Successor Submarine - Trident

A very big-ticket procurement programme, the Trident replacement is a major voice in terms of expenditure in the coming two decades. It is going to be a terrible burden on an already largely insufficient budget for defence, and it is a politically white-hot subject for countless reasons. I’m very much of the idea that Great Britain needs, now more than ever before, to maintain a minimum, credible, effective and survivable nuclear deterrent. This also because, with the conventional forces having shrunk so obscenely in the last twenty years, the nuclear arsenal is the last “big stick” left that separates the UK from nearly-irrelevance, keeping it in the very first major global players. At the same time, I could accept a cancellation of Trident, paradoxically, if most, if not all, of the 20 billions on ten years + 1 billion a year running cost of Trident were to be made available to strengthen conventional forces in exchange.
Sadly, this is not the case. Many advocate for a “kill Trident, fund the rest of the forces” approach, but I’m convinced that this is, to say the least, illusory. First of all because it will take tens of billions to terminate the nuclear arsenal, dismantle the submarines, dispose of the warheads, close the associate infrastructure, close down the nuclear establishment etcetera. It will cost thousands and thousands of jobs and billions and billions in end-game activities, while simultaneously having a far worse effect on the international relevance of the UK. It would spell the definitive end of an era, and condemn the UK to irrelevance. The long term savings of ending the Trident and the nuclear arsenal, besides, are (to say the very least) unlikely to effectively be injected back on defence. The chances are far higher that other departments will quickly swallow up the money, and the last remains will go on international aid, most likely.
The navy would also be exposed to long-term consequences, such as a perceived reduced necessity for SSN submarines and frigates, and cuts could follow cuts. Overall, the most cost-effective solution is to continue down the Trident path, for many reasons, that I will briefly expose, before beginning to look into the progress of the programme that will, hopefully, bring a new fleet of SSBNs in service in time to replace the Vanguards. 

Option 1 - Termination of nuclear arsenal   
This scenario is proposed as an example of goodwill from the UK in terms of global disarmament and abolition of nukes worldwide. Very poetic. But it does feel kind of like the agreements of Munich 1938: an hopeless dream. Are we really willing to believe that Iran will want a nuclear arsenal any less just because the UK gives up its own? If anything, the desire to possess a nuclear deterrence will grow higher.
It is also been told that it would be fitting for the UK to give up its nukes in light of the USA-Russia commitment to the “revolutionary” START treaty recently signed. People seems to totally overlook that while Russia is giving up 7000 nukes, both USA and Russia will retain over 1500 warheads each, with 700 launch vehicles from Sub-Launched missiles to road-mobile ICBM such as Russia’s Topol M. Hardly a disarmament, but merely an act of realism. Russia is unable to store and maintain 7000 warheads, and has no need at all for such a firepower made up by ancient tactical nukes meant to tear NATO apart in Germany. Honestly, even 1500 warheads are still probably far, far more than are justified.
In other words: more than disarmament, the START was a fancy political agreement that synchronized USA and URSS’s cost-cutting measures on their nuclear arsenals, so that a proper status quo of near parity could be maintained. Hardly a reason for anyone to feel like they do not need their own nukes.
By 2015, I personally expect to see Iran announcing they do have their first nukes. I may prove wrong, but I’d be surprised. I don’t believe in fairy tales, and none of UAE, Oman, Saudi Arabia and others up to obviously Israel believe in them either. In the coming years, nations that could develop a nuclear arsenal range from Iran to South Korea, which is long studying its options to get nukes to balance the North arsenal with a proper capability of answer. Even Japan, while constricted by politics and limitations imposed by the US, has not been untouched by considerations about getting nukes.
Reality is that nuclear bombs have been invented, built and tested and demonstrated. Once invented, they cannot be un-invented. And another truth is that when your neighbor, one with which you haven’t good relations either, starts producing and storing nukes, you feel compelled to build your own nukes. A scenario that could soon become reality in the Middle East.
I’ve already hinted to the cost, in terms of political weight, of money and jobs of a decision to terminate the UK nuclear arsenal. My opinion is that this option is good only for deluded, hopeless optimists. I expect nuclear proliferation to be quite widespread in the coming decades, and arguably a deterrent is more needed now than in 1970.

Option 2 - Replacing Trident with something “cheaper”

The options, considered so many times already in the years, are:

  1) A small force of vulnerable land based ballistic missiles, either road-mobile or silo-based. 
  2) Ship based ballistic missiles - probably a modified Trident missile at least at the start 
  3) Build a new class of SSBN's, initially carrying extended life Trident missiles and then the replacement submarine ballistic missile system. 
  4) Develop a cruise missile with a nuclear warhead, air launched by a force of 20 RAF strike aircraft supported by 20 dedicated refuelling aircraft.

The Submarine Deterrent has been the final blow which killed the Bomber force of the air force, and the RAF never really accepted it, as most FOAS concepts demonstrated well still in 2005. This image shows a Concorde turned into a strategic bomber jet (TSR2 resurrected!) and carrying 3 Blue Steel missiles. It was the proposal - already back then sold as 'relatively inexpensive' - the RAF made years and years ago to combat the Sub-Launched ballistic missiles. 


The RAF has made proposals for an Air-delivered deterrence replacement for SSBNs uncountable times. One proposal involved 20 Concorde turned into military supersonic bombers armed with stand-off, nuclear tipped missiles and supported by a dedicated force of air tankers for extended range operations.
How "relatively inexpensive" a fleet of 20 Concorde-bombers, 20 air tankers and cruise missiles and bases would have been is, i think, evident. Luckily, the submarine deterrent was recognized as most military and cost-effective solution. Yet, the RAF is still, today, advocating for a return of the strategic bomber force, with some success with the external public which fails to properly put things into scale.

Great Britain, during the Cold War, did also plan to have silo-based missiles. The plan of course quickly died. The UK is small and crowded, and find a suitable place to build nuke-silos in would be a non-starter. No one would want it, and it would be a never-ending messy saga of protesting, of studies, selection of preferred locations and subsequent dropping of them as they prove impossible to be used, either in a way or in another… And this without even considering the military aspect, with the evident vulnerability of fixed, well-known locations for a very limited number of missiles. No wonder that this option has always been dropped quickly.

