One diesel submarine was enough for Sweden to ‘sink’ the most modern nuclear aircraft carrier in the US

The latest technology is not always the most effective. In 2005, Sweden demonstrated this in a war simulation with a simple submarine equipped with a type of diesel engine that was invented in the 19th century.

The submarine HMS Gotland of the Swedish Navy “sank” the almighty nuclear aircraft carrier USS Ronald Reagan of the US Navy. His silent Stirling diesel engines with 19th century technology were key to achieving it.

When David destroys Goliath thanks to technology from almost 200 years ago

The United States has some of the most impressive warships in the world. One of them is the USS Ronald Reagana nuclear-powered aircraft carrier that has been in service with the US Navy since 2003.

With 260,000 HP, 3,200 crew members and the capacity to transport 90 airplanes and helicopters, its numbers are simply spectacular. Obviously, the United States spent a lot of money on this ship (more than 6 billion dollars) and used the most modern technology that existed at that time, which is why it was especially striking that a simple Swedish submarine ‘sunk’ it.

USS Ronald Reagan.

You have to use quotes because it was not a real sinking: in a war simulation, the Swedish submarine demonstrated that it would have managed to sink the USS Ronald Reagan in a hypothetical real war. To achieve this, the Swedish submarine, specifically the HMS Gotlandused much older and simpler technology than the American aircraft carrier. That was the key that allowed him to win the “battle” in the simulation that took place in 2005.

Most submarines use nuclear technology for propulsion. It is the most effective in this type of ship because it allows the submarine to be submerged for longer, since diesel ships need to ‘catch’ air from the surface with a certain frequency for their combustion engine to work.

On the other hand, a nuclear submarine is quieter than a diesel one, that is, more difficult to detect by the enemy, who uses sonar at different frequencies to capture any sound, no matter how minimal.

HMS Gotland.

A diesel submarine, due to the type of mechanics it uses, makes more noise and is easier to detect. In nuclear submarines, on the other hand, there are no constant pistons or explosions that set off the sonar, but these submarines are not undetectable because their nuclear propulsion system is very demanding when it comes to cooling and the technology that allows it to do so makes quieter noise. than that of a conventional diesel engine, but it is noise, after all.

To avoid the drawbacks of diesel submarines or nuclear submarines, the Gotland Class submarines of the Swedish Navy combine diesel engines with diesel-electric engines. They are hybrids, but their diesel engines are not conventional, but Stirling type.

This type of mechanics owes its name to its inventor, Robert Stirling, who conceived the Stirling engine in 1816 as an alternative to the steam engine. It is a highly efficient motor that achieves its optimal performance at low speeds, it’s really quiet and can run on liquid oxygen.

Thanks to this, the Gotland submarine has a air independent propulsion (AIP) system and it does not need to come to the surface to get oxygen: it stores it in a liquid state and that allows it to be submerged for weeks, in addition to being less vulnerable thanks to the fact that it does not need to come to the surface.

The Gotland’s two air-independent Stirling diesel engines can propel the submarine or recharge its batteries to supply power to the two MTU diesel-electric engines, i.e. the Stirling engines can also act as generators and allow extend autonomyalways operating in almost total silence. With the advantage that the latter represents in the military field; In the case of the Gotland, the hull design is also optimized to be as undetectable as possible.

How Gotland is almost undetectable by any sonar (active or passive), so it was able to slowly and stealthily approach the USS Ronald Reagan, without any other ship detecting it, and ‘sink’ it in the war simulation that took place in 2005.

SAAB updated the efficient HMS Gotland in 2020.

The most curious thing is that the United States had rented the Swedish submarine to better understand its technology and develop systems that would allow it to protect itself from this type of ships. Logically, the maneuvers tried to be as realistic as possible.

Almost 20 years after that drill, the HMS Gotland is still in service, although in 2020 the company Saab (it no longer makes cars, but continues to operate in other sectors, such as the military) took care of updating it.