Thoughts on Trident


As m’learned friend Jedibeeftrix eloquently states in his recent takeon Sir Nick Harvey’s comments on Trident, the ex defence minister has managed to get the Trident replacement issue back into the news agenda in an intelligent way, not framing it in terms of having it or not but instead talking up the Liberal Democrat Trident Alternative Review, or the department of cheaper deterrents as it is more commonly known.

Whether this is a genuine attempt at seeking greater value for money or a simple ruse to obtain disarmament by other means is to some degree irrelevant, a range of decisions on a replacement for both the Vanguard class SSBN and Trident missiles will be needed, some sooner than others.

The Successor SSBN and Trident missile are completely different programmes with different timing (fortunately or unfortunately depending on your perspective) but of course are inextricably linked.

All the usual industrial, timing, cost and technology issues are open for discussion but uniquely, the nuclear deterrent has a significant ethical, political, Scottish independence and party political elements also and this makes the job of picking through the various strands of argument that more difficult.

If one were to look at the nuclear deterrent rationally it would be completely obvious that the very notion is insane, wasteful of precious resource and should be consigned to the round filing cabinet as soon as possible.

The problem is though, and this is something that those seeking its withdrawal never seem to appreciate, it is entirely because it is irrational, insane and emotional that it makes absolutely perfect sense.

However, it is still worth exploring that difficult ‘why’ question

To state the obvious, we are not in the cold war and it is this charge that is often levelled at a Trident replacement, we are arguably more likely to face a nuclear attack tomorrow from a smuggled and deniable dirty bomb than a ballistic missile with an obvious track and origin. The type of country that might back such an attack is arguably unlikely to be deterred by Trident because they could just shrug and say ‘it wasn’t us’

Retaliation then becomes a difficult prospect, against whom?

In this scenario, our multi billion pound weapon system would stand mute and impotent.

The obvious counter to that argument is that whilst this might be true today, with the speed of technology proliferation can this be guaranteed for the next 30-50 years, I think not. One only has to look at the speed at which India, Pakistan, North Korea and Israel have acquired warhead and delivery technology.

Emerging nuclear powers like Iran have also shown an ability to make deals and use their indigenous capabilities to progress at a rapid pace.

It would be an extraordinary gamble to throw away a capability that has taken so much effort to achieve and others are racing at full speed ahead to get. The Non Proliferation Treaty has proven to be spectacularly ineffective at stopping these nations and the technology is clearly transferable. So whilst it is highly unlikely that we will face a nuclear threat or attack from the current nuclear states can we predict with any certainty that either these threats will remain low or new ones will not emerge?

We might also be tempted to look at the issue through the prism of a Western democratic liberal prism, the world unfortunately is not altogether a rational place that shares our values. Whilst this does not mean those with differing values are hell bent on our nuclear destruction it illustrates that we should be careful about seeing things from one angle only.

The argument about the nuclear terrorist attack also assumes that this is the only possible future, yes Trident may be a relatively poor deterrent against a nuclear capable AQ but do we seriously think that is the only threat we face for the next 40 or 50 years?

It is this inability to see into the future, basic uncertainty about the threats to the UK that should be driving our thinking.

In addition, there are a range of benefits that accrue from being at the so called ‘top table’ and it is these that also have to be factored in.

One of the Think Defence gang came up recently with a great comment about the ‘top table’

People talk of us just wanting to keep a seat at the table like it was a sodding dinner party or something.

You tell me who has more influence, the blokes sat around the table in the board room or the blokes sat in the company canteen?

Nuclear weapons are not the only reason the United Kingdom has a place at that table but it is one of them.

It is fashionable to decry the United Kingdom’s Great Nation status, talk of being a small nation in a big continent, a declining wealth in comparison to emerging nations and a collective imperial guilt complex but this needs to simply stop.

Of course we have to be realistic, the nation’s influence and power are declining in some areas but we are not a ‘little people’ just yet and shouldn’t be talking about ways and means of making us thus even faster.

So, on the ‘should we shouldn’t we’ question I am still very much of the opinion that the UK should retain its nuclear weapons delivery capability.

Moving on from that ethically and politically charged question the final issue to address is the ‘how’

The reason the ‘how’ is in the news is because the UK is facing the need to renew the equipment used to deliver nuclear deterrent and quite simply, we are facing a significant financial crisis.

Can we deliver a credible nuclear deterrent cheaper than a simple like for like replacement of the current system?

This then raises the question about what exactly does deterrent mean, against whom, what would be the definition of credible and other interlinked questions.

A credible deterrent in its simplistic form means the other guy has to know that you have the means to hit back no matter what and the balls to do so.

