Current Nuclear Weapons Development

I am wondering what happens if war does break out who has the right to give the order to launch the nuclear missiles from Royal Navy SSBNs?
 
The RN. The U.S. exerts no control over them, though when not on a RN submarine, I believe they are all stored in the states. I believe the U.S. does supply ballistic parameters to the RN as well.
 
Sferrin said:
I would think getting your own SLBMs would be high on the list. Right now, as I understand it, the US and UK draw D-5s from a common pool? While that is convenient for both parties, if you want to go your own way, I'd think you'd want to cut that leash.
Click to expand...
Yes, it would take buying a % of the missile pool off the US or developing your own not-Tridents.


FighterJock said:
I am wondering what happens if war does break out who has the right to give the order to launch the nuclear missiles from Royal Navy SSBNs?
Click to expand...
The UK has that authority. Not the US.

Warheads are UK, missiles are US-made.
 
Then having our own SSBNs armed with our own ballistic missiles would remove that problem of having them stored in the US and not the UK.
 
Odd I thought we stored some while boats underwent maintenance?
 
But I take it that the rest are stored in the US, that would make it particularly difficult if a war situation ever broke out for real. How would we get all the rest of the missiles into the submarines in time to retaliate, we should build more storage facilities in the UK so that we could store them here instead.
 
Agreed that we seem to have the absolute minimum storage for Trident available. Not ideal but obviously driven by minimising the costs to the greatest extent.

In these times, transit across the Atlantic is a weakness irrespective of US perfidy over access. Which hasn't yet happened.....at least to our knowledge.

Arguably then increases in storage is a logical and moderate cost option.
Because if all else fails, a submarine can be towed to the loading facility and towed out to launch it's missiles. As some kind of last ditch effort.

All very worrying stuff.
 
FighterJock said:
But I take it that the rest are stored in the US, that would make it particularly difficult if a war situation ever broke out for real. How would we get all the rest of the missiles into the submarines in time to retaliate, we should build more storage facilities in the UK so that we could store them here instead.
Click to expand...
?

Trident subs carry their full missile load basically at all times.

The UK has storage space for one sub's worth when it's going into drydock for an extended period. 4 warheads per missile times 16 missiles per sub times 4 subs = 256 UK warheads ready to fly
 
Thanks Scott Kenny, I did not know that the UK Trident subs carried their full load of missiles at all times, makes sense really.
 
JTR said:
Storable liquids did not have any significant or detectable prep time. As long as the guidance systems were kept spun up, then the only limiting factor was the time to open the silo door and go through the launch sequence, which was extremely short for both storable liquids and solid propellants.

For example, the (storable liquids) Titan II could be hot launched from within the silo in under 60 seconds (some sources say under 58 seconds).

Similarly, the (solid propellant) Minuteman III can also be hot launched from within its silo in under 60 seconds.

The Soviets developed the technique of "ampulization" of their storable liquids ICBMs to allow leaving them fueled for extended periods of time (initially 5 years, then 10 years, and eventually as high as 15 years). This was deployed starting with the second generation of Soviet ICBMs, which were deployed in the 1965–1973 period.

There was no "couple of hours" warning once solids and ampulized storable liquids became mainstream, which happened quite rapidly.

For the Soviets, their ampulized storable liquid missiles were every bit as good as a solid propellant missile when it came to missile launch times.
Click to expand...

As far as I'm aware, "storable" is only relative to cryogenic liquid propellants, as a lot of the oxidizers had a tendency to oxidize the missile itself if left alone for too long. I didn't see this soon enough, but I had some documents open last week that claimed three weeks was the maximum time some of these things could be stored and after that the missile had to be defuelled and inspected for damage caused by the oxidizer (RFNA is nasty, high-test Hydrogen Peroxide is not all that much better; and some of the fuels used were just as bad).

The main problem with warning was location. The previous TBMs used by the Soviets had short enough ranges that they had to be on the border to hit strategic targets like the Atlantic ports, and their bases were "scoutable" - you could see if the roadmobile TELs were there or not from aircraft on the right side of the border. "Oh shit all their bases are empty" is a pretty decent warning.

