The future Columbia class SSBN(X)'s reactor may be as quiet as SSKs on Battery

How should this diagram be altered to represent a Heat Exchange Reactor with Electric Drive? Diagram courtesy Bright Hub Engineering.

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One of the quieting/stealth features on the future Columbia class SSBN(X) is a possible heat exchanger quiet mode in its proposed S1B reactor. This reactor is also called Columbia Program Element PE0603570N/Project 3219 (see page 32).

Apparently the S8G reactor on the current Ohio SSBN already uses a heat exchanger. I think it logical that the heat exchanger aspect will be carried over to the future Columbia.

Minimising moving parts contributes to quiet mode. Such a quiet mode may ideally be available when future Columbia's are operating at their (about 5 knots?) on station cruising speed. 

The heat exchanger tip comes from Josh in Comments on 29/9/16 12:23 AM: 

"And important attribute of the S8G fitted to Ohios is that it is a natural circulation reactor (at least at low power), relatively revolutionary at the time. The core is placed low and the heat exchanger placed high in the primary coolant loop such that the hot coolant rises to the exchanger then falls back down the other side of the loop once cooled off without the use of a pump. This eliminates an entire type of noise from plant, at the cost of size and weight apparently. The wider hull of a boomer makes this more practical to do in an SSBN than an SSN. Its not clear if the practice carried through to the Seawolf or Virginia's reactors; it might well not have been for size reasons or because more cost effective means of quieting coolant pumps became available (turbopumps, electrical systems that remove the 'snap' noise of pump engagement, etc).

Its also worth noting that any SSBN would spend its patrol at 5knts unless it was fired upon. The pump jet arrangement would only be advantageous getting to station. The Russians likely have much more reason to worry about being tracked during transit than the Americans due to their [Russian] base geography and possibility of USN SSNs off their SSBN bases at any given moment. The USN keeps boats deployed off Russian coasts at much more often than the reverse case, even during the cold war. I suspect its quite the rarity for an Akula [SSN] to appear off Maine [Kings Bay, Georgia SSBN Base] or [Bangor in Washington state] these days."

Other features contributing to the Columbia's quietness/stealth will be electic drive, X-plane rudders and pump jets - on these see this 2013 reference and a major briefing to Congress August 18, 2016 reference. 

If all of these features are in the Columbia's and perhap future US SSN(X)s they may make them quieter than SSKs on battery mode.

Submarine Matters' mentions of Columbia class stealth are at articles dated September 28, 2016

and August 24, 2016.

"Japan not at all likely to assist Taiwan in submarine building"

Anonymous in Comments at 29/9/16 8:36 AM conveyed a Dr Kashin's views about the strong unlikelihood of Japan, the US and others providing submarine assistance to Taiwan. This is in useful contrast to my September 21, 2016 article Taiwan's Teadrop Style Future Submarine - Japanese Assistance?. 

Dr Kashin [1] a Russian defense expert, wrote in Sputnik News [article of Dec/09/2015, https://jp.sputniknews.com/japan/20151209/1290996.html in Japanese] that submarine technology transfer from Japan to Taiwan is highly unlikely. If you right-click mouse to translate Kashin's article you will see he said, along the lines:

Only the US can challenge China by anticipating the Submarine Project of Taiwan. The US could  obviously assist Taiwan in a joint project on combat and sonar systems. But, issues on the energy system and structural elements, which are diesel submarine specific, are difficult to solve. Also, in the US, there are very strong opponents against introduction of non-nuclear submarines. The opponents have blocked any investment or technological development for manufacturing non-nuclear submarines.

As Japan has many problems with China, the Japanese government will never make a decision which triggers a harsh, long-term, confrontation with the Chinese government. 

An indigenous Taiwanese submarine development and building project, if it drew from foreign technology, could possibly be implemented. If the US participated in the project as a major partner of Taiwan, the US would herself, draw huge criticism from the Chinese government. Possible partners with Taiwan, excluding Japan are France, Germany, Sweden, etc. 

