Indian Naval Discussion

NRao · Post by **NRao** » 27 Jun 2009 23:37

Outside of livefist, is there anyone reporting this V-22 stuff?

Even livefist claimed an early appearance, so far nothing.

Katare · Post by **Katare** » 28 Jun 2009 00:05

Osprey is a revolutionary xover design so it is bound to have a lot of problems in early development/deployment phase. When problems are fixed in Mk2, 3 avatar, it'll provide opportunities for missions that no other aircrafts can. Although at this moment it appears a very risky and immature product.

NRao · Post by **NRao** » 28 Jun 2009 02:34

They have deployed the V-22 in both Iraq and Afghanistan. I tried to google and find any stats but could not find anything useful to this discussion.

With that in mind, how worthless can it be.

Also keep in mind that the US uses it for a ton of things, IN is THINKING of it only in one role (granted so far).

NRao · Post by **NRao** » 28 Jun 2009 02:39

OK, found one article:

June 23, 2009 :: GAO pans V-22 Osprey's Iraq tour; now it's off to Afghanistan

The aircraft also continues to struggle with reliability issues that made its mission capability far below expectations during three tours in Iraq and left Marines cannibalizing other Ospreys for spare parts, despite a price tag that's climbed to $121 million apiece.

Heavy in price too!

The Government Accountability Office, a nonpartisan congressional agency that audits federal programs, reviewed the aircraft's Iraq mission reports, interviewed pilots and concluded last month that the Marines ought to revisit the Osprey and look for alternatives.

That should do it I would hope.

Drevin · Post by **Drevin** » 28 Jun 2009 09:16

I know that, what about our NLCA?
what about ASW helicopters?

How many helos have ifr today ? The only one I can recall is the latest version of the chinook.
Why can't NLCA do buddy-buddy ? It will get a IFR probe.

mv22aew has lots of problems vishnu ..... those huge propellers, the added weight of a triangular disc. Its not even a reality. The whole mv22aew is just a paper concept like mca as of now. Immediate solution would be a mkized eh101 .... but we already are committed to ka31.

Also plz correct me gurus, I thought a ship-based aew's priority is early warning activities near the carrier. Basically protect the battle group. Not coordinate an independant strike mission far away from the battle group. Ka31 is pretty decent for that.

Drevin · Post by **Drevin** » 28 Jun 2009 10:33

<ot>

http://jcbot.com/news/333

In link above check out the proposed helo ka90 ...... cruise speed 378kts = 700kmph

Also the flying sirkosky x2 is compared with the ka90/92. X2 is to reach 250kts by the end of 2009.

</ot>

I'd rather that the IN shows interest in these programs than the v22. ka31 is good enough for now. vishnu i hope you are convinced now that future helos can reach speeds of 800kmph

There is no need for the v22. It may get dropped soon.

jmt

SKrishna · Post by **SKrishna** » 28 Jun 2009 12:33

For ship borne AEW, the limiting factor is the operating ceiling, for higher the aircraft goes, longer is its detection range (figuratively speaking but of course limited by the detection range of the radar). Heli borne AEWs are handicapped as helicopter cant go as high as aircraft. Even the Osprey dont go too high. But with a pressurized cabin it can possibly do and thus make a good option (if reliability issues get sorted out)

Drevin · Post by **Drevin** » 28 Jun 2009 12:40

Just because you can go higher doesn't mean you can see an area with radius of 1000kms. The limit is the capacity of the radar. There is a "law of diminishing returns".

I dont see any future whatsoever for the v22. US Marines poured billions of useless funds into this project. We should stay away from this product.

And the role it was supposed to be used for in the US Marines will be supported by helos by 2015. Far cheaper, far more reliable.

jmt

vavinash · Post by **vavinash** » 28 Jun 2009 14:15

vishnu, thanks for the link but still can the AEW version be folded? More importantly on't the out-sized rotors on the V-22 affect the performance of the radars.

SKrishna · Post by **SKrishna** » 28 Jun 2009 15:38

vavinash wrote:vishnu, thanks for the link but still can the AEW version be folded? More importantly on't the out-sized rotors on the V-22 affect the performance of the radars.

