title: Nixie tube

text: Other numeric-display technologies concurrently in use included backlit columnar transparencies ("thermometer displays"), light pipes, rear-projection and edge-lit lightguide displays (all using individual incandescent or neon light bulbs for illumination), Numitron incandescent filament readouts, Panaplex seven-segment displays, and vacuum fluorescent display tubes. Before Nixie tubes became prominent, most numeric displays were electromechanical, using stepping mechanisms to display digits either directly by use of cylinders bearing printed numerals attached to their rotors, or indirectly by wiring the outputs of stepping switches to indicator bulbs. Later, a few vintage clocks even used a form of stepping switch to drive Nixie tubes.


title: Nixie tube

text: Nixie tubes were superseded in the 1970s by light-emitting diodes (LEDs) and vacuum fluorescent displays (VFDs), often in the form of seven-segment displays. The VFD uses a hot filament to emit electrons, a control grid and phosphor-coated anodes (similar to a cathode ray tube) shaped to represent segments of a digit, pixels of a graphical display, or complete letters, symbols, or words. Whereas Nixies typically require 180 volts to illuminate, VFDs only require relatively low voltages to operate, making them easier and cheaper to use. VFDs have a simple internal structure, resulting in a bright, sharp, and unobstructed image. Unlike Nixies, the glass envelope of a VFD is evacuated rather than being filled with a specific mixture of gases at low pressure.


title: Nixie tube

text: Specialized high-voltage driver chips such as the 7441/74141 were available to drive Nixies. LEDs are better suited to the low voltages that semiconductor integrated circuits typically use, which was an advantage for devices such as pocket calculators, digital watches, and handheld digital measurement instruments. Also, LEDs are much smaller and sturdier, without a fragile glass envelope. LEDs use less power than VFDs or Nixie tubes with the same function.


title: Nixie tube

text: Citing dissatisfaction with the aesthetics of modern digital displays and a nostalgic fondness for the styling of obsolete technology, significant numbers of electronics enthusiasts have shown interest in reviving Nixies. Unsold tubes that have been sitting in warehouses for decades are being brought out and used, the most common application being in homemade digital clocks. During their heyday, Nixies were generally considered too expensive for use in mass-market consumer goods such as clocks. This recent surge in demand has caused prices to rise significantly, particularly for large tubes, making small-scale production of new devices again viable.


title: Nixie tube

text: In addition to the tube itself, another important consideration is the relatively high-voltage circuitry necessary to drive the tube. The original 7400 series drivers integrated circuits such as the 74141 BCD decoder driver have long since been out of production and are rarer than NOS tubes. Only "Integral" in Belarus lists the 74141 and its Soviet equivalent, the K155ID1, is still in production. However, modern bipolar transistors with high voltage ratings are now available cheaply, such as MPSA92 or MPSA42.


title: Corbevax

text: Corbevax is a protein subunit COVID-19 vaccine<ref "name="CTRI/2020/11/029032"></ref> developed by Texas Children's Hospital Center for Vaccine Development and Baylor College of Medicine in Houston, Texas and Dynavax technologies based in Emeryville, California. It is licensed to Indian biopharmaceutical firm Biological E. Limited (BioE) for development and production.


title: Corbevax

text: The vaccine consists of a version of the receptor binding domain (RBD) of the SARS‑CoV‑2 spike protein, together with the adjuvants aluminium hydroxide gel and CpG 1018. The protein is produced by the yeast "Pichia pastoris"; the process is similar to that of existing Hepatitis B vaccines.


title: Corbevax

text: In April 2021, the U.S. International Development Finance Corporation (DFC) announced that it would fund the expansion of Biological E's manufacturing capabilities, so that it could produce at least 1 billion doses by the end of 2022.


title: Corbevax

text: A phase I clinical trial was carried out to evaluate the safety and immunogenicity of the vaccine candidate in about 360 participants. The phase II concluded in April 2021.


title: Corbevax

text: In April 2021, the Drugs Controller General of India permitted the vaccine candidate to start phase III clinical trials. A total of 1,268 healthy participants between the age of 18 and 80 years to be selected from 15 sites across India for the trial and intended to be part of a larger global Phase III study. As of December 2021, Biological E announced positive results, but some experts criticized the lack of public data from phase III trials. The developer specifically claimed the vaccine appeared to be over 90% effective against the original variant based on antibody levels.


title: Corbevax

text: The development of the vaccine was financed with $7 million from mostly private investors, including a $1 million donation by Tito's Vodka. The vaccine technology is given patent-free to manufacturers, although Baylor College receives a fee.


title: Corbevax

text: On 3 June 2021, India's Ministry of Health and Family Welfare pre-ordered 300 million doses of Corbevax.


title: Corbevax

text: The BioE company estimated the vaccine to be priced at ₹250 (around $3) per dose and may even be priced below ₹400 (around $5) for two doses in India.


title: Corbevax

text: The vaccine is planned for use in low-income countries to increase vaccine access and equity, and thus is designed to be easily storable and manufactured with traditional processes. The vaccine is not patented and is planned to be openly licensed under COVAX.


title: Corbevax

text: In January 2022, the scientists developing Corbevax have declared that no G7 countries were yet funding the open source vaccine and reiterated their plea to the US federal government and G7 countries to provide funding for the mass production and distribution of Corbevax, arguing that Moderna had received much more support.


title: Gaite Jansen

text: At age 12, she was awarded the Best Actress Award at the 48 Hour Film Project in Amsterdam for her role in Luwte. Her performance as a troubled deaf teenager in the acclaimed arthouse film "170 Hz" (2011) earned her nominations for Best Actress at the Seattle Film Festival and the Netherlands Film Festival. The film "Supernova", in which she plays the lead role, was selected for the Generations competition at Berlinale film festival 2014.


title: Gaite Jansen

text: In 2014, Jansen made her stage debut at the prestigious Amsterdam Theatre Group, as Ophelia in "Hamlet vs. Hamlet", directed by Guy Cassiers and played in Medea later that year.


title: Gaite Jansen

text: In 2015, Jansen appeared as the lead role in the film "Greenland". She played a suicidal girl in "In Therapie", the Dutch version of "BeTipul" in 2010. She was nominated "best actress" at the Gouden Kalf awards in 2012 for her role in "170 Hz", where she played a deaf girl and conversed mostly in Dutch Sign Language.


title: Gaite Jansen

text: Jansen also plays the role of Duchess Tatiana Petrovna in the third season of the BBC gangster drama "Peaky Blinders".


title: Gaite Jansen

text: In 2017 she appeared as Hana Raznikova in "Line of Duty". She plays Phoenix in the Cinemax TV series "Jett".


title: Shimano

text: , originally and later , is a Japanese multinational manufacturing company for cycling components, fishing tackles and rowing equipment, who also produced golf supplies until 2005 and snowboarding gear until 2008. Named after founder Shozaburo Shimano (, 1894–1958) and headquartered in Sakai, Osaka Prefecture, the company has 32 consolidated and 11 unconsolidated subsidiaries, with the primary manufacturing plants based in Kunshan (China), Malaysia and Singapore.


title: Shimano

text: In 2017, Shimano had net sales of US $3.2 billion, 38% in Europe, 35% in Asia, and 11% in North America. Bicycle components represented 80%, fishing tackle 19%, and other products 0.1%. The company is publicly traded, with 93 million shares of common stock outstanding.


title: Shimano

text: Shimano sales constitute an estimated 70–80% of the global bicycle component market by value. Its products include drivetrain, brake, wheel and pedal components for road, mountain, track and hybrid bikes. The components include cranksets comprising cranks and chainrings; bottom brackets; chains; rear chain sprockets and cassettes; front and rear wheel hubs; gear shift levers; brakes; brake levers; cables; front and rear dérailleurs. Shimano Total Integration (STI) is Shimano's integrated shifter and brake lever combination for road bicycles. The Italian firm Campagnolo as well as US based SRAM are Shimano's primary competitors in the cycling marketplace.


title: Shimano

text: When the 1970s United States bike boom exceeded the capacity of the European bicycle component manufacturers, Japanese manufacturers SunTour and Shimano rapidly stepped in to fill the void. While both companies provided products for all price-ranges of the market, SunTour also focused on refinement of existing systems and designs for higher-end products, while Shimano initially paid more attention to rethinking the basic systems and bringing out innovations such as Positron shifting (a precursor to index shifting) and front freewheel systems at the low end of the market. In the 1980s, with Shimano pushing technological innovation and lower prices, the more traditional European component manufacturers lost significant market presence. During this period, in contrast to the near-universal marketing technique of introducing innovations on the expensive side of the marketplace and relying on consumer demand to emulate early adopters along with economy of scale to bring them into the mass market, Shimano and SunTour (to a lesser extent) introduced new technologies at the lowest end of the bicycle market, using lower cost and often heavier and less durable materials and techniques, only moving them further upmarket if they established themselves in the lower market segments.


title: Shimano

text: In the 1980–1983 period, Shimano introduced three groupsets with "AX" technology: Dura-Ace & 600 (high-end), and Adamas in the low-end. Features of these components include aerodynamic styling, center-pull brakes, brake levers with concealed cables, and ergonomic pedals. By 1985 Shimano introduced innovation only at the highest quality level (Dura-Ace for road bikes and XT for mountain bikes), then trickled the technology down to lower production levels as it became proven and accepted. Innovations include index shifting (known as SIS, Shimano Index System introduced in 1984), freehubs, dual-pivot brakes, 8-9-10 speed drivetrains, and the integration of shifters and brake levers. Also, these components could only work properly when used with other Shimano components; for example, its rear derailleurs have to be used with the correct Shimano gear levers, cables, freehub, and cassette. SunTour tried to catch up, but by the end of the 1980s they had lost the technological and commercial battle, and Shimano had become the largest manufacturer of bicycle components in the world.


