During war games in 2005, a Single Swedish Gotland-class diesel-electric submarine managed to sneak by the entire US Navy carrier task force with antisubmarine defenses.
Submarine Entered the read Zone and scored multiple torpedo hits on the USS Ronald Reagan Aircraft carrier.
A 100 million dollar submarine managed to destroy a 6.2 billion dollar Aircraft carrier
Yet despite making multiple attack runs on the Reagan, the Gotland was never detected.
This outcome was replicated time and time again over two years of war games, with opposing destroyers and nuclear attack submarines succumbing to the stealthy Swedish sub.
The naval analyst Norman Polmar said the Gotland “ran rings” around the American carrier task force. Another source claimed US antisubmarine specialists were “demoralized” by the experience.
How was the Gotland able to evade Reagan’s elaborate antisubmarine defenses involving multiple ships and aircraft employing a multitude of sensors? And even more important, how was a relatively cheap submarine costing about $100 million — roughly the cost of a single F-35 stealth fighter today — able to accomplish that? After all, the US Navy decommissioned its last diesel submarine in 1990.
Diesel submarines in the past were limited by the need to operate noisy, air-consuming engines that meant they could remain underwater for only a few days before needing to surface. Naturally, a submarine is most vulnerable, and can be most easily tracked, when surfaced, even when using a snorkel.
Submarines powered by nuclear reactors, on the other hand, do not require large air supplies to operate and can run much more quietly for months at a time underwater — and they can swim faster while at it.
However, the 200-foot-long Swedish Gotland-class submarines, introduced in 1996, were the first to employ an Air Independent Propulsion system — in this case, the Stirling engine. A Stirling engine charges the submarine’s 75-kilowatt battery using liquid oxygen.