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62-679: The DOT-117 ( TC-117 in Canada) is a type of unpressurized tank car in use on North American railroads. The DOT-117 design was developed in the aftermath of the Lac-Mégantic rail disaster of 2013 in an effort to upgrade the specifications of the then-common DOT-111 and CPC-1232 designs. It was announced on May 1, 2015 by the United States Federal Railroad Administration (FRA) and Canada's Transport Canada (TC). The specifications require that

124-605: A BLEVE . DOT-114 tank cars are used in North America to carry pressurized gases. A milk car is a specialized type of tank car designed to carry raw milk between farms, creameries , and processing plants. Milk is now commonly chilled, before loading, and transported in a glass-lined tank car. Such tank cars are often placarded as "Food service use only". Tank cars of this type are designed to carry cryogenic liquid Hydrogen (LH 2 ). North American cars are classified as DOT113, AAR204W, and AAR204XT A pickle car

186-408: A cryogenic air separation unit; a process that separates liquid nitrogen , which boils at 77.3 K, from argon, which boils at 87.3 K, and liquid oxygen , which boils at 90.2 K. About 700,000 tonnes of argon are produced worldwide every year. Argon has several desirable properties: Other noble gases would be equally suitable for most of these applications, but argon is by far

248-588: A dry suit because it is inert and has low thermal conductivity. Argon is used as a propellant in the development of the Variable Specific Impulse Magnetoplasma Rocket (VASIMR). Compressed argon gas is allowed to expand, to cool the seeker heads of some versions of the AIM-9 Sidewinder missile and other missiles that use cooled thermal seeker heads. The gas is stored at high pressure . Argon-39, with

310-414: A half-life of 1.25 × 10 years, decays to stable Ar (11.2%) by electron capture or positron emission , and also to stable Ca (88.8%) by beta decay . These properties and ratios are used to determine the age of rocks by K–Ar dating . In Earth's atmosphere, Ar is made by cosmic ray activity, primarily by neutron capture of Ar followed by two-neutron emission. In

372-437: A time projection chamber for fine grained three-dimensional imaging of neutrino interactions. At Linköping University, Sweden, the inert gas is being utilized in a vacuum chamber in which plasma is introduced to ionize metallic films. This process results in a film usable for manufacturing computer processors. The new process would eliminate the need for chemical baths and use of expensive, dangerous and rare materials. Argon

434-402: A torpedo . A vinegar car is a specialized type of tank car designed to transport vinegar . The largest such car built was built by Morrison Railway Supply Corporation in 1968. The car's underframe included all of the modern facets of freight car design including roller bearing trucks and cushioning devices built by FreightMaster, while the tank that rode on it, made of Douglas fir , had

496-558: A capacity of 17,100 US gallons (65 m ; 14,200 imp gal). The car, in what has been called 'the largest wooden tank car ever built', took 18 months to build. The Reinhart Vinegar Car can be seen at the Toronto Harbourfront Museum . Vinegar is now moved in ordinary tank cars lined with glass, plastic, or alloy steel . In the early 1960s, the Union Tank Car Company introduced

558-647: A container for storage. Since 2002, the American National Archives stores important national documents such as the Declaration of Independence and the Constitution within argon-filled cases to inhibit their degradation. Argon is preferable to the helium that had been used in the preceding five decades, because helium gas escapes through the intermolecular pores in most containers and must be regularly replaced. Argon may be used as

620-559: A distinct scintillation time profile, which allows the separation of electronic recoils from nuclear recoils. On the other hand, its intrinsic beta-ray background is larger due to Ar contamination, unless one uses argon from underground sources, which has much less Ar contamination. Most of the argon in Earth's atmosphere was produced by electron capture of long-lived K ( K + e → Ar + ν) present in natural potassium within Earth. The Ar activity in

682-413: A food product, and since it replaces oxygen within the dead bird, argon also enhances shelf life. Argon is sometimes used for extinguishing fires where valuable equipment may be damaged by water or foam. Liquid argon is used as the target for neutrino experiments and direct dark matter searches. The interaction between the hypothetical WIMPs and an argon nucleus produces scintillation light that