Road-mobile missiles in the UK…? No way either. Russia has countless miles of nearly-desert lands where no one lives and where a Topol-M launcher can move and hide freely. How could the UK dream to keep a regiment of immense missile-launcher TELAR vehicles moving across the country from Scotland to Wales? It could never work.

Ship-based Trident. A bit less expensive than using submarines, perhaps, but it would still require the building of huge cruisers (which ideally would end up being nuclear powered) with extensive defensive suites to compensate their obvious vulnerability due to the "hey i'm here" nature of big surface vessels. The last nation which tried this was Italy, which built the cruisers Andrea Doria and Giuseppe Garibaldi during the Cold War with Polaris launch tubes. They were never given the missiles, however, since the US-supplied NATO-wide nuclear deterrent project soon died, leaving the ships with useless, huge empty tubes.

Then we get to the RAF’s favorite, the return of the V force. What airplane would be used…? A C17 launching huge missiles at altitude by having them parachute-extracted at altitude, or a stealth bomber or a hypersonic drone…? The RAF wants bombers, not cargo planes. And as much as the Concorde-bomber idea makes me drool, i'm totally convinced that it cannot work, and that it would be a total waste of money with the very real possibility of seeing it costing much more than the SSBNs.
Even cargo planes would likely be horrendously expensive. It would require designing new missiles, new launching methods, a fleet of “bombers” with an army of crews and a dedicate fleet of tankers for AAR. And it still would be inefficient and vulnerable to enemy attack, even more so because it would of course based on a single airport to save money. The only good part of this is that it might help the RAF getting more C17s that would (hopefully) be available for transport role most of the time.

Another option, overall the most realistic of the bunch of Trident alternatives, is to have a nuclear-tipped cruise missile capable to be launched from the Astute. The Tomahawk N however is gone, and it is very likely that the US would oppose a resurrection of it to be used by the UK: the Tomahawk is one of the most-heavily used weapons in the US and UK arsenals, and the political cost of having every single Tomahawk launch possibly mistaken for a nuclear attack is obviously inconceivable. Design a new missile would be a costly and challenging task, in particular if the most obvious limits of a cruise missile are to be tackled:

- Range
- Speed and survivability 

For a cruise-missile to be an effective deterrent capable to hit high-technology enemies (the only ones capable to start an attack requiring nuclear response, arguably) without being shot down should have the speed and stealthness to get past layered air defence systems. It should also have thousands of miles of range to enable the submarine to stay a safe distance away from the enemy.
A Stealth, Hypersonic Nuclear missile in the size constraints of a 533 mm standard NATO torpedo…? Pretty ambitious a development target. How many things could do wrong with it? How much work will the Astute need to be made capable to carry and employ safely nuclear weapons? How much operational constraints will come from having nukes on board? The risk is to have SSN submarines that instead of doing their job of aggression, attack, anti-submarine chase and TLAM launch, are forced to hide silently in the deep like SSBNs. In other words, a total failure.

But the most ridiculous option I heard suggested was “we can just keep the nukes, and scrap the missiles and submarines: the enemy will be prey of the doubts, not knowing if we can deliver the warheads or not”. I think this is ridiculous. Keeping Trident warheads would be plain absurd, and any military planner would know for sure that the UK could not deliver them anywhere. How could it, after all? From a Typhoon? The pilot throwing the warhead out of the cockpit with his hands, like in the First World War. Please. Let’s try and stay real. Even if the bomb WAS indeed made somehow portable by a plane… just like a Tomahawk-like cruise missile, we’d have the issue of range. The UK could retaliate against France, but against an enemy launching ballistic missiles with a range of 12.000 kilometers, what could be done? Nothing, unless there was a british submarine at any one time off the coasts of China, Russia, Iran and any other most-likely aggressor.

The last option, the “Doubt”, can be synthetized in: we can keep the mystery on the existence or not of our nuclear deterrent, like Israel does, and the enemy will be braked by the doubts.
Another ridiculous option. For Israel it might kind of work: we are talking about a probable 70 or so tactical nukes available for strikes from launching aircrafts. Good for Israel, that mainly has to scare off close neighbors. But the UK could really sustain this kind of deterrent? The first thing that comes to mind is: “British Press.” The secret about the existence of the nuclear deterrent would be lucky if it lasted a week, in the UK. And then comes logic: who would be fooled by such “mystery”? No one, I fear.  
All these options have a point in common: they fail miserably at the voice “credible”, while they (might) fill the “Minimum” and “Cheaper” requirements.

Nuclear policy: what the others do with their own nukes   

It is interesting to see what other nations do with their nuclear arsenals, and what’s their official policy about nuclear weapons use.

USA – With the START treaty, the nuclear arsenal of the US will go down to 1550 warheads and 700 strategic vectors of launch (ICBM, SLBM and bombers). In particular, the most valuable element of the arsenal will remain the 14 Ohio SSBN submarines, each with up to 24 Trident missiles. Up to 450 Minuteman III ICBMs will remain in service, fitted with single unitary warhead in place of the MIRV systems. The bombers B52 and B2 will not be in high readiness anymore for the nuclear role, that has grown largely secondary for them anyway. The new stealth bomber programme reportedly might lack the nuclear capability at first to keep costs down, while retaining the capability or being retrofitted for the role. The US Nuclear Posture Review of april 2010 states that the US will not use nukes against countries signatory of the Non Proliferation Treaty, even if these were to launch a chemical or bacteriological attack on the USA, to which is opposed a “devastating” conventional retaliation. The US, however, reserve themselves the right of a preventive nuclear strike against non-signatory countries like Iran and North Korea. The main role of the nuclear arsenal has been confirmed as deterrence to dissuade any enemy from launching a nuclear attack against the USA and its allies. The NPR document made clear that the effort of the US in the future, while contributing to putting a stop to proliferation, will be to ensure a nuclear umbrella of protection to their allies. It is thought that this is particularly valid for South Korea, that is seriously thinking about getting its own nuclear arsenal, something the US are keen to avoid by ensuring coverage. Taiwan is another example. 