If the UK was attacked (or any other typical trigger scenarios) I do not believe any Prime Minister would shy away from the decision to retaliate with nuclear weapons, history would judge him harshly.

To be credible that deterrent has to be capable of being used at short notice, have a devastating impact and immune from a first strike.

It is this issue that Sir Nick Harvey has raised, can we have a credible deterrent on the cheap.

As much as I am rather scornful of Liberal Democrat defence policies I think this is an entirely valid question to ask, even though some of the commentary around that question seems extreme.

The programme to replace Trident and the Vanguard submarines had been bumping along quite nicely but the comments by Nick Harvey at the recent Liberal Democrat Party Conference have thrown an interesting spin on the Successor SSBN programme and will I am sure, put the issue firmly on the front burner again.

In an articlein the Guardian (of course) he makes a number of remarks;

First he starts by saying that Trident and a continuous at sea SSBN was based on the policy of ‘flattening Moscow’ but Russia being a different country now might be deterred by having an ability to flatten just a teensy bit of Moscow.

The Russia of the 21st century – economically diverse, vaguely democratic, but definitely a very different sort of place from where it was in 1980 – might find all sorts of damage to be unacceptable short of flattening Moscow.

Therefore to convince ourselves that the only point of having any deterrent at all is the capability of flattening Moscow is the wrong and distorting lens through which to view the debate

When I read that I did wonder if my late night trip to the Stella fridge was having a greater effect than usual but having re-read it, I was right, he really is saying we must base the fundamental means of deterring nuclear powers from attacking the UK on what Russia finds an unacceptable loss right now, at this point in time.

How would we know what they find unacceptable, should we just ask them, would we believe the answer, who would we ask?

The whole premise is ludicrous.

The thing is, for many years the Successor SSBN and Trident replacement programme has actually been based on a reduced number of missiles and reduced number of warheads anyway, with the Successor SSBN designed to carry eight missiles  instead of the Vanguard’s sixteen.

In terms of missiles carried we already plan to reduce by 50%.

Nick Harvey then described an alternative ‘delayed launch’ model that might include a nuclear armed cruise missile that would be stored until required in response to an emerging crisis.

but having perfected that technology simply put it away in a cupboard and keep it as a contingency in case there ever were to be a deterioration in the global security picture that might need the UK government to take it out of the cupboard

Nuclear weapons in a cupboard and asking the Russians what part of their country that would really really mind us flattening, seriously, I know the Liberal Democrats are often seen as being a bit wet but this takes things to a whole new level.

What a preposterous notion that is as wet as an otter’s pocket.

Finally, he indicates that a lower cost method has support within the armed forces because they see their respective sacred cows under threat from the Trident replacement programme .

Believe you me there are very senior figures of all three services who are highly aware of that perfect storm of these costs, who don’t believe the Treasury is going suddenly ride to their rescue with a cheque and who are asking, ‘Is the opportunity cost of having another generation of nuclear weapons too high, in terms of what it would prevent us doing on other fronts?’

I can’t say with certainty how they [military chiefs] will respond, but a number of them made the point to me to not portray it [the report] in such a political and party way that you don’t create the space for some of us to support you and try and help.

That the service chiefs are indicating they would be willing to sacrifice the current form of the nation’s nuclear deterrent in order to spend on the latest shiny conventional baubles is pretty revealing in itself.

Frankly, Trident replacement is a political decision that the MoD and services implement, it really isn’t up to them.

Broadly speaking there are two elements to the deterrent programme, a successor to the Vanguard submarines and a replacement for the Trident II D5 missiles and the warheads they carry.

Successor SSBN

Successor SSBN is a £25 billion multi-year programme that will be delivered in 2028(ish) to replace the current Vanguard class.

HMS Vanguard SSBN Trident
HMS Vanguard SSBN Trident


The Vanguard class comprises four nuclear powered submarines, Vanguard, Victorious, Vigilant and Vengeance.

Initial Gate was in 2011 and ‘things’ have since started to pick up the pace with enabling contracts awarded. The main industrial partners are BAE Systems, Rolls Royce and Babcock and between the three contractors have so far been awarded contracts to the value of about £350 million for initial research and design work. These initial contracts were also joined by a large £1.1 billion contract for Rolls Royce for the development and production of a new reactor, the PWR3.

The UK Nuclear Propulsion Programme (NPP) has been running since 1954 and delivered propulsion systems for all British nuclear submarines.

PWR1; Valiant, Churchill, Resolution, Swiftsure and Trafalgar classes

PWR2; Vanguard and Astute classes

Those two propulsion systems have supported over 30 million miles of ‘steaming’ from 1966 to the present day and the latest design of PWR2, CORE H, provides a large improvement most significant of which is the elimination of the need to refuel during the submarines life.

