[El Gato]

I wonder how much stealth technology that the Swedes are using came from our silent propulsion secrets those bastards at Toshiba sold Russia?

Very little, if any. The Swedes have the capability to develope quieter screws themselves. But what makes this sub so dangerous is it's engines. They are quiet, like a diesel-electric on batteries, but can stay down a long time, and make long moderately fast runs, without having to surface, like a nuke boat. Not quiet so or long or so fast, but long enough and fast enough. Especially in the littoral areas.

The Swedes aren't the only ones going AIP. The Italians, the Japanese and the Germans are as well.

[Amos McCoy]

But what makes this sub so dangerous is it's engines. They are quiet, like a diesel-electric on batteries, but can stay down a long time, and make long moderately fast runs, without having to surface, like a nuke boat.

So, do you think the author is on to something here?

[xkaydet65]

Given that these boats are in service with allied or friendly navies,it would be likely the USN has had ample opportunity to study the systems and develop countermeasures.