Russia – modern Russia considers its extensive nuclear arsenal a “Gap-Filler” plugging closed the holes that still remain in its conventional military instrument. (holes that are however being all closed, with the budget for defence set to grow three times higher in the coming years and new acquisitions going on in every field, from stealth fighters to the 4 Mistrals to the recent buy from Italy of thousands of Lince, the base of the Panther CLV) Russia considers its nuclear arsenal the key to conserve parity with the US, despite having conventional armed forces that have been lagging heavily behind for many years in terms of equipment and readiness.
Russia’s white paper on the nuclear arsenals lists the nukes as key to protect the national integrity and safety, but it also announces that Russia reserves itself the right to use nukes to terminate/control any regional conflict growing complex enough to spur such an ultimate action.
In practice, the new Russia is using its nuclear arsenal as main key of its power, doing what NATO used to do in the Cold War: balance the greater (?) power of the possible enemies with the threat of use of nukes. In this sense, the (improbable to say the least) conventional menace represented by Europe is still listed by Russia as one of the main reasons for an eventual use of nuclear strikes, even preventive ones.
For this reason, Russia opposes so bitterly anything that is perceived as obstacle to the efficiency of its nuclear deterrence, such as the Anti-Ballistic defence plan of the US. And for this reason Russia continues the modernization of its arsenal, with the expansion of the road-mobile Topol-M regiments and the development of the advanced Bulava missile to deploy at sea.

France – Another very aggressive nuclear policy is France’s one. They officially reserve for themselves the right of utilizing of nuclear strikes to protect its interests, even against a terrorist attack and even through preventive attacks. France uniquely reserves itself the right to use nukes “demonstratively” to scare the enemy, for example by means of a nuclear explosion in the high atmosphere, with potential EMP effect.
The land-based ICBMs of France have been retired in 1996, but the air force still lines around 60 ASMP nuclear-tipped cruise missiles (carried often by carrier-based Rafales, and an obvious potential problem in future cross-decking of French squadrons on UK carriers) while the navy has around 60  M40 sub-launched ballistic missiles, progressively being replaced by the new M51 SLBM.

China – Nuclear power from 1964, China published the last version of its nuclear policy on 22 april 2010: the very recent document rules out any preventive use of nukes, listing the nuclear arsenal as a pure deterrent, almost comparable to the UK’s one both for sizes and for nature, being described as “Minimum Deterrent”.

India – Nuclear power from 1974, its official policy is of retaliation only, but the Indian nuclear arsenal is still capable of preventive strikes. Mainly the warheads are mounted on short and medium range ballistic missiles on road-mobile launchers. However, the nuclear arsenal is set to expand in the future, and plans for a fleet a SSBN already exist.

Pakistan – The nuclear arsenal was developed following the defeat against India in 1971, and to this day their nukes are specifically targeted at India. They are seen as a mean to balance India’s superior military capability, and Pakistan would officially consider using its nukes in support of operations of its conventional forces, specifically to destroy India’s forces.

North Korea – Effective consistence of the arsenal unknown. A nuclear test was first successful in 2006, and another one in 2009. From then onwards, North Korea has been menacing the use of nukes almost in every situation, and their policy appears to be a “we have them, and we will use them”.

Israel – Israel has never confirmed and never denied to have a nuclear arsenal. There’s uncertainty on its consistence, which is valued between 70 and 200 warheads, but there is general agreement on the fact that Israel does posses nukes. The nuclear arsenal is seen as the security of invulnerability against enemy attacks, but is reportedly considered as “last resource”: it has been suggested that the Israeli policy on nuclear weapons is a Samson policy that goes so far to envision the eventual self-destruction of Israel if it can mean destroying its enemies as well.
The nuclear arsenal grants Israel a wide autonomy of maneuver, making it largely independent from the US positions, and it has been observed that the consistent military aid given by the US to the country is apparently a mean to help Israel building such conventional military capabilities to ensure that there’s no need for a nuclear strike against the hostile neighbors.

Last, there are also a few countries who have been “examples” of disarmament, like someone would want the UK to act.

South Africa – In the 70s there has been an extensive nuclear programme, with a nuke tested in the Indian Ocean and at least 6 warheads having been reportedly manufactured. From 1989 South Africa dismantled its arsenal after signing the Non Proliferation act.

Ukraine, Kazakistan and others have been nuclear powers at the fall of the URSS, inheriting bombers, missiles and warheads that had been deployed on their soil. However, in 1993 they either dismantled or handed back to Russia their weaponry.

Their example has, unsurprisingly for anyone but the LibDems, had no effect at all on the worldwide nuclear proliferation trend.     

Syria and Iraq and even Libya  went close to appearing on this list, Iran might be the next doing it, and Saudi Arabia and other countries are reportedly already making it clear that they would feel compelled to develop their own nuclear deterrent in case Iran developed nukes. 

Japan, Taiwan and South Korea have also been seen, from time to time, as seriously contemplating the project of home grown nuclear deterrents to counter the menace of the nuclear powers nearby (North Korea and China). South Korea, Japan and Taiwan are, however, under the protection of the "extended" US nuclear umbrella offered by Washington to these allies specifically to avoid seeing them building their own nukes.

The UK Minimum Credible Deterrent

The UK's current nuclear deterrent capability comprises several elements: first, the nuclear warheads, which were designed and manufactured in the UK by the Atomic Weapons Establishment; second, the Trident D5 missiles, which were procured from the United States under the Polaris Sales Agreement (as amended for Trident); third, four Vanguard-class nuclear powered submarines, built at Barrow-in-Furness by what was then Vickers Shipbuilding and Engineering Limited, who also designed the bulk of the submarine; and finally a range of logistic infrastructure - at the naval facilities at Coulport (weapons handling and storage), Faslane (submarine basing) and Devonport (submarine refit and maintenance).

