Current Nuclear Weapons Development

[Scott Kenny]

Yeah, I know it's because the new class physically lacks space to cram in more missiles, and that the increased uptime due to reduced service requirements will partially compensate for the reduced number of missiles, and that it's also at least somewhat likely that additional boats may eventually get ordered to ultimately end up with a overall fleet composition similar to the current 20 missile configuration Ohio SSBN fleet in terms of the total number of active tubes in service at sea at any given time... But if we go back to 24 missile configuration Ohio class SSBNs, then that causes some interesting new questions to arise regarding the composition of the future replacement Columbia class SSBN fleet.

It may be possible to add a single quad of missiles without completely fubaring the Columbia-class weight&balance.

It would probably require a total redesign to put a Columbia-class up to 24 tubes.

 

[JTR]

It may be possible to add a single quad of missiles without completely fubaring the Columbia-class weight&balance.

It would probably require a total redesign to put a Columbia-class up to 24 tubes.

The limit isn't actually the submarine here, it's the submarine infrastructure, primarily dry docks and piers. They were all designed to accommodate boats up to the size of the Ohio class, which is 560 feet long. Anything significantly larger than that simply wouldn't fit into existing facilities.

The 16 tube Columbia class is 560 feet long, exactly the same length as the 24 tube Ohio class. The new electric drive basically eats up 8 missile tubes worth of space.

Larger variants of the Columbia class were studied during design work for the class. From a purely economic perspective, a 24 tube (or even larger) submarine would be ideal, especially coupled with the higher availability of the Columbia class – you could build and operate far fewer boats.

But there are a bunch of downsides to doing that as well, even more so given the decision to attempt to significantly downsize the submarine force while simultaneously shifting to a platform with much higher availability (which translates to fewer total boats required in order to keep the same number of boats continuously at sea).

I really don't think the choice to downsize to 16 tubes was a mistake. It made considerable sense to go with 16 tubes, especially so at the time in the environment that decision was made in. I think the choice to limit initial procurement to only 12 boats was the only real mistake.

But even that decision is arguably not that terrible, given that they can and likely will end up ordering additional boats.

It also likely wasn't politically feasible at the time to increase initial procurement beyond 12 given the way they planned the design requirements (a hellish compromise between economics, defense needs, nuclear arms reduction treaty demands, and over-optimistic predictions of continued reductions in nuclear weapons from future nuclear arms reduction treaties).

I'd imagine the fact that the current D5 missiles seem to be fairly heavily offloaded in order to meet treaty obligations also played a role as well. If you're expecting further follow-on treaties after New START to continue along the same trajectory, then why build for a fleet the same size as the current one? Even if you need to maintain the capability to upload missiles in an emergency, you don't necessarily need as much upload margin as we currently have available, especially in a future environment of the kind that was predicted at the time, where future arms control treaties would have even more severely cut down on the maximum numbers of warheads and launchers.

The sudden outbreak of full-scale war in Ukraine, near total disintegration of New START with no replacement on the horizon, and China's unexpectedly aggressive nuclear buildup (among many other recent major geopolitical issues) have dramatically changed the nuclear threat environment almost beyond recognition in a very short time period. I don't blame the designers for failing to predict all of this.

Here's a highly relevant article that covers most of the issues relevant to the Columbia class design choices: https://www.realcleardefense.com/ar...out_redesigning_the_columbia_ssbn_824714.html

 

[Scott Kenny]

The limit isn't actually the submarine here, it's the submarine infrastructure, primarily dry docks and piers. They were all designed to accommodate boats up to the size of the Ohio class, which is 560 feet long. Anything significantly larger than that simply wouldn't fit into existing facilities.

4 extra tubes would be about 25 feet longer, which will fit into the drydock at Delta Pier.

 

[JTR]

4 extra tubes would be about 25 feet longer, which will fit into the drydock at Delta Pier.

Looking at measurements, while it would probably physically fit as long as it's only a single 4-pack worth of length added, the amount of laydown area (and slack space) would be significantly decreased, which may pose operational challenges.

I'm also not quite sure which facilities specifically are the bounding condition for a longer SSBN. Presumably there are multiple dry docks and piers affected, and possibly other facilities as well.

I was going to mention the covered explosives handling wharfs used to load and unload Trident missiles, but after briefly looking into them, I think all of them could probably handle a small (single 4-pack) increase with no significant modifications. A larger increase might be iffier for the ones at Kings Bay (the approach to those looks kind of dicey). However I suspect you could probably still make them work for larger variants.

Based on the little that is known about Columbia's dimensions, it seems most of the added length is from the engine compartment. If that's truly the case, then in theory I think you could probably even reuse the existing EHW facilities for a 24 tube Columbia variant. I may be overestimating the space available though. It's hard to tell based on satellite imagery and a scant few photos.

