INS Vishal (IAC- II) Aircraft Carrier - Flattop or Ski Jump

archie

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But then in the old system the heat was basically waste heat from the reactors of which you had something like 2/4/8 reactors in a USN CVN. Basically many pipes and hydraulics took the spare unusable energy from 2/4/8 places to say 4 catapults.
Waste heat from any steam power genration system is steam at nearly atmospheric pressure.. what sort of energy recovery are you talking about.. steam generated for steam caturpults are high pressure sustained pressures that allow fo the ram to go the full length.

The reduction in complexity is from the fact that you just needed to route the pipes and add control valves..

In EMALs it becomes a whole load of magnetizing coils and power routing circuits and this whole list has to be EMP protection from being affcted or causing trouble in the other electronics . Pls explain if there is someother factor that affects it
 

arnabmit

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Does anyone realize that getting EMALS is the first step to getting rail gun tech? The capacitor banks and the power source of both uses similar & parallel tech.
 

Abhijeet Dey

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Aah.......... Electromagnetic rail gun technology will be a good addition to India's future arsenal. India should go for it.
 

Yumdoot

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Waste heat from any steam power genration system is steam at nearly atmospheric pressure.. what sort of energy recovery are you talking about.. steam generated for steam caturpults are high pressure sustained pressures that allow fo the ram to go the full length.

The reduction in complexity is from the fact that you just needed to route the pipes and add control valves..

In EMALs it becomes a whole load of magnetizing coils and power routing circuits and this whole list has to be EMP protection from being affcted or causing trouble in the other electronics . Pls explain if there is someother factor that affects it
'Waste heat at atmospheric pressure' presupposes a normal plant for electricity generation.

A carrier plant has to provide steam and water for multiple uses at different temperatures like - boiler-turbines, catapult system, condensors for feed water, I think also the warm water for other uses on the ship. The turbines I think start working at around 280 degree celisus at 600 psi. The Catapult is a separate system and cannot be directly slaved to the boilors for operational reasons. For example you could be on full speed and yet not launching aircrafts so during this time it makes no sense to prim the catapult. The catapults are run by the slightly lower temperature steam (IIRC 230 degree celcius) but even this has to be achieved in steps in a Wet Steam Accumulator. Wet implies hot water is first injected into these Accumulators to avoid the accumulator walls cracking up from hot steam should it be released straight away into these accumulators. I presume Wet also implies that these accumulators work like our kitchen pressure cookers, only they have a lot of water in it to keep up the steam pressure. I doubt if they are ever going to keep the Accumulators on steam only. This Wet/hot water from the feed system is continually fed into these accumulators.

Final water and steam that is not usable in any useful manner ends up in condensors to be used again in the heat exchangers.

Slightly different from land based plants.
 

archie

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'Waste heat at atmospheric pressure' presupposes a normal plant for electricity generation.

A carrier plant has to provide steam and water for multiple uses at different temperatures like - boiler-turbines, catapult system, condensors for feed water, I think also the warm water for other uses on the ship. The turbines I think start working at around 280 degree celisus at 600 psi. The Catapult is a separate system and cannot be directly slaved to the boilors for operational reasons. For example you could be on full speed and yet not launching aircrafts so during this time it makes no sense to prim the catapult. The catapults are run by the slightly lower temperature steam (IIRC 230 degree celcius) but even this has to be achieved in steps in a Wet Steam Accumulator. Wet implies hot water is first injected into these Accumulators to avoid the accumulator walls cracking up from hot steam should it be released straight away into these accumulators. I presume Wet also implies that these accumulators work like our kitchen pressure cookers, only they have a lot of water in it to keep up the steam pressure. I doubt if they are ever going to keep the Accumulators on steam only. This Wet/hot water from the feed system is continually fed into these accumulators.

Final water and steam that is not usable in any useful manner ends up in condensors to be used again in the heat exchangers.

Slightly different from land based plants.

Ofcourse the implementation of the boiler is way diffrent in a ship vs at land operating principle is the same.. Size considerations come into play .

The steam chest/drum/accumulator/header is all presnt to store the enery and absorb any variations in usage patten and usually a singel boiler can supply multiple steam headers for diffrent purposes and at diffrent requirments

The point i am saying was its not waste heat from the boiler but energy has to be specifically expended to genarate the required quality

Wet/ Dry steam is nothing by moisture conent in steam.. Wet steam is one that has mosture (the white smoky stuff) Drysteam is what is used in Turbines and actual energy extraction systems ..that is colourless and deadly at pressure and temprature.. If you look at a steaming pressure cooker you will find a smokeless vapor near the nozzel and as it cools and expands you will see the smokey condensation (still a gas an called steam)

https://en.wikipedia.org/wiki/Superheated_steam
http://www.tlv.com/global/TI/steam-theory/types-of-steam.html
 

akshay m

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it seems that the RFI for INS Vishaal as a hoax created by the media, DCNS has not yet got the RFI

remember that the RFI was supposed to be answered by today

my journalist friend from navyrecog. says this
and i quote him

Remember that LoR supposedly sent by Indian MoD last week with 1 week delay...
Turned out to be Indian media BS (oncee again)...