Folded config of V-22 FOAEW

Yes it can be folded see link

See other info on V-22 FOAEW for RN

Tilak · Post by **Tilak** » 28 Jun 2009 22:37

SKrishna wrote:
vavinash wrote:vishnu, thanks for the link but still can the AEW version be folded? More importantly on't the out-sized rotors on the V-22 affect the performance of the radars.
Folded config of V-22 FOAEW

Yes it can be folded see link

See other info on V-22 FOAEW for RN

Since the info being posted here is hopelessly out of date and bordering on fanboyism

.. may be this will end V-22 speculation@Shiv Aroor , if I remember correctly Cheney(Bush Administration) also wanted to kill the Osprey.

Pentagon ‘Stonewall’ on Osprey
By Colin Clark Thursday, May 21st, 2009 12:01 pm

Congressman: Stop Building Ospreys
* By Noah Shachtman Email Author
* June 23, 2009 |
* 5:03 pm

A powerful Congressman has called on the Marines to stop production on their controversial tiltrotor craft, the V-22 Osprey.

The Marine Corps’ leadership say they’re thrilled with how the Osprey has performed in Iraq — the aircraft’s first deployment, after nearly three decades in development. But critics say the aircraft still has a whole host of performance and safety issues; only about half of the fleet of 90 Ospreys are actually combat deployable. The cost per flight hour is over $11,000 — more than double the target estimate, according to a new Government Accountability Office report, presented at a hearing of the House Oversight and Government Reform Committee. Overall, the program has cost over $25 billion in research , development, production, and maintenance.

“Not only has the Osprey failed to live up to its initial billing, it has failed expensively,” declared committee chairman Ed Towns. “It’s time to put the Osprey out of its misery.”

Obviously, the Marine Corps disagree. And it’s not immediately clear what, if anything, Rep. Towns can do to stop the Marines They’re already halfway through production. The assembly line is efficient. Prices (while high) are stable. And they are working to fix some of the most egregious problems with the aircraft.

The DEW Line and POGO both live-Tweeted the often-fiery, often-hilarious hearing on the Osprey. Both are must-reads. But the DEW Line’s final update is particularly great. “V-22 hearing ends. USMC colonel says into live mike: ‘This has been a waste of time.’ Gen Trautman says quickly: ‘Calm down!’”

Hot-Breathing Osprey Sparks Five-Acre Fire

An unfortunate incident last month when a MV-22 Osprey was damaged in a grass fire is just the latest indication that the tilt-rotor’s fearsomely hot exhaust can cause real problems; it can even damage ships’ decks.

Eagle-eyed Osprey-watcher Springbored noticed some differences between the Marine Corps explanation of the event and the coverage on a local news channel in North Carolina, where the incident occurred.

In the official version, the aircraft landed due to mechanical problems at 7 pm in Holly Shelter Game Land in Pender County, NC. When it was preparing to take off, the heat from the exhaust ignited the grass underneath it.

“The grass fire was quickly extinguished by the crew chief, but caused an undetermined amount of heat damage to the aircraft exterior,” according to a rather bland Corps statement.

The News 14 version is more colorful. They say that fire-fighters did not bring the blaze under control until 11 pm, implying a larger conflagration that could not be put out by one man with a portable extinguisher. Springbored quotes another local news source saying that brush was set on fire. Local emergency management director Eddie King added, “It burned a little less than five acres.”

Springbored can claim some foresight on this one. In April, he stated, “we’ve known for years that V-22 downwash is notorious for setting nearby vegetation afire” and questioned how this would affect training exercises in Southern California during the dry season” “Are MV-22s going to be restricted to landing at only neatly-groomed, nicely leveled backwoods landing sites? Or do Marines just like hopping off their transport with fire extinguishers?” (Cue the joke about arriving in a hot Landing Zone.)

A few fires are one thing, but the hot exhaust can also cause trouble on board a ship, where it can warp steel. Last month Aviation Week reported that as well as reliability issues, the exhaust was a problem:

It was discovered that on smaller deck amphibious ships, heat from the downward-pointing nacelles could potentially warp the stringers [horizontal structural beams] underneath the deck plates. “We’re concerned with heat on the LPD and LSD decks because the steel is so thin,” Trautman said, adding that the service has “worked through that challenge.”

