Indian Akula II attack submarine

Originally posted by Schaden
Experts say the new Shang is comparable to a Victor III.

Which experts?

You mean the ONLY reference you made....GlobalSecurity?.

Actually it states
"The new Type 093 Shang-class SSN is thought to be similar in performance to Russian second generation designs such as the Victor III, although it would be incorrect to describe the Chinese submarine as a copy of the Russian Victor III."

And the reason why the Victor III is made as a reference is because it was believed that the Rubin Central Design Bureau was involved with its development. As you can see the second line below, they actually "thought" it might turn out to be a Victor III clone.

I very much doubt that any expert could ascertain a conclusion based on a picture or in Global Securities case, a lack of one. If all reports are correct, the 093 has a HTGR which would, design alone, make it significantly quieter than a LWR

An Akula II in my estimate is without question better than a type 093.Advanced relative to the Han.

Based on?

A) type of propulsion
B) Use of technology
C) Sonar etc


So what technologies makes the Akula II more advanced than the Shang class?

The future of Submarine propulsion



Borei Class. Pump jets are supposed to better disperse bubbles compared to the skewed blades currently used

Originally posted by chinawhite
The future of Submarine propulsion

Borei Class. Pump jets are supposed to better disperse bubbles compared to the skewed blades currently used

LOL LOL LOL...Im sorry Chinawhite....This is very funny...

You do know that for any type of propellor or propulsor...if you are operating correctly ...you are not producing bubbles...correct??..also known as cavitating.

It also means that a skipper/engineer/ crew ..know within what range and changing range/conditions one will produce bubbles or cavitation. How to avoid this if necessary. It also means one knows how to deliberately produce cavitation if necessary.

There is more to a propulsor than what you are describing but what I have posted will have to suffice.

Thanks,
Orangetom

Bubbles = cavitating
?

I didn't describe it in detail but arent Pump jets more efficent than a normal propellor so that it can have a slower revolution but achieve the same speed thus giving it an increased speed overall. Maybe my description of "bubbles" is incorrect?

EDIT: Spelling, unless you want to pit at that aswell







[edit on 4-8-2008 by chinawhite]

Originally posted by chinawhite
The future of Submarine propulsion

Thats funny!!!! You do realise we have been using pumpjets on operational vessels for nearly 30 years!!!!!! The first was HMS Turbulent (ordered 1978 and in service with a pumpjet from 1982)

Thanks for the heads up........

*scratches head*

Maybe in hindsight that picture was not worth posting. I wanted to post a picture of the Borei Pump Jet and needed something to go alone with it. Maybe hit a nerve somewhere?

Originally posted by chinawhite
Its actually quite different in saying they want capability and they have the capability. Your absolutely correct in saying that the Indian military want a SSN I'm saying from all aviable information, they do not have that capability.

Quite. Especially after them having operated a nuclear vessel between 1988 and 1991. As of today IMO, they they do not have any SSN/SSBN operational capability, but my stance was indicative of something else:

"There is no immediate initiative to acquire any nuclear submarine assets (indigenous or otherwise) that would bear operational fruit in the next 5-10 years."

I
Its a ensemble of past Chinese articles so they could range from when the article was published all the way to the 80's.

True, but they wouldn't ensemble it unless they thought that number to still be ambiguous at the time of ensembling I would imagine . baah.. doesn't really matter though.. just very.. quaint.

The Chinese did not claim it as a record and kept it secret so I assume other navies did as well to hide their operational capabilities

They claim it right here IMO:

"Apparently as part of these expanded activities, the current PLAN chief of staff, Sun Jianguo, reportedly commanded Han 403 during a mid-1980s mission of ninety days that broke the eighty-four-day undersea endurance record previously set by USS Nautilus."

Where did you get 10MW?

from here:

The Institute of Nuclear Energy Technology (INET) at Qinghua University has constructed a ten-megawatt HTGR, known as HTR 10.

Not sure what it running on the 093 class; any ideas on the max speed for these boats?

Actually I'm interested in the possiblities or desinated submarines for different missions. The possible design implications that the sentence holds

Oh so you are speculating that Chinese SSNs may have design characteristics that may enable a wider variety of usage options as compared to Soviet/Russian or USN SSNs?

Always plausible.. the HTGR reactor could be one such characteristic..


EDIT: quoting issues..

[edit on 4-8-2008 by Daedalus3]

Originally posted by chinawhite
I didn't describe it in detail but arent Pump jets more efficent than a normal propellor so that it can have a slower revolution but achieve the same speed thus giving it an increased speed overall. Maybe my description of "bubbles" is incorrect?

[edit on 4-8-2008 by chinawhite]

In a sense, bubbles do equal cavitation. Cavitation is the collapse of bubbles that form when hydrostatic pressure drastically decreases at pump or propeller inlets. Bubbles form and then collapse as they reach the elevated pressures at pump discharge. This rapid expansion and collapse acts like tiny explosions, damaging the impeller causing them and making a heck of a lot of noise in the process. Cavitation can let others know where you are and absolutely tear up a pump impeller.

