INS Vishal might be nuclear-powered aircraft carrier : Naval Design Bureau

[Penguin]

Can someone explain why a 40k ton ship is only 25200 ton after fabrication.?
@sancho @Gessler @Penguin


Cochin Shipyard stares at a lean order book - The Hindu

IN GENERAL:

In modern maritime usage, "tonnage" specifically refers to a calculation of the volume or cargo volume of a ship. Tonnage should not be confused with "displacement", which refers to the actual weight of the vessel.

Gross tonnage is a function of the volume of all of a ship's enclosed spaces (from keel to funnel) measured to the outside of the hull framing. Net tonnage is based on a calculation of the volume of all cargo spaces of the ship. It indicates a vessel's earning space and is a function of the moulded volume of all cargo spaces of the ship. Gross register tonnage represents the total internal volume of a vessel, where one register ton is equal to a volume of 100 cubic feet (2.83168 m3), a volume that, if filled with fresh water, would weigh around 2,800 kg or 2.8 tonnes. Net register tonnage i the volume of cargo the vessel can carry—that is, the gross register tonnage less the volume of spaces that do not hold cargo (e.g., engine compartment, helm station , and crew spaces, again with differences depending on which port of country does the calculations). It represents the volume of the ship available for transporting freight or passengers

Tonnage - Wikipedia, the free encyclopedia

A ship's displacement or displacement tonnage, a term usually applied only to naval vessels, is the weight of the water that a ship displaces when it is floating. The term is defined ordinarily such that the ship's fuel tanks are full and all stores are aboard. Another way of thinking about displacement is the weight of the water that would spill out of a completely filled container were the ship placed into it.

A number of synonymous terms exist for this maximum weight, such as loaded displacement, full load displacement and designated displacement

Full or deep load or loaded displacement
Full load displacement and loaded displacement have almost identical definitions.
Full load displacement is defined as the displacement of a vessel when floating at its greatest allowable draft as established by classification societies. For warships, an arbitrary full load condition is established.
Deep load condition means full ammunition and stores, with most available fuel capacity used.
Loaded displacement is defined as the weight of the ship including cargo, passengers, fuel, water, stores, dunnage and such other items necessary for use on a voyage, which brings the ship down to its load draft.
Standard displacement
The standard displacement, also known as Washington displacement, is defined as the displacement of the ship complete, fully manned, engined, and equipped ready for sea, including all armament and ammunition, equipment, outfit, provisions and fresh water for crew, miscellaneous stores, and implements of every description that are intended to be carried in war, but without fuel or reserve boiler feed water on board. The omission of fuel and water was to avoid penalizing the British, who had great global commitments and required greater fuel loads, and especially the United States, which had global commitments almost as great but with fewer bases to provide fueling than the Royal Navy.
Light displacement
Light displacement (LDT) is defined as the weight of the ship excluding cargo, fuel, water, ballast, stores, passengers, crew, but with water in boilers to steaming level.

Normal displacement
This rare term has been used to mean the ship's displacement "with all outfit, and two-thirds supply of stores, ammunition, etc., on board.

http://en.wikipedia.org/wiki/Displacement_(ship)

So, we really should be looking into WEIGHT i.e. DISPLACEMENT. Next you need to determine f the 40k is light, standard or full load displacement. And you need to determine what the 24k is, in that respect.

THIS SPECIFIC ARTICLE:

The hull shop, having a capacity to fabricate over 1,500 tonnes every month, has been under-utilised since July last year for want of orders barring the fast patrol vessels (FPVs) for the Coast Guard which need just about 100 tonnes of fabrication apiece and a platform supply vessel for Norwegian owners.
While outfitting and shafting have gathered momentum on Vikrant, the carrier is gearing up for its launch from the building bay by the end of the year, indicate sources.
“The carrier only has about 1,200 tonnes of steel left to go on the structure. Right now, it has a tonnage of about 24,000.”
The yard was pinning it hopes on bagging meaty defence orders like at least one of the four Landing Platform Docks (LPDs), each weighing 20,000 tonnes, that the Indian Navy intends to procure.