There are two suggested solutions. One is to angle the nacelles forward rather than leaving them vertical, which would allow the aircraft to remain for about half an hour. The alternative is to add deck plates which would give ninety minutes of protection.

Secrecy and a refusal to disclose details of the aircraft’s operational rate in Iraq (rumored to be poor) have increased the rumblings of doom; a Marine general has suggested buying less Ospreys and more helicopters. At least the Osprey involved in last month’s incident avoided serious damage: explaining how your $73 million aircraft came to be destroyed by a forest fire it had started would be really embarrassing.

Interesting Info :
Why Tilt Rotors Fail

Tiltrotors fail because they are only half as efficient as a helicopter and also half as efficient as an airplane. Therefore, they do not have the payload or range of either a helicopter or an airplane. The ability to take off and land vertically, however, and to carry at least some small payload faster than a helicopter, is their niche role. One reason tiltrotors fail is because the "proprotors" are an engineering design compromise between a helicopter's large diameter relatively untwisted flat blades, and a propeller's smaller and much more twisted blades. Large diameter blades provide better efficiency, which is why they are used by helicopters. But much smaller diameter blades are required to pull an airplane efficiently through the air. As the V-22 builds up speed, its massive proprotors create more drag and become less efficient, and eventually fuel efficiency and range suffers. The size of the V-22's wing is also a compromise, in that because of its short span and high wing thickness it creates much more drag than for an airplane.

Compare the V-22 (right) with the new C-27J Spartan military transport (below), not be confused with the much older C-27A once used by the USAF. This aircraft uses the same two engines as the V-22 and is roughly the same size, measured in empty weight. Yet the Spartan can carry twice the payload of the V-22 three times farther. Its larger cabin can carry a Hummer or several more troops than a V-22.

Most of this is because the Spartan has small twisted propellers, but also because the V-22 has short wings to save weight and fit aboard ship. A tiltrotor can fly like an airplane, but with less than half its performance in payload and range. Cruise speed is lower as well, around 220 knots for the V-22 vs. 305 knots for the Spartan.
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Austin · Post by **Austin** » 29 Jun 2009 09:59

Bharat Karnad in his book "India's Nuclear Policy" mentions that ATV will be a double hull submarine made from Titanium.

Perhaps he means Titanium alloys , but if it is indeed made from Titanium Alloys atleast the pressure hull , then it would be a great achievement , so far only Soviet/Russia has demonstrated the capability to built the entire submarine from Titanium alloys.

But its a difficult task to achieve as they need special environment with some gas filled ( i dont remember which was it ) to weld Titanium metals else it tends to crack and need skilled workers.

So have we achieved this kind of capability ?

The advantage is depth afforded by such material , this should do a comfortable 600 m and need be go down below 1 Km as demonstrated by Alfa.

Singha · Post by **Singha** » 29 Jun 2009 10:55

I dont think ATV will be titanium. even USSR gave up on its Sierra class (sister of steel hulled Akula) due to cost reasons and I think they have all the titanium needed incountry.

more than raw depth which a torpedo can comfortable follow on you, its
quietness, passive sensors, good torpedo, tube launched ASM, integrated combat system and high 'silent speed' that matters imho. the Virginia class
sure has some soothing star trek C3I stuff per a few pix I saw somewhere.

most of our future naval incidents would be in the belt of 'green water'
the Andaman sea, molucca, sunda strait, lombok straits, new guinea,
banda aceh, sarawak-borneo, java, sumatra, bali, timor sea, south china sea

this is also the most beautiful area of sea and islands in
the world....quite a pity the nasty dragon wants to have it.

a relatively small 6500t quiet littoral warfare SSN with high transit speed to
surge out of Rambilly and reach patrol location is what we need and what the ATV will perhaps be. they will certainly work in wolfpacks with AIP
equipped SSKs from the mainland and advance based carved outa some
cliff / harbour in A & N islands (perhaps greater andaman for easier logistics)..supported by a naval air station with LRMP.

any future IN SSBN would avoid this green water and instead head for the
ultra deep and untrafficed water of the central and southern indian ocean
upto antarctica. except for a shipping route from australia to cape of good hope, this is one 'dead zone' and very deep as befits the strategic role
of a SSBN to hide and wait. PLAN will find it tough to track anything that far south and so far from land unless they obtain a full fledged submarine base in mauritius or madagascar - we must stop that at all costs

Rahul M · Post by **Rahul M** » 29 Jun 2009 10:59

agree with singha, unlikely we will attempt at gold-plating our very first attempt. also consider that IN's budget is nowhere near what red navy could have afforded back in those days and they had to let go of dream for cost reasons !