I was at a press conference with DCNS CEO yesterday and I asked him about it:
this was the answer

-------------------------------------------------------


IAC-2 aircraft carrier for the Indian Navy

During the press conference, Navy Recognition asked Hervé Guillou about the Letter of Request supposedly submitted last week by the Indian Ministry of Defense for IAC-2 (indigenous aircraft carrier number 2). DCNS CEO started his answer with humor: "The mail must be slow, we are still waiting for it". Hervé Guillou then explained "It is clear that India has an aircraft carrier need and globaly a need for about 200 new vessels of all types until 2030. But regarding the aircraft carrier, the program is not as advanced as reported in the Indian press. We are discussing with the Indian Navy and it is clear that DCNS is at the forefront of the few companies able to be a supplier in this field. We are very interested in this matter, but it has not started yet".Finally, asked about the local partners, Herbé Guillou explained that DCNS has already worked closely for other projects with Reliance (Pipavav) and Mazagon Dock Limited.



heres the link
http://www.navyrecognition.com/index.php?option=com_content&task=view&id=2932





so all this head scratching for nothing,
which was the idiot journalist who created this imaginary RFI

GOD ONLY KNOWS WHAT'S WRONG WITH INDIAN MEDIA:crying::doh::frusty::sad::smash:
 
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Rowdy

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WANT

............................................
 

Prashant12

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Indian Navy considering Nuclear propulsion for Aircraft Carriers







New Delhi. The Indian Navy’s Design Bureau is favourably considering nuclear propulsion for the second time, and possibly a third indigenous aircraft carrier.




Although the final decision is yet to be taken, reliable sources told India Strategic that the Navy and the country’s nuclear scientists have drawn sufficient experience from their success in installing nuclear propulsion in Arihant, the country’s first SSBN (or nuclear propelled nuclear armed) submarine, and that is encouraging them to replicate the technology for indigenous aircraft carriers.

Right now, according to Chief of Naval Staff Admiral Robin Dhowan, the Naval Design Bureau (NDB) is working towards designing a 60,000 to 65,000 tonnes aircraft carrier, and that two major systems under consideration are nuclear propulsion and the new generation aircraft launch system, EMALS, from the US General Atomics. But there is no final decision yet on either.

India’s first indigenous aircraft carrier, IAC-I or Vikrant, is under construction at the Kochi Shipyard for delivery by end-2018, and it is to be propelled by four LM2500 gas turbine engines from the US GE. Nuclear power is being considered for the second, called IAC-II and likely to be named Vishal. It is planned for induction in 2029.




There is also the strong possibility of another indigenous carrier, IAC-III. While the IAC-I has a ski jump to launch aircraft, IAC-II and IAC-III will likely use the EMALS to catapult aircraft from short distances of the carrier decks.

The Indian Navy is looking at three aircraft carriers to ensure 24 x 7 operations with two Carrier Battle Groups. Three carriers are required as one of them will be under periodic maintenance and refits, and accordingly unavailable.

At present, the Indian Navy has Russia-supplied INS Vikramaditya since 2013, and it should be in service for about 30 to 35 years. India will need its third indigenous carrier by then, and it may be noted, it takes some 10 years to build it even with new modular construction practices.




Both INS Vikramaditya and IAC-I share the ski jump system to launch Russian-made MiG-29K aircraft. The EMALS will be much more efficient and powerful to launch different aircraft in moments with the flick of a switch. The US Navy is using the system for its new generation carriers, the Gerald R Ford (under construction) and John F Kennedy.

As for the IAC-II, sources told India Strategic that the Ministry of Defence (MoD) is set to initiate the first formal step towards according its official sanction by allotting funds to authorise and complete a study on requirements. The second step, a big one, is likely within 2016 in the form of Acceptance of Necessity (AoN). That will mean the official go-ahead from the Government to start work and funding will be allotted in accordance with the pace of development and construction.

Notably, while the US Government is already working on sharing the EMALS (Electromagnetic Aircraft Launch and Recovery System) technology with the Indian Navy, development and complex installation of nuclear propulsion will have to be done by Indians themselves. That is where the success in installing nuclear propulsion in Arihant using low enriched uranium (LEU) offers the incentive and inspiration.