Cochin Shipyard stares at a lean order book - The Hindu

I think the article IS referring to weight/displacement. Note furthermore:

The ship uses modular construction, with 874 blocks joined together for the hull. By the time the keel was laid, 423 blocks weighing over 8,000 tons had been completed. The construction plan called for the carrier to be launched in 2010, when it would displace some 20,000 tonnes, as a larger displacement could not be accommodated in the building bay. It was planned that after about a year's development in the refit dock, the carrier would be launched when all the major components, including underwater systems, would be in place. Outfitting would then be carried out after launch. As per the Cabinet Committee on Security (CCS), sea trials were initially planned to commence in 2013, with the ship to be commissioned in 2014.
...
On 29 December 2011, the completed hull of the carrier was first floated out of its dry dock at CSL, with its displacement at over 14,000 tonnes. Interior works and fittings on the hull would be carried out until the second half of 2012, when it would again be dry-docked for integration with its propulsion and power generation systems
...
In July 2013, Defense Minister A.K. Anton announced that Vikrant would be launched on 12 August at the Cochin Shipyard. The ship was launched by his wife, Elizabeth Antony, on 12 August 2013. Extensive sea trials are expected to begin in 2016 and the ship will be inducted into the navy by late 2018
According to Vice Admiral Robin Dhowan, about 83% of the fabrication work and 75% of the construction work was complete.
...
After the launch, Vikrant was re-docked for the second phase of construction, in which the ship will be fitted with various weapons and sensors, and the propulsion system, flight deck and the aircraft complex will be integrated

http://en.wikipedia.org/wiki/INS_Vikrant_(2013)
This bolded last bit in part explains the difference between 24k and 40k tons.

Aug 13, 2013
INS Vikrant will have approximate displacement (weight) of 18,500 tonnes at its launch.

India launches first indigenous aircraft carrier INS Vikrant: All you need to know - Firstbiz

So, during the last year about 5500 tons were added. 1200 tons more will be added. Then there may still be some difference, depending on the type of displacement the numbers are actually referrinf to. You need to have the same for both the 24k and the 40k or else compare apples and oranges. I'm inclined to believe 37.5-40k is full load displacement. Not so sure the 24k is that too (probably not, come to think of it). Anyway, you need to at least add the weight of various weapons and sensors, and the propulsion system, flight deck (notably ski-jump). And then add what it carries in terms of stores, ordnance, fuel for its own propulsion and power generation, fuel for its aircraft complement, some drinking water ....
http://www.freewebs.com/jeffhead/worldwideaircraftcarriers/vikrant.htm

 

[Penguin]

Example; Italian Cavour

The difference between full and unloaded is about 6500 tons, of which probably more than half due to fuels, with stores and ordnance (munition supplies) making up the rest. That 6500 tons is over 20% of the full load displacement.

Displacement:
21,160 tons unloaded,
22,290 tons standard,
27,500 (27,100?) tons full load,
> 30.000 tons expected at the end of service life

2,500,000 litres of diesel (for propulsion) > some 3000 tons
1,500,000 litres of fuel for planes and helicopters > some 1500 ton

Cavour - Light multirole Aircraft Carrier

 

[Penguin]

Other carrier examples:

Kitty Hawk class
Displacement:
60,933 tons light (75% of fld)
81,780 tons full load

Kuznetsov
Displacement:
43,000 tons (Standard)
55,200 tons (Full)
61,390 tons (Max-load)

Ulyanovsk
Displacement:
65,800 tons standard
75,000 tons full load

 

[Agent_47]

IN GENERAL:

In modern maritime usage, "tonnage" specifically refers to a calculation of the volume or cargo volume of a ship. Tonnage should not be confused with "displacement", which refers to the actual weight of the vessel.


Tonnage - Wikipedia, the free encyclopedia


http://en.wikipedia.org/wiki/Displacement_(ship)

So, we really should be looking into WEIGHT i.e. DISPLACEMENT. Next you need to determine f the 40k is light, standard or full load displacement. And you need to determine what the 24k is, in that respect.

THIS SPECIFIC ARTICLE:

Cochin Shipyard stares at a lean order book - The Hindu

I think the article IS referring to weight/displacement. Note furthermore:


http://en.wikipedia.org/wiki/INS_Vikrant_(2013)
This bolded last bit in part explains the difference between 24k and 40k tons.


India launches first indigenous aircraft carrier INS Vikrant: All you need to know - Firstbiz

So, during the last year about 5500 tons were added. 1200 tons more will be added. Then there may still be some difference, depending on the type of displacement the numbers are actually referrinf to. You need to have the same for both the 24k and the 40k or else compare apples and oranges. I'm inclined to believe 37.5-40k is full load displacement. Not so sure the 24k is that too (probably not, come to think of it). Anyway, you need to at least add the weight of various weapons and sensors, and the propulsion system, flight deck (notably ski-jump). And then add what it carries in terms of stores, ordnance, fuel for its own propulsion and power generation, fuel for its aircraft complement, some drinking water ....
http://www.freewebs.com/jeffhead/worldwideaircraftcarriers/vikrant.htm

