Indian Navy News & Discussion - 22 April 2015

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Re: Indian Naval News & Discussion - 22 April 2015

Postby tsarkar » 08 Feb 2016 12:44

Singha wrote:I do not think IN has any envisaged any land attack role with these as the army seems to be receiving the later marks of brahmos for land attack and periodically tests them.

http://pib.nic.in/newsite/PrintRelease. ... lid=133898
23-December-2015 19:16 IST
Large Scale Fleet Exercises Conducted by Indian Navy in bay of Bengal and Andaman Sea...

...A wide range of weapons, including Surface to Surface missiles (SSMs), Surface to Air missiles (SAMs) and Land Attack Missiles (LAMs) were fired from various platforms.

16 BrahMos on Type 15A are mix of anti ship & land attack

...over a period of two weeks

Incase people think IN does only shows, parades & reviews.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Singha » 08 Feb 2016 14:16

CG is coming along well:

IBNlive

In the next three-four months, it is going to sign a contract with Hindustan Aeronautics Limited (HAL) for procuring 16 ALHs, official sources said.

It is also exploring options to buy 14 twin-engine heavy helicopters. The Coast Guard is eyeing Airbus's Eurocopeter but it may take a couple of years to actually acquire these as a proposal in this regard is pending with the Ministry of Defence.

"We have been looking to procure twin-engine helicopters that can help in making long trips in the sea. The current Chetak helicopters do not have the ability to go deep over the sea. The twin-engine helicopters can make longer trips.

"They can be used in areas where we don't have air strips, for instance, in Minicoy and many such places," said a senior government official.

Air assets have often played a crucial role in the Indian Coast Guard's operations. When the suspicious Pakistani boat carrying explosives blew itself up on the night of December 31, 2014, off the Gujarat coast, the operation was conducted jointly by the air and sea wings of the maritime security force.
The Coast Guard is also looking for six more Maritime Multi-mission Surveillance Aircraft. However, Coast Guard is waiting for the Indian Air Force to be ready with a proposal as it wants to buy the aircraft together.

"The Staff Qualitative Requirements (SQRs) of the Coast Guard and Air Force are same. So, we are waiting for their proposal to get ready and then we can buy it together.
However, the purpose of the two will be different and modifications to the aircraft will be done as per the requirements of the two forces," the official said.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Singha » 08 Feb 2016 14:20

the zumwalt must have truly massive magazine capacity to feed those shore attack guns.

Philip sir, imo trimarans and bimarans offer larger deck areas for the displacement and shallow draught for getting to island territories, at the expensive of smaller internal hull volume which might not be suitable for the role. hence despite many proposals no navy has deployed a LHD or CV in that format. their ability to handle really deep sea states might also not be so great.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Aditya G » 08 Feb 2016 15:16

ICG should buy more dhruvs in of the Eurocopter order to ensure denser sat coverage and overall higher availability. Anything long range should be handled by navy or by air force mi-17s

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Re: Indian Naval News & Discussion - 22 April 2015

Postby vina » 08 Feb 2016 16:21

MN Kumar wrote:Image


Shiver me Dhotis.. Some thing very very very wrong with this bicchar. A rectangular VLS box top should have rectangular cross sections all the way down to the base .

What are those two huge circular columns below the box top doing then ? Have the Yindoos gone bonkers?

I think all you folks in the counting game of 8 or 12 or 64 have all got it wrong. All I can think of is from my NCC days in the Madrassa , when the Sargent explained things this way.

"Dhich ij a Re Vol Vah!" . This cylinder rotates and brings the next round in line with the barrel! Have the cunning Yindoos put in a "Re Vol Vah" feed for those looong mijjiles so that, under the 8 deck lid Burkas , lurk far larger number of mijjiles I ask ?

From bicchar I think I see Brahmos, Klub and the blunt nosed Nirbhay , what is the 4th one with the pointy tip ? This seems like a univerjal launch system to me.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Neela » 08 Feb 2016 16:43


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Re: Indian Naval News & Discussion - 22 April 2015

Postby Austin » 08 Feb 2016 16:46

vina wrote:Image

From bicchar I think I see Brahmos, Klub and the blunt nosed Nirbhay , what is the 4th one with the pointy tip ? This seems like a univerjal launch system to me.


