DPRK 2021 Submarine missile launch

[Maro.Kyo]

You greatly underestimate the Republic of Korea's desire to be one Korea again.

Half the reason the US is on the DMZ is to keep the South from marching north!

We're in 2020s, not 1970s. There are some who desire reunification, but that doesn't necessarily mean that they want reunification through force. Most Koreans only want reunification if there are no significant negative repercussions. Majority younger generation doesn't even want reunification in the first place. Current USFK raison d'etre is not "keeping the South from marching North" - that's just bs

 

[Maro.Kyo]

Now me i'm very curious what's the next step, more heavily modified Romeos like this, or perhaps a bigger, stretched Gorae for a true modern SSB/SSG. And THAT could possibly be nuclear powered. When DPRK says something (i read that they DO have plans for SSNs) they usually put their money where their mouth is.

I don't think that SSBN makes much sense for NK. Their SSBs will operate from their small bastion close to their coast facing SoJ. It's hard to imagine the case in which the maneuverability of nuclear propulsion will come to much play for their SSB. Then it's the question of longer operational endurance, especially submerged, but with AIPs they could substantially extend the endurance as well. Of course nuclear endurance always wins over conventional AIPs but I think the noise level an AIP could offer already outweighs any nuclear propulsion NK would be able to afford, unless they opt for something like MESMA. Though, then again, there's also a question of what kind of conventional AIP NK would be able to get their hands on.

So in terms of future NK SSB/SSBN design, I think the question really lies on if the NK thinks they can get conventional AIP technology or not.

 

[BullpupRafale]

This image was posted on another forum, but if person that posted it made this or its from somewhere else.

Anyway it seems if accurate to scale that then new submarine is around 23 meters longer than Romeo.

Not just 10 as asserted by Hi Sutton.

 

[Scott Kenny]

Nonsense as average is allegedly 165cm.

My 3.5m assumes a height of 175cm, as the missile housing is right at 2x the height of the sailor standing next to it.

The muzzle door of the small diameter missile tube is then recessed into that fairing about 0.4m to allow for a hemispherical muzzle hatch and then the shutter fairing on top.

The larger tubes are roughly 1.5-1.6m, and so the muzzle hatch/top of missile is roughly 0.8m below the top of the missile housing.

Height of sail at front is over 5 meters.
5 meter for sail where missiles are.
That is section that protrudes.

Height of sail at the front may be 5m, but the height of the sail at the missile housing is not that tall. The missile housing top steps down from the height of the sail. Look at the officers that are sanding in the bridge at the front of the sail, the top of the missile housing is at roughly their foot level, ie, the missile housing deck is the same height as the deck of the bridge, then the sail goes up another meter ish for cover.

 

[Maro.Kyo]

https://twitter.com/x/status/1700264116215316991

View: https://twitter.com/EmbersOfSuns/status/1700264116215316991


Preliminary drawings by Richard W. Stirn

 

[BullpupRafale]

My 3.5m assumes a height of 175cm, as the missile housing is right at 2x the height of the sailor standing next to it.

The muzzle door of the small diameter missile tube is then recessed into that fairing about 0.4m to allow for a hemispherical muzzle hatch and then the shutter fairing on top.

The larger tubes are roughly 1.5-1.6m, and so the muzzle hatch/top of missile is roughly 0.8m below the top of the missile housing.


Height of sail at the front may be 5m, but the height of the sail at the missile housing is not that tall. The missile housing top steps down from the height of the sail. Look at the officers that are sanding in the bridge at the front of the sail, the top of the missile housing is at roughly their foot level, ie, the missile housing deck is the same height as the deck of the bridge, then the sail goes up another meter ish for cover.

Not sure how, but that is number I get with 1.65 meter average height as standard and I do not include hats nor soles of shoes.

 

[lancer21]

This image was posted on another forum, but if person that posted it made this or its from somewhere else.

Anyway it seems if accurate to scale that then new submarine is around 23 meters longer than Romeo.

Not just 10 as asserted by Hi Sutton.

If it's that big, probably it will push 3000 tons then? And as to engines i'm speculating they replaced the originals with two Gorae type engines or derivatives of, what you think? Imo this would go in hand what seems the economical approach taken with this SSB, leveraging on existing hulls and technology pioneered on Gorae. I don't know how Sutton can think the sub retained the original engines which is what, 65 years old tech, and when DPRK already built the Gorae. Not to mention DPRKs amazing advances in many other fields.