Nirmal · Post by **Nirmal** » 29 Jun 2009 15:06

Austin wrote:Bharat Karnad in his book "India's Nuclear Policy" mentions that ATV will be a double hull submarine made from Titanium.

Perhaps he means Titanium alloys , but if it is indeed made from Titanium Alloys atleast the pressure hull , then it would be a great achievement , so far only Soviet/Russia has demonstrated the capability to built the entire submarine from Titanium alloys.

But its a difficult task to achieve as they need special environment with some gas filled ( i dont remember which was it ) to weld Titanium metals else it tends to crack and need skilled workers.

So have we achieved this kind of capability ?

The advantage is depth afforded by such material , this should do a comfortable 600 m and need be go down below 1 Km as demonstrated by Alfa.

A tiffin wallah known to my Uncle can confirm ATV is double hull design as also announced by L&T who built it at Hazira and then towed it Vizag for integration. Use of Titanium based alloys was initally toyed with but was given up in favour of special steel alloy from Russia which is now manufactured by SAIL HY100 or HY90.

sum · Post by **sum** » 29 Jun 2009 16:13

Thanks for the info, Nirmal-ji...

Is there another ATV also being built as i type?

Igorr · Post by **Igorr** » 29 Jun 2009 16:30

New vids about Russian naval stuff from IMDS-2009 Naval Show in San-Petersburg, June, 27, 2009.

Pr.20382 "Steregushchiy' class stealth corvette
http://www.youtube.com/watch?v=d7Vbrn0M6po
http://www.youtube.com/watch?v=lx3NUz93V-k

Paket-E/NK mini-antitorpedo
http://www.youtube.com/watch?v=KBpNNVuD4ik

Also Indo-Russian 'Brahmos' tests video (not completely new)
http://www.youtube.com/watch?v=xB6R3NsD-yQ

Austin · Post by **Austin** » 29 Jun 2009 17:19

For its displacement of ~ 2000 T the Steregushchiy is a well armed and sensored ship , wonder if its Top Heavy or any way this will affect its sea keeping qualities.

The interesting part is the target which is F-18 and Virginia , cold war legacy...

Hopefully our P-28 with ~ 2,500 T will be equally capable corvette.

The Brahmos ripping apart and sinking the IN corvette in a matter of few minutes its eye candy

John · Post by **John** » 29 Jun 2009 19:43

Pr.20382 class can also be fitted with VLS SAM system (using SA-15) and 8 Yakhont (in place of Kashtan). I believer later builds were supposed to have that fit. Orginally plan was russian navy will procure a fleet of corvette to maintain its fleet levels but the plan feel apart. Due to stability issues and costs saving was minimal. Plan now is to build new class of Frigates to replace the aging Sovernmennys and Udaloys eventually.

I do wish they incoporate Steregushchiy's mast design and main gun encasing on to the second batch of Talwar.

vavinash · Post by **vavinash** » 29 Jun 2009 22:15

The P-28 doesn't even carry any AShM's if I remember correctly. No point comparing Steregushchiy with P-28's. The P-28 was supposed to join IN around 2009-2010. Haven't heard a word from GRSE in a while.

Nirmal · Post by **Nirmal** » 30 Jun 2009 00:49

sum wrote:Thanks for the info, Nirmal-ji...

Is there another ATV also being built as i type?

According to a chaiwallah outside L&T who spoke to my second cousin, the Hull for the second ATV is already under construction. Further details on the second ATV bit difficult to come by at present. It will be a bigger in size and tonnage than the first.

