title: Chevrolet Caprice

text: In 1999, GM again considered resurrecting the Caprice name in America for 2000, this time under this generation, and as a new Caprice 9C1 long before the appearance of the sixth-generation model (third-generation Holden Caprice) as the Caprice PPV, but it did return several years later as such.


title: Chevrolet Caprice

text: In November 2006, a completely redesigned Caprice lineup was launched, again based on the recently introduced Holden WM Statesman/Caprice. The new Caprice lineup includes the base LS, LTZ, SS and Royale, all sporting the new "L98" 6.0 L V8.


title: Chevrolet Caprice

text: The LS, LTZ, and Royale all share the front bumper as the Holden WM Statesman while the LS lacks the Statesman's trademark foglights which are seen on the LTZ and Royale; the SS gains the Caprice's front bumper and foglamps minus the parking sensors. The LS also gains the VE Commodore Omega's interior and trims, while the LTZ gains the trims from the VE Commodore V based on the Commodore Omega, and the Statesman's interior minus the headrests with the LCD screens and DVD player, while the Royale gains the Statesman's trims, and the Statesman's interior with the LCD screens in the headrests and DVD player from the Holden versions, the grille from the Daewoo Veritas, hood ornament similar to the one that the appears on the 4th and 5th generation models, and the SS gains the same trims as the WM Caprice, interior from the Caprice minus the headrests with the LCD screens and DVD player, color-coded version of the grille's trim, and the optional lip spoiler from the WM Caprice.


title: Chevrolet Caprice

text: The Caprice was updated for 2011 to include the features that Holden included the Holden Caprice. The Caprice lettering engraved on the chrome trim which was on the car from 2000 until 2010 on the trim was dropped & replaced by a Caprice nameplate badge which is below the chrome trim on the left end of the rear fascia on the trunk. The V6 engines were dropped in the LS & LTZ leaving the V8 as the standard engine while the LS got the trims that were previously on the LTZ from 2007-2010 as well as previously seen on the VE Commodore V based on the Omega Series I model, while the LTZ & Royale get the trims seen on the VE Commodore Calais V Series II and the 2010 and 2011 Chevrolet Omega Fittipaldi Edition and the SS now gains the trims that the WM Caprice V Series II has. The LS, LTZ, & Royale still retain the Statesman front bumper, while the SS still retains the Caprice/Caprice V front bumper. The Royale also gains a rear vision camera in the chrome trim on the trunk which is absent on the LS, LTZ, & SS like the Holden Caprice & Caprice V. For the 2013 model year for the Caprice SS the Impala badge on the trunk was dropped in favor of the traditional Chevrolet bowtie.


title: Chevrolet Caprice

text: The Caprice was updated again based on the Holden WN Caprice. The Caprice LS & LTZ still retain the front bumper as the WM Statesman while the Royale now gets the same front bumper as seen on the WM/WN Caprice and the Caprice SS and the trims that were previously on the 2011-2013 Caprice SS, the 2010-2013 WM Caprice V, and currently the WN Caprice LPG model, and the Holden Commodore (VF) Calais's interior just like the Holden models. The SS now gains the rear vision camera which was previously only available on the Caprice Royale while it is still not available on the Caprice LS or LTZ, the same interior updates the WN Caprice and Caprice Royale, and also delivered the same trims as on the WN Caprice V & while the LS, LTZ, and SS gain new trims.


title: Chevrolet Caprice

text: The Holden-sourced Chevrolet Caprice in the LS trim is used in Middle East police forces in the Saudi Arabia, United Arab Emirates such as the Abu Dhabi Police, Royal Oman Police, and Dubai Police Force. In 2012 after the Libyan Civil War ended the Abu Dhabi Police donated 100 of its Caprice LS police cars to Libya along with uniforms making it the only country in the continent of Africa to have the Holden sourced Caprices in service.


title: Chevrolet Caprice

text: The Caprice PPV was based on a previous Australian-built export to the Middle East, the Chevrolet Caprice LS (which was based on the Holden Caprice WM series I, sold only in the Australasian market). The front end and grille were the same as the 2007–2010 Caprice LS.


title: Chevrolet Caprice

text: While the 2009 onward Chevrolet Caprice was officially sold only to law enforcement agencies in the US, some vehicles evidently were been purchased by private individuals via dealers. These included demonstrator vehicles, excess unsold dealer inventory, and purchases for demonstration use by upfitters and related businesses.


title: Chevrolet Caprice

text: The Caprice PPV was imported from Australia as a captive import of the Holden Caprice (WM series), rather than the short-wheelbase Holden Commodore (VE), which was sold in a police pack in Australia. (However, these cars were both designed on GM's Zeta platform.


title: Chevrolet Caprice

text: Australian-built Chevrolet Caprices featured either the 6.0 L "L77" AFM V8, which was standard in 2011 and optional from 2012; or the standard 3.6 L "LLT" SIDI V6 engine, that became available nine months later. Both engines were E85 ethanol-capable.


title: Chevrolet Caprice

text: The Caprice police car had a generally positive reception, placing perfect scores in an assessment by The Los Angeles County Sheriff's Department, with the only criticism being directed at its over-cautious electronic stability control.


title: Chevrolet Caprice

text: The Caprice logo was engraved into the chrome trim on the trunk, there was a PPV logo on the right side of the rear fascia and a FlexFuel nameplate, which was on GM vehicles in North America from 2007 through 2009. The PPV had dual exhausts, a floor shifter in the console, a prisoner partition with rifle and shotgun mounts, lights and siren controls in the console, 18-inch steel wheels and center caps from the Impala 9C1, and a touch screen in place of the radio and HVAC controls. A prototype similar to the concept car in LAPD was shown publicly in Australia by Holden. Another prototype tested by the LAPD had the same front end, grille, steel wheels, and center caps as the production models, while the car was based on the Series I WM Caprice with its rear bumper, colored turn signal indicators lamps on the side of the car, chrome trim with Caprice engraved on it, & V8 badge from the 2007-2010 Caprice.


title: Chevrolet Caprice

text: Special features were added by Chevrolet for the Caprice Police Patrol Vehicle (PPV). The driver's seat had a special indentation made to accommodate a police officer's equipment belt. Special tuning, such as Performance Algorithm Liftfoot (PAL) calibration and a performance-tuned suspension was added for increased performance, for police needs.


title: Chevrolet Caprice

text: Previously, the future of Holden's North American export program had been the subject of contradictory announcements, as General Motors emerged from bankruptcy. On July 11, 2009, Bob Lutz declared the Australian-built, Holden Commodore-based Pontiac G8 "too good to waste" and indicated it would return in the form of a Chevrolet Caprice. Initially, it was unclear whether the revived Caprice marque, in North America, would be based on the short-wheelbase Commodore (like the Pontiac G8) or the longer Holden/Chevrolet Caprice variants already sold in Australasia and the Middle East. Several days later, Lutz retracted his comment, citing market conditions, while GM CEO Frederick Henderson confirmed that police applications were being studied.


title: Chevrolet Caprice

text: What also made the North America Caprice different from the preceding Caprice variants sold in Australasia and the Middle East was the lower end of the front bumper (based on the Holden Commodore Omega Series II front end), a honeycomb grille similar to the 2001-2011 Ford Crown Victoria Police Interceptor, and an interior from the Commodore Omega. (The latter was the common trim of the VE Commodore police packs sold in Australasia in 2007-2013.) An unmarked detective subvariant of the PPV used the same interior as the Middle East market variant Caprice LS, from 2007–2013.


title: Chevrolet Caprice

text: Standard equipment on the Caprice PPV included keyless entry, power windows and door locks, a 6.5-inch, full-color LCD audio system with auxiliary audio input and a single-disc CD player, a four-speaker front audio system with separate woofers and tweeters, full instrumentation with an integrated driver information center (DIC), air conditioning with dual-zone temperature controls for the driver and front passenger, dual front bucket seats with a power driver's seat adjuster, a cruise control, and front and rear cloth seating surfaces. Optional features included wiring for police lighting and sirens, an additional battery to power police-installed accessories, the disabling of the interior courtesy lamps and rear door window controls and door locks, eighteen-inch (18") plastic wheel covers, a vinyl rear bench seat, rubberized vinyl flooring and rear trunk mats, and a remote vehicle starter system.


title: Chevrolet Caprice

text: For 2014, the Caprice PPV received a new seven-inch, Chevrolet MyLink touchscreen infotainment system as standard equipment, which now included Bluetooth for hands-free calling and wireless stereo audio streaming via A2DP, Pandora Internet Radio capabilities, ad an integrated rearview backup camera display, among other new features. The single-disc CD player was deleted for the 2014 model year as well. The dashboard was restyled with a new steering wheel that integrated cruise (speed), audio system, and Bluetooth voice controls, a new instrument cluster with a larger monochromatic LCD driver information center (DIC) screen, and revised controls (the new dashboard in the Caprice PPV was similar to the civilian Chevrolet SS sedan that was released for the 2014 model year). The gear selector lever for the six-speed automatic transmission was relocated from the center console to the steering column, which freed up space in the center console for police-installed equipment, such as computers and radio equipment. In addition, the door panels were redesigned with more convenient control placement, and the front bucket seats were redesigned for greater officer comfort and support, with a new seat fabric for the cloth seats.


title: Chevrolet Caprice

text: In 2017, General Motors closed the Elizabeth, South Australia assembly plant where the Caprice PPV was produced, ending production of both the civilian Chevrolet SS and Caprice PPV. With the discontinuation of the 9C1 Chevrolet Impala Limited Police Interceptor after the 2016 model year, Chevrolet no longer offers a four-door sedan with a Police Package.


title: Chevrolet Caprice

text: From late 1975 to 1978 the Australian developed Statesman Caprice was marketed in South Africa as the "Chevrolet Caprice Classic". The V8-engined Caprice Classic received full equipment, with reading lights, air conditioning, and imported leather upholstery. It was very similar to the 5-liter Constantia, albeit fitted with a different grille, hubcaps, and a vinyl roof.


title: Archimedes' principle

text: Archimedes' principle (also spelled Archimedes's principle) states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially, is equal to the weight of the fluid that the body displaces. Archimedes' principle is a law of physics fundamental to fluid mechanics. It was formulated by Archimedes of Syracuse.


