Naval Systems

Dreadnought-class submarine

Also known as
  • Dreadnought class
  • Dreadnought-class submarines
  • Dreadnought SSBN
  • Successor submarine
  • Successor SSBN
  • Royal Navy Dreadnought class

The Dreadnought-class submarine is the Royal Navy's four-boat replacement for the Vanguard-class strategic-deterrent force, designed and built by BAE Systems at Barrow-in-Furness with the Dreadnought Alliance. The class is a future nuclear-powered ballistic missile submarine platform for Trident II D5 missiles, with the lead boat's keel laid in March 2025 and service planned from the early 2030s.

Dreadnought-class submarine, Nuclear-powered ballistic missile submarine, Naval Systems
Image source: Rendering of Dreadnought-class submarine.webp
Profile / Specs

Profile

Origin
United Kingdom
Built by
BAE Systems
Type
Nuclear-powered ballistic missile submarine
Service note
Under construction; planned Royal Navy service from the early 2030s
Produced
2016-present
Number built
4 planned; under construction

Specifications

Planned class size
4 submarines
Length
153.6 m
Builder location
Barrow-in-Furness, Cumbria
Propulsion
Rolls-Royce PWR3 pressurised-water reactor
Missile fit
12 Trident 2 D5 missiles in three missile compartments
Torpedo tubes
Four 533 mm tubes
Sensor fit
Thales Sonar 2076 and Combat System Mast
Control system
BAE Systems Active Vehicle Control Management fly-by-wire controls
Build complexity
26.4 miles of pipework and more than 20,000 cables totaling 215 miles per submarine
Class Boat Plan

The class is planned as four Royal Navy ballistic-missile submarines built at Barrow-in-Furness to sustain the United Kingdom's continuous at-sea deterrent as Vanguard-class boats retire.

BoatProgram statusCatalog context
HMS DreadnoughtLead boat; keel laid in March 2025.First boat of the class and planned Vanguard-class replacement from the early 2030s.
HMS ValiantSecond boat; construction work identified by BAE Systems as underway.Part of the four-boat deterrent replacement programme.
HMS WarspiteThird boat; steel cut in February 2023.Marks continued build progress at BAE Systems' Barrow shipyard.
HMS King George VIFourth named boat in the planned class.Completes the named four-submarine Dreadnought-class plan.
Sensors And Control

The Dreadnought programme pairs the Trident launch role with updated submarine sensor and control systems rather than treating the boat only as a missile container.

System areaSupplier or sourceReader context
Sonar suiteThales Sonar 2076Royal Navy reporting says all four boats will receive Sonar 2076, including bow, flank and towed-array systems.
Above-water sensorsCombat System MastThe same Royal Navy source describes updated digital periscope masts for visual and situational awareness.
Manoeuvring controlsBAE Systems AVCMBAE Systems describes the Active Vehicle Control Management system as adapting flight-control technology to manage heading, pitch, depth and buoyancy.
Ballistic Missile Armament

Royal Navy material identifies the Dreadnought class as the successor ballistic-missile submarine platform for Trident II D5 missiles.

Launched itemItem typeLaunch evidence
Trident II D5 fleet ballistic missile, Submarine-launched ballistic missile, MunitionsTrident II D5 fleet ballistic missileSubmarine-launched ballistic missile

The Royal Navy says Dreadnought-class submarines will be capable of launching Trident 2 D5 missiles as they replace the Vanguard-class deterrent boats.

Sources: Royal Navy Dreadnought class

Timeline

Dreadnought-class submarine Key Events

  1. Lead boat and class named Dreadnought

    The Ministry of Defence announced that the first Successor submarine would be named Dreadnought and that the name would become the class name.

    Sources: New Successor Submarines Named

  2. Warspite steel cut

    The Ministry of Defence and Submarine Delivery Agency reported that steel had been cut on Warspite, the third of four Dreadnought-class submarines.

    Sources: Nuclear submarine steel cut milestone

  3. HMS Dreadnought keel laid

    BAE Systems announced that the keel of the first Dreadnought-class submarine had been laid at Barrow-in-Furness, with the final major unit preparing for integration.