My tentative conclusion based on this is that the dry docks (and maybe piers) are most likely the primary bounding condition, not the explosive handling wharfs (although they may become a restriction for a 24 tube size, and are very likely to become a restriction if you go past 24 tubes).

Another problem is that even if the facilities restrictions were a total non-issue, it's not as simple as just welding an extra 4-pack into the hull.

First, you'd need to do something to ensure the ballasting remains adequate despite the considerable amount of extra added weight. My understanding is that with these SSBNs, that is non-trivial and requires significant changes to areas outside of the missile compartments.

In theory you could probably make the ballasting issue work if you throw enough time and money at the problem. The question is just how much extra time and money would it take? You cannot delay retirement of the Ohio class SSBNs forever, and there is already going to be a significant gap where at-sea boat counts dip below the minimum desired threshold during the Ohio to Columbia transition. A major redesign could cause years of delay and compromise the schedule of the entire program. It's also not ideal to have two significantly different configurations of the same boat active.

However, I just dug up one of my archived studies on the Columbia SSBN, and it brings up entirely new concerns that make the prospect of expanding the Columbia beyond 16 tubes sound even less feasible than the ballast and redesign issues had already made it.

https://www.congress.gov/crs_external_products/R/PDF/R41129/R41129.157.pdf (see Appendix D on PDF page 56)

Footnote 95: At a March 30, 2011, hearing before the Strategic Forces subcommittee of the Senate Armed Services Committee, Admiral Kirkland Donald, Deputy Administrator for Naval Reactors and Director, Naval Nuclear Propulsion, National Nuclear Security Administration, when asked for examples cost efficiencies that are being pursued in his programs, stated the following:

The—the Ohio replacement [program] has been one that we’ve obviously been focused on here for—for several years now. But in the name of the efficiencies, and one of the issues as we work through the Defense Department’s acquisition process, we were the first program through that new process that Dr. [Aston] Carter [the DOD acquisition executive] headed up.

But we were challenged to—to drive the cost of that ship down, and as far as our part was concerned, one of the key decisions that was made that—that helped us in that regard was a decision to go from 20 missile tubes to 16 missile tubes, because what that allowed us to do was to down rate the—the propulsion power that was needed, so obviously, it’s a–it’s a small[er] the reactor that you would need.

But what it also allowed us to do was to go back [to the use of existing components]. The size [of the ship] fell into the envelope where we could go back and use components that we had already designed for the Virginia class [attack submarines] and bring those into this design, not have to do it over again, but several of the mechanical components, to use those over again.

And it enabled us to drive the cost of that propulsion plant down and rely on proven technology that’s—pumps and valves and things like that don’t change like electronics do.

So we’re pretty comfortable putting that in ship that’ll be around ‘til 2080. But we were allowed to do that.

(Source: Transcript of hearing.)

Going by that quote and the surrounding context, it sounds like part of the reason why they chose 16 tubes instead of 20 is because with 16 tubes they could use a smaller and cheaper reactor, and then in turn, because of the smaller reactor size, the reactor and propulsion plant would be small enough to allow direct reuse of a substantial amount of components from the Virginia class.

Which means, if they wanted to increase the size of the boat to add on an extra 4 missile tubes, then either the reactor propulsion plant would be significantly undersized for the upsized boat (which sounds like a pretty serious problem for a boat that's expected to serve as our primary at-sea nuclear deterrent for upwards of 40 years), or they would have to undertake an enormously expensive and extremely time consuming program to design a brand new upsized reactor, a brand new upsized propulsion plant, and then design and qualify a whole slew of brand new custom upsized components to replace all of the ones that the smaller variant had been able to reuse from the VA class.

That would be on top of all the work required to fix the ballast issues.

Later on in that appendix they disclose the exact variants under consideration at the time, and the relative force compositions for each option:

The National Defense Authorization Act (NDAA) for Fiscal Year 2012 (FY12) directed the Secretary of the Navy and the Commander of U.S. Strategic Command (USSTRATCOM) to jointly submit a report to the congressional defense committees comparing four different options for the OHIO Replacement (OR) fleet ballistic missile submarine (SSBN) program. Our assessment considered the current operational requirements and guidance. The four SSBN options analyzed were:

1. 12 SSBNs with 16 missile tubes each
2. 10 SSBNs with 20 missile tubes each
3. 10 SSBNs with 16 missile tubes each
4. 8 SSBNs with 20 missile tubes each

The SSBN force continues to be an integral part of our nuclear Triad and contributes to deterrence through an assured second strike capability that is survivable, reliable, and credible. The number of SSBNs and their combined missile tube capacity are important factors in our flexibility to respond to changes in the threat and uncertainty in the strategic environment.

We assessed each option against the ability to meet nuclear employment and planning guidance, ability to satisfy at-sea requirements, flexibility to respond to future changes in the postulated threat and strategic environment, and cost. In general, options with more SSBNs can be adjusted downward in response to a diminished threat; however, options with less SSBNs are more difficult to adjust upward in response to a growing threat.