Philip · Post by **Philip** » 30 Jun 2009 04:27

.."vessels of another class".Key words.Perhaps referring to the Russo-Italian AIP sub design?

http://en.rian.ru/russia/20090626/155359644.html

Russia Russia to take part in Indian diesel submarine tender
RIA Novosti Vitaliy Ankov | Buy this imageRelated NewsRussia may export up to 40 diesel submarines by 2015
Divers discover wreckage of Soviet WWII submarine in Baltic Sea
Russia's submarine fleet has 60 vessels in active service
Russia's Yury Dolgoruky submarine to start sea trials by yearend

13:4126/06/2009
MultimediaPhoto:The 4th International Maritime Defense Show in St. Petersburg
Photo:Russian naval task force completes exercise in the Atlantic
Video:Nuclear submarine accident caused by fire-safety system
ST. PETERSBURG, June 26 (RIA Novosti) - Russia will participate in an expected tender to supply diesel-electric submarines to the Indian navy, the Russian state arms exporter said on Friday.

"We will offer India an export version of the Lada class diesel submarine - the Amur class vessel. We will take part in the Indian tender when it is announced with these submarines or vessels of another class," said Oleg Azizov, head of Rosoboronexport's delegation at the International Maritime Defense Show 2009 in St. Petersburg.

"We have a bilateral cooperation agreement [in the military-technical sphere] until 2020, which includes the possibility of supplying submarines to this country," Azizov added.

The Project-677, or Lada class, diesel submarine, whose export version is known as the Amur 1650, features a new anti-sonar coating for its hull, an extended cruising range, and advanced anti-ship and anti-submarine weaponry, including the Club-S integrated cruise missile systems.

Azizov also said Vietnam and Egypt were studying the possibility of buying Russian Project 636 Kilo class diesel submarines.

"Vietnam is still studying various possibilities for the development of its submarine fleet. If they choose Project 636 submarines, offered by Russia, we will start talks on the issue," the official said, adding that the same approach applied to Egypt.

The Project 636 Kilo class submarine is thought to be one of the most silent submarine classes in the world. It has been specifically designed for anti-shipping and anti-submarine operations in relatively shallow waters.

Russia has built Kilo class submarines for India, China and Iran.

Azizov earlier said Russia could sell up to 40 fourth-generation diesel-electric submarines to foreign customers by 2015.

Philip · Post by **Philip** » 30 Jun 2009 04:30

Titanium hulled subs are terribly expensive and difficult to build.The Alfa class,reportedly the fastest subs ever,were never replicated by the Russians.

Gagan · Post by **Gagan** » 30 Jun 2009 07:05

The russians did have a follow on to the titanium hulled Alfa Class subs.
These were the four Sierra class subs. These featured a double titanium hull.
Last I heard, three were in service, one was retired.
The Sierra was the precursor to the Akula class subs, the hull of the sierra resembles the akula hull, except for the smaller conning tower on the Sierra.

chetak · Post by **chetak** » 30 Jun 2009 09:20

Philip wrote:Titanium hulled subs are terribly expensive and difficult to build.The Alfa class,reportedly the fastest subs ever,were never replicated by the Russians.

Philip sir,

The Alfa class was discontinued because problems with the reactor ( the problem is that the lead/bismuth coolant used in the reactor solidifies at 125 degrees C.) and not because of the cost of the titanium or with problems with the matériel. The Russians are the world leaders by far for titanium technology. No body else even comes close.

Quote wiki

The OK-550 plant was used on Project 705, but later, on 705K, the BM-40A plant was installed due to the low reliability of the OK-550. While more reliable, BM-40A still turned out to be much more demanding in maintenance than older pressurized water reactors. The issue is that the lead/bismuth eutectic solution solidifies at 125 degrees C. If it ever hardened it would be impossible to restart the reactor, since the fuel assemblies would be frozen in the solidified coolant, so whenever the reactor is shut down it must be heated externally with superheated steam. Near the piers where the submarines were moored, a special facility was constructed to deliver superheated steam to the vessels' reactors when the reactors were shut down. A smaller ship was also stationed at the pier to deliver steam from its steam plant to the Alfa submarines.

Coastal facilities were treated with much less attention than the submarines and often turned out unable to heat the submarines reactors. Consequently the plants had to be kept running even while the subs were in harbour. The facilities completely broke down early in the 1980s and since then the reactors of all operational Alfa submarines were kept constantly running. While the BM-40A reactors are able to work for many years without stopping, they were not specifically designed for such treatment and any serious reactor maintenance became impossible. This led to a number of failures, including coolant leaks and one reactor broken down and frozen while at sea. However, constantly running the reactors proved better than relying on the coastal facilities. Four vessels were decommissioned due to freezing of the coolant.

