'The P-17 Frigates, heralds a paradigm shift in the design'

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Interview with Rear Admiral KN Vaidyanathan, Director General Naval Design​

Shivalik, the first of class of the P-17 frigates, heralds a paradigm shift in the design of future surface combatants for the Indian navy. While the sleek and stealthy appearance of Shivalik, sets her as a class apart from earlier indigenous designs, the ship embodies several new design features to give her much improved operational capabilities. “Stealth” has been a major thrust area from the early stages of the design. Apart from this, the design embodies several new concepts for improved survivability, seakeeping, ship handling and on-board habitability.

The watertight subdivision of the hull meets the most stringent damaged stability requirements and the distributed power supply systems using Energy Distribution Centres (EDCs) has allowed zoning in the Power Generation & Distribution (PGD). The incorporation of the TACS (Total Atmosphere Control System) for the ship’s air conditioning and ventilation system, which features considerably reduced number of external air induction/exhaust terminals, gives her a very user friendly citadel which is easy to operate and maintain. This gives the additional benefit of uncluttered exteriors of the ship which has significantly reduced the Radar Cross section (RCS) of Shivalik.

The hull form with carefully crafted hull sections and load water plane, gives the vessel excellent sea keeping qualities together with very good propulsion performance as a result of low shaft rake and very low appendages resistance. The relatively large rudders give the ship excellent manoeuvring performance as has been borne out by the ship trials. Use of modular accommodation has considerably improved on board habitability.

The design of Shivalik evolved with considerable focus on reducing the ship signatures. Primary focus was on reducing the RCS, Infrared signatures and the Radiated underwater noise of the ship.

RCS: The hull form features flared main hull and sloped full beam superstructure to considerably reduce specular reflections. Special care was taken to avoid dihedral and trihedral corners which cause multiple radar scattering. The boat deck has been concealed behind radar suppression screens. The Gun turret in the foxle has a stealth canopy and the flush deck Vertical Launch Missile (VLMs) for the Surface to Surface Missiles (SSMs) have been conducive to reduced RCS.

The helo hangar has sloped shutters and flush deck rails for helo traversing gear. The hull form and superstructure was evolved iteratively by extensive 3D CAD modelling and continuous RCS signature evaluation using specialist signature evaluation software.

IR Signature Reduction: The infrared signature reduction is achieved by using Eductor Diffuser IR suppression devices for the Gas turbine and the diesel engines. Besides exhaust gas cooling, hot metal cooling is achieved to afford good look-down protection from hostile IR sensors. The engine room ventilation with sea water coolers and acoustic enclosures for DAs help to reduce hull contrast temperatures.

Radiated noise: Acoustic studies were undertaken from early design stages by modelling the structure and airborne noise characteristics of machinery equipment to predict the underwater radiated noise. The results of these studies helped drive a balanced approach to noise reduction guiding the selection of machinery configuration and mounting arrangements with specifications for the structure borne vibrations and air borne noise which were included in the procurement orders of the equipment. Acoustic signatures were verified during factory acceptance trials, before clearing the noise critical machinery for installation onboard ship. The sea water suctions are arranged from carefully designed sea chests, to avoid radiation of fluid borne noises due to pump impulses.

Procuring machinery and equipment meeting the stringent vibration and airborne noise specifications was quite a challenge. However, I must say, the Indian industry has come some way to meet the requirements, but there is much road ahead to cover.

What are the major new systems in the Shivalik class? What are the new features in terms of the layouts on the ship?

Shivalik is the first IN ship to have a Combined Diesel or Gas Turbine (CODOG) propulsion plant. This propulsion configuration combines the compact high power/speed benefits of the gas turbines with the long endurance advantage of the diesel propulsion.

The twin shaft arrangement features relatively large, slow running propellers which, while driving the ship efficiently at the top speed, also have high cavitation inception speeds compared with earlier designs. This feature of the propeller compliments the low noise features of the machinery to provide silent speed regimes of operation up to cruise speeds. The Integrated Machinery Control System (IMCS) features multifunction displays with distributed Remote Terminal Units (RTUs) riding on a dual redundant Gigabit Ethernet data bus to monitor and control the ship’s propulsion and auxiliary systems including the Battle Damage Control System (BDCS).

