Bazooka


Bazooka is the common name for a man-portable recoilless anti-tank rocket launcher weapon, widely deployed by the United States Army. Also referred to as the "Stovepipe", the innovative bazooka was among the first generation of rocket-propelled anti-tank weapons used in infantry combat. Featuring a solid-propellant rocket for propulsion, it allowed for high-explosive anti-tank warheads to be delivered against armored vehicles, machine gun nests, and fortified bunkers at ranges beyond that of a standard thrown grenade or mine. The universally-applied nickname arose from the M1 variant's vague resemblance to the musical instrument called a "bazooka" invented and popularized by 1930s U.S. comedian Bob Burns.
During World War II, German armed forces captured several bazookas in early North Africa and Eastern Front encounters and soon reverse engineered their own version, increasing the warhead diameter to 8.8 cm and widely issuing it as the Raketenpanzerbüchse "Panzerschreck". Near the end of the war, the Japanese developed a similar weapon, the Type 4 70 mm AT Rocket Launcher, which featured a rocket propelled grenade of a different design.
The term "bazooka" still sees informal use as a generic term referring to any ground-to-ground shoulder-fired missile weapon.

Design and development

The development of the bazooka involved the development of two specific lines of technology: the rocket-powered weapon, and the shaped-charge warhead. It was also designed for easy maneuverability and access.

World War I

The rocket-powered weapon was the brainchild of Dr. Robert H. Goddard as a side project of his work on rocket propulsion. Goddard, during his tenure at Clark University, and while working at Worcester Polytechnic Institute's magnetic lab and Mount Wilson Observatory, designed a tube-fired rocket for military use during World War I. He and his co-worker, Dr. Clarence N. Hickman, successfully demonstrated his rocket to the US Army Signal Corps at Aberdeen Proving Ground, Maryland, on November 6, 1918, but as the Compiègne Armistice was signed only five days later, further development was discontinued. The delay in the development of the bazooka was as a result of Goddard's serious bout with tuberculosis. Goddard continued to be a part-time consultant to the US government at Indian Head, Maryland, until 1923, but soon turned his focus to other projects involving rocket propulsion. Hickman later became head of the National Defense Research Committee in the 1940s where he guided rocket development for the war effort, including completing the development of the bazooka.

Shaped charge development

technology was developed in the US into a shaped charge hand grenade for use by infantry, effective at defeating up to 60 mm of vehicle armor. The grenade was standardized as the M10. However, the M10 grenade weighed 3.5 lb, was difficult to throw by hand, and too heavy to be launched as a rifle grenade. The only practical way to use the weapon was for an infantryman to place it directly on the tank, an unlikely means of delivery in most combat situations. A smaller, less powerful version of the M10, the M9, was then developed, which could be fired from a rifle. This resulted in the creation of a series of rifle grenade launchers, the M1, the M2, the M7, and the M8. However, a truly capable anti-tank weapon had yet to be found, and following the lead of other countries at the time, the U.S. Army prepared to evaluate competing designs for a more effective man portable anti-tank weapon.
The combination of rocket motor and shaped charge warhead would lead to Army development of light antitank weapons.