title: Shimano

text: Shimano's marketplace domination that developed in the 1990s quickly led to the perception by some critics that Shimano had become a marketplace bully with monopolistic intentions. This viewpoint was based on the fact that Shimano became oriented towards integrating all of their components with each other, with the result being that if any Shimano components were to be used, then the entire bike would need to be built from matching Shimano components. The alternative perspective is that by controlling the mix of components on the bicycle, a manufacturer such as Shimano can control how well their own product functions. Shimano's primary competitors (Campagnolo and SRAM) also make proprietary designs that limit the opportunity to mix and match componentry.


title: Shimano

text: In 2003 Shimano introduced "Dual Control" to mountain bikes, where the gear shift mechanism is integrated into the brake levers. This development was controversial, as the use of Dual Control integrated shifting for hydraulic disc brakes required using Shimano hydraulic disc brakes, locking competitors out of the premium end of the market. However, with their 2007 product line, Shimano moved back to making separate braking and shifting components fully available in addition to the integrated "Dual Control" components, a move to satisfy riders that wished to use Shimano shifting with other brands of disc brakes.


title: Shimano

text: Shimano in 1990 introduced the Shimano Pedaling Dynamics (SPD) range of clipless pedals and matching shoes, designed so that the shoes could be used for walking. The shoes have a recess in the bottom of the sole for fitting the smaller cleats and therefore it does not protrude, while conventional clipless road pedals are designed for road cycling shoes that have smooth soles with large protruding cleats, which are awkward for walking. The SPD range, in addition to other off-road refinements, was designed to be used with treaded soles that more closely resemble rugged hiking boots. SPD pedals and shoes soon established themselves as the market standard in this sector, although many other manufacturers have developed alternatives that may be less prone to being clogged by mud or easier to adjust. However, the SPD dominance in this sector has meant that alternative pedal manufacturers nearly always design their pedals to be usable with Shimano shoes, and likewise mountain bike shoe manufacturers make their shoes "Shimano SPD" compatible. SPD has spawned 2 types of road cleats that are incompatible with standard SPD pedals and some shoes – SPD-R and SPD-SL. SPD-R is a now-defunct pedal standard. SPD-SL is basically a copy of the standard Look clipless pedal system. It has a wide, one-sided platform and a triangular cleat that is Look 3-bolt compatible.


title: Shimano

text: Alexi Grewal used a bicycle equipped with Shimano DynaDrive chainset and pedals (the remainder of the components on his bicycle were primarily Suntour and DiaCompe) to win the 1984 Olympic road race in Los Angeles. In the 1988 Giro d'Italia, Andrew Hampsten rode Shimano to its first Grand Tour victory. In 2002, world championships in both the road and time trial disciplines were won on Shimano equipment. Alberto Contador's 2007 victory in the Tour de France on a Shimano-equipped bicycle represents the first official General Classification victory in that race by a rider using Shimano components (Lance Armstrong originally won the TDF with Shimano in 1999 but was later disqualified due to drug use).


title: Shimano

text: "VIA" ("Vehicle Inspection Association") is stamped on all Shimano parts. It is an official approval stamp used to certify parts of Japanese vehicles – including bicycles. This mark signifies compliance with certain quality standards.


title: Shimano

text: The first Shimano MTB groupset was Deore XT in 1983. It was based on a 1981 Deore derailleur built for touring.


title: Shimano

text: Shimano offers a range of fishing tackles including reels, rods, lines, lures, as well as various fishing accessories, apparels and electronics. Their spinning reels are their best-selling product series in the world.


title: Shimano

text: Shimano has 13,000 employees (2017). Shimano runs fabrications in Japan, China, Malaysia and Singapore.


title: Shimano

text: Shimano is a founding member of the Global Alliance for EcoMobility, an international partnership that works to promote EcoMobility and thus reduce citizens’ dependency on private motorized vehicles worldwide. The EcoMobility Alliance was founded by a group of leading global organizations on the occasion of the Climate Change Conference in Bali in December 2007.


title: KyivNotKiev

text: KyivNotKiev is an online campaign started by the Ukrainian Ministry of Foreign Affairs (MFA) together with the 15 member centre for strategic communications "StratCom Ukraine" on 2 October 2018. Its goal was to persuade English-language media and organizations to exclusively use "Kyiv" (derived from the Ukrainian language name ) instead of "Kiev" (derived from the Russian language name ) as the name of the Ukrainian capital. It is a part of the wider CorrectUA campaign. It is also part of a global trend of city name changes.


title: KyivNotKiev

text: The organization intends to internationally assert a Ukrainian identity and help shed linguistic relics of the Russian Empire and Soviet Union by promoting the exclusive use of Ukrainian-language transliterations for Ukrainian place names. The campaign is run by the Department of Public Diplomacy of the MFA.


title: KyivNotKiev

text: The transliteration "Kyiv" was legally mandated by the Ukrainian government in 1995. The transliteration was approved by the Tenth United Nations Conference on Standardization of Geographical Names in 2012, but did not catch on internationally. Prior to 2019, there were few cases of organizations switching to the "Kyiv" spelling, because many people outside Ukraine did not see the need or thought that the issue was "imposed by nationalists on purpose". After the Russo-Ukrainian War began in 2014, many Western media outlets opted to switch spellings. The war and international political opinions only intensified with Russia's invasion of Ukraine in 2022.


title: KyivNotKiev

text: The "KyivNotKiev" campaign is part of the broader "CorrectUA" campaign, which advocates a change of name in English; not only for Kyiv, but also for other Ukrainian cities whose English names are derived from their Russian spellings. Examples of settlement names derived from Russian include: "Odessa" instead of "Odesa", "Kharkov" instead of "Kharkiv", "Lvov" instead of "Lviv", "Nikolaev" instead of "Mykolaiv", and "Rovno" instead of "Rivne". In English, was used in print as early as 1804 in John Cary's "New map of Europe, from the latest authorities" which appeared in "Cary's New Universal Atlas" published in London, as well as in Mary Holderness's travelogue "New Russia: Journey from Riga to the Crimea by way of Kiev", published in 1823. The "Oxford English Dictionary" included "Kiev" in a quotation by 1883, and "Kyiv" in 2018. Transliterations based on Russian names became common practice because of aggressive Russification policies from the Russian Imperial and later Soviet governments.


title: KyivNotKiev

text: The campaign also includes advice on the usage of the definite article (the) before the name of the country, i.e. "the Ukraine". The definite article is rarely found before the names of independent states, most stemming from the name either being a noun-adjective term or from a geographical region; for Ukraine, the addition of "the" is hypothesized to either derive from its time as the Ukrainian Soviet Socialist Republic (compare with "the Russian Federation") or due to the word originally meaning "borderland", hence saying "the Ukraine" as meaning "the borderlands" (compare with "The Netherlands"). However, many Ukrainians regard the use of "the Ukraine" as tantamount to questioning Ukrainian sovereignty, especially after the beginning of the Russian military intervention into Ukraine. Others hold that this campaign is nothing more than populism and was started to make it look like something was being done to divert attention from more important problems.


title: KyivNotKiev

text: The "KyivNotKiev" campaign began with a fortnight-long "marathon" where every one or two days the MFA published the title of foreign news outlets. Ukrainians would, "en masse", request them on social networks to use "Kyiv" instead of "Kiev", which was also followed by numerous Ukrainian social networks users putting "#KyivNotKiev" frames on their avatars. Ten of the most influential (in the opinion of the MFA) English language global news outlets were affected: Reuters, CNN, BBC News, "Al Jazeera", "Daily Mail", "The Washington Post", "The New York Times", "The Guardian", "The Wall Street Journal" and Euronews. Among the top Ukrainian officials who took part were: Minister of Healthcare, Ulana Suprun; Representative of Ukraine at the Council of Europe, Dmytro Kuleba; and the Member of the "Verkhovna Rada", Yehor Soboliev. The campaign won the support of thousands of Ukrainians, and the hashtag "#KyivNotKiev" was seen by more 10 million social network users. During or shortly after this "marathon", the BBC and "The Guardian" started using "Kyiv". Later, the campaign shifted its attention to foreign airports, which used "Kiev" almost exclusively.


title: KyivNotKiev

text: After the campaign began, the name "Kyiv" became more common on such Anglophone outlets as the BBC, "The Guardian", Associated Press, "The Wall Street Journal", "The Globe and Mail", "The Washington Post", "Financial Times", "The Economist", "The Daily Telegraph", "The New York Times" and other foreign media. It was also adopted by some international organizations.


title: KyivNotKiev

text: In June 2019, at the request of the United States Department of State, the Embassy of Ukraine to the United States, and Ukrainian organizations in America, the name "Kyiv" was officially adopted by the United States Board on Geographic Names as the only correct one, which resulted in the federal government of the United States solely using 'Kyiv'. Before that, both names were used.


title: KyivNotKiev

text: One of the objectives of the campaign was to convince international airports around the world to switch from "Kiev" to "Kyiv". Previously, most airports refused to do so, saying that in lists of the International Air Transport Association (IATA) and International Civil Aviation Organization (ICAO) the name "Kiev" was specified. However, in October 2019, IATA, following the decision of the U.S. Board on Geographic Names, switched to "Kyiv". Since the campaign's launch, 63 airports and 3 airlines worldwide (as of January 2020) have begun using the name "Kyiv", even before it was adopted by IATA. Among them were Toronto Pearson, Luton, Manchester, Frankfurt, and Josep Tarradellas Barcelona–El Prat.


title: KyivNotKiev

text: As of 2022, the remaining major news websites that continue to use "Kiev" are mostly Russian-linked sites funded by the Kremlin, such as the English service of TASS, Sputnik News and RT. These channels also habitually use Russian transliteration for all Ukrainian proper names, such as Kharkov, Chernigov, Krivoy Rog, current Ukrainian president Vladimir Zelensky and former Ukrainian president Pyotr Poroshenko.