Variant of Klub from L to R in picture

Pointed One is Klub 91RTE2 VLS launched anti-submarine variant carries a torpedo , Brahmos Supersonic AshM , Klub 3M-54TE with Supersonic Terminal Dart last is 3M-14TE Klub LACM

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Re: Indian Naval News & Discussion - 22 April 2015

Postby John » 08 Feb 2016 17:18

vina wrote:What are those two huge circular columns below the box top doing then ? Have the Yindoos gone bonkers?

That's is from mother russia :D. That is the russian u vls, Kolkata and Rajput use L&T launcher. The cutout for L&T universal vertical launcher looks more traditional.

Karthik S wrote:am by no means a ship designer but feel in P15s, the cells could have been arranged in two 8*4 cells in fore and aft for a total of 64 missiles.

I share your dream but brahmos weights three times as much as TLAM incl the canister and currently there is no DDG that is capable of carrying 64 Brahmos. Even DDG 1000 would needs its main gun removed to carry that payload.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby vina » 08 Feb 2016 17:20

Austin wrote:Variant of Klub from L to R in picture

Pointed One is Klub 91RTE2 VLS launched anti-submarine variant carries a torpedo , Brahmos Supersonic AshM , Klub 3M-54TE with Supersonic Terminal Dart last is 3M-14TE Klub LACM


OK . Anyways, this universal launcher seems to be the Russian 3R14UKSK. Material is Russian, however, if anyone can read it, possibly can explain why they have circular columns below the rectangular top. It doesnt seem to make much sense ,and no one will do it unless there is a big purpose for it.

Ok. Now makes sense It makes even less sense. The missiles are arranged inside the circular columns, 4 missiles per column , no Re-Vol-Vah. The thing is, they have put a square lid on top of a round tube. They might have as well put round lid on it like a manhole/ hatch cover. By putting it in the circular columns, where it could have carried 4 missiles in each canister of 1150mm in dia meter, this circular column business cuts down the diameter of the missiles that can be carried by a significant factor. Makes even less sense. A more traditional rectangular cross section box possibly could have packed one more missile in each row for the same space as this design.

Universal Launcher for Brahmos and Klub
Image
Image

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Re: Indian Naval News & Discussion - 22 April 2015

Postby vina » 08 Feb 2016 20:32

Singha wrote:Image

Never really liked the Zumwalt , tumble homes are dangerous to stability(especially if it takes damage and it sinks few feet into the water the freeboard gets lowered) and are simply outdated as of some 120 years ago. If they needed to slope the sides for stealth, they should have done something like the absolutely fine lines of the Shivalik class, which is really a beautiful ship. A traditional flare followed by sloping inward would give you the end result that Zumwalt wanted without the compromise to space and stability which the tumblehome starting from (looks like even below ) the waterline making it look like an incandescent light bulb in cross section .

Compare this with the Shivalik's sections from the picture
Image

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Singha » 08 Feb 2016 20:56

the shivalik in a way is a semi-tumblehome

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Aditya G » 08 Feb 2016 21:06

^ Those are Talwars. Also, the inward slope is not on the hull

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Re: Indian Naval News & Discussion - 22 April 2015

Postby deejay » 08 Feb 2016 22:33

Aditya G wrote:ICG should buy more dhruvs in of the Eurocopter order to ensure denser sat coverage and overall higher availability. Anything long range should be handled by navy or by air force mi-17s


They are buying those for heavier lift capability not for range.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Aditya G » 08 Feb 2016 22:51

deejay wrote:
Aditya G wrote:ICG should buy more dhruvs in of the Eurocopter order to ensure denser sat coverage and overall higher availability. Anything long range should be handled by navy or by air force mi-17s


They are buying those for heavier lift capability not for range.


Why would they need that for sar?