SS-20/Pioneer could hit Rotterdam or Brest from the far side of the Caucasus. If employed in the same locations that the old missiles were they could hit Keflavik. And when NATO tried to negotiate them away, Dmitry Ustinov went "you don't have anything worth trading my missiles away for." Which is why Pershing II and GLCM were developed, effectively - to be something scary enough that the Soviets would be willing to trade away SS-20. (Russian wikipedia on the INF treaty goes into much greater depth about the historical situation and previous attempts at treaties than the English one, and chrome's translator makes it pretty readable).
 
Scott Kenny said:
?

Trident subs carry their full missile load basically at all times.

The UK has storage space for one sub's worth when it's going into drydock for an extended period. 4 warheads per missile times 16 missiles per sub times 4 subs = 256 UK warheads ready to fly
Click to expand...
There are only 48 missiles as far as I'm aware.
 
Winchester said:
As far as I'm aware, "storable" is only relative to cryogenic liquid propellants, as a lot of the oxidizers had a tendency to oxidize the missile itself if left alone for too long. I didn't see this soon enough, but I had some documents open last week that claimed three weeks was the maximum time some of these things could be stored and after that the missile had to be defuelled and inspected for damage caused by the oxidizer (RFNA is nasty, high-test Hydrogen Peroxide is not all that much better; and some of the fuels used were just as bad).
Click to expand...
First generation storable propellant missiles were limited to 30 days for those reasons.

The Soviets then invented the technique of "ampulization", which allowed extending that to 5+ years in the second generation (and later to even longer in subsequent generations – 10+ years in the third generation, and 15+ years in the fourth generation).

Ampulization involved the use of special seals and membranes to isolate the propellant/oxidizer tanks from the delicate engines. This is part of why ampulized missiles could be left alone without maintenance for so long – the delicate components were totally isolated from the corrosive fuel.

Additional measures were taken to stabilize the oxidizer in order to allow for extended storage lives. There are at least two known methods of stabilizing the oxidizers in such a way that largely inhibits its ability to damage the tank that it's stored in. One of these has the disadvantage that it modifies the freezing point of the oxidizer enough to require that silos be steam heated during the winter, but this was hardly a dealbreaker to the Soviet Union. The other method has no such downside.

Another measure that was taken was to use corrosion resistant meals for the oxidizer tanks, which significantly increases service life.

The propellant used in many of the first generation storable missiles was somewhat prone to degradation over extended periods of time. This issue was resolved by the switch to UDMH in second generation and later missiles.

Ampulization was rapidly deployed starting with second generation storable propellant missiles.

Here is a list of Soviet storable liquid missiles by generation and service life, with their commissioning dates listed. Many of these missiles entered into combat duty prior to their official commissioning dates.

First generation storable (30 days): RT-12/RT-12U (1959/1964), RT-14/RT-14U (1961/1963), RT-16/RT-16U (1961/1963)

Second generation storable (5+ years): R-36 (1967/1968/1970), UR-100/UR-100M/UR-100K/UR-100U (1967/1971/1971/1974)

Note that the R-36 initially had a storage life of 5 years, which was later extended to 7.5 years. The UR-100 service life is not specified beyond "several years", so it is possible that it may have been less than 5 years, but in the absence of evidence to the contrary I will assume that it was at least 5 years (similar to the R-36), if not even longer.

Third generation storable (10+ years): MR UR-100/MR UR-100UTTH (1975/1980), R-36M/R-36MUTTH (1975/1980)

Fourth generation storable (15+ years): R-36M2 (1988/1990/1991), UR-100N/UR-100NUTTH (1975/1980)

Note that the UR-100NUTTH had its service life extended to a staggering 21 years.
 
Last edited:
Another way to extend storage-life of a corrosive oxidiser such as RFNA was to add a small quantity of hydrogen fluoride to it (Turning it into IRFNA) as this would then form a corrosion proof fluoride layer coating the tank walls.
 
Last edited:
16 silos per Vanguard class SSBN

12 for the Dreadnought class SSBN

So it's logical to have one full set of silos for storing Trident on land. As there should only be one submarine in dock for maintenance.

But 4 SSBN implies a maximum of 64 Trident missiles currently.

Much talk in peacetime of having just 8 silos filled. Unclear if actually true.
But 8 implies you could store two such half load outs.

Older documents imply 16 is a more military number and 8-12 is political interference.

Equally ABM defence studies suggested it needs roughly 200 RVs to overwhelm the sort of defence Moscow ABM has and deliver sufficient effects.

