Rumoured "mini-nuke/diesel" Submarine SSK-N(?) thread

[obj 705A]

What I've criticized is the idea that the SSKN can take on the mission that proper SSNs take, due to their inability to compete with SSNs in terms of transit speeds and tactical speeds, and most importantly the ability to attain those speeds in a manner which is sustained, long duration and also being able to maintain sufficient stealth.

I don't think any one here is saying the SSKN can replace the Type 093B & the Type 095 in the far seas. It's just that putting a nuclear reactor on an SSK would allow it to remain underwater indefinitely so it doesn't get detected and extend it's range limited only by the amount of food carried. I guess probably the SSKN would probably operate up to the 1st to 1.5th island chain.

 

[Blitzo]

I don't think any one here is saying the SSKN can replace the Type 093B & the Type 095 in the far seas. It's just that putting a nuclear reactor on an SSK would allow it to remain underwater indefinitely so it doesn't get detected and extend it's range limited only by the amount of food carried. I guess probably the SSKN would probably operate up to the 1st to 1.5th island chain.

This is the post which started my entry into the discussion, and I'm not sure why people have continued entering the discussion if they don't actually hold the position written:

Not just the endurance, it will perform the role of nuclear attack subs exponentially better.

1. It is more cost effective, allowing it to take more risks.
2. It is harder to detect, which also makes it safer all else equal.
3. There will be more of them, which allows it to over more area at once, stretching defenders thin. This in return also make it safer to operate.

low cost x stealthier x quantity = effectiveness

The multiplitive effect will be greater than sum of the 3.

I have no inherent problem with the idea of the SSKN if it works and if it is at a reasonable cost and within their acceptability for complexity -- in fact it may well be an excellent replacement for SSKs and if so then the PLAN would absolutely be idiotic to not buy SSKNs.

However I also am adamant that the SSKNs with the characteristics that have been described in rumours, cannot and will not perform the role of a proper SSN that is known and in operation among leading navies today.



If you are saying that the SSKN will not be able to perform the same mission as a 09IIIB or 09V, and that the SSKN can do the job of a SSK better due to much superior endurance and is intended to operate in 1st to 2nd island chain distances, then great, we are in complete agreement.

 

[tankphobia]

I feel like we're getting ahead of ourselves here. More often than not when some rumor mill conjures up a new platform for the PLA with some amazing tech it almost always gets watered down to something more conservative in the end, the most recent example I could think of would be Z-21. The US and Soviet both tried building small SSNs, but they both eventually decided to go with a full size SSN afterall.

 

[gelgoog]

The US never had enough automation in their subs to make small subs really viable. The Soviets achieved this with the Alfa class submarine. But they had issues with the liquid metal reactor it used. No to mention that making titanium hulled subs is really expensive. Later classes had less compact light water reactors and steel hulls to enable mass production.

 

[antiterror13]

I feel like we're getting ahead of ourselves here. More often than not when some rumor mill conjures up a new platform for the PLA with some amazing tech it almost always gets watered down to something more conservative in the end, the most recent example I could think of would be Z-21. The US and Soviet both tried building small SSNs, but they both eventually decided to go with a full size SSN afterall.

The French did that with Rubis ~2,500 tons and also with Barracuda ~5,000 tons

 

[tphuang]

A Stirling engine is smaller than a steam generator + turbine though. Based on actual photos of the Swedish variant it is approximately human sized. To be rough, let's call it 1 m3.

You will never find a single steam engine with volume anywhere near 1 m3.

And you have to think is the output nameplate value after efficiency conversion or before. Because if it's before efficiency multiplication then it makes no sense. 40% is about the Carnot limit for like 600-700K heat source 300K drain, and there can be no engine more efficient than the Carnot limit.

So if it's 320 kW pre efficiency then it's a nonsensical value since the heat input is from the reactor whose output is independent of the efficiency of the Stirling engine.

Swedish one is less powerful than Chinese one, so it is going to be smaller. And you want 6 of them. You also need machine that takes input from all 6 machines and output to your electric motor directly or charge battery. And you need a lot of rafting around that. There is no getting around space utilization on this.