Japanese submarines are too big for Taiwan. However, if a contract with Taiwan were drawn up  [by any assisting countries] it would be kept very secret.  

[1] Dr. Vassily Kashin has a Ph.D. in Political Science, is a senior research fellow at the Center for Comprehensive European and International Studies at the National Research University [one of Russia's top universities] - Higher School of Economics. He is also a leading research fellow at the Institute of the Russian Far East.

Anonymous & Pete

Submarine Noise

The following is an excerpt on acoustic quieting from Matt's excellent article February 3, 2015: Sea Denial: Analysis of the CSBA's Proposal The Case for Taiwanese Midget Submarines - Part I in Matt's website American Innovation.

Pete has added comments in [...] brackets.

Acoustic signatures for US and Russian submarines. [The Russian "Lead Ship Keel - 4th Generation SSN became the Yasen class. Of US subs "688" is Los Angeles SSN, 688I Improved Los Angeles, SSN-21 Seawolf class, NSSN Virginia class (Image Credit: Federation of American Scientists.)]

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Stealth, first and foremost, is the most critical aspect of an attack submarine as it determines the submarine's relative survivability and is a prerequisite to the submarine acting as an effective area denial, power projection, or ISR platform. 

Quieting technology has progressed steadily since the end of the Second World War with the advent of improved anechoic tiles, integrated electric drive systems (over mechanical), X-shaped stern control surfaces, pump jet propulsion systems (over conventional propellers), AIP technology, [elastic or dampner mounts for engines and other moving parts] etc. The acoustic signature of a submarine, which is measured in decibels, is an indicator of a submarine's relative detectability to passive sonar systems. The following is from the article "China's Anti Access Strategy: Submarine Force - Part I":

A decibel is "a unit used to measure the intensity of a sound or the power level of an electrical signal by comparing it with a given level on a logarithmic scale" (American English in Oxford dictionary, 2013). Decibels do not scale linearly. A 3db change is signifies a doubling power and a change of 10 db signifies the power increasing by a factor of ten. Therefore, the 636 Kilo class with an acoustic signature of 105 decibels is 10 times as loud as the 95 decibel acoustic signature of the Virginia class submarine.

The United States is widely recognized as fielding the most capable and stealthiest submarines with the Virginia and Seawolf class submarines. The following is from  Chinese Evaluations of the U.S. Navy Submarine Force by Andrew S. Erickson, William Murray, and Lyle Goldstein:

"Chinese observers are intensely interested in and closely follow other modern U.S. nuclear submarines, including the [Seawolf class SSN-21 USS Jimmy Carter, Seawolf}, and [Virginia class USS Hawaii (SSN-776)]. Highly detailed, full-page color photos of Seawolf- and Virginia-class submarines appear in China’s most prominent naval journals. These photos are usually accompanied by articles that imply an advanced state of technology and advanced acoustic quieting...

Chinese authors believe Seawolf possesses 'beyond-first-class performance' and is regarded as the most sophisticated and lethal submarine yet to go to sea, despite its 'tortuous development history'. The Chinese also respect Virginia-class submarines for their advanced technology and quietness...'Its acoustic signature is lower than that of the improved model of Russia’s Akula-class attack submarine and Russia’s fourth-generation attack submarine that will hereafter be in active service'. 

Another analyst, in discussing the Virginia class’s acoustic achievements, reports, 'The Virginia-class has been called the world’s quietest submarine,’ with a cruising sound level that is only '1/10 that emitted by a Los Angeles class boat pierside'. The construction techniques used to build Virginia and its sister ships also evoke respect'" 

The following acoustic signature figures are from Chinese Evaluations of the U.S. Navy Submarine Force and China’s Future Nuclear Submarine Force: [made into a Table by Pete]

Submarine Source	Decibels
Ocean background noise [1]	90 decibels
SSN-21 Seawolf class SSN	95 decibels
Virginia class SSN	95 decibels
Russian Improved 636 Kilo class SSK	105 decibels
Akula class SSN	110 decibels
Improved Los Angeles SSN	105 - 110 decibels
Type 093 Shang SSN	110 decibels
Type 094 Jin SSBN [2]	120 decibels

[1]. Regarding "Ocean background noise" or ambient noise - see Figure 1.       at http://www.nature.com/articles/srep00437 for noise levels (at sea) from natural/biological and Shipping Noise - yielding at least 90 decibels in 2001 and 2007. The 90 decibels appears more an average than a constant noise level everywhere. So submarines that can be very quiet in quiet ambient sea conditions can use their Passive Sonars to hear much more enemy activity over longer distances.