 

[Scott Kenny]

If it's that big, probably it will push 3000 tons then? And as to engines i'm speculating they replaced the originals with two Gorae type engines or derivatives of, what you think? Imo this would go in hand what seems the economical approach taken with this SSB, leveraging on existing hulls and technology pioneered on Gorae. I don't know how Sutton can think the sub retained the original engines which is what, 65 years old tech, and when DPRK already built the Gorae. Not to mention DPRKs amazing advances in many other fields.

Replacing engines gets into some pretty significant knock-on effects, though. Different weights, volume, vibration modes, mounting systems...

All US subs from the 1930s through the Seawolf class SSNs use Fairbanks-Morse 38D8-1/8" diesel engine (the GM pancake diesels were a failure and replaced by FMs), and the only reason that the Virginia-class don't use FMs is the engineers packed the machinery room too tight so they had to use newer design Cats.

If this was a completely new build boat then I'd expect newer engines like the Gorae. But this was a Romeo, chopped up and modded.

 

[Rhinocrates]

I don't think that SSBN makes much sense for NK. Their SSBs will operate from their small bastion close to their coast facing SoJ. It's hard to imagine the case in which the maneuverability of nuclear propulsion will come to much play for their SSB. Then it's the question of longer operational endurance, especially submerged, but with AIPs they could substantially extend the endurance as well. Of course nuclear endurance always wins over conventional AIPs but I think the noise level an AIP could offer already outweighs any nuclear propulsion NK would be able to afford, unless they opt for something like MESMA. Though, then again, there's also a question of what kind of conventional AIP NK would be able to get their hands on.

So in terms of future NK SSB/SSBN design, I think the question really lies on if the NK thinks they can get conventional AIP technology or not.

Just an idea... nuclear ballistic missiles are first political devices. Generally they serve deterrence, so stealth and endurance are priorities for the subs and nuclear reactors allow this. Throughout the Cold War and after, their purpose has been for their existence to be known but not their location. Actually firing them would represent a failure of the political strategy (https://www.royalnavy.mod.uk/news-and-latest-activity/operations/global/continuous-at-sea-deterrent - dramatised in the recent BBC thriller, Vigil).

I don't think that AIP or a compact nuclear power plant is NKs highest priority (at least not yet). Here's why:

I suggest that its role is for brinksmanship. NKs strategy has long been highly visible and performative - and substantially intended for domestic effect also. The boat here is as stealthy as a Scottish pipe band attacking a heavy metal concert and has the endurance of a mayfly. It would be useless in the role of an Ohio or Vanguard, but sending one to sea would serve to send a signal or even trigger a crisis which can be exploited.

Madman theory - Wikipedia

en.wikipedia.org

 

[Scott Kenny]

Just an idea... nuclear ballistic missiles are first political devices. Generally they serve deterrence, so stealth and endurance are priorities for the subs and nuclear reactors allow this. Throughout the Cold War and after, their purpose has been for their existence to be known but not their location. Actually firing them would represent a failure of the political strategy (https://www.royalnavy.mod.uk/news-and-latest-activity/operations/global/continuous-at-sea-deterrent - dramatised in the recent BBC thriller, Vigil).

I don't think that AIP or a compact nuclear power plant is NKs highest priority (at least not yet). Here's why:

I suggest that its role is for brinksmanship. NKs strategy has long been highly visible and performative - and substantially intended for domestic effect also. The boat here is as stealthy as a Scottish pipe band attacking a heavy metal concert and has the endurance of a mayfly. It would be useless in the role of an Ohio or Vanguard, but sending one to sea would serve to send a signal or even trigger a crisis which can be exploited.

Madman theory - Wikipedia

en.wikipedia.org

Which will likely result in the loss of that boat as soon as it approaches launch depth/preparations.

With 4 different nations all possible causes for the loss: Russia, SKorea, Japan, and the US. And the UK for a long shot, if they have a boat doing a WestPac. China is unlikely to play in this scenario, because they find it useful to have the North Koreans as a foil. China also doesn't want a US ally on their border, nor do they want North Korea to collapse and flood China with a couple million starving Norks that are going to take a generation to get up to speed in terms of training in modern factory procedures.