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744-486: A half-life of 269 years, has been used for a number of applications, primarily ice core and ground water dating. Also, potassium–argon dating and related argon-argon dating are used to date sedimentary , metamorphic , and igneous rocks . Argon has been used by athletes as a doping agent to simulate hypoxic conditions. In 2014, the World Anti-Doping Agency (WADA) added argon and xenon to

806-469: A lattice of water molecules. Ions , such as ArH , and excited-state complexes , such as ArF, have been demonstrated. Theoretical calculation predicts several more argon compounds that should be stable but have not yet been synthesized. Argon ( Greek ἀργόν , neuter singular form of ἀργός meaning "lazy" or "inactive") is named in reference to its chemical inactivity. This chemical property of this first noble gas to be discovered impressed

868-460: A mixture of atmospheric air with additional oxygen in a test-tube (A) upside-down over a large quantity of dilute alkali solution (B), which in Cavendish's original experiment was potassium hydroxide, and conveyed a current through wires insulated by U-shaped glass tubes (CC) which sealed around the platinum wire electrodes, leaving the ends of the wires (DD) exposed to the gas and insulated from

930-583: A series of "whale belly" tank cars which offered increased capacity. These cars carried from 33,000 US gallons (125 m ; 27,478 imp gal) in CSOX #31084 to as much as 63,000 US gallons (238 m ; 52,458 imp gal) in GATX #96500, which had been conceived as a 'rolling experiment'. The largest tank car ever placed into regular service, UTLX #83699 , was rated at 50,000 US gallons (189 m ; 41,634 imp gal). It entered service in 1963 and

992-423: Is 20 feet (6.10 m) long, 8 feet (2.44 m) high and 8 feet (2.44 m) wide. The tank, which is made from stainless steel, is held within a box-shaped frame with the same shape as an intermodal container . This allows it to be carried on multiple modes of transport, such as truck, rail and ship. A torpedo car or bottle car is a type of railroad car used in steel mills to haul molten pig iron from

1054-492: Is a defining fixed point in the International Temperature Scale of 1990 . Argon is extracted industrially by the fractional distillation of liquid air . It is mostly used as an inert shielding gas in welding and other high-temperature industrial processes where ordinarily unreactive substances become reactive; for example, an argon atmosphere is used in graphite electric furnaces to prevent

1116-428: Is also commonly used for sputter deposition of thin films as in microelectronics and for wafer cleaning in microfabrication . Cryosurgery procedures such as cryoablation use liquid argon to destroy tissue such as cancer cells. It is used in a procedure called "argon-enhanced coagulation", a form of argon plasma beam electrosurgery . The procedure carries a risk of producing gas embolism and has resulted in

1178-500: Is built to a US standard. The design has been criticized on safety grounds. The train in the Lac-Mégantic derailment of 2013 was made up of 72 of these cars. DOT-112 tank cars are used in North America to carry pressurized gases. One of these tank cars exploded in Waverley, TN, killing 16, when a Louisville & Nashville train derailed. While the clean up efforts were under way, the tank car, UTLX 83013, ended up exploding from

1240-538: Is chemically inert under most conditions and forms no confirmed stable compounds at room temperature. Although argon is a noble gas , it can form some compounds under various extreme conditions. Argon fluorohydride (HArF), a compound of argon with fluorine and hydrogen that is stable below 17 K (−256.1 °C; −429.1 °F), has been demonstrated. Although the neutral ground-state chemical compounds of argon are presently limited to HArF, argon can form clathrates with water when atoms of argon are trapped in

1302-458: Is detected by photomultiplier tubes . Two-phase detectors containing argon gas are used to detect the ionized electrons produced during the WIMP–nucleus scattering. As with most other liquefied noble gases, argon has a high scintillation light yield (about 51 photons/keV ), is transparent to its own scintillation light, and is relatively easy to purify. Compared to xenon , argon is cheaper and has