The propulsor shown is designed to prevent blade tip cavitation by increasing hydrostatic pressure at the blade face. They could be considered slightly more efficient because more tangential force is converted to axial force as the water is thrown to the shroud and directed astern. Efficiency is nice, but they're more about quieting. Nearly everything about submarine advances is about quieting.



[edit on 4-8-2008 by oxillini]

remember its not just submarines that suffer from cavitation - remember the BA trip 7 that crashed? there was fuel cavitation within the fuel pump , causing arosion and ultimately failure of the part.


upload.wikimedia.org...

^^ the thing that ALL subs try and avoid

its not just noise which would be an issue - permanant damage can occur:

upload.wikimedia.org...

yes that was caused by those pesky ` bubbles`


i musy say , that is a nice picture of the pump-jet , you don`t get to see them that often as they are usually covered as being a closely guarded secret.

good find

reply to post by orangetom1999


As to your question about how a reactor is run to change to max speed...I will not comment on how this is done nor go into this arena in the intrest of security


they decrease the amount of containment rods to increase the reaction process - standard procedure on nuclear reactors - unless the US has somehow managed to not use graphite rods for control - which would be a first on teh entire planet really (because how else would you control the neutron emissions in the event of a scram)

Originally posted by Harlequin
reply to post by orangetom1999

 

As to your question about how a reactor is run to change to max speed...I will not comment on how this is done nor go into this arena in the intrest of security


they decrease the amount of containment rods to increase the reaction process - standard procedure on nuclear reactors - unless the US has somehow managed to not use graphite rods for control - which would be a first on teh entire planet really (because how else would you control the neutron emissions in the event of a scram)

The US Navy does not use graphite control rods. This is publicly available information. Hafnium is used for a host of reasons. Also, they're control rods, not containment rods, that's mixing two separate terminologies.

reply to post by oxillini


my humble apologise - tis been a long night with the baby who is teething;

Hafoloy-M (also -N and -NM) is whats used - still control rods though

Originally posted by chinawhite
You mean the ONLY reference you made....GlobalSecurity?.

Actually it states
"The new Type 093 Shang-class SSN is thought to be similar in performance to Russian second generation designs such as the Victor III, although it would be incorrect to describe the Chinese submarine as a copy of the Russian Victor III."

And the reason why the Victor III is made as a reference is because it was believed that the Rubin Central Design Bureau was involved with its development. As you can see the second line below, they actually "thought" it might turn out to be a Victor III clone.

You seem to be implying the Victor III analogy is inaccurate because it wasn't a clone. That wasn't the sole basis of analysis!

Again, I never said it was a clone. I clearly stated it had comparable performance to a Victor III. You're the one who erringly posted copy=comparable. Rubin Central Design was involved, to what extent nobody knows, but it was still primarily designed and constructed within China.

You want another source ? How about sinodefense.com ?

They say:

The Type 093 is thought to be approaching the early variants of the U.S. Navy 688 (Los Angeles) class SSN in terms of capability and noise level, but still inferior to the more advanced Seawolf and Virginia class.

www.sinodefence.com...

Approaching flight one 688s. So the brand new Shang class is not yet at the level of 30+ year old American submarine technology.

Originally posted by chinawhite
I very much doubt that any expert could ascertain a conclusion based on a picture or in Global Securities case, a lack of one. If all reports are correct, the 093 has a HTGR which would, design alone, make it significantly quieter than a LWR

Read up. The experts aren't making these estimates on its capabilities solely off a picture on a website. It is incorrect to say, by design alone, an HTGR submarine is significantly quieter than a PWR submarine. There are so many factors involved besides the configuration of the reactor. Don't ask me details, most of it is classified, and above my level of knowledge anyways. I was only a crew member, I didn't design the damn things.

originally posted by Schaden
An Akula II in my estimate is without question better than a type 093. Advanced relative to the Han.

Based on?

Common sense ? If experts believe the type 093 is still behind an early Los Angeles class, and that a Shang class sub is comparable to a Victor III, how could an Akula II (a sub that by most accounts is better than an early LA) NOT be more advanced ?

Originally posted by Daedalus3
"There is no immediate initiative to acquire any nuclear submarine assets (indigenous or otherwise) that would bear operational fruit in the next 5-10 years."

I certainly agree with that. The ATV afterall has been in the works for quite some time. What I am contesting is whether the Akula II is being sold/leased to India in the near future or further on from what I have read.

They claim it right here IMO:

The newer submarines after all were supposedly lengthened by 8m. This is according to Janes. I belive the older Han submarines were the ones which gave the class a bad name, rightly or wrongly but the newer Han class which have been under numerous refits have better capability something similar to the J-8 and J-8II

Not sure what it running on the 093 class; any ideas on the max speed for these boats?

The HTR-10 is just a technology demonstator. A larger version has already been given the green light to begin development. Anyway in the field of HTGR or VHTR China is one of the world leaders since most major nations either gave up or have put these on the backburner

Originally posted by Schaden
You seem to be implying the Victor III analogy is inaccurate because it wasn't a clone. That wasn't the sole basis of analysis!

