UK Trident force

Nuclear force componentActivePending verification

Also known as: Continuous at-sea deterrent, CASD

Nuclear ForcesGBR

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Fact cardConfidence · Source

System

TypeNuclear force component

Alternative designationsContinuous at-sea deterrent, CASD

ProliferationOrigin country only

PlatformsHMS Vanguard, Victorious, Vengeance, Vigilant; 16 tubes eachMed^[1]

BasesHMNB Clyde (Faslane); RNAD CoulportMed^[1]

Program statusDreadnought class: 4 boats with 12 tubes, early 2030sMed^[1]

Warhead inventory

Warheads deployed120 warheadsOperationally available; about 40 on the boat at seaMed^[1]

Delivery

Launchers48UK holds title to 58 Trident missiles in a pool shared with the U.S. NavyMed^[1]

Warhead typesHolbrook (Mk4A)Med^[1]

Summary

The UK's sole nuclear system: four Vanguard-class SSBNs with Trident II D5 missiles under continuous at-sea deterrence.

Draft entry. Values come from the cited public sources and are awaiting editor verification.

Operators

Sources

United Kingdom nuclear weapons, 2024, Federation of American Scientists Nuclear Notebook, Bulletin of the Atomic Scientists
Published/updated 2024-11-12 · Tier 2 · checked 2026-11-08

Change log

2026-11-08 Entry created from United Kingdom nuclear weapons, 2024 (FAS Nuclear Notebook)