The W54 (also known as the Mark 54 or B54 ) was a tactical nuclear warhead developed by the United States in the late 1950s. The weapon is notable for being the smallest nuclear weapon in both weight and yield to have entered US service. It was a compact implosion device containing plutonium-239 as its fissile material, and in its various versions and mods it had a yield of 10 to 1,000 tons of TNT (42 to 4,184 gigajoules ).
76-475: W72 may refer to: W72 (nuclear warhead) Horonobe Station , in Hokkaido, Japan Small dodecicosidodecahedron W72, a Pontiac V8 engine Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title W72 . If an internal link led you here, you may wish to change the link to point directly to
152-424: A glass with no true melting point, can be used as a glass fiber for fiberglass but has the drawback that it must be worked at very high temperatures. In order to lower the necessary work temperature, other materials are introduced as "fluxing agents" (i.e., components to lower the melting point). Ordinary A-glass ("A" for "alkali-lime") or soda lime glass, crushed and ready to be remelted, as so-called cullet glass,
228-499: A 40-pound (18 kg) section of the weapon. It was felt that the XW-54 SADM proposal could produce a weapon of 11.875 inches (301.6 mm) diameter, 17.5 inches (440 mm) long and a weight of 56 pounds (25 kg) including carrying case. The weapon would also have a waterproof housing, have a pack for carrying in the field and a shock-mitigating container for parachute delivery. Development began June 1960. Because much of
304-556: A 5 mg/m total limit. As of 2001, the Hazardous Substances Ordinance in Germany dictates a maximum occupational exposure limit of 86 mg/m . In certain concentrations, a potentially explosive mixture may occur. Further manufacture of GRP components (grinding, cutting, sawing) creates fine dust and chips containing glass filaments, as well as tacky dust, in quantities high enough to affect health and
380-621: A November, 2011 modification to its Proposition 65 listing to include only "Glass wool fibers (inhalable and biopersistent)." Therefore a cancer warning label for biosoluble fiber glass home and building insulation is no longer required under federal or California law. As of 2012, the North American Insulation Manufacturers Association stated that fiberglass is safe to manufacture, install and use when recommended work practices are followed to reduce temporary mechanical irritation. As of 2012,
456-439: A binder. It is typically processed using the hand lay-up technique, where sheets of material are placed on a mold and brushed with resin. Because the binder dissolves in resin, the material easily conforms to different shapes when wetted out. After the resin cures, the hardened product can be taken from the mold and finished. Using chopped strand mat gives the fiberglass isotropic in-plane material properties. A coating or primer
532-417: A chemical solution. The individual filaments are now bundled in large numbers to provide a roving . The diameter of the filaments, and the number of filaments in the roving, determine its weight , typically expressed in one of two measurement systems: These rovings are then either used directly in a composite application such as pultrusion , filament winding (pipe), gun roving (where an automated gun chops
608-401: A combined stream from a chopper gun. Workers roll out the spray-up to compact the laminate. Wood, foam or other core material may then be added, and a secondary spray-up layer imbeds the core between the laminates. The part is then cured, cooled, and removed from the reusable mold. Pultrusion is a manufacturing method used to make strong, lightweight composite materials. In pultrusion, material
684-430: A liner to prevent gas leakage or as a barrier to protect the composite from the fluid to be stored. Filament winding is well suited to automation, and there are many applications, such as pipe and small pressure vessels that are wound and cured without any human intervention. The controlled variables for winding are fiber type, resin content, wind angle, tow or bandwidth and thickness of the fiber bundle. The angle at which
760-936: A post-exposure recovery period." Historic reviews of the epidemiology studies had been conducted by Harvard's Medical and Public Health Schools in 1995, the National Academy of Sciences in 2000, the Agency for Toxic Substances and Disease Registry ("ATSDR") in 2004, and the National Toxicology Program in 2011. which reached the same conclusion as IARC that there is no evidence of increased risk from occupational exposure to glass wool fibers. Genetic and toxic effects are exerted through production of reactive oxygen species , which can damage DNA, and cause chromosomal aberrations , nuclear abnormalities, mutations, gene amplification in proto-oncogenes , and cell transformation in mammalian cells. There
