The M-28 or M-29 Davy Crockett Weapon System was a tactical nuclear

recoilless A recoilless rifle, recoilless launcher or recoilless gun, sometimes abbreviated "RR" or "RCL" (for ReCoilLess) is a type of lightweight artillery system or man-portable launcher that is designed to eject some form of countermass such as propel ...

smoothbore gun for firing the M388 nuclear projectile, armed with the W54 nuclear warhead, that was deployed by the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

during the Cold War. It was the first project assigned to the United States Army Weapon Command in Rock Island, Illinois. It remains one of the smallest

nuclear weapon A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission and fusion reactions ( thermonuclear bomb), producing a nuclear explosion. Both bom ...

systems ever built, with a yield of . It is named after American folk hero, soldier, and

congress A congress is a formal meeting of the representatives of different countries, constituent states, organizations, trade unions, political parties, or other groups. The term originated in Late Middle English to denote an encounter (meeting of ...

man Davy Crockett.

History

By the year 1950, there had been rapid developments made in the use of nuclear weapons after the detonation of "

Little Boy "Little Boy" was the type of atomic bomb dropped on the Japanese city of Hiroshima on 6 August 1945 during World War II, making it the first nuclear weapon used in warfare. The bomb was dropped by the Boeing B-29 Superfortress ''Enola Gay'' p ...

" and "

Fat Man "Fat Man" (also known as Mark III) is the codename for the type of nuclear bomb the United States detonated over the Japanese city of Nagasaki on 9 August 1945. It was the second of the only two nuclear weapons ever used in warfare, the fir ...

" in 1945. These developments paved the way for nuclear warheads to be created at a smaller size. By the 1950s, advances in nuclear weapons technology, spurred on by the first detonation of the Soviet nuclear bomb in 1949, led to great reductions in the size of nuclear weapons. By 1957, the Atomic Energy Commission (AEC) declared that it had created a small fission warhead that could be deployed for frontline use by infantrymen. AEC made Major General John H. Hinrichs the leader in turning the warhead into a weapon system under the Battle Group Atomic Delivery System (BGADS) program, which began at

Picatinny Arsenal The Picatinny Arsenal ( or ) is an American military research and manufacturing facility located on of land in Jefferson and Rockaway Township in Morris County, New Jersey, United States, encompassing Picatinny Lake and Lake Denmark. The Ar ...

in New Jersey in January 1958. In August 1958, the Army began to officially refer to the BGADS as the Davy Crockett, after the American folk hero, who died at the

Battle of the Alamo The Battle of the Alamo (February 23 – March 6, 1836) was a pivotal event in the Texas Revolution. Following a 13-day siege, Mexican troops under President General Antonio López de Santa Anna reclaimed the Alamo Mission near San Anto ...

in 1836. After 4 years of testing at Forts Greeley and Wainwright in Alaska, and the Yuma Test Station in Arizona, the M28/M29 Davy Crockett entered service in May 1961. Davy Crockett sections were assigned to

United States Army Europe United States Army Europe and Africa (USAREUR-AF) is an Army Service Component Command (ASCC) /Theater Army responsible for directing United States Army operations throughout the U.S. European Command (EUCOM) and U.S. Africa Command (AFRICO ...

which included Seventh United States Army, and to Pacific Theater

Eighth United States Army The Eighth Army is a U.S. field army which is the commanding formation of all United States Army forces in South Korea. It commands U.S. and South Korean units and is headquartered at the Camp Humphreys,Inner German border in the Fulda Gap the Davy Crocketts accompanied their battalions. All Seventh Army's V Corps (including 3rd Armored Division) combat maneuver battalions had preassigned positions in the Fulda Gap. These were known as GDP (General Defense Plan) positions. The Davy Crockett sections were included in these defensive deployment plans. In addition to the Davy Crocketts (e.g., assigned to the 3rd Armored Division), Seventh Army's V Corps had nuclear artillery rounds and

atomic demolition munitions Atomic demolition munitions (ADMs), colloquially known as nuclear land mines, are small nuclear explosive devices. ADMs were developed for both military and civilian purposes. As weapons, they were designed to be exploded in the forward battle ...