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1364-491: Is giving way to higher-capacity (longer), yet standard-width, AAR Plate "C" , cars. All tank cars undergo periodic inspection for damage and corrosion. Pressure relief valves are inspected at every loading. Pressurized cars are pressure-tested regularly to ensure the integrity of the tank. All tank cars operating throughout North America today feature AAR Type E double shelf couplers that are designed to prevent disengaging in event of an accident or derailment. This reduces

1426-495: Is inert and relatively cheap. Argon is used in some high-temperature industrial processes where ordinarily non-reactive substances become reactive. For example, an argon atmosphere is used in graphite electric furnaces to prevent the graphite from burning. For some of these processes, the presence of nitrogen or oxygen gases might cause defects within the material. Argon is used in some types of arc welding such as gas metal arc welding and gas tungsten arc welding , as well as in

1488-486: Is more than twice as abundant as water vapor (which averages about 4000 ppmv, but varies greatly), 23 times as abundant as carbon dioxide (400 ppmv), and more than 500 times as abundant as neon (18 ppmv). Argon is the most abundant noble gas in Earth's crust , comprising 0.00015% of the crust. Nearly all argon in Earth's atmosphere is radiogenic argon-40 , derived from the decay of potassium-40 in Earth's crust. In

1550-491: Is the primary industrial source of purified argon products. Argon is isolated from air by fractionation, most commonly by cryogenic fractional distillation , a process that also produces purified nitrogen , oxygen , neon , krypton and xenon . Earth's crust and seawater contain 1.2 ppm and 0.45 ppm of argon, respectively. The main isotopes of argon found on Earth are Ar (99.6%), Ar (0.34%), and Ar (0.06%). Naturally occurring K , with

1612-402: Is the reason the standard atomic weight of terrestrial argon is greater than that of the next element, potassium , a fact that was puzzling when argon was discovered. Mendeleev positioned the elements on his periodic table in order of atomic weight, but the inertness of argon suggested a placement before the reactive alkali metal . Henry Moseley later solved this problem by showing that

1674-440: Is used for the specific way it ionizes and emits light, such as in plasma globes and calorimetry in experimental particle physics . Gas-discharge lamps filled with pure argon provide lilac/violet light; with argon and some mercury, blue light. Argon is also used for blue and green argon-ion lasers . Argon is used for thermal insulation in energy-efficient windows . Argon is also used in technical scuba diving to inflate

1736-406: Is used in a variety of activities to provide a barrier against oxygen at the liquid surface, which can spoil wine by fueling both microbial metabolism (as with acetic acid bacteria ) and standard redox chemistry. Argon is sometimes used as the propellant in aerosol cans. Argon is also used as a preservative for such products as varnish , polyurethane , and paint, by displacing air to prepare

1798-457: Is used to displace oxygen- and moisture-containing air in packaging material to extend the shelf-lives of the contents (argon has the European food additive code E938). Aerial oxidation, hydrolysis, and other chemical reactions that degrade the products are retarded or prevented entirely. High-purity chemicals and pharmaceuticals are sometimes packed and sealed in argon. In winemaking , argon

1860-461: The AAR type "F" coupler is preferred as these are less likely to become separated in a derailment and become a puncture hazard for other tank cars. A type "E" coupler that has shelves over and under the coupler that prevent the coupler sliding out of position after a derailment is used on some hazardous materials tank cars. In addition, some types of tank cars have a second end plate visible from

1922-603: The Crab Nebula supernova ; this was the first noble-gas molecule detected in outer space . Solid argon hydride (Ar(H 2 ) 2 ) has the same crystal structure as the MgZn 2 Laves phase . It forms at pressures between 4.3 and 220 GPa, though Raman measurements suggest that the H 2 molecules in Ar(H 2 ) 2 dissociate above 175 GPa. Argon is extracted industrially by the fractional distillation of liquid air in

