W33 (nuclear weapon)

The W33 was an American nuclear artillery shell, fired from an 8" (203 mm) howitzer.

There were a total of 2,000 W33 shells produced. It was first produced in 1957 and saw service until 1992.

Description

The W33 is 8 inches in diameter and 37 inches long; it weighs 243 pounds.

As with most other early nuclear artillery shells such as the 11" W9 shell, it was a compact gun type nuclear weapon, firing a small projectile down an internal barrel into a larger HEU uranium target assembly, forming a critical mass as the two came together.

Four variants were produced:
* Y1 - 0.5 kiloton yield
* Y2 - 40 kiloton yield
* Y3 - 10 kiloton yield
* Y4 - 5 kiloton yield

The Y2 variant may have been boosted with a deuterium-tritium gas.

Internal mechanism

All US gun-type nuclear weapons other than the W33 are strongly believed to be single-gun type weapons, in which a single barrel and single nuclear HEU projectile is fired into a static larger HEU target and tamper/reflector assembly.

Information regarding the W33 has suggested that it was either a double gun and/or that it may have used an annular barrel assembly. The device's internal mechanism was apparently code-named "Fleegle". A double gun mechanism reduces the required velocity of each projectile by half, which reduces the gun system weight by a factor of 8. An annular bore may allow a larger projectile which remains subcritical by itself (a hollow projectile has lower effective density, and critical mass scales with the square of density).
Titanium was used in order to save weight in some components. Judging by the remaining photographic evidence, it is likely that the exterior casing of the artillery shell itself was made of titanium. This is logical, given that the copper-alloy driving band around the base of the shell is the only part of the shell which engages with the rifling on the artillery piece's barrel. [ [http://nuclearweaponarchive.org/Nwfaq/Nfaq4-1.html#Nfaq4.1.6.1 Nuclear Weapons FAQ sect 4.1.6.1 Gun Assembly v 2.04] , Carey Sublette, 1999. Accessed June 4, 2006.]

The W33 mechanism has been reported to have comprised two critical nuclear parts which were required to assemble a complete W33 warhead. The initial dissassembly of stockpiled W33 warheads in 1992 proceeded first by dissassembling all of one of the components, and then dissassembling the other one in following years. [Testimony of Dr. E. Beckner to House Appropriations Committee regarding nuclear weapons program status for FY 1994 budget, April 28, 1993, at [http://www.globalsecurity.org/cgi-bin/texis.cgi/webinator/search/?query=israel+nuclear&pr=default&order=r&cmd=context&id=42b61c94155] Accessed June 5, 2006]

Tests

The W33 is the third known model of gun type nuclear bombs to have been detonated as a test. The W33 was tested twice, first the in Operation Plumbbob Laplace, on Sept 8, 1957 (Yield of 1 kt), [ [http://www.johnstonsarchive.net/nuclear/atest56.html Chronological Listing of Above Ground Nuclear Detonations 1956-1957] compiled by William Johnston, 2005; accessed June 2, 2006.] and the TX-33Y2 in Operation Nougat Aardvark on May 12, 1962, with a yield of 40 kilotons. [ [http://www.johnstonsarchive.net/nuclear/tests/USA-ntests1.html Database of nuclear tests, United States: part 1, 1945-1963] compiled by William Johnston, 2005; accessed June 2, 2006.] [ [http://nuclearweaponarchive.org/Usa/Tests/Nougat.html Operation Nougat] at the [http://nuclearweaponarchive.org nuclearweaponarchive.org] website, Carey Sublette; accessed June 2, 2006]

Neither test involved firing a W33 from an actual howitzer.Laplace Plumbob was test fired with the device hanging from a balloon at an altitude of 750 feet.Nougat Aardvark was test fired underground, at a depth of 1,424 feet.

Prior gun-type detonations were the Little Boy Mark-1 nuclear weapon used on Hiroshima in World War II, and a test firing of the W9 11 inch nuclear artillery shell in test shot Upshot-Knothole Grable on May 25, 1953.

ee also

* Nuclear artillery
* W9 (nuclear warhead)
* List of nuclear weapons

External links

* [http://nuclearweaponarchive.org/Usa/Weapons/Allbombs.html Allbombs.html] list of all US nuclear weapons models at [http://nuclearweaponarchive.org nuclearweaponarchive.org]
* [http://www.globalsecurity.org/wmd/systems/nuke-list.htm Historical nuclear weapons list] at [http://www.globalsecurity.org globalsecurity.org]

References