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Re: Indian Naval News & Discussion - 22 April 2015

Postby sohamn » 08 Feb 2016 23:22

vina wrote:Compare this with the Shivalik's sections from the picture
Image


The ships in question in not Shivalik but Talwar class frigates. Look at the Gun and the Single RBU 6000 and A190 gun and Fregat radar mast, that should give you enough clue about what ship it is.

Shivalik cross section looks like

Image

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Re: Indian Naval News & Discussion - 22 April 2015

Postby deejay » 09 Feb 2016 07:59

Aditya G wrote:...

Why would they need that for sar?


I don't know why CG needs it but the heavier helicopters are for heavier lift and not greater range (necessarily). CG would like heavier lift for rescue ops, where greater lift capability in terms of equipment carried and number rescued could be higher is my guess. Most helicopter discussions focus on ASW but most helicopter ops are for rescue and relief. Air Sea Search and Rescue, CasEvac, etc are actual live ops regularly carried out and CG has a major role in both these ops over Indian waters. Presently, their capabilities are limited to Chetaks in terms of lift capability for CG.

In medium lift, Mi 8 family is not a favoured machine for over sea roles though IAF uses them.

In India, with the experience gained by private operators and Pawan Hans three major medium lift types were tried for offshore ops - Bell 412, EC 155 and Dauphin. Sikorsky S76 was used by only one operator for a short time. Mi 172 (a civil version of Mi 8) lost favour after a crash in sea flying for ONGC.

Out of these Bell 412 (EP) is the most favoured followed by EC 155 and both have plus and minus.

If you read the news posted for longer range twin engine helicopters are needed for which the Dhruv will suffice. The heavy lift mentioned is technically medium lift as I am not aware of Eurocopter making any Heavy Lift helicopters.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Shreeman » 09 Feb 2016 08:51

vina,

that post of yours made no sense at all. i am still scratching my head as to what could have been the reasoning there.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby K_Rohit » 09 Feb 2016 11:01

Austin wrote:
vina wrote:Image

From bicchar I think I see Brahmos, Klub and the blunt nosed Nirbhay , what is the 4th one with the pointy tip ? This seems like a univerjal launch system to me.


Variant of Klub from L to R in picture

Pointed One is Klub 91RTE2 VLS launched anti-submarine variant carries a torpedo , Brahmos Supersonic AshM , Klub 3M-54TE with Supersonic Terminal Dart last is 3M-14TE Klub LACM


If this is correct, then is this (the one with the talwar firing it) the first picture confirming the Anti Sub Klub in Indian armoury? Dont recall seeing that before

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Singha » 09 Feb 2016 12:06

businessinsider.in

"The government has given approvals for six new SSNs (nuclear attack submarines) earlier this year. We have started work but still are at the pen to paper stage," Vice Admiral P Murugesan, the Vice Chief of Naval staff said in response to a question by Economic Times.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby tsarkar » 09 Feb 2016 12:20

K_Rohit wrote:If this is correct, then is this (the one with the talwar firing it) the first picture confirming the Anti Sub Klub in Indian armoury? Dont recall seeing that before
Its the supersonic anti ship version. The ASW versions have a thicker lower booster that this missile doesn't have. The hump is behind & hidden from view. The gun is OTO SRGM so ship is Shivalik class

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Philip » 09 Feb 2016 12:36

4th missile Nirbhay?

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Yagnasri » 09 Feb 2016 12:43

Singha wrote:businessinsider.in

"The government has given approvals for six new SSNs (nuclear attack submarines) earlier this year. We have started work but still are at the pen to paper stage," Vice Admiral P Murugesan, the Vice Chief of Naval staff said in response to a question by Economic Times.