title: Archimedes' principle

text: Archimedes' principle allows the buoyancy of any floating object partially or fully immersed in a fluid to be calculated. The downward force on the object is simply its weight. The upward, or buoyant, force on the object is that stated by Archimedes' principle above. Thus, the net force on the object is the difference between the magnitudes of the buoyant force and its weight. If this net force is positive, the object rises; if negative, the object sinks; and if zero, the object is neutrally buoyant—that is, it remains in place without either rising or sinking. In simple words, Archimedes' principle states that, when a body is partially or completely immersed in a fluid, it experiences an apparent loss in weight that is equal to the weight of the fluid displaced by the immersed part of the body(s).


title: Archimedes' principle

text: Consider a cuboid immersed in a fluid, its top and bottom faces orthogonal to the direction of gravity (assumed constant across the cube's stretch). The fluid will exert a normal force on each face, but only the normal forces on top and bottom will contribute to buoyancy. The pressure difference between the bottom and the top face is directly proportional to the height (difference in depth of submersion). Multiplying the pressure difference by the area of a face gives a net force on the cuboid  —  the buoyancy  —  equaling in size the weight of the fluid displaced by the cuboid. By summing up sufficiently many arbitrarily small cuboids this reasoning may be extended to irregular shapes, and so, whatever the shape of the submerged body, the buoyant force is equal to the weight of the displaced fluid.


title: Archimedes' principle

text: The weight of the displaced fluid is directly proportional to the volume of the displaced fluid (if the surrounding fluid is of uniform density). The weight of the object in the fluid is reduced, because of the force acting on it, which is called upthrust. In simple terms, the principle states that the buoyant force (F) on an object is equal to the weight of the fluid displaced by the object, or the density (ρ) of the fluid multiplied by the submerged volume (V) times the gravity (g)


title: Archimedes' principle

text: where formula_3 denotes the buoyant force applied onto the submerged object, formula_4 denotes the density of the fluid, formula_5 represents the volume of the displaced fluid and formula_6 is the acceleration due to gravity.


title: Archimedes' principle

text: Thus, among completely submerged objects with equal masses, objects with greater volume have greater buoyancy.


title: Archimedes' principle

text: Suppose a rock's weight is measured as 10 newtons when suspended by a string in a vacuum with gravity acting on it. Suppose that, when the rock is lowered into the water, it displaces water of weight 3 newtons. The force it then exerts on the string from which it hangs would be 10 newtons minus the 3 newtons of buoyant force: 10 − 3 = 7 newtons. Buoyancy reduces the apparent weight of objects that have sunk completely to the sea-floor. It is generally easier to lift an object through the water than it is to pull it out of the water.


title: Archimedes' principle

text: yields the formula below. The density of the immersed object relative to the density of the fluid can easily be calculated without measuring any volume is


title: Archimedes' principle

text: Example: A helium balloon in a moving car. When increasing speed or driving in a curve, the air moves in the opposite direction to the car's acceleration. However, due to buoyancy, the balloon is pushed "out of the way" by the air and will drift in the same direction as the car's acceleration.


title: Archimedes' principle

text: When an object is immersed in a liquid, the liquid exerts an upward force, which is known as the buoyant force, that is proportional to the weight of the displaced liquid. The sum force acting on the object, then, is equal to the difference between the weight of the object ('down' force) and the weight of displaced liquid ('up' force). Equilibrium, or neutral buoyancy, is achieved when these two weights (and thus forces) are equal.


title: Archimedes' principle

text: where f is the force density exerted by some outer field on the fluid, and "σ" is the Cauchy stress tensor. In this case the stress tensor is proportional to the identity tensor:


title: Archimedes' principle

text: Assuming the outer force field is conservative, that is it can be written as the negative gradient of some scalar valued function:


title: Archimedes' principle

text: Therefore, the shape of the open surface of a fluid equals the equipotential plane of the applied outer conservative force field. Let the "z"-axis point downward. In this case the field is gravity, so Φ = −"ρgz" where "g" is the gravitational acceleration, "ρ" is the mass density of the fluid. Taking the pressure as zero at the surface, where "z" is zero, the constant will be zero, so the pressure inside the fluid, when it is subject to gravity, is


title: Archimedes' principle

text: So pressure increases with depth below the surface of a liquid, as "z" denotes the distance from the surface of the liquid into it. Any object with a non-zero vertical depth will have different pressures on its top and bottom, with the pressure on the bottom being greater. This difference in pressure causes the upward buoyancy force.


title: Archimedes' principle

text: The buoyancy force exerted on a body can now be calculated easily, since the internal pressure of the fluid is known. The force exerted on the body can be calculated by integrating the stress tensor over the surface of the body which is in contact with the fluid:


title: Archimedes' principle

text: where "V" is the measure of the volume in contact with the fluid, that is the volume of the submerged part of the body, since the fluid doesn't exert force on the part of the body which is outside of it.


title: Archimedes' principle

text: The magnitude of buoyancy force may be appreciated a bit more from the following argument. Consider any object of arbitrary shape and volume "V" surrounded by a liquid. The force the liquid exerts on an object within the liquid is equal to the weight of the liquid with a volume equal to that of the object. This force is applied in a direction opposite to gravitational force, that is of magnitude:


title: Archimedes' principle

text: where "ρ" is the density of the fluid, "V" is the volume of the displaced body of liquid, and "g" is the gravitational acceleration at the location in question.


title: Archimedes' principle

text: If this volume of liquid is replaced by a solid body of exactly the same shape, the force the liquid exerts on it must be exactly the same as above. In other words, the "buoyancy force" on a submerged body is directed in the opposite direction to gravity and is equal in magnitude to


title: Archimedes' principle

text: The net force on the object must be zero if it is to be a situation of fluid statics such that Archimedes principle is applicable, and is thus the sum of the buoyancy force and the object's weight


title: Archimedes' principle

text: If the buoyancy of an (unrestrained and unpowered) object exceeds its weight, it tends to rise. An object whose weight exceeds its buoyancy tends to sink. Calculation of the upwards force on a submerged object during its accelerating period cannot be done by the Archimedes principle alone; it is necessary to consider dynamics of an object involving buoyancy. Once it fully sinks to the floor of the fluid or rises to the surface and settles, Archimedes principle can be applied alone. For a floating object, only the submerged volume displaces water. For a sunken object, the entire volume displaces water, and there will be an additional force of reaction from the solid floor.


title: Archimedes' principle

text: In order for Archimedes' principle to be used alone, the object in question must be in equilibrium (the sum of the forces on the object must be zero), therefore;


title: Archimedes' principle

text: showing that the depth to which a floating object will sink, and the volume of fluid it will displace, is independent of the gravitational field regardless of geographic location.


title: Archimedes' principle

text: It can be the case that forces other than just buoyancy and gravity come into play. This is the case if the object is restrained or if the object sinks to the solid floor. An object which tends to float requires a tension restraint force T in order to remain fully submerged. An object which tends to sink will eventually have a normal force of constraint N exerted upon it by the solid floor. The constraint force can be tension in a spring scale measuring its weight in the fluid, and is how apparent weight is defined.


title: Archimedes' principle

text: Another possible formula for calculating buoyancy of an object is by finding the apparent weight of that particular object in the air (calculated in Newtons), and apparent weight of that object in the water (in Newtons). To find the force of buoyancy acting on the object when in air, using this particular information, this formula applies:


title: Archimedes' principle

text: Air's density is very small compared to most solids and liquids. For this reason, the weight of an object in air is approximately the same as its true weight in a vacuum. The buoyancy of air is neglected for most objects during a measurement in air because the error is usually insignificant (typically less than 0.1% except for objects of very low average density such as a balloon or light foam).


title: Archimedes' principle

text: A simplified explanation for the integration of the pressure over the contact area may be stated as follows:


title: Archimedes' principle

text: The sides are identical in area, and have the same depth distribution, therefore they also have the same pressure distribution, and consequently the same total force resulting from hydrostatic pressure, exerted perpendicular to the plane of the surface of each side.


title: Archimedes' principle

text: There are two pairs of opposing sides, therefore the resultant horizontal forces balance in both orthogonal directions, and the resultant force is zero.


title: Archimedes' principle

text: The upward force on the cube is the pressure on the bottom surface integrated over its area. The surface is at constant depth, so the pressure is constant. Therefore, the integral of the pressure over the area of the horizontal bottom surface of the cube is the hydrostatic pressure at that depth multiplied by the area of the bottom surface.


title: Archimedes' principle

text: Similarly, the downward force on the cube is the pressure on the top surface integrated over its area. The surface is at constant depth, so the pressure is constant. Therefore, the integral of the pressure over the area of the horizontal top surface of the cube is the hydrostatic pressure at that depth multiplied by the area of the top surface.


title: Archimedes' principle

text: As this is a cube, the top and bottom surfaces are identical in shape and area, and the pressure difference between the top and bottom of the cube is directly proportional to the depth difference, and the resultant force difference is exactly equal to the weight of the fluid that would occupy the volume of the cube in its absence.


title: Archimedes' principle

text: This means that the resultant upward force on the cube is equal to the weight of the fluid that would fit into the volume of the cube, and the downward force on the cube is its weight, in the absence of external forces.


title: Archimedes' principle

text: If two cubes are placed alongside each other with a face of each in contact, the pressures and resultant forces on the sides or parts thereof in contact are balanced and may be disregarded, as the contact surfaces are equal in shape, size and pressure distribution, therefore the buoyancy of two cubes in contact is the sum of the buoyancies of each cube. This analogy can be extended to an arbitrary number of cubes.


title: Archimedes' principle

text: An object of any shape can be approximated as a group of cubes in contact with each other, and as the size of the cube is decreased, the precision of the approximation increases. The limiting case for infinitely small cubes is the exact equivalence.


title: Archimedes' principle

text: Angled surfaces do not nullify the analogy as the resultant force can be split into orthogonal components and each dealt with in the same way.


title: Archimedes' principle

text: Archimedes' principle does not consider the surface tension (capillarity) acting on the body. Moreover, Archimedes' principle has been found to break down in complex fluids.


