Rocket propelled grenade

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An RPG is a hand-held, shoulder-launched antitank weapon capable of firing an unguided rocket containing an explosive warhead. Most modern main battle tanks (MBTs) are largely immune to unguided anti-tank weapons, due to advances in armor design, requiring more precise aiming to hit weak spots. However, RPGs are still used very effectively against light-skinned vehicles such as armoured personnel carriers (APCs) or unarmored wheeled vehicles, as well as against buildings and bunkers. They can still be a threat to an MBT under certain tactical conditions (see below).

RPG stands for "handheld antitank grenade-launcher" in Russian: Ruchnoy Protivotankovy Granatomyot (Ручной противотанковый гранатомёт, РПГ). The English translation of this, "Rocket-Propelled Grenade" — backformed from the acronym RPG — is technically inaccurate, as most western armies do not use this term to describe these weapons.

1 Description
2 Warheads
3 Tactics
4 History
5 See also
6 External links

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Description

An RPG is composed of two main parts, the launcher and the rocket/warhead. Some types of RPGs are single-use disposable units similar to the U.S. M72 LAW; others are reloadable, for example, the Soviet RPG-7. The most common types of warheads are high explosive (HE) or high explosive anti-tank (HEAT) rounds. These warheads are affixed to a rocket motor, and stabilized in flight with fins.

The weapon is usually made from inexpensive stamped sheet metal or die-cast aluminium, fiberglass, or zinc. This reduces cost and weight, allowing the weapon to be distributed in even the poorest countries to infantrymen who usually must march to their objectives. In all common man-portable RPG systems the launcher rests on the operator's shoulder while he aims through an attached optical sight. The rear of the launcher is open to allow the rocket exhaust to vent. Firing is accomplished with a trigger mechanism. RPG systems (such as the RPG-7), which use a re-usable launcher, are heavier and more robust than single-use systems. This is due to the higher level of durability required to withstand the stresses of repeated firings.

In an RPG, the launcher permits the rocket motor exhaust to create an over-pressure within the tube. This over-pressure allows the warhead to obtain a speed greater than that which could be obtained from the specific impulse of the rocket motor. This high speed is necessary to allow the rocket to have enough momentum to be stable in flight, without continuing to burn past the forward lip of the launcher (which would be quite dangerous to the operator). This is not meant to imply that an RPG is a cannon, as the smaller over-pressure (compared to a cannon or a rifle) being used to boost the speed of the warhead, is not completely contained and creates the thrust.

The high-temperature rocket exhaust is hazardous 15 to 20 metres to the rear of an RPG launcher. The launcher must be cleaned periodically, as built-up residue will result in an excess of over-pressure, causing the sight to be driven into the operator's eye when the rocket is fired. Blindness in one eye often results.

All RPGs are similar in concept, however there are significant differences in their operation.

In the RPG-7, the warhead is loaded into the front of the launcher. Pulling the trigger strikes a percussion cap. The cap ignites a solid-fuel rocket. The rocket propels the 85 mm warhead forward without significant recoil. As the warhead emerges from the launcher, fins spring out from the base of the rocket tube, stabilizing the warhead's flight.

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Warheads

The HE (grenade) warhead is a general-purpose explosive warhead for use against unarmored targets such as infantry, unarmored wheeled vehicles and fixed positions. The HE warhead detonates upon impact. The warhead case and charge generate moderate amounts of shrapnel.

The HEAT (anti-tank) round is a standard shaped charge warhead, similar in concept to those used in tank cannon rounds. In this type of warhead, the shape of the explosive material within the warhead focuses the explosive energy on a copper (or similar metal) lining. This crushes the metal lining and propels some of it forward at a very high velocity. The resulting narrow jet of metal can punch through Rolled Homogeneous Armor (RHA) used in many armored vehicles including some types of main battle tanks. Although the warhead on RPG systems is too small to penetrate the main armor of most modern battle tanks, it is still capable of secondary damage to vulnerable systems (especially sights, tracks, rear and roof of turrets) and can also penetrate most lightly armored or unarmored vehicles.

Specialized warheads are available for illumination, smoke, tear gas, and white phosphorus. Russia, China and many former Warsaw Pact nations have also developed a fuel-air explosive warhead. Another recent development is a tandem HEAT warhead capable of penetrating reactive armor.[1]

Accuracy limits the standard RPG-7 to a practical range of 50 m, although it can reach 150 or even 300 m in skilled hands. It has an indirect fire (bombardment) range to 920 m, limited by the 4.5 second self-destruct timer.