An impressive set of images from a Trident firing test. Note the "star-streaks" of the multiple independent re-entry vehicles which, in a live missile, would have carried the nukes. Their Mach 25 re-entry speed is good part of the reason why it is so hard to defend against a ballistic missile strike, even in the age of "missile shields".
The United Kingdom has purchased the rights to 58 Trident missiles under the Polaris Sales Agreement (modified for Trident) from a jointly maintained "pool". These missiles are fitted with UK-built warheads and are exchanged when requiring maintenance. Under the terms of the agreement, the United States does not have any veto on the use of British nuclear weapons. Some of the Trident missiles originally acquired have been fired in test launches, so the Vanguard submarines have never (and will never) have all of their tubes filled with missiles.
In fact, while the theoretical capacity of the four Vanguard-class submarines is 64 missiles and 768 warheads (16 missiles for each submarine, each missile carrying up to 12 warheads), only 58 missiles were leased and some of these have been expended in test firings. The UK leases the missiles but they are pooled with the Atlantic squadron of the USN Ohio SSBNs at King's Bay, Georgia (previously the UK maintained its Polaris missiles in-country). 

One vessel is always on patrol, one to two are in port or on training exercises and one is undergoing maintenance, in the practice known as CASD - Continuous At Sea Deterrence.

These vessels draw their warheads from a stock of available warheads ranging from 140 to 160, with a total of around 200 warheads. Nominally, there is around a 15% of spare warheads.  
The Trident is seen as a deterrent only, to discourage enemy aggressions on the UK and its allies. As such, it is configured as a retaliation system, capable to deal such terrifying damage to make any enemy hesitate. It is thus a “minimum” deterrent. 

But for it to work, it must be also “credible”: 
-          Trident has a range of over 10.000 kilometers, putting most of the possible enemies at reach and allowing the Vanguard SSBNs to patrol in safe waters not too far away from the UK. 
-          Trident is incredibly accurate, allowing to strike point targets such as enemy launching sites: its original role was to target and destroy URSS’s land ICBM silos, much as people brags about flattening Moscow. That was a role for Minuteman and bombers. 
-          Trident has an enormous destructive power, even when loaded with very few warheads. Monstrous as it is, it is what it has been designed for: if it wasn’t for its tremendous power, it would be useless. 
-          Trident is launched safely from the depths of the ocean, from the only real stealthy war machine man has engineered, the submarine. It is the most survivable of deterrents, and once a submarine is out at sea with its missiles, the UK is protected by having an effective capability for striking the offender back timely and devastatingly.

Trident thus is both survivable and effective. Minimum, while still credible. And it is arguably the only system that fits all the requisites.

Trident replacement: a closer look

a) The Warhead: 
The current warhead came into service with the Trident system in 1994. An extensive research programme to assure the safety and effectiveness of the warhead stockpile, coupled with the additional investment at AWE Aldermaston announced on 19 July 2005, gives a high level of confidence that the current warhead design can, if required, be maintained in service at least into the 2020s, with some relatively minor upgrading and refurbishment during the first half of the next decade .

The new target is to keep the warheads operative up to 2030.

b) The Ballistic Missiles: 
The Trident D5 missile came into service with the Royal Navy in 1994, with a planned life of some 25 years. The US Navy has recently announced plans for a life extension programme for the D5 missile, which will ensure it can remain in-service with the US Navy into the 2040s. The successor missile, which will carry fewer warheads but most likely offer an even greater range to put even more of the world under coverage (a necessity now that the target is not necessarily the URSS but an unknown potential future aggressor) will be a further development of the Trident, apparently named Trident E6. 

The UGM-133A Trident II D5 is the most sophisticate of the ballistic missiles developed by the West, and it was the most feared by the russians because of its unbeaten accuracy: the Trident was meant to be the first weapon launched in a pre-emptive attack, with the missiles targeted at the silos of the URSS's nuclear tipped missiles. With a CEP of 90 - 120 meters, the Trident warheads could have wiped out even the most deeply-buried and reinforced launch silos, potentially leaving the URSS incapable to respond (or at least respond in scale). Launched on a "low" ballistic course, from close distance, the Trident would have been detected too late to leave time for a suitable response. 

The "flattening Moscow" argument so often used against it is, therefore, historically not correct. Flattening cities was a work for bigger and dumber nuclear warheads, less accurate but more destructive (Minuteman missiles). Anyway, when talking about nuclear deterrence, and even more about nuclear war, "flattening Moscow" is the point of the whole matter. It has no sense to use it as an argument to bash at Trident: the missile will flatten the target it is ordered to strike.  

c) The Submarines: 
HMS Vanguard entered operational service with the Royal Navy in 1994, with the other three submarines in its class following in 1995, 1998 and 2001. The submarines were procured with a designed operational life of 25 years and on this basis, they would start to be withdrawn from service late in the next decade. A series of studies have considered whether it would be practicable and cost effective to continue to operate the submarines beyond the original design intent. All the studies confirmed that albeit with gradually increasing cost and some increasing risk of reduced availability, the Vanguard could go perhaps out to the mid-2020s, but now this target has been pushed further away, with HMS Vanguard bowing out in 2028 at the earlier, probably requiring a quite significant refit for each of the subs.

The Ohio class used by the US were built with a greater life expectation, and will not need replacement before well into the 2030s. This is a problem for the UK, that needs a new submarine before the US, but is late to count on French help, since they have instead just introduced new submarines and new missiles.
It is also significant that the US are already designing the successor submarine for the Ohio while knowing full well how far away in time the first build is. This is a telltale sign of how successive UK governments have ignored pointedly the warnings of admirals, engineers and experts, that have always made it clear that even a time such as 17 years is not unrealistic at all when it comes to design and build something as complex as a new SSBN class. Even drawing a longer life for the Vanguards, as long as possible, the risk is that technical difficulties and delays might force the Vanguards to soldier on for an unhealthy long time… or leave a gap between retirement of old and commissioning of new submarines.  

d) Shore Infrastructure: 
Under the Trident programme, successive Governments have made significant investment in the facilities at Coulport, Faslane and Devonport. We envisage that the facilities at these locations needed to support the nuclear deterrent will not require any significant additional investment to sustain them throughout the currently planned in-service life of the existing system. Clearly, the extent of any additional investment in logistics or infrastructure beyond that point will depend on future decisions on whether and how to maintain a nuclear deterrent beyond the planned life of the current system.

