SSN (X) - Seawolf Redux or something far larger?

"Run Silent, run deep" is supposed to be the US Navy's submariner motto…. instead of designs -from within the US submarine community- that featured spherical pressure hulls and 4000+ ft diving depths, and continues today with the SSN(X). Diving depth is more valuable than stealth. Period.
Something like what we saw here?


Tough
 
Last edited:
Diving depth is more valuable than stealth. Period.

Why?

Aside from seabed ops, all the interesting stuff seem to be happening at the surface. And seabed ops are better handled by ROVs and the like. I can't see any reason to run large, manned subs very deep. It seems like a recipe for finding yet more mis-charted underwater terrain.
As part of the studies for SSN0Z, AUWE recommended diving depths of 2000-4000ft to take advantage deep sound channels to take advantage of Reliable Acoustic Path, to protect against Magnetic Anomaly Detection, exploit shadow zones under all existing surface ducts, and to aid the evasion of torpedoes with internal-combustion engines, which would lose power with depth due to the exhaust back-pressure.
That was their recommendation in 1969-80... 40-50 years ago.

When the design studies were resumed in 1982, the sub size had dropped from 6,500-7,300 tons submerged (costing above 138% of a Trafalgar) to 5,000 tons maximum as an improved Trafalgar (~110% cost).

Much has changed in undersea warfare since the "deep dive design" was in favor with the Admiralty.
 
As part of the studies for SSN0Z, AUWE recommended diving depths of 2000-4000ft to take advantage deep sound channels to take advantage of Reliable Acoustic Path, to protect against Magnetic Anomaly Detection, exploit shadow zones under all existing surface ducts, and to aid the evasion of torpedoes with internal-combustion engines, which would lose power with depth due to the exhaust back-pressure.
That was their recommendation in 1969-80... 40-50 years ago.

When the design studies were resumed in 1982, the sub size had dropped from 6,500-7,300 tons submerged (costing above 138% of a Trafalgar) to 5,000 tons maximum as an improved Trafalgar (~110% cost).

Much has changed in undersea warfare since the "deep dive design" was in favor with the Admiralty.
Future SSN was very deliberately cost-constrained to an extent that SSN0Z wasn't. SSN20 (which succeeded SSN0Z and Future SSN) may have been much closer to SSN0Z in concept, as design studies for both have not been declassified, whilst those for cheaper Future SSN have.

Of course a submarine optimised for a war with China may not have much of an opportunity to make use of such a diving depth, especially given the size of the East China Sea and South China Sea Continental Shelves.

Do we know what the current state of underwater communications and data-links is? The UK had a requirement for an underwater data-link to use with the computerised command systems of their submarines, and I imagine something like that is now well within the realms of technical plausibility.
 
Do we know what the current state of underwater communications and data-links is? The UK had a requirement for an underwater data-link to use with the computerised command systems of their submarines, and I imagine something like that is now well within the realms of technical plausibility.


There are definitely experiments with underwater acoustic modems that were pretty successful. They basically used a network similar to an internet IP addressing. SPAWAR did a lot of field tests in the early oughts with a system they referred to as "Seaweb" at the time. This network at its most basic form were buoys that acted as repeaters across a wide area (per the IP address model). Some of the other nodes of the area network were sensors attached to acoustic modems that listened for ships or tracked ocean currents. Other nodes were mobile, including UUV gliders and SSNs on occasion (IIRC specifically USS Ashville in one experiment circa 2004). Most every experiment included a radio buoy gateway with an acoustic modem and satellite radio that connected the entire undersea network to shore (Iridium sat phone connections were used for these experiments). In at least one experiment the glider sea node also doubled as the radio gateway, offloading its stored data via satphone on its upswings near the surface then diving back down for its forward motion.

In theory this would allow a boat to transmit information via the local network which would eventually (much slower propagation of data via sound in water and vastly lower bandwidth) go to shore via satellite, though this was not the core goal of the experiment. The information regarding this research seemed to go dark over a decade ago; here are some old references to it:





More recently a more permanent system is reportedly to be established called "fishhook", which seems to be a modern incarnation of SOSUS with more modern sensor nodes and acoustic modems. I suspect some of these nodes also aren't explicitly tied to shore by cable; the USN was experimenting with wave/current powered buoys decades ago and its likely part of any Pacific underwater network includes stand alone sensor packs powered by wave action.



Additionally budget documents regarding the USN Clandestinely Deployed Mine program (which should have entered IOC by now) indicate Incr 1 will be fairly standard mines, but that Inc 2 will have the ability to activated or deactivated remotely - presumably by acoustic modem signal. Cutaways of the future "Hammerhead" CAPTOR mine also include a communications assembly. So it looks like modern mine fields and sensor fields will merge into a field of sensors and effectors interspersed across a larger number of acoustic modem repeaters.



