September 20, 2005:
After years of negotiations, India has signed a deal to buy
six French Scorpene class diesel submarines. These are similar to the Agosta 90B
subs (also French) that Pakistan has bought. The first of the Agosta's was built
in France, but the other two were built in Pakistan. The third Pakistani Agosta
is still being finished, it was delayed over a year because Islamic terrorists
had killed some of the French engineers working on the project.
The two
designs are similar, with the Scorpene being more recent (and the result of
cooperation between a French and a Spanish firm.) The Agosta is a 1,500 ton
(surface displacement) diesel-electric sub with a 36 man crew and four 21 inch
torpedo tubes (with 20 torpedoes and/or anti-ship missiles carried.) The
Scorpene is a little heavier (1700 tons), has a smaller crew (32) and is a
little faster. It has six 21 inch torpedo tubes, and carries 18 torpedoes and/or
missiles.
Both models can be equipped with an AIP (air independent
propulsion) system. This enables the sub to stay under longer, thus making the
sub harder to find. AIP allows the sub to travel under water for 4-5 days at low
speed (5-10 kilometers an hour). The Pakistanis have an option to retrofit AIP
in their current two Agostas.
With both nations having these modern
subs, they have very lethal weapons against surface warships. With well trained
crews, Agostas and Scorpenes can get close to just about any surface ship, no
matter how good the defenders anti-submarine defenses are. But it's the AIP
boats that are the real killers. Without AIP, subs spend most of their time just
below surface, using their diesel engines (via a snorkel device that breaks the
surface to take in air, and get rid of the engine exhaust.) Snorkels can be
spotted by modern maritime patrol aircraft, and both nations are getting more of
these.
India has not said if it is getting AIP for its Scorpenes. The
price of the contract is quoted as $300 million for each boat. That could
include AIP, because the boats are being built in Indian yards, which have much
lower costs. European built AIP boats go for about half a billion dollars each.
Typically, AIP adds about $100 million to the cost of a sub.