Buzz
Torpedoes are powered either by batteries with an electric motor or by a unique type of fuel.A torpedo is a type of guided missile that moves through water (see How Cruise Missiles Work for more details). It includes a propulsion system, a guidance system, and an explosive charge. Torpedoes are capable of traveling several miles to their target, which requires a propulsion system that can sustain operation for 10 to 20 minutes.
While most missiles that fly through the air are powered by rocket engines or jet engines, these do not function well underwater. Torpedoes use one of two methods for propulsion:
- Batteries with an electric motor – This is the method used by any non-nuclear submarine when operating underwater.
- Engines powered by special fuel – Unlike most engines we know, such as car and jet engines, which rely on oxygen from the air for combustion, a torpedo needs a fuel that either doesn’t require an oxidizer or contains its own oxidizer. OTTO fuel (see links below) has its oxidizer mixed with the fuel. Hydrogen Peroxide, as mentioned on this page, doesn’t need an oxidizer.
In our everyday lives, we don't often encounter fuels that contain their own oxidizers, and there are two main reasons for this. Fuels that have their own oxidizer tend to be explosive. Take dynamite, for example, which contains its own oxidizer and is highly volatile (see Question 397 for details on dynamite). Similarly, Rocket engines must carry their own oxidizer. However, since engines typically operate in the air, where oxygen is abundant, carrying the oxidizer only adds unnecessary weight and complexity.