The SDSR 2010 has given just a few indications of a future that might even never be (how high are the chances of additional reductions in future, after all...?: 
-          Each replacement submarine will deploy with just 40 warheads on board, against the 48 of today. 
-          Each replacement submarine will have only 8 launch tubes, compared to the Vanguard’s 16.
-          The overall number of Available warheads will thus drop from 160 to no more than 120. 
-          Consequently, the total number of warheads will drop from around 200 (225 currently?) to no more than 180.

The new submarine: work in progress

The SDSR announced that detailed work on the new submarine’s design will start this year, but the UK is actually already involved in a very fundamental joint programme with the US: the designing of the Common Missile Compartment. As the SDSR confirmed specifically, already defined-details include an increased diameter from 2.21m launch tubes to 3.04m, allowing easier future use of the tubes for other roles (from multiple Tomahawk canister-launchers to drones to special forces gear) and integration of replacement missiles that, in the long life of the new submarines, could grow larger than current D5.
Converted Ohio class SSGNs have already replaced nuclear missiles with American special forces and land attack missiles, and the Virginia Class Block III fast attack submarine replaces 12 vertical-launch cruise missile tubes with 2 Common Weapon Launcher “six-shooters” derived from the SSGNs’ converted missile tubes. It provides an example of what could happen with some of the tubes of the future SSBN. The size of those CWLs will allow these submarines to launch cruise missiles, UAVs, UUVs, and more from these same tubes.
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.

However, it has been reported that the Common Missile Compartment will have 12 tubes each, as opposed to the current Ohio SSBNs’ 24, or the Vanguard SSBNs’ 16. This is in obvious contrast with the 8 figure reported by the SDSR. It is extremely unlikely, if not full-out impossible, that the US have changed their mind about the number they reportedly went for barely a year ago. So, either the UK compartment is “cut short” (but then it would not be all that Common, and it might be a stupid way to waste money in redesigning work which might also end up being source of delays, troubles and cost overgrowns) or four tubes will never be filled with Trident… which might not be a bad thing if they are used properly for other roles.
The US are reportedly already developing, between other things, a drone that can be launched from a submarine submerged and then fly its way to a target area and back for recovery. Even more readily available is the All Up Rounds Canister used on the two Trident-sized silos that replace the previous 12 single TLAM vertical tubes on the latest batches of USS Virginia SSNs. The All-Up Rounds Canister is already used on the Ohio submarines transformed in SSGNs by the US Navy, and it contains six or seven TLAMs. The converted Ohio carries up to 154 Tomahawks, while a UK SSBN might carry 4 x 7 = 28 TLAMs, plus easily 14 more launcheable from the torpedo tubes if the Successor SSBN will have the same weapons-capacity of the Astutes.
It is another indication of the possible future uses of such spaces. The end result might be a mix of SSBN and SSGN, combining nuclear and conventional deterrence by carrying Tomahawk missiles along with Trident.

The contract for the Common Missile Compartment was signed as far back as 23 December 2008:  General Dynamics Electric Boat Corporation, Groton, CT received a $75.6 million sole-source, cost plus fixed fee contract to perform concept studies and design of a Common Missile Compartment (CMC) for the United Kingdom Successor SSBN and the USA’s Ohio Class Replacement program. The contract included options which would bring the cumulative value of this contract to $591.8 million, and take design work to December 2013. The contract was not competitively procured, and is formally run through the Naval Sea Systems Command, Washington, DC (N00024-09-C-2100) while involving involves Foreign Military Sales to the United Kingdom. January 21, 2010, a first option was exercised, for 118.2 millions, with other options exercised subsequently, until 16 June 2010, when Northrop Grumman received a $148.6 million sole-source cost-plus-fixed-fee contract to work on the CMC’s advanced launcher development program for FY 2010-2011. Specific efforts included technical engineering services to support the common missile compartment concept development and prototyping effort. Lockheed Martin has then been contracted to ensure combatibility and integration of the Trident D5 missile with the new launcher, that is apparently proceeding rapidly. The effective amount of money provided by the UK for the joint programme is an information I do obviously not have, but the UK has been investing in the programme from 2008, when the development was started.

Rolls Royce has been contracted to prepare the Nuclear reactor core and the propulsion design for the new submarine, while Bae has been working on concept submarines from as far back as 2007. In order to keep costs down, however, an all-new submarine design has become unlikely for a Vanguard-class replacement and current thinking probably assumes an evolution of the Astute design. Indeed BAE Systems Submarines already examined two Astute variants fitted with an extra hull section a few years ago. The first included the fitting, external to the pressure hull, of sixteen Mark 36 Vertical Launch System tubes for missiles such as Tomahawk, and the second included four Trident II size (86 inch diameter, 36-feet usable length) missile tubes, installed aft of the fin.  The later approach is preferred as the large tubes are extremely versatile, alternative to Trident II SLBM’s they could potentially carry a next generation ballistic missile, a multiple all-up round canister accommodating seven Tomahawk cruise missiles per tube, equipment and swimmer vehicles for special forces, Unmanned Underwater Vehicle’s (UUV’s), deployable decoys and sensors, and even encapsulated Unmanned Air Vehicle’s (UAV’s).  While a re-role will not be trivial, the new submarines would certainly be far more flexible than the current SSBN/SSN divide permits.
While utilizing a modified Astute design to carry Trident has been much discussed for several years, officials of the Navy are continuing to make it clear that this is not a trivial exercise, at the very least a major and costly redesign will be required, so that no miracles should be asked from this approach.  The final result may have as much similarity to the Astute's as the Astute's (originally called Batch 2 Trafalgar!) have to the Trafalgars and Vanguards. It is still the most effective path to follow, probably… but don’t expect miracles.

