The Dreadnought class will replace the Vanguard class submarines from 2028 onwards and will host the United Kingdom’s nuclear deterrent.

The United Kingdom’s nuclear deterrent today is hosted by the Vanguard Class submarine. The class has been purpose-built as a nuclear powered ballistic missile carrier, incorporating a selection of successful design features from other British submarines. Due to this it is quite unlike its predecessor, itself an adaptation of the Valiant class.

The Vanguards were designed and built by Vickers Shipbuilding and Engineering Limited at Barrow-in-Furness. They are by far the largest submarines ever manufactured in the United Kingdom and the third largest unit in the Royal Navy. A special manufacturing facility had to be purpose-built at Barrow for their construction.

The Vanguard Class submarines are larger than the Resolution Class they replaced mainly due to the need to accommodate the Trident D5 missile. However, the crew complement of a Vanguard Class boat is smaller – 132 officers and men compared to a Polaris submarine’s crew of 149. The newer boats include a number of improvements over previous British submarines, including a new design of nuclear propulsion system and a new tactical weapon system for self-defence purposes both before and after missile launch. The 16 tube missile compartment is based on the design of the 24 tube system used by the United States Navy’s Ohio Class Trident submarines.

In August 2003 it was ten years since the lead boat, HMS Vanguard had commissioned. In 2005 she returned to service after completing the first of the two Long Overhaul Periods (the first including a nuclear refuelling) planned during her service life.  She was designed with a twenty-five year hull life and thus was expected to require replacement by about 2019, but a less demanding operational profile and deployment cycle than originally anticipated will allow her projected service life to be extended to 2024 if required, and it seems like it will be.

As things stand today, the Astute project currently seems likely to end with the completion and delivery of the seventh hunter-killer around 2019, while the first Vanguard replacement is required in 2021.

Government approved initial gate for the Dreadnought submarine programme to replace the the Vanguard class in May 2011.

While details remain sketchy at best regarding the Dreadnought class, one of the key features the new boats will have is a Common Missile Compartment (CMC). CMC aims to define the missile tubes and accompanying systems that would be used to launch new ballistic missiles, successors to the current Trident II/ D5 missile fleet used by the USA and Britain.

As key trends like cheaper sensors, increasing autonomy and artificial intelligence march onward, the next 40 years will see big changes in the underwater environment. SSBNs will need the flexibility to adapt to these changes if they intend to survive.

For the USA and Britain, the CMC needs to be part of that adaptation. Key options under consideration include a widened diameter for each tube from 2.21m – 3.04m, and the potential for flexibility beyond nuclear missiles, this would provide incredible future-proofing while delivery a (to some unwise), multirole capability.

The British government took the first steps in 2006 towards a joint US-UK missile compartment and the project was launched in 2008, initial gate approval for Britain’s ‘Successor’ project followed in 2011. Other contracts have followed, covering design and even the new kind of nuclear reactor the submarines are expected to use.

There is a precedent for this in the United States, the Virginia Class Block III fast attack submarine replaced their 12 vertical-launch cruise missile tubes with 2 Common Weapon Launcher (CWL). The size of those CWLs allows Virginia Class Block III submarines to launch cruise missiles, UAVs, UUVs, and more from their tubes.

British and American collaboration will also benefit and informs the Dreadnought class missile capability. The 2010 Strategic Defence and Security Review stated the submarine will have eight operational missiles, carrying no more than 40 operational warheads between them. Furthermore, an important feature of the collaboration between the UK and the US has been collaboration between the UK and the US on the new and advanced PWR-3 pressurised water reactor nuclear.

PWR-3, representing the third generation of British pressurised water reactors, builds on cutting edge nuclear propulsion research undertaken by the MoD and Rolls-Royce in the last few decades and is rumoured to be at a very advanced stage of development.

The exact nature of the UK’s industrial access to US reactor technology remains largely unknown in the public domain, the Royal Institution of Naval Architects reported previously that it is likely that the UK has been given a good look at the S9G reactor design that equips the US Navy’s Virginia Class submarines.

Back to the missile compartments, there is no question that the future Common Missile Compartment will be built around the nuclear deterrence mission as its primary focus. That is unlikely to be its sole use, however, and it would not be surprising if some of those other potential uses ended up influencing the CMC’s design. As is the case with a force more focused on multi role capability, versatility is key. Industry is unsurprisingly quiet on the specifics of the engineering and technology but industry has given some intriguing glimpses at what we may see in the water, one day.

According to BAE, the lead partner for the Dreadnought programme, work on the concept design phase had been ongoing since 2007, but this has now completed, and an outline submarine design has been selected.

Following the Government’s approval of the Initial Gate Business Case in May, 2011, the programme moved into the Assessment Phase, which is the first major stage of the new submarine’s design and development. This is where the vessel concept and requirements are fleshed out and finalised into a detailed hull form and systems.

First Sea Lord, Admiral Sir Mark Stanhope recently commented that

“The Royal Navy has been operating continuous at-sea deterrent patrols for more than 40 years, the Successor submarines will allow us to do so well into the future with cutting-edge equipment.”

The project will now move into the next stage, known as ‘Delivery Phase 1’, with manufacturing work beginning on structural steel work for the ‘auxiliary machine spaces’ of the first submarine: this contains switchboards and control panels for the reactor.

The money will also be spent furthering the design of the submarine, purchasing materials and long lead items, and investing in facilities at the BAE Systems yard in Barrow-in-Furness where the submarines will be built.

Tony Johns, Managing Director of BAE Systems Submarines said:

“This additional financial investment by the MOD is an expression of confidence in our ability to build these sophisticated vessels.

We have been designing the new class of submarine for more than five years and thanks to the maturity of our design, we’re now in a position to start production on the date we set back in 2011.

