Columbia-class SSBN (SSBN-X Future Follow-on Submarine)

The machinery spaces are larger due to the electric drive, life-of-boat reactor, and additional quieting. The reactor itself is further forward due to the reduced missile count meant to conform to arms control/reduction.

But also, neither of those two images have especially accurate dimensions. They're handy for showing work share and manufacturing process but the actual size of the segments doesn't really match up.

Here's what the Navy was showing officially in 2014. Nothing major should have changed since then. Obviously the RC and aft are hidden but you can see roughly how big they should be relative to the missile compartment and front end stuff.

0882602.png
 
The machinery spaces are larger due to the electric drive, life-of-boat reactor, and additional quieting. The reactor itself is further forward due to the reduced missile count meant to conform to arms control/reduction.

Why would arms control be a consideration when no treaty will be in force when Columbia enters service?
 
They cut the number of missiles because they dont need a load of empty tubes, the Ohio class when first built had 24 Trident tubes but that was cut to 20 tubes while only 12 nuclear armed Trident missiles are carried as standard nowadays. So even cutting its capacity to 16 doesn't degrade their operating firepower still leaving 4 spare tubes for other uses such as diver equipment.

My understanding is that the SSBN force still deploys with twenty missiles but reduced war loads, averaging to around four per missile.
 
But also, neither of those two images have especially accurate dimensions. They're handy for showing work share and manufacturing process but the actual size of the segments doesn't really match up.

Here's what the Navy was showing officially in 2014. Nothing major should have changed since then. Obviously the RC and aft are hidden but you can see roughly how big they should be relative to the missile compartment and front end stuff.

View attachment 716924

Wow, that’s a really large engineering/reactor section.
 
Why would arms control be a consideration when no treaty will be in force when Columbia enters service?
A treaty was when the class was designed, and the intention is to have a new agreement in the future. Wouldn't want to be in a Peacekeeper situation with the SSBNs. At this point there's little reason to increase costs adding additional SLBMs, nobody's putting more on their boats and nobody's demonstrating an ability to attrit our boomers sufficiently to threaten deterrence.
 
A treaty was when the class was designed, and the intention is to have a new agreement in the future. Wouldn't want to be in a Peacekeeper situation with the SSBNs. At this point there's little reason to increase costs adding additional SLBMs, nobody's putting more on their boats and nobody's demonstrating an ability to attrit our boomers sufficiently to threaten deterrence.

There is no mechanism to renew New START. It expires in 2026 and that’s it. I cannot believe that the design assumed a new weapons limit treaty would come into force, and moreover the easy way to work around such a constraint is to build less subs, not install less tubes. I assume the reduction from 24 to 16 is for technical reasons.
 
There is no mechanism to renew New START. It expires in 2026 and that’s it. I cannot believe that the design assumed a new weapons limit treaty would come into force, and moreover the easy way to work around such a constraint is to build less subs, not install less tubes. I assume the reduction from 24 to 16 is for technical reasons.

This is revisionist history.

New START came into effect in 2011, and the Russians were actively trying to extend it or negotiate a successor treaty until mid-2021. The specifications for what became the Columbia class were set in 2014. So, there was a treaty in effect when those specs were set, and there was good reason to believe that it might be extended or replaced. It got harder after the INF collapse, but there was a possibility right up until Russia invaded Ukraine.
 
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This is revisionist history.

New START came into effect in 2011, and the Russians were actively trying to extend it or negotiate a successor treaty until mid-2021. The specifications for what became the Columbia class were set in 2014. So, there was a treaty in effect when those specs were set, and there was good reason to believe that it might be extended or replaced. It got harder after the INF collapse, but there was a possibility right up until Russia invaded Ukraine.

It is not revisionist; my understanding is that there was only one 2021 renewal built into the treaty. There was never any mechanism to extend it past 2026 even if Russia turned its T-90s into flower planters. More over New START in no way limited launchers per platform; it only limited total number of deployed/undeployed launchers (700/800). You counter those restrictions by just having less submarines. That is, unless you didn’t already have a fleet of 18x24 launchers in the water that would be expensive to just scrap. Hence SSGNs and four tubes filled with concrete for the rest of the fleet.
 
They cut the number of missiles because they dont need a load of empty tubes, the Ohio class when first built had 24 Trident tubes but that was cut to 20 tubes while only 12 nuclear armed Trident missiles are carried as standard nowadays. So even cutting its capacity to 16 doesn't degrade their operating firepower still leaving 4 spare tubes for other uses such as diver equipment.
As of 2006, the boats still went out with full tubes.
 
my understanding is that there was only one 2021 renewal built into the treaty. There was never any mechanism to extend it past 2026 even if Russia turned its T-90s into flower planters.

Just because there was no mechanism in New START for automatic extensions doesn't mean it could not be extended or replaced by a follow-on treaty (Newer START). The Russians wanted that until at least 2020, if not 2021.

The Navy studies that led to Columbia looked at force numbers as well as missiles. Cutting the fleet below 12 boats doesn't leave enough subs at sea when you account for overhauls, crew turnovers, etc. so you can't get away with fewer than 12 subs, even if you add missiles to keep the total number of launchers constant.
 
