Davy Crockett (nuclear device)

Davy Crockett was a recoilless rifle on a tripod for firing the M388 atomic round

The M-28 or M-29 Davy Crockett Weapon System(s) was a tactical nuclear recoilless gun for firing the M388 nuclear projectile that was deployed by the United States during the Cold War. Named after American soldier, congressman, and folk hero Davy Crockett, it was one of the smallest nuclear weapon systems ever built.

Development

U.S. officials view a W54 nuclear warhead, as used on the Davy Crockett. The unusually small size of the warhead is apparent.

The Davy Crockett recoilless spigot gun was developed in the late 1950s for use against Soviet troops had war broken out in Europe. Small teams of the Atomic Battle Group (charged with operating the device) would be stationed every few kilometers to guard against Soviet attack, using the power of their nuclear artillery to kill or incapacitate advancing troop formations and irradiate the area so that it was uninhabitable for up to 48 hours, long enough to mobilize NATO forces.

The M-388 round used a version of the W54 warhead, a very small sub-kiloton fission device. The Mk-54 weighed about 51 lb (23 kg), with a yield equivalent to somewhere between 10 or 20 tons of TNT (very close to the minimum practical size and yield for a fission warhead). The only selectable feature with either versions of the Davy Crockett (M28 & M29) was the height of burst dial on the warhead (post-Davy Crockett versions of the nuclear warhead apparently had a selectable yield feature). The complete round weighed 76 lb (34.5 kg). It was 31 in. (78.7 cm) long with a diameter of 11 in. (28 cm) at its widest point; a subcaliber piston at the back of the shell was inserted into the launcher's barrel for firing.^[1] The "piston" was considered a spigot prior to the discharge of the propellant cartridge in the recoilless gun chamber of the Davy Crockett. 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. The nuclear yield is hinted at in FM 9-11: Operation and Employment of the Davy Crockett Battlefield Missile, XM-28/29 (June 1963).

The M-388 could be launched from either of two launchers known as the Davy Crockett Weapon System(s): the 4-inch (120 mm) M28, with a range of about 1.25 mi (2 km), or the 6.1-in (155 mm) M29, with a range of 2.5 mi (4 km). Both weapons used the same projectile, and could be mounted on a tripod launcher transported by an armored personnel carrier, or carried by a Jeep (M-38 & later M-151); the Jeep was equipped with a launcher, whereas the Davy Crockett carried by an armored personnel carrier was set on a tripod away from the carrier. The Davy Crocketts were operated by a three-man crew.^[2]

A Davy Crockett casing preserved in the United States Army Ordnance Museum

Both recoilless guns proved to have poor accuracy in testing, so the shell's greatest effect would have been its extreme radiation hazard. The M-388 would produce an almost instantly lethal radiation dosage (in excess of 10,000 rem) within 500 feet (150 m), and a probably fatal dose (around 600 rem) within a quarter mile (400 m).^[3]

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 1.7 miles (2.72 km) in the Little Feller I test shot on July 17. This was the last atmospheric test detonation at the Nevada Test Site.

Production of the Davy Crockett began in 1956, with a total of 2,100 being made. The weapon was tested between 1962 and 1968 at the Pohakuloa Training Area on Hawaiʻi island, with 714 M101 spotter rounds (not live warheads) that contained depleted uranium.^[4][5] The weapon was deployed with U.S. Army forces from 1961 to 1971. It was inactivated from US Army Europe (in West Germany) in 1967.

Versions of the W54 warhead were also used in the Special Atomic Demolition Munition project and the AIM-26A Falcon.

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 1/2 ton truck per section, (3 per platoon) were fully air droppable. The units were deactivated in mid-1968.

Location

Below is a list of museums which have a Davy Crockett casing in their collection:

• Air Force Space & Missile Museum, Cape Canaveral Air Force Station, Florida
• National Atomic Museum, Albuquerque, New Mexico
• National Infantry Museum, Fort Benning, Georgia
• United States Army Ordnance Museum, Aberdeen Proving Ground, Maryland
• Watervliet Arsenal Museum, Watervliet, New York
• West Point Museum, West Point, New York
• Atomic Testing Museum, Las Vegas, Nevada
• Don F. Pratt Museum, Fort Campbell, Clarksville, Tennessee

See also

• Nuclear weapon
• Nuclear artillery
• Nuclear weapon design
• Nuclear strategy

References

1. ^ Characteristics of all US nuclear weapons designs, accessed October 20, 2006
2. ^ Guntruck.com Davy Crockett page, accessed October 20, 2006
3. ^ Nuclear Weapons FAQ Section 5.6, Mechanisms of Damage and Injury, accessed October 20, 2006
4. ^ Erin Miller (September 1, 2010). "Military says DU at PTA likely harmless: Army reports 'no likely adverse impacts' from spotting rounds". West Hawaii Today. http://www.westhawaiitoday.com/articles/2010/09/01/local/local01.txt. Retrieved September 2, 2010. 
5. ^ Cabrera ServicesRadiological Engineering and Remediation (June 2010). "Pohakuloa Training Area Firing Range Baseline Human Health Risk Assessment for Residual Depleted Uranium". US Army Hawaii Garrison. http://www.garrison.hawaii.army.mil/du/PTA%20BHHRA%20Report%20Rev%202.pdf. Retrieved September 2, 2010. ^{[dead link]}

External links

• Facts about the "Davy Crockett" missile
• Loaded and unloaded M29 Davy Crockett
• Characteristics of all US nuclear weapons designs
• DCs in 3rd Armored Division
• DCs on the highway
• President Kennedy questions Davy Crockett crewmen
• DC Souvenirs
• See John Marshall's Davy Crockett write up in the 3rd Bn, 36th Infantry section
• Davy Crocketts in Southern Avenue of Fulda Gap
• Davy Crocketts during Oct 62 Cuban Crisis (Southern Avenue of Fulda Gap)-- see especially bottom of jchorazy's Page 12
• Video showing testing of device on youtube.com
• Operation Ivy Flats — testing of the Davy Crockett, 1962 (17:46)
• Wee Gwen - a UK weapon similar to Davy Crockett