May 1, 2012

Indian Submarines Chakra & the ATVs Make Progress

As at Aug 27, 2008


2 Russian Akula IIs - similar (perhaps) to the final form of INS Chakra


Likely Plan of India's Advanced Technology Vessel (ATV) which may be launched next year. This ".jpg" image originated here.
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On August 21, 2008, a confusing article from India Today stated (paragraphs reorganised to attempt to provide clarity):
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INS Chakra - Modified Akula II
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"India's strategic establishment has begun the countdown to two important milestones. In late June, a modified Akula-II class nuclear-powered attack submarine, the Chakra, began harbour acceptance trials at the Komsomolsk-on-Amur shipyard [inland about 1,000 kms northeast of Vladivostok] in the Russian far east.
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The Chakra is the Russian submarine, formerly [commissioned Nerpa in December 2000], which in the next few months will to sail into the Pacific Ocean off Vladivostok for full-fledged sea trials with a Russian crew.
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If the trials are successfully concluded, say officials, the Chakra will be commissioned at Vladivostok with an Indian crew who will sail it to India by August 15, 2009.
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Due to its design commonality with ATV, the Chakra is being leased primarily to train crews to man ATVs. With its cruise missiles and torpedoes, it will also be used for sea-denial missions [maybe] in the Indian Ocean.
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The under construction 12,000-tonne Chakra was to be completed and leased to India for 10 years under a $650-million deal signed in 2004. It was to be inducted into the navy on August 15 this year, but was delayed by a year, following technical snags."Project India", as the classified lease programme is called, seems to be back on track after being seemingly caught in last year's freeze in Indo-Russian defence ties over escalating costs of the aircraft carrier Vikramaditya's [ex-Gorshkov] refit.
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Advanced Technology Vessel (ATV) - Modified Akula I
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On January 26, 2009, the sluice gates of an enclosed dry-dock in Visakhapatnam [naval base on India's east coast] are to be opened and the world will take its first look at India's first nuclear-powered submarine, the Advanced Technology Vessel (ATV), as it enters the waters. [complete fitout, testing, crew training may take 4 or 5 years before the first ATV is operational].
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...The aim is to field three [ATV] submarines equipped with nuclear-tipped ballistic missiles-the so-called third leg of the nuclear triad comprising air, land and sea-launched weapons-on "deterrent patrols" (to deter a potential adversary from launching a nuclear first strike) by 2015.
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India's ATV is based on the Russian Akula I class [first launched 1986] submarine, but is powered by a single indigenously-built nuclear reactor and equipped with 12 K-15 ballistic missiles or 16 of the Indo-Russian BrahMos supersonic cruise missiles.
-Background
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naval-technology.com provides the most comprehensive description of the Akula I's and II's that I've seen:
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Data for Akula II:
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Crew 73
Surfaced Displacement 8,140t
Displacement, Submerged 12,770t
Overall Height 11.3m
Hull Cross Section 13.6m x 9.68m
Diving Depth 600m
Run Speed Surfaced 10kt

Speed Submerged 35kt
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Full Specifications
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The Russian Navy has 14 Bars Class project 971 submarines known in the West as the Akula Class nuclear-powered missile attack submarines (SSN). A unknown number of Russian Akula class submarines are deployed in the Pacific and (perhaps) Indian Ocean region.
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The submarines were built by the Amur Shipbuilding Plant Joint Stock Company at Komsomolsk-on-Amur [far eastern Siberia] and at the Severodvinsk shipbuilding yard [near Archangel in nothwestern Russia].

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Seven Akula I submarines were commissioned between 1986 and 1992, and three Improved Akula between 1992 and 1995.
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Three Akula II submarines, with hull length extended by 4m and advanced machinery-quietening technology, have been built.

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[Hence main differences between Akula Is and IIs may be the hull extension and some new equipment.]
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The first Akula II named Viper, was commissioned in 1995, the second, Nerpa, in December 2000 and the third, Gepard, in August 2001. The Akula II are 110m long and displace up to 12,770t.

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DESIGN

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The submarine has a double-hulled configuration with a distinctive high aft fin. The hull has seven compartments and the stand-off distance between the outer and inner hulls is considerable, reducing the possible inner hull damage [due to pressure surges and kinetic punctures?]. The very low acoustic signature has been achieved by incremental design improvements to minimise noise generation and transmission – for example, the installation of active noise cancellation techniques [and the double hull].