Great thing if we can make them faster.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby K_Rohit » 09 Feb 2016 13:06

tsarkar wrote:
K_Rohit wrote:If this is correct, then is this (the one with the talwar firing it) the first picture confirming the Anti Sub Klub in Indian armoury? Dont recall seeing that before
Its the supersonic anti ship version. The ASW versions have a thicker lower booster that this missile doesn't have. The hump is behind & hidden from view. The gun is OTO SRGM so ship is Shivalik class


Thanks. So we still wait for the confirmation of anti sub Klub with India

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Re: Indian Naval News & Discussion - 22 April 2015

Postby tsarkar » 09 Feb 2016 15:45

^^ Not purchased for two reasons

1. Designation & firing solution at those ranges. Typically ship based sonars give a firing solution at ranges covered by ship based 533 mm HWTs. For longer ranges, helicopter based dipping sonars and sonobuoys are used. However, helicopters carry their own torpedoes & depth charges to attack submarines. Hence using a helicopter sonar to designate a ship launched rocket boosted torpedo is redundant. Same for MPA that carry adequate sonobuoys and weapons.

US Ship Launched ASROC works similarly https://en.wikipedia.org/wiki/RUR-5_ASROC
After a surface ship, patrol plane or anti-submarine helicopter detects an enemy submarine by using sonar or other sensors, it could relay the sub's position to an ASROC-equipped ship for attack. The attacking ship would then fire an ASROC missile carrying an acoustic homing torpedo or a Nuclear Depth Bomb (NDB)

Relaying faces transmission losses + advertises ship/helicopter/aircraft position to enemy forces. We lost an IN Alize hunting PNS Hangor to Pakistani F-104 in 1971.

To compensate for the lack of accuracy of firing solution, ASROC used a Nuclear Depth Bomb. That is unusable for conventional war. Plus friendlies nearby could be impacted.

US SUBROC and Sea Lance were cancelled for the same reason. How will the submarine designate and calculate firing solution at long ranges
https://en.wikipedia.org/wiki/UUM-44_SUBROC
https://en.wikipedia.org/wiki/UUM-125_Sea_Lance

VL ASROC has a published range of 28 km that is similar to the range of modern HWT.
http://www.designation-systems.net/dusrm/m-139.html

US deleted HWT from their ships for VL-ASROC. We decided to keep HWT and not encumber the VLS.

2. The Russian LWT in the Klub ASW missile was a one-off and judged as not very capable to comparable torpedoes like WASS A244S or TAL.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Austin » 09 Feb 2016 16:37

^^ The problem in real world is the contact received from enemy subs last few minutes if you are lucky at medium ranges most of time the sub gets detected at closer ranges where assest might be in danger from subs, even if your assets detects this contacts and positively identifies it as enemy sub by the time your asset takes off to drop a torpedo the contacts would have dissapeared or your asset like Choppers or ASW aircraft might itself be vulnerable to enemy A2A assets.

A submarine or surface ship launched ASW missile like Klub with LWT will make the task of tracking , detection and identification and executing the weapon reaching at the designated area at shortest possible time without loosing contact of enemy sub which barely last few minutes.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby tsarkar » 09 Feb 2016 17:00

Your post is not very clear, Austin.

At a range of say 75 km, ship sonar cannot provide a firing solution for torpedo or missile.

A helicopter or MPA with Periscope search radar / MAD / Diesel Fume Detector / Sonobuoys possibly can.

The torpedo or depth charge dropped by helicopter will reach the detected submarine much faster than helicopter relaying data and thereafter missile launched from ship.

The helicopter is the best long range ASW asset. Which is why every Indian ship has Seaking sized deck.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Austin » 09 Feb 2016 17:23

^^ If say you get a target at 75 Km highly unlikely but assume or say 40 Km the ship sonar gives close approximate of the target and fires at the missile the torpedo falls at 1-2 Km of the target which the seeker of LWT is effective for searching and homing the target ,The advantage is the short time needed to react to a target that can just last few minutes before it gets lost , the disadvantage is the sensors of LWT are not effective beyond 2 km hence the distance from target where torpedo gets dropped is critical.

The sonar does not provide the entire firing solution because unlike a ship launched torpedo which is slow to reach the target and the target keeps moving the sonar does not keep tracking the target till the torpedo sonar gets active or passively acquires the target which is just few km in best case.

Most problem with modern sonar wrt submarine and it gets compounded is the acoustic quiteness of submarine keeps getting better and a Sea is naturally barrier and more natural ground for submarine to play the very short contact time between detection , acquiring and firing at the target , A enemy submarine can appear and dissapear multiple times for minutes and contact gets lost forever.