No, I am not suggesting that. I'm saying that the Victor III is only used as a comparison by GlobalSecurity because they intially thought that the design of the 093 was going to be based on the design of the Victor III and hence their comparison with it. The statement GS made is outdated and hence not a reliable source of information.

Obviously the line below is incorrect because from the pictures now obtained and previously unaviable to GS indicates that it has NOTHING in common with the Victor III.
"although it would be incorrect to describe the Chinese submarine as a copy of the Russian Victor III"

eg. If they had pictures showing a LA look-alike they quite possibly would say comparable to the LA class. They thought it would be heavily influenced by Rubins which designed the Victoria III so they suggested it was going to be heavily influenced by them.

I am not suggesting your saying it is a clone. I associated that term with GS and did not point you out and say that

How about sinodefense.com ?

Sinodefence is a site created by a Chinese military hobbyist residing in the UK. If you knew him or have been around Chinese military forums you would have known that. BTW you can get into contact with him at their forum, he goes by the name DongFeng

It is incorrect to say, by design alone, an HTGR submarine is significantly quieter than a PWR submarine.

HTGR minus the pumping systems is significantly quieter than a LWR. All things being equal the HTGR will produce less movement. Just look at a pebble bed reactor and tell me what you think.

If experts believe the type 093 is still behind an early Los Angeles class,

I repeat. Sinodefence is NOT a expert site for the reasons I highlighted above. To claim that it has creditbility in regards to capabilities of military capability is absurd. At most it can be used as a reference for "current" military equipment which has been previously studied.

You may question my sources all day long, but everything I've read on the web says the same thing. And yeah ONI are experts who are some of the sources these articles get their info from. It's not amateurs making up these estimates.



Enjoy the Olympics. Type 093 wouldn't stand a chance against a modern western SSN. It would be detected and sunk before it knew what happened.





[edit on 5-8-2008 by Schaden]

China have built all of 2 classes and 5 (maybe 6) SSN`s - and your saying there first effort was as good as a 688 :O

you say that the seawolf and virginia ae better - thats very true , but since there all of 3 seawolf and 5 virginia - its not that many.

remember the USA was building SSN`s in teh 1950`s starting with the Skate class , so this must be looked at when comparing theses boats

Originally posted by Schaden

Thank you for conviently leaving out the source.

How Quiet Is It?

I see a lot of comparisons thrown around about how quiet Chin’s 093 and 094 submarines are, with comparisons to the Victor III and Los Angeles-class (USN 688) submarines.

Data for that is hard to come by, but in 1997, the Office of Naval Intelligence released a chart comparing the performance of China’s new nuclear powered attack submarine (SSN), the 093, on which the 094 is said to share a design heritage.

Obviously, ONI didn’t release any numbers. But thanks to Tom Stefanick’s classic Strategic Antisubmarine Warfare and Naval Strategy, we can place China’s SSBN between 130-150 decibels (with a lot of specific qualifications outlined on pp272-279).

ONI’s estimate was done before we actually saw the submarine, however. An interesting comparison would be to compare the volume of the 093 to the Victor III. Modern quieting involves sound isolating mounts; Stefanick observes a relationship between quieting and larger submarines.

Armcontrolwork.com


A chart published in 1997 when the submarine wasn't yet seen.


How much more of a reliable source can we hope to get

You may question my sources all day long, but everything I've read on the web says the same thing.

Coming from the same person who claimed a military enthusiast website as having expertise on the subject....All you have read are inaccurate assumptions published by a site who rarely updates their information.

Type 093 wouldn't stand a chance against a modern western SSN. It would be detected and sunk before it knew what happened.

Very mature for a supposed navy man.

Considering the recent showings of submarines against the US, I very much doubt your statement like your own "estimate" based on "expert" opinion to hold any weight

Harlequin,

I wanted to thank you for the photo of the propellor under cavitation...great photo.

As to the other one of an impeller from a pump. I am not so sure that one is damaged from cavitation as much as it looks like it ingested something very hard. Either way of course is not good for the impeller in the long run.

Years ago there used to be two ships which would return here to the Newport News Yard for repairs. They were Amazon Dredge Boats. Huge pumps/impellers on them with a very large boom and on this boom a pipe for the discharge from these pumps. When you crawled into these pumps the impellers were very dinged up from sucking so much debris off the bottom of the riverbed. I remember them because they were such a dirty messy and unkept type of ship. Of course the Amazon is a fast moving river in places so it would be a full time job to keep it in navigatable condition in cetain areas. Nonetheless ..they were some rough dinged up impellers like the one in the photo,

Thanks for the photos.

ChinaWhite,

HTGR minus the pumping systems is significantly quieter than a LWR. All things being equal the HTGR will produce less movement. Just look at a pebble bed reactor and tell me what you think.

You need to think about this. All is not as it seems here even with LWR's and the manner in which they are used at sea.

Must make haste today...catch up with the board later.

Orangetom