Just because there was no mechanism in New START for automatic extensions doesn't mean it could not be extended or replaced by a follow-on treaty (Newer START). The Russians wanted that until at least 2020, if not 2021.

The Navy studies that led to Columbia looked at force numbers as well as missiles. Cutting the fleet below 12 boats doesn't leave enough subs at sea when you account for overhauls, crew turnovers, etc. so you can't get away with fewer than 12 subs, even if you add missiles to keep the total number of launchers constant.
I don't see any nuclear treaties with Russia being extended, especially without looping China into it somehow. It would be insanity to tie our hands at this point.
 
I don't see any nuclear treaties with Russia being extended, especially without looping China into it somehow. It would be insanity to tie our hands at this point.
Well yes, but back when the Columbia was being designed, a new START treaty was still a serious possibility. It's not like they started design work in march 2022.
 
Well yes, but back when the Columbia was being designed, a new START treaty was still a serious possibility. It's not like they started design work in march 2022.
No kidding. I don't see why they couldn't do a "Block II" stretch though given current circumstances. Better yet, just up the number built.
 
No kidding. I don't see why they couldn't do a "Block II" stretch though given current circumstances. Better yet, just up the number built.
The missile tubes are designed as a set of 4, so you're adding a good 25ft in length with a single extra quadpack (20 missiles) and at least 50 with two (24 missiles).

Increasing the number of SSBNs built gets into conflict with the Virgina-replacements.
 
The missile tubes are designed as a set of 4, so you're adding a good 25ft in length with a single extra quadpack (20 missiles) and at least 50 with two (24 missiles).

Increasing the number of SSBNs built gets into conflict with the Virgina-replacements.

And the current length is basically the same as the Ohio class, so there may be an infrastructure constraint at play here.
 
Then you have to consider the need.

As is 16 Tridents with 1 warheads each is enough to bitchslap anyone, let alone with multiple warheads it can and likely does do.

Add in the fact that the newest Tridents are smarter and more capable then the old ones allowing them to aviod ABMs?

Eyeah 16 more then enough to ensure a kill.

And that just one sub.

There going to be 3 out at any one time.


Its not the first cold war anymore where you going to waste a warhead in some African country just so they can feel involve. Nor will we be deleting cities just because they are on the other side.

No all going to head straight to the current PITA who decide to pop the Genie of the Nukes military bases and main government areas.
 
Then you have to consider the need.

As is 16 Tridents with 1 warheads each is enough to bitchslap anyone, let alone with multiple warheads it can and likely does do.

Add in the fact that the newest Tridents are smarter and more capable then the old ones allowing them to aviod ABMs?

Eyeah 16 more then enough to ensure a kill.

And that just one sub.

There going to be 3 out at any one time.
No, there's going to be 8-9 out at any one time, the way the two crew schedule works out every 4 boats puts 3 at sea (roughly)
 
If the PRC triples their nuclear arsenal and deploys 100% of those warheads "soon," adding another 4 tubes to an 826 isn't going to change much other than the cost of an 826.
 
If the PRC triples their nuclear arsenal and deploys 100% of those warheads "soon," adding another 4 tubes to an 826 isn't going to change much other than the cost of an 826.
Would it even be possible to upload the existing Ohios back to 24?
 
Yes it’s worse with two nuclear peer adversaries who will soon have double the number of deployed warheads as us.

That seems doubtful. I suspect the U.S. starts uploading its missiles once New START formally expires, and there are enough W76 and W78s in storage to double the load of the existing missiles (presumably the 50 empty silos could be refilled as part of that). The Russians might upload as well, but their missiles are already carrying much heavier loads to begin with.
 
Would it even be possible to upload the existing Ohios back to 24?

Not in a cost effective fashion. Plus the threat is in the future when the Ohios are being retired. The current fleet could easily have its warhead count expanded.
 
That seems doubtful. I suspect the U.S. starts uploading its missiles once New START formally expires, and there are enough W76 and W78s in storage to double the load of the existing missiles (presumably the 50 empty silos could be refilled as part of that). The Russians might upload as well, but their missiles are already carrying much heavier loads to begin with.
The easiest temporary move would be to double the current Trident loads from 4 to 8 and bring back 50 MMIIIs and triple load 250 of the MMIIIs, that would take the number of ICBM/SLBM warheads up to 2870. Replacing the 4 filled tubes on the Ohios would increased that to 3254. There were also at least 400 AGM-129s and another 200 AGM-86s deployed at one point, so maybe bring them back too to take the overall strategic count to 4354 + 288 bombs.
 
Would it even be possible to upload the existing Ohios back to 24?

Remove the filled tubes and replace them. Presumably there's some way of removing tubes in case one fails.
Doubtful as the Ohios, especially the SSGNs, are coming up on retirement. Money is tight and I can't see the navy sparing the funding. I hope I'm wrong however, as the SSGNs add alot of needed VLS tubes. In fact, I hope we eventually see some of the Columbia class made into SSGN. Even a dumbed down variant arsenal ship of the Columbia without all the extra Nuclear C4ISR and stealthiness would give you 16 tubes with ~7 Tomahawk or LRASM. ALSO GIVES capacity for Hypersonics.
 