All of this is of course with a fair amount of conjecture and assumptions, because those who know don't say. But reading the bread crumbs, it looks like the USN has an underwater communications systems and sensor network pre deployed in some choke points in the Pacific not unlike the old SOSUS network, as well as an ability to add semi persistent buoys and seabed sensors to augment coverage or build new networks in other areas (compromising these devices is probably a big concern of thier deployment). In the near future is seems likely that mine fields will be collocated with the sensor field (or vice versa) or that indeed the mines will be the sensors, with optional lethality. Additionally the sensor field might extend the engagement range of mines/effectors in the case of mobile effectors (e.g. Hammerhead mk54). SSNs likely will be able to communicate with and through such a network, though one thing to keep in mind again is that speeds and bandwidths are very low - these sensors rely on in buoy processing to generate data; transmitting raw data to shore is not realistically possible unless there is a direct cable connection from sensor to shore.
 
Last edited:
Of course a submarine optimised for a war with China may not have much of an opportunity to make use of such a diving depth, especially given the size of the East China Sea and South China Sea Continental Shelves.


I think it would be a little fool hardy to plan for the future SSNs to only operate in one environment against one opponent, particularly over the kind of time frames we are discussing now. But the argument for deep depth against combustion engine torpedoes is long dead, and the argument for sound channels does beg the question, where exactly are you expecting these boats to fight? Most naval conflict takes place near land; the fact that the US was going to have to reinforce Europe was a rather unique situation that called for complete control of the open water of the north Atlantic. It's possible China eventually produces a similar problem in the Pacific but not very probably, IMO.
 
the fact that the US was going to have to reinforce Europe was a rather unique situation that called for complete control of the open water of the north Atlantic.

And, ironically, it looks as though the Soviets might not have actually been planning for that battle. Seems like most of their sub force (at least through the early 1980s) was aimed to preserve the bastions in the Norwegian Sea north of the GIUK Gap (and in the Sea of Okhtosk in the Pacific) not in the mid-Atlantic. Assuming this strategy was actually is implemented in wartime, the focus of the USN and NATO navies on refighting the Battle of the Atlantic may have been incredibly misguided.

Hat tip to @RP1 for linking to this brief last month.


The whole thread she started here is very illuminating, with some great links:

View: https://twitter.com/R_P_one/status/1617180155427913728
 
After the United States launches a nuclear strike against the USSR, a counter-strike against NATO countries follows. Only this way, not the other way around. After that, there are two weeks for a "Dash to the English Channel", to reach the Atlantic coast of Europe. The goal is to prevent the American expeditionary forces from landing. Hunter submarines are the first line of defense in the Atlantic. Their task is to meet the US Navy

18-3070219-b-138.jpg
 
Exactly how the Soviet SSN/SSGN force would be used likely would be conditional. The threat could hardly be ignored. But it has come to light that defense of SSBNs, and Soviet waters and approaches, were much higher priorities. That said, from one item I recall reading part of the reason for that logic was that a relatively small number of nuclear submarines could threaten a fairly vast amount of ocean. Were those subs to be initially unsuccessful or the amount of interdiction inadequate, once could easily see more boats being contributed to the effort. Or perhaps pre war doctrine is completely ignored and a surge to the north Atlantic occurs initially; who can say.
 
Exactly how the Soviet SSN/SSGN force would be used likely would be conditional. The threat could hardly be ignored. But it has come to light that defense of SSBNs, and Soviet waters and approaches, were much higher priorities. That said, from one item I recall reading part of the reason for that logic was that a relatively small number of nuclear submarines could threaten a fairly vast amount of ocean. Were those subs to be initially unsuccessful or the amount of interdiction inadequate, once could easily see more boats being contributed to the effort. Or perhaps pre war doctrine is completely ignored and a surge to the north Atlantic occurs initially; who can say.

Sure, plans can change. And if things had not gone well, Gorshkov might have found himself out fairly quickly.

But unless they had prepared for a large submarine surge into the North Atlantic, would they have been capable of actually pivoting on the fly? In particular, would they have had the ISR apparatus in place to actual cue subs onto targets in the North Atlantic?
 
Exactly how the Soviet SSN/SSGN force would be used likely would be conditional. The threat could hardly be ignored. But it has come to light that defense of SSBNs, and Soviet waters and approaches, were much higher priorities. That said, from one item I recall reading part of the reason for that logic was that a relatively small number of nuclear submarines could threaten a fairly vast amount of ocean. Were those subs to be initially unsuccessful or the amount of interdiction inadequate, once could easily see more boats being contributed to the effort. Or perhaps pre war doctrine is completely ignored and a surge to the north Atlantic occurs initially; who can say.