The Automated Power Management System (APMS) manages the generation and distribution of electric power in the ship. The ship has an ATM based Integrated Ship Data Network (AISDN) which serves as the backbone on which the external and internal communication systems, data communication between weapons and indigenous sensors and navigation data distribution are supported.

The Integrated Versatile Console System (IVCS) replaces the earlier plug in systems providing multifunction display with touch screens for displaying all navigation data and status of weapons and sensors. The IVCS also supports the internal communication of the ship. The Combat management system, with fleet functionality, is a sophisticated development with considerable participation of the navy which will effectively co-ordinate the functions of the several weapons and sensors not only on board the ship but also those of other ships in company.

The P17 packs all the punch of a destroyer in her design.

The layout features wide alleyways and uncluttered upper decks. A centre line passage between the two helicopter hangars provides a clear lobby between the helo deck and the inside of the ship. The flush deck rails of the helo traversing system, besides being conducive to lower RCS, gives the ship much improved operational flexibility for the helicopter. The large bridge with generously provided bridge wings is ergonomically designed. The large windows of the bridge give very good all round visibility and the diverse equipment on the bridge are neatly packed into consoles for good aesthetics.

How has Shivalik performed in the sea trials? What are the highlights of the signature reductions realised on Shivalik?

Shivalik has undergone extensive sea trials for proving her machinery and ship handling. The sea trials have been very satisfactory and the ship handling has been seen to be very good. The ship sails rock steady even at her top speed. The hull is vibration free and the machinery reasonably quiet.

How does the design of Shivalik compare with other designs of her class? With the experience of Shivalik, what would be the direction for the design of the follow on class P-17A?

Shivalik design embodies many firsts in IN ships. The CODOG propulsion plant, the Ship Data network (AISDN), the new Total Atmosphere Control System (TACS) for the ship’s air-conditioning and ventilation, IMCS, APMS, the distributed PGD system using EDCs, the IVCS, etc., set her quite apart from earlier designs in terms of design concepts, automation and operational advantages. The ship compares very well with contemporary world designs in terms of capabilities packed into a class of ship of her size. The design and construction of Shivalik have produced a wealth of experience on which to further improve the P17A design. P17A will be more stealthy with covered mooring deck and flush deck mounted (VLM) weapon systems. The number of antennae on the ship will be reduced by use of a multifunction radar. The design will also explore better options for roll stabilization of the platform. In order to help cut down build periods and improve productivity, it is planned to go in for modular integrated construction for P17A. The design, project management and life cycle will be supported by a more comprehensive CAD/PLM.

How have the other new design projects benefited from the design experience of Shivalik?

Continuous design engagements of the Design organization is vital for the enhancement of design skills and nurturing of design capabilities. After the design of the P-15 class, there was some lull period when no new ship projects were sanctioned. However with the commencement of P 17 in the mid nineties, there was a resurrection of the design capabilities of DGND and the somewhat dormant skill sets got rejuvenated. P 17 is truly a watershed in the design history of the navy in terms of adopting new design concepts and new strategy for the design projects. This has set a definite course for managing and progressing the designs of P15 A destroyers, P 28 corvettes and P 71 Indigenous Aircraft carrier.

What are the challenges faced by the Navy for the new design projects? Is the Navy able to attract quality manpower for specialized tasks like warship design? To what extent, the now available IT tools, have changed the paradigm of design processes?

There are several new challenges faced by the Navy for the new design projects. To meet the genuine new aspirations of the naval staff in terms of required platform capabilities, there is considerable pressure on new indigenous equipment suppliers to meet the more stringent noise and vibration specifications given by the designers. It is a challenging task for the project managers to drive the indigenous suppliers to meet specified standards. It is a recognized fact the world over, that any warship design is an evolutionary process, particularly in an environment of developing industry such as ours. Given this fact, it is very challenging to meet the cost and time budgets for equipment development which in turn impact the ship construction programme. The task of balancing the conflicting requirements of incorporating the latest available technologies whilst freezing specification at a finite time, poses special challenges in a country like ours.