The easiest temporary move would be to double the current Trident loads from 4 to 8 and bring back 50 MMIIIs and triple load 250 of the MMIIIs, that would take the number of ICBM/SLBM warheads up to 2870. Replacing the 4 filled tubes on the Ohios would increased that to 3254. There were also at least 400 AGM-129s and another 200 AGM-86s deployed at one point, so maybe bring them back too to take the overall strategic count to 4354 + 288 bombs.

I think AGM-129s are long gone, but open source estimates are that 250 AGM-86 are active at Minot with a similar number in storage at Kirtland. When it comes to bomber leg of the triad, the U.S. is in a superior position, both in terms of means of delivery and weapons development. The B-52 force will be upgraded, the B-21 likely has greatly superior range to the B-2, and LRSO and B-61 mod 12/13 should give both effective high precision delivery.
 
The easiest temporary move would be to double the current Trident loads from 4 to 8 and bring back 50 MMIIIs and triple load 250 of the MMIIIs, that would take the number of ICBM/SLBM warheads up to 2870. Replacing the 4 filled tubes on the Ohios would increased that to 3254. There were also at least 400 AGM-129s and another 200 AGM-86s deployed at one point, so maybe bring them back too to take the overall strategic count to 4354 + 288 bombs.
I doubt command would be willing to reveal the position of An SSBN for a conventional attack, but I like the concept. Gives use to a very expensive platform that essentially goes/will go unused for its entire career besides deterrence.
 
I doubt command would be willing to reveal the position of An SSBN for a conventional attack, but I like the concept. Gives use to a very expensive platform that essentially goes/will go unused for its entire career besides deterrence.
This is nothing to do with conventional attack, it's about increasing the warhead load on the currently deployed 240 missiles.
 
This is nothing to do with conventional attack, it's about increasing the warhead load on the currently deployed 240 missiles.
My bad, I was making breakfast and taking care of kiddos when I read that part of the tread, thought you wanted to reactivate the unused tubes to fill them with conventional tomahawk. I read cruise missles and immediately jumped to tomahawks.
 
Just a reminder for all the “we can do this we can do that”

We seem to be having a lot of trouble building a new ICBM so these Triad expansion/warhead upload plans seem rather “pie in the sky” to me.
——————————————
From analysis Strategic Posture Report
“…
The October 2023 bipartisan Congressional Strategic Posture Commission’s report contained two important insights concerning the implications of China’s nuclear weapons buildup: 1) the United States will soon be threatened not by “one, but two nuclear peer adversaries, each with ambitions to change the international status quo, by force,” and 2) that China will achieve “…rough quantitative parity with the United States in deployed nuclear warheads by the mid-2030s.” Unfortunately, the situation is likely even worse. On August 12, 2021, the Commander of U.S. Strategic Command Admiral Charles Richard summed it up: “We are witnessing a strategic breakout by China….The explosive growth in their nuclear and conventional forces can only be what I described as breathtaking.”…..
 
I do not think it is a stretch to add existing warheads to existing missiles. The last several MM3 tests were done with inert warheads. Reactivating the four Ohio tubes is a non starter for cost reasons, nor is it remotely necessary within the lifetime of the SSBN force.
 
Just a reminder for all the “we can do this we can do that”

We seem to be having a lot of trouble building a new ICBM so these Triad expansion/warhead upload plans seem rather “pie in the sky” to me.
——————————————
From analysis Strategic Posture Report
“…
The October 2023 bipartisan Congressional Strategic Posture Commission’s report contained two important insights concerning the implications of China’s nuclear weapons buildup: 1) the United States will soon be threatened not by “one, but two nuclear peer adversaries, each with ambitions to change the international status quo, by force,” and 2) that China will achieve “…rough quantitative parity with the United States in deployed nuclear warheads by the mid-2030s.” Unfortunately, the situation is likely even worse. On August 12, 2021, the Commander of U.S. Strategic Command Admiral Charles Richard summed it up: “We are witnessing a strategic breakout by China….The explosive growth in their nuclear and conventional forces can only be what I described as breathtaking.”…..
Uploading the Ohios should be a pretty straight forward thing as the D-5 is still in production.
 
I think it is pretty clear there is no immediate threat to the U.S. deterrent and in the medium term, it seems like there are plenty of possibilities. The problem to my mind is only a dozen 16 tube SSBNs. But I assume that probably can be solved with the simple expedient of more boomers if the strategic situation demands it.
 
Would it even be possible to upload the existing Ohios back to 24?
Depends on whether they filled the unused tubes with ballast cans or poured concrete into them.

Ballast cans with some grout around the outside are removable with work, the C4 Ohios had D5 diameter tubes with a liner grouted in place which got pulled out for their D5 Backfits.

Tubes with concrete poured in are best removed entirely, and I don't know how complex that would be.
 

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