Sure, plans can change. And if things had not gone well, Gorshkov might have found himself out fairly quickly.

But unless they had prepared for a large submarine surge into the North Atlantic, would they have been capable of actually pivoting on the fly? In particular, would they have had the ISR apparatus in place to actual cue subs onto targets in the North Atlantic?

Presumably the AV-MF could provide whatever intelligence they were already generating for their bomber operations. There were also the RORSAT series and the associated ESM satellite systems. Reallocating the D/E boats wasn't going to be that realistic or practical, but retasking nuke boats doesn't seem like it would take much effort or forethought.
 
"Run Silent, run deep" is supposed to be the US Navy's submariner motto…. instead of designs -from within the US submarine community- that featured spherical pressure hulls and 4000+ ft diving depths, and continues today with the SSN(X). Diving depth is more valuable than stealth. Period.
Something like what we saw here?

Losharik nude.
 
"Run Silent, run deep" is supposed to be the US Navy's submariner motto…. instead of designs -from within the US submarine community- that featured spherical pressure hulls and 4000+ ft diving depths, and continues today with the SSN(X). Diving depth is more valuable than stealth. Period.
Something like what we saw here?

Losharik nude.
True that!
Still, look at the K-278 Komsomolets. With a test depth of 3300 ft and a do not exceed depth of 4250 ft, it was and is invulnerable to any existing torpedo. I'd take that capability over stealth anytime, especially as you can sit with impunity at 3300 ft and bang away with your active sonar. Better yet, combine depth and stealth. Another thing is that because the ship's hull is so strong that if you are at shallower depths and get a near or direct hit by a torpedo you would have a much better chance of surviving. The double hull construction also enables more freedom in hydrodynamic design- so faster speeds for the same power and MUCH greater reserve buoyancy. Its win-win-win. Single hull designs are almost inexcusable from a safety perspective alone.
 
The future AUKUS MIC moving towards very close integration on pretty much everything including defense industrial capacity?

Ps I don’t use MIC as a pejorative :)
 

From Naval Institue News​

NORTHCOM: Russia Close to Persistent Nuclear Cruise Missile Attack Sub Presence off U.S. Coasts​


1159323.jpg


Russia could have its most powerful and quiet nuclear attack submarines on persistent patrols off either U.S. Coast in the next two years, the head of U.S. Northern Command told the Senate Armed Services Committee on Thursday.

In response to questions from Sen. Joni Ernst (R-Iowa) on the threat of Chinese and Russian cruise missile submarines operating close to the U.S., NORTHCOM commander Gen. Glen VanHerck said that the deployments of the Russian Yasen-class nuclear cruise missile attack boats have been deploying more frequently.

“[The risk is] absolutely increasing. Within the last year, Russia has also placed their [Yasens] in the Pacific,” he said. “Now not only the Atlantic, but we also have them in the Pacific and it’s just a matter of time – probably a year or two – before that’s a persistent threat, 24 hours a day. … That impact has reduced decision space for a national senior leader in a time of crisis.”

Also known by their NATO reporting name Severodvinsk class, the 13,800-ton Yasen-class attack boats are among the most capable submarines in the world. In particular, the three current boats in the class are capable of a special quiet operations mode that make them difficult to detect in the open ocean. In 2018, the lead boat in the class, Severodvinsk, evaded U.S. efforts to find it for weeks, according to press reports.

Navy officials have told USNI News that the service has become increasingly concerned with the efficacy of the Russian submarine force. The growing ability of Russian submarines to operate undetected in the Atlantic pushed the Navy to reactivate U.S. 2nd Fleet and create a command for anti-submarine warfare across the Atlantic in 2018. The Russian Navy has planned to build ten Yasen-class attack boats, with the fourth to commission later this year, according to Russian press reports.

The Russians have also recently delivered two new strategic nuclear submarines. In January, the Russian Navy commissioned the 24,000-ton Borey-class nuclear ballistic missile submarine Generalissimus Suvorov. In July, the Russian Navy delivered Belgorod – a strategic weapons platform fitted with school bus sized nuclear torpedoes that can be fitted with a 100-megaton nuclear warhead.

VanHerck also emphasized the need for the U.S. to expand its operations in the Arctic, as Russia has modernized its assets in the region and China continues to push farther north. “Russia has modernized their fleet of icebreakers. They’ve modernized their strategic defense along with their submarine forces. China is sailing into the Arctic under the guise of research [missions] and we know they’re doing military operations, surveying the seabed.”

VanHerck said the U.S. is short of assets in the Arctic as Russia and China continue to expand operations.
“We’re not organized, trained and equipped to operate and respond in the Arctic. Infrastructure is a big concern for me, whether that be runway links, whether that be buildings, whether that be weapons storage, whether that be fuel storage,” he said. “We need persistence that requires icebreakers. We as a nation are in bad shape regarding icebreakers, and I fully support the Coast Guard’s plan. We need to go faster.”
 