    Sources: BAE Systems Dreadnought keel laid

Media

Dreadnought-class submarine Videos

Dreadnought-class submarine Images

Dreadnought-class submarine, Nuclear-powered ballistic missile submarine, Naval Systems - view 1
Source: Successor SSBN infographic.jpg
Related Weapon Systems
Vanguard-class submarine, Nuclear-powered ballistic missile submarine, Naval SystemsNaval SystemsVanguard-class submarineNuclear-powered ballistic missile submarineThe Vanguard-class submarine is the Royal Navy's four-boat nuclear-powered ballistic missile submarine class for the United Kingdom's continuous at-sea nuclear deterrent. Built at Barrow-in-Furness by Vickers Shipbuilding and Engineering, the class carries Trident II D5 missiles, remains in service as the UK's single nuclear delivery platform, and is being sustained until Dreadnought-class submarines replace it in the 2030s.
Ohio-class ballistic missile submarine, Nuclear-powered ballistic missile submarine, Naval SystemsNaval SystemsOhio-class ballistic missile submarineNuclear-powered ballistic missile submarineThe Ohio-class ballistic missile submarine is the U.S. Navy's current sea-based strategic-deterrent SSBN class and the launch platform for Trident II D5/D5LE missiles. Four early Ohio hulls were converted to SSGNs, leaving 14 SSBNs in strategic service; Navy sources describe each remaining SSBN as carrying up to 20 missiles after New START tube deactivation and operating on alternating Blue and Gold crews for sustained patrol availability.
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Type 094 / Jin-class ballistic missile submarine, Chinese People's Liberation Army Navy nuclear-powered ballistic missile submarine class, Naval SystemsNaval SystemsType 094 / Jin-class ballistic missile submarineChinese People's Liberation Army Navy nuclear-powered ballistic missile submarine classThe Type 094 / Jin-class is the People's Liberation Army Navy's operational nuclear-powered ballistic missile submarine class and China's first credible sea-based nuclear-deterrent platform. U.S. defense reporting describes six operational Jin-class boats carrying up to 12 JL-2 or JL-3 submarine-launched ballistic missiles, while open-source references place construction at Bohai Shipyard in Huludao.

Sources

Royal Navy Dreadnought classPublisher: Royal Navy | Note: Supports Dreadnought-class background, Royal Navy service context, and Trident 2 D5 launch capability. | Accessed: 2026-06-29BAE Systems DreadnoughtPublisher: BAE Systems | Note: Supports manufacturer background, Barrow construction context, fleet size, boat names, and platform dimensions for the Dreadnought-class submarine. | Accessed: 2026-06-29New Successor Submarines NamedPublisher: Ministry of Defence | Note: Supports the 2016 naming of the lead boat and Dreadnought class, construction-start context, and future deterrent framing. | Accessed: 2026-06-29Nuclear submarine steel cut milestonePublisher: Ministry of Defence and Submarine Delivery Agency | Note: Supports the Warspite steel-cut milestone, four-boat class list, approximate service-entry timing, Barrow construction, and length, pipework, and cabling details. | Accessed: 2026-06-29BAE Systems Dreadnought keel laidPublisher: BAE Systems | Note: Supports the 20 March 2025 keel-laying milestone for HMS Dreadnought, Barrow construction, Vanguard replacement context, and Dreadnought Alliance delivery structure. | Accessed: 2026-06-29Royal Navy Dreadnought eyes and earsPublisher: Royal Navy | Note: Supports Thales Combat System Mast, Sonar 2076, and the eyes-and-ears sensor context for the Dreadnought class. | Accessed: 2026-06-29BAE Systems Dreadnought fly-by-wirePublisher: BAE Systems | Note: Supports Active Vehicle Control Management and BAE Systems' adaptation of flight-control technology for Dreadnought submarine manoeuvring. | Accessed: 2026-06-29Rendering of Dreadnought-class submarine.webpPublisher: Wikimedia Commons | Note: Image provenance and licensing context for the primary Dreadnought-class render used on the entry. | Accessed: 2026-06-29Successor SSBN infographic.jpgPublisher: Wikimedia Commons | Note: Image provenance and licensing context for the supporting Dreadnought-class infographic used in the gallery. | Accessed: 2026-06-29