Rocket-borne shaped charge weapons development

In 1942, U.S. Army Colonel Leslie Skinner received the M10 shaped-charge grenade which was capable of stopping German tanks. He gave Lieutenant Edward Uhl the task of creating a delivery system for the grenade. Uhl created a small rocket, but needed to protect the firer from the rocket exhaust and aim the weapon. According to Uhl,
By late 1942, the improved Rocket Launcher, M1A1 was introduced. The forward hand grip was deleted, and the design simplified. The production M1A1 was 55 inches long and weighed only 12.75 pounds.
The ammunition for the original M1 launcher was the M6, which was notoriously unreliable. The M6 was improved and designated M6A1, and the new ammunition was issued with the improved M1A1 launcher. After the M6, several alternative warheads were introduced. Many older M1 launchers were modified to M1A1 standards in July and August 1943, with batches of M6 rockets also being modified with the latest ignition systems to be able to be fired from the modified M1 launchers; these rockets were designated M6A2. The M6A3 rocket featured a blunt, rounded nose to lessen the chances of it ricocheting off of angled armor, and was meant to be fired from the M9, and later M9A1, launchers. Late in World War II, the M6A4 and M6A5 rockets with improved fuses were developed. These rockets arrived too late to see service during the war, but were used post-war.
The 2.36 inch Smoke Rocket M10 and its improved subvariants used the rocket motor and fin assembly of the M6A1, but replaced the anti-tank warhead with a white phosphorus smoke head. WP smoke not only acts as a visible screen, but its burning particles can cause severe injuries to human skin. The M10 was therefore used to mark targets, to blind enemy gunners or vehicle drivers, or to drive troops out of bunkers and dugouts. The 2.36-Inch Incendiary Rocket T31 was an M10 variant with an incendiary warhead designed to ignite fires in enemy-held structures and unarmored vehicles, or to destroy combustible supplies, ammunition, and materiel; it was not often utilized.
The original M1 and M1A1 rocket launchers were equipped with simple fixed sights and used a launch tube without reinforcements. During the war, the M1A1 received a number of running modifications. The battery specification was changed to a larger, standard battery cell size, resulting in complaints of batteries getting stuck in the wood shoulder rest. The M1 and M1A1 used a rear iron sight and a front rectangular "ladder" sight positioned at the muzzle. The vertical sides of the ladder sight were inscribed with graduations of 100, 200, 300, and 400 yards, with the user elevating the bazooka so the rear sight lined up with the selected "rung" on the front sight. On the M9, the ladder sight was replaced by the General Electric T43 aperture sight. Ranging was accomplished by looking through the rear sight's peep hole while rotating the assembly so it lined up with the blade positioned at the muzzle. In September 1944, during the production of the M9A1, the T43 sight was replaced by the Polaroid T90 optical reflector sight, which used an etched reticle for aiming. The T43 and T90 sights were interchangeable. Various types of blast deflectors were tried, and an additional strap iron shoulder brace was fitted to the M9 launcher.
The bazooka required special care when used in tropical or arctic climates or in severe dust or sand conditions. Rockets were not to be fired at temperatures below 0 °F or above 120 °F.

Field experience induced changes

In 1943, field reports of rockets sticking and prematurely detonating in M1A1 launch tubes were received by Army Ordnance at Ogden Arsenal and other production facilities. At the US Army's Aberdeen Proving Grounds, various metal collars and wire wrapping were used on the sheet metal launch tube in an effort to reinforce it. However, reports of premature detonation continued until the development of bore slug test gauges to ensure that the rocket did not catch inside the launch tube.
The original M6 and M6A1 rockets used in the M1 and M1A1 launchers had a pointed nose, which was found to cause deflection from the target at low impact angles. In late 1943, another 2.36-in rocket type was adopted, the M6A3, for use with the newly standardized M9 rocket launcher. The M6A3 was 19.4 inches long, and weighed 3.38 lb. It had a blunted, more round nose to improve target effect at low angles, and a new circular fin assembly to improve flight stability. The M6A3 was capable of penetrating of armor plate.
Battery problems in the early bazookas eventually resulted in replacement of the battery-powered ignition system with a magneto sparker system operated through the trigger. A trigger safety was incorporated into the design that isolated the magneto, preventing misfires that could occur when the trigger was released and the stored charge prematurely fired the rocket. The final major change was the division of the launch tube into two discrete sections, with bayonet-joint attachments. This was done to make the weapon more convenient to carry, particularly for use by airborne forces. The final two-piece launcher was standardized as the M9A1. In September 1944, the fragile folding aperture sight was replaced by a Polaroid optical reflector sight However, the long list of incorporated modifications increased the launcher's tube length to 61 inches, with an overall empty weight of 14.3 lb. From its original conception as a relatively light, handy, and disposable weapon, the final M9A1 launcher had become a heavy, clumsy, and relatively complex piece of equipment.
In October 1944, after receiving reports of inadequate combat effect of the M1A1 and M9 launchers and their M6A1 rockets, and after examining captured examples of the German 8.8 cm RPzB 43 and RPzB 54 Panzerschreck, the US Ordnance Corps began development on a new, more powerful anti-tank rocket launcher, the 3.5-inch M20. However, the weapon's design was not completed until after the war and saw no action against an enemy until Korea.
In 1945, the U.S. Army's Chemical Warfare Service standardized improved chemical warfare rockets intended for the new M9 and M9A1 launchers, adopting the M26 Gas Rocket, a cyanogen chloride -filled warhead for the 2.36-in rocket launcher. CK, a deadly blood agent, was capable of penetrating the protective filter barriers in some gas masks, and was seen as an effective agent against Japanese forces, whose gas masks lacked the impregnants that would provide protection against the chemical reaction of CK. While stockpiled in US inventory, the CK rocket was never deployed or issued to combat personnel.

