Sub Briefs or what every armchair sub-driver should know.

[miletus12]

Republic of Korea wants to imitate Japan and China.



They are the "Me Too!" navy in Northeast Asia.

[miletus12]

This version of the P-8 Poseidon is clearly derated, but it is designed to go after AIP boats as well as PLAN platforms.

India appears to be using France as its other naval aviation partner. The USG bumped up the order limit to 14 improve the Indian Navy coverage. The I variant includes antiship targeting capacity. India wants theirs to go anti-ship as well as anti-sub.

[miletus12]

Here is a topic from Covert Shores.



The differences: summary; the speed bands are the clear delineators. At high speed screws are better and more efficient for shove. At low to moderate speeds, pumpjets are much more efficient for shove and are a lot quieter.

[miletus12]

The Littoral Combat Ship was / is a disaster. What will be the fix?

[miletus12]

DDX is going to be a disaster.



Why are torpedoes on submarines almost all ~53 centimeters in diameter?

Bliss Leavitt actually set the standard in 1910. The USN wanted to sink (British) battleships.

Exceptions to the 53cm tubes.

The French went to 55cm diameter to match Bliss Leavitt. The French 40cm was to sink freighters. 55cm after WWI was used against warships. Post WWII, in order to make sales internationally, the French adopted the 53.3cm universal standard. 

The Russians went for 65cm torpedoes around 1975 to sink American aircraft carriers.

The Russians have abandoned the 65cm. It did not work.

The Americans have 66cm tubes in the Seawolf. It was desired to carry large missiles, not torpedoes. The 53cm torpedoes (Mk48s) would swim-out of the 66cm tubes. There may be liners, (guide studs actually), but those are not necessary for swimouts.

What is not mentioned are US 48.25cm torpedoes which were the norm for much of the 1950s and 1960s.

These may be making a comeback as the USN wants to up its weapon loadouts on its submarines. My guess is that one could see a 33cm torpedo.

[miletus12]

Things are not going well in the USN. Sick sailors and sick ships.

Own opinion is that failure starts at the top. The fleet is also losing 9% of its surface combat power within the next 2 months. Not good.

[miletus12]

"Olympic" Class submarine?

www.scmp.com/news/china/military/article/3166756/facebook-video-new-chinese-submarine-gets-experts-tongues

Video posted on Facebook group ‘Comments on the PLA’ appears to show an unknown type of Chinese submarine in a reservoir
US observer says design looks similar to one reportedly launched in 2018, while Chinese commentator says its smaller hull can increase stealth

A submarine shown in a video posted on social media could be a new, smaller Chinese class prioritising stealth and low cost, and used to counter drones, experts said.

Video footage posted on Facebook in a group called “Comments on the PLA” appeared to show an unknown type of Chinese submarine surfacing in a reservoir.

It appeared to be undergoing early-stage trials, because the footage, posted by a user called Liu Chengliang, showed two white stripes printed on the sail, as is commonly seen on new Chinese submarines during early tests.

The video’s source has yet to be established, but US submarine expert H.I. Sutton said the mystery sub appeared to be not a variant of the Type 039 in service but a smaller single-hull design measuring about 40 to 50 metres (130 to 165 feet).

The Type 039 Yuan-class conventional submarines are double-hulled and about 78 metres long.

Sutton said the footage had also been posted on Twitter, before being removed.

“The design appears related to the sailless submarine,” Sutton wrote on his personal website Covert Shores, comparing the unidentified submarine to another unknown type single-hull sub with a tiny sail that was reportedly launched by Shanghai-based Jiangnan shipyard in 2018.

“The sail is highly blended at the base and has an unusual profile, but it is not unlike some seen on models at Chinese defence shows in the past.”
Aside from their unusual profile designs, the submarine in the video and the one from Jiangnan were of similar size, and were both smaller than China’s most active submarine, the Type 039A, and its upgraded versions, the Type 039B and 039C, according to Sutton.

Beijing-based naval expert Li Jie said that design features such as tiny or embedded sails were aimed at increasing agility and stealth.
“Smaller hulls with similar profiles can enhance the stealth and agility of the vessels,” Li said. “Chinese shipbuilders also need to come up with a variety of new low-cost underwater weapons to deal with low-cost drones.”

