PLAN Type 035/039/091/092 Submarine Thread

[jackliu]

Re: PLAN submarines Thread II

If true, this could be powerful indication that china´s nuclear submarine technology is behind the other nuclear powers. They couldnt/cant built anything bigger than type 094.

Did you JUST realize this now? China's nuclear technology is always behind the West. But it does not means they will always be behind in the future.

 

[hkbc]

Re: PLAN submarines Thread II

If true, this could be powerful indication that china´s nuclear submarine technology is behind the other nuclear powers. They couldnt/cant built anything bigger than type 094.

Building a larger pressure hull should be a metallurgical issue rather than a reactor issue, one would expect a larger hull if the problem was with the nuclear reactor since the issue is usually how to build them compact and safe enough. As an SSBN needs to be quiet rather than fast I would have thought losing a couple of knots flank speed by going with a larger, hydro-dynamically cleaner hull, because your reactor is a little under-powered, would be preferable. That is unless the base materials used to fabricate the hull isn't up to it! Maybe they just need smaller missiles and warheads rather than bigger boats!

 

[Kurt]

Re: PLAN submarines Thread II

Building a larger pressure hull should be a metallurgical issue rather than a reactor issue, one would expect a larger hull if the problem was with the nuclear reactor since the issue is usually how to build them compact and safe enough. As an SSBN needs to be quiet rather than fast I would have thought losing a couple of knots flank speed by going with a larger, hydro-dynamically cleaner hull, because your reactor is a little under-powered, would be preferable. That is unless the base materials used to fabricate the hull isn't up to it! Maybe they just need smaller missiles and warheads rather than bigger boats!

With nuclear exposed machinery you have a special phenoma of material fatigue due to neutron capture and subsequent altered isotopes and often atoms with molecular effects. The closer you go to the limits of materials the more this problem will limit safe service times as the neutron radiation exposure is measured in decades with ships being smaller and more susceptible than civilian nuclear reactors due to the smaller size (square law on radiation candela). Military grade material for vehicles with a nuclear reactor is high above requirements for civilian nuclear reactors, although the problems get amplified by downsizing, not by size increase (the French are outstanding in that regard).

No kind of shielding has a significant effect on neutrons and small reactors have increased neutron capture inefficiency, thus radiate more per energy output. Radioactive material in reactors still has neutron emission if it doesn't produce energy, reducing even unused reactor numbers adds material lifetime. This nuclear radiation effect of neutrons does also effect microchips which by dotting atoms receive their specific characteristics. A ship full of electronics with a nuclear reactor on bord is a high-tech machine powered by a luddite. Developing a new design will require extensive efforts for all kinds of materials and especially resistant microchips will be expensive with increasing overall cost and effort effects on nuclear boat designs.
A physicist would either put the microchips or the reactor into the buoy of a warship because radiation decreases with the square of the distance while warship size increases only with the cube root of tonnage. The engineers seem not yet to agree.

The Soviets experimented with mixed nuclear and conventional designs. That might sound unnecessary complicated at first look, but it offers the capability to use only one nuclear reactors that runs very safe at a constant level for cruising. Conventional extra power works as a fail safe substitute for the usual second nuclear reactor and for energy burst requirements. The advantage is having one reactor instead of investing into the usual two. Material fatigue will be diminished if there is much use of non-nuclear energy output that is not nuclear recharged.
After their experiments, the Soviets were not satisfied with the results that were meant as major cost savings due to less nuclear exposition. Today a different verdict might be passed because power output level requirements change with ever more microchips (constant power, very susceptible to nuclear radiation) and electrically powered energy emission sources (intermittent power requirements) on ships that occasionally have to cruise over long distances (a logistic nightmare with major non-nuclear fleet components).

 

[duskylim]

Re: PLAN submarines Thread II

I'm sure they wanted to, but the technologies needed for large diameter hull and a more powerful reactor would be the main limiting factors.

Hmmm.....

I believe that the situation was that they 1st designed the 093 attack sub and then, using the same techniques as the US did with its 1st and 2nd generation boomers simply cut the thing in half and inserted the missile section.

This would suggest that they did not design the 094 as a SSBN from the ground up but rather to save time (and money) they simply drastically modified the 093 hull into one.

That would explain why the missile fairing looks like it does - the 093 hull would be too small to accommodate most of the missile tubes within it's dimensions (especially the height of the tubes) and thus a certain amount of 'kludging' of the fairing was called for, simply to mate the large missile section onto the small, slim SSN hull.

As to the design of large pressure vessels, China's steel industry is the largest and operates the most modern steel plants in the world, and has extensive experience with large pressure vessels (like those used in thermal power plants, hydro-electric plants and nuclear power plants) and the manufacture of the special steels needed for them.

It operates the largest and most powerful forging presses in the world, and has the capacity to forge the pressure vessels' of 1000+ MW class nuclear reactors.

Thus I do not believe that larger hulls or reactors of themselves are/were a problem for them.

What I do believe is that the PLAN is doing what they have done before with the rest of the fleet, that the PLAN submarine force is experimenting with and testing out various designs, (like what happened with the 039 SSK) until they are satisfied that they have one good enough to warrant mass production.

Just my 2 cents.

 

[Kurt]

Re: PLAN submarines Thread II

The microchips are increasingly the critical material on board as limiting diving depth of older vehicles can cope with material fatigue problems.
Military grade nuclear materials are under much more stress than civilian nuclear materials and China has rather built up a factory network for civilian goods than a military-industrial complex of Soviet dimensions with little benefits for the economy.
Military reactors are small, have less nuclear spallation efficiency and a much higher emision of uncaptured neutrons on materials in a very limited space while any civilian system can easily take a few meters more that reduce by factors of thousands!
I have no doubt that China is working on applyable nuclear materials, but you have to recognize that military requirements push far above the envelope of the civilian structure requirements. The question in development can be more complex about directing funds as outstanding nuclear pressure hull materials will be of little value if it's not possible to establish an infrastructure for microchips that can handle this environment. As far as I know, China and Brazil cooperate on nuclear submarines and Brazil and France(among the best in the world in nuclear technology) on dual use underwater nuclear reactors.

 

[kroko]

Re: PLAN submarines Thread II

As far as I know, China and Brazil cooperate on nuclear submarines and Brazil and France(among the best in the world in nuclear technology) on dual use underwater nuclear reactors.

Where did you get this information?

 

[Lion]

Re: PLAN submarines Thread II

Where did you get this information?

There was once a rumour from sina that China passed some know how of submarine nuclear reactor in exchange for Brazil helps in Carrier ops for PLAN.

 

[escobar]

Re: PLAN submarines Thread II

Rescue exercise with a 091G

 

[escobar]

Re: PLAN submarines Thread II

Said to be a psed pic of 091G and 039A subs.

 

[tphuang]

Re: PLAN submarines Thread II

As far as I know, China and Brazil cooperate on nuclear submarines and Brazil and France(among the best in the world in nuclear technology) on dual use underwater nuclear reactors.

I'm fine with you making up stuff in the World forum, but people come here to read about Chinese navy and you gotta stop posting stuff with no evidence here. When you make statements like this, please provide a real (non-wiki) source.

There was once a rumour from sina that China passed some know how of submarine nuclear reactor in exchange for Brazil helps in Carrier ops for PLAN.

Sina rumour was this. What Kurt is saying is he doesn't believe China has enough military nuclear reactor technology and has to get it from cooperating with Brazilians, who gets from cooperating with the French.

There is just no support that is true.