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The retractable masts viewed from bow to stern are the periscopes, radar antennae, radio and satellite communications and navigation masts.

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MISSILES
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The Indian fitout is likely to be 16 Indo-Russian BrahMos supersonic cruise missiles first then eventually (say 2015?) replaced or augmented by 12 K-15 ballistic missiles.
The dimensions of the BrahMos missile (8.3 m x 0.6 m) suggest it could[?] be cold launched by torpedo tubes. This would allow eventual simultanous installation of K-15 ballistic missiles and avoid the need to convert vertical launch tubes from BrahMos use to K-15 use.
India test fired a K-15 from a pontoon on February 26, 2008, two-stage, solid fuel, range 700 kms, length 11 metres, 0.7m wide [?]
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Work on the K-15 started around a decade ago under a highly classified programme earlier called
Sagarika (Oceanic). Development ran parallel to the Indian navy's 25 year programme to build the ATV.
A news report estimated the future K-15 "payload" as 500kg. - Comment received: with a 500kg warhead, the range of the Sagarika will be 1800 km. India finds it convenient to understate the range of its missiles though. Having weaponry that can reach Europe causes diplomatic friction.
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Regarding yield, the 250 kg warhead (in a 500kg RV for a K-15 ) may be 200-300kT - this is based on better known calculations for the Agni series warheads. The warheads developed for the Prithvi are smaller (20kT) and lighter (<200kg>20kT. For larger yield (200-300kT) they may use thermonuclear designs. It doesn't appear that India has large fission or
Sloika/Joe 4 type designs. These tend to be heavy and difficult to deliver.
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TORPEDOES
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The submarine has eight torpedo launch tubes, four 650mm and four 533mm tubes. The Improved Akula and Akula II have ten, with six 533mm tubes. The four 650mm tubes can be fitted with liners to provide additional 533mm weapon launch capacity. The torpedo tubes can be used to launch mines instead of torpedoes. The Akula can launch a range of anti-submarine and anti-surface vessel torpedoes.
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SENSORS
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The Akula's surface search radar is the Snoop Pair or the Snoop Half. The surface search radar antennae are installed on the same mast as the Rim Hat radar intercept receiver.
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The submarine is fitted with the MGK 540 sonar system which provides automatic target detection in broad and narrow-band modes by active sonar. It gives the range, relative bearing and range rate.

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The sonar system can also be used in a passive, listening mode for detection of hostile sonars. The sonar signal processor can detect and automatically classify targets as well as reject spurious acoustic noise sources and compensate for variable acoustic conditions.
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PROPULSION
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[Relevant to Chakra ] The main machinery consists of a VM-5 pressure water reactor rated at 190MW with a GT3A turbine developing 35MW. Two auxiliary diesels rated at 750hp provide emergency power. The propulsion system drives a seven-bladed fixed-pitch propeller.
[The single reactor for the ATV was reported in 2004 to be only 100MWt. Unless it has been uprated (or 2 reactors are now to be used) the ATV may be much smaller than an Akula or much slower.]
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The propulsion system provides a maximum submerged speed of 33kt and a surface speed of 10kt. A reserve propeller system, powered by two motors rated at 370kW, provides a speed of 3kt to 4kt. The submarine is rated for a diving depth to 600m.
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Comments
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The January 2009 viewing of an ATV hull may be strongly influenced by the need for good public relations - showing where the Rs Billions spent on a delayed program have gone. Until the ATV hull can be viewed in its entirety press releases about the ATV cannot be fully accepted. Will it basically be an Akula or a heavily modified boat - perhaps smaller?
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Complete fitout, testing and crew training may take 4 or 5 years before the first ATV is fully operational and ready to overawe Pakistan or counter China's SSBNs.
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With the eventual introduction of viable Indian nuclear powered small SSBNs (on top of current Russian and Chinese SSN's and SSBN's) Australia will need to deeply consider whether a conventionally powered Collins class replacement will cut it in a nuclear submarine region.
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We are not labelling Russia, China or India as friends or enemies. Military planning and acquisitions rely more on comparitive capabilities and needs.
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If we calculate that America will be by our side for only 25 years then we should go nuclear (propulsion and weapons). If the Australia-US alliance estimate is optimistic - up to 40 years we don't need to think about nuclear for 20 years - maybe, hopefully.
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