title: Metrology

text: Metrology is the scientific study of measurement. It establishes a common understanding of units, crucial in linking human activities. Modern metrology has its roots in the French Revolution's political motivation to standardise units in France when a length standard taken from a natural source was proposed. This led to the creation of the decimal-based metric system in 1795, establishing a set of standards for other types of measurements. Several other countries adopted the metric system between 1795 and 1875; to ensure conformity between the countries, the Bureau International des Poids et Mesures (BIPM) was established by the Metre Convention. This has evolved into the International System of Units (SI) as a result of a resolution at the 11th General Conference on Weights and Measures (CGPM) in 1960.


title: Metrology

text: In each country, a national measurement system (NMS) exists as a network of laboratories, calibration facilities and accreditation bodies which implement and maintain its metrology infrastructure. The NMS affects how measurements are made in a country and their recognition by the international community, which has a wide-ranging impact in its society (including economics, energy, environment, health, manufacturing, industry and consumer confidence). The effects of metrology on trade and economy are some of the easiest-observed societal impacts. To facilitate fair trade, there must be an agreed-upon system of measurement.


title: Metrology

text: The ability to measure alone is insufficient; standardisation is crucial for measurements to be meaningful. The first record of a permanent standard was in 2900 BC, when the royal Egyptian cubit was carved from black granite. The cubit was decreed to be the length of the Pharaoh's forearm plus the width of his hand, and replica standards were given to builders. The success of a standardised length for the building of the pyramids is indicated by the lengths of their bases differing by no more than 0.05 percent.


title: Metrology

text: Other civilizations produced generally accepted measurement standards, with Roman and Greek architecture based on distinct systems of measurement. The collapse of the empires and the Dark Ages that followed lost much measurement knowledge and standardisation. Although local systems of measurement were common, comparability was difficult since many local systems were incompatible. England established the Assize of Measures to create standards for length measurements in 1196, and the 1215 Magna Carta included a section for the measurement of wine and beer.


title: Metrology

text: Modern metrology has its roots in the French Revolution. With a political motivation to harmonise units throughout France, a length standard based on a natural source was proposed. In March 1791, the metre was defined. This led to the creation of the decimal-based metric system in 1795, establishing standards for other types of measurements. Several other countries adopted the metric system between 1795 and 1875; to ensure international conformity, the International Bureau of Weights and Measures (, or BIPM) was formed by the Metre Convention. Although the BIPM's original mission was to create international standards for units of measurement and relate them to national standards to ensure conformity, its scope has broadened to include electrical and photometric units and ionizing radiation measurement standards. The metric system was modernised in 1960 with the creation of the International System of Units (SI) as a result of a resolution at the 11th General Conference on Weights and Measures (, or CGPM).


title: Metrology

text: Metrology is defined by the International Bureau of Weights and Measures (BIPM) as "the science of measurement, embracing both experimental and theoretical determinations at any level of uncertainty in any field of science and technology". It establishes a common understanding of units, crucial to human activity. Metrology is a wide reaching field, but can be summarized through three basic activities: the definition of internationally accepted units of measurement, the realisation of these units of measurement in practice, and the application of chains of traceability (linking measurements to reference standards). These concepts apply in different degrees to metrology's three main fields: scientific metrology; applied, technical or industrial metrology, and legal metrology.


title: Metrology

text: Scientific metrology is concerned with the establishment of units of measurement, the development of new measurement methods, the realisation of measurement standards, and the transfer of traceability from these standards to users in a society. This type of metrology is considered the top level of metrology which strives for the highest degree of accuracy. BIPM maintains a database of the metrological calibration and measurement capabilities of institutes around the world. These institutes, whose activities are peer-reviewed, provide the fundamental reference points for metrological traceability. In the area of measurement, BIPM has identified nine metrology areas, which are acoustics, electricity and magnetism, length, mass and related quantities, photometry and radiometry, ionizing radiation, time and frequency, thermometry, and chemistry.


title: Metrology

text: As of May 2019 no physical objects define the base units. The motivation in the change of the base units is to make the entire system derivable from physical constants, which required the removal of the prototype kilogram as it is the last artefact the unit definitions depend on. Scientific metrology plays an important role in this redefinition of the units as precise measurements of the physical constants is required to have accurate definitions of the base units. To redefine the value of a kilogram without an artefact the value of the Planck constant must be known to twenty parts per billion. Scientific metrology, through the development of the Kibble balance and the Avogadro project, has produced a value of Planck constant with low enough uncertainty to allow for a redefinition of the kilogram.


title: Metrology

text: Applied, technical or industrial metrology is concerned with the application of measurement to manufacturing and other processes and their use in society, ensuring the suitability of measurement instruments, their calibration and quality control. Producing good measurements is important in industry as it has an impact on the value and quality of the end product, and a 10–15% impact on production costs. Although the emphasis in this area of metrology is on the measurements themselves, traceability of the measuring-device calibration is necessary to ensure confidence in the measurement. Recognition of the metrological competence in industry can be achieved through mutual recognition agreements, accreditation, or peer review. Industrial metrology is important to a country's economic and industrial development, and the condition of a country's industrial-metrology program can indicate its economic status.


title: Metrology

text: Legal metrology "concerns activities which result from statutory requirements and concern measurement, units of measurement, measuring instruments and methods of measurement and which are performed by competent bodies". Such statutory requirements may arise from the need for protection of health, public safety, the environment, enabling taxation, protection of consumers and fair trade. The International Organization for Legal Metrology (OIML) was established to assist in harmonising regulations across national boundaries to ensure that legal requirements do not inhibit trade. This harmonisation ensures that certification of measuring devices in one country is compatible with another country's certification process, allowing the trade of the measuring devices and the products that rely on them. WELMEC was established in 1990 to promote cooperation in the field of legal metrology in the European Union and among European Free Trade Association (EFTA) member states. In the United States legal metrology is under the authority of the Office of Weights and Measures of National Institute of Standards and Technology (NIST), enforced by the individual states.


title: Metrology

text: The International System of Units (SI) defines seven base units: length, mass, time, electric current, thermodynamic temperature, amount of substance, and luminous intensity. By convention, each of these units are considered to be mutually independent and can be constructed directly from their defining constants. All other SI units are constructed as products of powers of the seven base units.


title: Metrology

text: Since the base units are the reference points for all measurements taken in SI units, if the reference value changed all prior measurements would be incorrect. Before 2019, if a piece of the international prototype of the kilogram had been snapped off, it would have still been defined as a kilogram; all previous measured values of a kilogram would be heavier. The importance of reproducible SI units has led the BIPM to complete the task of defining all SI base units in terms of physical constants.


title: Metrology

text: By defining SI base units with respect to physical constants, and not artefacts or specific substances, they are realisable with a higher level of precision and reproducibility. As of the redefinition of the SI units on 20 May 2019 the kilogram, ampere, kelvin, and mole are defined by setting exact numerical values for the Planck constant ('), the elementary electric charge ('), the Boltzmann constant ('), and the Avogadro constant (), respectively. The second, metre, and candela have previously been defined by physical constants (the caesium standard (Δ"ν"), the speed of light ('), and the luminous efficacy of visible light radiation ("K")), subject to correction to their present definitions. The new definitions aim to improve the SI without changing the size of any units, thus ensuring continuity with existing measurements.


title: Metrology

text: The realisation of a unit of measure is its conversion into reality. Three possible methods of realisation are defined by the (VIM): a physical realisation of the unit from its definition, a highly-reproducible measurement as a reproduction of the definition (such as the quantum Hall effect for the ohm), and the use of a material object as the measurement standard.


title: Metrology

text: A standard (or etalon) is an object, system, or experiment with a defined relationship to a unit of measurement of a physical quantity. Standards are the fundamental reference for a system of weights and measures by realising, preserving, or reproducing a unit against which measuring devices can be compared. There are three levels of standards in the hierarchy of metrology: primary, secondary, and working standards. Primary standards (the highest quality) do not reference any other standards. Secondary standards are calibrated with reference to a primary standard. Working standards, used to calibrate (or check) measuring instruments or other material measures, are calibrated with respect to secondary standards. The hierarchy preserves the quality of the higher standards. An example of a standard would be gauge blocks for length. A gauge block is a block of metal or ceramic with two opposing faces ground precisely flat and parallel, a precise distance apart. The length of the path of light in vacuum during a time interval of 1/299,792,458 of a second is embodied in an artefact standard such as a gauge block; this gauge block is then a primary standard which can be used to calibrate secondary standards through mechanical comparators.


title: Metrology

text: Metrological traceability is defined as the "property of a measurement result whereby the result can be related to a reference through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty". It permits the comparison of measurements, whether the result is compared to the previous result in the same laboratory, a measurement result a year ago, or to the result of a measurement performed anywhere else in the world. The chain of traceability allows any measurement to be referenced to higher levels of measurements back to the original definition of the unit.


title: Metrology

text: Traceability is most often obtained by calibration, establishing the relationship between an indication on a measuring instrument (or secondary standard) and the value of the standard. A calibration is an operation that establishes a relation between a measurement standard with a known measurement uncertainty and the device that is being evaluated. The process will determine the measurement value and uncertainty of the device that is being calibrated and create a traceability link to the measurement standard. The four primary reasons for calibrations are to provide traceability, to ensure that the instrument (or standard) is consistent with other measurements, to determine accuracy, and to establish reliability. Traceability works as a pyramid, at the top level there is the international standards, at the next level national metrology institutes calibrate the primary standards through realisation of the units creating the traceability link from the primary standard and the unit definition. Through subsequent calibrations between national metrology institutes, calibration laboratories, and industry and testing laboratories the realisation of the unit definition is propagated down through the pyramid. The traceability chain works upwards from the bottom of the pyramid, where measurements done by industry and testing laboratories can be directly related to the unit definition at the top through the traceability chain created by calibration.


