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49-563: The RPG-2 offered better range and armor penetration, making it useful against late and post-World War II tanks, in contrast to the RPG-1 that had only marginal utility. The basic design and layout was further upgraded to produce the ubiquitous RPG-7 . Studying German and US anti-tank rocket designs, in 1944 the Soviets began development of the RPG-1 with the goal of combining the best features of

98-617: A revision in November 2018 that defines the kilogram by defining the Planck constant to be exactly 6.626 070 15 × 10  kg⋅m ⋅s , effectively defining the kilogram in terms of the second and the metre. The new definition took effect on 20 May 2019. Prior to the redefinition, the kilogram and several other SI units based on the kilogram were defined by a man-made metal artifact: the Kilogramme des Archives from 1799 to 1889, and

147-474: A "small strip powder charge" that serves to propel the grenade out of the launcher; the sustainer motor then ignites and propels the grenade for the next few seconds, giving it a top speed of 294 m/s (960 ft/s). The TRADOC bulletin provides anecdotal commentary that the RPG-7 has been fired from within buildings, which agrees with the two-stage design. It is stated that only a 2 metres (6.6 feet) standoff to

196-474: A cloud of light grey-blue smoke that can give away the position of the shooter. The rocket motor ignites after 10 m (33 ft) and sustains flight out to 500 m (1,600 ft) at a maximum velocity of 295 m/s (970 ft/s). The grenade is stabilized by two sets of fins that deploy in-flight: one large set on the stabilizer pipe to maintain direction and a smaller rear set to induce rotation. The grenade can fly up to 1,100 m (3,600 ft);

245-567: A detector, together weighing (with batteries) 6 kg (13 lb 4 oz). The NSP-2 was usable out to 150–200 metres (490–660 ft) under good conditions. When fitted with the NSP-2, the launcher became known as the RPG-2N. Widely distributed to allies of the Soviet Union, it was also produced under license by China, North Vietnam and North Korea . Used against the U.S. military in

294-719: A muzzle velocity of 84 m/s (280 ft/s) and could penetrate armor up to 180 mm (7.1 in) thick. RPG-7 The RPG-7 is a portable, reusable, unguided, shoulder-launched , anti-tank , rocket launcher . The RPG-7 and its predecessor, the RPG-2 , were designed by the Soviet Union , and are now manufactured by the Russian company Bazalt . The weapon has the GRAU index (Russian armed forces index) 6G3 . The ruggedness, simplicity, low cost, and effectiveness of

343-434: A rear obstruction is needed for use inside rooms or fortifications. The fins not only provide drag stabilization, but are designed to impart a slow rotation to the grenade. Due to the configuration of the RPG-7 sustainer/warhead section, it responds counter-intuitively to crosswinds. A crosswind will tend to exert pressure on the stabilizing fins, causing the projectile to turn into the wind ( see Weathervane effect ). While

392-480: A second tube around this carrying the fins. When the round was inserted into the launcher, the second tube was outside the launcher tube, requiring the front of the launcher to be free of any fittings. The PG-2 replaced the fins with small metal leaves attached to the inner tube, and eliminated the outer tube found on the PG-1. This allowed the entire propellant section to be inserted into the launcher, which in turn allowed

441-447: A weight measurement to a mass and therefore require precise measurement of the strength of gravity in laboratories ( gravimetry ). All approaches would have precisely fixed one or more constants of nature at a defined value. Because an SI unit may not have multiple prefixes (see SI prefix ), prefixes are added to gram , rather than the base unit kilogram , which already has a prefix as part of its name. For instance, one-millionth of

490-613: A written specification. At the 94th Meeting of the CIPM in 2005, it was recommended that the same be done with the kilogram. In October 2010, the CIPM voted to submit a resolution for consideration at the General Conference on Weights and Measures (CGPM), to "take note of an intention" that the kilogram be defined in terms of the Planck constant , h (which has dimensions of energy times time, thus mass × length / time) together with other physical constants. This resolution

539-517: Is colloquially abbreviated to kilo . The kilogram is an SI base unit , defined ultimately in terms of three defining constants of the SI, namely a specific transition frequency of Cs, the speed of light, and the Planck constant. A properly equipped metrology laboratory can calibrate a mass measurement instrument such as a Kibble balance as a primary standard for the kilogram mass. The kilogram

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588-655: Is described as "a common informal name" on Russ Rowlett's Dictionary of Units of Measurement. When the United States Congress gave the metric system legal status in 1866, it permitted the use of the word kilo as an alternative to the word kilogram , but in 1990 revoked the status of the word kilo . The SI system was introduced in 1960 and in 1970 the BIPM started publishing the SI Brochure , which contains all relevant decisions and recommendations by

