A good alternative to SSBNs...?

A new proposal has been put forwards as an alternative to the Successor SSBN programme which is due to produce 3 to 4 new submarines as replacement for the current Vanguard class, with entry in service beginning in 2028. The effort is known to the general public as "Trident replacement", but it is a very misleading name for the project, as what needs replacement is the submarine, not the Trident missile.


Successor - a quick summary 

The same Trident 2 D5 missiles currently in service will continue to be used at least out to 2042, so it is most definitely not a matter of replacing Trident. The warheads are also good out to 2032 at least, as they are subject to a life extension programme which brings them to MK4A standard. A decision on an eventual replacement is not expected to be required before the late 2030s, and it is to be assumed that, if possible at all, efforts to eventually replace the warhead and the Trident missiles themselves will be coordinated in the 2040s.

The four Vanguard submarines, on the other hand, can no longer be life extended safely and effectively. Their useful life has already been stretched and the first of the class is now due to soldier on until 2028, but it is assessed that extending further is not desirable.
Main Gate for the Successor programme, which will finally place a formal contract in place for the acquisition of 3 or four new generation submarines, is planned for early 2016, but design activities and procurement of key long lead items (included the new PWR3 reactor core and the special steel for the hulls) are already underway, with a spend ceiling of 3.3 billion pounds by 2016. As of december 2014, 1243 million pounds have already been committed. Notably, 206 million are for the upgrading and restructuring of the Barrow shipyard facilities which are key to the UK's ability to build submarines, and the usefulness of this investment goes beyond the Successor itself.
The new PWR3 reactor, more advanced than the current PWR2, builds on very significant amounts of technology shared by the United States. Its features include a far longer unrefueled service life (the american equivalent reactor project for their own new SSBNs aims for a 40 years unrefueled service life, versus a target of 25 years for the PWR2) in order to minimize in-service costs during the life of the vessel; and enhanced safety.

In October 2014, a notable long lead contract has been placed, with a 59 million dollar contract signed with General Dynamics Electric Boat for the production of the 12 Trident launch tubes for the first SSBN. The US Department of Defense, in the same contract, has ordered a first batch of 5 tubes for its own SSBN.
This unprecedented level of collaboration is part of the Common Missile Compartment initiative. The CMC is being designed in 4-tube modules which are then integrated into the submarine at build: 3 sections will form the british CMC compartment (12 tubes in total, down from 16 in the current Vanguard class), while the US SSBN will have four sections (16 tubes, down from 24 in the current Ohio class).
The first 4-tubes module should be assembled beginning in August 2016; the first launch tube is expected to be delivered for installation in the module during November the same year. The 1st Quad Pack module should be completed in April 2018, with deliveries of all the 17 tubes currently on order completed by November 2017.
Initially, it had been thought to "future proof" the tubes by producing them with a 97 inches diameter, but this idea was shelved to save money, and the diameter will stay at 87 inches: whatever missile eventually replaces Trident 2 D5 will have to share the same diameter.

Other design features of the british SSBNs aren't yet known in detail. A CGI image released by the MOD suggests that an X configuration for stern control surfaces is being planned, like in the US for the SSBN(X). Despite having less launch tubes, the new SSBN is expected to be as large as the Vanguard, and possibly slightly heavier. Growth is being contained, however, with the aim of reducing to a minimum the need for infrastructure changes in Faslane and Coulport. What is good for the Vanguards must be good for the Successor as well.
In a similarly pragmatic decision, according to 2013 data reports, the Successor will draw largely from the Astute class SSN, sharing the same sonar and combat system, the same torpedo tubes arrangement and the same mast sensors. A Common External Communications System is also being acquired, which will use the same launcher and Comms buoys for both Astute and Successor.
It has been suggested that much of the crew will be able to seamlessly transition from SSBN to Astute SSN at any time, due to the great commonality.