title: Metrology

text: Measurement uncertainty is a value associated with a measurement which expresses the spread of possible values associated with the measurand—a quantitative expression of the doubt existing in the measurement. There are two components to the uncertainty of a measurement: the width of the uncertainty interval and the confidence level. The uncertainty interval is a range of values that the measurement value expected to fall within, while the confidence level is how likely the true value is to fall within the uncertainty interval. Uncertainty is generally expressed as follows:


title: Metrology

text: Where "y" is the measurement value and "U" is the uncertainty value and "k" is the coverage factor indicates the confidence interval. The upper and lower limit of the uncertainty interval can be determined by adding and subtracting the uncertainty value from the measurement value. The coverage factor of "k" = 2 generally indicates a 95% confidence that the measured value will fall inside the uncertainty interval. Other values of "k" can be used to indicate a greater or lower confidence on the interval, for example "k" = 1 and "k" = 3 generally indicate 66% and 99.7% confidence respectively. The uncertainty value is determined through a combination of statistical analysis of the calibration and uncertainty contribution from other errors in measurement process, which can be evaluated from sources such as the instrument history, manufacturer's specifications, or published information.


title: Metrology

text: The Metre Convention created three main international organizations to facilitate standardisation of weights and measures. The first, the General Conference on Weights and Measures (CGPM), provided a forum for representatives of member states. The second, the International Committee for Weights and Measures (CIPM), was an advisory committee of metrologists of high standing. The third, the International Bureau of Weights and Measures (BIPM), provided secretarial and laboratory facilities for the CGPM and CIPM.


title: Metrology

text: The General Conference on Weights and Measures (, or CGPM) is the convention's principal decision-making body, consisting of delegates from member states and non-voting observers from associate states. The conference usually meets every four to six years to receive and discuss a CIPM report and endorse new developments in the SI as advised by the CIPM. The last meeting was held on 13–16 November 2018. On the last day of this conference there was vote on the redefinition of four base units, which the International Committee for Weights and Measures (CIPM) had proposed earlier that year. The new definitions came into force on 20 May 2019.


title: Metrology

text: The International Committee for Weights and Measures (, or CIPM) is made up of eighteen (originally fourteen) individuals from a member state of high scientific standing, nominated by the CGPM to advise the CGPM on administrative and technical matters. It is responsible for ten consultative committees (CCs), each of which investigates a different aspect of metrology; one CC discusses the measurement of temperature, another the measurement of mass, and so forth. The CIPM meets annually in Sèvres to discuss reports from the CCs, to submit an annual report to the governments of member states concerning the administration and finances of the BIPM and to advise the CGPM on technical matters as needed. Each member of the CIPM is from a different member state, with France (in recognition of its role in establishing the convention) always having one seat.


title: Metrology

text: The International Bureau of Weights and Measures (, or BIPM) is an organisation based in Sèvres, France which has custody of the international prototype of the kilogram, provides metrology services for the CGPM and CIPM, houses the secretariat for the organisations and hosts their meetings. Over the years, prototypes of the metre and of the kilogram have been returned to BIPM headquarters for recalibration. The BIPM director is an ex officio member of the CIPM and a member of all consultative committees.


title: Metrology

text: The International Organization of Legal Metrology (, or OIML), is an intergovernmental organization created in 1955 to promote the global harmonisation of the legal metrology procedures facilitating international trade. This harmonisation of technical requirements, test procedures and test-report formats ensure confidence in measurements for trade and reduces the costs of discrepancies and measurement duplication. The OIML publishes a number of international reports in four categories:


title: Metrology

text: Although the OIML has no legal authority to impose its recommendations and guidelines on its member countries, it provides a standardised legal framework for those countries to assist the development of appropriate, harmonised legislation for certification and calibration. OIML provides a mutual acceptance arrangement (MAA) for measuring instruments that are subject to legal metrological control, which upon approval allows the evaluation and test reports of the instrument to be accepted in all participating countries. Issuing participants in the agreement issue MAA Type Evaluation Reports of MAA Certificates upon demonstration of compliance with ISO/IEC 17065 and a peer evaluation system to determine competency. This ensures that certification of measuring devices in one country is compatible with the certification process in other participating countries, allowing the trade of the measuring devices and the products that rely on them.


title: Metrology

text: The International Laboratory Accreditation Cooperation (ILAC) is an international organisation for accreditation agencies involved in the certification of conformity-assessment bodies. It standardises accreditation practices and procedures, recognising competent calibration facilities and assisting countries developing their own accreditation bodies. ILAC originally began as a conference in 1977 to develop international cooperation for accredited testing and calibration results to facilitate trade. In 2000, 36 members signed the ILAC mutual recognition agreement (MRA), allowing members work to be automatically accepted by other signatories, and in 2012 was expanded to include accreditation of inspection bodies. Through this standardisation, work done in laboratories accredited by signatories is automatically recognised internationally through the MRA. Other work done by ILAC includes promotion of laboratory and inspection body accreditation, and supporting the development of accreditation systems in developing economies.


title: Metrology

text: The Joint Committee for Guides in Metrology (JCGM) is a committee which created and maintains two metrology guides: "Guide to the expression of uncertainty in measurement" (GUM) and "International vocabulary of metrology – basic and general concepts and associated terms" (VIM). The JCGM is a collaboration of eight partner organisations:


title: Metrology

text: The JCGM has two working groups: JCGM-WG1 and JCGM-WG2. JCGM-WG1 is responsible for the GUM, and JCGM-WG2 for the VIM. Each member organization appoints one representative and up to two experts to attend each meeting, and may appoint up to three experts for each working group.


title: Metrology

text: A national measurement system (NMS) is a network of laboratories, calibration facilities and accreditation bodies which implement and maintain a country's measurement infrastructure. The NMS sets measurement standards, ensuring the accuracy, consistency, comparability, and reliability of measurements made in the country. The measurements of member countries of the CIPM Mutual Recognition Arrangement (CIPM MRA), an agreement of national metrology institutes, are recognized by other member countries. As of March 2018, there are 102 signatories of the CIPM MRA, consisting of 58 member states, 40 associate states, and 4 international organizations.


title: Metrology

text: A national metrology institute's (NMI) role in a country's measurement system is to conduct scientific metrology, realise base units, and maintain primary national standards. An NMI provides traceability to international standards for a country, anchoring its national calibration hierarchy. For a national measurement system to be recognized internationally by the CIPM Mutual Recognition Arrangement, an NMI must participate in international comparisons of its measurement capabilities. BIPM maintains a comparison database and a list of calibration and measurement capabilities (CMCs) of the countries participating in the CIPM MRA. Not all countries have a centralised metrology institute; some have a lead NMI and several decentralised institutes specialising in specific national standards. Some examples of NMI's are the National Institute of Standards and Technology (NIST) in the United States, the National Research Council (NRC) in Canada, the Korea Research Institute of Standards and Science (KRISS), and the National Physical Laboratory (United Kingdom) (NPL).


title: Metrology

text: Calibration laboratories are generally responsible for calibrations of industrial instrumentation. Calibration laboratories are accredited and provide calibration services to industry firms, which provides a traceability link back to the national metrology institute. Since the calibration laboratories are accredited, they give companies a traceability link to national metrology standards.


title: Metrology

text: An organisation is accredited when an authoritative body determines, by assessing the organisation's personnel and management systems, that it is competent to provide its services. For international recognition, a country's accreditation body must comply with international requirements and is generally the product of international and regional cooperation. A laboratory is evaluated according to international standards such as ISO/IEC 17025 general requirements for the competence of testing and calibration laboratories. To ensure objective and technically-credible accreditation, the bodies are independent of other national measurement system institutions. The National Association of Testing Authorities in Australia and the United Kingdom Accreditation Service are examples of accreditation bodies.


title: Metrology

text: Metrology has wide-ranging impacts on a number of sectors, including economics, energy, the environment, health, manufacturing, industry, and consumer confidence. The effects of metrology on trade and the economy are two of its most-apparent societal impacts. To facilitate fair and accurate trade between countries, there must be an agreed-upon system of measurement. Accurate measurement and regulation of water, fuel, food, and electricity are critical for consumer protection and promote the flow of goods and services between trading partners. A common measurement system and quality standards benefit consumer and producer; production at a common standard reduces cost and consumer risk, ensuring that the product meets consumer needs. Transaction costs are reduced through an increased economy of scale. Several studies have indicated that increased standardisation in measurement has a positive impact on GDP. In the United Kingdom, an estimated 28.4 percent of GDP growth from 1921 to 2013 was the result of standardisation; in Canada between 1981 and 2004 an estimated nine percent of GDP growth was standardisation-related, and in Germany the annual economic benefit of standardisation is an estimated 0.72% of GDP.


title: Metrology

text: Legal metrology has reduced accidental deaths and injuries with measuring devices, such as radar guns and breathalyzers, by improving their efficiency and reliability. Measuring the human body is challenging, with poor repeatability and reproducibility, and advances in metrology help develop new techniques to improve health care and reduce costs. Environmental policy is based on research data, and accurate measurements are important for assessing climate change and environmental regulation. Aside from regulation, metrology is essential in supporting innovation, the ability to measure provides a technical infrastructure and tools that can then be used to pursue further innovation. By providing a technical platform which new ideas can be built upon, easily demonstrated, and shared, measurement standards allow new ideas to be explored and expanded upon.


title: Hull classification symbol

text: The United States Navy, United States Coast Guard, and United States National Oceanic and Atmospheric Administration (NOAA) use a hull classification symbol (sometimes called hull code or hull number) to identify their ships by type and by individual ship within a type. The system is analogous to the pennant number system that the Royal Navy and other European and Commonwealth navies use.


title: Hull classification symbol

text: The U.S. Navy began to assign unique Naval Registry Identification Numbers to its ships in the 1890s. The system was a simple one in which each ship received a number which was appended to its ship type, fully spelled out, and added parenthetically after the ship's name when deemed necessary to avoid confusion between ships. Under this system, for example, the battleship "Indiana" was USS "Indiana" (Battleship No. 1), the cruiser "Olympia" was USS "Olympia" (Cruiser No. 6), and so on. Beginning in 1907, some ships also were referred to alternatively by single-letter or three-letter codes—for example, USS "Indiana" (Battleship No. 1) could be referred to as USS "Indiana" (B-1) and USS "Olympia" (Cruiser No. 6) could also be referred to as USS "Olympia" (C-6), while USS "Pennsylvania" (Armored Cruiser No. 4) could be referred to as USS "Pennsylvania" (ACR-4). However, rather than replacing it, these codes coexisted and were used interchangeably with the older system until the modern system was instituted on 17 July 1920.