637-516: Is the only base SI unit with an SI prefix ( kilo ) as part of its name. The word kilogramme or kilogram is derived from the French kilogramme , which itself was a learned coinage, prefixing the Greek stem of χίλιοι khilioi "a thousand" to gramma , a Late Latin term for "a small weight", itself from Greek γράμμα . The word kilogramme was written into French law in 1795, in

686-682: Is warhead dependent and ranges from 300–600 mm (12–24 in) of RHA ; one warhead, the PG-7VR, is a 'tandem charge' device, used to defeat reactive armor with a single shot. The Russian Ministry of Defense said in December 2023 that it has modified the RPG-7V grenade launcher in order to shoot 82-mm mines. Current production ammunition for the RPG-7V2 consists of four main types: Other warhead variants include: Manufacturer specifications for

735-657: The CGPM concerning units. The SI Brochure states that "It is not permissible to use abbreviations for unit symbols or unit names ...". For use with east Asian character sets, the SI symbol is encoded as a single Unicode character, U+338F ㎏ SQUARE KG in the CJK Compatibility block. The replacement of the International Prototype of the Kilogram (IPK) as the primary standard

784-540: The Decree of 18 Germinal , which revised the provisional system of units introduced by the French National Convention two years earlier, where the gravet had been defined as weight ( poids ) of a cubic centimetre of water, equal to 1/1000 of a grave . In the decree of 1795, the term gramme thus replaced gravet , and kilogramme replaced grave . The French spelling

833-409: The Planck constant h to be 6.626 070 15 × 10 when expressed in the unit J⋅s, which is equal to kg⋅m ⋅s , where the metre and the second are defined in terms of c and Δ ν Cs . Defined in term of those units, the kg is formulated as: This definition is generally consistent with previous definitions: the mass remains within 30 ppm of the mass of one litre of water. The kilogram

882-453: The RPG-7V2 , capable of firing standard and dual high-explosive anti-tank (HEAT) rounds , high explosive / fragmentation , and thermobaric warheads , with a UP-7V sighting device fitted (used in tandem with the standard 2.7× PGO-7 optical sight ) to allow the use of extended range ammunition. The RPG-7D3 is the equivalent paratrooper model. Both the RPG-7V2 and RPG-7D3 were adopted by

931-546: The Russian Ground Forces in 2001. The launcher is reloadable and based around a steel tube, 40 mm (1.6 in) in diameter, 950 mm (37 in) long, and weighing 7 kg (15 lb). The middle of the tube is wood wrapped to protect the user from heat and the end is flared. Sighting is usually optical with a back-up iron sight , and passive infrared and night sights are also available. The launchers designated RPG-7N1 and RPG-7DN1 can thus mount

980-571: The Vietnam War , its Vietnamese variants were called the B40 ( Ba Do Ka - "Bazooka 40mm") and B50 . B50 was B40 using Chinese Type 50 HEAT warhead (Chinese version of PG-2). The RPG-2 anti tank grenade launcher is a simple 40 millimeter steel tube into which the PG-2 grenade is fitted. The tailboom of the grenade inserts into the launcher. The diameter of the PG-2 warhead is 80mm. The center section of

1029-523: The first and second Chechen wars , the Chechen Republic of Ichkeria used RPG-7s which they had captured from Soviet bases and used them against Russian armored columns. During the first war, Russians may have lost 100 tanks and 250 armoured fighting vehicles (AFVs) in Grozny. The Chechens were able to knock out T-72s with three or four RPG-7 hits. Against T-72s with explosive reactive armor ,

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1078-505: The fuze sets the maximum range, usually 920 m (3,020 ft). According to the United States Army Training and Doctrine Command (TRADOC) Bulletin 3u (1977) Soviet RPG-7 Antitank Grenade Launcher—Capabilities and Countermeasures , the RPG-7 munition has two sections: a "booster" section and a "warhead and sustainer motor" section. These must be assembled into the ready-to-use grenade. The booster consists of

1127-459: The Chechens fired an RPG in close range (within 50 m (160 ft)) to detonate the armor and then followed this with RPG hits on the now exposed point of the tank, also from close range. The RPG-7 was also effective against AFVs, buildings and personnel. The PG-7VR has been used by Iraqi insurgents . On 28 August 2003, it achieved a mobility kill against an American M1 Abrams hitting

1176-588: The French word kilo , a shortening of kilogramme , was imported into the English language where it has been used to mean both kilogram and kilometre. While kilo as an alternative is acceptable, to The Economist for example, the Canadian government's Termium Plus system states that "SI (International System of Units) usage, followed in scientific and technical writing" does not allow its usage and it