 

[BullpupRafale]

Always unhinged comments with a lot of assumptions.

 

[Rhinocrates]

Which will likely result in the loss of that boat as soon as it approaches launch depth/preparations.

Kim Jong Un must know that but doesn't care, nor would it even need to get that far. As I said, brinksmanship, not actual launch. Boutique deterrence if you will.

I'm basing my reasoning on the fact that the sub is simply incapable of performing in an Ohio or Vanguard type role. It is not stealthy and has no meaningful endurance. Its mission then is not to patrol but to go on exercises. Exercises involving this sub would maintain a general level of threat/reminder, as do the missile tests aimed at Japan that are already common.

You can send a strong message by sending one out to sea as a sabre-rattling exercise while the land-based missiles cannot be used this way - they're either on the ground or in the air but sub launched missiles add another rung to the escalation ladder. It sounds crazy but that might be the point, taking the Mad Man theory into account. If it's good enough for Richard Nixon after all...

Consider this scenario: NK wants something. For example, there is unrest at home, the population is starving again and they want food delivered, or a treaty is about to be signed that puts NK at a disadvantage. Kim announces that a sub is to be deployed with orders to stand by and to fire if demands are not met. Footage of it leaving port are broadcast (quite the opposite of the case with a true deterrent force). A bullseye is not painted on its sail because that would just be too obvious. The international media freaks out, as do the potentially rebellious home population. Western leaders now have the option of attacking the sub, which is an act of aggression potentially triggering war, or opening negotiations on a back foot. Negotiations are opened as the least worst option. Emergency food aid is delivered, the treaty is delayed or whatever. At home, the God Emperor announces that the evil outsiders have been cowed into delivering bounteous tribute, the population are reminded that they must remain united against the outside threat. The sub then returns to port, actual mission accomplished.

Variations of this have been played out many times with weapons tests and missile launches, and staging naval exercises in contested areas have long been used to exert diplomatic leverage by all sides.

 

[Rhinocrates]

Another unhinged comment.

It can't be that purpose is to gather experience with more complex configuration.
Since first ballistic missile submarine only had singe vertical launch tube.
Now they have one that has ten of them, ten fold increase.

It's possible to walk and chew gum at the same time.

By the way, I am not unhinged. I consult regularly with my doctor and take my medication as prescribed.

 

[BullpupRafale]

Article has been updated,:

H I Sutton - Covert Shores

 

[BullpupRafale]

The Sleeper Has Awakened: Six Key Takeaways From the Rollout of North Korea’s “Tactical Nuclear Attack Submarine” - 38 North: Informed Analysis of North Korea

On September 8, North Korean media announced that “a Korean-style tactical nuclear attack submarine” had been rolled out of a…

www.38north.org

 

[Scott Kenny]

Kim Jong Un must know that but doesn't care, nor would it even need to get that far. As I said, brinksmanship, not actual launch. Boutique deterrence if you will.

How many subs has Three Fats managed to lose?

Sub would go out, and just not come back in. Might not have even been deliberately sunk, just went deeper than their new hull welds can survive.

 

[Ainen]

Which will likely result in the loss of that boat as soon as it approaches launch depth/preparations.

This cavalier attitude is precisely the reason DPRK missile subs appear. Moreover, it begs a question, who's really the threat of nuclear war here.


No, you don't attack someone for sailing at periscope depth. Especially you don't do it to a deterrent of a nuclear state, which - thanks to this very attitude - will assume that excessive depth had USS on its sail.(classic safety/security dilemma)

Even if it was speaking, dunno, Russian, go prove that within 40 min.

 

[GTX]

If based upon Romeo class, these should be relatively easy to track and prosecute in time of conflict if it ever comes to that. I would expect such would be taken out rapidly and easily within the first hours of any conflict.

 

[Scott Kenny]

This cavalier attitude is precisely the reason DPRK missile subs appear. Moreover, it begs a question, who's really the threat of nuclear war here.


No, you don't attack someone for sailing at periscope depth. Especially you don't do it to a deterrent of a nuclear state, which - thanks to this very attitude - will assume that excessive depth had USS on its sail.(classic safety/security dilemma)

Even if it was speaking, dunno, Russian, go prove that within 40 min.

