Project-75I class SSK Submarines

[BON PLAN]

However the point remains that price paid of AIP equipped subs is comparable to an SSN

? I'm not sure.

There is no actually built SSN in the same weight class than medium SSK AIP .

The Rubis french SSN, one of the smaller one, is no more produce and the new nuclear and confort rules (and weapons range : cruise missile) require a bigger design (>4000 T instead of 2700), so it's not easy to compare a 4000T SSN and a 2000T SSK AIP.
And the price also.

 

[sthf]

@BON PLAN Didn't France offer a conventional sub with Barracuda hull to Aussies?

 

[BON PLAN]

@BON PLAN Didn't France offer a conventional sub with Barracuda hull to Aussies?

Yes.
Barracuda Short fin is a classical 4000+ tons sub, based on Barracuda french SSN hull. without AIP !

 

[tharun]

Does any one know the requirements for P-75I.
How much power is required in both scenario to stay under water for 30+ days without moving and with a constant 4-7 knots speed?

 

[tharun]

Here is A26 submarine with tomahawk cruise missiles in vertical launch system total 18 in numbers constructed by SAAB.

 

[pmaitra]

Here is A26 submarine with tomahawk cruise missiles in vertical launch system total 18 in numbers constructed by SAAB.

Has it been constructed, or is it just a proposal?

 

[Armand2REP]

Yes.
Barracuda Short fin is a classical 4000+ tons sub, based on Barracuda french SSN hull. without AIP !

AIP is rather obsolete with the advent of next gen Li Ion cells.

 

[tharun]

Has it been constructed, or is it just a proposal?

At present it is proposal for both sweden and export.
A26 is being in developed and in final stages to construct and deliver by 2022 to swedish navy.
And the whole section is 10 meters long and 500 tons in weight with 18 tomahawk missiles 6 in each tube.

 

[tharun]

AIP is rather obsolete with the advent of next gen Li Ion cells.

But still it is in development stage.
If you had a AIP with hydrogen and oxygen it can be filled at sea with in a couple of hours,but it takes lot of time to recharge batteries.

 

[Armand2REP]

But still it is in development stage.
If you had a AIP with hydrogen and oxygen it can be filled at sea with in a couple of hours,but it takes lot of time to recharge batteries.

Current AIP SSKs run on inefficient Lead Acid batteries. Even using current commercial Li Ion technology you get 4X the capacity and even faster recharge speeds. Using the next gen batteries doubles all of that, AIP is just a waste of space at that point.

 

[Bahamut]

Current AIP SSKs run on inefficient Lead Acid batteries. Even using current commercial Li Ion technology you get 4X the capacity and even faster recharge speeds. Using the next gen batteries doubles all of that, AIP is just a waste of space at that point.

Yes but Li have some storage problems as these prone to fire and explosion

 

[Armand2REP]

Yes but Li have some storage problems as these prone to fire and explosion

Li Ion batteries are already scheduled for mutiple SSK classes across the globe. It is the future now.

 

[tharun]

Current AIP SSKs run on inefficient Lead Acid batteries. Even using current commercial Li Ion technology you get 4X the capacity and even faster recharge speeds. Using the next gen batteries doubles all of that, AIP is just a waste of space at that point.

Japanese navy's soryu submarine carries AIP fuel which is equivalent to 100MW. At present there is no submarine that can carry half that capacity in battery even it is Li-ion.

 

[Filtercoffee]

Here is a start for never ending 'GOD' power through graphite silicon crystal sandwiched battery cells available today.
https://youtu.be/F6LdcLfYBGg

 

[Armand2REP]

Japanese navy's soryu submarine carries AIP fuel which is equivalent to 100MW. At present there is no submarine that can carry half that capacity in battery even it is Li-ion.

There is no Li Ion sub as of yet to compare it to. That capacity doesn't matter when you need speed. A sub running AIP doesn't even increase it's battery level if running 3-4knts. You want more battery capacity to sustain high tempo operations. Most SSNs don't stay submerged more than 2-3 weeks, what does an SSK need with that?