title: Hull classification symbol

text: During World War I, the U.S. Navy acquired large numbers of privately owned and commercial ships and craft for use as patrol vessels, mine warfare vessels, and various types of naval auxiliary ships, some of them with identical names. To keep track of them all, the Navy assigned unique identifying numbers to them. Those deemed appropriate for patrol work received section patrol numbers (SP), while those intended for other purposes received "identification numbers", generally abbreviated "Id. No." or "ID;" some ships and craft changed from an SP to an ID number or vice versa during their careers, without their unique numbers themselves changing, and some ships and craft assigned numbers in anticipation of naval service were never acquired by the Navy. The SP/ID numbering sequence was unified and continuous, with no SP number repeated in the ID series or vice versa so that there could not be, for example, both an "SP-435" and an "Id. No. 435". The SP and ID numbers were used parenthetically after each boat's or ship's name to identify it; although this system pre-dated the modern hull classification system and its numbers were not referred to at the time as "hull codes" or "hull numbers," it was used in a similar manner to today's system and can be considered its precursor.


title: Hull classification symbol

text: The United States Revenue Cutter Service, which merged with the United States Lifesaving Service in January 1915 to form the modern United States Coast Guard, began following the Navy's lead in the 1890s, with its cutters having parenthetical numbers called Naval Registry Identification Numbers following their names, such as (Cutter No. 1), etc. This persisted until the Navy's modern hull classification system's introduction in 1920, which included Coast Guard ships and craft.


title: Hull classification symbol

text: Like the U.S. Navy, the United States Coast and Geodetic Survey – a uniformed seagoing service of the United States Government and a predecessor of the National Oceanic and Atmospheric Administration (NOAA) – adopted a hull number system for its fleet in the 20th century. Its largest vessels, "Category I" oceanographic survey ships, were classified as "ocean survey ships" and given the designation "OSS". Intermediate-sized "Category II" oceanographic survey ships received the designation "MSS" for "medium survey ship," and smaller "Category III" oceanographic survey ships were given the classification "CSS" for "coastal survey ship." A fourth designation, "ASV" for "auxiliary survey vessel," included even smaller vessels. In each case, a particular ship received a unique designation based on its classification and a unique hull number separated by a space rather than a hyphen; for example, the third Coast and Geodetic Survey ship named "Pioneer" was an ocean survey ship officially known as USC&GS "Pioneer" (OSS 31). The Coast and Geodetic Surveys system persisted after the creation of NOAA in 1970, when NOAA took control of the Surveys fleet, but NOAA later changed to its modern hull classification system.


title: Hull classification symbol

text: The Fish and Wildlife Service, created in 1940 and reorganized as the United States Fish and Wildlife Service (USFWS) in 1956, adopted a hull number system for its fisheries research ships and patrol vessels. It consisted of "FWS" followed by a unique identifying number. In 1970, NOAA took control of the seagoing ships of the USFWS′s Bureau of Commercial Fisheries, and as part of the NOAA fleet they eventually were renumbered under the NOAA hull number system.


title: Hull classification symbol

text: The U.S. Navy instituted its modern hull classification system on 17 July 1920, doing away with section patrol numbers, "identification numbers", and the other numbering systems described above. In the new system, all hull classification symbols are at least two letters; for basic types the symbol is the first letter of the type name, doubled, except for aircraft carriers.


title: Hull classification symbol

text: The combination of symbol and hull number identifies a modern Navy ship uniquely. A heavily modified or re-purposed ship may receive a new symbol, and either retain the hull number or receive a new one. For example, the heavy gun cruiser was converted to a gun/missile cruiser, changing the hull number to CAG-1. Also, the system of symbols has changed a number of times both since it was introduced in 1907 and since the modern system was instituted in 1920, so ships' symbols sometimes change without anything being done to the physical ship.


title: Hull classification symbol

text: Hull numbers are assigned by classification. Duplication between, but not within, classifications is permitted. Hence, CV-1 was the aircraft carrier and BB-1 was the battleship .


title: Hull classification symbol

text: Ship types and classifications have come and gone over the years, and many of the symbols listed below are not presently in use. The Naval Vessel Register maintains an online database of U.S. Navy ships showing which symbols are presently in use.


title: Hull classification symbol

text: After World War II until 1975, the U.S. Navy defined a "frigate" as a type of surface warship larger than a destroyer and smaller than a cruiser. In other navies, such a ship generally was referred to as a "flotilla leader", or "destroyer leader". Hence the U.S. Navy's use of "DL" for "frigate" prior to 1975, while "frigates" in other navies were smaller than destroyers and more like what the U.S. Navy termed a "destroyer escort", "ocean escort", or "DE". The United States Navy 1975 ship reclassification of cruisers, frigates, and ocean escorts brought U.S. Navy classifications into line with other nations' classifications, at least cosmetically in terms of terminology, and eliminated the perceived "cruiser gap" with the Soviet Navy by redesignating the former "frigates" as "cruisers".


title: Hull classification symbol

text: If a U.S. Navy ship's hull classification symbol begins with "T-", it is part of the Military Sealift Command, has a primarily civilian crew, and is a United States Naval Ship (USNS) in non-commissioned service – as opposed to a commissioned United States Ship (USS) with an all-military crew.


title: Hull classification symbol

text: If a ship's hull classification symbol begins with "W", it is a commissioned cutter of the United States Coast Guard. Until 1965, the Coast Guard used U.S. Navy hull classification codes, prepending a "W" to their beginning. In 1965, it retired some of the less mission-appropriate Navy-based classifications and developed new ones of its own, most notably WHEC for "high endurance cutter" and WMEC for "medium endurance cutter".


title: Hull classification symbol

text: The National Oceanic and Atmospheric Administration (NOAA), a component of the United States Department of Commerce, includes the National Oceanic and Atmospheric Administration Commissioned Officer Corps (or "NOAA Corps"), one of the eight uniformed services of the United States, and operates a fleet of seagoing research and survey ships. The NOAA fleet also uses a hull classification symbol system, which it also calls "hull numbers," for its ships.


title: Hull classification symbol

text: After NOAA took over the former fleets of the U.S. Coast and Geodetic Survey and the U.S. Fish and Wildlife Service Bureau of Commercial Fisheries in 1970, it adopted a new system of ship classification. In its system, the NOAA fleet is divided into two broad categories, research ships and survey ships. The research ships, which include oceanographic and fisheries research vessels, are given hull numbers beginning with "R", while the survey ships, generally hydrographic survey vessels, receive hull numbers beginning with "S". The letter is followed by a three-digit number; the first digit indicates the NOAA "class" (i.e., size) of the vessel, which NOAA assigns based on the ship's gross tonnage and horsepower, while the next two digits combine with the first digit to create a unique three-digit identifying number for the ship.


title: Hull classification symbol

text: Generally, each NOAA hull number is written with a space between the letter and the three-digit number, as in, for example, or .


title: Hull classification symbol

text: Unlike in the U.S. Navy system, once an older NOAA ship leaves service, a newer one can be given the same hull number; for example, "S 222" was assigned to , then assigned to NOAAS "Thomas Jefferson" (S 222), which entered NOAA service after "Mount Mitchell" was stricken.


title: Hull classification symbol

text: The U.S. Navy's system of alpha-numeric ship designators, and its associated hull numbers, have been for several decades a unique method of categorizing ships of all types: combatants, auxiliaries and district craft. Though considerably changed in detail and expanded over the years, this system remains essentially the same as when formally implemented in 1920. It is a very useful tool for organizing and keeping track of naval vessels, and also provides the basis for the identification numbers painted on the bows (and frequently the sterns) of most U.S. Navy ships.


title: Hull classification symbol

text: The ship designator and hull number system's roots extend back to the late 1880s when ship type serial numbers were assigned to most of the new-construction warships of the emerging "Steel Navy". During the course of the next thirty years, these same numbers were combined with filing codes used by the Navy's clerks to create an informal version of the system that was put in place in 1920. Limited usage of ship numbers goes back even earlier, most notably to the "Jeffersonian Gunboats" of the early 1800s and the "Tinclad" river gunboats of the Civil War Mississippi Squadron.


title: Hull classification symbol

text: It is important to understand that hull number-letter prefixes are not acronyms, and should not be carelessly treated as abbreviations of ship type classifications. Thus, "DD" does not stand for anything more than "Destroyer". "SS" simply means "Submarine". And "FF" is the post-1975 type code for "Frigate."


title: Hull classification symbol

text: The hull classification codes for ships in active duty in the United States Navy are governed under Secretary of the Navy Instruction 5030.8B.


title: Hull classification symbol

text: Aircraft carriers are ships designed primarily for the purpose of conducting combat operations by aircraft which engage in attacks against airborne, surface, sub-surface and shore targets. Contrary to popular belief, the "CV" hull classification symbol does not stand for "carrier vessel". "CV" derives from the cruiser designation, with one popular theory that the V comes from French "voler", "to fly", but this has never been definitively proven. The V has long been used by the U.S. Navy for heavier-than-air craft and possibly comes from the French volplane. Aircraft carriers are designated in two sequences: the first sequence runs from CV-1 USS "Langley" to the very latest ships, and the second sequence, "CVE" for escort carriers, ran from CVE-1 "Long Island" to CVE-127 "Okinawa" before being discontinued.