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Tactics

RPGs are a low-cost, low-tech, direct fire man-portable weapon, used primarily to engage thinly-armored and unarmored vehicles and personnel. It also can be used as an anti-aircraft weapon, usually against hovering helicopters. RPGs were used extensively against the Soviet intervention forces in Afghanistan by the Mujahedin and against South Africans in Angola by the UNITA rebels.

Because of the inherent inaccuracy of the RPG, the operator must fire relatively close to the intended target, increasing the chances of being spotted and suppressed. Most modern armies use the ATGM as their primary infantry anti-tank weapon, but the RPG can still be used effectively under certain tactical conditions, especially urban warfare, where they are favored by low-tech armies and terrorist organizations. They are most effective when used in restricted terrain as the availability of cover and concealment can make it difficult for the intended target to spot the RPG operator before moving into his kill zone.

The operator must move after firing the RPG as the ignition of the rocket generates a flash visible to the enemy, and usually leaves a smoke trail leading back to the firing position. In Afghanistan, Mujahideen RPG shooters who remained in position after firing were often killed by Soviet counter-fire.

In Afghanistan, Mujahideen guerrillas used RPG-7s to destroy Soviet vehicles. To assure a kill, two to four RPG shooters would be assigned to each vehicle. In areas where vehicles were confined to a single path (a mountain road, swamps, snow, urban areas), RPG teams trapped convoys by destroying the first and last vehicles in line, preventing movement of the other vehicles. This tactic was especially effective in cities. Convoys learned to avoid approaches with overhangs, and to send infantrymen forward as a screen in hazardous areas.

Multiple shooters were also effective against heavy tanks with reactive armor: The first shot would be against the driver's viewing prisms. Following shots would be in pairs, one to set off the reactive armor, the second to penetrate the tank's armor. Favored weak spots were the top and rear of the turret. Chechen guerillas also attacked Russian tanks from basements. This was effective because the tanks' guns could not depress far enough to return fire. Both artillery suppression and infantry screens prevented antitank attacks by RPG teams. Russian tank columns were eventually protected by attached mobile antiaircraft artillery used in the ground role to suppress and destroy Chechen ambushes.

South African and Soviet APCs would be targeted as soon as they stopped to let off troops. The South Africans developed a doctrine of driving the APC in widening circles, using automatic gunfire from one side to destroy the RPG teams. This prevented the APCs from becoming stationary targets as they would if they stopped to let off troops.

The RPG is somewhat useful in the anti-aircraft role. Helicopters would typically be ambushed as they landed or hovered. The Mujahedin would modify the RPGs to make them more effective against helicopters. By adding a curved pipe to the rear of the launcher tube to divert exhaust, the RPG can be fired upward at aircraft from a prone position, making the shooter less obvious prior to firing and decreasing the risk of injury from hot exhaust gasses. Again, multiple launchers were needed in order to increase the chances of a hit. Both of the Blackhawk helicopters lost by the U.S. in Mogadishu, Somalia, were downed by RPG-7s. In Afghanistan, Soviet helicopters countered by clearing landing zones (LZs) with antipersonnel saturation fire. They also began arriving with unpredictable numbers of wingmen (two or three), to upset Afghan force estimations and preparation. The Afghans countered by digging prepared firing positions with top cover. The Soviets countered this by using air-dropped fuel-air bombs to clear LZs. The Afghans were able to counter this by using U.S.-supplied Stinger surface-to-air missiles and finally prevailed.

Afghans sometimes used RPG-7s at extreme long range, exploded by their 4.5 second self-destructs, which calculates to an almost 1 km range. This performed expedient indirect antipersonnel bombardment, and sometimes was used to discourage reconnaissance by aircraft.

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During the 2003 U.S invasion of Iraq and the subsequent occupation, the RPG has become a favorite weapon of the Iraqi guerillas fighting U.S. troops. Since most readily-available RPG-7 rounds cannot penetrate M1 Abrams tank armor, it is primarily used to attack soft-skinned Humvees in supply convoys and unarmored trucks, and also as an anti-personnel weapon against infantry foot patrols.

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History

The most widely distributed and used RPG in the world is the RPG-7, developed by the Soviet Union. The Soviets developed the basic design of the RPG during WW II, imitating and combining important design features of the US Bazooka and the German Panzerfaust.

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