How do torpedo engines work under water?
A torpedo is essentially a guided missile that happens to “fly” underwater (see How Cruise Missiles Work for details on missiles). A torpedo therefore has a propulsion system, a guidance system and some sort of explosive device. Torpedoes can travel several miles on their way to the target, and therefore they need a propulsion system that can run for 10 to 20 minutes. Most missiles that fly through the air use either rocket engines or jet engines , but neither of these work very well underwater. Torpedoes use one of two techniques for propulsion: • Batteries and an electric motor — This is the same technique that any non-nuclear submarine must use when running underwater. • Engines that use special fuel — Most engines that we are familiar with, like car engines and jet engines, draw their oxygen from the air around the engine and use it to burn a fuel. A torpedo cannot do that, so it uses a fuel that