Pressurised Water Reactor 1 to 3
Pressurised Water Reactor 1 to 3

PWR3 will provide reduced noise, improved safety and cost reductions over Core H PWR2.

NPP has a long history of cooperation with similar USN programmes and has benefitted significantly.

Rolls Royce employs approximately 2,000 people across Derby, HMNB Devonport, HMNB Clyde, Bristol, Barrow in Furness and HMS Vulcan (Naval Reactor Test Establishment) at Thurso.

The submarine itself will be built by BAE Systems in Barrow, employing approximately 1,500 people.

Current assumptions are for PWR3 powered ‘Derived Astute’ with a Common Missile Compartment.

The design will be larger than the Vanguard class, even though it will carry fewer missiles, in order to accommodate improved systems and habitability.

The Successor design is likely to be very conservative, developing new where necessary, desirable and doable (communications, power, batteries etc) but pulling through as much technology from Astute as possible, for example, sensors and combat management systems.

Successor SSBN
Successor SSBN

In order to house the Trident missiles and whatever comes next, the UK and USA have been cooperating on the design for a Common Missile Compartment.

The CMC is an interesting piece of collaborative design designed to provide a modular fit option with the Successor likely to carry only eight tubes in although the Initial Gate Report said this;

Our successor submarines will have only eight operational missiles but it is clear from work to date that the cost of the missile compartment will be minimised by keeping as much of the design as possible common  with the US. The baseline design for the CMC is a 12 tube  unit and work is ongoing with the US to look at how best  to include our requirement for eight operational missiles into this design.

Early this month the design for CMC was finalised;

This document marks significant forward progress for both the U.S. and UK future strategic submarine deterrent programs,” said Brougham. “It is a direct result of the engineering rigor and professionalism of government and industry partners on both shores of the Atlantic.

Ship specifications are critical for the design and construction of the common missile compartment, which will be used by both nations’ replacement fleet ballistic missile submarine (SSBN) programs.  Specifically, the First Article Quad Pack Ship Specification establishes a common design and technical requirements for the four missile tubes and associated equipment that comprise each quad pack.

You could draw a number of conclusions from that, the easiest being that the CMC is modular in blocks of four. It might not be though and the quad pack could equally be an insert for a 12 tube outer, who knows?

A decision on 3 or 4 submarines will be taken in 2016.


The Successor SSBN will carry the existing Trident II D-5 missile, that of course being entirely the point.

The UK uses a shared pool of missiles with the US Navy and our own warhead design. The missiles themselves are being life extended to approximately 2042, co-terminus with the expected out of service life of the USN Ohio class of submarines.

This upgrade and life extension programme includes a new guidance package and upgraded re-entry system.

The current missiles (even if they are life extended) therefore, will be used on the new submarines.


SDSR 2010 stated that Successor will carry up to eight missiles and a maximum of forty warheads, from a reduced pool of both.

HMS Vulcan
HMS Vulcan

8 missiles would still provide a range of options and retaliatory striking power, whether that is a single low yield warhead or the full quantity of twelve independently targeted high yield warheads.


The current working assumption then is for a fleet of 3 or 4 Successor SSBN’s that will be of a relatively low risk design (excepting PWR3) deriving much from Astute, carrying 8 missile launch tubes to the CMC design and utilising a reduce pool of missiles and warheads.

The Trident Alternative Review, headed by the Liberal Democrats, will report on alternative, and one would assume lower cost, alternatives to those plans.

This is pretty interesting because there are many combinations and permutations of systems and doctrine that might combine to produce such a low cost solution;

Reduce the number of boats but still maintain CASD

The PWR3 design will not need refuelling and combined with other modern systems the system engineering derived availability will be much greater. Maintaining continuous availability at the same level of risk might be possible with Successor.

Even if that exact same level of availability cannot be maintained accepting a marginal increase in risk against a modified doctrine would no doubt produce some savings in equipment and running costs but taken across the whole programme over the whole lifetime would those savings be worth the risk or implications of changing the doctrine?

Reduce the availability model

This is somewhere between the RUSI Option 1 – A Normally CASD Submarine Force or Option 2 – A CASD Capable Submarine Force.

The UK’s deterrent is based on the simple model of assured availability, this being the reason our Trident missiles are currently lurking somewhere underwater. They are highly resistant to detection and provide a very fast retaliatory capability against a first strike.

If we accept that the Cold War model of being on a hairpin trigger is no longer valid we might still chose to utilise the submarine launched ballistic missile system but publically state that they may or may not be at sea. This would create some doubt in the mind of potential attackers, sufficient to make them think twice.