title: Hull classification symbol

text: Surface combatants are ships which are designed primarily to engage enemy forces on the high seas. The primary surface combatants are battleships, cruisers and destroyers. Battleships are very heavily armed and armored; cruisers moderately so; destroyers and smaller warships, less so. Before 1920, ships were called "<type> no. X", with the type fully pronounced. The types were commonly abbreviated in ship lists to "B-X", "C-X", "D-X" et cetera—for example, before 1920, would have been called "USS "Minnesota", Battleship number 22" orally and "USS "Minnesota", B-22" in writing. After 1920, the ship's name would have been both written and pronounced "USS "Minnesota" (BB-22)". In generally decreasing size, the types are:


title: Hull classification symbol

text: Submarines are all self-propelled submersible types (usually started with SS) regardless of whether employed as combatant, auxiliary, or research and development vehicles which have at least a residual combat capability. While some classes, including all diesel-electric submarines, are retired from USN service, non-U.S. navies continue to employ SS, SSA, SSAN, SSB, SSC, SSG, SSM, and SST types. With the advent of new Air Independent Propulsion/Power (AIP) systems, both SSI and SSP are used to distinguish the types within the USN, but SSP has been declared the preferred term. SSK, retired by the USN, continues to be used colloquially and interchangeably with SS for diesel-electric attack/patrol submarines within the USN, and, more formally, by the Royal Navy and British firms such as Jane's Information Group.


title: Hull classification symbol

text: Patrol combatants are ships whose mission may extend beyond coastal duties and whose characteristics include adequate endurance and seakeeping, providing a capability for operations exceeding 48 hours on the high seas without support. This notably included Brown Water Navy/Riverine Forces during the Vietnam War. Few of these ships are in service today.


title: Hull classification symbol

text: Amphibious warfare vessels include all ships having an organic capability for amphibious warfare and which have characteristics enabling long duration operations on the high seas. There are two classifications of craft: amphibious warfare ships, which are built to cross oceans, and landing craft, which are designed to take troops from ship to shore in an invasion.


title: Hull classification symbol

text: The U.S. Navy hull classification symbol for a ship with a well deck depends on its facilities for aircraft:


title: Hull classification symbol

text: An auxiliary ship is designed to operate in any number of roles supporting combatant ships and other naval operations.


title: Hull classification symbol

text: Mobile logistics ships have the capability to provide direct material support to other deployed units operating far from home ports.


title: Hull classification symbol

text: Support ships are not designed to participate in combat and are generally not armed. For ships with civilian crews (owned by and/or operated for Military Sealift Command and the Maritime Administration), the prefix T- is placed at the front of the hull classification.


title: Hull classification symbol

text: Support ships are designed to operate in the open ocean in a variety of sea states to provide general support to either combatant forces or shore-based establishments. They include smaller auxiliaries which, by the nature of their duties, leave inshore waters.


title: Hull classification symbol

text: Service craft are navy-subordinated craft (including non-self-propelled) designed to provide general support to either combatant forces or shore-based establishments. The suffix "N" refers to non-self-propelled variants.


title: Hull classification symbol

text: Although technically aircraft, pre-World War II rigid airships were treated like commissioned surface warships and submarines, flew the U.S. ensign from their stern and carried a United States Ship (USS) designation. Lighter-than-air aircraft (e.g., blimps) continued to fly the U.S. ensign from their stern but were always considered to be primarily aircraft.


title: Hull classification symbol

text: United States Navy Designations (Temporary) are a form of U.S. Navy ship designation, intended for temporary identification use. Such designations usually occur during periods of sudden mobilization, such as that which occurred prior to, and during, World War II or the Korean War, when it was determined that a sudden temporary need arose for a ship for which there was no official Navy designation.


title: Hull classification symbol

text: During World War II, for example, a number of commercial vessels were requisitioned, or acquired, by the U.S. Navy to meet the sudden requirements of war. A yacht acquired by the U.S. Navy during the start of World War II might seem desirable to the Navy whose use for the vessel might not be fully developed or explored at the time of acquisition.


title: Hull classification symbol

text: On the other hand, a U.S. Navy vessel, such as the yacht in the example above, already in commission or service, might be desired, or found useful, for another need or purpose for which there is no official designation.


title: Hull classification symbol

text: Numerous other U.S. Navy vessels were launched with a temporary, or nominal, designation, such as YMS or PC, since it could not be determined, at the time of construction, what they should be used for. Many of these were vessels in the 150 to 200 feet length class with powerful engines, whose function could be that of a minesweeper, patrol craft, submarine chaser, seaplane tender, tugboat, or other. Once their destiny, or capability, was found or determined, such vessels were reclassified with their actual designation.


title: Hull classification symbol

text: Prior to 1965, U.S. Coast Guard cutters used the same designation as naval ships but preceded by a "W" to indicate Coast Guard commission. The U.S. Coast Guard considers any ship over 65 feet in length with a permanently assigned crew, a cutter.


title: Hull classification symbol

text: The letter is paired with a three-digit number. The first digit of the number is determined by the ships "power tonnage," defined as the sum of its shaft horsepower and gross international tonnage, as follows:


title: 1967 Detroit riot

text: The 1967 Detroit Riot, also known as the 12th Street Riot or Detroit Rebellion, was the bloodiest of the urban riots in the United States during the "Long, hot summer of 1967". Composed mainly of confrontations between Black residents and the Detroit Police Department, it began in the early morning hours of Sunday July 23, 1967, in Detroit, Michigan.


title: 1967 Detroit riot

text: The precipitating event was a police raid of an unlicensed, after-hours bar, known as a "blind pig", on the city's Near West Side. It exploded into one of the deadliest and most destructive riots in American history, lasting five days and surpassing the scale of Detroit's 1943 race riot 24 years earlier.


title: 1967 Detroit riot

text: Governor George W. Romney ordered the Michigan Army National Guard into Detroit to help end the disturbance. President Lyndon B. Johnson sent in the United States Army's 82nd and 101st Airborne divisions. The riot resulted in 43 deaths, 1,189 injured, over 7,200 arrests, and more than 400 buildings destroyed.


title: 1967 Detroit riot

text: The scale of the riot was the worst in the United States since the 1863 New York City draft riots during the American Civil War, and it was not surpassed until the 1992 Los Angeles riots 25 years later.


title: 1967 Detroit riot

text: The riot was prominently featured in the news media, with live television coverage, extensive newspaper reporting, and extensive stories in "Time" and "Life" magazines. The staff of the "Detroit Free Press" won the 1968 Pulitzer Prize for general local reporting for its coverage.


title: 1967 Detroit riot

text: Canadian folk singer Gordon Lightfoot wrote and recorded "Black Day in July" recounting these events on his 1968 album "Did She Mention My Name?". The song was subsequently banned by radio stations in 30 American states. "Black Day in July" was later covered by The Tragically Hip on the 2003 anthology "Beautiful: A Tribute to Gordon Lightfoot".


title: 1967 Detroit riot

text: In the early 20th century, when African Americans migrated to Detroit in the Great Migration, the city experienced a rapidly increasing population and a shortage of housing. African Americans encountered strong discrimination in housing. Both racial covenants and unspoken agreements among whites kept black people out of certain neighborhoods and prevented most African Americans from buying their own homes. The presence of Ku Klux Klan members throughout Michigan furthered racial tensions and violence. Malcolm X's father, Earl Little, was killed in a streetcar accident in 1931, although it is alleged the Klan's Black Legion in East Lansing was involved. In addition, a system of redlining was instituted, which made it nearly impossible for black Detroiters to purchase a home in most areas of the city, effectively locking black residents into lower-quality neighborhoods. These discriminatory practices and the effects of the segregation that resulted from them contributed significantly to the racial tensions in the city before the riot. Segregation also encouraged harsher policing in African American neighborhoods, which escalated black Detroiters' frustrations leading up to the riot.


title: 1967 Detroit riot

text: Patterns of racial and ethnic segregation persisted through the mid-20th century. In 1956, mayor Orville Hubbard of Dearborn, part of Metro Detroit, boasted to the "Montgomery Advertiser" that "Negroes can't get in here...These people are so anti-colored, much more than you in Alabama."


title: 1967 Detroit riot

text: The election of Mayor Jerome Cavanagh in 1961 brought some reform to the police department, led by new Detroit Police Commissioner George Edwards. Detroit had acquired millions in federal funds through President Johnson's Great Society programs and invested them almost exclusively in the inner city, where poverty and social problems were concentrated. By the 1960s, many black people had advanced into better union and professional jobs. The city had a prosperous black middle class; higher-than-normal wages for unskilled black workers due to the success of the auto industry; two black Congressmen (half of the black Congressmen at the time); three black judges; two black members on the Detroit Board of Education; a housing commission that was forty percent black; and twelve black representatives representing Detroit in the Michigan legislature. The city had mature black neighborhoods such as Conant Gardens. In May 1967, the federal administration ranked housing for the black community in Detroit above that of Philadelphia, New York City, Chicago, and Cleveland. Nicholas Hood, the sole black member of the nine-member Detroit Common Council, praised the Cavanagh administration for its willingness to listen to concerns of the inner city. Weeks prior to the riot, Mayor Cavanagh had said that residents did not "need to throw a brick to communicate with City Hall."


title: 1967 Detroit riot

text: There were still signs of black disaffection, however; In 1964, Rosa Parks, who had moved to Detroit in the late fifties, told an interviewer: ""I don't feel a great deal of difference here [from Alabama]...Housing segregation is just as bad, and it seems more noticeable in the larger cities."" The improvements mostly benefited wealthier black Detroiters, and poor black Detroiters remained frustrated by the social conditions in Detroit. Despite the modest improvements described above, segregation, police brutality and racial tension were rampant in 1960s Detroit and played a large role in inciting the riot.


title: 1967 Detroit riot

text: The Detroit Police Department was administered directly by the Mayor. Prior to the riot, Mayor Cavanagh's appointees, George Edwards and Ray Girardin, worked for reform. Edwards tried to recruit and promote black police officers, but he refused to establish a civilian police review board, as African Americans had requested. In trying to discipline police officers accused of brutality, he turned the police department's rank-and-file against him. Many whites perceived his policies as "too soft on crime." The Community Relations Division of the Michigan Civil Rights Commission undertook a study in 1965 of the police, published in 1968. It claimed the "police system" was at fault for racism. The police system was blamed for recruiting "bigots" and reinforcing bigotry through the department's "value system." A survey conducted by President Johnson's Kerner Commission found that prior to the riot, 45 percent of police working in black neighborhoods were "extremely anti-Negro" and an additional 34 percent were "prejudiced."


