August 1, 2016

China's current SSBNs Too Limited to Be Effective - Part One

In Part One I argue China's 4 x Type 094 "Jin class" SSBNs are currently too limited to be effective due to:

-  geography - very shallow water around the actual SSBN Base at Yulin, Hainan Island then a
   restricted South China Sea operating area, then sea depths too shallow especially south of the
   Natuna Islands (see Map B), 
-  094s are known to be too noisy to be stealthy
-  their commanders and crews lack operational SSBN patrol experience
-  the JL-2 SLBMs missiles with an estimated range of up to 8,000 km are too limited to hit US
   mainland targets from the protected (near Chinese) waters the SSBNs have to operate in.  
-  China's military-political command and control system may not be flexible enough to allow SSBN
   commanders to carry armed JL-2s or deliver the codes commanders to launch. Basically against
   Communist Party's tight control of military.


Map A - The inner "J" indicates China's "First Island Chain" is where China's four Type 094 SSBNs are effectively restricted. These SSBNs are based in China's South Sea Fleet bases (Map A above) specifically at Sanya/Yulin Naval Base on Hainan Island. Moving outside that chain would take SSBNs away from protective Chinese aircraft and these SSBNs would need to pass between island narrows where undersea sensors (see Map C) and enemy aircraft, surface craft, SSKs and SSNs are likely to be waiting.

Also the following could intervene into the South China Sea to destroy Chinese SSBNs: enemy aircraft and submarines from Vietnam, Singapore (passing through the Philippines) also submarines further out from Guam, Japan, Australia, Hawaii and US West Coast. 

Map B - The water (ideally 1,000+ m deep) restricts the already narrow South China Sea operating area and the sea becomes radically too shallow (less than 100m deep) south of the Natuna Islands.

Useful water depth for a submarine could be all the way down to "crush depth" which may be 1,000+ meters for a Chinese SSBN. While deep water past crush depth (maybe 1,000 meters) may not benefit a submarine there is a correlation between depth and usable surface area.

The lack of adequate 1,000+ meter depth in large areas of the 3,500,000 square kms South China Sea may limit usable SSBN operational area to less than 2,000,000 square kms.

This reduced area to cover with sensors makes it easier for the US to lay seafloor or tethered sensors (including SOSUS) in and around that reduced usable SSBN area.

Tethering means that even in a 2,000 meter deep area a sensor with a 1,200 meter long tether (from the seafloor) would be very useful detecting Chinese SSBNs.


Map C - Map depicts some of the likely Western SeaWeb undersea sensor array positions. Chinese, Russian and North Korean submarines and surface vessels are likely to be of most sensor interest. (Map from page 54 “Map 4. The US ‘Fish Hook’ Undersea Defense Line” of Desmond Ball and Richard Tanter, The Tools of Owatatsumi Japan’s Ocean Surveillance and Coastal Defence Capabilities (2015, ANU Press) http://press-files.anu.edu.au/downloads/press/p309261/pdf/book.pdf?referer=444

FURTHER COMMENT

I've made several generalisations that might be disputed by reading of other websites and documents including:

-  http://thediplomat.com/2015/05/strategic-warning-and-chinas-nuclear-posture/

-  US DoD's "Chinese Military Power 2016") large PDF at:
  http://www.defense.gov/Portals/1/Documents/pubs/2016%20China%20Military%20Power%20Report.pdf


-  rightwing US and most Taiwanese websites should be treated with caution as they might tend to exaggerate China's SSBN "threat" as being serious and current.

China may take 25 years to attain the quality of US, UK and French SSBNs of today and to develop a JL-3 or a JL-4 SLBM with the range and accuracy of the Trident II SLBM.

Pete

18 comments:

Anonymous said...

Whatever the effectiveness of their SSBNs, Chinese belligerence continues:


Major Chinese state paper calls for a military strike on
Australian ships that enter the South China Sea:

"China's state-run Global Times has published an editorial attacking Australia for
supporting the recent international ruling on China's activities in the South China
Sea and called for strikes on any Australian ships which might undertake "freedom-
of-navigation" activities in the region."

See:

http://www.businessinsider.com/china-state-paper-calls-for-military-strike-on-australia-ships-entering-south-china-sea-2016-8

Ztev Konrad said...

Since for all submarines they are effectively limited to 300- 500m depth sometimes less, the water being deeper has no tactical use. In reality, its easier for sonar to find a submarine where the depth is over 2000m. Only advantage of open ocean is the larger surface area, not the depth

Peter Coates said...

Hi Anonymous

Governments produce military propaganda through the media or through military officials.

The Chinese Government would allow or instruct the Global Times to write about an extreme, unviable comment of military action against Australia.

