These are big boats in the sea. They stay under the water. They carry very strong tools. These tools help keep the land safe. They are very large. Can you imagine a boat under the sea?
These are huge boats under the sea. They use a special power to move. This power lets them travel very far. They can go around the world 40 times. They do not even need to stop for fuel. 

The Vanguard class is a group of four large submarines. 

The Vanguard boats are very big. They weigh nearly 16,000 tonnes. Because they are so large, a special building called Devonshire Dock Hall was built to make them. 
The Vanguard class is a group of four large submarines used by the Royal Navy. These vessels are known as nuclear-powered ballistic missile submarines. They serve a very important job for the United Kingdom. They carry the nation's nuclear weapons to help keep the country safe. This role is called a nuclear deterrent. This means the submarines are there to prevent conflict. The four boats in this class are HMS Vanguard, HMS Victorious, HMS altogether, and HMS Vengeance. 
These submarines work using a special kind of engine called a nuclear reactor. 
Building these massive boats required a lot of planning and new buildings. The design process began in the early 1980s. Vickers Shipbuilding and Engineering helped with the detailed design. Because the boats were so huge, a special building was needed. Engineers built the Devonshire Dock Hall in Barrow-in-Furness just for this task. Margaret Thatcher laid the keel for the first boat, HMS Vanguard, in 1986. The first boat was launched in 1992 and began its service in 1993. The final boat, HMS Vengeance, was commissioned in 1999.
The Vanguard class is very large and carries many different tools. 
Even though these boats are very advanced, they will not stay in service forever. The Vanguard class is scheduled to be replaced starting in the early 2030s. The new group of submarines will be called the Dreadnought class. These new boats will use a new reactor called the PWR3. The government has already planned for this transition to keep the nuclear program going. Building these new boats will be a very large project. It is expected to cost about £31 billion over 35 years. This ensures the United Kingdom continues its sea patrols for many years to come.
The Vanguard class is a group of four nuclear-powered ballistic missile submarines (SSBNs) used by the Royal Navy. These massive vessels serve as the United Kingdom's sole platform for its nuclear weapons. This role is known as a nuclear deterrent, which is meant to prevent conflict. The class includes four specific ships: HMS Vanguard, HMS Victorious, HMS altogether, and HMS Vengeance. They are based at HM Naval Base Clyde, located west of Glasgow, Scotland. These submarines are scheduled to be replaced by the Dreadnought class starting in the early 2030s.
Each submarine operates using a specialized propulsion system. They use the Rolls-Royce PWR 2, which is a pressurized water reactor. This reactor generates heat to produce steam. This steam drives two GEC steam turbines. These turbines are linked to a single shaft pump jet propulsor. This setup allows the submarines to reach submerged speeds of over 25 knots. The system is incredibly efficient for long-distance travel. It is estimated that one submarine could circumnavigate the entire world 40 times without needing to refuel. During long-overhaul refit periods, a 'Core H' reactor is installed. This ensures the boats never require further refueling for the rest of their service lives.

To navigate and detect objects, the class uses advanced sensory technology. They utilize the Thales Underwater Systems Type 2054 composite sonar. This is a multi-mode system that includes the 2046, 2043, and 2082 sonars. The Type 2043 is a hull-mounted active and passive search sonar. The Type 2082 acts as a passive intercept and ranging sonar. Additionally, a Type 2046 towed array sonar provides low-frequency passive search capabilities. For looking above the water, the boats carry two periscopes. These are the CK51 search model and the CH91 attack model. Both models include thermal imaging cameras and conventional optics to assist the crew.

The construction of these submarines was a massive engineering undertaking. The Ministry of Defence designed the class in the early 1980s. Vickers Shipbuilding and Engineering (VSEL) handled the detailed design at Barrow-in-Furness. Because the submarines were so large, a special facility was required. Engineers built the Devonshire Dock Hall specifically for this purpose between 1982 and 1986. Margaret Thatcher laid the keel for the first boat, HMS Vanguard, on 3 September 1986. The first vessel was launched in 1992 and commissioned in 1993. The final boat, HMS Vengeance, was commissioned in 1999.
Significant investments were made to support the entire program. Extensive redevelopment occurred at HMNB Clyde and the Royal Naval Armaments Depot Coulport. Rosyth dockyard also underwent major changes. These upgrades included improved facilities for handling, storage, and engineering. The estimated cost for these redevelopments was £550 million. Looking toward the future, the government is preparing for the Dreadnought class. This new class will use a new PWR3 nuclear reactor. The Ministry of Defence estimates the cost for the replacement program at £31 billion. This includes a £10 billion contingency fund over a 35-year period. The new fleet is expected to begin operations by the 2030s.
🖼️ Images & Media (3)
More to explore
✨ What else?
Related topics you might enjoy
🔬 Go deeper
More advanced topics to explore
🪜 Step back
Simpler topics to build understanding
What is Nepedia?
A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.