, and these were also for potential use in the Fulda Gap. On the Korean peninsula, Eighth Army units assigned the Davy Crockett weapons primarily planned to use the passes that funneled armor as killing grounds, creating temporarily deadly radioactive zones roadblocked by destroyed tanks and other vehicles. Production of the Davy Crockett began at

following the 15 August 1958 approval of the design. There was approval for funding of 6,247 to be manufactured, but a total of 2,100 were actually made. The weapon was tested between 1962 and 1968 at the

Pohakuloa Training Area Pōhakuloa Training Area (PTA) is a US military training base located on the high plateau between Mauna Loa, Mauna Kea and the Hualalai, Hualālai volcanic mountains of the Hawaii (island), island of Hawaii. It includes a small military airstrip k ...

on Hawaiʻi island, with 714 M101 spotter rounds (not live warheads) that contained depleted uranium. The weapon was deployed with

US Army The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, cla ...

forces from 1961 to 1971. The 55th and 56th Infantry Platoons, attached to the Division Artillery of the US 82nd Airborne Division, were the last units equipped with the M-29 Davy Crockett weapons system. These two units were parachute deployed and, with a ton truck per section (three per platoon), were fully air droppable. The units were deactivated in mid-1968. The Davy Crockett's nuclear warhead, the M388, was removed from US Army Europe (in West Germany) in August 1967. The last nuclear-equipped warhead was retired in 1971. Brigadier General Alvin Cowan, Assistant Division Commander of 3rd Armored Division, while stating the weapon was a "significant advance" in technical terms and that the laboratory responsible deserved "a great deal of credit", further stated that the Army retired the weapon due to the personnel costs associated with it as well as apparent "great fear that some sergeant would start a nuclear war". The Davy Crockett was never used in actual combat. Since their retirement, Davy Crockett systems have been preserved in many museums throughout the United States. In 2005 the Army announced that it uncovered 600 pounds of depleted uranium from the training sites used for the Davy Crockett's inert rounds to be practice fired. They said that 12,405 acres of land could likely be tainted by these training days.

M388 nuclear round

Projectile, Atomic, Supercaliber 279mm XM388 for the Davy Crockett contained a W54 Mod 2 nuclear warhead. It was a very compact pure fission device weighing and when packaged in the M388 round weighed . The weapon had an official yield of and contained of high explosives. Controls on the projectile included a two-position height-of-burst switch that could be set to and airburst, a safety switch with 'safe' and 'arm' positions and a time setting dial that allowed a time delay between 1 and 50 seconds before the fuze armed. If the time delay was greater than the time-of-flight, the weapon would hit the ground before it armed and not detonate. The time dial also had a 'safe' setting, and so acted as a second safety switch. The complete round weighed . It was long with a diameter of at its widest point; a subcaliber piston at the back of the shell was inserted into the launcher's barrel for firing.. The M388 atomic projectile was mounted on the barrel-inserted spigot via bayonet slots. Once the propellant was discharged the spigot became the launching piston for the M388 atomic projectile: this was necessary because the fission round could not be subject to high acceleration and the spigot/piston, acting as a "pusher tube", facilitated this. In flight, four fins on the end deployed to stabilize trajectory and flight.

Practice rounds

The M390 practice round was outwardly similar to the nuclear round and was designed to be a ballistic match to it. It contained of Composition B high explosive that was detonated by an electrical switch on impact with the ground. The practice round had a significant destructive effect in its own right and was intended to be used in combat in an emergency situation. A further type of dummy training round, the M421, was completely inert and not intended to be fired.