Clearly, a smaller SSBN force would be less expensive than a larger force, but for the reduced force options we assessed, they fail to meet current at-sea and nuclear employment requirements, increase risk in force survivability, and limit flexibility in response to an uncertain strategic future. Our assessment is the program of record, 12 SSBNs with 16 missile tubes each, provides the best balance of performance, flexibility, and cost meeting commander’s requirements while supporting the Nation’s strategic deterrence mission goals and objectives.

The classified annex contains detailed analysis that is not releasable to the public.

Given how small the gaps truly are, it makes it all too clear that any talk of redesigning the Columbia to cram in more missiles at insane expense is just foolish. We have a good design already. We just need more of them.

Time for some math:

If we assume,

12 Columbia = 10 Columbia => 83% at-sea
14 Ohio = 10 Ohio => 71% at-sea

1 Columbia = 16 tubes = 80% of a 20T-Ohio // 67% of a 24T-Ohio

Baseline = 14 Ohio = 10 Ohio at-sea => 200 tubes at-sea (baseline) // 240 tubes at-sea (breakout)

Replacement = 12 Columbia = 10 Columbia at-sea => 160 tubes at-sea

Equivalency =

80% of baseline 20T-Ohio (160 vs 200, ∆ = -40)

67% of breakout 24T-Ohio (160 vs 240, ∆ = -80)

To obtain 100%, we would need to solve:

Nt = (Na * 16)

Na = 0.83 * N

Nt = ((0.83 * N) * 16

Nt = 0.83 * N * 16

Nt / (0.83 * 16) = N

Nt = 160; 160 / (0.83 * 16) = 12

Now we want to determine how large of a Columbia fleet we would need to meet 100% equivalency to either scenario.

For 20T-Ohio, that would be 200 at-sea tubes, therefore:

Nt = 200; 200 / (0.83 * 16) = 15

For 24T-Ohio, that would be 240 at-sea tubes, therefore:

Nt = 240; 240 / (0.83 * 16) = 18

So in other terms:

Our existing fleet has 14x 20T-Ohio.

With Columbia, the initial order is for 12 boats, which is 20% (40) fewer at-sea tubes than the current 20T-Ohio fleet.

If that order was increased to 15 boats, then Columbia would achieve rough parity with the current 20T-Ohio fleet in terms of number of at-sea tubes. If it was increased to 16 boats, then it would slightly surpass the current 20T-Ohio fleet. Given uncertainties involved and the fractional availability issue, I would say 16 is a safer number. So they just need to order 25–33% (3–4) more boats to close the capability gap.

The possibility of a return to a 24T-Ohio fleet is more problematic. However, even that could be compensated for by simply increasing the Columbia order to 18 boats. This would achieve exact parity with the theoretical breakout 24T-Ohio fleet in terms of number of at-sea tubes. So even in this far less favorable case, they still would only need to order 50% (6) more boats to close the capability gap.

Sure, this is more boats to operate. But in the first case, 15–16 SSBNs would only be 1–2 more than the current number of SSBNs in operation. And in the second case, while it is 4 more SSBNs, we used to operate dozens of SSBNs during the Cold War, operated 18 Ohio class SSBNs for a short time, are technically still operating 18 Ohio class subs today (if you count the SSGN conversions), and had originally planned on a 20–24 boat fleet of Ohio class subs. Furthermore, we're already operating 71 nuclear subs. Adding 1–4 more is only a 1–6% increase in total number of nuclear subs in operation.

I don't think crewing the additional boats is an impossible task – far from it. Yeah, recruiting and training the additional personal is still going to be a non trivial and expensive task as always, but there's a lot of lead time for that.

The real challenge is to somehow convince the House and Congress to approve adding these additional submarines to the initial buy order (and thereby approve increasing the total cost of the Columbia program proportionately, which is a pretty substantial amount of money). That's probably the trickiest part.

 

[Scott Kenny]

Looking at measurements, while it would probably physically fit as long as it's only a single 4-pack worth of length added, the amount of laydown area (and slack space) would be significantly decreased, which may pose operational challenges.

I'm also not quite sure which facilities specifically are the bounding condition for a longer SSBN. Presumably there are multiple dry docks and piers affected. The covered Trident missile loading dock is probably one of the bigger ones to worry about.

The stern sticks out of the Explosives Handling Wharf when Ohios pull in, so that wouldn't be an issue.

IIRC, the major length restriction is that drydock at delta pier (and the matching one at King's Bay, Georgia).

Another problem is that even if the facilities restrictions were a total non-issue, it's not as simple as just welding an extra 4-pack into the hull.

First, you'd need to do something to ensure the ballasting remains adequate despite the considerable amount of extra added weight. My understanding is that with these SSBNs, that is non-trivial and requires significant changes to areas outside of the missile compartments.