Aviation use

Following Operation Overlord in 1944, the military version of the slow-flying Piper J-3 Cub high-wing civilian monoplane, the L-4 Grasshopper, began to be used in a light anti-armor role by a few U.S. Army artillery spotter units over France; these aircraft were field-outfitted with either two or four bazookas attached to the lift struts, against German armored fighting vehicles.
Upon arriving in France in 1944, US Army Major Charles Carpenter, an Army aviator flying liaison and artillery-spotting lightplanes like the military version of the Piper J-3 Cub, the L-4 Grasshopper, was issued a new L-4H version during the concluding stages of "Overlord", taking this "light attack" role against German armor by himself. With a 150-pound pilot and no radio aboard, the L-4H had a combined cargo and passenger weight capacity of approximately 232 pounds. This margin allowed him to eventually mount a total of six bazookas, three per side on the lift struts as other L-4s had done.
Within a few weeks, Carpenter was credited with knocking out a German armored car and four tanks. Carpenter's plane was known as "Rosie the Rocketer", and his exploits were soon featured in numerous press accounts, including Stars and Stripes, the Associated Press, Popular Science, The New York Sun, and Liberty Magazine. Carpenter once told a reporter that his idea of fighting a war was to "attack, attack and then attack again." During the critical late-September Battle of Arracourt, Carpenter managed to achieve disabling hits on several German armored cars and even two Panther tanks, along with killing or wounding a dozen or more enemy soldiers.
In the opening months of the Korean War era, in August 1950 a joint US Navy and Marine Corps test used a newly acquired Bell HTL-4 helicopter to test if a bazooka could be fired from a helicopter in flight. One of the larger 3.5 inch models of the Bazooka was chosen, and was mounted ahead and to the right of the helicopter to allow the door to remain clear. The bazooka was successfully tested, although it was discovered that it would require shielding for the engine compartment, which was exposed in the model 47 and other early helicopters. The helicopter itself belonged to HMX-1, a Marine experimental helicopter squadron.

Origin of the "bazooka" name

Shortly after the first prototype launcher and rockets had been tested by firing into the Potomac River, Skinner and Uhl took the new system to a competitive trial of various types of spigot mortar, which was held at the Aberdeen Proving Ground in May 1942. The new rocket launcher scored several hits on a moving tank while the five different mortars achieved none; this was a considerable achievement since the launcher's sights had been fabricated that morning from a wire coat hanger. The trial was being watched by various senior officers, among them the Chief of Research and Engineering in the Ordnance Department, Major General Gladeon M. Barnes. Barnes was delighted by the performance of the system and fired it himself, but commented: "It sure looks like Bob Burns' bazooka". Bob Burns was a popular radio comedian, who used a novelty musical instrument which he had devised himself and called a "bazooka".