Periscope depth isn't launch depth.

 

[BullpupRafale]

If based upon Romeo class, these should be relatively easy to track and prosecute in time of conflict if it ever comes to that. I would expect such would be taken out rapidly and easily within the first hours of any conflict.

For that you assume no improvements were made when they made radical changes outside and inside.

 

[GTX]

For that you assume no improvements were made when they made radical changes outside and inside.

Regardless of what changes it may have had, it is still basically a 1950s - I might even say 1940s given its German Type-XXI U-boat heritage - design. Sure, it might have had some noise reduction improvements - though the extended fin/box for the missiles won't help in that regard - but it will still be a relatively easy find for any competing ASW forces (subs, ships and/or aircraft). In time of any possible war it will be a race to see whether these or the KPAAF's aircraft get eliminated first and in how many hours.

 

[BullpupRafale]

Regardless of what changes it may have had, it is still basically a 1950s - I might even say 1940s given its German Type-XXI U-boat heritage - design. Sure, it might have had some noise reduction improvements - though the extended fin/box for the missiles won't help in that regard - but it will still be a relatively easy find for any competing ASW forces (subs, ships and/or aircraft). In time of any possible war it will be a race to see whether these or the KPAAF's aircraft get eliminated first and in how many hours.

Chinese managed to reduce noise of Romeo class submarine from 160 to 140 with upgrade package in 1980's for Egypt..

Considering technology available in present day with computers that have far more processing power that can have very accurate simulations, much more is achievable along this SSB being heavily reworked such as revised nose section akin to more modern subs.

North Korea recovered Near-term Mine Reconnaissance System in 2006.


North Korea certainly learned something from this UUV.

 

[GTX]

There's only so much one can do with what is an old design.

 

[Scott Kenny]

Chinese managed to reduce noise of Romeo class submarine from 160 to 140 with upgrade package in 1980's for Egypt..

They'd need to stretch the engineroom to raft the engines (or at least the electric motors and especially the reduction gears), and probably reshape all the limber holes to prevent flow noise like blowing over the top of a beer bottle.

Neither of which are in evidence in the pictures we have.

So it's still a very noisy, slow, and short ranged SSB. Which means that even if it doesn't sink during sea trials due to build quality (like how many other Nork subs?) it is a very obvious target.

Considering technology available in present day with computers that have far more processing power that can have very accurate simulations, much more is achievable along this SSB being heavily reworked such as revised nose section akin to more modern subs.
(img deleted for space)
North Korea certainly learned something from this UUV.

They might have learned something, but without a set of CNC machines large enough to cut a 7ft propeller you just cannot make the screws that shape.

 

[BullpupRafale]

They'd need to stretch the engineroom to raft the engines (or at least the electric motors and especially the reduction gears), and probably reshape all the limber holes to prevent flow noise like blowing over the top of a beer bottle.

Except components can be made smaller with comparable performance or same volume of space with more power and or complexity.

For example we can take turbojet engines, American J79 and Soviet/Russian AL-21 with latter coming just few years after former.
Latter having 14 compressor stages compared to former 17, except latter is twin spool compared to latter being single spool.
Their volume of space is nearly identical yet due to two spool design latter has nearly 50% greater thrust than former.

Neither of which are in evidence in the pictures we have.

There is no evidence that nothing has changed inside and again, Chinese have made improvements in 1980s including automation.
Just because you are not able to see it doesn't automatically mean that its absolutely not there as that is jumping to conclusions.

So it's still a very noisy, slow, and short ranged SSB.

Neither of us don't know that, except you are confident that nothing has changed besides the obvious added section and changed nose.

Which means that even if it doesn't sink during sea trials due to build quality (like how many other Nork subs?) it is a very obvious target.

Again you make bold assertion and assumption about their build quality while also showing that you don't know about NK subs because 1 submarine was lost in 2016 and 1 in 1998 when it stumbled upon fishing net thus disabling it while another ran aground in 1996 and in 1985 Romeo sank due to accident. 4 submarines lost in 38 years out of nearly 80 they have is not even 10% of its sub fleet.

They might have learned something, but without a set of CNC machines large enough to cut a 7ft propeller you just cannot make the screws that shape.