 

[Prashant12]

P75(I) submarine to be first deal under ‘Strategic Partnership’

Defence Ministry likely to issue the EoI for the project later this week

New Delhi, June 8:
The long-pending ₹60,000-crore P75(I) submarine programme will be the first big-ticket defence deal to be announced under the ‘Strategic Partnership’ (SP) policy rolled out last month.

Two partners
The Defence Ministry is likely to issue the expression of interest (EoI) for the project later this week. Under this, Larsen and Toubro and Reliance Defence will be registered as the only two strategic partners under the new policy. L&T and Reliance Defence are the only two shipyards eligible to participate in programme, sources told BusinessLine.

The government will also shortlist the foreign original equipment manufacturers (OEMs) for the programme based on their plans for transfer of technology and requirements of the Navy. Following this, the request for proposal (RFP) will be issued which will also enlist the shortlisted OEMs, said sources.

The SPs will then select the OEMs out of the shortlisted ones and submit their respective bids accordingly. The lowest bidder will be selected as the SP for submarines, sources added.

The P75(I) or ‘Project 75 India’ is a follow-on programme of the Indian Navy to the already undergoing construction of six Scorpene class diesel-electric submarines that are being built at the Mazagon Dock Ltd through technology transfer from France’s DCNS.

The P75(I) was announced in October 2014. The submarines to be built under this programme will be technologically more enhanced than the ones that are nearing completion under P75.

India has plans to build a fleet of 24 submarines for the navy.

Under P75(I), the submarines will have Air Independent Propulsion (AIP), under which these can stay longer inside water. Besides, it will also have a vertical launch system that will enable these submarines to have multiple Brahmos supersonic cruise missiles for land attack. Additionally, a brand new cruise missile will be fitted as the main anti-ship missile.

Guaranteed orders
The SP policy was approved by Cabinet on May 24 under which private sector defence companies will get guaranteed orders under each platform, such as submarines, fighter jets, helicopters and armoured vehicles. The private firms will then be allowed to partner with foreign firms which will then be placed defence deals worth billions of dollars.

http://www.thehindubusinessline.com...nder-strategic-partnership/article9723040.ece

 

[tharun]

There is no Li Ion sub as of yet to compare it to.

I agree that there is submarine with Li-ion to compare.

That capacity doesn't matter when you need speed

How? Siemens motor for submarine is rated at 6mw at full speed.If max speed is 20 knots if you need to escape to longer distances you need large battery capacity.

A sub running AIP doesn't even increase it's battery level if running 3-4knts.

AIP is used mostly for running hotel power(submarines energy load) and move at constant speed of 3-4 knots. Batteries are recharged if sub is stationary. Mostly batteries are used for quick speed for escape or attack.

Most SSNs don't stay submerged more than 2-3 weeks, what does an SSK need with that?

In times of worst situation they need to stay more than expected.A submarines to home port only when a replacement submarine comes to takes it's place.

 

[WolfPack86]

EXPRESSION OF INTEREST FOR RS 60,000 CR P-75I SUBMARINE PROGRAM LIKELY THIS WEEK
According to sources, the MoD soon after the approval of the SP Model started seeking financial details of the companies which are going to get the EoI for the P 75i

The Ministry of Defence is likely to issue expression of interest (EoI) for Rs 60,000-crore P-75i submarine program for the Indian Navy this week. This is the first major program to be launched by the MoD under the strategic partnership model that was approved by the Cabinet Committee on Security on June 2. As reported by FE earlier, Larsen & Toubro’s (L&T’s) Katupalli yard and Reliance Defence & Offshore Engineering Company are the only two shipyards eligible to participate in the P-75 i Program. Explaining the process, a senior officer said, “The MoD has set a very aggressive time line for this project.

The plan is to complete the process of selection for the Indian strategic partner, and also to complete the process for the selection of the OEMs, so that in October the request for proposal (RfP) is issued. The plan is to get the long delayed P-75i program on track by March 2018.” According to sources, the MoD soon after the approval of the SP Model started seeking financial details of the companies which are going to get the EoI for the P 75i.