Zhou Chenming, a researcher from the Yuan Wang military science and technology institute in Beijing, said the footage was of a model for testing.
“Building a submarine prototype is very expensive, so it’s just a model,” Zhou said.

“All vessel designs and developments need to take hydrodynamic tests. Model testing in reservoirs, not sea waters, is one of the necessary steps in the early stages, which can take at least five years and even a decade.”

US submarine strikes unknown underwater object in disputed South China Sea
China has 56 conventional submarines, with 30 being the Type 039, equipped to enhance their underwater endurance and stealth, according to a Pentagon report to the US Congress last year.

State-owned China Shipbuilding Industry Corporation unveiled some designs of smaller subs at the 2017 Defence and Security Expo in Bangkok. They included a model of a Type MS200 sub, with a length of 30 metres, and the Type S1100, which was 50 metres long.

Minnie Chan is an award-winning journalist, specialising in reporting on defence and diplomacy in China. Her coverage of the US EP-3 spy plane crash with a PLA J-8 in 2001 near the South China Sea opened her door to the military world. Since then, she has had several scoops relating to China's military development. She has been at the Post since 2005 and has a master's in international public affairs from The University of Hong Kong.

Own opinion.

The comparisons with the Swedish A26 may be more apt than expected.

[miletus12]

The Status 6 torpedo is designed to attack San Diego, Norfolk, New York, Newport News, and Pearl Harbor. It is a violation of strategic arms limitation treaties.

[miletus12]

The Russians learned a lot about titanium hulled submarines.

a. Hulls dent and cannot be easily repaired.
b. Deep diving does not provide any defense at all against US torpedoes.
c. They cost a lot to operate.
d. They cannot hold anechoic tiles.
e. They are "noisy".
f. Fire seems to be a huge problem with these types of boats. Merely coincidence that outcome.
g. Small hull diameter restricts sensor and weapon fits.

[stevep]

Mar 3, 2022 2:33:50 GMT miletus12 said:

The Russians learned a lot about titanium hulled submarines.

a. Hulls dent and cannot be easily repaired.
b. Deep diving does not provide any defense at all against US torpedoes.
c. They cost a lot to operate.
d. They cannot hold anechoic tiles.
e. They are "noisy".
f. Fire seems to be a huge problem with these types of boats. Merely coincidence that outcome.
g. Small hull diameter restricts sensor and weapon fits.

  Interesting video although your summary is rather odd in some points:

a. Hulls dent and cannot be easily repaired. - accurate as titanium isn't as ductile as steel.
b. Deep diving does not provide any defense at all against US torpedoes. - I didn't see any reference to that in the video unless your referring to the fact that modern western torpedoes, which came into service some time after the subs, can possibly now catch them?
c. They cost a lot to operate. - The video mentions the much higher construction costs, both because of the greater expense of titanium and the conditions needed for manufacturing i.e. very clean shipyards and argon wielding, plus presumably specialised training.  However I didn't see anything about greater costs to operate.
d. They cannot hold anechoic tiles. - He speculates that they seem to lose acoustic tiles more easily but on what basis I don't know.  He guessed it might be the adhesive being less effective on titanium than steel but whether that's accurate and whether it could be solved or not I don't know?
e. They are "noisy". - He makes the point that the screws are also titanium and the comment that is odd because steel hulled subs don't have steel screws but doesn't say what they are.  True its odd that you would have screws of such expensive material but speculates this could be because of a potential corrosion issue.  He then goes on to say that he doesn't know if its noisier than an ordinary screw and then speculates again that "I don't know for sure that the titanium material makes the sub the propeller noisier, its more likely to deform I guess however hum it definitely seems to complicate things.
f. Fire seems to be a huge problem with these types of boats. Merely coincidence that outcome. - A deep diving small submersible had a fire a couple of years back and one of the fleet subs was lost in 1989, see K-278_Komsomolets which also had a fire but whether that would be a particular problem with titanium hulls, other design features or simple poor quality control in the former USSR its impossible to tell.
g. Small hull diameter restricts sensor and weapon fits. - The video states that the restriction on hull diameter was inherent in the shipyard where the titanium subs were built.  Obviously the greater expense of a titanium hull, see c) above would make using it for construction of a hull scale hull more expensive but I there's no mention of a specific reason that using titanium would technologically restrict the size of the hull.