A reduction in boats and missiles might be possible with this model but again, would those savings be worth it and given the difficulty in concealing boat sailings it would not be an impossible intelligence task for an enemy to determine whether we were loaded or not and they would easily be able to call our bluff.

Availability could be flexed in response to strategic threats as needed within the constraints of however many boats we produced.

Alternative delivery options

We could always develop our own penetrating cruise missile with growth potential against increasingly sophisticated integrated air defences, a new warhead design, test that new warhead, invest in an army of lawyers and diplomats to deal with the non-proliferation issues of creating an entirely new means of delivering an entirely new nuclear warhead, ensure that should we wish to deploy it put the means of delivery into potentially predictable launch areas and then deal with the possible issues of people wondering whether we were lobbing a conventional or nuclear missile at them.

We might like to ask our nice friends in the US if we could buy a few nuclear land attack cruise missiles but would they still be in service for the lifetime we need, would we be the only user, would we need to consider the proliferation issues of obtaining a new system and would it actually save anything significant.

In 2010 the US announced the phasing out of the nuclear TLAM that would be completed in the following couple of years

We reached a point of mutual confidence that the [Tomahawk] was a redundant system not necessary for effective, extended deterrence

Principal Deputy Defense Undersecretary James Miller

Perhaps the most sobering aspect of using the TLAM-N is the simple fact that during Operation Iraqi Freedom in 2003 some ten (1.5%) of conventional missiles were lost, crashing into Saudi Arabia, Iran and Turkey.

Consider that for a moment and compare it against the not insignificant number of test firings of Trident that have achieved a 100% success.

Read more about the TLAM-N if you really need convincing it is not a good idea, click here.

If TLAM-N is not a practical option then we would need to develop not only a missile but warhead as well, test BOTH, develop a support infrastructure, train everyone, completely change our approach and withdraw Trident all before the V Boats go out of service

Oh, and all on our own because no one else is in the market for a system like that, not that we would sell it anyway.

None of the alternative delivery options are convincing from a cost, effectiveness or legal or simply timing perspective.

The cupboard option

As above, we would have to develop everything on our own and then put it into a cupboard, or defensible location.

Neither cheap, cost effective nor a deterrent to anyone; in short, a typically idiotic Liberal Democrat idea that has not been thought through but sounds good in conference season

The RUSI Option 4 – Non Deployed

Or put another way, concentrating your risk in a physical location.

If one is so inclined and decided to go and burgle someones house what would make you think twice as you look through the front window?


Gub Cabinet


Or this



Dual use submarines

This envisages a fleet of submarines that carry launch tubes but could also be used for other purposes with the long term rationalisation of the submarine fleet into a single dual role design.

This commonality would reduce the cost significantly and would allow the submarines to utilise the launch tubes for other systems such as cruise missiles or special-forces.

I quite like this option, but with one VERY IMPORTANT caveat and that is the mission of providing the at sea deterrent should never ever be mixed with anything else.

We might use the same boat design, or at least the same sub systems, which would provide commonality savings but the notion that the same ship could safely provide the deterrent on one day and then just nip inshore for a spot of land attack cruise missile launching the next is another preposterous idea.

I have seen this argued on blogs but I don’t think anyone is seriously considering it.

A Few Thoughts

The nuclear deterrent is a multi-decade insurance policy that we dabble with at our peril.

Pushing the Trident replacement costs into the MoD’s Core budget was a cynical act by the coalition government and if it is at all serious about the issue it needs to show political leadership by committing fully and backing with a separated funding stream.

Yes, we are not in the Cold War any more but equally we have proven rather ineffective at looking into the future and we cannot create a UOR for a deterrent.

That said, Successor recognises the change in the threat landscape and will carry 50% fewer missiles than the V Boats

The economic factors that are driving discussion on cheaper alternatives are cyclical in nature and it is unwise to base that insurance policy on short term economic factors.

It is not unreasonable however, to see if we can shave the cost whilst still maintaining credibility and an effective system.

PWR3, systems reuse from Astute and the D5 life extension programme provides the potential to look seriously at the risk profile of using 3 boats instead of 4.

Following on from Successor we might even be able to create a single class of submarines that can do either role with pull through from the work on the common missile compartment but that is far into the future.

The idea of reducing the scope of the CMC fit to 4 missiles in order to reduce overall size and cost is also worth considering.

For now, if the risk assessment provides some assurance, a 3 or 4 boat solution with Trident and a 4 or 8 missile CMC seems the only credible and sensible option with the choice of 3 or 4 down to the details.




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