All of which carries implications for the parsimony of not have a fifth SSBN.
But back when target SSN number was 20.....
 
zen said:
16 silos per Vanguard class SSBN

12 for the Dreadnought class SSBN

So it's logical to have one full set of silos for storing Trident on land. As there should only be one submarine in dock for maintenance.

But 4 SSBN implies a maximum of 64 Trident missiles currently.

Much talk in peacetime of having just 8 silos filled. Unclear if actually true.
But 8 implies you could store two such half load outs.

Older documents imply 16 is a more military number and 8-12 is political interference.

Equally ABM defence studies suggested it needs roughly 200 RVs to overwhelm the sort of defence Moscow ABM has and deliver sufficient effects.

All of which carries implications for the parsimony of not have a fifth SSBN.
But back when target SSN number was 20.....
Click to expand...
Warhead numbers were 225 but I think that got increased to 240, but with some talk of 260. I'd guess there's probably about 5 MIRVs per missile at present - 48x5.
 
I vaguely reccal they dropped to 190 or so but since Boris's authorisation to "upto 260" (which is probably rooted in current limits of sustainment) the official statements have stopped. Both to increase 'ambiguity' and to avoid public discourse over numbers. Which could be problematic.

Which you can read as avoiding hard questions over "why be available numbers so low" to "you be building how many!!!!" And everywhere in between.

Which reflects tensions between military and political views on numbers and ideological issues.

And of course since 2022 and now 2025 there has likely been a significant shifts in who's views carry weight in these decisions. Likely seeing patriots and the military gaining ground.
 
zen said:
Equally ABM defence studies suggested it needs roughly 200 RVs to overwhelm the sort of defence Moscow ABM has and deliver sufficient effects.
Click to expand...
It's actually quite a bit more than that. You'd need at least 200 RVs just to take out the ABM system. That doesn't count any of the RVs that'd be allocated to strike any of the actual targets within the Moscow area!

For example, if you're performing 2:1 strikes on 100 targets within the Moscow ABM system's umbrella, then you'd need 400 RVs to disable those 100 targets (200 to disable the ABM system, then 200 more to strike the 100 discrete targets once the ABM system has been taken out of service).

In 1968, there were thought to be approximately 130 warheads allocated to target the Soviet ABM systems, of which at least 70 were dedicated to the Moscow ABM system alone. This does not even include any of the warheads allocated towards targeting the various civilian and military sites within Moscow! That is just the warheads assigned to suppress the Soviet ABM systems to a sufficient degree to allow those other warheads to be able to hit their targets.

Of those 130 warheads, six targeted the Dog House radars, sixty-four targeted the eight ABM launch complexes, forty-eight targeted the six Tallinn system launch complexes, and twelve targeted the two Hen House early warning radars.

You can see a breakdown in https://journals.sagepub.com/doi/10.2968/060002018 (see the table titled "Projected U.S. ABM suppression strike, 1968")

At another unknown point in the Cold War, 200 warheads had been allocated to target the Tallinn ABM system alone (which is 4x the number from the estimate for 1968). See the quote and image in this post: https://www.secretprojects.co.uk/threads/spartan-sprint-abm-and-derivatives.8778/post-874925

During the cold war, there were 179 Designated Ground Zeros (DGZs) within Moscow. That means up to 179 sites within Moscow could be targeted during a nuclear exchange. Depending on the type of site, anywhere from 1–3 warheads might be targeted on it. Most important military targets will have a minimum of 2 warheads targeted on them. The most critical and/or heavily hardened sites will have 3+ warheads assigned to target them. Sites protected by ABM systems may also independently have additional warheads allocated to them in order to assist with breaking through ABM systems and protect against attrition by ABM interceptors.

Ref: https://nsarchive2.gwu.edu/nukevault/ebb538-Cold-War-Nuclear-Target-List-Declassified-First-Ever/

So during a nuclear exchange between the US and the Soviet Union, Moscow could potentially quite easily have several hundred nuclear warheads targeting it and its ABM system.

The logical conclusion to be drawn from this is that the UK lacks the ability to credibly strike targets within Moscow with nuclear weapons.

However by simply bypassing Moscow entirely and exclusively targeting military/infrastructure/industrial/civilian targets that lie outside of the Moscow ABM umbrella, the UK nuclear deterrent is still more than adequate to instantly cripple Russia.

For a last resort absolute minimum viable retaliatory strike capability like the UK has, this is arguably an acceptable compromise.