A helicopter is good for short distances if the ship can maintain contact with the target and guide the chopper close to it where a chopper sonar then requires it and can giude the torpedo. There are merits and demerits for both weapons

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Re: Indian Naval News & Discussion - 22 April 2015

Postby John » 09 Feb 2016 17:32

Philip wrote:4th missile Nirbhay?


That is Klub N, this is russian U VLS it won't be fitted on any new IN vessel perhaps for maybe any additional talwars procured.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby tsarkar » 09 Feb 2016 19:06

Austin, your post assumes ship's sonar effective at a certain range. I will not comment on that.

However there is a reason why Russian & Swedes still have mortars like RPK-8. There is a reason why 324 mm TT still arm most western ships. These weapons are matched to sensors giving accurate firing solutions.

Towed Array Sonar do allow detection and tracking at longer ranges, but are used in conjunction with helicopters. They provide the cueing to helicopters that track using sonobuoys and dipping sonars.. An ASW missile could be possibly used with TAS.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby raghava » 09 Feb 2016 19:55

tsarkar sir,

In the IN, is there a regular technical audit to see if the sonar(s) in ships are working according to specifications? Who is responsible for this maintenance and/or repair? The IN engineering arm or the OEM?

thanks in advance

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Re: Indian Naval News & Discussion - 22 April 2015

Postby vina » 09 Feb 2016 20:18

sarkar wrote:US deleted HWT from their ships for VL-ASROC. We decided to keep HWT and not encumber the VLS.

I though the torpedoes carried on the decks of ships these days is a LWT and not HWT , which seem to be carried more by subs. The days of firing a HWT out to 30 nm range from a surface ship is gone I would think and that is where the rocket topped with a LWT comes in handy, reaches the target much faster than a HWT fired from a ship would.

Also wanted to comment on your post earlier on the hull plating thickness and strength etc. See, it is like this. The shell of the ship is a strength member. It is not just a covering sheet to keep the water out. Now while large ships today would be fully longitudinally framed or mixed framed , most navy ships (leaving out the large carriers) would be still largely transversely framed or at best mixed framed. And in any case, irrespective of whichever type, the choice of plating gauge would have a bearing on the framing distance and the stringer gap distance. Stands to reason. The thicker plate would have higher strength and you wont need the closer frames as in a thinner sheet to have the same stiffness and the framing could be wider.

So yeah, the structural efficiency (given a choice of grade of steel) is an optimisation between the framing and the stringers and of course, the sub-divnisioning and everything.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Austin » 09 Feb 2016 21:27

tsarkar wrote:Austin, your post assumes ship's sonar effective at a certain range. I will not comment on that.

However there is a reason why Russian & Swedes still have mortars like RPK-8. There is a reason why 324 mm TT still arm most western ships. These weapons are matched to sensors giving accurate firing solutions.

Towed Array Sonar do allow detection and tracking at longer ranges, but are used in conjunction with helicopters. They provide the cueing to helicopters that track using sonobuoys and dipping sonars.. An ASW missile could be possibly used with TAS.


I agree the range I am quoting is too generous and in a very favourable condition for Surface Ship Sonar and unfavourable for subs , I was just trying to point that standoff Rocket/Torpedo these days are not unreliable as systems deployed in 70/80's that tend to have much longer range and larger cal torpedo but for time sensitive contacts with very short detection/tracking and lack of other assets in the air to support ASW ops , systems like Klub/Torpedo can give an additional/effective means to execute weapons control over ranges that are much beyond the range of any torpedo to execute due to time/distance and contact availability.

There are other tactical advantage of such systems like a torpedo underwater being actively tracked by LFATAS though effective against silent contacts alerts the contacts and it can take evasive action till such time a torpedo achieves a hit while in case of rocket assisted torpedo the contact is not aware its under attack till the torpedo hits the water and starts active/passive search giving it a narrow windows to escape

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Singha » 10 Feb 2016 07:34

questions for tsarkar sir.