So, as i understand
Vikrant
unloaded - 25200 tons
light =~32000 tons
Standard - 37500 tons
Full load =~40000 tons

Though the proposal to build a 20,000 ton Air Defence Ship (ADS) had been in the pipeline since the early 1990s, it received formal government approval only in January 2003. By then time, the vessel had doubled in displacement, to a 37,500 ton warship

INS Vikrant will displace 37,500-tonnes with a length of 260 metres long and a width of 60 metres. Maximum speed of the ship is announced at 28 knots

Vikrant-class / Indigenous Aircraft Carrier (IAC) / Air Defense Ship
Indigenous Aircraft Carrier INS Vikrant program update with Cochin Shipyard at Defexpo 2014

When comparing Vikrant ,Vikramaditya and Charles de Gaulle.
Displacement (full load) - Vikramaditya (45,400 tons )> Charles de Gaulle (42,000 tonnes) > Vikrant
Aircrafts carried - Charles de Gaulle (28-40) > Vikrant (30-35) > Vikramaditya (18+10)

 

[Rajaraja Chola]

It's called foresight.... With well thought out development plans, indigenous development yields more bang for the buck than imports can. If IAF would have owned the responsibility for all developmental work in Indian defense domain today, IAF sqdn strength would have matched the likes of PLAAF, with results and objectives at par with ISRO....

I think Indian Navy opts for maximum indeginisation due to variety of factors like the lack of funds. Navy always have got the less of defence expenditure than the AF and army, forcing it to look internal means. It did take a lotta years , but now thanks to Navy, Indian shipyards can do build quality vessels.
IAF on the other hands always had the funds on standby, in case a domestic varient got unsatisfied response. So it never really got serious in development of indigenous fighters.

 

[Penguin]

So, as i understand
Vikrant
unloaded - 25200 tons
light =~32000 tons
Standard - 37500 tons
Full load =~40000 tons

Yeah, that's about right. Except that 'unloaded' may more accurately be termed 'incomplete' (structurally complete but not completely fitted out). Essentially, since we're not dealing with steam-powered but with gasturbine powered ship, light displacement is unloaded.

 

[narcon]

Yeah, that's about right. Except that 'unloaded' may more accurately be termed 'incomplete' (structurally complete but not completely fitted out). Essentially, since we're not dealing with steam-powered but with gasturbine powered ship, light displacement is unloaded.

What are you talking? Steamship of 1800 centuries? Which ship do you see as steam powered baby?

 

[Penguin]

What are you talking? Steamship of 1800 centuries? Which ship do you see as steam powered baby?

Well, why don't you read a few posts before, where there is a discussion of the terms light, standard and full load displacement. The definition of those terms goes back to the 1920s, when it applied to cruisers and dreadnoughts (steampowered).

Light displacement
Light displacement (LDT) is defined as the weight of the ship excluding cargo, fuel, water, ballast, stores, passengers, crew, but with water in boilers to steaming level.

Source: https://defence.pk/threads/ins-vishal-might-be-nuclear-powered-aircraft-carrier-naval-design-bureau.335341/page-7#ixzz3EiZIPVE8

...
That aside, you clearly failed to notice the operant word was NOT as in 'not steampowered'.
...
And so, it is mr. baby to you.

 

[sancho]

As I said, 4.5 gen jets will become quite inferior for the time-period where Vishaal & it's possible sister ships are
supposed to serve. While there is a possibility we might indeed go for Rafale-M (I would count out F/A-18s because
it would make sense both from a technical, cost & logistical perspective to go for Rafale-M, which would share
it's table with IAF Rafales, rather than a new MMRCA), it would at best be seen as an interim solution.

On the contrary, I think the chances for the F18SH are even better than for Rafale Ms, primarily because we are dependent on US approval for catapults, which surely will come with a buy in return option just as the Russians used Mig 29K procurements to give us the carrier. Therefore F35Cs or F18SHs will be the most likely choices if we want catapults and even compared to the Rafale M, the F18SH is the cheaper and therefore better stop gap solution. Capability wise, the upgrade package will be important to put it above the Rafale (CFTs, weapon pod, NG cockpit...), so ruling it out would be the wrong thing to do.

1) Navalised FGFA - It isn't impossible to modify it for CATOBAR.

Technically yes, but realistically it isn't! The changes are simply too big to make such a complete modification, which had no importance in the design stage. We know the Russians will remail with ski-jump take off for their future carriers to use Mig 29Ks and Naval Pak Fas, while they work on EMALS for bigger AWACS aircrafts and UCAVs. So further modifying FGFA beyond the Naval Pak FA only for IN, would be highly costly and by fare not worth the cost. And as I said, we would have to do it on our own, since we can't use western consulting partners to modify FGFA. So if IN wants a naval FGFA, they have to go for STOBAR carriers!

