India has earmarked $11 billion for the purchase of six next-generation air-independent propulsion, or AIP, submarines.
The Times of India reports that the order will make India the first non-Western nation to deploy this kind of submarine technology, which is intended to augment and replace the country's diesel-electric submarines.
Diesel-electric subs, which make up the fleets of India and most other countries without nuclear capability, have a fatal flaw: without access to air via surfacing or a snorkel -- which shows up via laser, radar or one's unaided eyes -- they can't run their diesel engines. Instead, they must run only on batteries, limiting the range and speed of the watercraft once submerged.
Conversely, nuclear technology allows American, British and Russian submarines to stay submerged for months without speed limitations.
The anaerobic AIP technology of India's new Scorpène-class submarines, made by French naval defense outfit DCNS, uses compressed oxygen tanks to power a turbine alternator that can charge batteries underwater, allowing the subs to stay below the surface for three weeks at a time.
Countries such as Sweden, Japan, Germany and Italy use watercraft that feature auxiliary AIP power.
It's unclear when India will actually deploy the subs -- the Times of India notes that the project is delayed by three years and over-budget -- and predictions begin at 2018.
Just what kind of AIP, however, is uncertain. While the Indian government has lined up the cash it is as yet unsure which foreign builder will get it. Reportedly Russia, Spain, France's DCNS and Germany's HDW are all in the running for a slice of India's $11bn.
The Register (UK) notes that the technology won't make the subs any faster -- just offer an extended range.
But the new technology's electric drive will make them quieter, doing away with the mechanical ruckus signature of the older subs and helping them operate more covertly.
This post was originally published on Smartplanet.com