Apparently, this was shown at the Sea Air and Space Conference in January 2023, and has been making the rounds ever since. Some things of note:

- The hull appears to resemble that of traditional USN submarines, although the bow is sharper. Compare that to the original Seawolf concepts for example, which were much fatter, almost resembling Soviet SSNs. I assume the new bow offers better hydrodynamic or acoustic performance, or something in that regard.
- Note the new sail style, I have no idea what is going on there. Maybe they’re trying to install a bunch of new sensors there?
- Standard pumpjet, X-planes, and the fairwater planes are mounted on the bow, rather than the sail. None of that is of particular surprise.
- What is normally 3 small WAA flank arrays per side have been combined into 2 massive Large Vertical Arrays (apparently these will also go in the Block V 774s).
- It sticks to the peripheral bow-mounted tubes, but there are six of them. This would place the tube count between that of the 774 and Seawolf. Note the last USN sub to have the 6-tube configuration was the old Skipjacks. This also probably makes 2 torpedo tube decks.
- The image shows 12, single-use, external torpedo tubes mounted on the outside of the hull. They are divided between 3 separate groups, with 4 tubes per group. You can presumably strap mines, UUVs, CATs, and additional torpedoes inside of these. There are 24 tubes in total.
- Apparent lack of VLS and VPMs, I assume this means any TLAMs will fired via the traditional torpedo tubes, as the external tubes can make up for any loss in payload.

Discuss.

Source:
View: https://m.youtube.com/watch?t=445&v=fTLFLcu8Lzo&feature=youtu.be
Image at 7:25
 

Attachments

  • SSN(X).jpg
    SSN(X).jpg
    35.8 KB · Views: 189
Last edited:
Apparently, this was shown at the Sea Air and Space Conference earlier this year, and has been making the rounds ever since. Some things of note:

Discuss.
The External Tubes/Weapons Clips? definitely remind me of the Forward PASS and Team 2020 SSN designs (although those designs also had VLS).

Certainly not as adventurous as those designs when it comes to UUV deployment, doesn't look like there are large free-flooding areas containing UUV Hangars, or other designs drawn up around the same time, with the UUVs carried conformally (unless you could replace the external torpedo tube blocks?).

I am assuming the big side arrays are the Large Vertical Arrays that were initially planned to be fitted on South Dakota (SSN-790).
 
Last edited:
Apparently, this was shown at the Sea Air and Space Conference earlier this year, and has been making the rounds ever since. Some things of note:

Discuss.
The External Tubes/Weapons Clips? definitely remind me of the Forward Pass and Team 2020 SSN designs (although those designs also had VLS).

Certainly not as adventurous as those designs when it comes to UUV deployment, doesn't look like there are large free-flooding areas containing UUV Hangars, or other designs drawn up around the same time, with the UUVs carried conformally (unless you could replace the external torpedo tube blocks?).

I am assuming the big side arrays are the Late Vertical Arrays that were initially planned to be fitted on South Dakota (SSN-790).
UUVs are speculative in my part, sorry, should’ve specified that.

What’s Forward Pass and Team 2020 SSN? I’m not familiar with either.
 
What are the advantages of these externally mounted torpedo tubes?
 
Well single one time volley size would be much larger. Can’t think of any situation that would call for that outside engaging a large surface task force.
 
What are the advantages of these externally mounted torpedo tubes?
Increase the effective payload without having to increase the size of the weapons room inside the pressure hull. Also means the crewed area can focus on recoverable systems/UUVs, with the single-use weapons sitting happily outside until go-time.
 
Apparently, this was shown at the Sea Air and Space Conference earlier this year, and has been making the rounds ever since. Some things of note:

Discuss.
The External Tubes/Weapons Clips? definitely remind me of the Forward Pass and Team 2020 SSN designs (although those designs also had VLS).

Certainly not as adventurous as those designs when it comes to UUV deployment, doesn't look like there are large free-flooding areas containing UUV Hangars, or other designs drawn up around the same time, with the UUVs carried conformally (unless you could replace the external torpedo tube blocks?).

I am assuming the big side arrays are the Late Vertical Arrays that were initially planned to be fitted on South Dakota (SSN-790).
UUVs are speculative in my part, sorry, should’ve specified that.

What’s Forward Pass and Team 2020 SSN? I’m not familiar with either.
 