Keeping costs down

This vital requirement is also the hardest met. The main chance to reduce cost is to drop the requirement for Continuous At Sea Deterrence, so to build only 3 submarines and have them at sea with a lower frequency, with considerable savings and less wear and tear on the hulls.
However, the CASD concept is the core of the whole deterrent: as unlikely as we want to consider it, it is self-evident that, with all the submarines in dock at Faslane, an enemy wanting to attack the UK would just have to target its first nukes at Faslane to completely kill any and every response capability. The whole point of the deterrence is to always have a submarine out at sea, ready to answer to an attack, and moreover making this attack impossible with its sole presence.
A CASD policy pretty much rules the number of hulls for the fleet, however: 4 is the bare minimum to ensure a constant presence, and both the UK itself and France have realized and accepted it. A recent accident which saw HMS Vengeance having to get back to Faslane under reduced power because of sea debris (possibly fishing nets) ending up in her propulsion system, proves that the unexpected is always on the headlines.
Besides, it is to be noted that the savings of building 3 hulls instead of 4 are very much relative: the fourth submarine is going to be the cheapest of the bunch, since it will benefit from the experience of the ones built before, and most of the cost will come from design and not from building.

It could still be attractive, however, to build only 3 submarines and ensure CASD through a collaborative approach instead of a strictly-national method. This is theorically possible by publically and officially announcing an agreement with France, in which would be possible declare that the patrols of UK and France submarines will be synchronized, so that a UK sub returning in port is replaced by a French submarine going out at sea. This would allow a reduced 3-boats fleet, and cut by half the number of sorties at sea per year for both fleets, while still ensuring a form of CASD. The problems, however, are significant: we can all accept that an attack on the UK of such a scale to justify nuclear retaliation would almost certainly be enough of a problem for France itself to react and vice versa… But even accepted this, there are political white-hot problems destined to emerge from such an agreement, in particular because, as I’ve earlier exposed, the Nuclear Stance of France is much more aggressive than the UK’s one. Would France be willing to review its policy, or wound the UK support France’s policy when on turn of patrol? Who will give orders to the SSBNs out at sea? Communicating with a sub is complex as it is. Communicating with it under nuclear attack might prove impossible. Coordinate orders between two countries, two ministries and two command chains and send the instructions to the sub is pretty much unthinkable.
Any such agreement, subsequently, poses such challenges that i believe it is very unlikely to go past suggestions, and mostly only has the potential to become a terrible mess.

Savings on missiles are not possible, since the current way of operating them is probably the very cheapest option as it is. It is thus hard to see other ways to save big sums and still deliver a realistic minimum credible deterrent. It already is very minimum, so cutting back further on it would make it not credible anymore. The reality is that the government, be it Con or Labour or whatever it will be by 2016, will have to come clear on the matter. The question is pretty simple, really: the UK wants to retain a place of relevance in the world and thus keep a nuclear deterrent? Fine, then it must be properly funded, and not by gutting the rest of the armed forces and see them bleed to death as piece after piece is cut off them. If the UK is not willing to keep its place anymore, then Trident is not needed. In terms of security, I guess the country could still claim to be under America’s own nuclear umbrella, or even under France’s. But it is better to think very carefully about it: South Korea is still internationally relevant, even without nukes of its own, because it is a growing economy in full ascension. The UK will not have this anchor: arguably, the Armed Forces are (were?) the only thing that still kept the UK in the top league. The government will respond of the long term setbacks coming from gutting that last element.

The case for Trident   

I remember reading a ridiculous comment about Trident, where someone had the smartness of observing: “We don’t need it. We’ve never used it, and never will!”. I did not know if I should have laughed of it, or cried. We should all be grateful that it never proved necessary to launch nukes on anyone after Nagasaki, but Trident has actually been used every single minute, day after day, year after year, from when it was put in service. The job of nuclear weapons like Trident is existing, and thus ensuring they are not used. That’s why we call it “deterrence”. I’m personally firmly convinced that the third world war in Europe was avoided merely because of the Mutually Assured Destruction concept: not the URSS nor the US wanted the world to be obliterated by nuclear fire, and by fielding their respective arsenals, they dissuaded each other from trying. 
Differently from the machinegun, which is probably the weapon who killed most men ever, the atomic bomb, despite being the deadliest of weapons by far, was never again used after the Japan strikes of the IIWW. This makes the nuclear bomb the most successful weapon ever: so terribly effective that no one has the courage of using it. Churchill wrote that Yalta’s meeting had the target of ensuring “60 years of peace” for Europe. It almost surely wouldn’t have been possible without the nuclear arsenals, and I highly doubt that a world without nukes would be that better: I like more a world held in overall-peace by the “balance of terror” than a world where there are no nukes but major conflicts between nations, in exchange, grow far more frequent. But maybe I’m just cynical. It is my idea. 

What I will always oppose is unilateral disarmament: giving up the nuclear weapons while more and more nations get them would perhaps be noble, but it would still be stupid. It would be like standing in a room filled with armed people aiming their guns at each other’s heads, and throw away your own gun.
Is it more likely they do throw theirs away… or that they exploit the fact of being armed while you are not to boss you around? 

As I said, I do not believe in happy fairy-tale land, and so I find I totally share the thinking behind the words of Des Browne, defence minister, who said on 25 January 2007:

"I do not believe it makes sense to say that nuclear weapons are inherently evil. In certain circumstances, they can play a positive role - as they have in the past. But clearly they have a power to do great harm. Are we prepared to tolerate a world in which countries which care about morality lay down their nuclear weapons, leaving others to threaten the rest of the world or hold it to ransom?"

Trident replacement is the answer to this question. 

Conventional Trident

The Pentagon proposed the Conventional Trident Modification program in 2006 to diversify its strategic options, as part of a broader long-term strategy to develop worldwide rapid strike capabilities, dubbed "Prompt Global Strike". This is not intended to replace nuclear deterrence, but to give commanders a first stike option against distant targets, even deeply buried and well protected, which would require to be destroyed in time-critical manner, ideally within half an hour from the start of a military operation. 