836-504: A radar based fuze set for a 40 feet (12 m) airburst and a capacitance based fuze set for 2 feet (0.61 m) airburst. These fuzes represented the high and low airburst modes of the weapon. The device contained 26 pounds (12 kg) of high explosives. Some sources give the yield for the Mod 0 as 250 tons of TNT (1,000 GJ) and the Mod 2 as 10 to 20 tons of TNT (42 to 84 GJ), but declassified warhead development documents indicate
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#1732775884234912-480: A stationary 155-millimeter launcher and set to detonate low airburst 1.7 miles (2.7 km) from the launch point. This test was the last atmospheric test at Nevada Test Site and was performed in conjunction with Operation Ivy Flats, a simulated military environment. It was observed by Attorney General Robert F. Kennedy and presidential adviser General Maxwell D. Taylor . Fiberglass Fiberglass ( American English ) or fibreglass ( Commonwealth English )
988-415: A thermoplastic inner tank which acts as a preform during construction. Much more reliable tanks are made using woven mat or filament wound fiber, with the fiber orientation at right angles to the hoop stress imposed in the sidewall by the contents. Such tanks tend to be used for chemical storage because the plastic liner (often polypropylene ) is resistant to a wide range of corrosive chemicals. Fiberglass
1064-473: A yield of around 600 tons of TNT. The 300 W72 units were produced between 1970 and 1972 and were in service until 1979. Stockpiled W54 warheads were test-fired at the Nevada Test Site on July 7 and July 17, 1962. In Little Feller II (July 7), the warhead was suspended 3 feet (0.91 m) above the ground. In Little Feller I (July 17), the warhead was launched as a Davy Crockett device from
1140-422: Is a common type of fiber-reinforced plastic using glass fiber . The fibers may be randomly arranged, flattened into a sheet called a chopped strand mat, or woven into glass cloth . The plastic matrix may be a thermoset polymer matrix —most often based on thermosetting polymers such as epoxy , polyester resin , or vinyl ester resin —or a thermoplastic . Cheaper and more flexible than carbon fiber , it
1216-427: Is a fabrication technique mainly used for manufacturing open (cylinders) or closed-end structures (pressure vessels or tanks). The process involves winding filaments under tension over a male mandrel. The mandrel rotates while a wind eye on a carriage moves horizontally, laying down fibers in the desired pattern. The most common filaments are carbon or glass fiber and are coated with synthetic resin as they are wound. Once
1292-551: Is also indirect, inflammation-driven genotoxicity through reactive oxygen species by inflammatory cells . The longer and thinner as well as the more durable (biopersistent) fibers were, the more potent they were in damage. In the US, fine mineral fiber emissions have been regulated by the EPA , but respirable fibers (“particulates not otherwise regulated”) are regulated by Occupational Safety and Health Administration (OSHA); OSHA has set
1368-432: Is also used for septic tanks . Glass-reinforced plastics are also used to produce house building components such as roofing laminate, door surrounds, over-door canopies, window canopies and dormers, chimneys, coping systems, and heads with keystones and sills. The material's reduced weight and easier handling, compared to wood or metal, allows faster installation. Mass-produced fiberglass brick-effect panels can be used in
1444-401: Is applied to the chosen mold to allow the finished product to be cleanly removed from the mold. Resin—typically a 2-part thermoset polyester, vinyl, or epoxy—is mixed with its hardener and applied to the surface. Sheets of fiberglass matting are laid into the mold, then more resin mixture is added using a brush or roller. The material must conform to the mold, and air must not be trapped between
1520-479: Is applied to the roving to help protect the glass filaments for processing and manipulation and to ensure proper bonding to the resin matrix, thus allowing for the transfer of shear loads from the glass fibers to the thermoset plastic. Without this bonding, the fibers can 'slip' in the matrix causing localized failure. An individual structural glass fiber is both stiff and strong in tension and compression —that is, along its axis. Although it might be assumed that
1596-483: Is called pultrusion . The manufacturing process for glass fibers suitable for reinforcement uses large furnaces to gradually melt the silica sand, limestone , kaolin clay , fluorspar , colemanite , dolomite and other minerals until a liquid forms. It is then extruded through bushings ( spinneret ), which are bundles of very small orifices (typically 5–25 micrometres in diameter for E-Glass, 9 micrometres for S-Glass). These filaments are then sized (coated) with
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#17327758842341672-592: Is credited with producing the first composite boat in 1937 but did not proceed further at the time because of the brittle nature of the plastic used. In 1939 Russia was reported to have constructed a passenger boat of plastic materials, and the United States a fuselage and wings of an aircraft. The first car to have a fiberglass body was a 1946 prototype of the Stout Scarab , but the model did not enter production. Unlike glass fibers used for insulation, for