However, if we decide to ditch EMALS and go for an advanced steam catapult (either develop it indigenously
or JV with Russia/France).

Again, too costly! Russia is not going for Steam catapults anymore as explained above, Japan is not going for propper carriers at all and France can't even afford to buy their hoped 2nd carrier, so don't expect a joint development with them either. Only Brazil was a chance to jointly develop a new carrier fighter and carrier, because they are the only country that also wants to go to CATOBAR carriers in future and therefor had a similar requirement, but we missed that chance.

3) Go for the F-35B

The B version is out of question, because it can land only vertically and not use the advantage of arrested landing. So the bring back weight is limited, besides other major limitations it has compared to the C version, which IN actually asked LM for informations.

 

[sancho]

I think Indian Navy opts for maximum indeginisation due to variety of factors like the lack of funds. Navy always have got the less of defence expenditure than the AF and army, forcing it to look internal means. It did take a lotta years , but now thanks to Navy, Indian shipyards can do build quality vessels.
IAF on the other hands always had the funds on standby, in case a domestic varient got unsatisfied response. So it never really got serious in development of indigenous fighters.

They got the least ammount of funds, because they are the least important force for the defence of the country. There are simply not many naval threats for us, while the main threat lies alongside serval 1000Km land borders and protecting them simply requires more effort and therefor more money.
It's also not really true that IN is opting for maximum indigenisation, look at the airfracts with will have a superior number of imported once and the number is only going up with the currently running helicopter tenders. Same goes for subs, or support vessels. Even the number of Russian made Talwar class Frigates is higher than Shivalik class once so far, so maximising indigenisation is clearly an overstatement.
And how does IAF not get serious with indigenous developments? LCA, FGFA, Dhruv, Rudra, LCH, LUH, MTA, Saras, IJT, DRDO AWACS they even waited a long time for HTT40, IAF simply has the burden of a less capable indigenous aero industry to start with and not a lack of support for such developments. IN on the other side has the advantage and still is buying a lot of arms and techs from foreign countries.

 

[narcon]

Light displacement
Light displacement (LDT) is defined as the weight of the ship excluding cargo, fuel, water, ballast, stores, passengers, crew, but with water in boilers to steaming level.

Every ship has a boiler baby...
Steamship or diesel driven, which is very common.
I have yet to see a ship without a boiler.
So your post is pointless on this.
Get yourself conversant with navigation terminology first.
...

That aside, you clearly failed to notice the operant word was NOT as in 'not steampowered'.

What is the use of above anyway?

Just as I would write: Obama had nice Armani suit but not a fig leaf.....
What is a need to write a "fig leaf" word which no one uses nowadays anyway, neither the cavemen of Tora Bora....Lol

"A cretin is one who acts like one"

 

[nvKyleBrown]

All 10 US CVA are steam-powered. Steam is the operative fluid for nuclear reactors. You heat water to make steam, use the steam to drive a turbine. The spinning turbine drives a generator for electricity, which can be used for all ship purposes. Some use electric motors to drive the ship, some have used turbines directly to drive the ship. The steam is also used for ship-board purposes - including the catapults on most CVAs.

It is not the only way though. Many modern ships are gas-turbine powered. Replace the steam turbine with a gas turbine. Similar operation otherwise (but no steam). There are still diesel powered boats too. COGAS (combined cycle GT + steam) have been proposed, but no one has implemented one that I'm aware of. I would guess the size and weight would be prohibitive. COSAG (main power from steam boiler system + GT for "turbo boost") has been done, but that isn't really for efficiency. CODAG (diesel + GT) is similar, liked for the smaller footprint. COSAG and CODAG are about reasonable cruising performance from a baseline system that is supplemented with a GT for peak performance. GT have very small footprints for their power, but are a bit hoggish with the fuel. There are other arrangements but you get the idea. Steam is by no means out-of-date.

BTW, the USS Kitty Hawk was pulled from service in 2009. There was briefly talk of selling it to India, but there were a lot of problems with that deal and it came to nothing. All US CVAs are now Nimitz class, ~100,000 tons. There will be a new class in the next couple years, but they are essentially the same size.

 

[desimorty]

Second nuclear powered aircraft carrier. No doubt India is spending heavily on military.Arms race with china!