Launcher

The M388 could be launched from either of two launchers known as the Davy Crockett Weapon System(s): the M28, with a range of about , or the M29, with a range of . The limited firing range was due to the combination of poor aerodynamics of the "watermelon with fins" (some soldiers referred to the warhead as the "atomic watermelon") type shape and the warhead's inability to withstand being fired like a traditional artillery round. This meant that it had to be fired out of a short range recoilless rifle. Both weapons fired the same projectile, propelled using a separate cartridge. The smaller M28 used a explosive cartridge to launch the warhead. The larger M29 used a 5 kg or an propellant charge, depending on the desired range. The launcher systems were muzzle loading weapons. As they were intended for a very low rate of fire a

breechloading A breechloader is a firearm in which the user loads the ammunition (cartridge or shell) via the rear (breech) end of its barrel, as opposed to a muzzleloader, which loads ammunition via the front ( muzzle). Modern firearms are generally bre ...

mechanism was unnecessary. Davy Crockett launchers were either mounted on a tripod launcher transported by an M113 armored personnel carrier, or they were carried by a Jeep (the M38, and later the

M-151

M-151, was formerly the designation of two different state trunkline highway ...

). The Jeep was equipped with an attached launcher for the M28 or the M29, as required, whereas the Davy Crockett carried by an armored personnel carrier was set up in the field on a tripod away from the carrier. The M113 was equipped to carry up to ten nuclear rounds. Weapons assigned to infantry units were carried in M113s, those allocated to airborne units were carried on Jeeps. The M28 launcher was also equipped with a 20mm

spotting rifle A spotting rifle or ranging gun is a small-calibre rifle used as a sighting device for artillery. The ballistics of the spotting rifle are matched to those of the artillery piece, so that if a shot from the spotting rifle lands on the target, it m ...

– a single-shot weapon that fired depleted uranium rounds using a

high–low system The high–low system (or high–low pressure system, high–low propulsion system, high–low projection system) is a design of cannon and anti-tank warfare launcher using a smaller high-pressure chamber to store propellant. It allows a much larger ...

. These rounds flew a similar trajectory to the nuclear projectiles and produced white smoke when they landed, helping determine range. The Davy Crockett was fired remotely. A mechanically-operated detonator at the end of of

detonating cord Detonating cord (also called detonation cord, detacord, detcord, primer cord, or sun cord) is a thin, flexible plastic tube usually filled with pentaerythritol tetranitrate (PETN, pentrite). With the PETN exploding at a rate of approximately ...

led to the propellant charge. The M388 nuclear projectile was attached to a titanium piston by means of a

bayonet mount A bayonet mount (mainly as a method of mechanical attachment, such as fitting a lens to a camera using a matching lens mount) or bayonet connector (for electrical use) is a fastening mechanism consisting of a cylindrical male side with one ...

. When fired, the piston was blown out of the tube by the detonating propellant. The piston was hollow and filled with high-pressure gas from the explosion, this pressure broke

shear pin {{unreferenced, date=September 2018 A shear pin is a mechanical detail designed to allow a specific outcome to occur once a predetermined force is applied. It can either function as a safeguard designed to break to protect other parts, or as a con ...

s that connected the piston to the nuclear projectile, detaching it after a few meters of flight. The piston would hit the ground several hundred meters in front of the weapon while the projectile continued to the target. The Davy Crocketts were operated by a five-man crew, the squad consisting of a Commander, Gunner, Assistant Gunner, Loader and Computer. The commander of the M388 could issue use and have the weapon fired in a matter of minutes. The weapon was made from lightweight metals – the tripod was aluminum, the barrel was titanium – and it was possible to break the smaller M28 weapon into three loads that could be carried by the crew, with the other two crew carrying two radios and accessories. The weight of the M28 launcher was while the bigger M29 weighed . Operating the M28 or M29 versions of the weapon with a three-man crew was also possible. In the 3rd Armored Division in Germany in the 1960s many Davy Crockett Sections (all of which were in the Heavy Mortar Platoons, in Headquarters Companies of Infantry or Armor Maneuver Battalions) received what became a mix of M28 and M29 launchers (e.g., one of each per D/C section). Eventually, the M28s were replaced by M29s, so that both the armored personnel carriers and the Jeeps carried the M29.