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1984-484: The United Kingdom tank wagons were traditionally four-wheel vehicles. Some long-wheelbase four-wheelers are still in use but bogie vehicles are now used as well. Argon Argon is a chemical element ; it has symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas . Argon is the third most abundant gas in Earth's atmosphere , at 0.934% (9340 ppmv ). It

2046-403: The blast furnace to begin the process of primary steelmaking . The thermally-insulated vessel is mounted on trunnions , and designed to endure extremely high temperatures, as well as keeping the metal in a molten state over extended periods of time. The vessel can be pivoted along its longitudinal axis to empty the pig iron into a ladle . The name is derived from the vessel's resemblance to

2108-556: The inert gas within Schlenk lines and gloveboxes . Argon is preferred to less expensive nitrogen in cases where nitrogen may react with the reagents or apparatus. Argon may be used as the carrier gas in gas chromatography and in electrospray ionization mass spectrometry ; it is the gas of choice for the plasma used in ICP spectroscopy . Argon is preferred for the sputter coating of specimens for scanning electron microscopy . Argon gas

2170-472: The Linde tank car depicted below carries liquefied argon . Cars designed for multiple commodities are constructed of two or more tanks (compartments). Each compartment must have separate fittings. The lower capacity and added complexity of multicompartment cars means that they make up a small percentage of the tank car inventory. The DOT-111 tank car, designed to carry liquids such as denatured fuel ethanol ,

2232-586: The air mixed in with the nitrogen. Argon was also encountered in 1882 through independent research of H. F. Newall and W. N. Hartley. Each observed new lines in the emission spectrum of air that did not match known elements. Prior to 1957, the symbol for argon was "A". This was changed to Ar after the International Union of Pure and Applied Chemistry published the work Nomenclature of Inorganic Chemistry in 1957. Argon constitutes 0.934% by volume and 1.288% by mass of Earth's atmosphere . Air

2294-406: The alkali solution. The arc was powered by a battery of five Grove cells and a Ruhmkorff coil of medium size. The alkali absorbed the oxides of nitrogen produced by the arc and also carbon dioxide. They operated the arc until no more reduction of volume of the gas could be seen for at least an hour or two and the spectral lines of nitrogen disappeared when the gas was examined. The remaining oxygen

2356-514: The atmosphere is maintained by cosmogenic production through the knockout reaction Ar (n,2n) Ar and similar reactions. The half-life of Ar is only 269 years. As a result, the underground Ar, shielded by rock and water, has much less Ar contamination. Dark-matter detectors currently operating with liquid argon include DarkSide , WArP , ArDM , microCLEAN and DEAP . Neutrino experiments include ICARUS and MicroBooNE , both of which use high-purity liquid argon in

2418-493: The atmospheres of the outer planets is 8400 : 1600 : 1. This contrasts with the low abundance of primordial Ar in Earth's atmosphere, which is only 31.5 ppmv (= 9340 ppmv × 0.337%), comparable with that of neon (18.18 ppmv) on Earth and with interplanetary gasses, measured by probes . The atmospheres of Mars , Mercury and Titan (the largest moon of Saturn ) contain argon, predominantly as Ar . The predominance of radiogenic Ar

2480-618: The cars. These marks invariably end in X , meaning that the owner is not a common carrier . Within the rail industry, tank cars are grouped by their type and not by the cargo carried. Food-service tank cars may be lined with stainless steel , glass, or plastic. Tank cars carrying dangerous goods are generally made of different types of steel, depending on the intended cargo and operating pressure. They may also be lined with rubber or coated with specialized coatings for tank protection or product purity purpose. The tank heads are also stronger to prevent ruptures during accidents. The whale-belly type

2542-402: The chance of couplers puncturing adjacent tank cars. However, if cars are prevented from disengaging in a derailment, the torsional forces of a derailing car can be transferred to other cars, resulting in the derailment of the adjacent cars. Insulated cars (which may also incorporate heating or refrigeration systems) are used when the contents must be kept at a certain temperature. For example,

