It is from @5unrise. It is informed speculation based on what we know about submarine tech and should be regarded as a reasonable guesstimate rather than a fact.
09III/09IV (093/094) Nuclear Submarine Thread
- Thread starter SinoSoldier
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by78
Lieutenant General
This might be of some relevance here.
A procurement document from Huludao shipyard that seeks thermal insulation claddings (made of silicate composites?) for submarine steam turbine and other equipment. The claddings are to be fabricated according to engineering drawings. The total surface area to be covered is around 100 square meters of magnesium-steel alloy weighing some 800kg(?). The winner of the bid will also be responsible for installing the claddings.
A procurement document from Huludao shipyard that seeks thermal insulation claddings (made of silicate composites?) for submarine steam turbine and other equipment. The claddings are to be fabricated according to engineering drawings. The total surface area to be covered is around 100 square meters of magnesium-steel alloy weighing some 800kg(?). The winner of the bid will also be responsible for installing the claddings.
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Slightly off-topic: where is this podcast by Rick Joe and Patchwork located? I would really love to listen to it.
It got taken down by patchwork (was on his YouTube I believe), so basically just have to mostly scour this thread for the general/bigger points they said.
Thanks to @tamsen_ikard's quoting, I had a quick look back to the posts discussing Patch and Rick's podcast from mid-December last year, and I would like to inquire on this:
Because it seems related to what I stumbled upon this photograph, which is posted by @西葛西造舰 just an hour ago:
Notice the top surface of the boat (likely a Virginia SSN).
Is this a normal occurrence on SSNs? Does this also happen to Chinese SSNs? Wouldn't deterioration of the tiles or coatings on this SSN's hull of such a massive degree be seriously detrimental to its stealth capability?
TBH, I'm genuinely shocked by the look of this.
Because it seems related to what I stumbled upon this photograph, which is posted by @西葛西造舰 just an hour ago:
Notice the top surface of the boat (likely a Virginia SSN).
Is this a normal occurrence on SSNs? Does this also happen to Chinese SSNs? Wouldn't deterioration of the tiles or coatings on this SSN's hull of such a massive degree be seriously detrimental to its stealth capability?
TBH, I'm genuinely shocked by the look of this.
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USN's forward deployment is the root cause of this. Forward deployment has some benefits like being able to react more rapidly and diplomatic cookie points with allies. But it is an absurdly expensive practice the US arguably can't sustain anymore with sorry states of its shipbuilding industry and naval procurement. These are just symptoms:
(USCG is getting involved because the navy is getting ruined)
Forward deployment is NOT the root cause of the anechoic tile peeling on Virginia class. Its a changed application from previous tiling used eg on 688/(i) boats and Seawolf, and it has been an issue nearly from "day one". Some boats had this issue already showing up within months when they were still PCU (not commissioned). USN had been working on a fix since at least 2010.
antiterror13
Brigadier
yeahhh, definitely lacking of maintenance
Old anechoic layer was placed as tiles fixed to the hull. New anechoic layer used on Virginia is a continuous mold. This has consequences when hull is deforms during change of pressure.
Every time the sub dives the hull is compressed by water which causes a non-neglible change in size. When it surfaces the hull expands to match atmospheric pressure. While the change of size is not significant the forces that act on the hull and consequently on the anechoic layer fixed to it are tremendous as they are a derivative of the pressure differential. So it is very much like an earthquake on the surface of the hull or a "hull-quake" if you will.
When the hull with tiles is deformed the tiles move independently of each other and often are compressed against each other this - coupled with effect of seawater - causes them to fall off individually after some time. Once an opening in the layer is created more tiles fall off because water puts pressure on the other tiles from their exposed side. But because the tiles are fixed individually to spots on the hull they don't fall off on their own. There needs to be mechanical stress and chemical interaction to get them loose. This is how you get images like this one:
When a hull with molded layer like Virginia deforms the anechoic material doesn't break because it's continuous but it deforms differently from the steel of the hull and begins to peel off from it without breaking its structure. Once that happens then over time due to differences in pressure, temperature, salinity etc the material develops microcracks around the spots where it disconnects from the hull and then water gets inside and it peels off in huge chunks like a blister.
To use biological analogy it's like scales vs skin.
The new technology gives better results on quieting and when done properly stays on the hull longer but when it goes bad it goes bad and is harder and more expensive to replace adding extra time in dock. However I don't think this is the main issue affecting USN submarine readiness and repair time.
From what I've read in official reports the main problem seems to be simply availability of slots due to limited funding. Tools and crews cost money and if USN doesn't pay for them they won't be available on demand. There is also competition for existing funds. Many repairs are done in shipyards other than Groton and Newport and those two already complain about underfunding and inability to increase production rate of Virginias. Columbia has priority so new funding is re-directed there. Boats like USS Boisie which is a 688i commissioned in 1992 simply are not a priority. USS Annapolis from 1992 is slated for retirement in 2027. Boisie isn't probably because all those years in the dock have saved some service life.
Comparing USN's situation to PLAN's is really not constructive because PLAN has active small fleet and expands the infrastructure to match its fleet expansion plans. USN has not enough boats for what its missions are which causes them to be overworked and the infrastructure has been cut to preserve the fleet when budget cuts hit. Still INSURV rates SSNs as highest in condition and readiness while the rest of the fleet fails even more.
Should have been expected anyway. The West wants to choke China to death with an expanding underwater fleet, yet somehow believe that China would not respond in kind? Just give it up.
Although, worthy of note being that Beijing has been planning for the eventual surge in submarine construction for years. On the other hand, AUKUS will serve as a timely booster inside the PLA CMC for demanding even larger budgets to address AUKUS.
Speaking of which, China currently has around ~9 SSNs and ~8 SSBNs in active service (excluding 091 and 092s). The 14th Five-Year Plan (2021-2025) will add another ~9 SSNs and ~2 SSBNs to the PLAN underwater fleet, i.e. ~18 SSNs and ~10 SSBNs in total.
Hopefully China will double the number for the SSBNs and triple the number for the SSNs in the next one or two Five-Year Plan(s) - As part of an (indirect) response package to AUKUS.
Although, worthy of note being that Beijing has been planning for the eventual surge in submarine construction for years. On the other hand, AUKUS will serve as a timely booster inside the PLA CMC for demanding even larger budgets to address AUKUS.
Speaking of which, China currently has around ~9 SSNs and ~8 SSBNs in active service (excluding 091 and 092s). The 14th Five-Year Plan (2021-2025) will add another ~9 SSNs and ~2 SSBNs to the PLAN underwater fleet, i.e. ~18 SSNs and ~10 SSBNs in total.
Hopefully China will double the number for the SSBNs and triple the number for the SSNs in the next one or two Five-Year Plan(s) - As part of an (indirect) response package to AUKUS.
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