1225-534: The German Panzerfaust single shot recoilless weapon with the US Bazooka rocket launcher. Propelled by a 30 mm cartridge, the 70 mm (2.8 in) high-explosive anti-tank (HEAT) shaped charge round could penetrate about 150 mm (5.9 in) of homogeneous armour. Early testing revealed several minor problems, but, by the time these were being solved, 150 mm of penetration

1274-465: The IPK from 1889 to 2019. In 1960, the metre , previously similarly having been defined with reference to a single platinum-iridium bar with two marks on it, was redefined in terms of an invariant physical constant (the wavelength of a particular emission of light emitted by krypton , and later the speed of light ) so that the standard can be independently reproduced in different laboratories by following

1323-458: The PG-2 high-explosive anti-tank (HEAT), was used in the RPG-2. The propellant , consisting of granulated powder was in a rolled cardboard case treated with wax that had to be attached to the grenade before loading. Once attached to the propellant charge, the grenade was inserted into the smooth-bore launcher from the front. A tab on the body of the grenade indexes in a notch cut in the tube so that

1372-470: The RPG-7 has made it the most widely used anti-armor weapon in the world. Currently around 40 countries use the weapon; it is manufactured in several variants by nine countries. It is popular with irregular and guerrilla forces . Widely produced, the most commonly seen major variations are the RPG-7D (десантник – desantnik – paratrooper ) model, which can be broken into two parts for easier carrying; and

1421-460: The RPG-7V1. 750 mm (30 in) RHA (without reactive armor ) A 1976 U.S. Army evaluation of the weapon gave the hit probabilities on a 5-by-2.5-metre (16.4 ft × 8.2 ft) panel moving sideways at 4 m/s (13 ft/s). Crosswinds cause additional issues as the round steers into the wind; in an 11 km/h (6.8 mph) wind, firing at a stationary tank sized target,

1470-585: The Soviet Army's infantry squads in 1954. Although the RPG-2 could be operated by one man, standard military practice called for a two-man crew: a grenadier carrying a Stechkin APS , the launcher and a purpose-built backpack containing three grenades and an assistant armed with a rifle and carrying another three-grenade backpack. In 1957, the launcher was adapted to be able to mount the NSP-2 infrared (IR) night-sight system, which consisted of an IR spotlight and

1519-412: The frontal armor of all but the very heaviest tanks, and the side and rear armor of any tank. The larger cartridge gave the PG-2 warhead slightly better practical range as well, about 150 m (490 ft) against stationary targets. The design of the PG-2 differed considerably from that of the PG-1 of the RPG-1. The rear section of the PG-1 consisted of a central tube holding the propelling charge, and

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1568-828: The gunner cannot expect to get a first-round hit more than 50% of the time at 180 m (590 ft). The RPG-7 was first used in 1967 by Egypt during the Six-Day War , and by the Viet Cong during the Vietnam War , but it did not see widespread usage in Vietnam until the following year. The RPG-7 was used by the Provisional Irish Republican Army in Northern Ireland from 1969 to 2005, most notably in Lurgan , County Armagh, where it

1617-580: The left side hull next to the forward section of the engine compartment. During the War in Afghanistan (2001–2021) , several M1A2 Abrams were temporarily disabled by RPG-7 hits. Kilogram The kilogram (also spelled kilogramme ) is the base unit of mass in the International System of Units (SI), having the unit symbol kg . 'Kilogram' means 'one thousand grams ' and

1666-467: The lighter Chinese Type 69 RPG . DIO of Iran manufactures RPG-7s with olive green handguards, H&K style pistol grips, and a commando variant. The RPG-7 was first delivered to the Soviet Army in 1961 and deployed at the squad level. It replaced the RPG-2, having clearly out-performed the intermediate RPG-4 design during testing. The current model produced by the Russian Federation is

1715-471: The multi-purpose night vision scope 1PN51 and the launchers designated RPG-7N2 and RPG-7DN2 can mount the multi-purpose night vision scope 1PN58 . As with similar weapons, the grenade protrudes from the launch tubes. It is 40–105 mm (1.6–4.1 in) in diameter and weighs between 2 kg (4.4 lb) and 4.5 kg (9.9 lb). It is launched by a gunpowder booster charge, giving it an initial speed of 115 m/s (380 ft/s), and creating

1764-455: The post-war period handed to the Ministry of Agriculture to help design farm equipment. The main difference in performance between the two were due to size. The RPG-2 used a custom designed 40 mm (1.6 in) cartridge to provide much greater power, and the warhead enlarged to 80 mm (3.1 in). This improved penetration to 180 mm (7.1 in), which allowed it to penetrate

