November 5, 2015

Chinese and US Submarines Likely Kept Watch on USS Lassen



China's built-up, militarised island of Subi Reef is just above the center of the map above. With the US  informing China beforehand, a US destroyer, USS Lassen, approached close to Subi on October 26, 2015. The South China Sea (see inset map above) stretches from Taiwan in the north to Borneo island and Singapore in the south, Vietnam in the west to the Philippines in the east. That sea's main trouble spots are the Paracel Islands and Spratly Islands (which includes Subi Reef).

China is flexing its naval power by claiming that large areas of the South China Sea belong to it. China believes its right is strengthened by a rather weak argument that because the sea in question is most commonly called "South China Sea" it belongs to China under international law. 

The US has been the most active country to reject such a Chinese claim. The US is demonstrating the right of ships and aircraft to pass close to islands claimed by China by conducting freedom of navigation operations (FONOPs). 

Submarines cannot show the flag unless running on the surface (at a major disadvantage) or sitting in port. But subs can precede, follow up and protect surface ships that are showing the flag.

When USS Lassen (DDG-82) embarked on her freedom of navigation operation (FONOP) on  October 26, 2015 she “was accompanied by two [US] maritime surveillance aircraft, a P-8A Poseidon and a P-3 Orion. Pentagon officials leaked information about the FONOP before it took place as well as after it was completed, but refrained from speaking on the record about the mission.

Lassen's FONOP took her within 12 nautical miles of Subi Reef. It is likely that Lassen was preceded by a US SSN from Submarine Squadron (SUBRON) 15, Guam, and possibly another SSN from that SUBRON followed her. These submarines, keeping watch with their extensive passive sonar and intercept systems, protected Lassen from surprises. Surprises would be mainly in the shape of Chinese surface warships and/or submarine activities. 

China would anticipate the presence of US submarines for such politically and strategically important operation.

China for its part may have posted some Yuan class submarines along the previously advised route that Lassen took. I suspect Yuans were used because they would be China's best equipped subs to move into the Subi Reef area and wait for the Lassen on October 26. As the Yuan's have air independent propulsion (AIP) and other advances they would be better placed to discretely collect technical intelligence from the Lassen, other US ships and SSNs as these US ships/subs passed by..

DETAILS ON THE US SUBS AND USS LASSEN

Submarine Matters, on June 17, 2015, reported on Submarine Squadron (SUBRON) 15 which consists of 4 SSNs serviced by large shore installations and submarine tender USS Frank Cable all based in Guam.  SUBRON 15 supports the activities of the Seventh Fleet headquartered in Yokosuka, Japan. At Yokosuka is Destroyer Squadron 15 which includes USS Lassen (DDG-82).

So although the Seventh Fleet is based in several far-flung places its powerful forces come together for key activities like the FONOP near Subi Reef.

It is unlikely that Australia or Japan will run their own FONOPs for the foreseeable future.

SUBI REEF

As indicated by Submarine Matters on September 24, 2015 China is building up several South China Sea islands into military bases very quickly. The islands can host air and naval bases and also long range intelligence sensors including radars. The islands it is building up most rapidly appear to be Mischief Reef, Fiery Cross Reef and Subi Reef. 


Subi Reef, seen in three photos below, is being rapidly built up into an air and naval base - initially using sand dredging for landfill. The photos below, dated April 2015, June 2015 show rapid progress by August 2015 Subi. The reef-island has almost a completely enclosed harbour. Port facilities and a 3,000 meter airstrip will soon be built.


(Satellite image above courtesy Victor Robert Lee and Digital Globe via The Diplomat
---

Subi Reef (above) 2 months later in August 8, 2015 (Satellite image courtesy CSIS/AMTI via Reuters)
---

China is effectively claiming that improving or building on islands is really a right of defence which (in China's mind) spreads out to a much broader territorial right around the islands. The air and naval bases that will eventually be built will also provide practical weapons to defend China's purported rights and arguments.

China's activities in the South China and East China Seas contribute to international tension. Tension that is drawing such countries as Japan, Australia, Vietnam, the Philippines, India and, of course, the US, closer together.

