09V/09VI (095/096) Nuclear Submarine Thread

[Blitzo]

So if China is capable of building a 200MWt ACPR50S, it would seem to me that building a 200+ MWt reactor for submarine should be a given at this point. Given the size of Akula and Yasen class, I think the next Chinese SSN will be huge.

Isn't the Virginia's S9G 210MWt?

 

[AndrewS]

The ability for H-20 with SDB type weapons to conduct re attack against Guam and other second island chain targets, is of course not something that my description of SSNs are intended to perform.

However, I believe a number of competitive SSNs with enhanced VLS capacity is the only way to achieve the mission I described in previous posts "near-permanent/round the clock deployment of a large number of munitions in relatively close range to second island chain region (including and beyond Guam), from a variety of axes of attack relative to potential targets."

I think having a variety of axes of attack is not really required.

Guam is a small island with literally a single naval base and a single airbase.
It means that any deployed medium/long-range air defence systems will be able to cover all the potential axes of attack, which includes land-attack missiles launched from different direction from SSN VLS tubes.

So that just leaves a requirement for permanent/round the clock deployment of large numbers of munitions able to reach the 2nd Island Chain.

The reason why warning time is important, is not primarily due to the ability of Guam to get its aircraft off the ground.

Rather, the reason why warning time is important, is that it allows the missiles and/or aircraft that are launched from land to be tracked for 3000-4000km from their launch sites to Guam, and enable rings of US air and missile defenses between the first island chain, up to and including Guam, to be able to have longer opportunities to discriminate and track targets enabling a higher chance of successful interception, as well as more opportunities to intercept them as well.

Being able to launch weapons closer to your target not only reduces the time that the opfor is able to track the missiles that you've launched (thus reducing chances of a successful interception), but also reduces the opportunities to intercept them as well.


Think about Guam's defenses as a multilayered onion that has to be peeled through to get to the core.

The outermost layer, in the 1st island chain, are US assets in the first island chain. Land based BMD radar and BMD batteries, land based fighters with AEW&C, and even naval ships with BMD capability.
The middle layer is between the 1st and 2nd island chain, composed of carriers, naval ships with BMD, and perhaps small islands with forward deployed smaller BMD radars and BMD batteries.
The final layer is in the 2nd island chain, including Guam and smaller islands that have their own land based comprehensive BMD and land based airbases with fighters and AEW&C, as well as escorting naval ships with BMD, perhaps carriers as well.

All of those layers will seek to track PLA land based missile and aircraft attacks launched towards Guam, as well as seek to shoot them down and thin them down as much as possible before they reach Guam. In other words, PLA attacks from land will have to go through three layers of defense, because at the commencement of hostilities, those land based weapons are naturally not forward deployed close to Guam.

Now, for SSNs with VLS, if they are routinely deployed close to Guam in the 2nd island chain, they are able to bypass basically the outermost layer and middle layer of defenses, straight to the final layer of defenses -- or perhaps even get within the final layer of defenses! That is in addition to the fact that they can attack from other directions where the outermost and middle layers of defenses are either weak or absolutely nonexistent by virtue of the geography of the middle pacific.
That is why the importance of having routine forward deployment close to potential targets is important.


As I wrote before, yes the PLA can try to conduct offensive strikes against the outermost and middle layers of defense that the US has, to weaken them to enable a strike with greater chances of success against Guam. And I expect the PLA to do so.
But that will require time and materiel, and even then I believe the likelihood of success will remain greatly enhanced when a large fraction of the first strike is delivered by a number of SSN-Gs that are already prepositioned and operational close to the target.

I don't see interception of hypersonic weapons as being practical, even if they are detected and tracked from launch with some 15-20 minutes of warning time.

A DF-26 has a re-entry speed in excess of Mach 10 which will be very difficult (impossible?) for THAAD to hit, particularly since the DF-26 re-entry vehicle will also be manoeuvring. And even if it is hit, a payload of tungsten ball bearings will still continue on roughly the same trajectory and speed towards the base. A similar rationale applies to DF-17 glide vehicles and other hypersonic missiles.

So hypersonic weapons bypass the inner and middle layer of defences, which forces the defenders to defend with very expensive SAM systems which cost more than the attacking missiles.