title: Archimedes' principle

text: There is an exception to Archimedes' principle known as the bottom (or side) case. This occurs when a side of the object is touching the bottom (or side) of the vessel it is submerged in, and no liquid seeps in along that side. In this case, the net force has been found to be different from Archimedes' principle, owing to the fact that since no fluid seeps in on that side, the symmetry of pressure is broken.


title: Archimedes' principle

text: Archimedes' principle shows the buoyant force and displacement of fluid. However, the concept of Archimedes' principle can be applied when considering why objects float. Proposition 5 of Archimedes' treatise "On Floating Bodies" states that


title: Archimedes' principle

text: In other words, for an object floating on a liquid surface (like a boat) or floating submerged in a fluid (like a submarine in water or dirigible in air) the weight of the displaced liquid equals the weight of the object. Thus, only in the special case of floating does the buoyant force acting on an object equal the objects weight. Consider a 1-ton block of solid iron. As iron is nearly eight times as dense as water, it displaces only 1/8 ton of water when submerged, which is not enough to keep it afloat. Suppose the same iron block is reshaped into a bowl. It still weighs 1 ton, but when it is put in water, it displaces a greater volume of water than when it was a block. The deeper the iron bowl is immersed, the more water it displaces, and the greater the buoyant force acting on it. When the buoyant force equals 1 ton, it will sink no farther.


title: Archimedes' principle

text: When any boat displaces a weight of water equal to its own weight, it floats. This is often called the "principle of flotation": A floating object displaces a weight of fluid equal to its own weight. Every ship, submarine, and dirigible must be designed to displace a weight of fluid at least equal to its own weight. A 10,000-ton ship's hull must be built wide enough, long enough and deep enough to displace 10,000 tons of water and still have some hull above the water to prevent it from sinking. It needs extra hull to fight waves that would otherwise fill it and, by increasing its mass, cause it to submerge. The same is true for vessels in air: a dirigible that weighs 100 tons needs to displace 100 tons of air. If it displaces more, it rises; if it displaces less, it falls. If the dirigible displaces exactly its weight, it hovers at a constant altitude.


title: Archimedes' principle

text: While they are related to it, the principle of flotation and the concept that a submerged object displaces a volume of fluid equal to its own volume are "not" Archimedes' principle. Archimedes' principle, as stated above, equates the "buoyant force" to the weight of the fluid displaced.


title: Archimedes' principle

text: One common point of confusion regarding Archimedes' principle is the meaning of displaced volume. Common demonstrations involve measuring the rise in water level when an object floats on the surface in order to calculate the displaced water. This measurement approach fails with a buoyant submerged object because the rise in the water level is directly related to the volume of the object and not the mass (except if the effective density of the object equals exactly the fluid density).


title: Archimedes' principle

text: Archimedes reportedly exclaimed "Eureka" after he realized how to detect whether a crown is made of impure gold. While he did not use Archimedes' principle in the widespread tale and used displaced water only for measuring the volume of the crown, there is an alternative approach using the principle: Balance the crown and pure gold on a scale in the air and then put the scale into water. According to Archimedes' principle, if the density of the crown differs from the density of pure gold, the scale will get out of balance under water.


title: Lanzarote

text: Lanzarote (, , ) is a Spanish island, the easternmost of the Canary Islands in the Atlantic Ocean. It is located approximately off the north coast of Africa and from the Iberian Peninsula. Covering , Lanzarote is the fourth-largest of the islands in the archipelago. With 152,289 inhabitants at the start of 2019, it is the third most populous Canary Island, after Tenerife and Gran Canaria. Located in the centre-west of the island is Timanfaya National Park, one of its main attractions. The island was declared a biosphere reserve by UNESCO in 1993. The island's capital is Arrecife, which lies on the eastern coastline. It is the smaller main island of the Province of Las Palmas.


title: Lanzarote

text: The first recorded name for the island, given by Italian-Majorcan cartographer Angelino Dulcert, was "Insula de Lanzarotus Marocelus", after the Genoese navigator Lancelotto Malocello, from which the modern name is derived. The island's name in the native Guanche language was "Tyterogaka" or "Tytheroygaka", which may mean "one that is all ochre" (referring to the island's predominant colour).


title: Lanzarote

text: Lanzarote is located north-east of Fuerteventura and just over from La Graciosa. The dimensions of the island are from north to south and from west to east. Lanzarote has of coastline, of which are sand, are beach, and the remainder is rocky. Its landscape includes the mountain ranges of Famara () in the north and Ajaches () to the south. South of the Famara massif is the El Jable desert, which separates Famara and Montañas del Fuego. The highest peak is Peñas del Chache, rising to above sea level. The "Tunnel of Atlantis", the largest underwater volcanic tunnel in the world, is part of the Cueva de los Verdes lava tube.


title: Lanzarote

text: Often called the "Island of Eternal Spring", Lanzarote has a subtropical-desert climate (BWh) according to the Köppen climatic classification. The small amount of precipitation is mainly concentrated in the winter. Rainfall during summer is a rare phenomenon and very often summers are completely dry without any precipitation. On average the island receives approximately 16 days of precipitation between December and February. Sometimes, the hot sirocco wind prevails, causing dry and dusty conditions across the island. Average precipitation in June and August is less than . It closely borders a tropical climate, with winter means of and summer means of .


title: Lanzarote

text: Lanzarote is the northernmost and easternmost island of the Canary Islands and has a volcanic origin. The island emerged about 15 million years ago as product of the Canary hotspot. The island, along with others, emerged after the breakup of the African and the American continental plates. The greatest recorded eruptions occurred between 1730 and 1736 in the area now designated Timanfaya National Park.


title: Lanzarote

text: There are five hundred different kinds of plants on the island, of which 17 species are endemic. These plants have adapted to the relative scarcity of water in the same way as succulents. They include the Canary Island date palm ("Phoenix canariensis"), which is found in damper areas of the north, the Canary Island pine ("Pinus canariensis"), ferns, and wild olive trees ("Olea europaea"). "Laurisilva" trees, which once covered the highest parts of Risco de Famara, are rarely found today. After winter rainfall, the vegetation comes to a colourful bloom between February and March.


title: Lanzarote

text: The vineyards of La Gería, Lanzarote "DO" wine region, are a protected area. Single vines are planted in pits wide and deep, with small stone walls around each pit. This agricultural technique is designed to harvest rainfall and overnight dew and to protect the plants from the winds.


title: Lanzarote

text: There are 180 different species of lichen-forming fungi. These survive in the suitable areas like rock surfaces, and promote weathering.


title: Lanzarote

text: Apart from the native bats and the mammals which accompanied humans to the island (including the dromedary, which was used for agriculture and is now a tourist attraction), there are few vertebrate species on Lanzarote. These include birds (such as falcons) and reptiles. Some interesting endemic animals are the "Gallotia" lizards and the blind "Munidopsis polymorpha" crabs found in the Jameos del Agua lagoon, which was formed by a volcanic eruption. The island is also home to one of two surviving populations of the threatened Canarian Egyptian vulture.


title: Lanzarote

text: The official natural symbols associated with Lanzarote are "Munidopsis polymorpha" (Blind crab) and "Euphorbia balsamifera" (Tabaiba dulce).


title: Lanzarote

text: , people live on Lanzarote, an increase of 9.163% from 2008 (). The seat of the island government ("Cabildo insular") is in the capital, Arrecife, which has a population of in 2019. According to the 2011 census, the majority of the inhabitants are Spanish (72.1%) with a sizeable number of residents of other nationalities, notably Britons (5.6%), Colombians (3.2%), Germans (3.1%) and Moroccans (3.1%). Other populous groups include Italians, Koreans, Cubans, and Romanians, which constitute a large proportion of the remaining 12.9% of the population.


title: Lanzarote

text: The island has an international airport, César Manrique-Lanzarote Airport, through which passengers travelled in 2018. Tourism has been the mainstay of the island's economy for over 40 years, the only other industry being agriculture.


title: Lanzarote

text: The island's main point of entry is César Manrique-Lanzarote Airport which, in 2018, handled passengers. It was renamed in 2019 to include the name of local artist César Manrique, in honour of the legacy he left behind on the island and coinciding with the centenary of his birth. The airport has two passenger terminal buildings, T1 and T2, with T2 being used exclusively for inter-island flights to and from the other Canary Islands. These inter-island flights are operated by regional airlines Binter Canarias and Canaryfly. Lanzarote Airport is located about southwest of the island's capital, Arrecife, to which it is connected by the LZ-2 road.


title: Lanzarote

text: Most of the goods arrive by sea through the Port of Arrecife, Puerto de los Mármoles. This port is also used by cruise ships.


title: Lanzarote

text: Furthermore, there are regular ferry lines that connect the Port of Arrecife with Las Palmas de Gran Canaria, Santa Cruz de Tenerife and Cadiz.


title: Lanzarote

text: Ferry services to the neighbouring island of Fuerteventura depart from Playa Blanca, the island's southernmost town.


title: Lanzarote

text: The LZ-1 road connects the capital, Arrecife, to the northernmost town of Órzola. The LZ-2 road connects Arrecife to the southernmost town of Playa Blanca. LZ-3 is a highway that acts as a ring road around Arrecife, connecting Puerto de los Mármoles on the northern side of the city to LZ-2 on the southern side. These three roads form the island's central road axis from which other roads connect to the rest of the island's towns, settlements and points of interest.


title: Lanzarote

text: Public transport on the island is provided by Arrecife Bus, operating under the name of Intercity Bus Lanzarote. The company operates 30 bus lines connecting the island's major and minor settlements, as well as serving the airport, and includes internal bus services in the towns of Playa Blanca, San Bartolomé and Tías. Most lines begin or end in the capital, Arrecife. The public bus service within the city of Arrecife is provided by the local council and consists of five lines, including one to the neighbouring town of Playa Honda.