The US $503 million program would have converted existing Trident II missiles (presumably two missiles per submarine) into conventional weapons, by fitting them with modified Mk4 reentry vehicles equipped with GPS for navigation update and a reentry guidance and control (trajectory correction) segment to perform 10 m class impact accuracy. No explosive is said to be used since the reentry vehicle's mass and hypersonic (around Mach 25) impact velocity provide sufficient mechanical energy and "effect". The second conventional warhead version is a fragmentation version that would disperse thousands of tungsten rods which could obliterate an area of 3000 square feet (approximately 280 square meters). It offered the promise of accurate conventional strikes with little warning and flight time.

The primary drawback would have been establishing sufficient, recognized and trusted international warning systems so that other nuclear countries would not mistake it for a nuclear launch which could provoke a counterattack. For that reason among others, this project raised a substantial debate before US Congress for the FY07 Defense budget, but also internationally. 

Then Russian President Vladimir Putin, among others, warned that the project would increase the danger of accidental nuclear war. "The launch of such a missile could ... provoke a full-scale counterattack using strategic nuclear forces," Putin said in May 2006.

The Conventional Trident has never been officially dropped, but it is now seen as very unlikely to ever happen. A scaled down, 3000-miles conventional ballistic sub-launched missile was also touted for the role of global strike, and it reportedly had UK interest, but it also seems a programme unlikely to progress. 

Successor Submarine  

Pennant Number
Expected Builder
BAE Submarines Solutions, Barrow
BAE Submarines
BAE Submarines
B-04 (Requirement to be confirmed)
BAE Submarines

Status: Entered Concept Phase in May 2007, Initial Gate approval 18 May 2011.  Main Gate is officially expected 2015-16
In Service Date:  By 2028 expected date as of May 2011

The Successor Submarine or Future Submarine (FSM), more commonly known as “Trident Replacement” (rather incorrect term since, unless a dramatic change is made, the Trident II D5 missile itself will actually soldier on at least until 2040) is the programme aimed mainly at replacing the aging SSBN vessels of the Vanguard class, and, in a wider sense, targeted at enabling smooth continuation of the Continuous At Sea nuclear Deterrent (CASD) which the UK has maintained since 1969. 

On 4 December 2006 the then labour, Blair-guided government indicated a decision to maintain the UK's nuclear deterrent, building a class of 3 or 4 SSBN's to replace the Vanguards from 2004, and the MOD released the Defence White Paper "The Future of the United Kingdom’s Nuclear Deterrent".
In a  statement to Parliament Prime Minister Tony Blair told MPs it would be "unwise and dangerous" for the UK to give up its nuclear weapons. After extensive public debate, a Parliamentary vote on 14 March 2007 supported the replacement of Trident. and a final decision by the government to initiate the project was expected within months. The vote was supported by all conservative MPs as well.

In May 2007 the MOD's Defence Equipment and Support organisation (DE&S) stood up the Future Submarines (FSM) Integrated Project Team (IPT) to co-ordinate the project work. But Initial Gate approval did not take months, but years, to be approved: the milestone was finally reached on May 18 2011, after great controversity and endless political debate. The never-ending budget crisis did not help speeding things up.

From as far back as 2007, there’s been studies about the feasibility of a fleet of sole 3 vessels, instead of four. Three submarines  would seem to be a highly risky strategy - experience with  Resolution class SSBN's showed the significant fall off in operational availability that occurs as submarines age.  Three young submarines would allow a continuous deterrent patrol - but only as long as no accidents occurred while one was in a overhaul period.  However it seems very unlikely that this would still be possible as they reached 20+ years of age - at least  without significant technological breakthroughs, and/or an extraordinary level of redundancy in the design.  There is a very high probably that a three boat class designed and built to meet such “extremely demanding availability and serviceability requirement” would cost very little less than four boats built to more main stream standards - whilst having a much higher level of risk of gapping Britain's nuclear deterrent. In other words, the deterrent would seriously risk being not Continuous anymore, with periods occurring in which no boat was at the ready out at sea. The latest demonstration of this risk is very recent, as sea debris damaged HMS Vengeance’s propulsion, forcing the submarine to return in Faslane.  Considering that HMS Vigilant is docked in her 18-months long refit period and one of the other two submarines was just back from six months at sea on patrol, it is clear that without a fourth sub being available there would have been an inevitable gap in CASD.

While this risk is openly recognized, the pressure on the MOD to buy no more than three hulls is immensely high nonetheless, and only at Main Gate approval (2016, if further delays are avoided) it will finally be firmly decided if a fourth boat will be funded or not. The risk is very real that only 3 vessels will be built, and the risk accepted and justified with the argument that the ongoing collaboration with the US and the new collaboration with France will ensure that the UK is covered by the allies’s nuclear umbrellas even when its own is closed. However, it must also be considered that a fleet of three boats will be more hard worked than one of four, and this might take a toll on the vessels, making it hard to achieve the stated lifetime target of “25 years of service plus at least 5 more of possible extension”. USS Ohio class SSBNs are going to enjoy a longer life, but they are far less hard worked than the UK’s Vanguard: the Ohio fleet numbers 14 vessels, which means that each hull has been less stressed than any one of the 4 british SSBNs.

Since 2007, 900 million pounds have already been expended onto preliminary design work for the submarines, included collaboration with the US on the “Common Missile Compartment”, the submarine module that will contain the missile launcher tubes and that is meant to be common between the future Ohio replacement and Vanguard replacement. However, following the SDSR 2010, the CMC won’t be so common anymore: the british variant (if possible) will be sized down to 8 tubes, while the US are firm on their requirement of 12. The economic wisdom of such a change is to be questioned.

On 18 May 2011, the MOD released the document “The UnitedKingdom’s Future Nuclear Deterrent: The Submarine Initial Gate ParliamentaryReport” which contains a number of important informations on the progresses of the project.

First of all, it gives official confirmation that “a number of systems from the Astute class design have been incorporated within the design of the Successor submarine”, confirming, in part, everyone’s expectations. The Successor Submarine, however, will definitely not be an Astute with an “additional module with the launch tubes fitted” as someone had tried to advocate for. This is a wild simplification of a design work that is, really, monstrously complex and delicate, beating even the Shuttle’s design in terms of challenges. 