Pete

18 comments:

Anonymous said...

China clearly violates international law. We cannot accept such a way.

Anonymous said...

Hi Pete

I think that 27SS or 28SS will equip additional 240 cell modules in (10) LOx tanks/cold boxes [1]. This means these two submarines have 720 cell modules as three groups, 3-4.5 times longer submerged range [2] and exceptional high speed as a conventional submarine [3] if they have a new generation system and motors.

[1] NDS F8016B “General rules for design of equipment with small stray magnetic field”, 5.3”Arrangement of main batteries for submarine” specifies that submarine generally equips with directly connected 240 single cells as a group.
[2] I assumed energy density of LIBs is 2-3 times higher than current LABs.
[3] If we adopt simple cubic rule between speed and power, maximum speed will be estimated to be 29-33knot/h for extremely short period. I think actual speed will be lower than estimated value, but still enough high.

Regards
S

Nicky said...

Hi Pete,
Funny how China says their submarine was following the US Aircraft carrier but the US has a Fast Attack SSN following the Chinese submarine behind his baffles. It just seems like China doesn't understand that the US never sails a ship alone and always has a SSN guarding their underwater.

Nicky said...

Hi Pete,
Check out this story. Looks like Brazil has Budget issues on their Nuclear Submarine program.

http://www.navyrecognition.com/index.php?option=com_content&task=view&id=3223

Peter Coates said...

Hi S

Thanks for those additional battery-cell figures. I will do a new article next week that updates Soryu diagram http://gentleseas.blogspot.com.au/2015/10/diagram-inside-soryu-submarine.html

Additional information on how many hours 27SS or 28SS might be able to remain submerged would be interesting.

Regards

Pete

Peter Coates said...

Hi Nicky [at November 6, 2015 at 4:53 AM]

Yes it is interesting that probably a US SSN, patrol aircraft and probably the carrier's escorts were able to determine the Chinese sub was a Kilo. Watching the watcher http://edition.cnn.com/2015/11/04/politics/chinese-submarine-u-s-aircraft-carrier-japan/

Regards

Pete

Peter Coates said...

Thanks Nicky [at November 6, 2015 at 7:30 AM]

For http://www.navyrecognition.com/index.php?option=com_content&task=view&id=3223 on Brazil slowing down its nuclear submarine program. Brazil has been very quiet about PROSUB milestones being reached. The slowdown will also be a blow to DCNS revenue schedule.

Brazil is like Australia in being sensitive to drops in prices and amounts of energy and mineral exports (iron ore to China is a big money earner for Brazil and Aus). All due to China's economic slowdown.

I'll update http://gentleseas.blogspot.com.au/2015/03/brazil-new-submarine-prosub-program.html in an article next week.

Regards

Pete

Anonymous said...

Hi Pete

In the previous comment (November 6, 2015 at 12:18 AM), I assumed specialty maximum power of 18,000-27,000kW@15min for propulsion motors operated by LIBs (5900kW@15min for current LABs Soryu). In the case of high power propulsion motor of conventional submarine, adverse effects such as increased cooling power and friction should be considered: i) elevated temperature at silent mode operation where auxiliary motor for water cooling is stopped, and ii) increased cooling energy and friction loss which especially require extra energy. I think maximum power of motors and maximum speed may be controlled at relatively lower level (ex. 12,000kW, 25knot@1hour). LIBs can supply enough power to propulsion motors quickly, because output rate of LIBs are much higher than that of LABs.

Where, maximum speed means maximum seed in hour (18knot@1h for current Soryu), and specialty maximum speed means maximum speed at over load (20knot@15min).
Regard
S

Nicky said...

Hi Pete,
That's why the US Never sails a ship alone. It's always followed by a Fast attack SSN and it's most likely had they Chinese Submarine and ship on it's Sonar and some Sonar Tech had it's eye's on the target and weapons officers getting the torpedo's primed. It's why almost every US carrier and Amphibious ready group has a US Submarine on watch and guarding the US carrier and Amphibious ready group's underwater.

Nicky said...