The Moscow ABM system is interesting as it inherently skews warhead numbers in Russia's favor when it comes to arms control treaties (even more so than they are already skewed by factors like tactical weapons not being counted). It's kind of funny how the Russian response to the US GMD system has been total outrage, when they already possess a far more capable system protecting their capital city. Pretty hypocritical if you ask me. Sure, you can arguably just bypass Moscow entirely, but I somehow doubt that the US would ever accept that kind of limitation.
 
It all depends.....
OK JTR 'on your horse', correction incoming. Because yes, sometimes my old memory doesn't always come up with the perfect recall.
-----
If the UK is loading something like 12 RVs per missile, that's 192 per boat.

Assuming only one boat load fires off.
Obviously if two boats had a full loadout that's 384.

If by some miracle they had three boats able to fire (maybe one tied up).....576

But OBVIOUSLY at the MOMENT that's well beyond current numbers of warheads the UK is BELIEVED to field.
 
Last edited:
zen said:
If the UK is loading something like 14 RVs per missile, that's 224 per boat.
Click to expand...
The Trident II D5 tops out at 12 RBs per missile with Mk4/W76 RBs (or 8 per missile with Mk5/W88 RBs). It is physically impossible for it to carry 14 RBs.

12 RBs/missile * 16 missiles = 192 RBs per boat

However Britain is only deploying 8 missiles per submarine.

12 RBs/missile * 8 missiles = 96 RBs per boat

And the successor to the current submarine will only have 12 missile tubes.

12 RBs/missile * 12 missiles = 144 RBs per boat

Of course this totally ignores the major problem of the UK not having enough operational warheads to deploy a full loadout.

In reality, each boat is thought to carry only 40 RBs.

zen said:
Assuming only one boat load fires off.
Obviously if two boats had a full loadout that's 448.

If by some miracle they had three boats able to fire (maybe one tied up).....676

Bit Obviously at the moment that's well beyond current numbers of warheads.
Click to expand...
The UK only possesses 225 warheads in total.

Of these 225 warheads, only 120 are operationally available.

Of the 120 operationally available warheads, only 40 are deployed on the single SSBN that is at sea.

40 warheads / 8 missiles = 5 warheads per missile

(alternatively, 40 warheads / 16 missiles = 2.5 warheads per missile, or 40 warheads / 12 missiles = 3.3 warheads per missile)

Source for warhead numbers: https://thebulletin.org/premium/2024-11/united-kingdom-nuclear-weapons-2024/

So if one boat fires off, that's 40 RBs.

If two boats fire off, that's 80 RBs.

If three boats fire off, that's 120 RBs.

Let's say the British by some miracle restore 100% of their stockpile to operational status, and that all political constraints on uploading warheads are eliminated. Let's also further assume that only around 15% of the stockpile is withheld from the operational use pool (in reality this would probably be higher). In this case we can assume approximately 33 warheads are withheld, and 192 are available for operational use. In this case, we would see the following:

If one boat fires off, that's 64 RBs.

If two boats fire off, that's 128 RBs.

If three boats fire off, that's 192 RBs.

We can see that today, even if Britain fired off every single potentially available submarine's full load, they would fall drastically short of being able to take out the Moscow ABM shield, let alone hit anything inside Moscow.

We can also see that in a scenario where Britain restores 100% of their stockpile to operational status and all political constraints on uploading warheads are eliminated, even if Britain fired off every single potentially available submarine's full load, they would still fall short of being able to take out the Moscow ABM shield, let alone hit anything inside Moscow.

Lastly, we can also see that if Britain somehow packed its entire arsenal onto two boats (wildly implausible to the point of absolute absurdity for countless reasons), the 225 warheads would only just barely be enough to take out the Moscow ABM shield, leaving a grand total of 25 warheads for use on actual targets. Assuming standard 2:1 targeting, that allows for hitting a measly 12 actual targets. I don't consider 12 targets to be anywhere near enough to cripple a country the size of Russia.

In short, forget about attacking Moscow. The UK simply doesn't have enough nuclear warheads to even begin to consider it. Honestly there are only two countries in the world that stand a chance – China and the United States.
 
The Moscow ABM system has a total of 68 interceptors. If the do two on one targeting that's only 34 RVs that can be hit. If the British have any sort of penaids on Trident, that's even less RVs being hit. A single boat with 40 RVs, should be able to get half into Moscow. Wether 20 warheads is enough is a whole other question.
 

Similar threads

Back
Top Bottom