In theory you could probably make the ballasting issue work if you throw enough time and money at the problem. The question is just how much extra time and money would it take? You cannot delay retirement of the Ohio class SSBNs forever, and there is already going to be a significant gap where at-sea boat counts dip below the minimum desired threshold during the Ohio to Columbia transition. A major redesign could cause years of delay and compromise the schedule of the entire program. It's also not ideal to have two significantly different configurations of the same boat active.

That's a weight&balance problem, those take about half an hour to do.

Assuming that the engineers know how much one of those quads weighs beforehand. If they don't, well, then they get to figure that out first.

Which means, if they wanted to increase the size of the boat to add on an extra 4 missile tubes, then either the reactor propulsion plant would be significantly undersized for the upsized boat (which sounds like a pretty serious problem for a boat that's expected to serve as our primary at-sea nuclear deterrent upwards of 40 years),

Nah, then you just have painfully slow boomers. Like when the USN had S5W-powered boomers like Polaris/Poseidon.

So in other terms:

Our existing fleet has 14x 20T-Ohio.

With Columbia, the initial order is for 12 boats, which is 20% (40) fewer at-sea tubes than the current 20T-Ohio fleet.

If that order was increased to 15 boats, then Columbia would achieve rough parity with the current 20T-Ohio fleet in terms of number of at-sea tubes. If it was increased to 16 boats, then it would slightly surpass the current 20T-Ohio fleet. Given uncertainties involved and the fractional availability issue, I would say 16 is a safer number. So they just need to order 25–33% (3–4) more boats to close the capability gap.

The possibility of a return to a 24T-Ohio fleet is more problematic. However, even that could be compensated for by simply increasing the Columbia order to 18 boats. This would achieve exact parity with the theoretical breakout 24T-Ohio fleet in terms of number of at-sea tubes. So even in this far less favorable case, they still would only need to order 50% (6) more boats to close the capability gap.

Sure, this is more boats to operate. But in the first case, 15–16 SSBNs would only be 1–2 more than the current number of SSBNs in operation. And in the second case, while it is 4 more SSBNs, we used to operate dozens of SSBNs during the Cold War, operated 18 Ohio class SSBNs for a short time, are technically still operating 18 Ohio class subs today (if you count the SSGN conversions), and had originally planned on a 20–24 boat fleet of Ohio class subs. Furthermore, we're already operating 71 nuclear subs. Adding 1–4 more is only a 1–6% increase in total number of nuclear subs in operation.

I don't think crewing the additional boats is an impossible task – far from it. Yeah, recruiting and training the additional personal is still going to be a non trivial and expensive task as always, but there's a lot of lead time for that.

The real challenge is to somehow convince the House and Congress to approve adding these additional submarines to the initial buy order (and thereby approve increasing the total cost of the Columbia program proportionately, which is a pretty substantial amount of money). That's probably the trickiest part.

I think there's pipeline space and officers available for up to 18 SSBNs. You'd be stretching to get more than that.

 

[Josh_TN]

The SSGN crews should be counted towards current SSBN crews. They are blue/gold, roughly the same size, and will not be replaced with equivalents: the replacement is Virginia blk5, to the extent there is a replacement.

 

[bobbymike]

The U.S. Nuclear Arsenal of 2050: A Proposal for American Survival

The world security environment is deteriorating. The Russian invasion of Ukraine continues unabated. Iranian proxies continue to attack Israel. North Korea regularly threatens to incinerate American and allied cities with nuclear weapons. China is embarking on the largest military expansion in...

www.heritage.org

 

[bobbymike]

In defense of the US maintaining a balanced nuclear triad

The strength of the triad is not just a function of the existence of its three legs, but also of the balance in numbers and capabilities among the three legs.

www.atlanticcouncil.org

 

[NMaude]

Curious Droid recently uploaded a very interesting video about the smallest possible nuke:

In my last video, I looked at how small a nuclear weapon be made, well in this follow up I look at the brilliant yet little-known physicist called Ted Taylor, who pushed the boundaries of nuclear weapons design to extremes. From creating the smallest nuclear bomb ever fielded, the Davy Crockett, to designing the largest pure-fission device, Ivy King, Taylor’s work shaped the Cold War arms race in ways few realize. But did you know that he believed bombs could be made far smaller than most experts thought possible, smaller than the Davy Crockett, and warned that anyone with enough knowledge and access to fissile material could build a crude but viable device. He also exposed the shocking lack of security around nuclear materials in the 1960s and 70s in the US, highlighting just how vulnerable they were to theft or misuse.It looks at one of the most influential yet overlooked figures in nuclear history, the man who made nukes both smaller and more dangerous than ever imagined.​

Theodore Taylor is prominently featured in an excellent 1974 book called The Binding Curve of Energy by John McPhee which is an excellent that I highly recommend.

 

[Flyaway]

I’ve seen a number of posts above regarding this. See below.

