The Best SSBN Submarine? The Royal Navy’s Vanguard-class submarines serve as the cornerstone of the United Kingdom’s sea-based nuclear deterrent, carrying up to 16 Trident II D5 missiles with independently targetable warheads.
-These nuclear-powered giants boast nearly unlimited underwater endurance, reflecting the U.K.’s close defense ties with the U.S., which shares missile technology under the Polaris Sales Agreement.
-However, the Vanguard-class, first commissioned in the early 1990s, faces criticism for its aging fleet and high maintenance costs. With service life extended into the 2030s, the class will eventually give way to the Dreadnought-class submarines, ensuring the continuation of Britain’s nuclear deterrence capabilities.
-The Royal Navy’s Vanguard-class submarine is a nuclear-powered ballistic missile submarine developed for the United Kingdom during the late 1980s and early 1990s.
Vanguard-Class Submarines: The Backbone of Britain’s Nuclear Deterrent
It forms the backbone of the United Kingdom’s sea-borne nuclear deterrent capability and offers decision-makers in the U.K. a robust and continual below-surface deterrent capability — and is also emblematic of the United Kingdom’s particularly close defense relationship with the United States.
Vanguard-Class SSBNs Submarines, Explained
The Royal Navy’s Vanguard-class submarines can leave port with up to 16 Trident II D5 missiles, the same carried by their American counterparts.
These long-range nuclear ballistic missiles are equipped with multiple independently targetable re-entry vehicles, also known as MIRVs, which carry a nuclear payload.
Although the technology was originally an American innovation, the British Tridents are maintained by the Brits in the United Kingdom at their own facilities, affording British sovereignty over missiles that rely on American technology.
The Royal Navy calls the Vanguards the “giants of the deep” and deservedly so: they are the largest submarines ever manufactured in the United Kingdom and, according to the Royal Navy, the third-largest vessels currently in service.
Powered by a nuclear reactor made by Rolls-Royce, the Vanguards are limited only by how much food they carry on board, and can desalinate water and provide oxygen while underwater for a virtually unlimited amount of time — a crucial valuable factor to its role as the United Kingdom’s extended deployment nuclear deterrent platform.
The Vanguard-class is a small, four-hull class: Vanguard, Victorious, Vigilant, and Vengeance, enough to ensure one hull is always at sea on patrol.
Astute-class Submarine. Image: Creative Commons.
Eventually, the Royal Navy’s Vanguards will be replaced by the Dreadnought-class submarines, further extending the United Kingdom’s close strategic partnership with the United States.
Swirling Controversy
Capable though the Vanguard is, controversy has swirled domestically about the Vanguard-class initial and operating costs.
Total costs not only for the submarines but also the Trident missiles themselves, as well as Trident and Vanguard maintenance, are estimated to run into tens of billions of pounds, raising questions about the long-term financial burden associated with the project.
Another point of criticism has been the decision to push their service life into the 2030s, much past their originally estimated retirements.
In 2012, a reactor coolant leak in the HMS Vanguard renewed questions about maintaining an increasingly aged fleet.
The Special Relationship on Submarines
It is said that the United States and the United Kingdom’s relationship is special — and this is very true. Sharing a common language and cultural similarities, the security relationship between the two countries is particularly close.
One of the most illustrative examples of the close relationship between London and Washington is the Polaris Sales Agreement, signed in the early 1960s.
The agreement paved the way for the Polaris program, under which the United States shared the crown jewel of its defense capabilities with the U.K.: an underwater nuclear deterrent and arguably the most essential part of the American nuclear triad—amended in 1982 to provide the legal framework for the upgraded Trident missile system and Polaris successor.
Ohio-Class SSGN
“The Trident submarine launched ballistic missile carries Britain’s nuclear deterrent; the ultimate guarantee of our security and that of our allies,” the Royal Navy says about the Trident. “These missiles can be fired at targets up to 4,000 miles away, ejected from the sub’s ballistic missile tubes by high-pressure gas before igniting when they reach the surface of the water.”
Into the Future For Vanguard Submarines
Though the Vanguard-class submarines remain the backbone of the Royal Navy and the United Kingdom’s nuclear deterrent capability, the submarine class is by no means young.
The first of the class, the HMS Vanguard, was commissioned in 1993, making the class over thirty years old. Their service life has already been extended due to a slower-than-expected rollout of the upcoming Dreadnought-class, which is slated to enter service in the late 2020s or early 2030s.
About the Author: Caleb Larson
Caleb Larson is an American multiformat journalist based in Berlin, Germany. His work covers the intersection of conflict and society, focusing on American foreign policy and European security. He has reported from Germany, Russia, and the United States. Most recently, he covered the war in Ukraine, reporting extensively on the war’s shifting battle lines from Donbas and writing on the war’s civilian and humanitarian toll. Previously, he worked as a Defense Reporter for POLITICO Europe. You can follow his latest work on X.
