Scottish Affairs CommitteeWritten evidence from Francis Tusa, Editor, Defence Analysis


1. This memorandum is provided to support testimony provided to the Scottish Affairs Committee of the House of Commons on the topic of the impact of the prospect of Scottish independence on defence.

2. More specifically, it is to provide some extra depth to the subject of the relocation of the nuclear deterrent force in the event of independence being followed by electoral victory by the Scottish National Party, whose manifesto has stated that an independent Scotland would be “nuclear free”.

The Issue

3. When the topic of the deterrent, its current basing at Faslane and associated facilities, and what might happen in the event of independence and an SNP electoral victory is raised, a number of reactions are stated immediately, almost as matters of faith:

(a)“The movement of the deterrent would be immensely difficult to consider, and would take decades to achieve”;

(b)“It would cost many billions of pounds to replicate the facilities that are at present in the Faslane/Coulport area, and it would take well over a decade to do so”; and

(c)“There are no realistic options for the deterrent in the event of a non-nuclear Scotland”.

4. These views are, and have been treated as a form of gospel truth, with heavy backing from the Royal Navy, but also from other areas of the defence world.

5. There are some signs that these dogmas have also taken on political overtones, as it is widely believed that an independent Scotland would have the rump UK over a barrel in the event of independence, with the ability to bargain, to Scotland’s advantage, on what happened to the deterrent.

6. However, simple examination of the subject suggests that the issue is not as complex as might have been thought, and that the dogma has muddled clear thinking.

7. What is strange is that one of the major source of the type of views expressed in point 3 is the Royal Navy. This has given the dogma a degree of momentum which is not backed up by more rational thinking.

The Resolution

8. A major source of the belief that the deterrent relocation is an insoluble problem results from the fact that the issue is looked at in its entirety, and on such a basis, things can look incredibly complicated and difficult to resolve.

9. But by breaking the whole into its constituent parts, it is far easier to see how the deterrent re-location problem can be tackled, and in easy steps.

Deterrent Segment

Current Location

Future Location


Submarine basing

HMNB Faslane

HMNB Devonport

A fully licensed nuclear submarine base. Homeport of the nuclear fleet since the 1960s. 16+ nuclear berths available, compared to 10 at HMNB Clyde.

Submarine maintenance

HMNB Devonport

HMNB Devonport

All the facilities for the current and future SSN/SSBN fleet support will be based at HMNB Devonport.

Ballistic missile storage

King’s Bay, Georgia, USA

King’s Bay, Georgia, USA

No evidence of any plans to change this bilateral arrangement.

Warhead build/maintenance

AWE Aldermaston

AWE Aldermaston

No evidence of any plans to change this arrangement.

Warhead storage

RNAD Coulport

?AWE Aldermaston? Satellite facility at new missile loading facility.

The issue is not about replicating RNAD Coulport—see below.

Missile Mating

RNAD Coulport


The one element of the current cycle for which there is not an automatic facility available elsewhere in the UK. However, as the Explosive Handling Jetty is floating, and was towed into place, there would seem to be little reason why it couldn’t be

10. The analysis shows that for four out of the six stages of the SSBN support/operational cycle, there is either an easy, readily available alternative, or there would be no change in the status in the event of Scottish independence.

11. In one of the six stages, there is an existing option—the storage of nuclear warheads at AWE Aldermaston—one that could readily be changed in status from a maintenance role to a storage one.

12. In only one state of the cycle—missile/warhead mating—is serious decision making required. But as seen by the fact that the current piece of equipment is floating, and thus re-locatable, this is not as insolvable a problem was might be considered.

The “Coulport Question”

One of the biggest misconceptions with the debate—or lack of it—about the issue of where the deterrent would go to, is that people talk about “replacing Coulport”. This has muddied the water, as there is no direct requirement to replace Coulport.

Coulport was designed, scaled, and built to support the original Trident deterrent systems. This saw a Vanguard-class SSBN able to carry a maximum of 192 warheads. In theory, the 58 Trident missiles that the UK has access to as part of a shared pool of weapons with the US Navy can carry in the original design, some 700 warheads.

However, in the 1998 Strategic Defence Review it was stated that:

“The single Trident submarine on deterrent patrol at any time will carry 48 warheads”;


“We will maintain a stockpile of fewer than 200 operationally available warheads”.

The Strategic Defence and Security Review announced that the current Vanguard-class SSBNs would carry a maximum of eight Trident missiles, and around 40 warheads.

The intention is that the entire stock of nuclear weapons will be certainly no more than 160 by the 2020s. If there is to be one deterrent SSBN on patrol at any one time with eight missiles, with four to six warheads each (the issue of decoys brings the mathematics into a different area!), then this could see the maximum requirement for warheads down to around 100. It is difficult to imagine the Successor-class handling:

(a)More missiles than the eight that the current Vanguard-class SSBNs carry; and

(b)More warheads than the current Vanguard-class SSBNs carry.