1748-401: Is essentially an entire two-dimensional plane; with woven fabrics or unidirectional layers, directionality of stiffness and strength can be more precisely controlled within the plane. A fiberglass component is typically of a thin "shell" construction, sometimes filled on the inside with structural foam, as in the case of surfboards. The component may be of nearly arbitrary shape, limited only by
1824-513: Is pulled through forming machinery using either a hand-over-hand method or a continuous-roller method (as opposed to extrusion , where the material is pushed through dies). In fiberglass pultrusion, fibers (the glass material) are pulled from spools through a device that coats them with a resin. They are then typically heat-treated and cut to length. Fiberglass produced this way can be made in a variety of shapes and cross-sections, such as W or S cross-sections. People can be exposed to fiberglass in
1900-639: Is required, such as equipment cabinets and steel support structures, due to the ease with which it can be molded and painted to blend with existing structures and surfaces. Other uses include sheet-form electrical insulators and structural components commonly found in power-industry products. Because of fiberglass's lightweight and durability, it is often used in protective equipment such as helmets. Many sports use fiberglass protective gear, such as goaltenders' and catchers' masks. Storage tanks can be made of fiberglass with capacities up to about 300 tonnes . Smaller tanks can be made with chopped strand mat cast over
1976-510: Is sometimes referred to as "fiberglass", the composite is also called fiberglass-reinforced plastic ( FRP ). This article uses "fiberglass" to refer to the complete fiber-reinforced composite material, rather than only to the glass fiber within it. Glass fibers have been produced for centuries, but the earliest patent was awarded to the Prussian inventor Hermann Hammesfahr (1845–1914) in the U.S. in 1880. Mass production of glass strands
2052-635: Is stronger than many metals by weight, non- magnetic , non- conductive , transparent to electromagnetic radiation , can be molded into complex shapes, and is chemically inert under many circumstances. Applications include aircraft, boats, automobiles, bath tubs and enclosures, swimming pools , hot tubs , septic tanks , water tanks , roofing, pipes, cladding, orthopedic casts , surfboards , and external door skins. Other common names for fiberglass are glass-reinforced plastic ( GRP ), glass-fiber reinforced plastic ( GFRP ) or GFK (from German : Glasfaserverstärkter Kunststoff ). Because glass fiber itself
2128-402: Is that the resins used are subject to contraction during the curing process. For polyester this contraction is often 5–6%; for epoxy, about 2%. Because the fibers do not contract, this differential can create changes in the shape of the part during curing. Distortions can appear hours, days, or weeks after the resin has set. While this distortion can be minimized by symmetric use of the fibers in
2204-464: Is used when tensile strength (high modulus) is important and is thus an important building and aircraft epoxy composite (it is called R-glass, "R" for "reinforcement" in Europe). C-glass ("C" for "chemical resistance") and T-glass ("T" is for "thermal insulator"—a North American variant of C-glass) are resistant to chemical attack; both are often found in insulation-grades of blown fiberglass. Fiberglass
2280-433: Is versatile because it is lightweight, strong, weather-resistant, and can have a variety of surface textures. During World War II, fiberglass was developed as a replacement for the molded plywood used in aircraft radomes (fiberglass being transparent to microwaves ). Its first main civilian application was for the building of boats and sports car bodies, where it gained acceptance in the 1950s. Its use has broadened to
2356-622: The B54-0 ) was put into production in April 1963. Drop tests for this weapon were conducted at velocities up to 31 feet per second (9.4 m/s) vertical and 17 feet per second (5.2 m/s) horizontal without damage. Production of the B54 Mod 1 SADM began in August 1964. The weapon was 12 inches (305 mm) diameter, 18 inches (457 mm) long and weighed 58.5 pounds (26.5 kg), and included
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2432-651: The Davy Crockett recoilless gun , and another used in the Special Atomic Demolition Munition (SADM) system, along with several mods for each version. The two types are distinct in that much of the design between them was different, to the point that during the development of the SADM it was proposed that it be given its own unique mark designation. A later development was the W72 , which
2508-573: The International Agency for Research on Cancer (IARC) as "not classifiable as to carcinogenicity to humans" ( IARC group 3 ). "Epidemiologic studies published during the 15 years since the previous IARC monographs review of these fibers in 1988 provide no evidence of increased risks of lung cancer or mesothelioma (cancer of the lining of the body cavities) from occupational exposures during the manufacture of these materials, and inadequate evidence overall of any cancer risk." In June 2011,