Both the OK-550 and the BM-40A designs were single-use reactors and could not be refuelled as the coolant would inevitably freeze in the process. This was compensated for by a much longer lifetime on their only load (up to 15 years), after which the reactors would be completely replaced. While such a solution could potentially decrease service times and increase reliability, it is still more expensive, and the idea of single-use reactors was unpopular in the 1970s. Furthermore, Project 705 does not have a modular design that would allow quick replacement of reactors, so such maintenance would take at least as long as refueling a normal submarine.

Austin · Post by **Austin** » 30 Jun 2009 09:45

The IN Frigate INS Beas and the Russi corvette Steregushchy held their first joint exercise in Gulf of Finland , video of the exercise

Project 20380 corvette “Steregushchy” completes exercise with Indian navy

prashanth · Post by **prashanth** » 30 Jun 2009 13:25

About ATV, I think 15m beam width( estimated) is too wide for a single hulled ship of 6500 tonnes. (when compared with other single hulled subs. Source wiki.)

Austin · Post by **Austin** » 30 Jun 2009 15:44

Nirmal wrote:A tiffin wallah known to my Uncle can confirm ATV is double hull design as also announced by L&T who built it at Hazira and then towed it Vizag for integration. Use of Titanium based alloys was initally toyed with but was given up in favour of special steel alloy from Russia which is now manufactured by SAIL HY100 or HY90.

Double hull should afford more reserve buoyancy , additional protection and four way silencing with a more hydrodynamical efficient outer hull design.

Rahul M · Post by **Rahul M** » 30 Jun 2009 15:57

I can understand the need for double hull designs for operating in the artic (punching through ice cap and so forth), but is it a good choice for a sub meant to operate in the tropics ?
double hulled --> inefficient use of space.

kit · Post by **kit** » 30 Jun 2009 16:15

Rahul M wrote:I can understand the need for double hull designs for operating in the artic (punching through ice cap and so forth), but is it a good choice for a sub meant to operate in the tropics ?
double hulled --> inefficient use of space.

Probably.But more safe especially for SSBN s and more.. when u have more expertise and are comfortable with your submarine technology and materials, you can go for single hulled next gen subs .. just my thought .. indians like to play it safe.

vina · Post by **vina** » 30 Jun 2009 16:22

Double hull should afford more reserve buoyancy , additional protection and four way silencing with a more hydrodynamical efficient outer hull design.

Not true. The spaces between the two hulls are free flooding. The inner hull is the pressure hull. The outer hull is just a plain sheet of metal , with equal water pressure on both sides of the plate. Yeah, you can build the boyancy tanks OUTSIDE the inner hull in double hull submarine without compromising hydrodynamics and can build bigger ones with larger reserve buoyancy than you would do in a single hull

double hulled --> inefficient use of space.

Not true. See above comment. Theortecially you can have the entire inner hull dedicated to machinery and living spaces with the boyuancy tanks in the space between the hulls.

Problem is the double hull boat will have higher light ship weight , ie wt of steel / displacement . So it is structurally less efficient for a given displacement than a single hull design. and not to mention more expensive as well with much more welding (theoretically twice). Tonnage (volume wise) it is quite efficient. However since steel weight is more, you have less allowance for machinery , weapons, fuel etc. So for a given requirement (payload, range etc) a double hulled boat will be bigger , have more displacement and rather more expensive than a single hull desingn.

It is the old sterotype. BRute force, cost no objective --> russia , "efficienct" designs --> west

Philip · Post by **Philip** » 01 Jul 2009 03:59

The Kilos we have have double hulls and these hulls have the advantage of being able to have quieting methods applied to both the inner and outer hulls.In addition,a lot of machinery can be located between the two,including missile silos.The extra safety /battle damage capability is superior to single hulled subs.Pics of Russian subs damaged during Cold war accidents,show how tough the double hulls are.

vina · Post by **vina** » 01 Jul 2009 07:40

How do they clean the fouling in a double hull sub I wonder. That must be a huge maintenance b**ch. Anyone who has seen a ship in a dry dock after it has spent just 6 months or so at sea will immediately know the problem. Single hull it is easy to just scrub it off. Double hull, just scraping the huge surface area of all both the hulls will be atleast thrice the work of a single hull.

atma · Post by **atma** » 01 Jul 2009 08:21

I thought most modern submarines whether western or Russi, were inherently double hulled. With an outer 'light hull' to provide the hydrodynamic effect, and one or several inner 'pressure hulls' Am I missing something? I guess the Russi designs called for a double hull through out rather than in some sections of the craft. I hope our designers are seeking the best to design our ATV.