[2]. China’s Type 094 Jin SSBN is the loudest, too loud to go on regular patrol. In 2009, USN ONI listed the Type 094 as being slightly noisier than Project 667BDR (NATO reporting name Delta III) from the late-1970s, some of which were in service through 2015 with the Russian navy.]

 Relative detectability of Russian and Chinese diesel and nuclear powered submarines. Image Credit: US Office of Naval Intelligence, 2009. 

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Also see:

Source: Worldwide Submarine Challenges 1996, Office of US Naval Intelligence via Jeffrey Lewis's "China's Noisy New Boomer"  at Arms Control Wonk, November 24, 2009  https://www.armscontrolwonk.com/archive/202544/chinas-noisy-new-boomer/

 

Indonesian Visions, Straits and Fluctuating Submarine Numbers

Map A. Sea Depths The shallowness (less than 200 meters) of water surrounding most Southeast Asian nations has, to a degree, limited the takeup of submarines. Shallow water is often encumbered by reefs, many islands and larger landforms that define straits and narrows. There is also heavy ship traffic through many of the straits. These hazards are difficult and dangerous for submarines to move through. (Map courtesy US Centers for Environmental Information).

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Indonesia currently has two mature age Type 209/1300s, KRI Cakra (401) and KRI Nanggala (402), both commissioned in 1981. 

To remedy this situation Indonesia has on order two Improved 209s built in South Korea, named/numbered (KRI Nagabanda (403) (also called KRI Nagapasa (403). Which is correct?) and KRI Trisula (404). These are likely to be commissioned in 2017 and 2018 respectively. 

A third Improved 209, KRI Nagaransang (405), is likely to be built at PT PAL (Surabaya), Java, Indonesia and perhaps commissioned in 2020 or later.

There have been many reports over the years that Russian and/or DCNS (French) submarines are also being considered. It would probably make much more sense to build additional 209s at PT PAL.

  

Indonesia may eventually want more than two submarines. The Indonesian Navy has more than 13,000 islands, seas and straits to oversee. Indonesian vessels have had confrontations with Chinese Coastguard vessels at the Natuna Islands at the northern end of the Indonesian Archipelago Also in the northern Archipelago Indonesia has experienced occasional confrontations with Malaysian surface vessels concerning Ambalat undersea oil resources (see Submarine Matters article).

 Map B. the Straits - If the 2.8km narrow and 25m shallow Malacca Strait were blocked the Sunda Strait, as shallow as 20m, is inadequate to take up much ship traffic. The Lombok Strait, 20km wide and up to 250m deep is better proportioned to handle large ships.  

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Overall strategic visions are conveyed to the public from the highest level possible - which is the presidential. In a fine commentary Dharma Agastia records some of Indonesia's broad strategic visions requiring up to 12 submarines. These include visions from:

- former Indonesia President Susilo Bambang Yudhoyono, with his Minimum Essential Force 

  (MEF) in the Strategic Defense Plan (Renstra), and

- current President Joko “Jokowi” Widodo who, in 2014, held a “Global

  Maritime Fulcrum” or Axis vision.

Disagreements between Indonesian factions are likely to exist behind the presidential visions. There are likely to be many attitudes in the Indonesian Navy, broader defence and industry development bureacracies about how many more than 2 or 3 submarines can be bought, maintained and crewed.

