M51 for Successor/Dreadnought Class SSBN?

The silo compartment might need replacing with silos built to take M51.

But France could supply the fuel, potentially a full motor to replace Trident.
 
zen said:
The silo compartment might need replacing with silos built to take M51.

But France could supply the fuel, potentially a full motor to replace Trident.
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I'm guessing they would jump at the possibility of someone else supporting solid fuel manufacture.
 
PMN1 said:
I'm guessing they would jump at the possibility of someone else supporting solid fuel manufacture.
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I dunno.

The current arrangement is that the US provides the missile and the UK provides the warheads. So when the US went through the D5 Life Extension process, that was applied to all the missiles. Including the UK missiles.
 
Scott Kenny said:
I dunno.

The current arrangement is that the US provides the missile and the UK provides the warheads. So when the US went through the D5 Life Extension process, that was applied to all the missiles. Including the UK missiles.
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Oh I meant the French jumping at the chance of someones else helping with the support of largeish diameter solid fuel manufacture.

On a separate note, the CMC's that are going to be used in both UK and US boats.....are all the components made in the US?
 
PMN1 said:
Oh I meant the French jumping at the chance of someones else helping with the support of largeish diameter solid fuel manufacture.
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Ah, gotcha!


PMN1 said:
On a separate note, the CMC's that are going to be used in both UK and US boats.....are all the components made in the US?
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Not sure. I know the design is the same, and I'd suspect that Missile Control Center and Navigation Center are US supplied. But I thought that the UK made the actual Missile Compartment, tubes, etc.
 
When the Labour Government looked at cancelling Polaris in 1965 it was suggested that the R class subs already laid down could have the missile tube section removed.
I wonder if the Dreads could have a French missile compartment inserted if events needed it.
 
uk 75 said:
When the Labour Government looked at cancelling Polaris in 1965 it was suggested that the R class subs already laid down could have the missile tube section removed.
I wonder if the Dreads could have a French missile compartment inserted if events needed it.
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It probably would be simpler to design a new missile compartment that could work with the French missiles. The French missile compartment is two feet smaller in diameter and of course will have totally different piping and tankage. Since the changes in weight would be amidships, you could probably figure out a way to make it work with the existing fore and aft ends, but submarines are such sensitive (longitudinal balance-wise) designs that the fore and aft ends may need to be changed to some extent. For example, when the Skipjack SSN design was turned into the George Washington SSBN design, internal main ballast tanks had to be added in the fore and aft Skipjack ends. Something similar happened when the Valiant SSN design was turned into the Resolution SSBN design.
 
Vepr157 said:
It probably would be simpler to design a new missile compartment that could work with the French missiles. The French missile compartment is two feet smaller in diameter and of course will have totally different piping and tankage. Since the changes in weight would be amidships, you could probably figure out a way to make it work with the existing fore and aft ends, but submarines are such sensitive (longitudinal balance-wise) designs that the fore and aft ends may need to be changed to some extent. For example, when the Skipjack SSN design was turned into the George Washington SSBN design, internal main ballast tanks had to be added in the fore and aft Skipjack ends. Something similar happened when the Valiant SSN design was turned into the Resolution SSBN design.
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If time was available, I think the better option would be to keep the UK missile compartment diameter, and install new tubes plus replace all the electrical with 220v UK/European standard.

I think replacing the tubes wouldn't be terrible, IIRC they're not welded to the hull, but redoing the electrical and fire control would not be fun.
 
Of course if we had hedged our bets, we'd have asked France for their tubes technical package and run a parallel design of compartment with them instead. Which would make the transition much simpler.
 
I understood the missile compartment in the UK SSBN’s has been made in the US, then transported across the Atlantic on a barge whereupon it’s sandwiched between a UK built front and back end. So suggesting changing out tubes is not going to happen.

I’ve been having similar thoughts about M51 recently. It’s not commonly understood that the UK doesn’t own its Trident’s missiles;- they’re effectively leased from the USN stockpile, collected at the beginning of each patrol and returned at the patrol end.
 
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This is really a weird, if not obtuse, way to support a nuclear deterrent. Even more with warheads and submarines being british. And missiles not the most expansive part, solid fuel in composite tubes...
 
This is what was published in Aug 2024 in a UK Govt paper about the Common Missile Compartment for the Dreadnought and Columbia classes.

"A Common Missile Compartment (CMC) for the SSBN, which will house the
current Trident strategic weapons system, is being developed in conjunction
with the United States.5"

"5 The US is replacing its current SSBN fleet with a new Columbia class SSBN, which is due to enter service within a similar timeframe to the UK’s Dreadnought programme (early 2030s). Design for the Dreadnought’s common missile compartment (CMC) is being delivered under the 1963 Polaris Sales
Agreement (PSA), as amended (HL Deb 11 February 2013, c92WA). Each SSBN will have three missile compartments, each with four missile tubes, for a potential total of 12 missiles per submarine"

And

"As outlined above, the Common Missile Compartment for the submarine is
also a collaborative programme with the United States. American company
General Dynamics is the prime contractor for the CMC and is working in co-
operation with BAE Systems to ensure that the design accommodates UK
requirements for the Dreadnought class. In October 2016 Babcock
International was awarded a contract by General Dynamics to manufacture
22 tactical missile tubes as part of the overall CMC project. That work is
taking place in Rosyth, securing approximately 150 jobs. Whether this work on
the CMC forms part of BAE Systems’ UK supply chain spend, is unclear."

And

"As with previous SSBN, the submarine will be built by BAE Systems in Barrow-
in-Furness and the propulsion system will be built by Rolls Royce at
Raynesway, Derby."

(my emphasis in bold)



Note the CMC for both classes comes in 4 missile blocks - 3 in Dreadnought & 4 in Columbia.

This article refers to various contracts to GD for development and "installation" works on various systems in both classes. Doesn't say where the installation will occur.
www.naval-technology.com

Dreadnought-Class Nuclear-Powered Ballistic Missile Submarines

The Dreadnought-class ballistic missile submarines will help maintain the UK’s Continuous at Sea Deterrence (CASD) capability.
www.naval-technology.com www.naval-technology.com

So while development is by General Dynamics in the US, actual construction of the missile blocks is less clear, but some elements of those blocks are being produced in the UK. But I note the reference to "the submarines" being built in the UK, not that only part (I.e. entire sub less missile compartment as suggested by Z42) will be.

That is the problem nowadays. Where do all the bits come from? So how much is "construction" and how much is "assembly" of components / blocks "constructed elsewhere.

Specialist steel for the Dreadnoughts is being sourced from France.
 
I would assume that its to late and costly to change Dreadnought to M51 but considering the current state on could create alternative developments. A smaller version for example which may even be something for SSN-Aukus or as retrofit into the current Vanguards which one could use in a stationary Position like an "cheap" Silo solution
 
Zoo Tycoon said:
I understood the missile compartment in the UK SSBN’s has been made in the US, then transported across the Atlantic on a barge whereupon it’s sandwiched between a UK built front and back end. So suggesting changing out tubes is not going to happen.
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To add to what @EwenS wrote, the British missile compartments have always been designed in the U.S. but built in Britain.
 
Vepr157 said:
To add to what @EwenS wrote, the British missile compartments have always been designed in the U.S. but built in Britain.
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The information comes from a source who worked on the Vanguard class and specifically said the same was true for the Resolution boats. Reproduced in good faith.

I understand the M51 motors are designed and made by Roxal which is a joint Anglo French company although I expect all of the M51 IP is owned by the French Government.
 
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