Source: INS Vishal might be nuclear-powered aircraft carrier : Naval Design Bureau | Page 7

Not for China, thats what the media, and Indian higher ups want the masses to believe to justify the spending but if you look closely you'll realize whom this is for. What India has currently is more than enough to keep China away for any misadventure with India expecially when India has the geographical advantage.
The 5000 KM ICBM, is too much for China, all you need is 3000 range land launched, but what you see is further development for ICBMs with longer ranges, that can hit Europe and SLBM as well. I Chinese scholar once pointed out that India's nuclear deterrent is not just for China alone.
The supersonic Brahmos/PJ-10, not really needed against the PLAN. Until a couple of years ago there hard kill against cruisemissiles was horrible!
Su-30MKI's, such long ranges are not for patrolling skies over Tibet or China.
The aim of Indian strategic planning after the Soviet Union collapse was to keep the biggest guy in the neighbourhood away from any misadventure. The biggest guy in the block, is the USN.
Even though relations are good for now, common sense dictates that the USA could and has in the past turned on India despite the DEMOCRAZY tag.
China and India don't view much threat from each other as they do from the US. Neither China or India have the capability to obliterate each other with out hte use of nukes. Only the US of A has this capability.
Today both PLAAF/IAF would only last a couple of months against a air war with the US forces.
India downplays the threat it is or could be to the Western hemisphere. A ploy that has been an envy of China.
China may have a disputed bordar with India, but over the decades these 2 countries have not shot across the border and for good reason. The biggest hurdle between India and China today is not just the Himalayas range but mistrust!

 

[Penguin]

Every ship has a boiler baby...
Steamship or diesel driven, which is very common.
I have yet to see a ship without a boiler.
So your post is pointless on this.
Get yourself conversant with navigation terminology first.
...


What is the use of above anyway?

Just as I would write: Obama had nice Armani suit but not a fig leaf.....
What is a need to write a "fig leaf" word which no one uses nowadays anyway, neither the cavemen of Tora Bora....Lol

"A cretin is one who acts like one"

Sorry, I can't help with the chip on your shoulder. Go look for trouble someplace else please.

 

[Penguin]

All 10 US CVA are steam-powered. Steam is the operative fluid for nuclear reactors. You heat water to make steam, use the steam to drive a turbine. The spinning turbine drives a generator for electricity, which can be used for all ship purposes. Some use electric motors to drive the ship, some have used turbines directly to drive the ship. The steam is also used for ship-board purposes - including the catapults on most CVAs.

It is not the only way though. Many modern ships are gas-turbine powered. Replace the steam turbine with a gas turbine. Similar operation otherwise (but no steam). There are still diesel powered boats too. COGAS (combined cycle GT + steam) have been proposed, but no one has implemented one that I'm aware of. I would guess the size and weight would be prohibitive. COSAG (main power from steam boiler system + GT for "turbo boost") has been done, but that isn't really for efficiency. CODAG (diesel + GT) is similar, liked for the smaller footprint. COSAG and CODAG are about reasonable cruising performance from a baseline system that is supplemented with a GT for peak performance. GT have very small footprints for their power, but are a bit hoggish with the fuel. There are other arrangements but you get the idea. Steam is by no means out-of-date.

BTW, the USS Kitty Hawk was pulled from service in 2009. There was briefly talk of selling it to India, but there were a lot of problems with that deal and it came to nothing. All US CVAs are now Nimitz class, ~100,000 tons. There will be a new class in the next couple years, but they are essentially the same size.

The USN referred to its carriers as CV untill the advent of Enterprise. Since then they've used CVN (for good reason, I suppose). Currently, there are no more CV in USN active service.

There never was any consideration on US side of selling Kitty Hawk to India. Post-WW2, the US has only provided 3 wartime light carriers (CVL) to allies (i.e. France: USS Langley > Lafayette in 1951 and Belleau Wood > Bois Belleau in 1953, and Spain: USS Cabot> Dedalo in 1967)

For the winers (who didn't come foreward themselves with any answers to the original question), another definition of light displacement:

Light Displacement
The ship is complete and ready for service in every respect, including permanent ballast (solid and liquid), and liquids in machinery at operating levels but is without officers, crew, their effects, ammunition, or any items of consumable or variable load.

Light Displacement

The Naval Institute Guide to ships and aircraft of the US fleet by Norman Polmar says:

displacement
light: displacement of ship and all machinery, without crew, provisions, fuel, munitions, other consumables, or aircraft.
standard: displacement of ship fully manned and equipped, ready for sea, including all provisions, munitions and aircraft, but without fuels
full load: displacement of ship complete and ready for service in all respects, including all fuels (aviation as well as ship)

As ship classifications it lists:

CV Multipurpose aircraft carrier
CVN Multipurpose aircraft carrier (nuclear propulsion)