title: 1967 Detroit riot

text: In 1967, 93% of the force was still white, although 30% of the city residents were black. Incidents of police brutality caused black residents to feel at risk. They resented many police officers who they felt talked down to them, addressing men as "boys" and women as "honey" and "baby." Police made street searches of groups of young men, and single women complained of being called prostitutes for simply walking on the street. The police frequently arrested people who did not have proper identification. The local press reported several questionable shootings and beatings of black citizens by officers in the years before 1967. After the riot, a "Detroit Free Press" survey showed that residents reported police brutality as the number one problem they faced in the period leading up to the riot.


title: 1967 Detroit riot

text: Black citizens complained that the police did not respond to their calls as quickly as to those of white citizens. They believed that the police profited from vice and other crime in black neighborhoods, and press accusations of corruption and connections to organized crime weakened their trust in the police. According to Sidney Fine, "the biggest complaint about vice in the ghetto was prostitution." The black community leadership thought the police did not do enough to curb white johns from exploiting local women. In the weeks leading up to the riot, police had started to work to curb prostitution along Twelfth Street. On July 1, a prostitute was killed, and rumors spread that the police had shot her. The police said that she was murdered by local pimps. Detroit police used "Big 4" or "Tac Squads," each made up of four police officers, to patrol Detroit neighborhoods, and such squads were used to combat soliciting.


title: 1967 Detroit riot

text: Black residents felt police raids of after-hours drinking clubs were racially biased actions. Since the 1920s, such clubs had become important parts of Detroit's social life for black citizens; although they started with Prohibition, they continued because of discrimination against black people in service at many Detroit bars, restaurants, and entertainment venues.


title: 1967 Detroit riot

text: In the postwar period, the city had lost nearly 150,000 jobs to the suburbs. Factors were a combination of changes in technology, increased automation, consolidation of the auto industry, taxation policies, the need for different kinds of manufacturing space, and the construction of the highway system that eased transportation. Major companies like Packard, Hudson, and Studebaker, as well as hundreds of smaller companies, went out of business. In the 1950s, the unemployment rate hovered near 10 percent. Between 1946 and 1956, GM spent $3.4 billion on new plants, Ford $2.5 billion, and Chrysler $700 million, opening a total of 25 auto plants, all in Detroit's suburbs. As a result, workers who could do so left Detroit for jobs in the suburbs. Other middle-class residents left the city for newer housing, in a pattern repeated nationwide. In the 1960s, the city lost about 10,000 residents per year to the suburbs. Detroit's population fell by 179,000 between 1950 and 1960, and by another 156,000 residents by 1970, which affected all its retail businesses and city services.


title: 1967 Detroit riot

text: By the time of the riot, unemployment among black men was more than double that among white men in Detroit. In the 1950s, 15.9 percent of blacks were unemployed, but only 6 percent of whites were unemployed. This was partially due to the union seniority system of the factories. Except for Ford, which hired a significant number of black workers for their factories, the other automakers did not hire black workers until World War II resulted in a labor shortage. With lower seniority, black workers were the first to be laid off in job cutbacks after the war. Moreover, black labor was "ghettoized" into the "most arduous, dangerous and unhealthy jobs."


title: 1967 Detroit riot

text: When the auto industry boomed again in the early 1960s, only Chrysler and the Cadillac Division of General Motors assembled vehicles in the city of Detroit. The black workers they hired got "the worst and most dangerous jobs: the foundry and the body shop."


title: 1967 Detroit riot

text: A prosperous, black educated class had developed in traditional professions such as social work, ministry, medicine, and nursing. Many other black citizens working outside manufacturing were relegated to service industries as waiters, porters, or janitors. Many black women were limited to work in domestic service. Certain business sectors were known to discriminate against hiring black workers, even at entry-level positions. It took picketing by Arthur Johnson and the Detroit chapter of the NAACP before First Federal Bank hired their first black tellers and clerks.


title: 1967 Detroit riot

text: Housing in Detroit had been a major problem due to the industrial boom that started in the early 20th century. Several urban renewal projects after World War II, intended to improve housing, dramatically changed neighborhood boundaries and ethnic composition. Affordability for industrial workers and the sheer number of new people in the city resulted in a housing shortage, ultimately fostering the need to establish federal loan systems and invest in public housing, especially for minority populations. Detroit undertook a series of urban renewal projects that disproportionately affected black people, who occupied some of the oldest housing.


title: 1967 Detroit riot

text: Racial discrimination in housing was federally enforced by redlining and restrictive covenants in the mid-20th century. They played an important role in segregating Detroit and escalating racial tensions in the city. The Home Owners' Loan Corporation was in charge of assigning ratings of "A" (green) through "D" (red) to all of the neighborhoods in major U.S. cities based on the conditions of the buildings, the infrastructure and most importantly, the racial composition of the area. Residents of a neighborhood with a "C" or "D" rating struggled to get loans, and almost all neighborhoods with any African American population were rated "D", effectively segregating the city by race. This effectively limited options for African Americans to purchase houses outside of these areas, or acquire resources to repair their already damaged homes in these areas. In fact, only 0.8% of all new construction in the city was available to African Americans. Black Bottom and Paradise Valley (located on Detroit's lower east side, south of Gratiot) were examples of African-American neighborhoods that formed as a result of these government restrictions.


title: 1967 Detroit riot

text: Examples of city projects for housing include the massive Gratiot Redevelopment Project, planned as early as 1946. It was planned eventually to cover a site on the lower east side that included Hastings Street — the center of Paradise Valley. Other public housing projects also resulted in more tension between white and black people in the city. Although it seemed positive for working class individuals, the negative effects can still be felt today. Projects like Sojurner Truth were erected in 1941 to account for the unfair bias against African Americans in their housing search. However, it ended up concentrating the African Americans in areas where city whites did not want them, only furthering the racial tension in the city.


title: 1967 Detroit riot

text: The city's goals were to “arrest the exodus of business from the central city, to convert slum property to better housing, and to enlarge the city's tax base." Bolstered by successive federal legislation, including the 1941, 1949, 1950, 1954 versions of the "Housing Act" and its amendments through the 1960s, the city acquired funds to develop the Detroit Medical Center complex, Lafayette Park, Central Business District Project One, and the Chrysler Freeway, by appropriating land and "clearing slums." Money was included for replacement housing in the legislation, but the goal of urban renewal was to physically reshape the city; its social effects on neighborhoods was not well understood. As older neighborhoods were demolished, black people, and people of every color from Detroit's skid row, moved to areas north of Black Bottom along Grand Boulevard, but especially to the west side of Woodward, along Grand Boulevard and ultimately the 12th Street neighborhood. As Ze'ev Chafets wrote in "Devil's Night and Other True Tales of Detroit" (1990's), in the 1950s the area around 12th Street rapidly changed from a community of ethnic Jews to a predominantly black community, an example of white flight. Jewish residents had moved to the suburbs for newer housing, but they often retained business or property interests in their old community. Thus, many of the blacks who moved to the 12th Street area rented from absentee landlords and shopped in businesses run by suburbanites. Crime rates rose in the 12th Street area.


title: 1967 Detroit riot

text: By 1967, distinct neighborhood boundaries were known, whether visible (as the case on Eight Mile and Wyoming), or invisible (as the case of Dequindre Road). With white and black people culturally and physically separated, racial tensions were high in the city. As a result, African American neighborhoods were overrun, high in density, and often poor in health quality. For example, the neighborhood around 12th Street had a population density that was twice the city average. After the riot, respondents to a "Detroit Free Press" poll listed poor housing as the second most important issue leading up to the riot, behind police brutality.


title: 1967 Detroit riot

text: Detroit Public Schools suffered from underfunding and racial discrimination before the riots. Underfunding was a function of a decreasing tax base as the population shrank while the numbers of students rose. From 1962 to 1966, enrollment grew from 283,811 to 294,653, but the loss of tax base made less funding available. At the same time, middle-class families were leaving the district, and the number of low-scoring and economically disadvantaged students, mostly black, were increasing. In 1966–67, the funding per pupil in Detroit was $193 compared to $225 per pupil in the suburbs. Exacerbating this inequity were the challenges in educating disadvantaged students. The Detroit Board of Education estimated it cost twice as much to educate a "ghetto child properly as to educate a suburban child." According to Michigan law in 1967, class sizes could not exceed thirty-five students, but in inner city schools they did, sometimes swelling to forty students per teacher. To have the same teacher/student ratio as the rest of the state, Detroit would have to hire 1,650 more teachers for the 1966–67 school year.


title: 1967 Detroit riot

text: In 1959, the Detroit School Board passed a bylaw banning discrimination in all school operations and activities. From 1962 to 1966, black organizations continued to work to improve the quality of education of black students. Issues included class size, school boundaries, and how white teachers treated black students. The Citizens Advisory Committee on Equal Educational Opportunities reported a pattern of discrimination in the assignment of teachers and principals in Detroit schools. It also found "grave discrimination" in employment, and in training opportunities in apprenticeship programs. It was dissatisfied with the rate of desegregation in attendance boundaries. The school board accepted the recommendations made by the committee, but faced increasing community pressure. The NAACP demanded affirmative action hiring of school personnel and increased desegregation through an "open schools" policy. Foreshadowing the break between black civil rights groups and black nationalists after the riot, a community group led by Rev. Albert Cleage, Group of Advanced Leadership (GOAL), emphasized changes in textbooks and classroom curriculum as opposed to integration. Cleage wanted black teachers to teach black students in black studies, as opposed to integrated classrooms where all students were held to the same academic standards.