Operational use

World War II

In September 1942, a consignment of 600 M1 bazookas was shipped to Egypt for use by the British Army in the Western Desert campaign. In a demonstration to British commanders, a bazooka penetrated the frontal armor of a captured Panzer III; however it was decided that the desert terrain lacked the concealment required for such a short range weapon and it was not deployed in that theater. Secretly introduced via the Russian front and in November 1942 during Operation Torch, early production versions of the M1 launcher and M6 rocket were hastily supplied to some of the U.S. invasion forces during the landings in North Africa. On the night before the landings, Gen. Dwight D. Eisenhower was shocked to discover from a subordinate that none of his troops had received any instruction in the use of the bazooka.
Initially supplied with the highly unreliable M6 rocket and without training, the M1 did not play a significant armed role in combat in the North African fighting, but did provide a German intelligence coup when some were captured by the Germans in early encounters with inexperienced US troops. A US general visiting the Tunisian front in 1943 after the close of combat operations could not find any soldiers who could report that the weapon had actually stopped an enemy tank. Further issue of the bazooka was suspended in May 1943.
1944.
During the Allied invasion of Sicily, small numbers of the M1A1 bazooka were used in combat by US forces. The M1A1 accounted for four medium German tanks and a heavy Tiger I, with the latter being knocked out by an improbable hit through the driver's vision slot.
When the existence of the bazooka was revealed to the American public, official press releases for the first two years stated that it "packed the wallop of a 155mm cannon"—a great exaggeration.
In late 1942, numbers of early-production American M1 bazookas were captured by German troops from Red Army forces who had been given quantities of the bazooka under Lend-Lease. There were also examples captured during the Operation Torch invasions in the North African Campaign. The Germans promptly developed their own version of the weapon called the Panzerschreck, increasing the diameter of the warhead from 60 mm to 88 mm, which as a result, gave it significantly greater armor penetration. During U.S. trials of the M1, calls for a larger-diameter warhead had also been raised by some ordnance officers but were rejected. Later in the war, after participating in an armor penetration test involving a German Panther tank using both the Raketenpanzerbüchse, or RPzB 54 Panzerschreck and the U.S. M9 bazooka, Corporal Donald E. Lewis of the U.S. Army informed his superiors that the Panzerschreck was "far superior to the American bazooka": 'I was so favorably impressed I was ready to take after the Krauts with their own weapon.'
The M1 bazooka fared much better on the rare occasions when it could be used against the much thinner armor typically fitted to the lower sides, underside, and top of enemy tanks. To hit the bottom panel of an enemy tank, the bazooka operator had to wait until the tank was surmounting a steep hill or other obstruction, while hitting the top armor usually necessitated firing the rocket from the upper story of a building or similar elevated position. Even the heavy King Tiger tank only possessed hull and turret top armor thicknesses of 44 mm thickness at best, capable of being pierced by the bazooka's shaped-charge rocket ordnance. During the 1944 Allied offensive in France, when some examples of liaison aircraft with the U.S. Army began to be experimentally field-armed, and were already flying with pairs or quartets of the American ordnance—and most notably used during the Battle of Arracourt—Major Charles "Bazooka Charlie" Carpenter mounted a battery of three M9 bazookas on the wing-to-fuselage struts on each side of his L-4 Grasshopper aircraft in order to attack enemy armor, and was credited with destroying six enemy tanks, including two Tiger I heavy tanks.
with "Schürzen" armor skirts
Despite the introduction of the M9 bazooka with its improved rocket—the M6A3—in late 1943, reports of the weapon's effectiveness against enemy armor decreased alarmingly in the latter stages of World War II, as new German tanks with thicker and better-designed armor plate and Schurzen armor skirts/spaced armor were introduced. This development forced bazooka operators to target less well-protected areas of the vehicle, such as the tracks, drive sprockets, wheels, or rear engine compartment. In a letter dated May 20, 1944, Gen. George S. Patton stated to a colleague that "the purpose of the bazooka is not to hunt tanks offensively, but to be used as a last resort in keeping tanks from overrunning infantry. To insure this, the range should be held to around 30 yards."
In the Pacific campaign, as in North Africa, the original bazookas sent to combat often had reliability issues. The battery-operated firing circuit was easily damaged during rough handling, and the rocket motors often failed because of high temperatures and exposure to moisture, salt air, or humidity. With the introduction of the M1A1 and its more reliable rocket ammunition, the bazooka was effective against some fixed Japanese infantry emplacements such as small concrete bunkers and pill boxes. Against coconut and sand emplacements, the weapon was not always effective, as these softer structures often reduced the force of the warhead's impact enough to prevent detonation of the explosive charge. Later in the Pacific war, Army and Marine units often used the M2 flamethrower to attack such emplacements. In the few instances in the Pacific where the bazooka was used against tanks and armored vehicles, the rocket's warhead easily penetrated the thin armor plate used by the Japanese and destroyed the vehicle. Overall, the M1A1, M9, and M9A1 rocket launchers were viewed as useful and effective weapons during World War II, though they had been primarily employed against enemy emplacements and fixed fortifications, not as anti-tank weapons. General Dwight Eisenhower later described it as one of the four "Tools of Victory" which won World War II for the Allies.
During the war, Bazookas were lend-leased to United Kingdom, Brazil, Canada, China, Free French forces as well as the Soviet Union. Some were supplied to French maquis and Yugoslav Partisans.