2584-457: The M-388 when configured into a Davy Crockett round. Three mods of the SADM configuration were developed: B54 Mod 0 – Interim weapon with timer issues. B54 Mod 1 – Production weapon. Came with special housing for underwater use. B54 Mod 2 – Weapon weight increased from 58.5 pounds (26.5 kg) to 70 pounds (32 kg). May be a boosted weapon. In service, the weapons were known as
2660-752: The Special Atomic Demolition Munition (SADM) began in February 1958 when the Army desired a new munition that could be carried by one man. The project was delayed by the needs of the Falcon and Davy Crockett application until November 1959. The proposal noted that the existing atomic demolition munition (ADM), the T-4 Atomic Demolition Munition , was based on the Mark 9 gun-type artillery shell and that transport required four men, each carrying
2736-732: The XM129 and XM159 Atomic Demolition Charges . Which versions are associated with the XM129 name and which is associated with the XM159 name is not clear. After the AIM-26 Falcon was retired, 300 units were rebuilt into an improved configuration with a higher yield and redesignated the W72 . These warheads were then used to produce a number of nuclear versions of the AGM-62 Walleye television-guided glide bomb system. The W72 variant had
2812-679: The XW-54 . For both the Falcon and Davy Crockett, the Department of Defense would supply the weapon systems and adaptation kits for the warheads, while the warheads and firing systems would be the responsibility of the Atomic Energy Commission . First production date for the Falcon warhead was planned for February 1961 while the warhead for the Davy Crockett was given a planned first production date of October 1961. This
2888-555: The European Union and Germany have classified synthetic glass fibers as possibly or probably carcinogenic, but fibers can be exempt from this classification if they pass specific tests. A 2012 health hazard review for the European Commission stated that inhalation of fiberglass at concentrations of 3, 16 and 30 mg/m3 "did not induce fibrosis nor tumours except transient lung inflammation that disappeared after
2964-573: The US National Toxicology Program (NTP) removed from its Report on Carcinogens all biosoluble glass wool used in home and building insulation and for non-insulation products. However, NTP still considers fibrous glass dust to be "reasonably anticipated [as] a human carcinogen (Certain Glass Wool Fibers (Inhalable))". Similarly, California's Office of Environmental Health Hazard Assessment (OEHHA) published
3040-564: The XW-54-X1 for the Davy Crockett (now called the Mk 54 Mod 2 ) was achieved in April 1961. Both the Mod 0 and Mod 2 weapons were interchangeable by changing the environmental sensing device. The final weapon was 10.862 inches (275.9 mm) in diameter, 15.716 inches (399.2 mm) in length and 50.9 pounds (23.1 kg) in weight, and was packaged in a fiberglass housing coated in a conductive lacquer to provide an electrical shield. Interest in
3116-518: The adaptation kit would disable the weapon's safeties. The Department of Defense cancelled the requirement for the XW-54-X2 (now called the Mk 54 Mod 1 ) in July 1960 after parts manufacturing slippage delayed production of the warhead. This also caused the accelerated schedule for the Falcon application to slip to January 1961. Production of both the Falcon warhead (now called the Mk 54 Mod 0 ) and
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3192-458: The air near manufacturing facilities or when they are near building fires or implosions . The American Lung Association advises that fiberglass insulation should never be left exposed in an occupied area. Since work practices are not always followed, and fiberglass is often left exposed in basements that later become occupied, people can get exposed. No readily usable biological or clinical indices of exposure exist. Fiberglass will irritate
3268-599: The automotive and sport equipment sectors. In the production of some products, such as aircraft, carbon fiber is now used instead of fiberglass, which is stronger by volume and weight. Advanced manufacturing techniques such as pre-pregs and fiber rovings extend fiberglass's applications and the tensile strength possible with fiber-reinforced plastics. Fiberglass is also used in the telecommunications industry for shrouding antennas , due to its RF permeability and low signal attenuation properties. It may also be used to conceal other equipment where no signal permeability
3344-550: The complexity and tolerances of the mold used for manufacturing the shell. The mechanical functionality of materials is heavily reliant on the combined performances of both the resin (AKA matrix) and fibers. For example, in severe temperature conditions (over 180 °C), the resin component of the composite may lose its functionality, partially due to bond deterioration of resin and fiber. However, GFRPs can still show significant residual strength after experiencing high temperatures (200 °C). One notable feature of fiberglass