title: Lanzarote

text: Lanzarote is believed to have been the first Canary Island to be settled. The Phoenicians may have visited or settled there, though no material evidence survives. The first known record came from Roman author Pliny the Elder in the encyclopaedia "Naturalis Historia" on an expedition to the Canary Islands. The names of the islands (then called "Insulae Fortunatae" or the "Fortunate Isles") were recorded as "Junonia" (Fuerteventura), "Canaria" (Gran Canaria), "Ninguaria" (Tenerife), "Junonia Major" (La Palma), "Pluvialia" (El Hierro), and "Capraria" (La Gomera). Lanzarote and Fuerteventura, the two easternmost Canary Islands, were only mentioned as the archipelago of the "purple islands". The Roman poet Lucan and the Greek astronomer and geographer Ptolemy gave their precise locations. It was settled by the Majos tribe of the Guanches. After the fall of the Western Roman Empire, interaction with the Canary Islands is unrecorded before 999, when the Arabs arrived at the island which they dubbed "al-Djezir al-Khalida" (among other names).


title: Lanzarote

text: In 1336, a ship arrived from Lisbon under the guidance of Genoese navigator Lancelotto Malocello, who used the alias "Lanzarote da Framqua". A fort was later built in the area of Montaña de Guanapay near today's Teguise. Castilian slaving expeditions in 1385 and 1393 seized hundreds of Guanches and sold them in Spain, initiating the slave trade in the islands. French explorer Jean de Béthencourt arrived in 1402, heading a private expedition under Castilian auspices. Bethencourt first visited the south of Lanzarote at Playas de Papagayo, and the French overran the island within a matter of months. The island lacked mountains and gorges to serve as hideouts for the remaining Guanche population, and so many Guanches were taken away as slaves that only 300 Guanche men were said to have remained.


title: Lanzarote

text: At the southern end of the Yaiza municipality, the first European settlement in the Canary Islands appeared in 1402 in the area known as "El Rubicón", where the conquest of the Archipelago began. In this place, the Cathedral of Saint Martial of Limoges was built. The cathedral was destroyed by English pirates in the 16th century. A diocese was moved in 1483 to Las Palmas de Gran Canaria (Roman Catholic Diocese of Canarias). In 1404, the Castilians (with the support of the King of Castile) came and fought the local Guanches, who were further decimated. The islands of Fuerteventura and El Hierro were later similarly conquered. In 1477, a decision by the royal council of Castile confirmed a grant of Lanzarote and Fuerteventura, with the smaller islands of Ferro and Gomera to the Castilian nobles Herrera, who held their fief until the end of the 18th century. In 1585, the Ottoman admiral Murat Reis temporarily seized Lanzarote. In the 17th century, pirates raided the island and took 1,000 inhabitants into slavery in Cueva de los Verdes.


title: Lanzarote

text: Lanzarote and Fuerteventura would be the main exporters of wheat and cereals to the central islands of the archipelago during the 16th, 17th and 18th centuries; Tenerife and Gran Canaria. Although this trade was almost never reversed for the inhabitants of Lanzarote and Fuerteventura (due to the fact that the landowners of these islands profited from this activity), producing periods of famine, so the population of these islands had to travel to Tenerife and Gran Canaria. The island of Tenerife is a major focus of attraction for the inhabitants of Lanzarote and Fuerteventura, hence the feeling of union that has always existed in the popular sphere with Tenerife.


title: Lanzarote

text: From 1730 to 1736, the island was hit by a series of volcanic eruptions, producing 32 new volcanoes in a stretch of . The priest of Yaiza, Don Andrés Lorenzo Curbelo, documented the eruption in detail until 1731. Lava covered a quarter of the island's surface, including the most fertile soil and 11 villages. 100 smaller volcanoes were located in the area called "Montañas del Fuego", the "Mountains of Fire". In 1768, drought affected the deforested island, and winter rains did not fall. Much of the population was forced to emigrate to Cuba and the Americas, including a group which formed a significant addition to the Spanish settlers in Texas at San Antonio de Bexar in 1731. Another volcanic eruption occurred within the range of Tiagua in 1824, which was less violent than the major eruption between 1730 and 1736.


title: Lanzarote

text: In 1927, Lanzarote and Fuerteventura became part of the province of Las Palmas. Several archaeological expeditions have uncovered the prehistoric settlement at the archaeologic site of "El Bebedero" in the village of Teguise. In one of those expeditions, by a team from the University of Las Palmas de Gran Canaria and a team from the University of Zaragoza, yielded about 100 Roman potsherds, nine pieces of metal, and one piece of glass. The artefacts were found in strata dated between the 1st and 4th centuries. They show that Romans did trade with the Canarians, though there is no evidence of settlements.


title: Lanzarote

text: The island has a UNESCO Biosphere Reserve protected site status. According to a report in the "Financial Times", this status was endangered by a local corruption scandal. Since May 2009, police have arrested the former president of Lanzarote, the former mayor of Arrecife and more than 20 politicians and businessmen in connection with illegal building permits along Lanzarote's coastline. UNESCO has threatened to revoke Lanzarote's Biosphere Reserve status, "if the developments are not respecting local needs and are impacting on the environment". The President of the Cabildo of Lanzarote denied "any threat to Lanzarote's UNESCO status".


title: Lanzarote

text: The most established festival on the island is held each year on 15 September in the village of Mancha Blanca, in honour of Our Lady of Dolours ("Virgen de los Dolores"), also called the "Virgin of the Volcanoes" (the Patron Saint of Lanzarote). People from all over the island participate in this pilgrimage, mostly dressed in traditional costumes.


title: Lanzarote

text: The island's only professional football team is UD Lanzarote, founded in 1970 who play at the 7,000 capacity Ciudad Deportiva de Lanzarote. The island is also home to smaller clubs CD Teguise and CD Orientación Marítima. In tennis, the Open Isla de Lanzarote was hosted between 2006 and 2008.


title: Neurology

text: Neurology (from , "string, nerve" and the suffix -logia, "study of") is the branch of medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the brain, the spinal cord and the peripheral nerves. Neurological practice relies heavily on the field of neuroscience, the scientific study of the nervous system.


title: Neurology

text: A neurologist is a physician specializing in neurology and trained to investigate, diagnose and treat neurological disorders. Neurologists treat a myriad of neurologic conditions, including stroke, seizures, movement disorders such as Parkinson's disease, autoimmune neurologic disorders such as multiple sclerosis, headache disorders like migraine and dementias such as Alzheimer's disease. Neurologists may also be involved in clinical research, clinical trials, and basic or translational research. While neurology is a nonsurgical specialty, its corresponding surgical specialty is neurosurgery.


title: Neurology

text: The academic discipline began between the 15th and 16th centuries with the work and research of many neurologists such as Thomas Willis, Robert Whytt, Matthew Baillie, Charles Bell, Moritz Heinrich Romberg, Duchenne de Boulogne, William A. Hammond, Jean-Martin Charcot, C. Miller Fisher and John Hughlings Jackson. Neo-Latin "neurologia" appeared in various texts from 1610 denoting an anatomical focus on the nerves (variably understood as vessels), and was most notably used by Willis, who preferred Greek νευρολογία.


title: Neurology

text: Many neurologists also have additional training or interest in one area of neurology, such as stroke, epilepsy, headache, neuromuscular disorders, sleep medicine, pain management, or movement disorders.


title: Neurology

text: In the United States and Canada, neurologists are physicians who have completed a postgraduate training period known as residency specializing in neurology after graduation from medical school. This additional training period typically lasts five years, with the first year devoted to training in internal medicine. On average, neurologists complete a total of eight to ten years of training. This includes four years of medical school, five years of residency and an optional one to two years of fellowship.


title: Neurology

text: While neurologists may treat general neurologic conditions, some neurologists go on to receive additional training focusing on a particular subspecialty in the field of neurology. These training programs are called fellowships, and are one to two years in duration. Subspecialties include brain injury medicine, clinical neurophysiology, epilepsy, neurodevelopmental disabilities, neuromuscular medicine, pain medicine, sleep medicine, neurocritical care, vascular neurology (stroke), behavioral neurology, child neurology, headache, multiple sclerosis, neuroimaging, neurooncology, and neurorehabilitation.


title: Neurology

text: In the United Kingdom and Ireland, neurology is a subspecialty of general (internal) medicine. After five years of medical school and two years as a Foundation Trainee, an aspiring neurologist must pass the examination for Membership of the Royal College of Physicians (or the Irish equivalent) and complete two years of core medical training before entering specialist training in neurology. Up to the 1960s, some intending to become neurologists would also spend two years working in psychiatric units before obtaining a diploma in psychological medicine. However, that was uncommon and, now that the MRCPsych takes three years to obtain, would no longer be practical. A period of research is essential, and obtaining a higher degree aids career progression. Many found it was eased after an attachment to the Institute of Neurology at Queen Square, London. Some neurologists enter the field of rehabilitation medicine (known as physiatry in the US) to specialise in neurological rehabilitation, which may include stroke medicine, as well as traumatic brain injuries.


title: Neurology

text: During a neurological examination, the neurologist reviews the patient's health history with special attention to the patient’s neurologic complaints. The patient then takes a neurological exam. Typically, the exam tests mental status, function of the cranial nerves (including vision), strength, coordination, reflexes, sensation and gait. This information helps the neurologist determine whether the problem exists in the nervous system and the clinical localization. Localization of the pathology is the key process by which neurologists develop their differential diagnosis. Further tests may be needed to confirm a diagnosis and ultimately guide therapy and appropriate management.


title: Neurology

text: Neurologists examine patients who are referred to them by other physicians in both the inpatient and outpatient settings. Neurologists begin their interactions with patients by taking a comprehensive medical history, and then performing a physical examination focusing on evaluating the nervous system. Components of the neurological examination include assessment of the patient's cognitive function, cranial nerves, motor strength, sensation, reflexes, coordination, and gait.


title: Neurology

text: In some instances, neurologists may order additional diagnostic tests as part of the evaluation. Commonly employed tests in neurology include imaging studies such as computed axial tomography (CAT) scans, magnetic resonance imaging (MRI), and ultrasound of major blood vessels of the head and neck. Neurophysiologic studies, including electroencephalography (EEG), needle electromyography (EMG), nerve conduction studies (NCSs) and evoked potentials are also commonly ordered. Neurologists frequently perform lumbar punctures to assess characteristics of a patient's cerebrospinal fluid. Advances in genetic testing have made genetic testing an important tool in the classification of inherited neuromuscular disease and diagnosis of many other neurogenetic diseases. The role of genetic influences on the development of acquired neurologic diseases is an active area of research.