Lockheed Martin News@LMNews
The @USNavy's Strategic Systems Programs successfully completed four unarmed Trident II D5 Life Extension (D5LE) missile tests from Sept. 17-21.
@LockheedMartin supported these tests to strengthen the sea-based leg of the nuclear triad. Click for more:

Article: Successful Trident II D5 Life Extension (D5LE) Launches Demonstrate Continued Readiness of Nation’s Sea-Based Deterrent

23 September 2025
From April Crew-Kelly, Navy Strategic Systems Progams Public Affairs

 

[Forest Green]

Tomahawks For Ukraine Talk Elicits New Response From Putin​

Tomahawks For Ukraine Talk Elicits New Response From Putin

As the Trump administration mulls providing Ukraine with long-range cruise missiles, Putin explained how Russia would respond.

www.twz.com

Russian President Vladimir Putin on Friday offered his latest take on the prospect of Ukraine receiving Tomahawk Land Attack cruise missiles (TLAMs) from the United States. During a press conference, the Russian leader also hinted that his country would soon introduce a new nuclear weapon.

 

[Arjen]

October 2: second thoughts on Tomahawks for Ukraine

Trump unlikely to send Tomahawk long-range missiles to Ukraine, Reuters reports

Washington is more likely to provide shorter-range systems or let European allies buy long-range weapons for Ukraine, officials told Reuters.

kyivindependent.com

The U.S. is unlikely to provide Ukraine with Tomahawk long-range cruise missiles, Reuters reported on Oct. 2, citing an unnamed U.S. official and three other sources familiar with the discussions.

https://www.reuters.com/business/aerospace-defense/us-tomahawk-missile-shipments-ukraine-unlikely-sources-say-2025-10-02/

The Trump Administration's desire to send long-range Tomahawk missiles to Ukraine may not be viable because current inventories are committed to the U.S. Navy and other uses, a U.S. official and three sources said.
[...]
a U.S. official and sources familiar with Tomahawk missile training and supplies questioned the feasibility of providing the cruise missiles, which have a range of 2,500 kilometers (1,550 miles).
The U.S. official stressed there was no shortage of the workhorse weapon, which is often used by the military for land attack missions, suggesting other shorter-distance options could be supplied to Kyiv.

 

[NMaude]

The main problem with supplying Tomahawks to Ukraine is the lack of a suitable mobile land-launcher.

 

[Grey Havoc]

Not to mention that, unlike its illustrious predecessor, the Tactical Tomahawk isn't exactly suited to field use, as the USMC found out.

 

[NMaude]

the Tactical Tomahawk isn't exactly suited to field use, as the USMC found out.

Didn't the field tests with the Mk-70 Mod 0 Typhon launcher not work out?

 

[Grey Havoc]

Didn't the field tests with the Mk-70 Mod 0 Typhon launcher not work out?

Correct. They have apparently abandoned the TT in favour of the NSM as an interim measure.

 

[Forest Green]

October 2: second thoughts on Tomahawks for Ukraine

Trump unlikely to send Tomahawk long-range missiles to Ukraine, Reuters reports

Washington is more likely to provide shorter-range systems or let European allies buy long-range weapons for Ukraine, officials told Reuters.

kyivindependent.com

https://www.reuters.com/business/aerospace-defense/us-tomahawk-missile-shipments-ukraine-unlikely-sources-say-2025-10-02/

https://www.secretprojects.co.uk/threads/tactical-tomahawk.23784/post-839381

https://twitter.com/x/status/1976690487151988879

View: https://x.com/NOELreports/status/1976690487151988879

The main problem with supplying Tomahawks to Ukraine is the lack of a suitable mobile land-launcher.

Possibly there are still some of these around. Given how we've seen Storm Shadows, JDAMs and AASMs shoe-horned onto Su-24/27s and MiG-29s, workarounds to problems come faster than one would think. It's not like a regular military development schedule where everything takes a decade of tea and biscuits.

USMC's Tomahawk Cruise Missile Launching Drone Truck Eyed By Army

The Army is already fielding its own launchers to fire Tomahawk and SM-6 missiles, but they are much larger and more difficult to deploy.

www.twz.com

 

[Josh_TN]

Didn't the field tests with the Mk-70 Mod 0 Typhon launcher not work out?

That is a U.S. army effort, and while the system does work and will be rolled out with the various multi domain task forces es (I think five in all planned), the relative lack of mobility of the system was found to complicate its deployment.

 

[Forest Green]

https://news.usni.org/2023/07/25/marines-activate-first-tomahawk-battery

 

[Shoes31]

https://news.usni.org/2023/07/25/marines-activate-first-tomahawk-battery

That's from 2023, this year the Marines decided to terminate that program. I believe the Army is testing those same launchers as it offers a smaller footprint than the trailer based Mk-70 Typhon launchers.

If Ukraine does receive Tomahawks the canceled Marines JLTV based launchers would make a great firing platform for them.