title: 1967 Detroit riot

text: In April and May 1966, a student protest at Detroit Northern High School made headlines throughout the city. Northern was 98% Black and had substandard academic testing scores. A student newspaper article, censored by the administration, claimed teachers and the principal "taught down" to blacks and used social promotion to graduate kids without educating them. Students walked out and set up a temporary "Freedom School" in a neighborhood church, which was staffed by many volunteer Wayne State University faculty. By May sympathy strikes were planned at Eastern, and Rev. Albert Cleage had taken up the cause. When the school board voted to remove the principal and vice principal, as well as the single police officer assigned to Northern, whites regarded the board's actions as capitulation to "threats" and were outraged the "students were running the school". City residents voted against a school-tax increase.


title: 1967 Detroit riot

text: Under the Cavanagh administration, the school board created a Community Relations Division at the deputy superintendent level. Arthur L. Johns, the former head of the Detroit chapter of the NAACP, was hired in 1966 to advance community involvement in schools, and improve "intergroup relations and affirmative action." Black dominated schools in the city continued to be overcrowded as well as underfunded.


title: 1967 Detroit riot

text: Customer surveys published by the "Detroit Free Press" indicated that blacks were disproportionately unhappy with the way store owners treated them compared to whites. In stores serving black neighborhoods, owners engaged in "sharp and unethical credit practices" and were "discourteous if not abusive to their customers." The NAACP, Trade Union Leadership Council (TULC), and Congress of Racial Equality (CORE) all took up this issue with the Cavanagh administration before the riot. In 1968, the Archdiocese of Detroit published one of the largest shopper surveys in American history. It found that the inner-city shopper paid 20% more for food and groceries than the suburbanite. Some of the differences were due to economies of scale in larger suburban stores, as well as ease in transportation and delivery of goods.


title: 1967 Detroit riot

text: Shortly after the Detroit riot, Mayor Jerome Cavanagh lashed out at the "profiteering" of merchants and asked the city council to pass an anti-gouging ordinance.


title: 1967 Detroit riot

text: The crimes reported to police included looting, arson, and sniping, and took place in many different areas of Detroit: on the west side of Woodward Avenue, extending from the 12th Street neighborhood to Grand River Avenue and as far south as Michigan Avenue and Trumbull, near Tiger Stadium. East of Woodward, the area around East Grand Boulevard, which goes east/west then north–south to Belle Isle, was involved. However, the entire city was affected between Sunday, July 23, and Thursday, July 27.


title: 1967 Detroit riot

text: In the early hours of Sunday (3:45 a.m.), July 23, 1967, Detroit Police Department (DPD) officers raided an unlicensed weekend drinking club (known locally as a blind pig) in the office of the United Community League for Civic Action, above the Economy Printing Company, at 9125 12th Street. They expected a few revelers inside, but instead found a party of 82 people celebrating the return of two local GIs from the Vietnam War. The police decided to arrest everyone present. While they were arranging for transportation, a sizable crowd of onlookers gathered on the street, having witnessed the raid. Later, in a memoir, William Walter Scott III, a doorman whose father was running the raided blind pig, took responsibility for starting the riot by inciting the crowd and throwing a bottle at a police officer.


title: 1967 Detroit riot

text: After the DPD left, the crowd began looting an adjacent clothing store. Shortly thereafter, full-scale looting began throughout the neighborhood. The Michigan State Police, Wayne County Sheriff's Department, and the Michigan Army National Guard were alerted, but because it was Sunday, it took hours for Police Commissioner Ray Girardin to assemble sufficient manpower. Meanwhile, witnesses described seeing a "carnival atmosphere" on 12th Street. The DPD, inadequate in number and wrongly believing that the rioting would soon expire, just stood there and watched. Police did not make their first arrest until 7 a.m., three hours after the raid on the blind pig. To the east, on Chene Street, reports said the crowd was of mixed composition. The pastor of Grace Episcopal Church along 12th Street reported that he saw a "gleefulness in throwing stuff and getting stuff out of buildings". The police conducted several sweeps along 12th Street, which proved ineffective because of the unexpectedly large numbers of people outside. The first major fire broke mid-afternoon in a grocery store at the corner of 12th Street and Atkinson. The crowd prevented firefighters from extinguishing it, and soon more smoke filled the skyline.


title: 1967 Detroit riot

text: The local news media initially avoided reporting on the disturbance so as not to inspire copy-cat violence, but the rioting started to expand to other parts of the city, including looting of retail and grocery stores elsewhere. By Sunday afternoon, news had spread, and people attending events such as a Fox Theater Motown revue and Detroit Tigers baseball game were warned to avoid certain areas of the city. Motown's Martha Reeves was on stage at the Fox, singing "Jimmy Mack," and was asked to tell people to leave quietly, as there was trouble outside. After the game, Tigers left fielder Willie Horton, a Detroit resident who had grown up not far from 12th Street, drove to the riot area and stood on a car in the middle of the crowd while still in his baseball uniform. Despite Horton's impassioned pleas, he could not calm the crowd.


title: 1967 Detroit riot

text: Mayor Jerome Cavanagh stated that the situation was "critical" but not yet "out of control." At 7:45 p.m. that first (Sunday) night, Cavanagh enacted a citywide 9:00 p.m. – 5:30 a.m. curfew, prohibited sales of alcohol and firearms, and informally curtailed business activity in recognition of the serious civil unrest engulfing sections of the city. A number of adjoining communities also enacted curfews. There was significant white participation in the rioting and looting, raising questions as to whether the event fits into the classical race riot category.


title: 1967 Detroit riot

text: Michigan State Police and the Wayne County Sheriff's Department were called in to Detroit to assist an overwhelmed Detroit police force. As the violence spread, the police began to make numerous arrests to clear rioters off the streets, housing the detainees in makeshift jails. Beginning Monday, people were detained without being brought to Recorder's Court for arraignment. Some gave false names, making the process of identifying those arrested difficult because of the need to take and check fingerprints. Windsor Police were asked to help check fingerprints.


title: 1967 Detroit riot

text: Police began to take pictures of looters arrested, the arresting officer, and the stolen goods, to speed up the process and postpone the paperwork. More than eighty percent of those arrested were black. About twelve percent were women. Michigan National Guardsmen were not authorized to arrest people, so state troopers and police officers made all arrests without discriminating between civilians and criminals.


title: 1967 Detroit riot

text: Michigan Governor George Romney and President Lyndon B. Johnson initially disagreed about the legality of sending in federal troops. Johnson said he could not send federal troops in without Romney's declaring a "state of insurrection", to meet compliance with the Insurrection Act.


title: 1967 Detroit riot

text: As the historian Sidney Fine details in "Violence in the Model City", partisan political issues complicated decisions, as is common in crisis. George Romney was expected to run for the Republican presidential nomination in 1968, and President Johnson, a Democrat, did not want to commit troops solely on Romney's direction. Added to this was Mayor Jerome Cavanagh's own political and personal clash with Romney. Cavanagh, a young Irish Catholic Democrat who had cultivated harmonious relations with black leaders, both inside and outside the city, was initially reluctant to ask Romney, a Republican, for assistance.


title: 1967 Detroit riot

text: The violence escalated throughout Monday, resulting in some 483 fires, 231 incidents reported per hour, and 1,800 arrests. Looting and arson were widespread. Black-owned businesses were not spared. One of the first stores looted in Detroit was Hardy's drug store, owned by black people and known for filling prescriptions on credit. Detroit's leading black-owned women's clothing store was burned, as was one of the city's best-loved black restaurants. In the wake of the riots, a black merchant said, "you were going to get looted no matter what color you were." Firefighters of the Detroit Fire Department who were attempting to fight the fires were shot at by rioters. During the riots, 2,498 rifles and 38 handguns were stolen from local stores. It was obvious that the City of Detroit, Wayne County, and State of Michigan forces were unable to restore order.


title: 1967 Detroit riot

text: On Monday, U.S. Representative John Conyers (D-Michigan), who was against federal troop deployment, attempted to ease tensions by driving along 12th Street with a loudspeaker asking people to return to their homes. Reportedly, Conyers stood on the hood of the car and shouted through a bullhorn, "We're with you! But, please! This is not the way to do things! Please go back to your homes!" But the crowd refused to listen. Conyers' car was pelted with rocks and bottles.


title: 1967 Detroit riot

text: Shortly before midnight on Monday, July 24, President Johnson authorized the use of federal troops in compliance with the Insurrection Act of 1807, which authorizes the President to call in armed forces to fight an insurrection in any state against the government. This gave Detroit the distinction of being the only domestic American city to have been occupied by federal troops three times. The United States Army's 82nd Airborne Division and 101st Airborne Division had earlier been positioned at nearby Selfridge Air Force Base in suburban Macomb County. Starting at 1:30a.m. on Tuesday, July 25, some 8,000 Michigan Army National Guardsmen were deployed to quell the disorder. Later, their number would be augmented with 4,700 paratroopers from both the 82nd and 101st Airborne Divisions, and 360 Michigan State Police officers.


title: 1967 Detroit riot

text: Chaos continued; the police were overworked and tired. Detroit Police were found to have committed many acts of abuse against both blacks and whites who were in their custody.


title: 1967 Detroit riot

text: Although only 26 of the over 7,000 arrests involved snipers, and not one person accused of sniping was successfully prosecuted, the fear of snipers precipitated many police searches. The "searching for weapons" caused many homes and vehicles to be scrutinized. Curfew violations were also common sparks to police brutality. The Detroit Police's 10th Precinct routinely abused prisoners; as mug shots later proved, many injuries came after booking. Women were stripped and fondled while officers took pictures. White landlords from New York visiting their building were arrested after a sniper call and beaten so horribly that "their testicles were still black and blue two weeks after the incident."


title: 1967 Detroit riot

text: A four-year-old girl named Tanya Blanding was shot and killed during the riot while she huddled in the living room of her second-floor apartment, a few steps from the intersection of 12th and Euclid, in the heart of the original riot area (precinct 10).