1) ship is moving head on to these 100 foot waves (brown pants for me) .... is it safe for cargo ships or warships to move at an angle also, or its always head on or tail on for such sea states?
2) if due to freak conditions the distance between successive peaks is less than ships length , is there a danger both ends could float up and the trough below the middle could break or crack the ships back? or are ships designed for such bending loads ? I read that CVNs sailing like this flex upto 3 feet up and down in the middle....
3) can smaller corvettes, FFGs tackle such sea states and still operate ?
4) does such sea and rain conditions degrade the radars, ASMs, decoys(aerosol clouds/chaff) and SAMs?
6) I read in alistair mclean novels of rescues being helped by ships dumping diesel layer into the area to 'calm the waves' - is that legit?
7) can the kind of enclosed automated deployment fibreglass n inflatuble lifeboats most ships have nowadays (seen in captain philips movie) survive in these conditions?
8) should the ship apply full power to ride these head on or throttle back?
9) if the engine fails for any reason and the ship starts wallowing , will a 5000t ship survive this?
10) to attempt a basket rescue in these conditions would a Dhruv manage or you want a bigger meatier EC725/Sh60/Merlin for it?
11) are oil tankers filled with lighter than water oil and strong compartmentalization + double hull literally unsinkable? I mean they could ride low in the water but will not go down.
12) do we get such conditions in arabian sea or bay of bengal?



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Re: Indian Naval News & Discussion - 22 April 2015

Postby vina » 10 Feb 2016 08:52

1) ship is moving head on to these 100 foot waves (brown pants for me) .... is it safe for cargo ships or warships to move at an angle also, or its always head on or tail on for such sea states?

100 ft waves are very rare. For commercial shipping, WNA (Winter North Atlantic) is the ginger weather with significant wave heights upto 30m (UK, Iceland, Greenland, Nova Scotia gap). Yes, ships operate in those weathers, with a loading line designated for that. Broaching/Quartering seas are okay for today's large cargo ships and shouldn't be too much of a bother (size matters) . In a storm, you will always turn into the waves . Following seas are among the most dangerous in heavy weather, with.

2) if due to freak conditions the distance between successive peaks is less than ships length , is there a danger both ends could float up and the trough below the middle could break or crack the ships back? or are ships designed for such bending loads ? I read that CVNs sailing like this flex upto 3 feet up and down in the middle....

No way. The ships are always built to a registrar's (ABS, LLoyds, Bureau Veritas ) guidelines and certified or it will not be insured. Those guidelines cater to all the kinds of conditions you talk about in the code.

3) can smaller corvettes, FFGs tackle such sea states and still operate ?

Of course yes, and not just militray, even fishing boats and trawlers. They take a big beating and undergo far more violent motions than a large cargo ship of course.
4) does such sea and rain conditions degrade the radars, ASMs, decoys(aerosol clouds/chaff) and SAMs?

Radars No. Rest I dont know.
6) I read in alistair mclean novels of rescues being helped by ships dumping diesel layer into the area to 'calm the waves' - is that legit?

No way. Waves are due to wind action (given a large enough "fetch", ), putting diesel on surface does nothing to waves. Yeah, the only thing it might do is to lighten a ship.
7) can the kind of enclosed automated deployment fibreglass n inflatuble lifeboats most ships have nowadays (seen in captain philips movie) survive in these conditions?

Yes. All life boats by SOLAS code have to be able to survive such conditions and areself righting as well . Even if they turn turtle, they will right themselves. They also have rations and emergency supplies and radios, batteries and even some of them have facility to catch rain water.

8) should the ship apply full power to ride these head on or throttle back?

Head on waves, you will make heavy way, so will take more power than usual. Following sea, you better ease up ,the motions in the rear will be violent (including instantaneous loss of stability, consider case, when ship speed is exactly same as wave speed and the ship is suspended in time with crests at the bows and stern and trough amidships , the ship will capsize) with screws coming out of the water or sections of prop clearing the water and slamming back in (shock loading of that guaranteed to break the screws and the associated shafts).

9) if the engine fails for any reason and the ship starts wallowing , will a 5000t ship survive this?