1813-467: The primer in the propelling charge aligns with the firing pin and hammer mechanism. To fire the RPG-2, the grenadier cocked an external hammer with his thumb, aimed, and pulled the trigger to fire. Upon launch, six stabilizer fins unfolded from the grenade. The weapon was accurate, depending on the soldier's experience, against stationary targets up to 150 m (490 ft) and against moving targets at ranges of less than 100 m (330 ft). It had

1862-500: The reproducible production of new, kilogram-mass prototypes on demand (albeit with extraordinary effort) using measurement techniques and material properties that are ultimately based on, or traceable to, physical constants. Others were based on devices that measured either the acceleration or weight of hand-tuned kilogram test masses and that expressed their magnitudes in electrical terms via special components that permit traceability to physical constants. All approaches depend on converting

1911-441: The rocket motor is still burning, this will cause the flight path to curve into the wind. The TRADOC bulletin explains aiming difficulties for more distant moving targets in crosswinds at some length. The RPG-7 can fire a variety of warheads for anti-armor (HEAT, PG-Protivotankovaya Granata) or anti-personnel ( HE , OG-Oskolochnaya Granata) purposes, usually fitting with an impact (PIBD) and a 4.5 second fuze . Armor penetration

1960-404: The sights and trigger assembly to be mounted right at the front of the launcher. This slightly reduced the length compared to the RPG-1, made the entire assembly more robust, and allowed the use of conventional fore-and-aft sights. The new design was such an improvement on the earlier design that development of the RPG-1 ended in 1948. The first production versions of the RPG-2 entered service with

2009-405: The standard of the unit of mass for the metric system and remained so for 130 years, before the current standard was adopted in 2019 . The kilogram is defined in terms of three defining constants: The formal definition according to the General Conference on Weights and Measures (CGPM) is: The kilogram, symbol kg, is the SI unit of mass. It is defined by taking the fixed numerical value of

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2058-405: The tube has a thin wooden covering to protect the user from the heat generated by the grenade launch. The wooden covering also makes using the weapon in extreme cold conditions easier. The total length of the weapon with a grenade fitted was 120 centimeters (47 inches) and it weighed 4.48 kilograms (9.8 pounds ). Only a simple iron sight was provided for aiming. Only one type of grenade,

2107-618: Was accepted by the 24th conference of the CGPM in October 2011 and further discussed at the 25th conference in 2014. Although the Committee recognised that significant progress had been made, they concluded that the data did not yet appear sufficiently robust to adopt the revised definition, and that work should continue to enable the adoption at the 26th meeting, scheduled for 2018. Such a definition would theoretically permit any apparatus that

2156-592: Was adopted in Great Britain when the word was used for the first time in English in 1795, with the spelling kilogram being adopted in the United States. In the United Kingdom both spellings are used, with "kilogram" having become by far the more common. UK law regulating the units to be used when trading by weight or measure does not prevent the use of either spelling. In the 19th century

2205-410: Was capable of delineating the kilogram in terms of the Planck constant to be used as long as it possessed sufficient precision, accuracy and stability. The Kibble balance is one way to do this. As part of this project, a variety of very different technologies and approaches were considered and explored over many years. Some of these approaches were based on equipment and procedures that would enable

2254-525: Was motivated by evidence accumulated over a long period of time that the mass of the IPK and its replicas had been changing; the IPK had diverged from its replicas by approximately 50 micrograms since their manufacture late in the 19th century. This led to several competing efforts to develop measurement technology precise enough to warrant replacing the kilogram artefact with a definition based directly on physical fundamental constants. The International Committee for Weights and Measures (CIPM) approved

2303-605: Was no longer considered effective against modern tanks, even late-war designs like the Panther . The warhead was already straining the abilities of the cartridge and its range was already considered too low. Modifications to improve this began, but in 1947 the RPG-2 program began as a parallel project. Development of the RPG-2 was carried out by the GSKB-30 design bureau, originally part of the Commissariat for Munitions , but in

2352-474: Was originally defined in 1795 during the French Revolution as the mass of one litre of water . The current definition of a kilogram agrees with this original definition to within 30 parts per million . In 1799, the platinum Kilogramme des Archives replaced it as the standard of mass. In 1889, a cylinder composed of platinum–iridium , the International Prototype of the Kilogram (IPK), became

2401-580: Was used against British Army observation posts and the towering military base at Kitchen Hill in the town. The IRA also used them in Catholic areas of West Belfast against British Army armoured personnel carriers (APCs) and Army forward operating bases (FOBs). Beechmount Avenue in Belfast became known as "RPG Avenue" after attacks on British troops. In Mogadishu, Somalia, RPG-7s were used to down two U.S. Army Black Hawk helicopters in 1993. During

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