As part of budget cuts, the SDSR 2010 has mandated a new round of reductions in the number of warheads and operational, embarked missiles. Currently, the Vanguard class SSBNs deploy at sea with no more than 8 Trident missiles equipped, in total, with 40 warheads. Each Trident missile can be fitted with up to 12 warheads, so the current totals are far, far reduced from the original 16 missile / 192 warheads load envisaged for the Vanguard. The number of operational, availlable warheads has also been reduced, to a maximum of 120 (was 160 before the SDSR), our of a total of 160 (was 225 before SDSR). 

The Trident 2 D5 missiles are exactly the same used by the US Navy. Indeed, the UK has access to up to 58 such missiles (not clear if the few expended in trials over the years have been replaced or not), which are maintained as part of the US Navy's total. To safeguard the independence of employment of the deterrent, the nuclear payload is british.

For comparison purposes, France maintains a total of 300 nuclear warheads; three sets of 16 submarine-launched ballistic missiles for it's four SSBNs and 54 air-launched ASMP-A missiles.

Even with all these measures to contain costs and achieve maximum efficiency, the Successor programme remains expensive. The December 2014 update to Parliament assures that the programme for now promises to respect the original 11 to 14 billion pounds pricetag set in 2006. Adjusted for inflation, that means 14.21 to 18.09 billion pounds in 2014 money (Bank of England calculation). We will assume a price range between 15 and 20 billion pounds for four submarines as a measure of prudence. A price which, of course, many charge of being still too optimistic.


Centre Forum steps in

Toby Fenwick, former Treasury and DfiD civil servant as well as RAF Intelligence reservist between 1995 and 2009, has written a paper, published a few days ago by Centre Forum, to argue for the abandonement of the plan for a continuation of Trident and a cancellation of the SSBNs, in favor of an air-dropped nuclear deterrent which would cost less and deliver much greater conventional capabilities in exchange for a diminished nuclear arsenal.

The list of recommendations made by the document are the following:

It is evident at first read that the nuclear arsenal resulting would be much weaker than the currently planned one, but at the same time it is evident that the proposal would bring much enhanced conventional military capability in the air and at sea.

The proposal is to adopt the free-fall B61 nuclear bomb, which is deployed in Europe as part of the NATO Nuclear Sharing deterrence concept. The B61s are tactical, free fall bombs meant for supersonic carriage, and a part of the arsenal is made available to allies for employment on their own aircraft: for example, Germany and Italy have Tornado IDS squadrons with a nuclear strike role, and the F-16 is also used. Other B61s forward stored in Europe are available for use by USAFE aircraft.

The B61 exists in several different variants, but the US has launched a costly refurbishment programme which will leave only one type of weapon in operation, the B61-12. This is obtained employing the B61-4 variable yeld warhead and introducing a new tail kit which, while not adding actual precision guidance, dramatically improves accuracy on the target and gives a modest "stand-off" range in a high speed toss towards the target. Some 480 bombs in total will be refurbished, at a cost estimated between 10 and 12 billion dollars.
The B61-12 is to be integrated for internal carriage on the F-35A.

A B61-12 being tested in the wind tunnel

The proposal is to seek integration of the B61-12 on the F-35C as well, which is physically feasible since the weapon bays have the same size (not so with the shorter bays of the F-35B), so that RAF and Royal Navy can procure 138 F-35C, to be used as dual capable aircraft.

The document also contains indications on the expected price of the proposal, which to be workable requires considerable investment in conventional capabilities surrounding and enabling the deterrent.

It is to be appreciated that the document keeps track of the need for aircraft carrier embarkation and delivery in order to make the deterrent capable to strike back against any enemy, and that it consequently makes provvisions for enhancing the surface fleet to provide more appropriate escort, adding more Type 26 frigates and Hawkeye radar aircraft.

It is also good to see that the author did not ignore the need to provide Barrow with more SSNs to buy in order to keep the yard active and it's key skills alive: one of the roles of the Successor programme is also to bridge the gap between the construction of the Astutes and the future project for their replacement. Years and years of inactivity destroy the workforce and squander the precious skills required for building submarines. It is a lesson re-learned at the cost of much money and great delays to the Astute project: after years of inactivity, the design team ended up having to ask the americans for help in order to finalize the Astute's design. So, if SSBNs aren't built, SSNs must take their place, or the cost could well be the loss of the nation's ability to build any at a later date.