In comparison, submarine launched VLS cruise missiles will definitely be tracked from launch and will be engaged by medium-range SAM systems and SHORADs. And even if you salvoed 480 JASSMs in one go, I expect many (most?) will be shot down.

And JASSMs are more expensive than defending SHORAD and medium-range SAMs.

---

So if I had a deployed fleet of 12 SSNs with 480 cruise missiles, I'd use them on targets beyond the 2nd Island Chain like Pearl Harbor, and leave Guam to the DF-26 and H-20

 

[AndrewS]

Remember, nuclear energy is expensive and not so competitive with coal or wind/solar. Even the large nuclear reactors are really not competitive right now in terms of cost of construction and operation. 125 MWe of electricity, which according to wiki is the same as what A1B reactor on Ford class generates.

That statement is not accurate in China.

The "standard" is $2 Billion for 1000 MW of nuclear reactor capacity built in a 5 year timeframe, with no surprises.
If you assume borrowing costs of 5% per year and a 30 year repayment term, it means nuclear energy can match the 4.2cents/kWh wholesale rate paid for coal electricity in China and still have a small profit. Then profits increase significantly from Year 30 to Year 60 of operation.

Wind and solar can have even lower costs, but those savings are eaten away by the costs of battery storage to even out supply.
The cheapest grid battery currently works out to 11cents/kWh, then you have to add the cost of the wind/solar electricity.
I reckon grid battery costs would have to drop by roughly 3x before wind/solar are competitive against coal/nuclear.

But as mentioned previously, this is for China.
Nuclear reactor costs in the West are far higher.
Also, Russian reactors look even cheaper to build/operate and they provide lower cost financing which significantly reduces the final cost of electricity.

Anyway, back on topic.

EDIT. If you extend the repayment terms for a nuclear reactor to 50 years and provide borrowing at 1% per year, the cost of nuclear electricity would drop to 2.4cents/kWh. That would be more competitive than wind or solar.

 

[Jason_]

They most certainly cannot.

The capability that a large fleet of competitive SSNs with large cruise missile loads enables for the PLA -- which bombers witb ALBMs cannot offer -- is near-permanent/round the clock deployment of a large number of munitions in relatively close range to second island chain region (including and beyond Guam), from a variety of axes of attack relative to potential targets

I get your arguments but consider:

• The benefits of multi-axis attack are diminished in the age of AESA radars and ARH interceptor missiles as radar refresh rate cannot be exploited.
• Closeness to target does not translate to shortness of warning time. A 0.7 Mach cruise missile takes around 750 seconds to travel 100 nm/180 km. An IRBM (DF-26) takes about 770s to travel 3000km (Shanghai to Guam) (From
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  time(s)=sqrt(range(km))*14). Shorter if fired on depressed trajectory.
• The value of a first strike diminishes in a sustained conflict, whereas the value of sustained affordable firepower increases.
• Since we should expect substantial US repair capacity for basic infrastructures like runways, a strike should seek to target high value non-repairable assets, such as radars and fighters. However, a submarine’s poor ISR capability relative to bombers make sub launched missiles worse in this task. For example, bombers could use its EW suite to identify radar sites, or fire cruise missiles with man-in-the-loop terminal guidance.
• Cruises missiles fired from submarine in your CONOP does not seem to be compatible with EW support, certainly if you intend to fire them off the main axis.
• The USAF is practicing the
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  (ACE), where assets are dispersed over dozens or hundreds of smaller bases, precisely to withstand a first wave attack. This further stresses the needs for high volume of weapons and sustained firepower.
• Bombers are substantially more flexible in terms of payload. Other than Tomahawk-like cruise missiles, possible payloads include NSM/SLAM-ER/KD-88 sized cruise missiles that could double the missile count, HARMs, loitering munitions, submunition dispensers, and glide bombs. A Mach 3-4 class precision ground attack weapon could be the standard high end air to ground weapon of the future.

Something like this cannot be fired from subs.