The point here is a simple one: Coulport, as a storage facility, was scaled to stock and handle hundreds of Trident warheads, but the current and future requirements are for far smaller stocks. The current licensed facilities could readily store and handle such numbers, and could do so almost immediately.

As a result, there is no need to replace, in all aspects, least of all size, Coulport as a facility. This means that the cost of Coulport wouldn’t have to be replicated in the same magnitude. This would make the “replacement” of Coulport substantially easier.

In practice, most warheads could be stored at the current maintenance/support facilities at AWE Aldermaston/Burghfield, with a small satellite facility required for the process of mating to the missiles.


People, especially the Royal Navy, have become “comfortable” with the current situation regarding nuclear submarine/warhead basing and operations—it is easy to show that of the options available, it was at the time, the best selection.

However, the factors that made Faslane (and RNAD Coulport) the optimal solution in the 1960s-70s would be irrelevant if there was a vote in favour for Scottish independence, followed by a demand for the withdrawal of deterrent systems from Scotland—the suitability or otherwise of Faslane would no longer be open for discussion.

But substantial elements of the deterrent—arguably, most of them—could be moved with little trouble to existing facilities in the rump UK. The one element that requires planning would be for the missile/warhead mating facility, but as this is a floating edifice, it could be moved to another location.

It is true that the resulting operational construct might be less convenient than the current one—but it would be entirely workable.



This paper intends to lay out, as far as is possible, the difference in the size of the current Royal Navy ballistic submarine (SSBN) base, and those of conventional submarine (SSK) operators in other European countries. It also intends to show the size of the industrial workforce used to design and build conventional submarines in European shipyards.

Current Situation

The submarine facilities at HMNB Faslane employ some 1,000–1,100 people, excluding civilian workforce employed by Babcock as part of the contract to manage the base, and also to support the submarines. RNAD Coulport employs an extra 600–700 staff.

Differences between SSBNs and SSKs

The workforce to support SSBNs/SSNs is substantially larger than that required to support SSKs. The principle reason for this is the safety aspect of nuclear reactors, but the complexity of extra systems carried by larger SSNs/SSBNs also adds to the total.

The crew size for nuclear submarines also tends to be higher, typically 80–95 for SSNs, 110–130 for SSBNs, as opposed to 30–40 for many SSKs. As SSBNs, too, tend to operate on a “Gold-Blue” double crew systems, to allow for longer, and more manageable deployments, the overall size of the crew required for a fleet of four SSBNs will be six plus complete crews.

European SSK Bases

It has to be noted that most European navies operate their submarines from the same bases as surface ships, so some jobs are common across the piece. This is true for Germany, Netherlands, Sweden, and Norway. Some figures for naval base size are:

Sweden: Karlskrona naval base

Submarine support element: c300

1,250 personnel (1,000 military, 250 civilian)

Netherlands: Den Helder naval base

Submariner support element: 350–400

11–1,350 personnel

Although it is difficult to get precise triangulation, some of the SSK support services of southern European navies (Spain, Italy, Greece) seem to be larger at 600+ personnel or more.

Conventional Submarine Construction

There are three to four shipyards in Europe (Germany, Sweden, France, and potentially Spain) where there are the complete design and construction skills to undertake all aspects of conventional submarine building. There are then several other yards (Italy, Norway, Greece, Turkey) which have the capabilities to build-to-print conventional submarines.

The Thyssen Krupp Marine Systems yards in Kiel employ around 1,800 personnel, although there is some non-submarine activity here. It should also be pointed out that TKMS is a world leader in submarine design and construction, so has a large customer base to support from Kiel, which means that there is a larger workforce than would be the case in other countries.

The Kockums yard, also owned by TKMS, but based in Sweden, employs directly 3–400 people in support of Swedish national programmes, and the small export business that requires on-going support services.

The Navantia yard at Cartagena employed about 400–600 at the peak of the S-80 build programme, but is down at 2–300.

Conclusion: The smallest sensible size of a conventional submarine flotilla (on the basis of operation and affordability) is four boats. For manpower, there would be 20–25% of the crew required to man these as opposed to a 4 boat SSBN flotilla.

The support of a four boat SSK group would be 40% of that required today for four nuclear SSBNs at a maximum of 400 personnel.

The workforce required to build, and then provide longer term in-service support for a four boat SSK fleet in Scotland would be a peak of 5–600 in the middle of construction, falling to 100–150 for support.

14 August 2012

Prepared 22nd January 2013