The OEMs that are expected to get the EoI include DCNS of France, SAAB of Sweden, Rosoboronexport State Corporation of Russia and German ThyssenKrupp Marine Systems. A high level committee headed by a senior Navy officer was designated to inspect both public and private shipyards to shortlist candidates to issue the RfP for the project (designated P-75i).

In its final presentation to the MoD, the committee down selected two private sector shipyards for building six conventional submarines– L&T and Pipavav Defence. This will be a ‘Buy and Make (India)’ tender, with an Indian shipyard taking the lead in responding to the tender. The committee with representatives from the Navy and the MoD conducted a survey of shipyards along both coasts including Garden Reach Shipbuilders, Hindustan Shipyard, Goa Shipyard, L&T, Mazgaon Docks, ABG Shipyard and Pipavav Shipyard.

According to the government’s decision, all six submarines will be built in India on the lines of the predecessor P75 `Scorpene’ production line at Mazgaon Dock (MDL), Mumbai. Bids will be invited from Indian shipyards to build the six submarines using transferred technology from a foreign partner.

Due to long delays in the `Scorpene’ (project 75) at Mazgaon Dock Limited (Mumbai) which was intended to induct the vessels at the rate on one ship per year since 2012 has left the Submarine force well below requisite levels. Also, previously planned induction of five midget submarines, combined with the fresh impetus on the strategic submarine program constitute a work-load that is far beyond the capacity of existing public sector shipyards.

According to the Indian Navy, the new submarines will differ from the earlier lot since the qualitative requirements have been altered. The six new submarines in P-75i project will outline various critical parameters including the weight and design of the submarine. These submarines are expected to be bigger than the 1800-ton `Scorpene’ class being built for P-75 project.
http://www.indiandefensenews.in/2017/06/expression-of-interest-for-rs-60000-cr.html

 

[Armand2REP]

I agree that there is submarine with Li-ion to compare.

How? Siemens motor for submarine is rated at 6mw at full speed.If max speed is 20 knots if you need to escape to longer distances you need large battery capacity.

AIP is used mostly for running hotel power(submarines energy load) and move at constant speed of 3-4 knots. Batteries are recharged if sub is stationary. Mostly batteries are used for quick speed for escape or attack.

In times of worst situation they need to stay more than expected.A submarines to home port only when a replacement submarine comes to takes it's place.

When a Li Ion battery capacity can match an AIP recharging a Lead Acid battery 4X it is pretty obvious which is the better option. AIP would take over a day to recharge a stationary submarine that also requires water flow to disperse its waste products and also puts it at risk if detected. Batteries are used all of the time, the power generated from AIP is only charging the battery. If required to dash on lead acid batteries the power would drain too quickly to make a second break attempt or traverse a great distance at speed. SSNs and especially not SSKs are going to be submerged for an entire patrol, they do not have the amenities of an SSBN which is required to stay under that long. An SSK is very small, it would drive the crew insane to spend weeks with no fresh food and no ability to stretch the legs.

 

[tharun]

When a Li Ion battery capacity can match an AIP recharging a Lead Acid battery 4X it is pretty obvious which is the better option. AIP would take over a day to recharge a stationary submarine that also requires water flow to disperse its waste products and also puts it at risk if detected. Batteries are used all of the time, the power generated from AIP is only charging the battery. If required to dash on lead acid batteries the power would drain too quickly to make a second break attempt or traverse a great distance at speed. SSNs and especially not SSKs are going to be submerged for an entire patrol, they do not have the amenities of an SSBN which is required to stay under that long. An SSK is very small, it would drive the crew insane to spend weeks with no fresh food and no ability to stretch the legs.

AIP in submarine is used for two things,
1)When it is stationary it will be used to recharge batteries.
2)When in transit with 3-4 knots mostly aip is used because of two reasons battery lifecycle and always keep the batteries full.