The report also confirms that the newest, most modern and safest PWR3 Pressurized Water Reactor has been chosen for the Successor submarine. The new reactor contains a very significant amount of American content, and is more advanced and has better safety features than the current PWR2, which fuels the Vanguards and, in its latest variant, the new Astute class SSNs. The PWR2 was the other option for the Successor Submarine.

The first PWR2 reactor was completed in 1985 with testing beginning in August 1987 at the Vulcan Naval Reactor Test Establishment.
The latest design of the PWR2 is the "Core H", which removes the need for refueling, allowing a submarine to avoid two reactor refits in its service life. HMS Vanguard was refitted with the new core during its Long Overhaul and Refuel Period LOP(R) (2002 – 2004), followed by HMS Victorious (2004-06) and then by Vigilant (which is currently in her LOP(R), to be completed by 2012). HMS Vengeance will be the last ship getting the refit, with the contract signed with Babcock in December 2010: she’ll enter the dock once Vigilant exits.
The Astute-class submarines have this full-life core installed from built, allowing for 25 years of service without need for refueling. As they were developed for SSBNs, the reactors are considerably larger than those of current British SSNs. The diameter of Astute class hulls has therefore been increased to accommodate the PWR2, which was a big driver in the increase of sizes of the Astute compared to old Trafalgars.


Rear Admiral Simon Lister, the MoD's Director Submarines, said: "While the Pressurised Water Reactor used in our existing submarines is a robust, highly controlled system that meets our stringent safety standards, the new Pressurised Water Reactor 3 will deliver further improvements such as ease of operation and lower costs over its extended life."

The MOD’s report states that the PWR3 reactor is “around 50 million per boat more expensive to buy and operate over a 25 year life, but would be cheaper if we were to operate them for longer because of PWR3’s longer life.” Since a longer than expected life is almost certain, it makes sense. (The Vanguards themselves will service for at least 5 more years than planned)

About the Common Missile Compartment, the report notes that commonality with the US design (already at a quite advanced phase of development) will be retained due to its benefit on economies of scale in the project, but that “work is ongoing with the US to look at how best to include our requirement for [just] eight operational missiles into this design”. In other words, if possible, the CMC for the Royal Navy will be literally cut short. If not, the tubes might not be kitted for launch, or anyway downgraded as much as economically advantageous. The CMC design includes an increased diameter of the launch tubes from 2.21m (current) to 3.04m, allowing easier future use of the tubes for other roles (from multiple Tomahawk canister-launchers to drones to special forces gear) and integration of replacement missiles that, in the long life of the new submarines, could grow larger than current D5.

Four converted Ohio class SSGNs have already replaced nuclear missiles with American special forces and land attack missiles, and the Virginia Class Block III fast attack submarine replaces 12 vertical-launch cruise missile tubes with 2 Common Weapon Launcher “six-shooters” derived from the SSGNs’ converted missile tubes. It provides an example of what could happen with some of the tubes of the future SSBN. The size of those CWLs will allow these submarines to launch cruise missiles, UAVs, UUVs, and more from these same tubes. One SSGN can carry up to 154 Tomahawk missiles, 60 members (up to 102) of the SEALs or other forces and up to two Swimmer Delivery Systems SDV in dry deck shelters. One of the SSGNs, USS Florida, delivered, alone, nearly 60% of the over 112 Tomahawk missiles fired at Libya on the first night of Operation Odyssey Dawn. 
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.

Before main gate, the design of the submarine is expected to be at least 70% mature. By 2016 there will also be initial Long Lead Items orders, that the report presents as:

-          380 million for Boat 1, split between propulsion, main boat systems and steel
-          145 million for Boat 2, also for propulsion systems
-          6 millions for Boat 3, also for propulsion systems

There won’t be any Long Lead order for items related to the Boat 4 before 2016, as the requirement for the fourth hull is not yet firm. This adds to 900 million (at outturn prices) in design and development work done from 2007 up to today. By 2016, the Submarine Industry will have to expand facilities and workforce for the work ramping up on the new, much larger class of vessels, and 70% of the design will have to be finished, including the addition of “new or emerging technology planned including communications, tactical weapon systems, batteries and structural materies.” These will have to be included in the design “at an acceptable level of risk”. Financial constraints are keeping ambitions down, so we aren’t looking at a quantum leap progress in submarine technology compared to the Astute, but several improvements will still be pursued.

In total, by 2016 the Successor Submarine will have been given 3.9 billion pounds in funding, or 15% of the estimated total programme value (for a four-boats fleet). The press reports on the Successor Submarine’s price jumping from 20 billions to 25 “because of the PWR3 reactor choice” are grossly incorrect. Estimates at 2006/07 prices for the Trident replacement were for a total cost ranging from 15 to 20 billion, with 11 to 14 due to the four submarines themselves. The 25 billions figure is due mostly to MOD calculations done at Outturn prices: when adjusted for inflation, the 2006 figure grows to 25. The cost of the four vessels is still expected to range between 11 and 14 billion in 2006 money terms, including programme risks.

2 to 3 billions is the cost estimate for the upgrade/replacement of both warheads and infrastructure, but both of these two expenditure voices are at least 10 years away in time, as the SDSR decided that there is scope to delay both elements. The Successor Submarine design will be such to make as few and little modifications as possible needed to Faslane’s infrastructure, while the warhead is now expected to be operative up to 2030, with only minor mainteinance due at around 2020. The Trident missile itself is not expected to be replaced anytime before 2040. As part of infrastructure, the Atomic Weapons Establishment Aldermaston has received and will receive further improvements, but as part of a drive to keep costs down, a Joint test facility will now be built together with France, allowing significant savings to be achieved.  

Savings in the nuclear deterrent, identified by the SDSR and due to be implemented by 2020 and continue on the Successor Submarine, are a further reduction in the number of deployed warheads, from 48 to 40, mounted on 8 missiles. Each Trident is thus fitted with just 5 warheads, plus (possibly) a number of Decoys. The number of available, ready-to-deploy warheads is to go down from around 160 today to no more than 120 by 2020, with an overall reduction in the stockpile from 225 to no more than 180. 

UPDATES and progress: