Indian Navy Developments & Discussions

Aniruddha Mulay

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While an SSN need not have very powerful reactor France still operates rubis class ssn with just 48 mw reactor. So 83 MW of arihant itself is sufficient for 3000-4000 ton SSN. But in future power requirements might be much higher thanks to more powerful missile / hypersonic / direct energy weapons etc.

Hence one needs as powerful a reactor possible to be on the safe side.
Isn't 190MW at bit too much for what is supposed a 6000t SSN or the IN wants high speed sub similar to the Alfa class which can cruise at 40+ knots underwater.
 

swapcv

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Isn't 190MW at bit too much for what is supposed a 6000t SSN or the IN wants high speed sub similar to the Alfa class which can cruise at 40+ knots underwater.
Depends on what the hotel load of the SSN will be, if the base load of the submarine without considering the propulsion itself is high, then a high power Reactor might come in handy.
 

omaebakabaka

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Depends on what the hotel load of the SSN will be, if the base load of the submarine without considering the propulsion itself is high, then a high power Reactor might come in handy.
That would be like putting a ferrari engine in maruti 800
 

WolfPack86

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INDIAN NAVY ISSUES RFI FOR LEASE OF 24 LIGHT HELICOPTERS
The Indian navy has issued a Request for Information (RFI) for the lease of 24 light helicopters. The move follows initial parleys with a few Indian operators and OEMs starting last November


The RFI seeks responses from helicopter OEMs, authorized leasing firms, third party financiers or government-sponsored agencies for 24 helicopters with ground support equipment, all maintenance support including performance-based logistics, and training of aircrew and maintainers. The lease will be guided by chapter IX of the latest Defence Acquisition Procedure. The period of initial lease is five years, extendable by another five years, with an option to buy back the airframes at residual value.

This is the first time the Indian navy has resorted to leasing helicopters. The acute shortfall in light helicopters, low availability of obsolescent Chetaks (Alouette-IIIB) and a Naval Utility Helicopter (NUH) program meandering inconclusively has likely driven the navy to exercise the “lease’ "option included in the latest DAP.

However, naval sources have highlighted that the lease program has no impact on the NUH and the two are not mutually exclusive.

The RFI calls for twin-engine helicopters under five tons with wheeled undercarriage and blade folding. They must be capable of sustained operations day and night from afloat and ashore, and their roles will include search-and-rescue, casualty evacuation, communication and low intensity maritime operations. The helicopters should have a residual life of 15 years at the start of the lease, with the flying and “O” level maintenance to be performed by the Indian Navy (and the rest by the lessor or OEM partner).

A serviceability of 75 percent is to be ensured at two bases — one each on western and eastern seaboard.

The aircraft will have a minimum flying quantum of 360 hours per year, with a surge capacity of 50 hours per month for two months in a year. The must be capable of embarked operations up to 180 days in a year — 120 days at a stretch, when required, once a year.

The basic specifications match that of a civil offshore-configured light twin, and include weather radar, standard equipment for instrument flight rules in Class D airspace, AIS, rescue hoist, and emergency floats.

Notable additions include an EO/IR payload, third generation night vision goggle-compatible cockpit, the feasibility of integrating a cabin-mounted 7.62mm machine gun, and an underslung capability of 900 kilograms.

The contours of the RFI clearly indicate a helicopter that can operate “integral” to a warship — an interesting difference from the recently supplied HAL-manufactured Dhruv MK-3 Maritime Role helicopters for coastal security.

As opposed to civil offshore helicopters, naval operations require helicopters to embark ships for extended durations where only frontline servicing or “O” level maintenance activity is possible. For example, Indian navy ships with embarked helicopters routinely carry out extended “Patrol off Gulf” and Overseas Deployment.

The lease modalities and costing by the lessor would have to take into account deeper levels of servicing and maintenance, including, as specified in the RFI, “breakdown at any place in India.” This may throw up exigencies that are outside the ambit of “O” level if the helicopter breaks down or becomes “AOG” in the middle of the sea. Delivering 75 percent serviceability in situations outside the reach of the lessor/OEM will pose special challenges.

The RFI seeks responses by June 18, and this will be followed by an Approval of Necessity (AoN) within six months and award of contract within stipulated timelines under DAP.

About seven established OEMs and non-scheduled operators from India and abroad are believed to have evinced interest in the lease.
 

swapcv

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That would be like putting a ferrari engine in maruti 800
Nope, for a 6000ton Submarine featuring high base/hotel load, 190MW Reactor is pretty standard, the larger Akula itself uses a 190MW OK-650 reactor which powers a 32MW Steam turbine and Two 2MW Turbogenerators, Virginia's S9G Reactor are rated at 210MW driving a 30MW pumpjet, Astutes are a bit smaller and hence have a smaller reactor PWR-2 Core H with 145MW output powering a 20MW Turbine. The point is there is a difference between the reactor output and the Turbine output with the latter being itself a subset of the former. All Reactors are rated for the Thermal Output not the Turbines which they power.
 