  It could be that you have other information from elsewhere but the contents of the video differs from your summary in a number of points as noted above.  The video does give arguments that titanium isn't practical for general military subs but largely for reasons you don't mention I believe.

[miletus12]

Mar 4, 2022 14:58:34 GMT stevep said:

Deep diving does not provide any defense at all against US torpedoes. - I didn't see any reference to that in the video unless your referring to the fact that modern western torpedoes, which came into service some time after the subs, can possibly now catch them?

I cannot tell you "why", but the N37s and NT37s were designed to kill the already deep diving Russian boats of the 1950s and 1960s before the titanium subs entered the picture. The floors and speeds of those 19-inch torpedoes were quite sufficient to handle the new Russian subs. It is the British and the French who had to introduce new fish in the 1960s and 1970s. US heavyweights appeared in service in the late 1970s to sink Russian surface ships.

Mar 4, 2022 14:58:34 GMT stevep said:

The video mentions the much higher construction costs, both because of the greater expense of titanium and the conditions needed for manufacturing i.e. very clean shipyards and argon wielding, plus presumably specialised training.  However I didn't see anything about greater costs to operate.

The small crews and specialized reactors equal a very high human training and operations costs. Specialists in an already highly specialized and skills perishable profession is very very expensive.

Mar 4, 2022 14:58:34 GMT stevep said:

He speculates that they seem to lose acoustic tiles more easily but on what basis I don't know.  He guessed it might be the adhesive being less effective on titanium than steel but whether that's accurate and whether it could be solved or not I don't know?

Titanium is slicker than steel hull metal. Marine glue does not adhere well. The Americans ran into this problem with radar absorbing material on their first signal managed aircraft. The "tiles" will not stick in a wet environment.

Mar 4, 2022 14:58:34 GMT stevep said:

A deep diving small submersible had a fire a couple of years back and one of the fleet subs was lost in 1989, see K-278_Komsomolets which also had a fire but whether that would be a particular problem with titanium hulls, other design features or simple poor quality control in the former USSR its impossible to tell.

It is possible to track Soviet and Russian navy accidents and reach some conclusions. They have a dodgy reactor control, coolant circulation, and scram setup by American standards for their light water and pressurized water reactors. Their liquid lead / bismuth cooled primary loop reactors are either paper weights waiting to become cold permanently in a scram or pressure cooker bombs waiting to explode. Their fire-fighting and fire-suppression philosophies are too few men to cover the vulnerable spaces, inadequate training, lousy automatics, and poor engineering choices (A serious material defect also shared in British boats.). The Russians try to go cheap as they can when they build ships and train crews and that bodes ill across their entire navy. You especially cannot go "cheap" in the nuclear fission heat lamp steam turbine propelled navy. And as I noted, the fires, explosions, reactor failures and other engineering incidents have nothing to do with what kind of hull metal is involved. I would argue that a derivative effect of titanium hulled subs, as perceived casually, is that in some cases, their smaller internal volume and much smaller crews than a Russian steel hulled example, plus the use of some liquid metal cooled primary loop fission reactors may have resulted in the false association of titanium hulls with submarine fires.

Mar 4, 2022 14:58:34 GMT stevep said:

He makes the point that the screws are also titanium and the comment that is odd because steel hulled subs don't have steel screws but doesn't say what they are.  True its odd that you would have screws of such expensive material but speculates this could be because of a potential corrosion issue.  He then goes on to say that he doesn't know if its noisier than an ordinary screw and then speculates again that "I don't know for sure that the titanium material makes the sub the propeller noisier, its more likely to deform I guess however hum it definitely seems to complicate things.

Steel subs use bronze screws. The corrosion idea is farcical. Bronze holds up well in seawater. More likely it is a galvanic problem. Titanium is hard to mill after casting, which can result in deformations at the blade tips which results in "popcorning" or bubbling. The noise problem is further based on sound conductivity or what is known as a sound short or "banjo" effect in hull metal. Titanium is not quiet in a flow environment. It hums. Titanium is a lousy sound insulator, too.