At one end of the spectrum Indonesia may only have one crew to operate just one of the current Type 209s (KRI Cakra (401) or KRI Nanggala (402)) at any one time. Meanwhile the nucleus of another crew may be in South Korea training to use the first Improved 209 (KRI Nagabanda (403)).

Another faction may want the 3 Improved 209s +  two extra subs (for a total of five).

Others, seem to want a total of twelve submarines by the late 2020s for example 3 Improved 209s + 9 other subs (of Russian or French origin). Such a faction may be of submarine service origin because if the Indonesian Navy operated twelve submarines there may be no money or men left in the Navy for major surface ships.

Twelve might be justified by: expanding strategic responsibilities; Indonesia’s rising GDP enabling it to buy more; a return to Indonesia’s submarine glory days when it had twelve Russian supplied Whiskey class submarines (late 1950s to mid 1960s) used in the liberation of West Iran from the Dutch in 1962. The Indonesia Navy would also be mindful of the Australia's (perhaps excessive and unrealistic) plan to build 12 large SSKs from the late 2020s. 

In low level "warfare" confrontations submarines might produce a feeling of doubt in opponents. Submarines are always fine intelligence collection platforms. The central government can also issue orders to submarine commanders on whether it is necessary to escalate actions. 

Pete

Submarine Sonar Upgrades - Virginias, Collins and Shortfins

Australia's Collins class and future Shortfin class subs are likely to benefit from the US system of software-hardware sonar upgrades. This is within the broader sensor and data technology of the AN/BYG-1 combat system. It was announced on September 30, 2016 that Lockheed Martin would integrate the combat system into the Shortfin.
-  Bringing up US-Australian sonar systems follows some Anonymous comments on Russian MGK sonar systems. There seems to be no rigorous way of comparing US and Russian sonar claims.

Virginias, Collins and future Shortfins are relatively large submarines with large, higher power, bow sonars to detect targets at a longer distance.

 "The AN/BYG-1 modernization program develops commercial-off-the-shelf (COTS) software and hardware upgrades to integrate improved tactical and weapons control capabilities for multiple submarine classes. The program integrates the tactical control, weapons control, and tactical network subsystems. The AN/BYG-1 is installed on the U.S. Navy's Los Angeles, Seawolf, Virginia and SSGN-class submarines, as well as on the Royal Australian Navy's Collins-class submarines."

Wiki describes it as https://en.wikipedia.org/wiki/Virginia-class_submarine#Improved_sonar_systems:

Sonar arrays aboard Virginia-class submarines have an "Open System Architecture" (OSA) which enables rapid insertion of new hardware and software as they become available. Hardware upgrades (dubbed Technology Insertions) are usually carried out every four years, while software updates (dubbed Advanced Processor Builds) are carried out every two years. Virginia-class submarines feature several types of sonar arrays.^[55]

• BQQ-10 bow-mounted spherical active/passive sonar array^[55][56] (Large Aperture Bow (LAB) sonar array from SSN-784 onwards)

• A wide aperture lightweight fiber optic sonar array, consisting of three flat panels mounted low along either side of the hull^[57]

• Two high frequency active sonars mounted in the sail and bow. The chin-mounted (below the bow) and sail-mounted high frequency sonars supplement the (spherical/LAB) main sonar array, enabling safer operations in coastal waters, enhancing under-ice navigation, and improving anti-submarine warfare performance.^[58][59]

• Low-Cost Conformal Array (LCCA) high frequency sonar, mounted on both sides of the submarine's sail. Provides coverage above and behind the submarine.^[60]

Virginia-class submarines are also equipped with a low frequency towed sonar array and a high frequency towed sonar array.^[61]

• TB-16 or TB-34 fat line tactical towed sonar array^[62][63]
• TB-29 or TB-33 thin line long-range search towed sonar array^[62][63]

Presumably the Collins benefits from the same hardware/software update system? The Collins (see right sidebar) utilises a: "Thomson Sintra Scylla bow and distributed sonar arrays, Thales SHORT-TAS towed sonar array and Thales intercept array".

Pete

Swedish Submarine Industry Neutralised by Russia?