Apparently, this was shown at the Sea Air and Space Conference in January 2023, and has been making the rounds ever since. Some things of note:

- The hull appears to resemble that of traditional USN submarines, although the bow is sharper. Compare that to the original Seawolf concepts for example, which were much fatter, almost resembling Soviet SSNs. I assume the new bow offers better hydrodynamic or acoustic performance, or something in that regard.
- Note the new sail style, I have no idea what is going on there. Maybe they’re trying to install a bunch of new sensors there?
- Standard pumpjet, X-planes, and the fairwater planes are mounted on the bow, rather than the sail. None of that is of particular surprise.
- What is normally 3 small WAA flank arrays per side have been combined into 2 massive Large Vertical Arrays (apparently these will also go in the Block V 774s).
- It sticks to the peripheral bow-mounted tubes, but there are six of them. This would place the tube count between that of the 774 and Seawolf. Note the last USN sub to have the 6-tube configuration was the old Skipjacks. This also probably makes 2 torpedo tube decks.
- The image shows 12, single-use, external torpedo tubes mounted on the outside of the hull. They are divided between 3 separate groups, with 4 tubes per group. You can presumably strap mines, UUVs, CATs, and additional torpedoes inside of these. There are 24 tubes in total.
- Apparent lack of VLS and VPMs, I assume this means any TLAMs will fired via the traditional torpedo tubes, as the external tubes can make up for any loss in payload.

Discuss.

Source:
View: https://m.youtube.com/watch?t=445&v=fTLFLcu8Lzo&feature=youtu.be
Image at 7:25
The image is notional, not a road map. Notably, the location of the external weapon clips is problematic. Flow noise will get bad at high speed, and a tugboat could hit them. There's also more mundane questions like: How do you reload them? They're below the waterline, so either the whole pod as to be taken off and payload swapped on shore or some kind of cofferdam has to be put along the hull to make reloading possible. If they were on the upper surface of the hull which remains above the waterline, reloading wouldn't be a problem.
 
The raked sail is similar to concept art for the British SSN(R). I'd assume there's a common impetus, whether it's some hydrodynamic tweak or something else.
 
The Russians use external tubes on some of the Akula class for the barrier system, but as mentioned they are on the upper surface of the bow. I don’t see how any other location works.
 
Compared to
What are the advantages of these externally mounted torpedo tubes?
Compared to internal tubes, not many advantages. The advantage of the external tubes is simply you can carry more weapons without taking away from internal stores.
Edit: Internal net internet
 
Last edited:
Apparently, this was shown at the Sea Air and Space Conference earlier this year, and has been making the rounds ever since. Some things of note:

Discuss.
The External Tubes/Weapons Clips? definitely remind me of the Forward Pass and Team 2020 SSN designs (although those designs also had VLS).

Certainly not as adventurous as those designs when it comes to UUV deployment, doesn't look like there are large free-flooding areas containing UUV Hangars, or other designs drawn up around the same time, with the UUVs carried conformally (unless you could replace the external torpedo tube blocks?).

I am assuming the big side arrays are the Late Vertical Arrays that were initially planned to be fitted on South Dakota (SSN-790).
UUVs are speculative in my part, sorry, should’ve specified that.

What’s Forward Pass and Team 2020 SSN? I’m not familiar with either.
This is great, thank you!
 
the fact that the US was going to have to reinforce Europe was a rather unique situation that called for complete control of the open water of the north Atlantic.

And, ironically, it looks as though the Soviets might not have actually been planning for that battle. Seems like most of their sub force (at least through the early 1980s) was aimed to preserve the bastions in the Norwegian Sea north of the GIUK Gap (and in the Sea of Okhtosk in the Pacific) not in the mid-Atlantic. Assuming this strategy was actually is implemented in wartime, the focus of the USN and NATO navies on refighting the Battle of the Atlantic may have been incredibly misguided.

Hat tip to @RP1 for linking to this brief last month.


The whole thread she started here is very illuminating, with some great links:

View: https://twitter.com/R_P_one/status/1617180155427913728
I read some years ago that one of the biggest Soviet takeaways from WW2 regarding Naval Matters was the failure of the Japanese submarine service to prevent the US logistics train from extending to the Western Pacific. I gathered that this was seen as a major failure, especially in comparison to the German efforts in the Atlantic and was a mistake that the Soviet Navy was determined to learn from and not emulate.

While protecting the bastions was a high priority to be sure, I would strongly suspect that stopping the convoys was as well. This seems to influence the design of what NATO called he "Alphas" which seem designed to do hit and run attacks rather than poke about a SSBN bastion waiting to pounce.


(My degree's in History and my Coast Guard rate was in Marine Science, not ASW so I'm fully prepared to be corrected on this)
 
I think I read in the bad old days that convoy interdiction was a low priority partly because the Soviets reasoned that it wouldn’t take that many boats to be effective. Though that outlook probably predated the Walker spy effort.
 