3420-412: The construction of composite housing, and can include insulation to reduce heat loss. In rod pumping applications, fiberglass rods are often used for their high tensile strength to weight ratio. Fiberglass rods provide an advantage over steel rods because they stretch more elastically (lower Young's modulus ) than steel for a given weight, meaning more oil can be lifted from the hydrocarbon reservoir to
3496-973: The design, a certain amount of internal stress is created; and if it becomes too great, cracks form. The most common types of glass fiber used in fiberglass is E-glass , which is alumino-borosilicate glass with less than 1% w/w alkali oxides, mainly used for glass-reinforced plastics. Other types of glass used are A-glass ( A lkali-lime glass with little or no boron oxide), E-CR-glass ( E lectrical/ C hemical R esistance; alumino-lime silicate with less than 1% w/w alkali oxides, with high acid resistance), C-glass (alkali-lime glass with high boron oxide content, used for glass staple fibers and insulation), D-glass (borosilicate glass, named for its low D ielectric constant), R-glass (alumino silicate glass without MgO and CaO with high mechanical requirements as R einforcement), and S-glass (alumino silicate glass without CaO but with high MgO content with high tensile strength). Pure silica (silicon dioxide), when cooled as fused quartz into
3572-433: The early 1940s, and many sailing vessels made after 1950 were built using the fiberglass lay-up process . As of 2022, boats continue to be made with fiberglass, though more advanced techniques such as vacuum bag moulding are used in the construction process. Though most bullet-resistant armours are made using different textiles, fiberglass composites have been shown to be effective as ballistic armor. Filament winding
3648-562: The eyes, skin, and the respiratory system. Hence, symptoms can include itchy eyes, skin, nose, sore throat, hoarseness, dyspnea (breathing difficulty) and cough. Peak alveolar deposition was observed in rodents and humans for fibers with diameters of 1 to 2 μm. In animal experiments, adverse lung effects such as lung inflammation and lung fibrosis have occurred, and increased incidences of mesothelioma , pleural sarcoma , and lung carcinoma had been found with intrapleural or intratracheal instillations in rats. As of 2001, in humans only
3724-563: The fiber has an effect on the properties of the final product. A high angle "hoop" will provide circumferential or "burst" strength, while lower angle patterns (polar or helical) will provide greater longitudinal tensile strength. Products currently being produced using this technique range from pipes, golf clubs, Reverse Osmosis Membrane Housings, oars, bicycle forks, bicycle rims, power and transmission poles, pressure vessels to missile casings, aircraft fuselages and lamp posts and yacht masts. A release agent, usually in either wax or liquid form,
3800-434: The fiber is weak in compression, it is actually only the long aspect ratio of the fiber which makes it seem so; i.e., because a typical fiber is long and narrow, it buckles easily. On the other hand, the glass fiber is weak in shear—that is, across its axis. Therefore, if a collection of fibers can be arranged permanently in a preferred direction within a material, and if they can be prevented from buckling in compression,
3876-415: The fiberglass and the mold. Additional resin is applied and possibly additional sheets of fiberglass. Hand pressure, vacuum or rollers are used to be sure the resin saturates and fully wets all layers, and that any air pockets are removed. The work must be done quickly before the resin starts to cure unless high-temperature resins are used which will not cure until the part is warmed in an oven. In some cases,
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#17327758842343952-420: The final structure to be strong, the fiber's surfaces must be almost entirely free of defects, as this permits the fibers to reach gigapascal tensile strengths . If a bulk piece of glass were defect-free, it would be as strong as glass fibers; however, it is generally impractical to produce and maintain bulk material in a defect-free state outside of laboratory conditions. The process of manufacturing fiberglass
4028-459: The gas content of the material was replaced by plastic. This reduced the insulation properties to values typical of the plastic, but now for the first time, the composite showed great strength and promise as a structural and building material. Many glass fiber composites continued to be called "fiberglass" (as a generic name) and the name was also used for the low-density glass wool product containing gas instead of plastic. Ray Greene of Owens Corning