U.S. Marine Corps Abandons Tomahawk Missiles, Doubles Down on Extended Range NMESIS in FY2026 Budget - Naval News

The U.S. Marine Corps' Long Range Fires launcher, built around a single-cell Mark 41 VLS cell for Tomahawk missiles has been cancelled

www.navalnews.com

 

[kqcke for you]

That's from 2023, this year the Marines decided to terminate that program. I believe the Army is testing those same launchers as it offers a smaller footprint than the trailer based Mk-70 Typhon launchers.

If Ukraine does receive Tomahawks the canceled Marines JLTV based launchers would make a great firing platform for them.

U.S. Marine Corps Abandons Tomahawk Missiles, Doubles Down on Extended Range NMESIS in FY2026 Budget - Naval News

The U.S. Marine Corps' Long Range Fires launcher, built around a single-cell Mark 41 VLS cell for Tomahawk missiles has been cancelled

www.navalnews.com

Those few will be atleast until 2026 in US Army inventory for an test fire

 

[Josh_TN]

I would presume mk70 would be used, if such a sale ever came to pass. I am still doubtful; the U.S. has low production rates and already has a large order for Japan on top of the blk5 upgrade kits.

 

[Titus K]

Fot the Netherlands aswell ... ~160 tomahawk blk V from 2028 onwards i believe

 

[bobbymike]

Hwasong-20: North Korea's New Solid-Fueled ICBM Has Arrived

North Korea just unveiled its new Hwasong-20 solid-fuel ICBM. A first look at the "most powerful" nuclear weapon that Kim Jong Un claims can reach the U.S.

nationalsecurityjournal.org

Someone can build a new ICBM.

 

[Forest Green]

https://twitter.com/x/status/1980980487226040484

View: https://x.com/UKikaski/status/1980980487226040484

 

[Flyaway]

The Yars launch was part of a major nuclear forces drill supervised by Putin. It also included the launch of a Sineva ballistic missile from the Barents Sea and firings of cruise missiles from Tu-95MS long-range bombers.

Here's video of the exercise, including some rarely seen footage of Yars inside its shelter just before launch.

View: https://www.youtube.com/watch?v=Oi69ymUMyxI


The Plesetsk authorities' reference to a "space rocket" prior to launch may well have been a deliberate attempt to cover up the upcoming nuclear exercise. See my recent posts over in the Russian space thread.

 

[Grey Havoc]

Foreign Hackers Breached a US Nuclear Weapons Plant Via SharePoint Flaws - Slashdot

Foreign hackers breached the National Nuclear Security Administration's Kansas City National Security Campus (KCNSC) by exploiting unpatched Microsoft SharePoint vulnerabilities. The intrusion happened in August and is possibly linked to either Chinese state actors or Russian cybercriminals. CSO...

it.slashdot.org

 

[Titus K]

The M51.3 SLBM entered active service this week

https://lemarin.ouest-france.fr/defense/nouvelles-tetes-nucleaires-oceaniques-plus-performants-le-missile-mer-sol-m51-mis-en-service-4547d0ee-b3e0-11f0-b69a-6e4ddcc8cd29

 

[NMaude]

Not a current nuclear weapon development but Scott Manley has just uploaded a video concerning the Daemon Core:

It started with a scene in a Mission Impossible movie, and ended up with a bunch of custom neutron simulations. There are a lot of meme's about the demon core and it's criticality accidents, but I decided to actually simulate how dangerous it would be to play games with the pits as a ball.​

The simulation work was performed using OpenMC, I'm a complete newbie to this, so don't trust your life with my results, please don't go bowling with nuclear pits unless you have a camera crew nearby, but not so nearby that they'd exceed safe radiation doses.https://openmc.org/https://www.youtube.com/redirect?event=video_description&redir_token=QUFFLUhqbW5PemJKZkFMRVliRWdjMnFqVkpudHA0eVdKUXxBQ3Jtc0tsQUlhaW1IOFZTWXBDYWRESkM1MTN4dldYMlp2SWR6bVJlN1huaS13SGIzOVQ1MEZTRnJZdGxZdGdtc01hMGFyTVY1MU0zS05lSWdPZG56dHhMZzFFSExCam1iUmJOb3dlc3Ixbll6WXc2NENnSzJhRQ&q=https://openmc.org/&v=6xsL6E-bQqQ​

Gavin's code for the case simulation is here, it's useful for getting started:https://gist.github.com/gridley/bb8c0...

 

[BonPlan2]

The limit isn't actually the submarine here, it's the submarine infrastructure, primarily dry docks and piers. They were all designed to accommodate boats up to the size of the Ohio class, which is 560 feet long. Anything significantly larger than that simply wouldn't fit into existing facilities.

The 16 tube Columbia class is 560 feet long, exactly the same length as the 24 tube Ohio class. The new electric drive basically eats up 8 missile tubes worth of space.