So, think about it -- that is up to 15 SSNs (of which at least 12 are SSN-Gs) carrying at least 480 VLS tubes between them, very hard to detect and track, virtually permanently in the second island chain, anywhere between 1000km to a few hundred km of Guam and other US installations in the second island chain.
That is to say, virtually at every moment of every day, able to launch their payloads on short notice. (During times of increased tension or build up to conflict, of course more SSNs will be surged.)

So, the comparison with bombers isn't really accurate, because think about how many bombers and support aircraft you'd need to do the same thing?

This depends on how you define “the same thing.” Certainly if it is simply 24hr continuous forward deployed missile count, you could argue that subs are better. However, I would suggest a more appropriate measure to be damage dealt to targets, in which case the bombers’ sustained firepower is unparalleled.

Let's say a H-20 can carry 16 equivalent weapons to what a VLS tube on a SSN/SSN-G can carry. Okay.
Then let's consider that the requirement, is for you to have 480 equivalent weapons in the air, within 1000km to a few hundred km of Guam/in the second island chain, 24/7 (i.e.: virtually every moment of every day, for years if not decades on end), in a manner that is very hard for the enemy to detect and track.

To get 480 weapons in the air, you'd need 30 H-20s. Not too bad right? And they can totally fly within 1000km to a few hundred km of Guam, based on how big we expect H-20 to be.

But the problem arises with the 24/7 part, and the detect/track part.

For the 24/7 part -- basically, the challenge you face is needing to permanently have 30 H-20s in the air on station within 1000km of Guam for years if not decades. Yes, that is achievable, but you'd probably need to produce many hundreds if not a few thousand H-20s to maintain that kind of sortie rate for years/decades. It'll be a veritable conga line of H-20s constantly having to leave China, loiter on station 1000km from Guam for maybe 3-4 hours, then fly back just as another H-20 arrives to replace it on station, multiplied by 30, ongoing 24/7 for years/decades.

For the detect/track part -- this comes down to the nature of bombers (even stealth bombers) versus submarines, namely that bombers loitering in an area 24/7 will be much more easily detected and tracked -- even visually by an intercepting pilot with a Mk-1 eyeball, than a stealthy submarine can.
The threat posed by SSNs is just that much greater, which will place more demands on monitoring and countering them than persistent bombers that are permanently in the air.

Can you clarify what sort of war scenario would the submarines' ability to launch its weapons instantaneously be so preferable to a bomber's ability to launch weapons in 5 hours?

Now, I want to emphasize that my proposed "12-15 SSN-G in 2IC" idea isn't intended to be a single action by the SSN-Gs alone. Instead, they achieve two things in relation to their effects against the opfor on land/surface:

1. During peacetime, significantly complicate opfor strategic defense measures and force them to expend money, base infrastructure, and place operational pressure on ASW missions and to force them to defend against the prospect of a multi-axis missile attack -- all of which will result in much greater divided resources, planning, and attention, to both ASW and AAW, in a multi-axis large area manner.

I disagree with this for two reasons. First, given what the US is already doing/already have, defending against multi-axis missile attacks requires fewer additional resources than defending against the diversity of weapons that can be launched from bombers. Cruise missile defense is most ideally performed using AWACS like the E-2 and E-7 that the US is already purchasing and air to air missiles launched from fighters that the US already have. Whereas stealth missile, loitering munitions, smart bombs, HARMs, medium range supersonic air to surface missiles and air launched decoys which can be fired in any combination thereof pose much greater challenges to air defenses.

Second, the US' most capable and numerous air and missile defense system is its Arleigh-Burke destroyers and eventually DDG(X), which would be threatened by SSNs with or without cruise missiles. So there will be immense pressure on ASW missions regardless. If anything, SSNs would achieve a greater level of air and mission defense degradation and resource division if they spend their time stalking US DDGs instead of being prepositioned off Guam, as this would compel US destroyers to operate only in groups and within ASW protection bubbles.

 

[tphuang]

Isn't the Virginia's S9G 210MWt?

I believe so. I'm also of the understanding that pump jet propulsion is a little less efficient than 7 blade propellers, so some of that additional power is wasted. Virginia may also have higher onboard electricity requirement. It's also quite possible the smaller size allows Virginia to got 1 or 2 knots faster than Akula.

