces rehearsed their D-Day roles for months before the invasion. On 28 April 1944, in south Devon on the English coast,749 U. S. soldiers and sailors were killed when German torpedo boats surprised one of these landing exercises, Exercise Tiger. In the months leading up to the invasion, the Allied forces conducted an operation, Operation Fortitude, aimed at misleading the Germans with respect to the date.
There were several leaks prior to or on D-Day, through the Cicero affair, the Germans obtained documents containing references to Overlord, but these documents lacked all detail. Double Cross agents, such as the Spaniard Juan Pujol, played an important role in convincing the German High Command that Normandy was at best a diversionary attack. After being told, Eisenhower reduced Miller to lieutenant colonel and sent him back to the U. S. where he retired, another such leak was General Charles de Gaulles radio message after D-Day. He, unlike all the leaders, stated that this invasion was the real invasion. This had the potential to ruin the Allied deceptions Fortitude North, in contrast, Gen. Eisenhower referred to the landings as the initial invasion. A full moon occurred on 6 June, Allied Expeditionary Force Supreme Commander Dwight D. Eisenhower had tentatively selected 5 June as the date for the assault. The weather was fine during most of May, but deteriorated in early June, the Allied troop convoys already at sea were forced to take shelter in bays and inlets on the south coast of Britain for the night.
It seemed possible that everything would have to be cancelled and the returned to their embarkation camps. The next full moon period would be nearly a month away, at a vital meeting on 5 June, Eisenhowers chief meteorologist forecast a brief improvement for 6 June. Commander of all forces for the invasion General Bernard Montgomery. Commander of the Allied Air Forces Air Chief Marshal Leigh Mallory was doubtful, on the strength of Staggs forecast, Eisenhower ordered the invasion to proceed. As a result, prevailing overcast skies limited Allied air support, some troops stood down and many senior officers were away for the weekend
A bridge is a structure built to span physical obstacles without closing the way underneath such as a body of water, valley, or road, for the purpose of providing passage over the obstacle. There are many different designs that each serve a particular purpose, the Oxford English Dictionary traces the origin of the word bridge to an Old English word brycg, of the same meaning. The word can be traced back to Proto-Indo-European *bʰrēw-. The word for the game of the same name has a different origin. The first bridges made by humans were probably spans of cut wooden logs or planks and eventually stones, using a simple support, some early Americans used trees or bamboo poles to cross small caverns or wells to get from one place to another. Dating to the Greek Bronze Age, it is one of the oldest arch bridges still in existence, several intact arched stone bridges from the Hellenistic era can be found in the Peloponnese. The greatest bridge builders of antiquity were the ancient Romans, the Romans built arch bridges and aqueducts that could stand in conditions that would damage or destroy earlier designs.
An example is the Alcántara Bridge, built over the river Tagus, the Romans used cement, which reduced the variation of strength found in natural stone. One type of cement, called pozzolana, consisted of water, sand and mortar bridges were built after the Roman era, as the technology for cement was lost. In India, the Arthashastra treatise by Kautilya mentions the construction of dams, a Mauryan bridge near Girnar was surveyed by James Princep. The bridge was swept away during a flood, and repaired by Puspagupta, the use of stronger bridges using plaited bamboo and iron chain was visible in India by about the 4th century. A number of bridges, both for military and commercial purposes, were constructed by the Mughal administration in India and this bridge is historically significant as it is the worlds oldest open-spandrel stone segmental arch bridge. European segmental arch bridges date back to at least the Alconétar Bridge, rope bridges, a simple type of suspension bridge, were used by the Inca civilization in the Andes mountains of South America, just prior to European colonization in the 16th century.
During the 18th century there were innovations in the design of timber bridges by Hans Ulrich Grubenmann, Johannes Grubenmann. The first book on bridge engineering was written by Hubert Gautier in 1716, a major breakthrough in bridge technology came with the erection of the Iron Bridge in Shropshire, England in 1779. It used cast iron for the first time as arches to cross the river Severn, with the Industrial Revolution in the 19th century, truss systems of wrought iron were developed for larger bridges, but iron does not have the tensile strength to support large loads. With the advent of steel, which has a tensile strength, much larger bridges were built. In 1927 welding pioneer Stefan Bryła designed the first welded bridge in the world
A crane is a type of machine, generally equipped with a hoist rope, wire ropes or chains, and sheaves, that can be used both to lift and lower materials and to move them horizontally. It is mainly used for lifting heavy things and transporting them to other places, the device uses one or more simple machines to create mechanical advantage and thus move loads beyond the normal capability of a human. The first known construction cranes were invented by the Ancient Greeks and were powered by men or beasts of burden and these cranes were used for the construction of tall buildings. Larger cranes were developed, employing the use of human treadwheels, in the High Middle Ages, harbour cranes were introduced to load and unload ships and assist with their construction – some were built into stone towers for extra strength and stability. The earliest cranes were constructed from wood, but cast iron, for many centuries, power was supplied by the physical exertion of men or animals, although hoists in watermills and windmills could be driven by the harnessed natural power.
The first mechanical power was provided by steam engines, the earliest steam crane being introduced in the 18th or 19th century, Cranes exist in an enormous variety of forms – each tailored to a specific use. Sizes range from the smallest jib cranes, used inside workshops, to the tallest tower cranes, mini-cranes are used for constructing high buildings, in order to facilitate constructions by reaching tight spaces. Finally, we can find larger floating cranes, generally used to oil rigs. Some lifting machines do not strictly fit the definition of a crane. The crane for lifting heavy loads was invented by the Ancient Greeks in the late 6th century BC, the archaeological record shows that no than c.515 BC distinctive cuttings for both lifting tongs and lewis irons begin to appear on stone blocks of Greek temples. The introduction of the winch and pulley hoist soon lead to a replacement of ramps as the main means of vertical motion. Also, the practice of erecting large monolithic columns was abandoned in favour of using several column drums.
The first unequivocal evidence for the existence of the compound pulley system appears in the Mechanical Problems attributed to Aristotle. The heyday of the crane in ancient times came during the Roman Empire, the Romans adopted the Greek crane and developed it further. We are relatively well informed about their techniques, thanks to rather lengthy accounts by the engineers Vitruvius. There are two surviving reliefs of Roman treadwheel cranes, with the Haterii tombstone from the late first century AD being particularly detailed, the simplest Roman crane, the trispastos, consisted of a single-beam jib, a winch, a rope, and a block containing three pulleys. Heavier crane types featured five pulleys or, in case of the largest one, the polyspastos, when worked by four men at both sides of the winch, could readily lift 3,000 kg. At the temple of Jupiter at Baalbek, for instance, the blocks weigh up to 60 tons each