4104-473: The glass into short lengths and drops it into a jet of resin, projected onto the surface of a mold), or in an intermediary step, to manufacture fabrics such as chopped strand mat (CSM) (made of randomly oriented small cut lengths of fiber all bonded together), woven fabrics, knit fabrics or unidirectional fabrics. Chopped strand mat (CSM) is a form of reinforcement used in fiberglass. It consists of glass fibers laid randomly across each other and held together by
4180-566: The greater priority, an interim environmental sensing device could be developed. The Air Force subsequently accelerated the availability date for the Falcon missile and Sandia design released the warhead without an environmental sensing device in October 1959. However, revisions were issued in December before warhead production began with a suitable environmental sensing device for Falcon use. A single environmental sensing device for both systems
4256-500: The intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=W72&oldid=1176775735 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages W72 (nuclear warhead) The weapon had two distinct versions: a warhead used in the AIM-26 Falcon air-to-air missile and in
4332-441: The legal limit ( permissible exposure limit ) for fiberglass exposure in the workplace as 15 mg/m total and 5 mg/m in respiratory exposure over an 8-hour workday. The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of 3 fibers/cm (less than 3.5 micrometers in diameter and greater than 10 micrometers in length) as a time-weighted average over an 8-hour workday, and
4408-413: The mandrel is completely covered to the desired thickness, the resin is cured; often the mandrel is placed in an oven to achieve this, though sometimes radiant heaters are used with the mandrel still turning in the machine. Once the resin has cured, the mandrel is removed, leaving the hollow final product. For some products such as gas bottles, the 'mandrel' is a permanent part of the finished product forming
4484-449: The material will be preferentially strong in that direction. Furthermore, by laying multiple layers of fiber on top of one another, with each layer oriented in various preferred directions, the material's overall stiffness and strength can be efficiently controlled. In fiberglass, it is the plastic matrix which permanently constrains the structural glass fibers to directions chosen by the designer. With chopped strand mat, this directionality
4560-586: The more biopersistent materials like ceramic fibres, which are used industrially as insulation in high-temperature environments such as blast furnaces , and certain special-purpose glass wools not used as insulating materials remain classified as possible carcinogens ( IARC Group 2B ). The more commonly used glass fibre wools including insulation glass wool , rock wool and slag wool are considered not classifiable as to carcinogenicity to humans ( IARC Group 3 ). In October 2001, all fiberglass wools commonly used for thermal and acoustical insulation were reclassified by
4636-586: The only difference between these two warheads was the environmental sensing devices used and that the warheads were field convertible, suggesting the weapons had the same yield. Official documents give the yield as 20 tonnes of TNT (84 GJ) when configured in the XM388 round for the Davy Crockett. It has been alleged that the British "Wee Gwen" warhead was a copy of the W54. Though never put into production, Wee Gwen
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#17327758842344712-628: The surface with each stroke, all while reducing the load on the pumping unit. Fiberglass rods must be kept in tension, however, as they frequently part if placed in even a small amount of compression. The buoyancy of the rods within a fluid amplifies this tendency. GRP and GRE pipe can be used in a variety of above- and below-ground systems, including those for desalination, water treatment, water distribution networks, chemical process plants, water used for firefighting, hot and cold drinking water, wastewater/sewage, municipal waste and liquified petroleum gas . Fiberglass composite boats have been made since
4788-446: The warhead and SADM weapon. Weapons of the same mod number but in different applications are not the same weapons. Three mods of the warhead configuration were developed: W54 Mod 0 – Warhead for AIM-4 Falcon air-to-air missile W54 Mod 1 – Interim warhead for Davy Crockett. Lacked environmental sensing device. Never entered production. W54 Mod 2 – Production Davy Crockett warhead with environmental sensing device. Was known as
4864-523: The warhead, fuzing and firing system with a mechanical timer, ferroelectric firing set and a sealed housing. The body was constructed with aluminium forgings and moulded fibreglass, and foam-rubber insulation was used between the warhead and case. Dials were illuminated with a tritium-phosphor paint for easy night-reading. A housing for underwater emplacement was provided which included external controls. The B54 Mod 2 started production in June 1965. The weapon