This seems to influence the design of what NATO called he "Alphas" which seem designed to do hit and run attacks rather than poke about a SSBN bastion waiting to pounce.

The Alfas were actually sort of the epitome of the Soviet defensive ASW strategy. They were designed as interceptors to engage NATO attack subs (and missile subs, which never really materialized) in Soviet defensive zones. So, both bastions and the areas around Soviet fleet bases. But the Alfas would not be expected to push south of the GIUK gap.

It looks like the subs heading south would have been primarily the SSGNs and maybe some of the SSNs. But those forces seem to have had more focus on anti-carrier ops than convoy interdiction.
 
Another step in the evolution and progression to SSN(X)...Virginia Block IV and a Sea Bed Warfare Variant.

From Naval News:

US-Navy-Modified-Virginia-Class-Submarine-SSW.jpg

U.S. Navy To Get New Unique Submarine: Virginia SSW​

The USS Jimmy Carter is widely regarded as the most secretive submarine in the U.S. Navy. It is especially equipped for Seabed Warfare, unreported missions deep below the waves. Now a new seabed warfare submarine, using a Virginia Class hull, is planned.​

H I Sutton 20 Apr 2023

The USS Jimmy Carter is currently the U.S. Navy’s principal seabed warfare submarine, specially fitted for covert spy missions deep beneath the waves. Now plans are underway to build a follow on special spy submarine using the newer Virginia Class hull.

A single Mod VA SSW (Modified Virginia, Subsea and Seabed Warfare) version of the Virginia Class is expected to be built.

Work is already underway at the famous Electric Boat shipyard in Groton, Connecticut. A basic outline of the design was shared by General Dynamics Electric Boat’s President, Kevin Graney, in a January 2022 at a Connecticut Economic Summit in 2022. Since then some information about the SSW design has slowly emerged in open sources, but naturally the details remain cloaked. According to the Congressional Research Service, a single boat will be procured in the U.S. Navy’s 2024 budget. The calculated cost is $5.1 billion, almost a billion more than the baseline Virginia Class.

Seabed Warfare​

Seabed warfare has been brought into sharp focus by Russia’s ongoing efforts to map undersea infrastructure. And by the September 2022 with the attack on the Nord Stream gas pipelines in the Baltic. There is no suggestion that the USS Jimmy Carter was involved in the Nord Stream incident (it wasn’t!). But the attack shows the relevance of these capabilities. Most seabed warfare however is closer to espionage than sabotage. And the American submarines excel.

The history of operations against undersea infrastructure, such as sensor networks, communications and energy infrastructure goes back a long way. And both the U.S. Navy and Russian Navy have strong traditions.

In the 1970s Operation Ivy Bells saw the U.S. Navy tapping Soviet communications networks deep undersea. Tapping the cables which the Soviets thought were safe gave the U.S. valuable insight and intelligence. The first tap, in the Sea of Okhotsk was followed by several others of similar significance but less fame. The USSR only found out about them when a Soviet spy deep in the American intelligence apparatus, Ronald Pelton, betrayed them.

At first the U.S. Navy used a converted cruise missile submarine, USS Halibut. This was followed by USS Seawolf and then USS Parche, both of which were upgraded with extended hulls to carry the specialist equipment. Then in the 2000s one of the new Seawolf class submarines, USS Jimmy Carter, was built with the hull extension already fitted. This submarine becoming the premiere seabed warfare boat of the U.S. Navy. The new specialized Virginia class submarine will augment or succeed USS Jimmy Carter.

The Virginia SSW Submarine Design​

Extract details of the new Virginia SSW submarine are, as we should expect, unclear. Even the USS Jimmy Carter which has been in service almost 20 years remains something of a mystery. However we can expect the new submarine to carry specialist uncrewed underwater vehicles (UUVs), remote operated vehicles (ROVs) and special operations submersibles.

Some of the vertical launch systems for missiles, known as VPMs (Virginia Payload Modules) will be repurposed for new systems. Additionally the keel beneath them will be extended. Exactly how this will interface with specialist submersibles can only be speculated at.

Russia too has a long tradition of seabed warfare. And relative to even the U.S. Navy, is heavily invested in this area. The largest submarines in service anywhere in the world are Russia’s fleet of specialist submarines. The U.S. Navy’s seabed warfare capability is likely more sophisticated, but Russia’s is broader and more plentiful.

So if the U.S. Navy wishes to retain any advantage it has, it is natural that it would look to have a successor to the USS Jimmy Carter.


From Naval Institute News:

Navy New Virginia Block VI Virginia Attack Boat Will Inform SSN(X)​

By: Megan Eckstein

6392057-2.jpg


The submarine community is nearing a plan for its Block VI Virginia-class submarine, which will be an improvement in stealth and capability compared to the boats under construction today and will be a bridge to the upcoming SSN(X) program.