Features of the the Swedish Navy's future A26 (hugely expanded here). The A26 is the only submarine left featuring and marketing the horizontal multi-purpose lock (HMPL). This is what Saab calls the "multi-mission portal" (above and below). (Digarams courtesy).

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Russia's Sputnik News has reported on the trouble Sweden's Saab is having selling submarines to Poland, Norway, the Netherlands and any other customer countries. Russia may be happy there are cracks between Sweden and the NATO countries, given there is occasionally popular support within Sweden for joining NATO.

Saab has been unable to sell its latest future submarine, the A26, or used smaller submarines, to other countries. With only the Swedish Government's order for two A26s (for delivery by 2022) the fixed costs of development for such a small production run may be too steep. Sweden-Saab would therefore prefer to share the development costs with customers. 

If there are no foreign orders delivery of the A26s may be delayed to 2024 or longer.

The Swedish Government ordered the two A26s in March 2015. Saab may have hoped that the Swedish Government would follow up with orders for three additional A26s as replacements for the 3 existing Gotland class. Instead the Government decided on midlife upgrades for 2 of the Gotlands (HSwMS Gotland and  HSwMS Halland) by 2020. Those 2 Gotlands could then be operational for 10-15 years, thus delaying a need for additional A26s for 10 or more years. 

The Swedish submarine service also operates 2 Sodermanland class which will be retired once the A26s join the service. Resale of the 2 retired Sodermanlands (which boast AIP) remains a possibility. 

The sale of Sweden's traditional submarine builder, Kockums, to German interests in 1999 weakened Kockum's competitiveness.

- an existing customer, Singapore, had been happy with 4 ex-Swedish Navy Challenger class and 2 Archer class). But in December 2013 Germany's TKMS, which owned Kockums, engineered a deal with Singapore which shifted Singapore's new submarine choice to a new German built submarine type, the TKMS 218SG.

- in 2014 Sweden, through Saab, regained control of Kockums. Unfortunately another existing Kockums customer Australia (that had bought 6 Kockums designed Collins class) was not interested in buying new submarines from Kockums.

Now, in 2016, with the increasing threat from Russia, there has been an increase in NATO solidarity among Baltic NATO countries including Poland and Norway. These two countries have strongly expressed an interest in buying from NATO countries that build submarines (effectively Germany's TKMS or France's DCNS). In June-July 2016 an operational alliance deal between Poland and Germany further increased the chances of a German sale.

There may be some concern that Sweden may be more susceptible to Russian pressure than "great NATO  powers" Germany and France. 
-  this is because non-NATO, neutral Sweden is only a small-middle sized power. Its wholey Baltic position also makes it more vulnerable to the Baltic's nuclear superpower, Russia.

Suspicions may exist that Sweden may have been further neutralised by Russia. This arises from highliy publicised sightings, near Sweden's capital Stockholm in late 2014, of what Sweden first described as Russian submarine activity. Then Sweden backtracked saying the sightings (which included photographic evidence) were not Russian submarines at all.  Was this backtracking due to quiet Russian pressure?

A concern would be if there was a prolonged period of NATO or Swedish tension with Russia. Would Sweden provide submarines, a steady flow of spare parts and would Sweden enable the combat system fitout of long range land attack cruise missiles desired by Poland? Russia would be the logical target for such missiles. 

Another possible A26 customer is the Netherlands. In early 2015 there may have been agreement between Saab and the Netherlands shipbuilder Damen to consider building A26s. I suspect the Netherlands is also tipping in a pro-NATO buying direction - meaning from Germany or France, and  not from Sweden.

The mighty F-35A.

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Is Gripen vs F-35A still an issue?

Russia's Sputnik News also notes, September 30, 2016, that Norway did not buy Saab's Gripen fighter. According to Sputnik Saab is still hoping to sell Gripens to Poland and the Netherlands. Or have both Poland and the Netherlands already chosen the F-35 and Sputnik is just trying to stir up ill-feeling against the US and the F-35? 

Pete