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2604-430: The cheapest. It is inexpensive, since it occurs naturally in air and is readily obtained as a byproduct of cryogenic air separation in the production of liquid oxygen and liquid nitrogen : the primary constituents of air are used on a large industrial scale. The other noble gases (except helium ) are produced this way as well, but argon is the most plentiful by far. The bulk of its applications arise simply because it

2666-433: The death of at least one patient. Blue argon lasers are used in surgery to weld arteries, destroy tumors, and correct eye defects. Argon has also been used experimentally to replace nitrogen in the breathing or decompression mix known as Argox , to speed the elimination of dissolved nitrogen from the blood. Incandescent lights are filled with argon, to preserve the filaments at high temperature from oxidation. It

2728-777: The exterior, to further avoid end punctures. It is also preferable if each tap (valve) is recessed within the body of the tank so as to present a reduced knock-off hazard during a derailment. Tank cars have been involved in many rail disasters, including the Lac-Mégantic derailment in Quebec in 2013, the Nishapur train disaster in Iran in 2004, and the Viareggio train derailment in Italy in 2009. Outside of North America , tank cars are also known as tank wagons or tanker wagons . In

2790-427: The graphite from burning. It is also used in incandescent and fluorescent lighting , and other gas-discharge tubes. It makes a distinctive blue-green gas laser . It is also used in fluorescent glow starters. Argon has approximately the same solubility in water as oxygen and is 2.5 times more soluble in water than nitrogen . Argon is colorless, odorless, nonflammable and nontoxic as a solid, liquid or gas. Argon

2852-523: The heavier noble gases have since been synthesized. The first argon compound with tungsten pentacarbonyl, W(CO) 5 Ar, was isolated in 1975. However, it was not widely recognised at that time. In August 2000, another argon compound, argon fluorohydride (HArF), was formed by researchers at the University of Helsinki , by shining ultraviolet light onto frozen argon containing a small amount of hydrogen fluoride with caesium iodide . This discovery caused

2914-508: The list of prohibited substances and methods, although at this time there is no reliable test for abuse. Although argon is non-toxic, it is 38% more dense than air and therefore considered a dangerous asphyxiant in closed areas. It is difficult to detect because it is colorless, odorless, and tasteless. A 1994 incident, in which a man was asphyxiated after entering an argon-filled section of oil pipe under construction in Alaska , highlights

2976-407: The major source of argon is the decay of K in rocks, Ar will be the dominant isotope, as it is on Earth. Argon produced directly by stellar nucleosynthesis is dominated by the alpha-process nuclide Ar . Correspondingly, solar argon contains 84.6% Ar (according to solar wind measurements), and the ratio of the three isotopes Ar :  Ar :  Ar in

3038-406: The namers. An unreactive gas was suspected to be a component of air by Henry Cavendish in 1785. Argon was first isolated from air in 1894 by Lord Rayleigh and Sir William Ramsay at University College London by removing oxygen , carbon dioxide , water, and nitrogen from a sample of clean air. They first accomplished this by replicating an experiment of Henry Cavendish 's. They trapped

3100-422: The periodic table is actually arranged in order of atomic number (see History of the periodic table ). Argon's complete octet of electrons indicates full s and p subshells. This full valence shell makes argon very stable and extremely resistant to bonding with other elements. Before 1962, argon and the other noble gases were considered to be chemically inert and unable to form compounds; however, compounds of

3162-467: The processing of titanium and other reactive elements. An argon atmosphere is also used for growing crystals of silicon and germanium . Argon is used in the poultry industry to asphyxiate birds, either for mass culling following disease outbreaks, or as a means of slaughter more humane than electric stunning . Argon is denser than air and displaces oxygen close to the ground during inert gas asphyxiation . Its non-reactive nature makes it suitable in

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3224-407: The recognition that argon could form weakly bound compounds, even though it was not the first. It is stable up to 17 kelvins (−256 °C). The metastable ArCF 2 dication, which is valence- isoelectronic with carbonyl fluoride and phosgene , was observed in 2010. Argon-36 , in the form of argon hydride ( argonium ) ions, has been detected in interstellar medium associated with