The NDB and scientists from DRDO (Defence Research and Development Organisation) and BARC (Bhabha Atomic Research Centre) are systematically coordinating in this regard.

Notably again, the US carriers use bomb grade highly enriched uranium (HEU) after mastering the technology decades ago. The US Navy is the only one to do so, and apparently will be unwilling to share this expertise. HEU-propelled vessels have big advantage as they can go on for 20 to 40 years or more while LEU-propelled ships have to be opened and refueled every five years or so.

Significantly, Arihant has successfully completed several propulsion and diving trials, and right now, it is conducting a series of final tests to launch unarmed missiles from different depths before its likely induction in the coming few weeks. Subject to their success, it will be given a warship pennant number, declared operational, and then cleared for participation in the International Fleet Review (IFR) scheduled for February 2016.




Admiral Dhowan has expressed hope in this regard, but understandably has been noncommittal as even minor tests on board nuclear vessels are critical and nothing is accepted without total success, notwithstanding any time delays.

The Indian Navy already has clearance to build six SSN (nuclear propelled but not nuclear armed) submarines, and indications are that two to three more SSBN Arihant class vessels are also under different stages of planning and construction, and that they will be larger, and with more powerful nuclear reactors than that of Arihant.

Progression to building nuclear reactors for aircraft carriers is logical particularly as fossil fuel powered vessels are dependent on continuous supply of oil irrespective of the growing cost factors as well as the emerging threats in the Indian Ocean.

China, for instance, has acquired Gwadar from Pakistan to serve both as a commercial port and a naval base, becoming the first foreign power to have this facility so near the Indian shores and the strategic Strait of Hormuz from where nearly half the world’s oil comes through.

The US also has a major base in the Indian Ocean, but about 2400 km from India’s southern tip in Tamil Nadu.

http://www.indiastrategic.in/topsto..._Nuclear_propulsion_for_Aircraft_Carriers.htm
 

Gessler

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Which is better and cheaper? Brahmos Hypersonic missile (Under development) or US Navy's Electromagnetic Rail Gun?
The difference between a Railgun and a Hypersonic CM is like the difference between a dumb bomb and a 'smart' bomb. BrahMos-II is the smart bomb.

The advantage with CMs is that you can control how you want to deal with the target - what speed would be optimal, what path to take, what maneuvers to perform etc. Plus the missile would be able to see and lock onto it's own targets once it's close enough. Investing in a CM platform also means a lot of possible applications for the technology - ship, air, submarine or even land-launched versions can be developed to suite certain tactical needs. Railgun tech can also be diversified, but they are more linear.

Problem with Railguns is that they are little different from existing shipborne guns. They just manage to hit targets a lot farther, a lot quicker than before. As @Rowdy said, the operational cost of a railgun will be cheaper as the ammo are basically nothing but bolt projectiles.

For better comparison, railguns are like standard tank ammo (sabot, AP rounds etc.) while hypersonic CMs are like tank-launched ATGMs. Both are useful and capable in their own departments. I'd say any modern Navy with huge ambitions (like IN) would require both types of weaponry.

However if you say I can only have one, and that cost is not an issue, then I'll definitely go for Hypersonic CMs.
 

Chinmoy

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The difference between a Railgun and a Hypersonic CM is like the difference between a dumb bomb and a 'smart' bomb. BrahMos-II is the smart bomb.

The advantage with CMs is that you can control how you want to deal with the target - what speed would be optimal, what path to take, what maneuvers to perform etc. Plus the missile would be able to see and lock onto it's own targets once it's close enough. Investing in a CM platform also means a lot of possible applications for the technology - ship, air, submarine or even land-launched versions can be developed to suite certain tactical needs. Railgun tech can also be diversified, but they are more linear.

Problem with Railguns is that they are little different from existing shipborne guns. They just manage to hit targets a lot farther, a lot quicker than before. As @Rowdy said, the operational cost of a railgun will be cheaper as the ammo are basically nothing but bolt projectiles.

For better comparison, railguns are like standard tank ammo (sabot, AP rounds etc.) while hypersonic CMs are like tank-launched ATGMs. Both are useful and capable in their own departments. I'd say any modern Navy with huge ambitions (like IN) would require both types of weaponry.