Probably. You really want to keep the bows pointed into the waves in such conditions.
10) to attempt a basket rescue in these conditions would a Dhruv manage or you want a bigger meatier EC725/Sh60/Merlin for it?

Range & Payload you need a big dedicated maritime helicopter with auto hover on a certain height. Impossible to hold station and hover manually in those kind of conditions. You want to fly a long distance, grab everyone and fly back.

11) are oil tankers filled with lighter than water oil and strong compartmentalization + double hull literally unsinkable? I mean they could ride low in the water but will not go down.

Yes, but that is true of most large cargo ships of any kind. Traditionally because of inherent safety, oil tankers were single hulled. What made oil tankers double bottom hull was pollution due to oil leakage if it gets holed for any reason (think Exxon Valdez) . So regulations mandated double bottom (and sides as well) for that. However, that LOWERS stability compared to the single hull design of old.
12) do we get such conditions in arabian sea or bay of bengal?

Probably in a super cyclone kind of thing that hit Orissa long ago. As a general rule , No.
Also watched the clip you posted. It doesn't seem like a normal sized cargo ship of today, but rather an ocean going service vessel /tug/tender of some sort. Even for that, the bow gets dunked underwater only twice. So not really the big enchilada. That big enchilada is when a 80,000 DWT bulk cargo carrier or a container ship having waves breaking over it's forecastle in regular intervals. That is when things are pretty rough.

Now most conventional ships with a flared bow will be built with a shear as well (basically, the side view will show a rising line from midships to the stem)so that the ship has good sea keeping. With a bow piercer like the Zumwalt, riding these kinds of storms will be a miserable and nasty experience, very analogous to a submarine trying to ride the waves , which a submarine will never do of course, it will take in ballast and submerge and ride out the weather with nary a problem underwater.
Last edited by vina on 10 Feb 2016 09:38, edited 1 time in total.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Singha » 10 Feb 2016 09:36

thanks...I have a new respect for the men and women who design and operate these things. may not look iphone pretty but rugged and industrial grade kit.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Philip » 10 Feb 2016 12:53

Required also for the IN.A revolutionary unmanned anti-mine/sub hunter.It shouldn't be too difficult to obtain since we have excellent relations with Israel.
http://www.jpost.com/Israel-News/Israel ... oes-444270
Israel Navy will likely be first client to order Elbit Systems' Seagull unmanned surface vehicle.
Seagull USV

The Seagull USV. (photo credit:ELBIT SYSTEMS)

Elbit Systems unveiled on Monday a new, autonomous unmanned surface vehicle that can wage antisubmarine missions by firing small torpedoes, as well as detect and blow up submerged mines by sending robots and interceptors deep underwater.


The Seagull autonomous multi-mission USV is a two-vessel system that has been developed over the past three years, Elbit officials said at Haifa Port, where the platform carried out some maneuvers on the water.

Ofer Ben-Dov, vice president of the Naval Systems Business Line, Unmanned Aircraft Systems at Elbit’s ISTAR Division, described the platform as a “revolution.”

“We are witnessing the proliferation of submarines, both conventional and nuclear, and sea mines. The cost and risk of dealing with these threats is high,” he said.

“We consider the Israel Navy and Defense Ministry to be advanced potential milestone clients.”

Other potential clients are in touch with Elbit as well.

“We would not have entered into this if we did not have a business plan, and if this did not cause much interest and amazement,” Ben-Dov added.

A submarine’s advantage lies in its covert presence, and radars are ineffective in discovering it, he said. Costly task forces, made up of sonar planes and helicopters, or frigates that cost hundreds of millions of dollars to build and operate, have traditionally been used to detect and neutralize such threats.

Seagull, which costs only tens of million dollars (for two vessels, an array of payloads and a ground control station) “changes the balance of power between defender and submarine. The submarine is always used offensively, either to gather intelligence or to attack.”

When it comes to mine detection, “we take the sailors out of the mine field,” Ben-Dov said.


One vessel carries two sonar sensors located in the bow and stern, and if suspected mines are detected, a second vessel lowers a robot into the water, to investigate further.

