The Ohio class of nuclear-powered submarines includes the United States Navy's 14 ballistic missile submarines (SSBNs) and its four cruise missile submarines (SSGNs). Each displacing 18,750 tons submerged, the Ohio-class boats are the largest submarines ever built for the U.S. Navy. They are also the third-largest submarines ever built, behind the Russian Navy's Soviet era 48,000-ton Typhoon class, the last of which was retired in 2023, and 24,000-ton Borei class. Capable of carrying 24 Trident II missiles apiece, the Ohio class are equipped with just as many missiles as, if not more than, either the Borei class (16) or the deactivated Typhoon class (20).
The UGM-27 Polaris missile was a two-stage solid-fueled nuclear-armed submarine-launched ballistic missile (SLBM). As the United States Navy's first SLBM, it served from 1961 to 1980.
The Trident missile is a submarine-launched ballistic missile (SLBM) equipped with multiple independently targetable reentry vehicles (MIRV). Originally developed by Lockheed Missiles and Space Corporation, the missile is armed with thermonuclear warheads and is launched from nuclear-powered ballistic missile submarines (SSBNs). Trident missiles are carried by twelve United States Navy Ohio-class submarines, with American warheads, as well as four Royal Navy Vanguard-class submarines, with British warheads. The missile is named after the mythological trident of Neptune.
The Vanguard class is a class of nuclear-powered ballistic missile submarines (SSBNs) in service with the Royal Navy. The class was introduced in 1994 as part of the Trident nuclear programme, and comprises four vessels: Vanguard, Victorious, Vigilant and Vengeance, built between 1986 and 1999 at Barrow-in-Furness by Vickers Shipbuilding and Engineering, now owned by BAE Systems. All four boats are based at HM Naval Base Clyde , 40 km (25 mi) west of Glasgow, Scotland.
A ballistic missile submarine is a submarine capable of deploying submarine-launched ballistic missiles (SLBMs) with nuclear warheads. These submarines became a major weapon system in the Cold War because of their nuclear deterrence capability. They can fire missiles thousands of kilometers from their targets, and acoustic quieting makes them difficult to detect, thus making them a survivable deterrent in the event of a first strike and a key element of the mutual assured destruction policy of nuclear deterrence. The deployment of ballistic missile submarines is dominated by the United States and Russia. Smaller numbers are in service with France, the United Kingdom, China and India; North Korea is also suspected to have an experimental submarine that is diesel-electric powered.
HMS Triumph is a Trafalgar-class nuclear submarine of the Royal Navy and was the seventh and final boat of her class. She is the nineteenth nuclear-powered hunter-killer submarine built for the Royal Navy. Triumph is the tenth vessel, and the second submarine, to bear the name. The first HMS Triumph was a 68-gun galleon built in 1561. As of 2022, she is the last boat of her class remaining in service.
HMS Northumberland is a Type 23 frigate of the Royal Navy. She is named after the Duke of Northumberland. She is the eighth RN ship to bear the name since the first 70-gun ship of the line in 1679, and the ninth in the class of Type 23 frigates. She is based at Devonport and is part of the Devonport Flotilla.
The UGM-133A Trident II, or Trident D5 is a submarine-launched ballistic missile (SLBM), built by Lockheed Martin Space in Sunnyvale, California, and deployed with the United States and Royal Navy. It was first deployed in March 1990, and remains in service. The Trident II Strategic Weapons System is an improved SLBM with greater accuracy, payload, and range than the earlier Trident C-4. It is a key element of the U.S. strategic nuclear triad and strengthens U.S. strategic deterrence. The Trident II is considered to be a durable sea-based system capable of engaging many targets. It has payload flexibility that can accommodate various treaty requirements, such as New START. The Trident II's increased payload allows nuclear deterrence to be accomplished with fewer submarines, and its high accuracy—approaching that of land-based missiles—enables it to be used as a first strike weapon.
The eleventh HMS Vanguard of the Royal Navy is the lead boat of her class of Trident ballistic missile-armed submarines. The submarine is based at Faslane, HMNB Clyde, Argyll, Scotland.
His Majesty's Naval Base, Clyde, primarily sited at Faslane on the Gare Loch, is one of three operating bases in the United Kingdom for the Royal Navy. It is the navy's headquarters in Scotland and is best known as the home of Britain's nuclear weapons, in the form of nuclear submarines armed with Trident missiles.
HMSVictorious is the second Vanguard-class submarine of the Royal Navy. Victorious carries the Trident ballistic missile, the UK's nuclear deterrent.
HMSVigilant is the third Vanguard-class submarine of the Royal Navy. Vigilant carries the Trident ballistic missile, the United Kingdom's nuclear deterrent.
The Royal Navy Submarine Service is one of the five fighting arms of the Royal Navy. It is sometimes known as the Silent Service, as submarines are generally required to operate undetected.
The Triomphant class of ballistic missile submarines of the French Navy is the active lead boat class of four boats that entered service in 1997, 1999, 2004, and 2010. These four superseded the older Redoutable class, and they provide the ocean-based component of France's nuclear deterrent strike force, the Force de dissuasion. Their home port is Île Longue, Roadstead of Brest, Western Brittany.
The Dreadnought class is the future replacement for the Vanguard class of ballistic missile submarines. Like their predecessors they will carry Trident II D-5 missiles. The Vanguard submarines entered service in the United Kingdom in the 1990s with an intended service life of 25 years. Their replacement is necessary if the Royal Navy is to maintain a continuous at-sea deterrent (CASD), the principle of operation behind the Trident system.
Trident, also known as the Trident nuclear programme or Trident nuclear deterrent, covers the development, procurement and operation of nuclear weapons in the United Kingdom and their means of delivery. Its purpose as stated by the Ministry of Defence is to "deter the most extreme threats to our national security and way of life, which cannot be done by other means". Trident is an operational system of four Vanguard-class submarines armed with Trident II D-5 ballistic missiles, able to deliver thermonuclear warheads from multiple independently targetable re-entry vehicles (MIRVs). It is operated by the Royal Navy and based at Clyde Naval Base on the west coast of Scotland. At least one submarine is always on patrol to provide a continuous at-sea capability. The missiles are manufactured in the United States, while the warheads are British.
HMS Audacious is the fourth Astute-class nuclear-powered fleet submarine of the Royal Navy. Several previous vessels of the Royal Navy have borne the name. She was formally named on 16 December 2016 and was launched on 28 April 2017. Audacious was stated to be handed over in January 2021. A parliamentary written answer stated that Audacious was commissioned on 3 April 2020, but her public ceremonial commissioning took place on 23 September 2021.
Le Triomphant is a strategic nuclear submarine of the French Navy; the submarine is the lead boat of her class commissioned in 1997 with the home port of Île Longue. The vessel carries sixteen strategic missiles, whose launch can only be authorized by the President of France.
The submarines HMS Vanguard of the Royal Navy and Le Triomphant of the French Navy collided in the Atlantic Ocean in the night between 3–4 February 2009. Both nuclear-powered ballistic missile submarines sustained damage, but no injuries or radioactivity releases were reported. At the time of the collision, both vessels were submerged and moving "at very low speed" according to the UK Ministry of Defence. Both are equipped with active and passive sonar, although only the latter is used on an operational patrol.
United Kingdom 