Korean War

The success of the more powerful German Panzerschreck caused the bazooka to be completely redesigned at the close of World War II. A larger, 3.5 in model was adopted, the M20 "Super Bazooka". Though bearing a superficial resemblance to the Panzerschreck, the M20 had greater effective range, penetrating capability and was nearly 20% lighter than its German counterpart. The M20 weighed 14.3 pounds and fired a hollow shaped-charge 9 lb M28A2 HEAT rocket when used in an anti-tank role. It was also operated by a two-man team and had a rate of fire of six shots per minute. As with its predecessor, the M20 could also fire rockets with either practice or WP smoke warheads. Having learned from experience of the sensitivity of the bazooka and its ammunition to moisture and harsh environments, the ammunition for the new weapon was packaged in moisture-resistant packaging, and the M20's field manual contained extensive instructions on launcher lubrication and maintenance, as well as storage of rocket ammunition. When prepared for shipment from the arsenal, the weapon was protected by antifungal coatings over all electrical contacts, in addition to a cosmoline coating in the hand-operated magneto that ignited the rocket. Upon issue, these coatings were removed with solvent to ready the M20 for actual firing.
Budget cutbacks initiated by Secretary of Defense Louis A. Johnson in the years following World War II effectively canceled the intended widespread issue of the M20, and initial US forces deploying to Korea were armed solely with the M9/M9A1 2.36-in. launcher and old stockpiled World War II inventories of M6A3 rocket ammunition. During the initial stages of the Korean War, complaints resurfaced over the ineffectiveness of the 2.36-inch M9 and M9A1 against Soviet-supplied enemy armor. In one notable incident, infantry blocking forces of the US Army's Task Force Smith were overrun by 33 North Korean T-34-85 tanks despite repeatedly firing 2.36 inch rockets into the rear engine compartments of the vehicles. Additionally, Ordnance authorities received numerous combat reports regarding the failure of the M6A3 warhead to properly detonate upon impact, eventually traced to inventories of rocket ammunition that had deteriorated from numerous years of storage in humid or salt air environments. Supplies of 3.5- in M20 launchers with M28A2 HEAT rocket ammunition were hurriedly airlifted from the United States to South Korea, where they proved very effective against the T-34 and other Soviet tanks. Large numbers of 2.36-inch bazookas that were captured during the Chinese Civil War were also employed by the Chinese forces against the American Sherman and Patton tanks, and the Chinese later reverse engineered and produced a copy of the M20 designated the Type 51. It is considered that the Communist-used bazookas destroyed more tanks than the UN bazookas did.

Vietnam War

The M20 "Super Bazooka" was used in the early stages of the war in Vietnam by the US Marines before gradually being phased out by the mid-1960s in favor of the M67 recoilless rifle and later, the M72 LAW rocket. The US Army also used it in lesser quantity. While occasions to destroy enemy armored vehicles proved exceedingly rare, it was employed against enemy fortifications and emplacements with success. The M20 remained in service with South Vietnamese and indigenous forces until the late 1960s.
The Vietnam People's Army also developed their own bazooka under the management of Tran Dai Nghia. It was successfully test-fired in 1947. The anti-French Viet Minh received Chinese Type 51 Bazookas. They were used by the Viet Cong as late as 1964.

Other conflicts

The Portuguese Armed Forces used quantities of M9A1 and M20 rocket launchers in their overseas provinces in Africa against Marxist guerrilla forces during the Portuguese Overseas War. The French Army also used the M9A1 and M20A1 launchers in various campaigns in Indochina, Korea, and Algeria. The M20A1 was replaced in the 1970s by the LRAC F1. Commonwealth armies also used the M20 and M20A1 under the name M20 Mk I and M20 Mk II. They were used until their replacement by the Carl Gustav L14A1. For instance, British Army used Super Bazookas during the Operation Vantage.
The Argentine Army fielded M20s during the Falklands War.

Variants

Rocket Launcher, M1 "Bazooka"

An optical reflector sight replaced the iron sights beginning in September 1944
The M9A1 supplanted the M9 in production beginning in June, 1944.
It had an improved coupling mechanism for launch tube; the overall length was and when folded. Unloaded weight was.

Rocket Launcher, M18 "Bazooka"

M1