Larger variants of the Columbia class were studied during design work for the class. From a purely economic perspective, a 24 tube (or even larger) submarine would be ideal, especially coupled with the higher availability of the Columbia class – you could build and operate far fewer boats.

But there are a bunch of downsides to doing that as well, even more so given the decision to attempt to significantly downsize the submarine force while simultaneously shifting to a platform with much higher availability (which translates to fewer total boats required in order to keep the same number of boats continuously at sea).

I really don't think the choice to downsize to 16 tubes was a mistake. It made considerable sense to go with 16 tubes, especially so at the time in the environment that decision was made in. I think the choice to limit initial procurement to only 12 boats was the only real mistake.

But even that decision is arguably not that terrible, given that they can and likely will end up ordering additional boats.

It also likely wasn't politically feasible at the time to increase initial procurement beyond 12 given the way they planned the design requirements (a hellish compromise between economics, defense needs, nuclear arms reduction treaty demands, and over-optimistic predictions of continued reductions in nuclear weapons from future nuclear arms reduction treaties).

I'd imagine the fact that the current D5 missiles seem to be fairly heavily offloaded in order to meet treaty obligations also played a role as well. If you're expecting further follow-on treaties after New START to continue along the same trajectory, then why build for a fleet the same size as the current one? Even if you need to maintain the capability to upload missiles in an emergency, you don't necessarily need as much upload margin as we currently have available, especially in a future environment of the kind that was predicted at the time, where future arms control treaties would have even more severely cut down on the maximum numbers of warheads and launchers.

The sudden outbreak of full-scale war in Ukraine, near total disintegration of New START with no replacement on the horizon, and China's unexpectedly aggressive nuclear buildup (among many other recent major geopolitical issues) have dramatically changed the nuclear threat environment almost beyond recognition in a very short time period. I don't blame the designers for failing to predict all of this.

Here's a highly relevant article that covers most of the issues relevant to the Columbia class design choices: https://www.realcleardefense.com/ar...out_redesigning_the_columbia_ssbn_824714.html

how many warheads per missile in the future D5 ?
16 of these new variat D5 missile may be the same than 24 legacy D5, no?

 

[Forest Green]

View: https://www.youtube.com/watch?v=-XNcHra4hbU&pp=ugUEEgJlbg%3D%3D

 

[Grey Havoc]

The phrase, 'whistling though the graveyard' occurs to me here. Along with famous last words such as 'They couldn't hit an elephant at this distance'.

 

[Scott Kenny]

how many warheads per missile in the future D5 ?
16 of these new variat D5 missile may be the same than 24 legacy D5, no?

As I understand it from public discussion, 1-8x W76s, 4x W88s.

There's going to be a couple of birds per sub with the tiny yield W76Mod2 (5-7kt, sub-Hiroshima) warheads for escalate-to-descalate, and those are almost certainly 1 warhead per missile with every single penaid the US has developed installed for balance if nothing else. If you can stuff a W76Mod2 physics package into some fancy maneuverable RV, it'll probably have that, too, less for accuracy and more for making interception harder. The mission calls for only launching one of those, the second missile is a spare carried in case there's a fault with either the missile or the tube.

Side note: I just looked at the Pershing II, and that MARV is crazy heavy compared to the W88/Mk5 MIRV. The whole Pershing II MARV package is nearly 1500lbs! It is also about 14ft long, which I am pretty sure is nearly twice the length of the Mk5 RBA.​

There were only 400 total W88s (~475kt) made. So that gives you 32x W88s per Columbia-class (Okay, technically 33 1/3 W88s per sub, but I rounded. This would leave you with 16x leftover W88s to spread wherever or save for rotation). If you load them as 4 per bird that gives you 8 birds per boat as your heavy hitters, half your load.

That leaves 6 birds with some number of W76Mod1s (90-100kt) each, likely 8 per bird but fewer is possible.

Interestingly, the W88 in Mk5 RBA weighs twice as much as W76 in Mk4 RBA, so the missiles would have the same range if loaded that way. IIRC the W76Mod2 was intended for depressed trajectories, so losing a lot of range despite the low payload weight.

 

[Justo Miranda]

View: https://www.youtube.com/watch?v=-XNcHra4hbU&pp=ugUEEgJlbg%3D%3D

It has been many years since the nuclear threat worked at Suez

Project Pluto

Project Pluto

www.fourmilab.ch

 

[Forest Green]

As I understand it from public discussion, 1-8x W76s, 4x W88s.

There's going to be a couple of birds per sub with the tiny yield W76Mod2 (5-7kt, sub-Hiroshima) warheads for escalate-to-descalate, and those are almost certainly 1 warhead per missile with every single penaid the US has developed installed for balance if nothing else. If you can stuff a W76Mod2 physics package into some fancy maneuverable RV, it'll probably have that, too, less for accuracy and more for making interception harder. The mission calls for only launching one of those, the second missile is a spare carried in case there's a fault with either the missile or the tube.