Effects

Both recoilless guns proved to have good accuracy in testing, most training shots landing within of the point of aim, and CEP under , with a 100% instant casualty radius in excess of . The shell's greatest effect would have been its extreme prompt neutron radiation which would have killed most of the enemy troops inside that circle within minutes. Its blast would do very little if any damage to the enemy's tracked vehicles. Troops further away would have died within hours, days and less than two weeks depending on their range from the point of burst and the thickness of their protection. The weapon's blast was not a danger to the crew as long as they followed normal procedures. The Army created a standard for the crew to follow when firing the M388; they advised that the soldiers shelter their bodies behind a sloped hill and lie in prone position on the ground with their necks and heads covered. The warhead was tested on July 7, 1962, in the Little Feller II weapons effects test shot, and again in an actual firing of the Davy Crockett from a distance of in the Little Feller I test shot on July 17, 1962. This was the last atmospheric test detonation at the

Nevada Test Site The Nevada National Security Site (N2S2 or NNSS), known as the Nevada Test Site (NTS) until 2010, is a United States Department of Energy (DOE) reservation located in southeastern Nye County, Nevada, about 65 miles (105 km) northwest of the ...

. Information and recorded data from test-firing inert rounds showed the recoilless rifles to be "shockingly inaccurate" and led to the realization that the weapon was "too inaccurate to deliver even low-yield nuclear fires".

Spending

Development of this weapon proved to be costly in all aspects of design, modifications, and labor. Over a 5 year period from 1958 to 1963, total expenses soared to nearly $20 million (equivalent to $ million in ). The initial allotted development costs varied from year to year, starting with $1.1 million in 1958, $9.15 million in 1959, $5 million in 1960, $2.4 million in 1961, $1.5 million in 1962, and $250,000 in 1963.

Proposed German military use

One of the most fervent supporters of the Davy Crockett was West Germany's defense minister Franz Josef Strauss, in the late 1950s and early 1960s. Strauss promoted the idea of equipping German brigades with the nuclear weapon, to be supplied by the US, arguing that this would allow German troops to become a much more effective factor in NATO's defense of Germany against a potential Soviet invasion. He argued that a single Davy Crockett could replace 40–50 salvos of a whole divisional artillery park – allowing the funds and troops normally needed for this artillery to be invested into further troops, or not having to be spent at all. US NATO commanders strongly opposed Strauss's ideas, as they would have made the use of tactical nuclear weapons almost mandatory in case of war, further reducing the ability of NATO to defend itself without resorting to atomic weapons.

Concerns and potential problems

Radiation exposure

The Davy Crockett Weapon System's use of depleted uranium in the spotting round led to concerns about troop exposure to the material. However, studies indicated that there was no risk of exposure to the material during use of the weapon. As a nuclear munition, however, an exceptionally strong safety program was required. This included providing render-safe procedure documentation to explosive ordnance personnel before delivery of the first warheads.

Accuracy

Program documentation for the weapon indicates that the weapon had a circular error probable (CEP) of less than . Brigadier General Alvin Cowan, Assistant Division Commander of 3rd Armored Division, while discussing the weapon's retirement commended the technical design of the weapon.

Other uses of the W54 warhead

The W54 warhead used by the Davy Crockett was initially developed for both the Davy Crockett and the

AIM-4 Falcon The Hughes AIM-4 Falcon was the first operational guided air-to-air missile of the United States Air Force. Development began in 1946; the weapon was first tested in 1949. The missile entered service with the USAF in 1956. Produced in both heat ...

air-to-air missile under the designation of XW-51. However, the development of the warhead was reassigned to

Los Alamos Scientific Laboratory Los Alamos National Laboratory (often shortened as Los Alamos and LANL) is one of the sixteen research and development laboratories of the United States Department of Energy (DOE), located a short distance northwest of Santa Fe, New Mexico, in ...

in January 1959 and redesignated the XW-54. This produced the Mark 54 mod 0 and Mark 54 Mod 2 warheads for Falcon and Davy Crockett use respectively, which were only distinguishable by the environmental sensing device employed. Later, the Special Atomic Demolition Munition (SADM – sometimes designated the B54) was developed and saw service between 1964 and 1989. SADM was so different from the W54 warhead that consideration was given to renaming the weapon with its own unique mark number. Mod numbers between the Mark 54/W54 and B54/SADM are not shared. A later development of the W54 was the W72 warhead for the

AGM-62 Walleye The AGM-62 Walleye is a television-guided glide bomb which was produced by Martin Marietta and used by the United States Armed Forces from the 1960s-1990s. Most had a 250 lb (113 kg) high-explosive warhead; some had a nuclear warhea ...

television-guided glide bomb system.