This is much like the US Government allowing some US Admirals to say the US should be prepared to go to war with China over the South China Sea.

China then responds by having a junior Admiral or Captain say "yes China should defend itself".

And so the verbal sparring goes on.

Pete

Peter Coates said...

Hi Ztev

Useful water depth for a submarine could be all the way down to "crush depth" which may be 1,000+ meters for a Chinese SSBN. While deep water past crush depth (maybe 1,000 meters) may not benefit a submarine there is a correlation between depth and usable surface area.

The lack of adequate 1,000+ meter depth in large areas of the 3,500,000 square kilometres* South China Sea may limit usable SSBN operational area to less than 2,000,000 square kms.
* https://en.wikipedia.org/wiki/South_China_Sea

This reduced area to cover with sensors makes it easier for the US to lay seafloor or tethered sensors (including SOSUS) in and around that reduced usable SSBN area.

Tethering means that even in a 2,000 meter deep area a sensor with a 1,200 meter long tether (from the seafloor) would be very useful detecting Chinese SSBNs.

Regards

Pete

Ztev Konrad said...

The bathymetry on the map shows plenty of water over 1000m in SCS. ( darker shades blue).
This discussion about the best depths for submarines to operate indicates deep oceans are not useful either
http://fas.org/man/dod-101/sys/ship/deep.htm
"The Best Depth for a submarine to avoid detection by a hull-mounted sonar is conventionally regarded as the Sonic Layer Depth plus 100 meters. This assumption is based on the premise that maximum downward refraction of sonic energy will occur at the depth of the strongest minimum sound speed gradient"

"Below about 500 meters, all of the world's oceans are at about 34 F. "

MHalblaub said...

Dear Pete,
Are you really sure about the 1,000 m?

In my eyes 1,000 ft are more realistic.

MHalblaub said...

Dear Ztev Conrad,
Depth is good to outrun US piston engine driven Mark 48 torpedoes. The deeper the less power a piston engine can provide. At a certain depth the chemical reaction provides just the same pressure as rhe surrounding sea: dead slow!

Put a plug in your cars exhaust pipe and try it.

Warning!
Diesel engines may blow out the plug or ruin another weak part of the exhaust system.

Batteries need no exhaust systems.


Regards,
MHalblaub

Peter Coates said...

Hi MHalblaub [2/8/16 5:20 PM]

1,000m being a rounded ballpark magnitude.

With 400m = 1,200 feet being a possible operating depth. Crush around twice? Depends.

We are talking ASW signals not just raw depths for the SSBN:
For US sensors the seafloor at 1,000m might be marginal. Tethered from 1,000m a bit better.

Go considerably deeper than 1,000m then:
- seafloor sensors become very faint, and
- tethered problematic.

Regards

Pete

Peter Coates said...

Hi Ztev [2/8/16 3:03 PM]

Main point being the South China Sea is restricted area-wise even out to unrealistic minimum depth of 200m and South China Sea is likely surrounded by Western SeaWeb sensors.

So those noisy Chinese SSBNs have trouble breaking out into the Indian or Pacific Oceans - the open oceans where SSBN commanders prefer to be.

Regards

Pete

Anonymous said...

Hi Pete

The reshuffling of the Cabinet of Japan will be conducted tomorrow. Madam Tomomi Inada will be the next Minister of Defense. Madam Inada is a potent hawk politician (https://en.wikipedia.org/wiki/Tomomi_Inada). PM Abe highly appreciates her as a future PM candidate.

Regards
S

Josh said...

The PLAN boats might well adopt a policy of always keeping one outside the first island chain where they have more room to maneuver. A SSBN putting to sea is always at risk of initial detection during deployment - US boats regularly tracked Soviet SSBNs as they left their ports, waiting just inside international waters. The trick would be to attempt to loose the tail on the other side of any detection system along the first and second chains, putting the boat in range of more targets as well as creating more space to hide.

Due to the noise and communications issues associated with PLAN SSBNs I don't think this goal very realistic at this time(or indeed any reliably safe sub sorties outside the first chain without tails) but it still probably represents the optimal position to train for in the mean time.

Its also worth noting that PLAN boats might currently be more focused on Russia and India as potential competitors, neither of which has a significant ASW capability in the SCS.


Cheers,
Josh

Anonymous said...


IMHO the 2nd Artilerry will always the primacy over the PLAN's SSBN. The road-mobile DF-31/41 already have the range to pound Western CONUS/ all of AUS and probably cheaper to buy/operate and easier to control.

The Western Pacific is just a tough neigbourhood, where the PLAN might achieve a local/tactical supremacy, but never a strategic one below the water-surface.