This is so as we are still maturing on many technology areas and would yet like to maintain high indigenous content. Manpower for the specialist tasks of design is another challenge faced by the Navy. However even today, the Navy is the only repository of the large pool of skilled and experienced warship designers. Naval officers, going through the grill of elaborate training in the Navy with wide job profiles relevant to preparing them as designers, still continue to be the most promising feeder source for the naval design organization. With available IT tools, there has been a paradigm shift in design processes. The availability of a suite of initial design software allows a wider exploration for optimizing design.

This has consequently made the process more officer-centric. The wide area network (WAN) connectivity with the shipyards has facilitated easier and faster exchange of design drawings,data and documents with the shipyard. The availability of CAD modelling software with good integration of a Product Data Manager (PDM) will provide a robust platform for optimizing design layouts and maintaining good configuration control in design. The PDM will help capture all relevant data and linked information arranged in an organized product structure. In the near future, the available IT design tools will help progressing designs in a multi-user environment through enterprise wide efforts with collaboration of platform designers, shipbuilders, equipment suppliers and system developers.

What is the Navy expecting from the Indian Industry for the future naval platforms?

The Navy, with several new ship projects on the anvil, is looking for considerable support from the Indian industry to successfully realize the naval ship projects. The industry is urged to invest efforts to develop naval equipment meeting the stringent standards, particularly for noise and vibration, as these are crucial to meeting the performance requirements of the ship. Modularity of systems, with standard well-defined minimum interfaces with the ship will be the thrust for the future. This will help the ship design and construction to proceed on the basis of the agreed interfaces while the equipment supplier can concurrently develop equipment within the confines of the module.

Such an approach will also, to a large extent, accommodate evolutionary designs of state of the art equipment to meet the rising aspirations of the naval staff. P 17 is truly a watershed in the design history of the navy in terms of adopting new design concepts and new strategy for the design projects. This has set a definite course for managing and progressing the designs of P15 A destroyers, P 28 corvettes and P 71 Indigenous Aircraft carrier. This will give confidence to both parties for sharing the risks of development as well share the benefits of new technology with reduced costs.

'The P-17 Frigates, heralds a paradigm shift in the design'

 

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Have a Better Article on P17. Will Post after Dinner.

 

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Have a Better Article on P17. Will Post after Dinner.

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Here You Go. A Couple of Them. Something's Very New for me.


India added new fire power and muscle to its Navy when Defence Minister A K Antony formally launched INS 'Shivalik' -- the S-class Frigate -- at the Mazagon Dock on Thursday. The Shivalik is a multirole stealth ship incorporating advanced signature suppression and signature management features along with both air defence and anti-sub marine capabilities.

India added new fire power and muscle to its Navy when Defence Minister A K Antony formally launched INS 'Shivalik' -- the S-class Frigate -- at the Mazagon Dock on Thursday. The Shivalik is a multirole stealth ship incorporating advanced signature suppression and signature management features along with both air defence and anti-sub marine capabilities.

The 6200-kg INS Shivalik is the first indigenous stealth frigate that will join the Navy and will provide the sea wing the capability to launch surprise attacks on enemy target from very close range than other warships. Satellites can give inputs to the frigate on lurking enemy vessels and Shivalik can creep as close as possible to the target without being detected. It can then fire and scoot.

In fact, during sea trials, Indian battleships that tried trailing Shivalik could not detect it on their radar within a radius of 100 km. Shivalik is one of the heaviest frigates in the world. Powering the ship is the LM 2500 Gas Turbine engines that can give it an enviable top speed in excess of 30 knots, enabling it to shoot and scoot at an impressive rate. The option to switch over the diesel engines gives the warship an endurance of over 9,000 km and it can sail non-stop without refueling for a month.

Shivalik will carry surface-to-surface Klub missile, surface-to-air Shtil and point defence Barak missile system. Though it does not torpedoes it has Sea King attack helicopters that can launch anti-submarine warfare. Shivalik is designed in such a way that it has reduced radar reflections, changed geometry of structures on top, very few projections on the upper deck that is normally a giveaway for other fighter ships, muffled noise vibration as well as lower magnetic and heat signatures.

Measuring 142.5 mt from bow to stern, Shivalik has a range of about 5,000 nautical miles at a cruising speed of 18 knots. On board manning the frigate would be 257 naval men, which includes 35 officers and 222 sailors. It can be at sea for almost a month without touching a port or mid-sea refuelling.

On major plus pointis that Shivalik can operate in a nuclear, biological, chemical weapons (NBC) environment. Its air filters do not allow any outside air to come inside in a NBC zone. "The Shivalik class will be the navy's mainstay frigate in the first half of 21 century. It is capable of operating in multi-threat environment," said Navy chief Admiral Nirmal Verma.

According to Mazgaon Dock Ltd (MDL) Chairman and Managing Director, Vice Admiral (Retd) HS Malhi: "Nowhere in the world ship of this size has been incorporated with stealth features. It is a 6000 tonne ship and is the largest stealth frigate in the world." It was MDL that built INS Shivalik.

Two more ships of the same class, INS Satpura and INS Sahayadri, are under constructions. The first one is expected to be launched by the end of this year, and the other in 2011, said Malhi.

Following the success of Shivalik, the defence acquisition council has recently approved constructions of seven more similar ships, which will be manufactured by the MDL and Garden Reach Shipbuilders and Engineers (GRSE), Kolkata. Four will be manufactured at MDL and three at GRSE. Though the ship is not completely invisible, it would be hard to detect on the high seas.

Armed with surface-to-surface and surface-to-air missiles, Shivalik carries two advanced helicopters and is equipped with state-of-the-art CODOG (Combined Diesel or Gas Turbine) propulsion system along with most of comprehensive innovative features.

Shivalik marks another move in securing India's sea lanes, according to Mazagon Docks, which built the ship. Essentially, the stealth ships hoodwink the radars. Though not completely foolproof, the Swedish Navy currently has what is believed to be the most "invisible" ship yet. Reports also indicate that the Royal Navy of the UK and the US Navy are actively involved in developing futuristic ships that are almost invisible in the high seas.

Already advanced countries have "stealth" aircraft. The first one was the F117; then came the B-2 bomber, in the 1980s. Visually: Earlier this was done by high flying aircraft, but the task has been taken over by sensitive satellites. A major problem has been darkness and cloud cover. This is why nations move their advanced ships loaded with firepower during moonless nights or under thick cloud cover. The US did this during the Iraq war.

Radar: Ever since it was invented in the 1940s, radars are now the mainstay in detecting invading aircraft and ships. The new move is to reduce the `signatures' sent out to the bare minimum so that the radar cannot catch any blips. The Shivalik has advanced signature suppression and signature management features.

Sonar: Here sound waves are used to detect submarines. But to hoodwink sonars, submarines used to `sleep' on the ocean floor and remain motionless for a long time. Hence, sonar readers used to think that the piece they found on their sound map was probably a rock. But this was overcome soon by developing advanced sonar systems that caught the burr of engines. Now some navies have ultra silent engines and special paint which can deflect the sound waves.

Infra-red: This technology is used by missiles that have a `nose' for heat. These missiles hone in on systems that generate heat and was used effectively to track enemy ships. But the new vessels have special `heat masks' the cut off the heat signatures.

The world leader in stealth technology is Sweden with the Visby corvette class built by shipbuilders Kockums at Karlskrona yard.

Visby's entire body is made of carbon fibre - commonly used in the making of the chassis of Formula One cars and the sleek hulls of high-powered racing yachts. This makes Visby very light than ships that use steel. It also has a special angular design to deflect and fool the radar signature. By this, the ship could get within 30km of the enemy before being spotted. By then it could have used its deadly fire power. If the stealth ship with special angular design gets caught, the radar output will only see is as a small ship or a boat, not as a warship.