title: Neurology

text: Some of the commonly encountered conditions treated by neurologists include headaches, radiculopathy, neuropathy, stroke, dementia, seizures and epilepsy, Alzheimer's disease, attention deficit/hyperactivity disorder, Parkinson's disease, Tourette's syndrome, multiple sclerosis, head trauma, sleep disorders, neuromuscular diseases, and various infections and tumors of the nervous system. Neurologists are also asked to evaluate unresponsive patients on life support to confirm brain death.


title: Neurology

text: Treatment options vary depending on the neurological problem. They can include referring the patient to a physiotherapist, prescribing medications, or recommending a surgical procedure.


title: Neurology

text: Some neurologists specialize in certain parts of the nervous system or in specific procedures. For example, clinical neurophysiologists specialize in the use of EEG and intraoperative monitoring to diagnose certain neurological disorders. Other neurologists specialize in the use of electrodiagnostic medicine studies – needle EMG and NCSs. In the US, physicians do not typically specialize in all the aspects of clinical neurophysiology – i.e. sleep, EEG, EMG, and NCSs. The American Board of Clinical Neurophysiology certifies US physicians in general clinical neurophysiology, epilepsy, and intraoperative monitoring. The American Board of Electrodiagnostic Medicine certifies US physicians in electrodiagnostic medicine and certifies technologists in nerve-conduction studies. Sleep medicine is a subspecialty field in the US under several medical specialties including anesthesiology, internal medicine, family medicine, and neurology. Neurosurgery is a distinct specialty that involves a different training path, and emphasizes the surgical treatment of neurological disorders.


title: Neurology

text: Also, many nonmedical doctors, those with doctoral degrees (usually PhDs) in subjects such as biology and chemistry, study and research the nervous system. Working in laboratories in universities, hospitals, and private companies, these neuroscientists perform clinical and laboratory experiments and tests to learn more about the nervous system and find cures or new treatments for diseases and disorders.


title: Neurology

text: A great deal of overlap occurs between neuroscience and neurology. Many neurologists work in academic training hospitals, where they conduct research as neuroscientists in addition to treating patients and teaching neurology to medical students.


title: Neurology

text: Neurologists are responsible for the diagnosis, treatment, and management of all the conditions mentioned above. When surgical or endovascular intervention is required, the neurologist may refer the patient to a neurosurgeon or an interventional neuroradiologist. In some countries, additional legal responsibilities of a neurologist may include making a finding of brain death when it is suspected that a patient has died. Neurologists frequently care for people with hereditary (genetic) diseases when the major manifestations are neurological, as is frequently the case. Lumbar punctures are frequently performed by neurologists. Some neurologists may develop an interest in particular subfields, such as stroke, dementia, movement disorders, neurointensive care, headaches, epilepsy, sleep disorders, chronic pain management, multiple sclerosis, or neuromuscular diseases.


title: Neurology

text: Some overlap also occurs with other specialties, varying from country to country and even within a local geographic area. Acute head trauma is most often treated by neurosurgeons, whereas sequelae of head trauma may be treated by neurologists or specialists in rehabilitation medicine. Although stroke cases have been traditionally managed by internal medicine or hospitalists, the emergence of vascular neurology and interventional neuroradiology has created a demand for stroke specialists. The establishment of Joint Commission-certified stroke centers has increased the role of neurologists in stroke care in many primary, as well as tertiary, hospitals. Some cases of nervous system infectious diseases are treated by infectious disease specialists. Most cases of headache are diagnosed and treated primarily by general practitioners, at least the less severe cases. Likewise, most cases of sciatica are treated by general practitioners, though they may be referred to neurologists or surgeons (neurosurgeons or orthopedic surgeons). Sleep disorders are also treated by pulmonologists and psychiatrists. Cerebral palsy is initially treated by pediatricians, but care may be transferred to an adult neurologist after the patient reaches a certain age. Physical medicine and rehabilitation physicians may treat patients with neuromuscular diseases with electrodiagnostic studies (needle EMG and nerve-conduction studies) and other diagnostic tools. In the United Kingdom and other countries, many of the conditions encountered by older patients such as movement disorders, including Parkinson's disease, stroke, dementia, or gait disorders, are managed predominantly by specialists in geriatric medicine.


title: Neurology

text: Clinical neuropsychologists are often called upon to evaluate brain-behavior relationships for the purpose of assisting with differential diagnosis, planning rehabilitation strategies, documenting cognitive strengths and weaknesses, and measuring change over time (e.g., for identifying abnormal aging or tracking the progression of a dementia)


title: Neurology

text: In some countries such as the United States and Germany, neurologists may subspecialize in clinical neurophysiology, the field responsible for EEG and intraoperative monitoring, or in electrodiagnostic medicine nerve conduction studies, EMG, and evoked potentials. In other countries, this is an autonomous specialty (e.g., United Kingdom, Sweden, Spain).


title: Neurology

text: In the past, prior to the advent of more advanced diagnostic techniques such as MRI some neurologists have considered psychiatry and neurologic to overlap. Although mental illnesses are believed by many to be neurological disorders affecting the central nervous system, traditionally they are classified separately, and treated by psychiatrists. In a 2002 review article in the "American Journal of Psychiatry", Professor Joseph B. Martin, Dean of Harvard Medical School and a neurologist by training, wrote, "the separation of the two categories is arbitrary, often influenced by beliefs rather than proven scientific observations. And the fact that the brain and mind are one makes the separation artificial anyway".


title: Neurology

text: Neurological disorders often have psychiatric manifestations, such as post-stroke depression, depression and dementia associated with Parkinson's disease, mood and cognitive dysfunctions in Alzheimer's disease, and Huntington disease, to name a few. Hence, the sharp distinction between neurology and psychiatry is not always on a biological basis. The dominance of psychoanalytic theory in the first three-quarters of the 20th century has since then been largely replaced by a focus on pharmacology. Despite the shift to a medical model, brain science has not advanced to a point where scientists or clinicians can point to readily discernible pathological lesions or genetic abnormalities that in and of themselves serve as reliable or predictive biomarkers of a given mental disorder.


title: Neurology

text: The emerging field of neurological enhancement highlights the potential of therapies to improve such things as workplace efficacy, attention in school, and overall happiness in personal lives. However, this field has also given rise to questions about neuroethics and the psychopharmacology of lifestyle drugs can have negative and positive effects on neurology because different types


title: Slab City, California

text: Slab City, also called The Slabs, is an unincorporated, off-the-grid alternative lifestyle community consisting largely of snowbirds in the Salton Trough area of the Sonoran Desert, in Imperial County, California. It took its name from concrete slabs that remained after the World War II Marine Corps Camp Dunlap training camp was torn down. Slab City is known for attracting people who want to live outside mainstream society.


title: Slab City, California

text: Prior to the United States' official entry into World War II, the United States Marine Corps planned a training ground for field and anti-aircraft artillery units in an area accessible by aircraft taking off from carriers near San Diego. To create the training base, were obtained. The government announced that the base was to be named after Marine Corps Brigadier General Robert Henry Dunlap. After construction of Camp Dunlap was completed, it was commissioned on October 15, 1942. The camp had fully functioning buildings, water, roads, and sewage collections. The base was used for three years during the war. By 1949, military operations at Camp Dunlap had been greatly reduced, but a skeleton crew continued on until the base was dismantled. By 1956, all buildings had been dismantled, but the slabs remained.


title: Slab City, California

text: The area that is now Slab City was the artillery training range for the Camp. It was first settled by a few veterans who had worked at the Marine base, followed later by drifters – then recreational vehicle owners, searching for free camping spots outside Palm Springs. Current residents refer to themselves as "Slabbies" while tourists are called "Normies".


title: Slab City, California

text: As of October 6, 1961, a quitclaim deed conveying the land to the State of California was issued by the Department of Defense as it was determined the land was no longer required. The deed did not contain any restrictions, recapture clauses or restoration provisions. All of the former Camp Dunlap buildings had been removed. The remaining slabs were not proposed for removal. Later, legislation required that revenue generated from this property go to the California State Teachers' Retirement System.


title: Slab City, California

text: Slab City's popularity surged after an article was printed in "Trailer Life" and "RV Magazine" around 1984. A 1988 "San Diego Reader" reports there were no more than 600–700 RVs around 1983, and one resident estimated there were about 2000 trailers when he was interviewed in March, 1988.


title: Slab City, California

text: Leonard Knight, an early settler who created the Salvation Mountain art installation, was featured in Sean Penn's "Into the Wild", released in 2007. An obituary of Knight stated that he "spent almost 30 years building the colorful mountain ... Built out of adobe and donated paint, Knight worked on the mountain all day, every day. He even slept at the mountain's base in the back of a pick-up truck, with no electricity or running water".


title: Slab City, California

text: An article in "Smithsonian" magazine in October 2018 referred to the community as a "Squatters’ Paradise" which locals consider to be "one of America's last free places". The article said of the population: "There are clearly people there who don’t want to be found, so there’s something about disappearing, and the desert offers that kind of opportunity".


title: Slab City, California

text: Slab City is widespread, on roughly of public land. Located near the east shore of the Salton Sea, Slab City is northeast of San Diego and southeast of Los Angeles. It is about from Mexico. To the east of Slab City is Coachella Canal, which is fenced, but gets cut open especially at Slab City, according to the Coachella Valley Water District.


title: Slab City, California

text: The area has a large amount of sunshine year round, due to its stable descending air and high pressure. According to the Köppen climate classification system, Niland has a hot desert climate, "BWh" on climate maps.


title: Slab City, California

text: "The Washington Post" reported in 2020 that population is seasonal, and balloons up to about 4,000 during the winter, by some estimates, and dwindles to about 150 in the summer. Since the 1950s, Slab City has drawn a variety of people, such as anarchists, artists, eccentrics, outcasts, retirees, and the impoverished. A 1990 "Chicago Tribune" article, by a journalist who stayed in the camp for a week, estimated that winter residents (at the time) were mostly senior citizens over 60 years old. It is a "popular winter destination for transients." Slab City is used by recreational vehicle owners, travellers, and squatters from across North America, including Canada.


