The Nuclear Information Service, General (rtd) Sir Hugh Beach and others have made a strong arguments against the retention and renewal of the ballistic missile system in the UK, colloquially known and “Trident” (after the US Submarine Launched Ballistic Missile (SLBM)). Their arguments can be found in this evidence paper.
Given the extensive arguments presented, I turn to cover another area not exactly mentioned. That is, the burden of keeping Continuous at Sea Deterrent or CASD. As the name implies, 24/7/365, there is at least one UK Vanguard Class SSBN patrolling somewhere in the ocean. A second is undergoing training (and ready to relieve the patrol boat when it returns), a third is under maintenance while a fourth is in reserve (may also be readying to relieve the patrol boat). This is taken from page 7 of this research paper.
Such tight non-stop patrols means that Royal Navy submariners are tasked forever to fixed on the deadly duty of ‘deterring’ others from other nations from launching nuclear/chemical/biological weapons, well mainly nuclear, against the UK. Each V-Boat is crewed by 135 sailors. And each V-Boat, unlike SSNs, has two crews to ensure unbreakable CASD–known as Port and Starboard crews. A look at an old Royal Navy Bridge Card for example, shows that at least Vanguard and Vengeance have two crews–I’m sure all four boats have. This means that 135×4=540 sailors are on nuclear deterrence. Given the need to deploy, train, maintain (and crews train while there’s maintenance) and be on reserve, it is highly unlikely the 540 sailors can be used for other tasks.
This means that this lot of ‘special’ officers and ratings are kept forever from executing conventional duties. In the ever pressing need for the Royal Navy to project British global power, 540 sailors aren’t able to contribute to normal patrols or respond to emerging crisis. This number of sailors is even more, considering that there are others in the operational management of the whole nuclear deterrent–for example, staff in Faslane, the MOD and elsewhere. Furthermore, in the latest era of cuts, this means that well, these 540 plus sailors and troops are sparred from retrenchment. That’s nice, but it also means that while you retrench other sailors, the 540 would be looked on jealously–“hey, we should have volunteered to be V-boat sailors, then we wouldn’t have been sacked!” Taking it from another view, the MOD are retaining 540 plus sailors that cannot perform duties such as daily patrols, Fleet Ready Escort or even homeland resilience–helping with the floods.
Another argument is that the V-Boats do not just carry deadly Trident D5 SLBMs. They also have four torpedo tubes for firing Spearfish Torpedoes. With four tubes, this means that there are at least eight (or ten) Spearfish Torpedoes per boat. So at least 32 Spearfishes are with the V-Boats. This is alot and it means that the Navy cannot use 30 plus torpedoes. V-Boats are not attack submarines can cannot act like one. Even if one wants to (take away the SLBMs), V-Boats are not of the design to conduct SSN-like missions. And again, in the era of cuts and calls for making the RN stronger, well you have torpedoes in untouchable subs which you cannot withdraw them from.
Back to the personnel angle, with four boats, V-Boats or its successor, this means feeding and paying around 540 sailors (if by any luck the next class will require less manpower). Again, hundreds of foodstuff needed to feed sailors who frankly, do nothing except know they have doomsday devices that can be launched. The pay may be better than other Royal Navy sailors, but again, with budgets tight, it’s a unsaid ringfencing.
Thus, personnel torpedoes, food and payment. And you still wish to have four nuclear-powered submarines with weapons that should never be used??