[miletus12]

Mar 4, 2022 14:58:34 GMT stevep said:

The video states that the restriction on hull diameter was inherent in the shipyard where the titanium subs were built.  Obviously the greater expense of a titanium hull, see c) above would make using it for construction of a hull scale hull more expensive but I there's no mention of a specific reason that using titanium would technologically restrict the size of the hull.

I had to check back on this one.

It is true that the yard which assembled the hulls for most of the titanium boats had a smaller assembly shed setup. This did not affect hull diameter. One could build fat boats at the yard if one widened the float basin that one put the final pre-commissioned unit into to get it wet. I think the yard simply did not make the adjustment in the launch ramps because it was unnecessary. Now I will speculate why they thought so.

The length to beam ratio and available watts *(Russian submarine fission marine plants usually have more watts than American ones, because the Russians need those added watts to match American performance. Why is rather complex, but it comes down to different outcomes in hydrodynamic  choices and engineering throughput efficiencies in the powertrains.), screw thrust efficiency and desired speeds and depths; which drives barrel diameter more than the wet-down track limit. The Russians wanted fast, and they wanted deep, and they wanted small (Titanium is expensive.) so they built "skinny" for some of their titanium hulled boats for the same reasons Americans do and did for their attack boats . Speed and barrel hoops. Skinny is easier to shove through water than fat. Smaller diameter barrel hoops resist pressure over the arc circle in hull metal better than larger ones.

[stevep]

Mar 4, 2022 16:05:17 GMT miletus12 said:

Mar 4, 2022 14:58:34 GMT stevep said:

The video states that the restriction on hull diameter was inherent in the shipyard where the titanium subs were built.  Obviously the greater expense of a titanium hull, see c) above would make using it for construction of a hull scale hull more expensive but I there's no mention of a specific reason that using titanium would technologically restrict the size of the hull.

I had to check back on this one.

It is true that the yard which assembled the hulls for most of the titanium boats had a smaller assembly shed setup. This did not affect hull diameter. One could build fat boats at the yard if one widened the float basin that one put the final pre-commissioned unit into to get it wet. I think the yard simply did not make the adjustment in the launch ramps because it was unnecessary. Now I will speculate why they thought so.

The length to beam ratio and available watts *(Russian submarine fission marine plants usually have more watts than American ones, because the Russians need those added watts to match American performance. Why is rather complex, but it comes down to different outcomes in hydrodynamic  choices and engineering throughput efficiencies in the powertrains.), screw thrust efficiency and desired speeds and depths; which drives barrel diameter more than the wet-down track limit. The Russians wanted fast, and they wanted deep, and they wanted small (Titanium is expensive.) so they built "skinny" for some of their titanium hulled boats for the same reasons Americans do and did for their attack boats . Speed and barrel hoops. Skinny is easier to shove through water than fat. Smaller diameter barrel hoops resist pressure over the arc circle in hull metal better than larger ones.

miletus12,

  Thanks for clarifying on those points.

  Steve

[miletus12]

USS Bon Homme Richard loss update. (Not going to be popular with some sailors, here. M.)



Summary: the USN continues its historical trend of multiple action tracks when it comes to a major service disaster. It looks for scapegoats, it ducks public responsibility for a service wide deficiency in training and leadership that led to the disaster, it panics and remedially attempts to redress the causes that its own published internal investigation reveals led to the disaster, and in each and every part of the process, shifts the blame, diffuses responsibility and attempts to cover up from or obfuscate to civilian final authority each and every thing it does in the necessary process to correct its organizational deficiencies and mistakes.

It will fix the mistakes. It just does not, like most complacent bureaucracies, to deal with thorny necessary questions like Who allowed, What, Where When, How, and especially WHY, this disaster to happen?    

$2 billion dollar ship burned to the keel and 250 injured sailors, some quite seriously, makes for a big sudden urge to prosecute a LOT of people. The pushback is to find a single scapegoat to save a lot of careers.  

[miletus12]

Type 55. The ship is equivalent to a Flight One Arleigh Burke. That still makes it very dangerous.