They don't need to make a 7ft propeller to begin with as it is Romeo with single one at each side that has 7ft propeller.
Unlike this one that has two thus it does not need to be 7ft since you can have smaller with comparable or greater performance.
I am not sure why in here is not considered the progress of technology or is it outright ignored for sake of narrative to downplay the sub?

 

[GTX]

Come on now. It sounds like wishful thinking here. We are still dealing with a Romeo derivative and there is only so much which is practical and even forgetting internals, the external images already show not much has been changes that would make this more silent. If anything, it could be more noisy with that fin/box for the missiles.

 

[Scott Kenny]

Except components can be made smaller with comparable performance or same volume of space with more power and or complexity.

For example we can take turbojet engines, American J79 and Soviet/Russian AL-21 with latter coming just few years after former.
Latter having 14 compressor stages compared to former 17, except latter is twin spool compared to latter being single spool.
Their volume of space is nearly identical yet due to two spool design latter has nearly 50% greater thrust than former.

The rafting takes up significant space to add in. The original Yasen class is 10m shorter than the Yasen IIs because of added rafting.

Again you make bold assertion and assumption about their build quality while also showing that you don't know about NK subs because 1 submarine was lost in 2016 and 1 in 1998 when it stumbled upon fishing net thus disabling it while another ran aground in 1996 and in 1985 Romeo sank due to accident. 4 submarines lost in 38 years out of nearly 80 they have is not even 10% of its sub fleet.

The USN hasn't lost a boat at sea since 1968, and Scorpion had not gotten her SUBSAFE refit yet. Two subs out of some 300 made since Nautilus, over 60 years ago.

Though admittedly the DPRKNavy is doing better than the Red Navy in terms of submarine losses.

They don't need to make a 7ft propeller to begin with as it is Romeo with single one at each side that has 7ft propeller.
Unlike this one that has two thus it does not need to be 7ft since you can have smaller with comparable or greater performance.
I am not sure why in here is not considered the progress of technology or is it outright ignored for sake of narrative to downplay the sub?

? Huh? You're saying that they don't need to make a 7ft propeller because it's a Romeo that has two 7ft propellers?

Submarine propellers have gotten larger in diameter and spun slower to be quieter. A smaller, faster screw is noisier!

 

[BullpupRafale]

The rafting takes up significant space to add in. The original Yasen class is 10m shorter than the Yasen IIs because of added rafting.

Yasen-M is 10 meters shorter than original.

Rafting could be implemented if components are smaller such as piston engine replaced with turbines that are also more efficient at generating electricity.

? Huh? You're saying that they don't need to make a 7ft propeller because it's a Romeo that has two 7ft propellers?

Submarine propellers have gotten larger in diameter and spun slower to be quieter. A smaller, faster screw is noisier!

You clearly have not understand my argument. Please read again what I wrote.

7ft propeller on each side is not necessity and propeller with modern hydrodynamics can reduce noise or increase thrust or both. They could implement two propellers that are contra rotating to each other, they don't need to spun faster.

 

[Hood]

I just hope they have tested this extensively in the tank and in simulation software.
It had a new midships plug, a much longer and taller conning tower, a shorter bow of new configuration which is hemispherical and wider at its forward end than the original bow and repositioned diving planes. The buoyancy, trim, diving performance and underwater handling of this submarine is going to be very different to the standard Romeo.

 

[Scott Kenny]

You clearly have not understand my argument. Please read again what I wrote.

7ft propeller on each side is not necessity and propeller with modern hydrodynamics can reduce noise or increase thrust or both. They could implement two propellers that are contra rotating to each other, they don't need to spun faster.

Read my argument again. Submarine screws have gotten larger and larger diameter (I don't even know how big the screw on an Ohio is, but it's a lot bigger than 7ft on each side like on the Nautilus). This allows them to be spun slower for the same thrust.

Just a comment on this nonsense about the DPRK SSBG being too old, or too noisy, or too slow or whatever. It simply does not matter. This subs purpose is to add yet another leg to DPRK's nuclear deterrent. It will stay close to the friendly shore under the cover of friendly forces (perhaps that's one of the impetus for the recent modernization of the surface forces, helping protect the SSBGs), carrying 10 nukes. If they convert say a dozen, that's 120 warheads, and more if the SLBMs can be MIRVed. And if, IF there is a war and the americans attack DPRK, you can be sure they won't be obligingly sail around for hours and wait to be attacked by an US sub as someone implied previously. It will all be over in the first 10 minutes or whatever long it takes for the DPRK sub to launch. Good luck to the americans finding and destroying them all in 10 minutes, nevermind all the other nukes on land, road-mobile and perhaps even submerged barges.