title: Slab City, California

text: According to the "San Diego Union-Tribune"'s Fred Dickey in 2012, the most common source of income among the permanent residents is "probably" SSI checks. In 2020, "Ranker" indicated that Slab City's income mainly comes from tourists and donations. In 1995, almost every resident of Slab City collected disability benefits, social security or unemployment. Another steady source of income at the time was selling salvaged goods to visitors.


title: Slab City, California

text: Many residents use generators or solar panels to generate electricity. Clean water is dispensed from a tank at the community church. The closest body of civilization with proper law enforcement is approximately southwest of Slab City, in Niland, where residents often went for basic shopping as of 1990. Residents were still obtaining essentials from Niland, a town of about 1,000, 30 years later in 2020.


title: Slab City, California

text: During the 2020 COVID-19 pandemic, most tourist destinations were closed. This had economic ramifications for Slab City, as well as its availability of food and water, which relied in part on tourist donations. Residents are divided on whether to follow or defy government guidelines, complicated by a lack of health infrastructure and insurance. In May 2020, Imperial County had 55 confirmed cases of the coronavirus, out of 417 tests.


title: Slab City, California

text: Slab City has a free lending library, an outdoor music venue called The Range and Salvation Mountain.


title: Slab City, California

text: The settlement also has an internet cafe, a hostel, and a skatepark built inside what remains of the military base swimming pool.


title: Slab City, California

text: During the 2020 pandemic, most tourist destinations, including Salvation Mountain, The Range, and Slab City's Library, have been closed.


title: Slab City, California

text: Located just east of California State Route 111, the entrance to Slab City is easily recognized by the colorful Salvation Mountain, which is a small hill approximately three stories tall and entirely covered in latex paint, concrete and adobe, and festooned with Bible verses. It was a project built over two decades by Leonard Knight. The work is a 50 ft-tall piece of religious folk art, "an unofficial centrepiece for the community and [cementing] the area’s anarchic creative identity", according to a 2020 report.


title: Slab City, California

text: The current Salvation Mountain is actually the second construction to occupy the site; Knight began the first Salvation Mountain in 1984, using highly unstable construction methods that allowed the mountain to collapse in 1989. Knight was not discouraged; he rebuilt the structure using better materials and engineering, including adobe mixed with straw.


title: Slab City, California

text: Before his death on February 10, 2014, Knight had been living in a nursing home. He was able to visit Salvation Mountain for the last time in May 2013; the visit was recorded by KPBS (TV).


title: Slab City, California

text: "East Jesus" is an experimental and habitable art installation located in the Slab City area. There is no religious connotation in the name "East Jesus" – it is a colloquialism for a place in the middle of nowhere beyond the edge of serviceability. The off-grid facility operates with no municipal utilities.


title: Slab City, California

text: In early 2007, Charlie Russell left his job in the technology industry, packed all his belongings into a shipping container, and sent it to a trash-strewn field, where he began to surround his two cars with sculptures. Russell, often called Container Charlie, renamed this settlement site "East Jesus". He died in May 2011. The Chasterus Foundation, a 501(c)(3) non-profit formed after his death in 2011, has since guided the curation and expansion of "East Jesus."


title: Slab City, California

text: "East Jesus" features a variety of experimental art, such as live events, performance art, music, photography, and most prominently sculptures. Works are continually added, and degrade quickly in the desert climate, despite the presence of caretakers. One such volunteer referred to it, and Slab City as a whole, as a ‘salvagepunk’ ethos. "East Jesus" pieces are described as decaying, or growing, but always in a state of transformation, unlike traditional galleries; due both to the intense climate, and the thousands of contributing artists who have added to the installation. In 2014, live-in staff were giving dozens of free tours, and hosted visiting artists and overnight guests.


title: Slab City, California

text: The Range is an open-air nightclub complete with stage, lights, amplifiers, and speakers, with tattered couches and old chairs for seating. Every Saturday night at around dusk, locals and visitors meet for a talent show that features permanent resident musicians and anyone else who wants to get on stage and perform. The venue is run by old-time resident William Ammon, known as "Builder Bill". Ammon's wife, Robin Ammon, collected old prom dresses for people to wear; these are used when the community puts on a prom, because many residents have never been able to actually attend one.


title: Slab City, California

text: Dirt roads are graded by Imperial County, and it's regularly patrolled by the Imperial County Sheriff's Office, as well as by Border Patrol agents searching for illegal immigrants; Slab City is about from Mexico. Fire service for Slab City is provided by the Niland Fire Department. School buses come from nearby communities to pick up the few children there.


title: Slab City, California

text: Slab City is divided into a handful of neighborhoods with different characteristics. As of 2020, the community is largely divided into two: "East Jesus" and "Slab City". Thousands of campers and RV owners, many retired, use the site during the winter months. The "snowbirds" stay only for the winter before migrating north in spring, to cooler climates. Despite the high temperatures, there are about 150 permanent residents of Slab City. Some of these "Slabbers", or "Year-Rounders", derive their living from government programs and have been driven to Slab City by poverty or job loss. Others have voluntarily moved, to learn how to live off the grid, or otherwise be isolated. "Builder Bill" Ammon described "a kind of segregation" between the older residents, who would exchange goods and services, and young residents, who are sometimes "ill-equipped" for self-sufficiency, or turn to petty theft and drug use.


title: Slab City, California

text: As of a January 2020 report, Slab City is composed of "more than a dozen individual neighborhoods ... small camps of people with their own particular rules and culture". Amenities include The Range, a makeshift library, RV rental units, an internet cafe, and establishments which sell food; though most shopping is done at the town of Niland. One resident is reported to have run a weekly self-help group for women in the community. Residents talked about using CB radio as a bulletin board and adopting radio handles when they spoke to the Chicago Tribune in 1990. In 2005, a resident told "Los Angeles Times" correspondent for On The Streets documentary how he can just live however he wants.


title: Slab City, California

text: During the COVID-19 pandemic, residents have been heavily impacted by the loss of tourist income, which also provided food and water. Social distancing is also a difficulty, as many residents work closely to trade and maintain services. The pandemic is complicated by the elderly population, no health infrastructure within Slab City (the nearest hospital is 40 minutes away, in Brawley), a lack of insurance, a lack of running water and sanitation, and anti-governmental or conspiratorial beliefs. Residents raised concerns over a past failure to contain an outbreak of canine parvo. As of April 2020, Imperial County had not provided any specific assistance for vulnerable communities.


title: Slab City, California

text: Crystal meth is fairly common and accounts for much of the crime in Slab City. In 2015, the "New York Times" reported that the usual cause for police response to Slab City is over camping boundary disputes, sometimes burglary, but that methamphetamine use is a recurrent problem. In December 2019, during the two-day Imperial Valley fugitive-seeking effort, Operation Valley Grinch, four fugitives hiding in Slab City were apprehended. The locals also cut the fence to unlawfully use Coachella Canal as a swimming spot.


title: Slab City, California

text: The land is owned by the State of California. However, it is also reported that the land was purchased by a building contractor in September 1993. As of 2021, California had not yet decided to sell the land, but the Lands Commission is considering having the land appraised, and, if needed, allow for cleanup due to military waste from the 1950s.


title: Slab City, California

text: In 2015, several residents formed the Slab City Community Group in an effort to prevent a sale or to obtain 450 acres of Slab City in a trust, though this was contentious with other residents. A May 2020 article confirmed that the state was hoping to sell the land. "A sale could potentially go to energy companies ... Many residents worry that a deal could leave them without a community or place to live, as the lawless Slab City has become the last resort for so many".


title: Naomi Ackie

text: Naomi Ackie (born 2 November 1992) is an English actress. She made her television debut as Jen in the "Doctor Who" episode "Face the Raven" (2015). For her role as Bonnie on the television dark comedy-drama series "The End of the F***ing World", she received the British Academy Television Award for Best Supporting Actress in 2020. Ackie is well known for her role as Jannah in the film "" (2019). In 2021, she had a main role on the third season of "Master of None". She will portray American singer Whitney Houston in the biopic "I Wanna Dance with Somebody", set to be released in late 2022.


title: Naomi Ackie

text: Naomi Ackie was born and raised in Walthamstow, London, the daughter of second-generation immigrants from Grenada. Her father was a Transport for London employee and her mother worked for the National Health Service. She is one of three children and has an older brother and sister. She went to Walthamstow School for Girls.


title: Naomi Ackie

text: Her first role was at the age of 11, playing the angel Gabriel in a school nativity play. She studied at the Royal Central School of Speech and Drama and graduated in 2014.


title: Naomi Ackie

text: Ackie's breakthrough film role was in "Lady Macbeth" (2016), for which she won the British Independent Film Award for Most Promising Newcomer in 2017. She subsequently appeared in Idris Elba's directorial debut "Yardie" (2018) and "" (2019). She also portrayed Bonnie in the second season of Netflix's black comedy series "The End of the F***ing World", and a school inspector in "Education", an hour-long drama part of Steve McQueen's anthology film series "Small Axe".


title: Naomi Ackie

text: Ackie will portray American singer Whitney Houston in the upcoming biographical film "I Wanna Dance with Somebody". She is also committed to star in Zoë Kravitz's directorial debut "Pussy Island", co-starring Channing Tatum, and in Bong Joon-ho's "Mickey 17", based on Edward Ashton's science-fiction novel, alongside Robert Pattinson, Toni Collette and Mark Ruffalo.


title: Torus

text: In geometry, a torus (plural tori, colloquially donut or doughnut) is a surface of revolution generated by revolving a circle in three-dimensional space about an axis that is coplanar with the circle.


title: Torus

text: If the axis of revolution does not touch the circle, the surface has a ring shape and is called a torus of revolution. If the axis of revolution is tangent to the circle, the surface is a horn torus. If the axis of revolution passes twice through the circle, the surface is a spindle torus. If the axis of revolution passes through the center of the circle, the surface is a degenerate torus, a double-covered sphere. If the revolved curve is not a circle, the surface is called a "toroid", as in a square toroid.


title: Torus

text: Real-world objects that approximate a torus of revolution include swim rings, inner tubes and ringette rings. Eyeglass lenses that combine spherical and cylindrical correction are toric lenses.


title: Torus

text: A torus should not be confused with a "solid torus", which is formed by rotating a disk, rather than a circle, around an axis. A solid torus is a torus plus the volume inside the torus. Real-world objects that approximate a "solid torus" include O-rings, non-inflatable lifebuoys, ring doughnuts, and bagels.