The passage to catapults for the carriers brings an evident boost to capability and is required since only the F-35C can hope to carry the B61-12 internally. The purchase of Hawkeye is key to giving the air wing  and the carrier itself the survivability they need.


The problem

A nuclear deterrent based on the B61-12 would be much less capable than Trident, this is definite. The key issue is not the power of the warhead, but the certainty that an enemy anywhere in the world can be reliably hit. Any possible existential enemy of the UK must be keenly aware that there is a credible deterrent which is unquestionably able to strike back and make him pay a price which cannot be possibly accepted.

The reach of the B61-12 is the main problem. The document says that F-35C launched from UK bases could strike 2500 nautical miles away with Voyager tankers support, and goes some way in explaining how, using british bases overseas and the carrier's air wing the reach can be made sufficient to strike virtually anywhere. There are obvious difficulties with such a scenario, and there is pretty much the admission that any delivery flight would be more or less a suicide.
Then again, if it ever came to flying a real nuclear bombing mission, coming back to base might not be an option anyway.
The key, as always, is not doing it for real, but showing in a convincing way that it could and would be done. The deterrent must be credible in the sense that an enemy must be convinced that cornering the UK would result in a devastating nuclear revenge which would make any conquest ultimately futile. The deterrent must represent an implied, unacceptable price to pay that forces an enemy to drop the idea of acting in the first place. If we get to the actual use of nuclear weapons, it means the deterrent has failed, even if it later succeeds in delivering nukes on enemy towns.

A number of B61-12s hitting major enemy towns and installations would represent a cost too high to be accepted, by anyone and in any circumstance, even if the target hit wasn't the enemy capital itself. On this i can agree.
Where the credibility gets shaky is in the delivery. A Voyager tanker can trail 4 fighter jets for 2800 miles in a transfer flight, but an actual stike mission, especially if a return to base is at least envisaged, is a whole different matter. Even bringing all 14 tankers in service (instead of just 8 + 1 transport only and 5 tankers "on demand" at 90 days notice) and fitting them with booms and receptacles so they can juggle fuel between themselves and work cooperatively, it remains dubious that it would be possible to trail a real strike package over the great distances likely to be involved. Particularly because, in order to deliver the strike with gravity-fall bombs with a stand-off reach of 40 kilometers in the very, very best case, you need a large attack squadron, knowing that many aircraft are likely not to make it to the target, even with the F-35's stealth.

Would it ever be possible to make this construct credible enough to serve its purpose? 

At one point the document talks about a snap launch of 72 aircraft in the space of little more than 2 minutes in answer to a detected nuclear attack. But it is clear to me that there could never be 72 aircraft at readiness, never mind at a 2 minutes readiness, not even if there was a significant "warning" period of worsening international situation beforehand. And moreover there would never be enough tankers to trail them to a distant target anyway.
Besides, if the vast majority of the improved tanker fleet and of the larger fighter jet fleet are tied into nuclear readiness, the potential advantage they bring in terms of conventional capabilities is lost because they aren't available for other missions. If the end result is having less tankers and less aircraft readily available for conventional operations, the whole idea is self-defeating.


Costs

The idea falls apart further when costing is examined with greater attention. The procurement of 100 "anglicized" B61-12 weapons might be simply impossible, at least in the terms envisaged in the document. The B61-12 is built by refurbishing existing bombs, and there is only a finite number of them.
It would of course be possible to purchase the new Tail Kit, which is a new production element, but all the rest, and not just the warhead, would likely have to be new. This calls into question the timings and costs estimated.

Moreover, the document assumes a 30% cost increase for the Successor programme based on the Astute's earlier mentioned troublesome birth. The assumption that costs will grow is admittedly pretty realistic, unfortunately, but i cannot help but question the method. It seems a bit unfair to inflate the cost by 30% right away, and base the comparison on this figure. A 15 to 20 billion programme cost is assumed in the document and then brought up to a 24.8 - 33.1 billion affair. Sincerely, i find this skews the discussion. Expecting cost growth and doubting of estimates is one thing, but this seems way excessive.