Hi Pete,
I also think Brazil is at a down turn in the economy. Which is why I think they should keep the AIP Scorpene going while slowing down the Nuclear scorpene.

Anonymous said...

Hi Pete

I correct comment (November 6, 2015 at 9:34 PM)

Before correction
i) elevated temperature at silent mode operation where auxiliary motor for water cooling is stopped.
After correction
i) elevated temperature at silent mode operation where auxiliary motor for fan and oiling pump for bearling are stopped.

Regards
S

Peter Coates said...

Thanks S

For your comments at November 6, 2015 at 9:34 PM and November 7, 2015 at 11:46 AM .

I shall place them in the article next week.

Regards

Pete

Peter Coates said...

Hi Nicky [at November 7, 2015 at 1:27 AM]

Yes US SSN's would have frequent, unsung, escort duties.

Regards

Pete

Peter Coates said...

Hi Nicky [Nov 7, 1:28 AM] on Brazilian and Indian Scorpenes

Apparently the Brazilians have an automatic rule that if their government does not reach budget targets year-on-year spending is withheld for some defence items. Such withholding might be happening to their nuclear sub project.

On AIP http://www.defenseindustrydaily.com/brazil-france-in-deal-for-ssks-ssn-05217/ indicates:

"In 2008, Brazil and France signed an agreement to build 4 diesel-electric submarines (SSK), and provide assistance in developing and fielding the non-nuclear parts of 1 nuclear fast attack submarine (SSN). Key specifics, such as the presence or absence of SSK Air Independent Propulsion technologies, have yet to be made public, but the terms of the agreement leave the possibility open."

DCNS's problem of the AIP gap seems to be happening with Brazil and perhaps the unbuilt Indian Project 75 Scorpenes. The Gap is where DCNS MESMA (first generation) AIP is no longer attractive to customers. Customers are interested in DCNS's not yet mature fuel cell (second generation) AIP. The latter AIP may be retrofitted into the 4 conventional Brazilian Scorpenes and some of the Indian Scorpenes (rebadged as "DRDO" AIP).

Regards

Pete

Anonymous said...

Hi Pete

Reduction of stray magnetic field must be considered in cell arrangement and cell-to-cell connection according to NDS F8016B. Rules of the arrangement and the connection are as follows: i) width of each column of cell module should be the same, ii) numbers of each column are desirably multiples of four or must be at least odd number, iii) desirable numbers of cell modules in a column are multiples of four, iv) polarity cancellation of a pair of neighboring columns should be conducted by cross connection of these columns, and so on.

Number (=200) of column per group was decided based on these rule. Logically speaking, if these rules are satisfied, other arrangements such as three groups of 240 columns or four groups of 160 columns are possible, I think.

Regards
S

Anonymous said...

Correction of comment (November 7, 2015 at 11:43 PM)

Before correction
Number (=200) of column per group was decided based on these rule. Logically speaking, if these rules are satisfied, other arrangements such as three groups of 240 columns or four groups of 160 columns are possible, I think.

After correction
Number of cell module per group (240=20columns x 12 cell modules) was decided based on these rule. In this case, number (20) of column satisfies rule ii) (20=4 x 5) and number (12) of cell module in a column satisfies rule iii) (12=4 x 3). Logically speaking, if the rules are satisfied, other arrangements such as three groups of 24 columns or four groups of 16 columns are possible, I think.

Nicky said...

Hi Pete,
Maybe that's why Brazil is looking at building the AIP version of the Scorpene to supplement the Nuclear version. Which I think they should have done in the first place. If the Nuclear version is going to take a lot longer, then the AIP version is what they should be looking at.

Peter Coates said...

Hi Nicky

Difficult to say whether Brazil has been seeking AIP given AIP's extra cost, weight, some dangerous chemicals and heat.

DCNS ability to facilitate non-nuclear Scorpene and (everything but reactor drive) nuclear solutions makes DCNS a one-stop-shop for Brazil.

Also nuclear is a type of "super" AIP in itself - making a Brazil (with enventually a few SSNs in 35 years time) less likely to want to bankroll conventional AIP.

Regards

Pete