The Block V Virginia submarines – the first three of which have already begun construction – represent the first time the Navy has made a major investment in increasing the capability of this class of ship. Whereas past blocks have focused on construction and maintenance efficiencies, and incremental capabilities are added through software updates regularly, the Block V design adds 28 more missile tubes to greatly enhance the strike capability of these SSNs, Program Executive Officer for Submarines Rear Adm. David Goggins said this week at the Naval Submarine League annual symposium.

Block VI will continue that trend of adding new capability and lethality to the boats, which will be procured in a multiyear contract from Fiscal Years 2024 through 2028.

“Block VI will focus on building upon the acoustic superiority” technology that’s being built into and tested on the future South Dakota (SSN-790), as well as “really enable that organic subsea, seabed warfare kit release for the first time.”

Specifically, he said the Navy and industry are working on improved stealth to operate in a contested environment; enhanced sonar performance through a new bow conformal array; and the ability to sense and interact with more of the water column, including the sea bed.

Goggins said those ideas have been chosen as priorities for Block VI for two reasons: first, they’ll improve the capability of the Virginia class in the near term, and second, they’ll help prove out technologies that could influence the next-generation SSN(X) design.

“We’ll spend the next year evaluating the maturity and feasibility of these capabilities [on the slide he presented], followed by a downselect next year. And that will really allow us to mature the technology,” Goggins said.

Goggins’ slide also highlighted propulsors, improved payload and vehicle hosting, improved situational awareness and additional payloads as features of the Block VI design.

Elsewhere during the Sub League event, it was clear that the rest of the submarine force is eagerly eyeing the SSN(X) program and what kinds of improvements are within the realm of the possible for that program.

Vice Adm. Daryl Caudle, commander of Naval Submarine Forces and Submarine Force Atlantic, said during his presentation that SSN(X) could be based on the Virginia design, could be based on the Columbia-class ballistic missile submarine (SSBN-826) design, or could be a clean-sheet design.

“We’re going to get alternatives and make decisions on how to make this new SSN match what we need to stay ahead of our peers. This is definitely going to be increased speed: there’s no question that speed is basically important to improve every single joint warfare function. Speed is just so important – it plays out so well in all our wargaming, so it helps compensate for bad decisions, it also helps us get to the fight faster and helps us in all-domain maneuver warfare,” he said.
“We can never get enough payload capacity, so we do want submarines with large payload capacity. And what’s that going to look like in the future and how’s it going to be modular and customizable is going to be important. Of course, stealth is important, but not just acoustic stealth. It’s stealth across all spectrums. When this new SSN rolls out, we are going to have peer competitors that are going to be able to detect us not just acoustically but through algorithms that are going to break the water interface. And so those capabilities, we think, are coming, and we have to build and basically remain clandestine with those types of capabilities in play.”

VPM_firing_undersea.jpg
ADM Frank Caldwell, the director of the Naval Nuclear Propulsion Program and a senior submarine officer in the Navy, echoed in his remarks the three design options and said that “key in all of this will be our focus on speed, warfighting capability, greater energy, lethality and sensors, and, yes, the next level of stealth. I want you to know that we are working on this very actively as an enterprise.”

USNI News previously reported that the Navy may be leaning towards a Columbia-like hull for its next attack submarine. With the much wider diameter comes the ability to achieve greater speed and stealth. An SSN(X) design like this would be reminiscent of the Seawolf design – which was used for just three submarines as the Cold War was winding down but is considered the Navy’s most capable attack sub.

In a separate presentation during the event, Congressional Research Service naval affairs specialist Ron O’Rourke said, “I remember one person in public describing the Seawolf class as a boat that was designed to go up into the Soviets’ backyard and do a lot of damage before it had to come home to be rearmed – and so it was designed to be a fairly fast submarine and heavily armed, especially compared to the Los Angeles-class design of the day. So in light of the Navy now talking about this next-generation attack boat being fast and heavily armed, it would not be surprising, as some people have speculated, if that submarine were to have a diameter similar to that of the Seawolf or the Columbia-class design, something in the range of 40 to 43 feet.”

If that were to be the case, he said, SSN(X) might have a similar diameter to Seawolf but a greater displacement, due to modernization in engineering such as the SSN(X) likely having a larger electric drive system instead of a mechanical one.
 
I expect that the SSN(X) will be a Columbia-class in the engineroom, because that's the most advanced plant available right now.

You already have all that worked out for maximum quietness. I'm assuming natural circulation at full power based on what they have talked about with the Ford-class plant. So the rest of the hull will be 43 feet in diameter. This gives the potential for the much shorter and lighter SSN(X) to be as much as a third faster than the Columbia, based on the difference between the Skipjack class and the George Washington class (GW was literally SkipJack but with a missile compartment amidships, they cut SSN589 in half and reordered as SSBN598). Not the best comparison for a performance estimate, but it's the closest conceptually to what I'm picturing. I don't believe any of the later boomers were so closely based on the counterpart fast-attacks.

