Swedish Submarines Are Among the World s Best. What s Their Secret?
Hint: a silent, powerful new engine.
Here s What You Need to Know: Sweden is in a busy neighborhood opposite to Russian naval bases on the Baltic Sea.
For decades, submarines came in two discrete flavors: traditional diesel-electric submarines that need to surface every day or two to recharge their noisy, air-breathing diesel engines, and nuclear-powered submarines that could quietly hum along under the sea at relatively high speeds for months at a time thanks to their nuclear reactors.
The downside to the nuclear-powered variety, of course, is that they cost many times the price of a comparable diesel submarines and require nuclear propulsion technology, which may not be worth the trouble for a country only interested in defending its coastal waters. A diesel submarine may also run more quietly than a nuclear submarine by turning off its engines and running on batteries but only for a very short amount of time