title: Torus

text: In topology, a ring torus is homeomorphic to the Cartesian product of two circles: formula_1, and the latter is taken to be the definition in that context. It is a compact 2-manifold of genus 1. The ring torus is one way to embed this space into Euclidean space, but another way to do this is the Cartesian product of the embedding of formula_2 in the plane with itself. This produces a geometric object called the Clifford torus, a surface in 4-space.


title: Torus

text: In the field of topology, a torus is any topological space that is homeomorphic to a torus. The surface of a coffee cup and a doughnut are both topological tori with genus one.


title: Torus

text: An example of a torus can be constructed by taking a rectangular strip of flexible material, for example, a rubber sheet, and joining the top edge to the bottom edge, and the left edge to the right edge, without any half-twists (compare Möbius strip).


title: Torus

text: Angle represents rotation around the tube, whereas represents rotation around the torus' axis of revolution. is known as the "major radius" and is known as the "minor radius". The ratio divided by is known as the "aspect ratio". The typical doughnut confectionery has an aspect ratio of about 3 to 2.


title: Torus

text: of this torus is diffeomorphic (and, hence, homeomorphic) to a product of a Euclidean open disk and a circle. The volume of this solid torus and the surface area of its torus are easily computed using Pappus's centroid theorem, giving:


title: Torus

text: These formulas are the same as for a cylinder of length and radius , obtained from cutting the tube along the plane of a small circle, and unrolling it by straightening out (rectifying) the line running around the center of the tube. The losses in surface area and volume on the inner side of the tube exactly cancel out the gains on the outer side.


title: Torus

text: Expressing the surface area and the volume by the distance of an outermost point on the surface of the torus to the center, and the distance of an innermost point to the center (so that and ), yields


title: Torus

text: As a torus is the product of two circles, a modified version of the spherical coordinate system is sometimes used.


title: Torus

text: In traditional spherical coordinates there are three measures, , the distance from the center of the coordinate system, and and , angles measured from the center point.


title: Torus

text: As a torus has, effectively, two center points, the centerpoints of the angles are moved; measures the same angle as it does in the spherical system, but is known as the "toroidal" direction. The center point of is moved to the center of , and is known as the "poloidal" direction. These terms were first used in a discussion of the Earth's magnetic field, where "poloidal" was used to denote "the direction toward the poles".


title: Torus

text: In modern use, toroidal and poloidal are more commonly used to discuss magnetic confinement fusion devices.


title: Torus

text: Topologically, a torus is a closed surface defined as the product of two circles: "S" × "S". This can be viewed as lying in C and is a subset of the 3-sphere "S" of radius √2. This topological torus is also often called the Clifford torus. In fact, "S" is filled out by a family of nested tori in this manner (with two degenerate circles), a fact which is important in the study of "S" as a fiber bundle over "S" (the Hopf bundle).


title: Torus

text: The surface described above, given the relative topology from formula_10, is homeomorphic to a topological torus as long as it does not intersect its own axis. A particular homeomorphism is given by stereographically projecting the topological torus into formula_10 from the north pole of "S".


title: Torus

text: or, equivalently, as the quotient of the unit square by pasting the opposite edges together, described as a fundamental polygon "ABA""B".


title: Torus

text: The fundamental group of the torus is just the direct product of the fundamental group of the circle with itself:


title: Torus

text: Intuitively speaking, this means that a closed path that circles the torus' "hole" (say, a circle that traces out a particular latitude) and then circles the torus' "body" (say, a circle that traces out a particular longitude) can be deformed to a path that circles the body and then the hole. So, strictly 'latitudinal' and strictly 'longitudinal' paths commute. An equivalent statement may be imagined as two shoelaces passing through each other, then unwinding, then rewinding.


title: Torus

text: If a torus is punctured and turned inside out then another torus results, with lines of latitude and longitude interchanged. This is equivalent to building a torus from a cylinder, by joining the circular ends together, in two ways: around the outside like joining two ends of a garden hose, or through the inside like rolling a sock (with the toe cut off). Additionally, if the cylinder was made by gluing two opposite sides of a rectangle together, choosing the other two sides instead will cause the same reversal of orientation.


title: Torus

text: The first homology group of the torus is isomorphic to the fundamental group (this follows from Hurewicz theorem since the fundamental group is abelian).


title: Torus

text: The 2-torus double-covers the 2-sphere, with four ramification points. Every conformal structure on the 2-torus can be represented as a two-sheeted cover of the 2-sphere. The points on the torus corresponding to the ramification points are the Weierstrass points. In fact, the conformal type of the torus is determined by the cross-ratio of the four points.


title: Torus

text: The torus has a generalization to higher dimensions, the , often called the or for short. (This is the more typical meaning of the term ""n"-torus", the other referring to "n" holes or of genus "n".) Recalling that the torus is the product space of two circles, the "n"-dimensional torus is the product of "n" circles. That is:


title: Torus

text: The standard 1-torus is just the circle: formula_15. The torus discussed above is the standard 2-torus, formula_16. And similar to the 2-torus, the "n"-torus, formula_17 can be described as a quotient of formula_18 under integral shifts in any coordinate. That is, the "n"-torus is formula_18 modulo the action of the integer lattice formula_20 (with the action being taken as vector addition). Equivalently, the "n"-torus is obtained from the "n"-dimensional hypercube by gluing the opposite faces together.


title: Torus

text: An "n"-torus in this sense is an example of an "n-"dimensional compact manifold. It is also an example of a compact abelian Lie group. This follows from the fact that the unit circle is a compact abelian Lie group (when identified with the unit complex numbers with multiplication). Group multiplication on the torus is then defined by coordinate-wise multiplication.


title: Torus

text: Toroidal groups play an important part in the theory of compact Lie groups. This is due in part to the fact that in any compact Lie group "G" one can always find a maximal torus; that is, a closed subgroup which is a torus of the largest possible dimension. Such maximal tori "T" have a controlling role to play in theory of connected "G". Toroidal groups are examples of protori, which (like tori) are compact connected abelian groups, which are not required to be manifolds.


title: Torus

text: Automorphisms of "T" are easily constructed from automorphisms of the lattice formula_20, which are classified by invertible integral matrices of size "n" with an integral inverse; these are just the integral matrices with determinant ±1. Making them act on formula_18 in the usual way, one has the typical "toral automorphism" on the quotient.


title: Torus

text: The fundamental group of an "n"-torus is a free abelian group of rank "n". The "k"-th homology group of an "n"-torus is a free abelian group of rank "n" choose "k". It follows that the Euler characteristic of the "n"-torus is 0 for all "n". The cohomology ring "H"(formula_17, Z) can be identified with the exterior algebra over the Z-module formula_20 whose generators are the duals of the "n" nontrivial cycles.


title: Torus

text: As the "n"-torus is the "n"-fold product of the circle, the "n"-torus is the configuration space of "n" ordered, not necessarily distinct points on the circle. Symbolically, formula_25. The configuration space of "unordered", not necessarily distinct points is accordingly the orbifold formula_26, which is the quotient of the torus by the symmetric group on "n" letters (by permuting the coordinates).


title: Torus

text: For "n" = 2, the quotient is the Möbius strip, the edge corresponding to the orbifold points where the two coordinates coincide. For "n" = 3 this quotient may be described as a solid torus with cross-section an equilateral triangle, with a twist; equivalently, as a triangular prism whose top and bottom faces are connected with a 1/3 twist (120°): the 3-dimensional interior corresponds to the points on the 3-torus where all 3 coordinates are distinct, the 2-dimensional face corresponds to points with 2 coordinates equal and the 3rd different, while the 1-dimensional edge corresponds to points with all 3 coordinates identical.


title: Torus

text: These orbifolds have found significant applications to music theory in the work of Dmitri Tymoczko and collaborators (Felipe Posada, Michael Kolinas, et al.), being used to model musical triads.


title: Torus

text: A flat torus is a torus with the metric inherited from its representation as the quotient, formula_27/L, where L is a discrete subgroup of formula_27 isomorphic to formula_29. This gives the quotient the structure of a Riemannian manifold. Perhaps the simplest example of this is when : formula_30, which can also be described as the Cartesian plane under the identifications . This particular flat torus (and any uniformly scaled version of it) is known as the "square" flat torus.


title: Torus

text: This metric of the square flat torus can also be realised by specific embeddings of the familiar 2-torus into Euclidean 4-space or higher dimensions. Its surface has zero Gaussian curvature everywhere. Its surface is flat in the same sense that the surface of a cylinder is flat. In 3 dimensions, one can bend a flat sheet of paper into a cylinder without stretching the paper, but this cylinder cannot be bent into a torus without stretching the paper (unless some regularity and differentiability conditions are given up, see below).


title: Torus

text: A simple 4-dimensional Euclidean embedding of a rectangular flat torus (more general than the square one) is as follows:


title: Torus

text: where "R" and "P" are positive constants determining the aspect ratio. It is diffeomorphic to a regular torus but not isometric. It can not be analytically embedded (smooth of class ) into Euclidean 3-space. Mapping it into "3"-space requires one to stretch it, in which case it looks like a regular torus. For example, in the following map:


title: Torus

text: If "R" and "P" in the above flat torus parametrization form a unit vector then "u", "v", and 0 < "η" < /2 parameterize the unit 3-sphere as Hopf coordinates. In particular, for certain very specific choices of a square flat torus in the 3-sphere "S", where above, the torus will partition the 3-sphere into two congruent solid tori subsets with the aforesaid flat torus surface as their common boundary. One example is the torus T defined by


title: Torus

text: Other tori in "S" having this partitioning property include the square tori of the form "Q"⋅T, where "Q" is a rotation of 4-dimensional space formula_34, or in other words "Q" is a member of the Lie group SO(4).


title: Torus

text: It is known that there exists no "C" (twice continuously differentiable) embedding of a flat torus into 3-space. (The idea of the proof is to take a large sphere containing such a flat torus in its interior, and shrink the radius of the sphere until it just touches the torus for the first time. Such a point of contact must be a tangency. But that would imply that part of the torus, since it has zero curvature everywhere, must lie strictly outside the sphere, which is a contradiction.) On the other hand, according to the Nash-Kuiper theorem, which was proven in the 1950s, an isometric "C" embedding exists. This is solely an existence proof and does not provide explicit equations for such an embedding.