This also gets you some economies of scale, since you've already designed and paid for that engine room. Every place you can squeeze out a few more dollars savings is good, because these are going to be expensive boats.

But now we gotta talk about mission. What's the SSN(X) supposed to go do? It's not "hide with pride" like the Columbia. It's to go hunting. To go and take down an entire carrier group. Likely solo. This means a very large torpedo room, whether or not there's any VLS. I'm somewhat agnostic on whether there will be any VLS. I mean, Seawolf class was designed without it, and it's not like the design work hadn't been done for the 688 VLS by then, that was part of the second flight, not even the 688i. But in terms of not having some weapons in the torpedo room? Absolutely! If they don't need any babysitting by the TMs, leave them stuffed in a ready-to-launch tube someplace.

This is where I need to detour and talk about the "large payload SSN" for a second, because I think it's also going to be a shortened Columbia, for much the same reasons. I highly doubt it will have all 16 Trident tubes, not least because of arms control treaties that limit the number of deployed launchers. That's why the Ohio SSGNs happened, the US needed to decommission 4 Ohios and the first 4 boats were all in excellent material condition, still had 20 years of hull life left in them. (Those treaty limits also put a hard limit on the number of boats in the Columbia class, max of 14.)

So I'm expecting a visibly shorter SSGN, probably only 8-12 tubes, something that can be seen on a satellite photo. And the forward two tubes will be 102" diameter diver chambers, not missile capable at all, same setup as on the Ohio SSGNs. Leaves a max of 70 Tomahawks (or equivalent), 56 if the SSGN is carrying a Dry Deck Shelter on top with 12 tubes; 42/28 for the 8 tube version.

Now comes the fun question: Does the SSGN have the SSBN front end like the Ohio class or the take-no-prisoners front end like the SSN(X)? Because if you're sticking a 50+ space torpedo room on the front of the SSGN, you can get away with a shorter midships section for missiles, load more into the torpedo room. As long as they're set up to be launched horizontally, of course, but any submarine launched weapon should be. If one isn't? The entire development and procurement team needs a Gibbs-smack.

I can see arguments either way for which bow to use. Using the Columbia bow makes life easy and the SSGNs cheap. Minimal redesign to the Columbia class, just one or two fewer Trident quads and the deletion of all the strategic-related systems so it's a major refit to install Tridents into the "SSGN" hulls. And because SP tends to use up huge chunks of hull volume compared to everywhere else on the ship, I'm certain that just like on the Ohio SSGNs it'd be simple to reuse the MCC and Nav Center volumes as armory and mission planning areas for special ops teams. Might not be able to cram quite so many in as on the Ohio SSGN, though. May only be 32ish instead of 65 like on the Ohios, though I would certainly try to make 65 fit.

Given that they're talking about doing SSGN production at the end of the Columbia run, the front end of the SSN could certainly be designed by that point. Virginia production could be winding down, if not wrapped up entirely by then, so I guess the phrase is "the front end of the SSN should certainly be designed by then." As a side note, I'd really prefer to try to build some big SSGNs sooner, but maybe the 10x Flight 5 Virginias with VPM would be enough to carry the load.

Okay.

So the SSN(X) should be completely designed by the mid-late 2030s. Hopefully sooner, but I can see waiting till the Columbia class is done building to not break the bank with another extremely expensive new class. So this will probably also result in building further flights of Virginia classes out to the end of Columbia class production, then rolling from Virginia class to SSN(X) production at both EB and NNS.

Again, I'm expecting the SSN(X) to be the entire engineroom of the Columbia class, with a forward compartment akin to the Seawolf. 8x tubes, 50+ weapons, probably 50 weapons in the torpedo room and 12x VLS, using the Virginia/Vertical Payload Module setup. Also, somewhat longer tubes and weapons stows, so that something the length of the Shkval supercavitating torpedo can be carried. Mk48s are ~6m long, while the Shkval is 8.2m long. If packed nose to tail, this stretch would allow carrying 5x Mk37 sized weapons, such as Mk67 Submarine Launched Mobile Mines, in the space of two heavyweight stows. Like the Seawolf class, I expect that these will be 66cm tubes, sleeved for 53cm weapons while the bigger torpedoes are developed. If the combustion products of OTTO2 fuel weren't so toxic, it'd be interesting to have something like 4x standard tubes for things that must be impulsed out of the tubes and two very large diameter spaces for whatever could just swim out.
 

Similar threads

Please donate to support the forum.

Back
Top Bottom