You don't understand just how critical quieting is to a submarine.

A submarine that isn't quiet is nothing more than a slow target.

So they won't wait for hours for the americans to pick DPRK's nuclear deterrent one by one. and i don't think anyone in DPRK has any illusions about withstanding a conventional attack (despite huge advances in conventional weapons in DPRK in the last decade) from the americans and their various vassals, the numerical, air, and naval discrepance is just overwhelming. This is why they developed nukes to begin with, to prevent a US attack against DPRK such as in Iraq, Serbia, Libya, Syria etc.

DPRK can already drop so much conventional HE on Seoul that it's measured in kilotons per second.

So in conclusion, the subs role is to PREVENT such a war in the first place by assuring another MAD leg. The DPRK chose the cheapest and quickest and as of now economically feasible way to add this deterrent leg by converting the Romeos. And me i think they incorporated the know-how from the Gorae, apart from the visible changes it probably has Gorae engines and props o derivatives of. The overall package being for now sufficient enough for DPRK's requirements.

A submarine that everyone knows the location of is not a deterrent.

 

[BullpupRafale]

Read my argument again. Submarine screws have gotten larger and larger diameter (I don't even know how big the screw on an Ohio is, but it's a lot bigger than 7ft on each side like on the Nautilus). This allows them to be spun slower for the same thrust.

Read what I wrote again as your reply doesn't make sense to what I wrote.

 

[lancer21]

Sutton now thinks the 2019 sub and Kim Gun Ok are two different subs.

H I Sutton - Covert Shores

 

[Hood]

I think that is probably a safe conclusion given that the extent of the changes are major compared to what was seen in 2019 - and details like the snorkel housing seem to clinch that.

Against that we have to consider has 'Sinpo-C' ever been seen at sea? It would seem strange given all the fanfare surrounding 'Hero Kim Gun-ok' and all other NK nuclear assets that they continuously promote that we've not actually seen the 'Sinpo-C' since 2019. Was the conversion abandoned in favour of the larger missile bay idea?

Given that both are 'Romeo' conversions it would indicate that new-build construction of 'Romeo' hulls stopped some time ago. That in itself is limiting given the number of available hulls and it does mean that major powerplant changes are perhaps very unlikely. It makes me doubt now how much of the inner pressure hull forward really has been changed on the 'Hero Kim Gun-ok'.

 

[Scott Kenny]

Read what I wrote again as your reply doesn't make sense to what I wrote.

You said, and I quote:

They don't need to make a 7ft propeller to begin with as it is Romeo with single one at each side that has 7ft propeller.
Unlike this one that has two thus it does not need to be 7ft since you can have smaller with comparable or greater performance.
I am not sure why in here is not considered the progress of technology or is it outright ignored for sake of narrative to downplay the sub?

Now.

While I admit that I don't know how big the prop on a Romeo is, the Nautilus had a pair of 7ft props. Spent enough time polishing the one outside the admin building on Bangor... Nautilus had a bit more hp per shaft than a Romeo, 13khp split between two shafts (6500hp each not counting losses) while the Romeo has 2x 4khp, so a Romeo may have a smaller prop than 7ft. Doesn't matter.

Because if you want a quieter prop than what came with the Romeo class, you need a CNC machine able to handle a prop of at least the same diameter.

You also need to redo the reduction gears if you make a larger diameter prop to keep the tip speed down.

The only way to avoid changing reduction gears and reduce tip speed is to make a smaller diameter prop with more aggressive pitch to maintain thrust. This also needs very careful shaping to avoid cavitation. The blades of submarine propellers are highly swept, wide chord, and the entire prop may be shaped more like a cone than a flat circle. Making such a prop requires a very fancy CNC machine.

 

[GTX]

View: https://youtu.be/Fn5K2iUoJyc?si=30_dbOVFoNkx7zwt

 

[Rhinocrates]

This might be a handy reference.

View: https://www.youtube.com/watch?v=ugSEIiTZ1Pg