ACPR50S is more efficient (30%) than KLT-40S (23%) in thermal to electricity generation. I think it's quite likely that a future Chinese 200+MWt reactor will be more efficient in powering submarine than even the latest variant of OK-650. That could allow them to attain higher speed and have more internal space.

A DF-26 has a re-entry speed in excess of Mach 10 which will be very difficult (impossible?) for THAAD to hit, particularly since the DF-26 re-entry vehicle will also be manoeuvring. And even if it is hit, a payload of tungsten ball bearings will still continue on roughly the same trajectory and speed towards the base. A similar rationale applies to DF-17 glide vehicles and other hypersonic missiles.

Yet, SM-3 has demonstrated capabilities to intercept even faster ICBMs. That's why I think this PLAN strategy of developing ASBM, HGV and HCM for anti-ship missile is a good one. Having different flight profiles is so much harder to pick up and intercept.

That statement is not accurate in China.

The "standard" is $2 Billion for 1000 MW of nuclear reactor capacity built in a 5 year timeframe, with no surprises.
If you assume borrowing costs of 5% per year and a 30 year repayment term, it means nuclear energy can match the 4.2cents/kWh wholesale rate paid for coal electricity in China and still have a small profit. Then profits increase significantly from Year 30 to Year 60 of operation.

Wind and solar can have even lower costs, but those savings are eaten away by the costs of battery storage to even out supply.
The cheapest grid battery currently works out to 11cents/kWh, then you have to add the cost of the wind/solar electricity.
I reckon grid battery costs would have to drop by roughly 3x before wind/solar are competitive against coal/nuclear.

But as mentioned previously, this is for China.
Nuclear reactor costs in the West are far higher.
Also, Russian reactors look even cheaper to build/operate and they provide lower cost financing which significantly reduces the final cost of electricity.

Anyway, back on topic.

EDIT. If you extend the repayment terms for a nuclear reactor to 50 years and provide borrowing at 1% per year, the cost of nuclear electricity would drop to 2.4cents/kWh. That would be more competitive than wind or solar.

This is not really the right thread to argue about this. My point was that small nuclear reactors on FNPP aren't a very competitive form of energy source. There is a very small set of use cases that make commercial sense for them. That's why only Russia/China have built them. If you already plan to build a large number of similar reactors for your submarine, then building FNPP helps lower your production cost and reduce maintenance for both the submarines, ice breakers and FNPP. In this case, ACPR50S is of the exact size and thermal power generation that you'd want for a submarine, so I'd imagine there is a lot of commonality with version that goes into a submarine.

 

[AndrewS]

I believe so. I'm also of the understanding that pump jet propulsion is a little less efficient than 7 blade propellers, so some of that additional power is wasted. Virginia may also have higher onboard electricity requirement. It's also quite possible the smaller size allows Virginia to got 1 or 2 knots faster than Akula.

My understanding is that pump jets are:

1. At low speeds, are vastly less efficient than a propeller. And the slower the speed, the more inefficient it is.

2. At higher speeds, significantly less efficient than a propeller. But it does have the benefit of less blade tip cavitation due to the increased water pressure entering the housing.

 

[SEAD]

delete

 

[SEAD]

Was this shared here? This was allegedly a souvenir ordered by the Huludao Shipyard. My opinion is it looks real (not CGI) and it looks like a high-quality and detailed souvenir. Pump-jet and 12 VLS tubes are visible. The sonar looks like cylinderical array and there is no hint of sophisticated shaping of the hull as we see on Taigei or Dreadnough. Its inner hull is almost as big as the outer hull which means large internal space.
View attachment 88583

It looks more like the new satellite image than a future one?

 

[Andy1974]

If we are talking about coordinated saturation strikes against CBGs, submarines which rapidly launch all torpedos in quick succession is more interesting than contributing to already sufficient air strikes.

Having the VLS loaded with fast, stealthy missiles is a great way to attack an enemy’s supply chains and homeland, so I think they will be fitted to a lot of subs as standard.

 

[BoraTas]

It looks more like the new satellite image than a future one?

Yes. Exactly. Almost to an eerie level. It has VLS and pump-jet but it is a 093 in hull shape. And the sub on the new satellite photo looks like an 093 but has covers on places where VLS and pump-jet would be.