Single steam turbine would just require rafting 1 turbine. It wouldn't be much different than how they would raft one on a larger submarine

 

[tphuang]

I don't think any one here is saying the SSKN can replace the Type 093B & the Type 095 in the far seas. It's just that putting a nuclear reactor on an SSK would allow it to remain underwater indefinitely so it doesn't get detected and extend it's range limited only by the amount of food carried. I guess probably the SSKN would probably operate up to the 1st to 1.5th island chain.

it's debatable whether the thus far discussed min-nuke can remain underwater indefinitely

you need atmosphere control equipment (which takes a lot of power) to operate underwater without having to ventilate. Without that, you still have to get to PD for maybe 30 minutes a day to ventilate. Better than completely surfacing for hours to recharge like a conventional diesel power submarine, but it's still not great

 

[Alfa_Particle]

I feel like we're getting ahead of ourselves here. More often than not when some rumor mill conjures up a new platform for the PLA with some amazing tech it almost always gets watered down to something more conservative in the end, the most recent example I could think of would be Z-21. The US and Soviet both tried building small SSNs, but they both eventually decided to go with a full size SSN afterall.

Sorry, just a slight O/T correction about the Z-21.
If you're referring to the rumors about an attack helo with coaxial rotors and rear propulsion but the Z-21 ended up being more conventional, i.e. Apache-like and based on the Z-21, IIRC insiders in Weibo (couldn't find the posts rn unfortunately) said that the Z-21 was just an emergency stop-gap helo developed from basically completely from off-the-shelf components. The coaxial one is still in development afaik.

 

[plawolf]

Swedish one is less powerful than Chinese one, so it is going to be smaller. And you want 6 of them. You also need machine that takes input from all 6 machines and output to your electric motor directly or charge battery. And you need a lot of rafting around that. There is no getting around space utilization on this.

Single steam turbine would just require rafting 1 turbine. It wouldn't be much different than how they would raft one on a larger submarine

Why are you guys arguing like you think this rumoured SSKN will be a direct competitor to traditional SSNs when it makes so much more sense for this to be a complimentary partnership?

The best arguments for the SSKN is for it to be offered as an upgrade path for existing SSK designs to drastically improve their endurance without needing to do much re-designing.

This in turn means that China can utilise its existing vast SSK production base to pump out large numbers of SSKNs in a short period of time on top of full pace SSN production at Huludao.

This then means that the PLAN can just redeploy its existing SSK crews to man the new SSKNs with minimal re-training needed while it’s naval academies focus on pumping out the next gen nuclear submarine crews.

This would not make a whole lot of sense for most navies, but then most navies are not looking at potentially getting into a full spectrum direct fight with the USN and friends before the decade is out.

I see the SSKN programme as a means for the PLAN to achieve a quantum leap in the capabilities of its SSK fleet at comparatively modest cost that can be deliverable within a surprisingly short timeframe. That would then fundamentally change the way it can fight within the first island chain and beyond and free up all its new SSNs to go further out into the deep blue and operate to their specific strengths.

 

[Rank Amateur]

Why are you guys arguing like you think this rumoured SSKN will be a direct competitor to traditional SSNs when it makes so much more sense for this to be a complimentary partnership?

The best arguments for the SSKN is for it to be offered as an upgrade path for existing SSK designs to drastically improve their endurance without needing to do much re-designing.

This in turn means that China can utilise its existing vast SSK production base to pump out large numbers of SSKNs in a short period of time on top of full pace SSN production at Huludao.

This then means that the PLAN can just redeploy its existing SSK crews to man the new SSKNs with minimal re-training needed while it’s naval academies focus on pumping out the next gen nuclear submarine crews.

This would not make a whole lot of sense for most navies, but then most navies are not looking at potentially getting into a full spectrum direct fight with the USN and friends before the decade is out.

I see the SSKN programme as a means for the PLAN to achieve a quantum leap in the capabilities of its SSK fleet at comparatively modest cost that can be deliverable within a surprisingly short timeframe. That would then fundamentally change the way it can fight within the first island chain and beyond and free up all its new SSNs to go further out into the deep blue and operate to their specific strengths.

"This then means that the PLAN can just redeploy its existing SSK crews to man the new SSKNs with minimal re-training needed while it’s naval academies focus on pumping out the next gen nuclear submarine crews."

Based on my limited understanding, moving a diesel-electric submarine crew to a nuclear-powered boat will require quite a bit more than "minimal" re-training, at least with regard to operating the reactor.