Museum examples

The following museums have a Davy Crockett casing in their collection: *

National Museum of the United States Army The National Museum of the United States Army is the official museum for the history of the United States Army and is just outside Washington, D.C. It opened on November 11, 2020. The objectives of the museum are to honor America's soldiers, pre ...

Fort Belvoir Fort Belvoir is a United States Army installation and a census-designated place (CDP) in Fairfax County, Virginia, United States. It was developed on the site of the former Belvoir plantation, seat of the prominent Fairfax family for whom Fai ...

, Fairfax County, Virginia * Air Force Space and Missile Museum,

Cape Canaveral Space Force Station Cape Canaveral Space Force Station (CCSFS) is an installation of the United States Space Force's Space Launch Delta 45, located on Cape Canaveral in Brevard County, Florida. Headquartered at the nearby Patrick Space Force Base, the statio ...

, Florida *

National Museum of Nuclear Science & History The National Museum of Nuclear Science & History (formerly named National Atomic Museum) is a national repository of nuclear science information chartered by the 102nd United States Congress under Public Law 102-190, and located in unincorporated ...

, adjacent to

Kirtland AFB Kirtland Air Force Base is a United States Air Force base located in the southeast quadrant of the Albuquerque, New Mexico urban area, adjacent to the Albuquerque International Sunport. The base was named for the early Army aviator Col. Ro ...

, Albuquerque, New Mexico * National Infantry Museum, Fort Benning, Georgia * United States Army Ordnance Training and Heritage Center, Fort Lee, Prince George County, Virginia (closed to public) * Watervliet Arsenal Museum, Watervliet, New York *

West Point Museum The United States Military Academy (USMA), also known metonymically as West Point or simply as Army, is a United States service academy in West Point, New York. It was originally established as a fort, since it sits on strategic high groun ...

United States Military Academy The United States Military Academy (USMA), also known metonymically as West Point or simply as Army, is a United States service academy in West Point, New York. It was originally established as a fort, since it sits on strategic high groun ...

, West Point, New York *

National Atomic Testing Museum The National Atomic Testing Museum in Las Vegas, Nevada, documents the history of nuclear testing at the Nevada Test Site (NTS) in the Mojave Desert about 65 miles (105 km) northwest of Las Vegas. The museum operates as an affiliate of the Smithso ...

, Las Vegas, Nevada *

Don F. Pratt Memorial Museum Don F. Pratt Memorial Museum is an official U.S. Army Museum located in Building 5702 on Tennessee Avenue at Fort Campbell, Kentucky. Military artifacts and memorabilia are available to touch and view at the museum which features interior and exte ...

Fort Campbell Fort Campbell is a United States Army installation located astride the Kentucky–Tennessee border between Hopkinsville, Kentucky and Clarksville, Tennessee (post address is located in Kentucky). Fort Campbell is home to the 101st Airborne Divi ...

, Clarksville, Tennessee

References

Citations

Bibliography

External links

{{Commons category, M388 Davy Crockett *M-28/2
Facts about the "Davy Crockett" launcher and warheadLoaded and unloaded M29 Davy Crockettand Height of Burst Switch D/C Launching Piston
* ttps://web.archive.org/web/20110719064514/http://www.1-33rdar.org/fulagap.htm Davy Crocketts in Southern Avenue of Fulda Gapbr> Davy Crocketts during Oct 62 Cuban Crisis (Southern Avenue of Fulda Gap)-- see especially bottom of jchorazy's Page 12Video showing testing of device on youtube.comOperation Ivy Flats
— testing of the Davy Crockett, 1962 (17:46)

Recoilless rifles of the United States Nuclear artillery Cold War weapons of the United States Nuclear weapons of the United States