Lonewolf

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Nope, for a 6000ton Submarine featuring high base/hotel load, 190MW Reactor is pretty standard, the larger Akula itself uses a 190MW OK-650 reactor which powers a 32MW Steam turbine and Two 2MW Turbogenerators, Virginia's S9G Reactor are rated at 210MW driving a 30MW pumpjet, Astutes are a bit smaller and hence have a smaller reactor PWR-2 Core H with 145MW output powering a 20MW Turbine. The point is there is a difference between the reactor output and the Turbine output with the latter being itself a subset of the former. All Reactors are rated for the Thermal Output not the Turbines which they power.
Can't we use a electric motor powered by nuclear reactor electricity ?
 

swapcv

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Can't we use a electric motor powered by nuclear reactor electricity ?
Naval Group's presentation to our babus and top brass in the MOD and Navy was probably just for that reason, it might be a way for them to get into our P-75A project by pitching their K-15 Reactor. Rated at 150MW, it is unique amongst new reactors in that instead of a steam turbine driving a conventional shaft, it generates electricity to drive an electric motor which powers the pumpjet. In a way it makes the Barracuda's a hybrid of a Nuclear Sub and a Diesel Electric sub with AIP.
 

omaebakabaka

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Can't we use a electric motor powered by nuclear reactor electricity ?
Delta 4 class with about 11k tons is powered by two reactors at 190MW and isn't that more or less tonnage for this class of reactor? There seems to be certain optimal parameters like speed and few other things that will limit the peak draw, I think most subs are at 44 to 40 kph to fit into optimal sound profile even then they normal stick around 30 plus? Special ones do dive deep and go fast as high as 60 to 70...
Not sure params are that different for SSBN vs SSN in terms of reactors, don't think so but I am not sure
Looks like standardization of reactors across wide range of ships requiring different power requirements rather than tonnage based on past classes and current?
 
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Gessler

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Naval Group's presentation to our babus and top brass in the MOD and Navy was probably just for that reason, it might be a way for them to get into our P-75A project by pitching their K-15 Reactor. Rated at 150MW, it is unique amongst new reactors in that instead of a steam turbine driving a conventional shaft, it generates electricity to drive an electric motor which powers the pumpjet. In a way it makes the Barracuda's a hybrid of a Nuclear Sub and a Diesel Electric sub with AIP.
I doubt we are interested in an LEU reactor. Only reason French went with that is for sake of maximum commonality with civilian reactors, thereby saving up-front costs. However this will prove more costly to maintain (and less efficient at keeping operational readiness high) in the long run.

Far as I know, Arihant's 83MWt HEU PWR itself is not where IN would like it to be with regard to refuel cycle frequency. Going with LEU would make this worse. HEU with significantly higher enrichment than Arihant's CLWR-B1 is the way to go. There's a reason why most nuclear Navies use HEU.

The French can offer what they like however I'd think the areas where we'd be interested in their cooperation would chiefly be:
  • Sonar technology
  • Electronics, mainly Photonics masts & new ESM gear (Thales)
  • Pumpjet propulsion
...and not Reactor.
 

WolfPack86

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NAVY SEEKS AMENDMENT TO 30-YEAR SUBMARINE PLAN, WANTS SIX NUCLEAR BOATS
In the backdrop of rapidly expanding Chinese Navy, the Indian Navy wants six SSNs to replace diesel powered conventional attack submarines as Indo-Pacific has emerged as the new theatre.

The Indian Navy has approached the Narendra Modi government for approval to make changes in the Cabinet Committee of Security (CCS) approved 30-year submarine building plan by replacing six conventional attack vessels with nuclear powered platforms in the context of changing strategic scenario in Indo-Pacific.

The 30-year submarine plan was approved by Atal Bihari Vajpayee government in July 1999 for induction of 24 diesel attack submarines. As of now, the Indian Navy has 12 ageing conventional attack submarines plus three new Kalvari class submarines, first of which was commissioned in December 2017 as part of the ₹23,652 crore project approved way back in 2005.

It is understood that the navy has sought the Cabinet approval to allow it new submarine force levels of 18 conventional diesel attack submarines including those with air independent propulsion and six nuclear attack submarines or SSNs. This change has been sought keeping in mind the rapid increase of nuclear submarine arsenal by People’s Liberation Army Navy (PLAN) and to protect the Indo-Pacific from future domination by the adversary.

As of now, the India has one Akula class submarine INS Chakra on lease from Russian Federation and one ballistic missile firing submarine INS Arighat. The two are under the Strategic Forces Command. All the ballistic missile firing submarines also called SSBNs are outside the purview of Indian Navy and with Strategic Forces Command.

According to national security planners, once the Modi government approves the changes to the 30-year-old plan, the Indian Navy will move the Defence Ministry for acceptance of necessity (AON) before inviting request for proposals from the key allies for joint development and building of the six nuclear powered submarines under the Atmanirbhar Bharat route. The project will take a minimum of 10 years to complete as per Indian Navy estimates.

While the Indian Navy wanted six more AIP equipped diesel submarines to be added to complete the 30 year submarine force levels, the national security planners convinced the Admirals that nuclear attack submarine is a much more potent platform with the capacity to stay below surface for months and only surface for crew change and logistics. The equatorial waters of Indian Ocean make submarines a very potent weapon due to temperature differences on surface and below water. This causes total internal reflection due to changes in medium and makes submarines in equatorial waters the most difficult to detect. It is due to this phenomenon that the SSNs will act as a deterrent for both sea access and sea denial to the adversary.

With the Defence Research and Development Organization (DRDO) being able to indigenously develop the AIP technology, all the INS Kalvari class submarines will be retrofitted with the new technology during upgrades or mid-life refits. The Indian Navy too will be taking an orbital jump by moving from diesel submarines to nuclear powered and conventional cruise missile equipped platforms.
 

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