W68
title: "W68" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["nuclear-warheads-of-the-united-states", "military-equipment-introduced-in-the-1970s"] topic_path: "geography/united-states" source: "https://en.wikipedia.org/wiki/W68" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::data[format=table title="Infobox weapon"]
| Field | Value |
|---|---|
| name | W68 |
| image | W68_Mk3_reentry_body.jpg |
| image_size | 300 |
| caption | A W68 warhead in a Mk3 reentry Body. See image below for scale. |
| type | Nuclear weapon |
| is_explosive | yes |
| service | 1971-1991 |
| used_by | United States. |
| designer | Lawrence Livermore National Laboratory |
| production_date | June 1970 - June 1975 |
| number | 5250 |
| weight | 150 lb |
| detonation | Contact, airburst |
| yield | 40 ktTNT |
| :: |
| name = W68 | image = W68_Mk3_reentry_body.jpg | image_size = 300 | caption = A W68 warhead in a Mk3 reentry Body. See image below for scale. | origin = | type = Nuclear weapon | is_explosive = yes | service = 1971-1991 | used_by = United States. | wars = |designer = Lawrence Livermore National Laboratory |design_date = |manufacturer = |unit_cost = |production_date = June 1970 - June 1975 |number = 5250 |variants = |spec_label = |weight = 150 lb |length = |part_length = |width = |height = |diameter = |filling = |filling_weight = |detonation = Contact, airburst |yield = 40 ktTNT ::figure[src="https://upload.wikimedia.org/wikipedia/commons/e/eb/US_missile_and_rocket_hallway_(navy).jpg" caption="W68 with table and models for scale."] ::
The W68 warhead was the warhead used on the UGM-73 Poseidon SLBM missile. It was developed in the late 1960s at Lawrence Livermore National Laboratory.
Specifications
The W68 weighed 150 lb and had an official design yield of 40 ktTNT.
The design was revolutionary and impacted many following systems with its achievements in warhead miniaturization.
The W68 had four fuzing options: low altitude radar with contact backup, high altitude radar with timer backup, high altitude timer with impact backup and impact fuzing.
Production and deployment
A total of 5,250 W68 warheads were produced, the single largest production run of any American nuclear weapon model. It was manufactured starting in June 1970 and ending in June 1975. Each Poseidon missile could carry up to 14 warheads; at the peak deployment, there were 31 US Poseidon submarines with 16 missiles each, for a total of 496 deployed missiles, at a density of about 10 warheads per missile.
Safety issues and later service
Aging of the LX-09 polymer-bonded explosive used in the W68 led to decomposition of the explosive, separating the binder and plasticizer, which then caused deterioration of the detonators. This required the whole production run to be retired or remanufactured with LX-10 and LX-10-1 as new explosives from November 1978 through 1983; about 2,000 units were retired starting in 1977 rather than rebuilt.
The remaining 3,200 warheads remained in service longer, with the last units retired in 1991.
References
References
- (October 1975). "The US ICBM Force: Current Issues and Future Options". RAND Institute.
- (1969-05-05). "Minutes of National Security Council Meeting".
- (February 17, 2005). "Accomplishments in the 1970s: LLNL's 50th Anniversary".
- (September 1990). "Sandia Weapon Review: Nuclear Weapon Characteristics Handbook". Sandia National Labs.
- "W68 warhead". globalsecurity.org.
- "Warhead Accidents". Banthebomb.org.
- Carey Sublette. (1999-02-20). "4.1.6.2.2.5 Explosives". 4. Engineering and Design of Nuclear Weapons: 4.1 Elements of Fission Weapon Design.
- (June 2014). "LLNL explosives accident training web page". Lawrence Livermore National Laboratory (LLNL).
- (1981-10-03). "Relatives of 3 Killed in Blast At Nuclear Plant Lose Suit". New York Times.
- Carey Sublette. (2006-10-04). "Complete List of All U.S. Nuclear Weapons: W-68".
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