This is a terrific achievement and I pay tribute to all those who have made this possible.”

With regards to cost, it’s expected that the Dreadnought submarines and their infrastructure will cost around £15 billion. This can be broken down as such:

  • £0.25 billion to participate in the Trident D5 missile life extension programme.
  • £11 billion for a class of four new submarines.
  • £2 billion for possible refurbishing of the warheads.
  • £2–3 billion for infrastructure (spent over 30 years).

There would be savings from a three-boat solution but these would not be in proportion to the reduction in the number of submarines.

“Of course, the deterrent is not cheap – no major equipment programme is. But our current nuclear weapons capability costs on average around 5-6 per cent of the current defence budget.”
David Cameron, the Telegraph, 4 April 2013

According to a series of statements made in Parliament by ministers of the MoD, the annual operating costs of the Trident programme will indeed be around 5 to 6 per cent of the defence budget.

This means that the replacement submarines will have a running cost of around £2 billion per year, that may seem high but in defence terms, it’s relatively low as a single Type 45 Destroyer costs close to £1 billion to purchase let alone operate and fully arm.

The current annual spend on Trident is equivalent to less than 1 per cent of current health and education expenditure, this figure will be roughly the same for the replacement.

Estimates of the long term costs of big capital spends are notoriously hard to predict and can often fall or rise drastically. The costs associated with the programme are comparable to the procurement costs of major weapons systems such as Typhoon or Lightning aircraft.

Assuming the new submarines have a service life of 30 years, how much will it cost to run the submarines over their lifespan? Around £60 Billion spread over 30 years.

When the initial procurement costs are added on, the total programme cost will an estimated £75 billion however, £60 billion of this figure, as mentioned earlier, is spread over the lifetime of the vessels.

The programme already employs more than 2,600 people across MoD and industry, including 1,800 at BAE Systems.

Thousands more will be employed in the supply chain with an average of 7,800 people expected to be working on Dreadnought each year throughout the duration of the programme.

At peak, in the early 2020s, BAE Systems anticipates employing more than 5,000 people on the Dreadnought programme.


  1. Surely the role and the strength of the ballistic sub is to remain undiscovered? Does not the idea of fitting conventional weapons such as Tommahawk cruise missiles through a CMC render this strength a weakness which could easily be exploited.

    The deterrence factor of the continuous at sea deterrent lies in its ability to seemingly strike from anywhere.

    Elsewhere on this site is a comparison between the new QE carrier and Russian carrier and it is stated that shoehorning two roles into one platform means you lose you ability to do each well. Why on earth would both the UK and the US be willing to make the same mistake?

    Utter lunacy?

    • Depends, if we have more than 2 ship at sea, one of them can be kept hidden and the other do more conventional operations such as launching tommahawks etc.

    • I think that is a little simplistic as usefulness of the flexibility will be very much dependent upon the World and Regional political situation at any given time surely, though admittedly with the increasing possibility of a new Cold War that is not presently headed in a positive direction. I would think the other point would be that it depends upon just how flexible and interchangeable the various elements/weapons using the CMC will be in reality. Surely if for whatever reason only some of those tubes are likely to be filled with ballistic missiles it would be only logical for others to be capable of being used with other options, especially if it means as needs change over its lifetime the submarine has a better chance of adapting to suit. The balance is clearly to achieve this ideal without compromising the whole package to any great degree. Over and above that then that flexibility I first spoke of is somewhat dictated by the tactical and practical nature of the submarine actually using those flexible assets it carries. Predicting that scenario even for its in service date let alone over its lifetime is almost impossible so as long as there is no overall technical negative effect on its prime function such new capabilities are welcome.

      I think that the big difference between this concept (at least as much as we know so far) and the Russian carrier is that the latter using considerable portions of its structure to give it those other strike capabilities (with men, machinery and somewhat obsolete electronic/sensor add ons to make it all usable). One would hope 30 years of progress and the inherently related functions of the type of assets within the tubes that will be there anyway of course, so take up no extra room, will not introduce similar compromises and space hits, suffered by the Admiral Kuznetsov. But no doubt time will tell for sure.

  2. I worked on the famous Oberon class submarines back in the 60’s for the Australians and Canadians, and reading all this about both Astute and Dreadnought warms the “cockles of my heart”. With Brexit happening I would like to see us taking the lead with the likes of Australia and Canada along with us as well (as we did in the 60’s). I feel the UK should be able to offer these closely related Countries the training and expertise to enable them to at least build their version of the Astute. The Australians are about to embark on building 12 unknown French designs after having failed with a previous Swedish design. The UK has an enormous technical advantage built up over many years in all Naval design and we ought to partnership these two Nations if we can (in a limited way ) to help offset some of these costs.

  3. I am confused as to the running costs as it cannot cost £2bn a year to run 4 subs that don’t need fuel (a major cost) and have a fairly low crew size.

    Once again – made up figures from government – I would suggest the 5% includes the full capital costs of the ships and its weapons and not just running costs as it really is virtually impossible to spend this much money on maintenance and operating 4 ships.

  4. I think as Parliament has voted for renewal of the nuclear deterrent, as we are a sovereign, free and democratic country we can spend our tax income how we like.
    The ballistic missle submarines assure any potential aggressor thinking about attacking the UK that we have a very big stick as a weapon of last resort.
    problem is the weakness of our conventional forces means a politician might reach for that weapon of last resort much quicker than previously thought necessary.
    The Vanguard class submarines were not purchased using core defence budget money and neither should the proposed dreadnought class. Building the dreadnought class should come out of a strategic separate budget.
    Could we not use this saving of the defence budget to order more astute class, a replacement for hms ocean, fitting mk41 vl systems on our type 45 destroyers and ordering more than 8 type 26 frigates? All of which is needed to resolve the dire mess the RN is currently in.