The US has upgraded its stealth technology in the DD(X) destroyer, due to be commissioned this year. The DD(X) is expected to cost less and will be able to fire large volumes of surface fire at very close range. UK's Royal Navy, it too will have a new breed of stealth ships in action soon. HMS Daring, the first of the Type 45 destroyers, is being constructed at BAE Systems' Govan and Scotstoun yards in Glasgow. is due to enter service in 2007.

What needs to be flagged here is that despite advanced technology, ships can never be 100 percent invisible. Submarines, yes. Many modern submarines are very hard to detect, but that will not be the case with surface ships.

There is also one danger. Many of the new vessels are controlled by state-of-the-art computer systems using the latest operating windows. Now these could be sitting ducks for hackers. Though the operating systems are guarded by firewalls, it would be a hacker's `delight' to get through the wall. Hacking could put a ship in danger and the operators would have to fall back to traditional steering and navigation in such an eventuality.

India's stealth frigates have been under construction under Project 17 class by Mazagon Dock Limited (MDL) in Mumbai since December 2000. All the ships are named after famous mountain ranges of the Indian sub-continent.

It was in June 2009 that India's political Defence Acquisition Council (DAC) cleared India's largest ever indigenous defence contract: about Rs 45,000 crore to manufacture seven Project 17A frigates. The DAC reportedly made one major change at that time by insisting that all seven warships must be manufactured in India by the Mazagon Dock Ltd. in Mumbai (MDL), and by Garden Reach Shipbuilders and Engineers (GRSE) in Kolkata. Work was then divided between the two shipyards, making P17A India's first dual-shipyard contract.

Earlier, the project ran into some rough weather with the Indian Navy insisting that the first two ships be built in a European shipyard, even if it doubles those ships' bid cost. Why? Because these ships will use modular construction based on 300-tonne "blocks" that are fully equipped, and must fit together so precisely that pipes, wiring, and other components all align. Neither Mazagon Dock Limited (MDL) in Mumbai, nor Garden Reach Shipbuilders and Engineers (GRSE) in Kolkata, has ever used this method. The Navy preferred to have their workers learn by working at a shipyard with experience in this approach, before bringing the skills back to India.

But GRSE Chairman and Managing Director Rear Admiral KC Sekhar was quoted in the media as saying that GRSE will have a fully equipped modular yard with a 250-ton Goliath crane by mid-2011.

ANI adds: Shivalik has been built at Mumbai's Mazagaon Docks Ltd as a part of the Indian Navy's Project 17. The Navy will get as many as ten more stealth warships in next 9-10 years.

The hard to detect warships will form a crucial component of the Indian Navy. It is equipped with a mix of Indian, Russian, Israeli and Western weapons and sensors. A 250-member crew including 35 officers will man INS Shivalik.

The new design features give the ship enhanced operational capabilities in terms of survivability, stealth, sea keeping, ship handling and weapons. The Shivalik-class vessels are being built entirely in India and have Klub anti-ship missiles, Shtil surface-to-air missiles, Barak air and missile defence systems and RBU 6000 anti-submarine warfare rockets.

Shivalik is also equipped with state-of-the-art defence against nuclear, biological and chemical attacks. "The Atmospheric Control System filters controls the temperature and humidity of the air coming into the ship at all times, including the air being used by the engines. It removes any radioactive, chemical or biological impurities, thereby protecting the crew and the systems even during a nuclear, biological or chemical attack," said Vice Admiral Malhi.

The total indigenous efforts account for over 60 percent of ship cost. It also has stealth features against radar and heat seekers and through technical means its underwater signatures have also been reduced.

The cost of building each Shivalik class frigate will be close to Rs 2,800 crore. The construction of the ship has been done under the massive modernisation that the Indian Navy is undertaking to increase its fleet strength.

Weapon and Technology: INS 'Shivalik' -- the S-class Stealth Frigate

Another Detailed One:

SHIVALIK: India's New Generation Warship