3286-405: The return trip. Combinations of the two types were attempted, such as boxcars with fluid tanks slung beneath the floors. While the car could certainly carry a load in both directions, the limited tank size made this unsuccessful. A large percentage of tank cars are owned by companies serviced by railroads instead of the railroads themselves. This can be verified by examining the reporting marks on

3348-423: The specification. The agencies also imposed a retrofit schedule to bring in-service cars up to DOT-117 standards. Depending on the volatility of the cargo carried, DOT-111 and CPC-1232 cars would be banned in certain services in a series of cut-off dates, with all such cars out of service or rebuilt by May 1, 2025. Tank car The following major events occurred in the years noted: Many variants exist due to

3410-462: The subsurface environment, it is also produced through neutron capture by K , followed by proton emission. Ar is created from the neutron capture by Ca followed by an alpha particle emission as a result of subsurface nuclear explosions . It has a half-life of 35 days. Between locations in the Solar System , the isotopic composition of argon varies greatly. Where

3472-541: The tank shells be constructed out of 9 ⁄ 16  in (14.2875 mm) steel , with 11-gauge ( 1 ⁄ 8  in or 3.175 mm) sheet metal jackets, 1 ⁄ 2  in (12.7 mm) thick head shields on the ends of the tanks, and improved valves over previous designs. In order to implement the DOT-117 standard, the FRA and TC required that all new tank cars constructed after October 1, 2015 be built to

3534-524: The top. Loading and unloading are done through the protective housing. Tank cars are specialized pieces of equipment. As an example, the interior of the car may be lined with a material, such as glass , or other specialized coatings to isolate the tank contents from the tank shell. Care is taken to ensure that tank contents are compatible with tank construction. As a result of this specialization, tank cars have generally been "one-way" cars. Other cars, like boxcars , can easily be reloaded with other goods for

3596-587: The universe, argon-36 is by far the most common argon isotope , as it is the most easily produced by stellar nucleosynthesis in supernovas . The name "argon" is derived from the Greek word ἀργόν , neuter singular form of ἀργός meaning 'lazy' or 'inactive', as a reference to the fact that the element undergoes almost no chemical reactions. The complete octet (eight electrons) in the outer atomic shell makes argon stable and resistant to bonding with other elements. Its triple point temperature of 83.8058  K

3658-434: The wide variety of liquids and gases transported. Tank cars can be pressurized or non-pressurized, insulated or non-insulated, and designed for single or multiple commodities. Non-pressurized cars have various fittings on the top and may have fittings on the bottom. Some of the top fittings are covered by a protective housing. Pressurized cars have a pressure plate, with all fittings, and a cylindrical protective housing at

3720-532: Was a specialized type of tank car designed to carry pickles . This car consisted of several wooden or metal vats (typically three or four) and was often roofed. Pickles which are preserved in salt brine were loaded through hatches in the roof. A tank container, also known as ISO tank, is a specialized type of container designed to carry bulk liquids, such as chemicals, liquid hydrogen , gases and food grade products. Both hazardous and non hazardous products can be shipped in tank containers. A standard tank container

3782-400: Was reacted with alkaline pyrogallate to leave behind an apparently non-reactive gas which they called argon. Before isolating the gas, they had determined that nitrogen produced from chemical compounds was 0.5% lighter than nitrogen from the atmosphere. The difference was slight, but it was important enough to attract their attention for many months. They concluded that there was another gas in

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3844-535: Was used for over 20 years. GATX 96500 is now on display at the National Museum of Transportation in Saint Louis, Missouri . This car is 98 feet (29.87 m) long, weighs 175,000 lb (79,400 kg) empty and rides on four two- axle trucks for weight distribution. It transported diverse substances, such as liquefied petroleum gas (LPG) and anhydrous ammonia . Where AAR couplers are fitted,

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