BTW Pete, are you familiar with sinodefenceforum.com?

Team Eurowussies

Peter Coates said...

Hi S

Choice of female politician Inada as Defence Minister seems quite possible.
http://www.japantimes.co.jp/news/2016/08/02/national/politics-diplomacy/ishiba-expected-decline-cabinet-post-can-focus-bid-succeed-abe/#.V6FaFvl97b0

Australia first female Defence Minister, Marise Payne, still holds that position.

Germany also has a female Defence Minister I think. I wonder when the US will appoint a woman Defence Minister?

Regards

Pete

Ztev Konrad said...

The US navy MK48 uses as radial piston engine described as cam-piston with a swash-plate powered by an oily liquid 'Otto fuel' which means it contains its own oxidiser ( and is relatively safe).
"The MK 46 cam-piston engine is essentially a constant torque output device, with the torque dependent on combustion pressure and back pressure. Fuel pump output pressure (combustion pressure) is controlled by an internal regulator that is referenced to sea pressure to maintain nearly constant shaft output torque as the sea pressure increases with depth. Constant vehicle speed is then maintained at all running depths."

Very good description and schematics shown here ( near bottom as its a long page)
http://www.douglas-self.com/MUSEUM/POWER/unusualICeng/axial-ICeng/axial-IC.htm#tor

Interestingly the engine can create gas pressures of 3600psi. An easy comparison of water pressure at depth for 1000m gives 1475psi.

Peter Coates said...

Hi Josh [at 3/8/16 3:42 AM]

I agree that “Due to the noise and communications issues associated with PLAN SSBNs I don't think this goal very realistic at this time”

So as I argued it might take 25 years for PLA-N SSBNs (and more distant covering PLA-N SSNs) to be sufficiently quiet to be discrete.

The geographic positioning of available Chinese ports puts China at a major disadvantage compared to the SSBNs of nearer open ocean SSBNs of UK, US, France, Russia and to an extent India.

As I’ll argue in the next article China needs new base territory to have more of a chance to lose tails.

The IRBMs and ICBMs in the center of China of course can hit Russia and India over the Chinese border but PLA-N SSBNs will have that special, ideally secure, second strike advantage. As you say Indian and Russian ASW forces are not assumed to be strong in the South China Sea.

Regards

Pete

Peter Coates said...

Hi Team Eurowussies [at 3/8/16 7:37 AM]

The increasingly accurate US, Russian and Indian ballistic missiles make silo based Chinese missiles increasingly vulnerable.

Improved US, Russian and Indian sensors make road and rail mobile Chinese ballistic missiles more vulnerable.

This is why all 9 nuclear weapon states are increasing using ballistic missile submarines as the preferred first and second strike nuclear missile platforms.

Yes I keep an eye on sinodefenceforum.com now and then. Everyone could spend all their time reading it (and other mega forums) and adding comments on all the sub photos that are spotted and duly repeated on the forums.

Regards

Pete

Peter Coates said...

Hi Ztev [at 3/8/16 1:28 PM]

Further to the sources you’ve located, another source indicating the US (with its Mark 48) is not forgetting deep diving Chinese and Russian subs is https://en.wikipedia.org/wiki/Mark_48_torpedo#Sensors_and_improvements

“The Mk48 Mod 7 Common Broadband Advanced Sonar System (CBASS) torpedo is optimized for both the deep and littoral waters and has advanced counter-countermeasure capabilities.”

Where MHalblaub states/implies the US has somehow, for some reason, neglected deep diving enemy subs, one just needs to recall the Soviet Alpha class in the 1970s which were calculated to have crush depths as deep as 1,300 meters – see https://en.wikipedia.org/wiki/Alfa-class_submarine#General_characteristics .

So (responding to MHalblaub) I don’t think US heavyweight torpedo and bottom rising mines/lightweight torpedos designers would have ignored (are ignoring) the potential depths of opposing submarine forces.

Also if ignorance was happening then French, Italian and German torpedo sellers would loudly be trumpeting the alleged Mark 48 depth deficiency and claiming their Euro torpedos should be bought instead.

Regards

Pete

Josh said...

As far as I know the major short coming of using the swash plate engine / otto fuel of the mk48 is noise generation. I believe speed, range, and depth were all considered very sufficient. Spearfish is the only weapon I know of that is considered faster in open source short of unguided super cavitating rockets. Speed and depth were increased with the ADCAP version in the 80's (I believe this was also labeled Mod 6). CBASS/mod 7 seems to be a catch all weapon upgrade for all environments that (at a guess) sacrifices cost per weapon for inventory standardization.

Cheers,
Josh