Side note: I just looked at the Pershing II, and that MARV is crazy heavy compared to the W88/Mk5 MIRV. The whole Pershing II MARV package is nearly 1500lbs! It is also about 14ft long, which I am pretty sure is nearly twice the length of the Mk5 RBA.​

There were only 400 total W88s (~475kt) made. So that gives you 32x W88s per Columbia-class (Okay, technically 33 1/3 W88s per sub, but I rounded. This would leave you with 16x leftover W88s to spread wherever or save for rotation). If you load them as 4 per bird that gives you 8 birds per boat as your heavy hitters, half your load.

That leaves 6 birds with some number of W76Mod1s (90-100kt) each, likely 8 per bird but fewer is possible.

Interestingly, the W88 in Mk5 RBA weighs twice as much as W76 in Mk4 RBA, so the missiles would have the same range if loaded that way. IIRC the W76Mod2 was intended for depressed trajectories, so losing a lot of range despite the low payload weight.

As I understand it, both the W76 and W88 are to be replaced by the W93 (or Astraea A21 for the UK)using the Mk7 RB, which is estimated to be 250-350kT and probably closer to W76 weight-wise, using the W76 secondary and a new IHE primary. Given recent tests there's a possibility each RB will be a HGV.

In other news:

France updates submarine-launched nuclear missile amid arms race

The third and latest version of the M51 has new nuclear warheads as well as improved range, accuracy and capability to penetrate enemy defenses.

www.defensenews.com

The M51.3 is estimated to have a range of more than 9,500 kilometers, compared to more than 9,000 kilometers for the previous iteration, according to the Bulletin of the Atomic Scientists.

The first version of the M51 ballistic missile became operational in 2010, and the DGA in August tasked ArianeGroup with development of the future M51.4 version.

As well as updating the ocean-based nuclear-deterrence component, France is working on the air-launched ASN4G hypersonic missile to replace the ASMPA nuclear cruise missile carried by the Rafale fighter jet. The new missile is to be integrated on the future F5 standard of the Rafale.

 

[BonPlan2]

I just looked at the Pershing II, and that MARV is crazy heavy compared to the W88/Mk5 MIRV. The whole Pershing II MARV package is nearly 1500lbs! It is also about 14ft long, which I am pretty sure is nearly twice the length of the Mk5 RBA.

Yes but Pershing 2 warhead was not a "classical" MARV as it was fitted with a nose radar so as to increase precision.
A classical MARV is not fitted with a final course seeker (as far as I know).

 

[BonPlan2]

As I understand it, both the W76 and W88 are to be replaced by the W93 (or Astraea A21 for the UK)using the Mk7 RB, which is estimated to be 250-350kT and probably closer to W76 weight-wise, using the W76 secondary and a new IHE primary. Given recent tests there's a possibility each RB will be a HGV.

In other news:


View attachment 789845

Interesting to compare the lower french yield on M51 with the US and GB ones.
M51is supposed to carry up to 10 warheads, with a classical layout of 6.

I never understood why the ASMPA, made for a 'ultime message' is a 300kt yied and the warheads of subs only 100kt.... Why not the contrary? Why not a small warhead on ASMPA (15kt) ?

 

[Josh_TN]

how many warheads per missile in the future D5 ?
16 of these new variat D5 missile may be the same than 24 legacy D5, no?

I do not know if it’s firmly established what current D5s can carry. Eight is number most often given but there have been some allegations/rumors of a dozen (presumably limited to smaller and lighter W76 if true).

 

[Forest Green]

Side note: I just looked at the Pershing II, and that MARV is crazy heavy compared to the W88/Mk5 MIRV. The whole Pershing II MARV package is nearly 1500lbs! It is also about 14ft long, which I am pretty sure is nearly twice the length of the Mk5 RBA.

1970s electronics, remember how large mobile phones used to be? Or just think about the AIM-120A, which was a decade later and how much AMRAAM range has improved since then, much of that due to reduced electronics size and mass.

Interesting to compare the lower french yield on M51 with the US and GB ones.
M51is supposed to carry up to 10 warheads, with a classical layout of 6.

I never understood why the ASMPA, made for a 'ultime message' is a 300kt yied and the warheads of subs only 100kt.... Why not the contrary? Why not a small warhead on ASMPA (15kt) ?

TNO and TNO.2 yield is a guess made by outsiders TBH, the actual yield is classified, there are some indications it could be 300kT also, e.g. in some places it says it's based on the ASMP-A warhead.

 

[Forest Green]

I do not know if it’s firmly established what current D5s can carry. Eight is number most often given but there have been some allegations/rumors of a dozen (presumably limited to smaller and lighter W76 if true).

8 W88s, 12 W76s. 11,500km with 4 W88s (700kg total), 7600km with 8 W76s (1400kg total). W76s were 95kg each estimated., so 12 would be 1140kg, giving just over 9,000km probably.