4940-557: The weapon would be different from the XW-54 warhead, it was proposed that the warhead be given its own unique mark designation, such as TX-58 (later used for the Polaris A-3 warhead ), but the decision was made to retain the existing mark number. The weapon was delayed until August 1963 due to issues with the timer. These included premature firing of the timer and issues with bearing materials. An interim Mk 54 Mod 0 weapon (now called
5016-482: The work is covered with plastic sheets and vacuum is drawn on the work to remove air bubbles and press the fiberglass to the shape of the mold. The fiberglass spray lay-up process is similar to the hand lay-up process but differs in the application of the fiber and resin to the mold. Spray-up is an open-molding composites fabrication process where resin and reinforcements are sprayed onto a mold. The resin and glass may be applied separately or simultaneously "chopped" in
5092-415: The workplace during its fabrication, installation or removal, by breathing it in, by skin contact, or by eye contact. Furthermore, in the manufacturing process of fiberglass, styrene vapors are released while the resins are cured. These are also irritating to mucous membranes and respiratory tract. The general population can get exposed to fibreglass from insulation and building materials or from fibers in
5168-495: Was accidentally discovered in 1932 when Games Slayter , a researcher at Owens-Illinois , directed a jet of compressed air at a stream of molten glass and produced fibers. A patent for this method of producing glass wool was first applied for in 1933. Owens joined with the Corning company in 1935 and the method was adapted by Owens Corning to produce its patented "Fiberglas" (spelled with one "s") in 1936. Originally, Fiberglas
5244-425: Was a glass wool with fibers entrapping a great deal of gas, making it useful as an insulator, especially at high temperatures. A suitable resin for combining the fiberglass with a plastic to produce a composite material was developed in 1936 by DuPont . The first ancestor of modern polyester resins is Cyanamid 's resin of 1942. Peroxide curing systems were used by then. With the combination of fiberglass and resin
5320-611: Was a rebuilt W54 used with the AGM-62 Walleye guided bomb . The W72 was in service until 1979. Interest in a lightweight, low-yield weapon for the Falcon and Davy Crockett began in 1958. The weapon was initially developed by the University of California Radiation Laboratory at Livermore under the XW-51 designation, but in January 1959 the development of the weapon was transferred to Los Alamos National Laboratory and redesignated
5396-454: Was abandoned at this time and development on the XW-54-X1 and XW-54-X2 for Davy Crockett use began. The XW-54-X2 warhead would lack any environmental sensing device for initial deployment, while the XW-54-X1 fitted with a suitable environmental sensing device would replace the XW-54-X2 as the weapon became available. Sandia were against the development of the XW-54-X2 as simply disconnecting
5472-444: Was because it was felt that the higher acceleration experienced by the warhead in Davy Crockett service would make certification of parts more challenging. It was hoped during development that the same warhead for both applications could be used, but the requirements for the environmental sensing device - used to detect if the weapon was in its correct military environment and in turn disable weapon safing devices - for each application
5548-506: Was quite different. In Falcon use, the warhead experienced 17 g (170 m/s ) of acceleration for 0.8 seconds while in Davy Crockett use the weapon experienced 1,800 to 2,500 g (18,000 to 25,000 m/s ) for 3 milliseconds. The envisioned device was one that would not actuate under less than 10 g (98 m/s ) or under less than 2 g per second (20 m/s /s). Sandia reported the problem in May 1959, stating that if Falcon warheads had
5624-443: Was the first type of glass used for fiberglass. E-glass ("E" because of initial Electrical application), is alkali-free and was the first glass formulation used for continuous filament formation. It now makes up most of the fiberglass production in the world, and also is the single largest consumer of boron minerals globally. It is susceptible to chloride ion attack and is a poor choice for marine applications. S-glass ("S" for "stiff")
5700-501: Was the same size as previous mods, but now weighed 70 pounds (32 kg). This may be the highest yield boosted version of the weapon. The weapon was based on the Scarab device, which descended from the Gnat device. Scarab was also used as a primary stage in the thermonuclear weapon test Dominic Nambe . Configured in the Davy Crockett role, the weapon contained two sets of fuzes:
5776-507: Was to contain 1.6 kilograms (3.5 lb) of plutonium and 2.42 kilograms (5.3 lb) uranium. Yield is estimated to be 10 to 1,000 tons of TNT (42 to 4,184 GJ). The B54 SADM included a Field Wire Remote Control System (FWRCS), a device that enabled the sending of safe/arm and firing signals to the weapon via a wire for safe remote detonation of the weapon by troops. This system was tested for its resistance to electromagnetic radiation in February 1964. W54 mod numbers overlap between
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