Anujan · Post by **Anujan** » 01 Jul 2009 08:50

There is this huge double-hull single-hull debate with each side doing psy-ops on the other. Not clear which is better.

Russies went for double hulled design. Said that the inner hull can be optimized to withstand pressure (pressure hull) and the outer hull can be optimized to reduce drag. Also can place some "wet" equipment between the hulls saving space inside the pressure hull for business. Also said that outer hull protects against damage when subs surface in the arctic. In older subs, russies had a habit of welding the ring stiffeners *outside* the pressure hull. In a single hulled-design, you cannot do it as it would add drag.

Unkil had single hull design. Said the russies went for double-hull because they weren't good at welding and/or making big pressure hulls with all equipment inside. A high ranking Unkil navy officer was chastised when he wrote in a defense magazine that maybe Unkil should consider double hulled design. But unkil has a history of psy-ops (they pooh poohed russie habit of adding anechoic tiles, saying that american subs are so quiet that they dont need anechoic tiles. But then went and added them anyway).

negi · Post by **negi** » 01 Jul 2009 09:02

Double hulls being more quieter than the single hulls is a myth; the major source of acoustic signature is the Hydrodynamic drag and the propeller wake ; and both are governed by the tolerances and finish of a given surface itself (anechoic tiles/paint being a standard across the global sub fleet and for time being consider the design to be similar) . US had started using advanced 5 axis CNC milling machines for machining the highly skewed propeller blades long before Toshiba exported a few to the erstwhile USSR .

Given a strong and healthy industrial base supported by a well nourished university system I find it hard to believe that the defunct and neglected relics of the cold war era are superior to a fleet which receives upgrades on a periodic basis.

SanjibGhosh · Post by **SanjibGhosh** » 01 Jul 2009 09:50

very interesting, though it's a paki view.

A new hot-spot of rivalry
http://news.google.co.in/news/url?sa=t& ... cles01.asp

andy B · Post by **andy B** » 01 Jul 2009 10:09

SanjibGhosh wrote:very interesting, though it's a paki view.

A new hot-spot of rivalry
http://news.google.co.in/news/url?sa=t& ... cles01.asp

India’s preparation to dominate the Indian Ocean does not augur well for the region. India should concentrate more on resolving its disputes with its neighbours than bolstering its war capabilities. It should let Indian Ocean remain the zone of peace.

From the above article: I humbly disagree I think the steps taken by IN will indeed resolve disputes with its neighbours as it will out arm, out reach and out perform the neighbouring navies

vavinash · Post by **vavinash** » 01 Jul 2009 10:44

Obviously the porki is writing from his point of view, which as usual is skewed. He is afraid and rightly so that IN will cut off PLAN's ambition to dominate the IOR. Infact IN is not concentrating on IOR alone. Persian gulf, South china sea and red sea are also areas of interest to us. Ship berthing rights in Oman scare the crap out of porkis, now if IN had the same in vietnam chinks will also be worried.

Arun_S · Post by **Arun_S** » 02 Jul 2009 02:54

andy B wrote:
SanjibGhosh wrote:very interesting, though it's a paki view.

A new hot-spot of rivalry
http://news.google.co.in/news/url?sa=t& ... cles01.asp

India’s preparation to dominate the Indian Ocean does not augur well for the region. India should concentrate more on resolving its disputes with its neighbours than bolstering its war capabilities. It should let Indian Ocean remain the zone of peace.
From the above article: I humbly disagree I think the steps taken by IN will indeed resolve disputes with its neighbours as it will out arm, out reach and out perform the neighbouring navies

Cut-piece Pakistan and Indian Navy ensure peace in Indian Ocean.
Indian Ocean is and will remain "zone of peace".