title: Torus

text: In April 2012, an explicit "C" (continuously differentiable) embedding of a flat torus into 3-dimensional Euclidean space formula_10 was found. It is a flat torus in the sense that as metric spaces, it is isometric to a flat square torus. It is similar in structure to a fractal as it is constructed by repeatedly corrugating an ordinary torus. Like fractals, it has no defined Gaussian curvature. However, unlike fractals, it does have defined surface normals, yielding a so-called "smooth fractal". The key to obtain the smoothness of this corrugated torus is to have the amplitudes of successive corrugations decreasing faster than their "wavelengths". (These infinitely recursive corrugations are used only for embedding into three dimensions; they are not an intrinsic feature of the flat torus.) This is the first time that any such embedding was defined by explicit equations or depicted by computer graphics.


title: Torus

text: In the theory of surfaces there is another object, the "genus" "g" surface. Instead of the product of "n" circles, a genus "g" surface is the connected sum of "g" two-tori. To form a connected sum of two surfaces, remove from each the interior of a disk and "glue" the surfaces together along the boundary circles. To form the connected sum of more than two surfaces, sum two of them at a time until they are all connected. In this sense, a genus "g" surface resembles the surface of "g" doughnuts stuck together side by side, or a 2-sphere with "g" handles attached.


title: Torus

text: As examples, a genus zero surface (without boundary) is the two-sphere while a genus one surface (without boundary) is the ordinary torus. The surfaces of higher genus are sometimes called "n"-holed tori (or, rarely, "n"-fold tori). The terms double torus and triple torus are also occasionally used.


title: Torus

text: The classification theorem for surfaces states that every compact connected surface is topologically equivalent to either the sphere or the connect sum of some number of tori, disks, and real projective planes.


title: Torus

text: Polyhedra with the topological type of a torus are called toroidal polyhedra, and have Euler characteristic "V" − "E" + "F" = 0. For any number of holes, the formula generalizes to "V" − "E" + "F" = 2 − 2"N", where "N" is the number of holes.


title: Torus

text: The term "toroidal polyhedron" is also used for higher-genus polyhedra and for immersions of toroidal polyhedra.


title: Torus

text: The homeomorphism group (or the subgroup of diffeomorphisms) of the torus is studied in geometric topology. Its mapping class group (the connected components of the homeomorphism group) is surjective onto the group formula_36 of invertible integer matrices, which can be realized as linear maps on the universal covering space formula_18 that preserve the standard lattice formula_20 (this corresponds to integer coefficients) and thus descend to the quotient.


title: Torus

text: At the level of homotopy and homology, the mapping class group can be identified as the action on the first homology (or equivalently, first cohomology, or on the fundamental group, as these are all naturally isomorphic; also the first cohomology group generates the cohomology algebra:


title: Torus

text: Since the torus is an Eilenberg–MacLane space "K"("G", 1), its homotopy equivalences, up to homotopy, can be identified with automorphisms of the fundamental group); all homotopy equivalences of the torus can be realized by homeomorphisms – every homotopy equivalence is homotopic to a homeomorphism.


title: Torus

text: Thus the short exact sequence of the mapping class group splits (an identification of the torus as the quotient of formula_18 gives a splitting, via the linear maps, as above):


title: Torus

text: The mapping class group of higher genus surfaces is much more complicated, and an area of active research.


title: Torus

text: The torus's chromatic number is seven, meaning every graph that can be embedded on the torus has a chromatic number of at most seven. (Since the complete graph formula_42 can be embedded on the torus, and formula_43, the upper bound is tight.) Equivalently, in a torus divided into regions, it is always possible to color the regions using no more than seven colors so that no neighboring regions are the same color. (Contrast with the four color theorem for the plane.)


title: Torus

text: In combinatorial mathematics, a "de Bruijn torus" is an array of symbols from an alphabet (often just 0 and 1) that contains every "m"-by-"n" matrix exactly once. It is a torus because the edges are considered wraparound for the purpose of finding matrices. Its name comes from the De Bruijn sequence, which can be considered a special case where "n" is 1 (one dimension).


title: Torus

text: The first 11 numbers of parts, for 0 ≤ "n" ≤ 10 (including the case of "n" = 0, not covered by the above formulas), are as follows:


title: Astute-class submarine

text: The "Astute" class is the latest class of nuclear-powered fleet submarines (SSNs) in service with the Royal Navy. The boats are being constructed by BAE Systems Submarines at Barrow-in-Furness. Seven boats will be constructed: the first of class, , was launched by Camilla, Duchess of Cornwall, in 2007, commissioned in 2010, and declared fully operational in May 2014. The "Astute" class is the replacement for the fleet submarines in Royal Navy service.


title: Astute-class submarine

text: The "Astute"-class programme began in February 1986 when the Ministry of Defence (MOD) launched a number of studies intended to determine the capabilities and requirements for the replacement of its "Swiftsure" and "Trafalgar"-class fleet submarines. These studies, called project SSN20, were conducted during the Cold War, when the Royal Navy maintained a strong emphasis on anti-submarine warfare to counter increasingly more capable Soviet submarines. To match this growing threat, the studies concluded that project SSN20 should be a revolutionary design, with significantly enhanced nuclear propulsion and firepower, and a more sophisticated "integrated sonar suite" and combat systems. Similarly, the United States Navy, which was facing the same threats, went on to design and build the . The estimated costs of project SSN20, although great, were not considered a "constraint".


title: Astute-class submarine

text: However, by 1990 the Berlin Wall had fallen and the Cold War came to an end. Project SSN20 was promptly cancelled and a new set of design studies were started, this time, with "cost control" as a key objective. The "Trafalgar" class had been an evolved derivative of the preceding "Swiftsure" class, and in order to reduce cost and technical risk it was concluded that this new class of fleet submarine should "build upon" the "Trafalgar" design. This became known as the Batch 2 "Trafalgar" class (B2TC), with approval for the studies phase given in June 1991. While the philosophy behind B2TC was that of a modern and improved "Trafalgar", early design concepts of B2TC were also heavily influenced by the then under construction , in particular its nuclear steam raising plant (NSRP).


title: Astute-class submarine

text: Following two years of a studies phase on B2TC, the MOD decided to put the contract out to tender. A draft invitation to tender was announced in October 1993 and a final invitation to tender in July 1994. The final invitation to tender involved a formal competition between GEC-Marconi/BMT Limited and VSEL/Rolls-Royce, with bids to be submitted in June 1995. GEC-Marconi and BMT had little experience with British submarine designs, whereas VSEL and Rolls-Royce were heavily involved in both British nuclear submarine design and construction.


title: Astute-class submarine

text: During the assessment phase of the bids put forward by both teams, the MOD favoured the GEC-Marconi/BMT design on both cost and capability grounds. The bid put forward by VSEL/Rolls-Royce was less attractive and considered "an expensive and dull design." In June 1995, VSEL was subject to a takeover by GEC-Marconi, and with it, the Barrow shipyard. In December of the same year, the MOD announced that GEC-Marconi was the preferred bidder. The bid put forward by GEC-Marconi included the innovative use of 3D CAD software and modular construction techniques. Although the MOD had awarded the contract to GEC-Marconi, partly due to its competitive cost, it was still considered too high for the MOD to sign off on. The MOD and GEC-Marconi negotiated on a new price for the contract, amounting to £2.4 billion for the first three "Astute" submarines, plus in service support. The contract was signed on 14 March 1997, for what was now called the "Astute" programme, with a fixed maximum price, and any cost overruns being assumed by GEC-Marconi, the contractor.


title: Astute-class submarine

text: Although B2TC was intended to be a modest improvement over the "Trafalgar" class, it was not to be the case for "Astute". With the signing of the contract in March 1997, GEC-Marconi started work on developing a complete and comprehensive design for the "Astute" programme. Initial realisation was that the size of the Rolls-Royce PWR2 required a much larger boat (beam and length) and significantly improved acoustic quieting. A new understanding was reached between the MOD and GEC-Marconi that this would be an entirely new class, and far more complex than originally envisioned.


title: Astute-class submarine

text: In November 1999, British Aerospace purchased GEC-Marconi and created BAE Systems. At the time of the takeover, it had been approximately 20 years since the "Vanguard" class were designed, and the last of the boats had already been launched. The workforce at the Barrow shipyard had fallen from around 13,000, to 3,000. Key skills in design and engineering had been lost, predominantly through retirement or movement into other careers. This created significant delays and challenges in getting the "Astute" programme from design phase and into construction phase. Further delays and cost increases were also caused by the 3D CAD software, despite originally being touted as an innovative cost saving measure, by greatly reducing man-hours. However, one of the reasons for this was a lack of experienced designers able to use the software and its expanded tools.


title: Astute-class submarine

text: Despite numerous difficulties, including incomplete design drawings, the first boat, "Astute", was laid down on 31 January 2001. As planned, modular construction methods were used, with the boat being built in several ring-like modules, each up to several metres in length. These were welded together using specially designed high-strength steel, and then fitted out. From boat 2 onward however, vertical outfitting has been used, whereby the ring-like sections are "stood up on their ends." This has better enabled the fitting of large and heavy equipment, and has also proved to be more efficient, with reportedly "thousands of man-hours saved". The class is the first nuclear submarine to be designed entirely using 3D computer software.


title: Astute-class submarine

text: By 2002 both BAE and the MOD recognised they had underestimated the technical challenges and costs of the programme. In August 2002 the programme was estimated to be over three years late and hundreds of millions of pounds over budget. BAE Systems issued a profit warning on 11 December 2002 as a result of the cost overruns and delays. BAE Systems and the MOD subsequently renegotiated the contract, with an understanding that the MOD had to share some of the financial risks. In December 2003 the contract modifications were signed, with the MOD agreeing to add another £430 million to the programme and BAE Systems assuming £250 million of the cost overruns. The MOD also enlisted the advice and expertise of General Dynamics Electric Boat through a U.S. Navy contract. Eventually, a General Dynamics Electric Boat employee became the Astute Project Director at Barrow.