“This is a robotic boat that sends other robots into the water,” he added.

Once a threat is confirmed, the USV will launch a wire-guided torpedo that receives sonar guidance data from the USV. As it closes in on the target, it switches on its own electro-optic camera for the approach; when very near the target, it detonates itself.

The two-vessel format enables Seagull to be fitted with payloads for antisubmarine warfare, countermining (including floating mines, which can be shot and blown up), sea and port security missions, or electronic warfare missions.

The USV is equipped with two main engines and two thrusters, allowing it to achieve speeds of up to 32 knots, and to turn on the spot. Elbit officials said it is highly autonomous, and can circumvent obstacles while adhering to international sea passage rules, even if the command link is cut. A satellite link can keep controllers in touch with the USVs beyond the line of sight communications, and they can operate continuously for up to 96 hours. A remote-controlled 12.7-mm. machine gun is attached to the bow.

“In recent years, we have identified a growing trend towards sea-based activities,” said Elad Aharonson, executive vice president and general manager at Elbit’s ISTAR Division.

In Israel’s case, he added, the ability by the defense establishment to secure the country’s air and sea spaces against enemy threats means that hostile states and terrorist organizations could seek the underwater arena as the next place to try to mine ports and launch attacks. The Seagull “becomes an asymmetrical advantage for those who use it” against submarines and sea mines.

Both vessels can be controlled from manned ships or from the shore, and the system is fully operational.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Gyan » 10 Feb 2016 13:06

vina wrote:
sarkar wrote:US deleted HWT from their ships for VL-ASROC. We decided to keep HWT and not encumber the VLS.

I though the torpedoes carried on the decks of ships these days is a LWT and not HWT , which seem to be carried more by subs. The days of firing a HWT out to 30 nm range from a surface ship is gone I would think and that is where the rocket topped with a LWT comes in handy, reaches the target much faster than a HWT fired from a ship would.

Also wanted to comment on your post earlier on the hull plating thickness and strength etc. See, it is like this. The shell of the ship is a strength member. It is not just a covering sheet to keep the water out. Now while large ships today would be fully longitudinally framed or mixed framed , most navy ships (leaving out the large carriers) would be still largely transversely framed or at best mixed framed. And in any case, irrespective of whichever type, the choice of plating gauge would have a bearing on the framing distance and the stringer gap distance. Stands to reason. The thicker plate would have higher strength and you wont need the closer frames as in a thinner sheet to have the same stiffness and the framing could be wider.

So yeah, the structural efficiency (given a choice of grade of steel) is an optimisation between the framing and the stringers and of course, the sub-divnisioning and everything.


Against Surface targets, a ship can use Cruise missiles, hence no need of HWT. And against submarines (and even against ships), a combo of Helo + LWT can be used to increase the range of reach.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby vina » 10 Feb 2016 13:07

Singha wrote:thanks...I have a new respect for the men and women who design and operate these things. may not look iphone pretty but rugged and industrial grade kit.

This one is a real dhoti shiver.Look at the size of the boiling angry waves topped in white . The ship (must be upwards of 3000 TEU containership here) is tossed around and rolled like toy in a quartering sea.



This one is a maha dhoti shiver is probably
Last edited by vina on 10 Feb 2016 13:23, edited 1 time in total.

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Singha » 10 Feb 2016 13:19

I think it is rolling more as the waves are side on.
some of the latest container ships are so large, the traditional superstructure & single funnel at the back is no longer enough....no sir these bad cats take around 10,000 x 40ft containers and are about 18 containers wide and have the bridge in the middle for a clearer view of the bow
https://www.youtube.com/watch?v=IUxSGwmWcq4

have to wonder how top heavy it is ... perhaps the loading plan puts the heaviest containers at the bottom and the usual clothes/toys/shoes on top .... still, containers are lost in storms and contents wash up on shore for beachcombers

Image

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Re: Indian Naval News & Discussion - 22 April 2015

Postby Singha » 10 Feb 2016 13:24

a merchant ship did crack its backbone off yemen
https://www.youtube.com/watch?v=SR1xNHWlEeM


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