Again, the document assumes that building 5 more Astute SSNs will cost 5 billion pounds or less, while also enabling the adoption of the PWR3 reactor, or at least of part of its technological improvements. It seems to me like a shot in the dark. You can't assume unchanged or indeed diminished pricetags for an SSN if you also assume that you will change its very heart, the nuclear reactor. It would seem only fair and prudent to me to assume that trying to take in PWR3 tech would require quite some design work, and consequently costs.

The purchase of 138 F-35C is also described as a saving of over one billion. But this is sadly unjustified, simply because the UK does not have a budget for 138 F-35B as of now. Not even close. So, even assuming the F-35C as effectively cheaper to purchase and to operate, several billion pounds are missing from the count.

The purchase of 8 P-8 Poseidon maritime patrol aircraft for 700 million pounds also look like a miracle to me, considering that Australia is going to pay 3.6 billion USD (around 4 billion AUSD) for the same amount of the same aircraft (and the supporting elements and infrastructure, but it is not like you can leave those out of the picture). It is a mistake i've already seen in other occasions: you can't just take the unitary price tag from a US multi-year mega contract and expect your purchase to come at that same price. What about spare parts, training, support, infrastructure, and everything else?
I wait to see how much Japan will pay for the 4 E-2D Hawkeye it has ordered, but i sincerely believe 900 million pounds might well prove insufficient. 

Modifying the Voyager tankers with booms is something that could indeed be done in a few months per airframe, and probably with a modest investment. But adding in the receptacle might not be as simple, and the cost suggested, i fear, is likely again overoptimistic.

The C-2 Greyhound is no longer in production, and the surviving examples are high in demand in the US Navy. Moreover, even if some could be acquired, the US Navy has estimated that their useful life will expire by 2028. A refurbishment programme which would replace the wings, the engines and the avionics and make them more common to the E-2D has been proposed, but the US Navy has not been convinced and has instead decided to procure 44 MV-22 Osprey for the role.
The document also suggests converting the Greyhound to serve also as tankers to extend the range of the F-35C embarked squadrons, but this has never been done before. I would suggest that the US Navy would have already done it, if it was that straightforward.
The MV-22 will have a tanker kit by 2017, and the navy variant, HV-22, is likely to be fitted with external, conformal fuel tanks which would also increase available fuel to give away... but this is another story, and would have a whole different cost from what the document proposes with the C-2.

I think there is too much optimism regarding infrastructure as well, since counting on old 1969-era structures dating back to the V force seems a bit risky to me, but i'm not able to make an estimate myself.
What looks clear to me is that there is no real consideration given to the greater manpower and annual budgets which would be required by having far more squadrons of jets than planned, more tankers in continous service, more SSNs and more frigates. Even assuming that current SSBN-related personnel can cover completely or almost completely the crewing needs of 5 new SSNs, i think a lot is missing from the picture.


Conclusion

The boost to the conventional forces that an air deterrent would bring is certainly tempting. If the costing was realistic and actually feasible, i would sincerely be tempted to support a proposal like this. The credibility of the deterrent would be menaced, but i think it could be made to stay at a reasonable and thus acceptable level: i would like to think, after all, that no country in the world would consider "a few nuked cities" as an acceptable price to pay in any scenario. My way of thinking suggests to me that the demonstrated ability to deliver nuclear strikes at range, even with difficulties and limitations (it would never be the same as a 10.000 miles Trident missile launched literally out of the blue, where you can't touch it beforehand) would be enough, if balanced by such a healthy increase of conventional firepower as a byproduct.

The problem is that to stay credible, the air deterrent would tie down almost entirely those additional F-35C squadrons and, critically, the Voyager tankers. To deploy them on conventional operations will dramatically reduce the capability of the deterrent, and to keep them at nuclear QRA means badly hurting conventional capabilities. 
And moreover, the cost estimates seem to be wide off the mark, making the whole thing unachievable in the shape and budget proposed.

In the end, the SSBN once more remains as the most cost-effective and most credible deterrent solution.