However if you say I can only have one, and that cost is not an issue, then I'll definitely go for Hypersonic CMs.
I do totally agree with you. Railgun would be effective at LOS whereas CM's are effective at long distances. Railgun is a good weapon against other ships in Naval warfar, but when you have to strike an enemy position deep inland, you need to have a CM at your disposal.
 

archie

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I do totally agree with you. Railgun would be effective at LOS whereas CM's are effective at long distances. Railgun is a good weapon against other ships in Naval warfar, but when you have to strike an enemy position deep inland, you need to have a CM at your disposal.
I read somewhere that Railgun ranges are some 100-220 NM with projectile energy being in the ranges of 17 MJ

What is the range you say would be LOS 50 Nm??

http://techhydra.com/tech-news/military/us-navys-electromagnetic-railgun-weapon-technology/
 

Chinmoy

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I read somewhere that Railgun ranges are some 100-220 NM with projectile energy being in the ranges of 17 MJ

What is the range you say would be LOS 50 Nm??

http://techhydra.com/tech-news/military/us-navys-electromagnetic-railgun-weapon-technology/
Now what has been depicted and said in this article is true and might be effective. But lets ask few questions to ourselves first.
As depicted in the fig, the first half of its journey it would cover in Mach 7, agreed, but when it would reach its optimum height there would be no external force acting on it. It would be a free falling object in its own. That means all the Kinetic Energy it had on launch would change to Potential Energy. Its reentry would be equal to 10m/s irrespective of its mass. Now just imagine what would be difference between two two free falling object on a target, one of 10kg (23lbs) and another of 100kg(small CM). Its true that it would be hard to intercept a projectile fired from a railgun. But again a terrain hugging CM would too pose the same threat.
Again as per the article the range is said to be of 200 Nautical Mile or near about 370 kms, whereas with CM you could attack a target at 750 to 1000kms keeping yourself relatively safe from enemy fire. Moreover it had not mentioned about the design challenge. To give the required force of 223520Newton on the projectile to gain 7Mach, you need serious electric power. Moreover there is the challenge to keep the conductors cool due to the immense heat it would generate once the projectile is fired.
Keeping all these design challenge apart, just take the simple case of impact. It would not be effective as an CM while you have to attack enemy inland. But yeah, if its another warship at 20 Nautical Mile distance, this 10kg projectile traveling at Mach 7 would sure do some damage apart from making a huge vent in it.
 

archie

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Now what has been depicted and said in this article is true and might be effective. But lets ask few questions to ourselves first.
As depicted in the fig, the first half of its journey it would cover in Mach 7, agreed, but when it would reach its optimum height there would be no external force acting on it. It would be a free falling object in its own. That means all the Kinetic Energy it had on launch would change to Potential Energy. Its reentry would be equal to 10m/s irrespective of its mass. Now just imagine what would be difference between two two free falling object on a target, one of 10kg (23lbs) and another of 100kg(small CM). Its true that it would be hard to intercept a projectile fired from a railgun. But again a terrain hugging CM would too pose the same threat.
Again as per the article the range is said to be of 200 Nautical Mile or near about 370 kms, whereas with CM you could attack a target at 750 to 1000kms keeping yourself relatively safe from enemy fire. Moreover it had not mentioned about the design challenge. To give the required force of 223520Newton on the projectile to gain 7Mach, you need serious electric power. Moreover there is the challenge to keep the conductors cool due to the immense heat it would generate once the projectile is fired.
Keeping all these design challenge apart, just take the simple case of impact. It would not be effective as an CM while you have to attack enemy inland. But yeah, if its another warship at 20 Nautical Mile distance, this 10kg projectile traveling at Mach 7 would sure do some damage apart from making a huge vent in it.
That again places the fact that CM's have a different cost and application while rail gun will expand the horizon of artillery to the extent of early versions of missiles and yet cost similar to an artillery shell. Further to this the height this shell reaches means it can maybe used as anti-aircraft provided tracking is good and the short being done stealthy ( The plane not knowing its been targeted )

Both the systems probably complement each other but not replace ..
 

Chinmoy

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That again places the fact that CM's have a different cost and application while rail gun will expand the horizon of artillery to the extent of early versions of missiles and yet cost similar to an artillery shell. Further to this the height this shell reaches means it can maybe used as anti-aircraft provided tracking is good and the short being done stealthy ( The plane not knowing its been targeted )

Both the systems probably complement each other but not replace ..
Yes......... both these systems are different and can't be compared. But again operating a Rail Gun is a costly game and what you save in projectile goes for your power generation and conductors which you need. Till date replacing the naval guns with rail guns is not a practical decision in my opinion. It still needs time to mature enough as a potent weapon system.
 

archie

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Yes......... both these systems are different and can't be compared. But again operating a Rail Gun is a costly game and what you save in projectile goes for your power generation and conductors which you need. Till date replacing the naval guns with rail guns is not a practical decision in my opinion. It still needs time to mature enough as a potent weapon system.
You do realise Power is one of the easiest to handle and generate in a warship.. handing live ammunition is way more difficult task and transferring them from safe zones to places that need them when you got to fire is a difficult task compared to just flipping some switches to start charging ,, You dont replace conductors every-time.. its probably every few hundreds of shots
 

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