An aircraft carrier was ‘sunk’ by a cheap diesel submarine from Sweden

What you need to know: In 2005, the Swedish diesel-electric submarine HMS Gotland participated in a naval exercise with the US Navy off the coast of California. Despite operating against a formidable carrier strike group that included the nuclear aircraft carrier USS Ronald Reagan, Gotland managed to “sink” the carrier several times in simulated attacks over the course of two years.

The submarine’s success was attributed to its advanced stealth capabilities, including a modern Stirling engine that allowed for near-silent operation and greater underwater endurance.

This exercise highlighted the vulnerability of expensive U.S. aircraft carriers to relatively cheap but stealthy diesel-electric submarines, raising concerns about naval strategies against potential adversaries like China or Russia.

A few years ago, during a large-scale naval exercise off the coast of California, a small Swedish diesel submarine sent shockwaves across the maritime world by “sinking” in a war game one of the world’s most advanced warships: a US nuclear power. motorized aircraft carrier.

Let’s sink an aircraft carrier

The year was 2005 and the small diesel submarine HSMS Gotland was participating in an anti-submarine warfare exercise against the US Navy.

The Swedish submarine and its crew were loaned to the US Navy for the purpose of testing anti-submarine technology, tactics and doctrine against a formidable enemy.

Despite having an entire carrier strike group including destroyers, helicopters and planes searching for it, HSMS Gotland managed to sneak past the formidable anti-submarine defensive network around the USS Ronald Reagan and land several simulated “hits” of torpedoes.

To make matters worse, the Swedish submarine managed to replicate its feat several times over two years, alarming authorities in D.C. and emboldening rivals in Moscow, Beijing and elsewhere.

If a small diesel-powered submarine costing about $100 million—or about the cost of two F-18 Super Hornet aircraft out of the dozens aboard a U.S. aircraft carrier—could sink a $100 million supercarrier? 6 billion, so the US Navy would be at a serious disadvantage in the event of a conflict with China or Russia.

It is true that the exercise was just a simulation, and in all likelihood, the outcome could have been different had it been a real-world scenario.

For example, despite its girth and weight, the USS Ronald Reagan has a top speed of over 30 knots, about 35 miles per hour, which is most impressive for a ship that weighs over 100,000 tons. If the HSMS Gotland had been a real enemy, the US aircraft carrier would have collected the torpedoes and initiated evasive maneuvers to avoid them.

Furthermore, as a supercarrier, the USS Ronald Reagan is well armored and could probably withstand a series of attacks from the small Swedish submarine. But although HSMS Gotland might not have sunk the American aircraft carrier, it most likely would have caused significant damage and forced it to withdraw for repairs.

But how could the small Swedish submarine manage to repeatedly “sink” US Navy ships?

Gotland Class – Old technologies with a modern twist

Most countries use diesel submarines instead of nuclear-powered ones due to the cost and technological barrier that the latter entail. But diesel submarines are noisy, slower and can only stay submerged for a few days or weeks without surfacing, compared to a nuclear submarine that can stay submerged for months if necessary.

Understanding the limitations of diesel submarines, Swedish engineers reached back into history and chose the Stirling engine, which was invented in the early 19th century, to power the HSMS Gotland.

The modern version of Stirling engines has allowed the submarine to become almost completely sonar silent, the primary way ships hunt submarines. Several other layers of technology, such as sonar-resistant coating and electromagnets to limit its magnetic signature, also helped the Swedish submarine become almost undetectable.

About the author

Stavros Atlamazoglou is an experienced defense journalist specializing in special operations and a veteran of the Hellenic Army (national service in the 575th Marine Battalion and Army HQ). He holds a bachelor’s degree from Johns Hopkins University and a master’s degree from the Johns Hopkins School of Advanced International Studies (SAIS). His work has been featured in Business Insider, Sandboxx, and SOFREP.

All images are Creative Commons.