What types of torpedoes were there?

Torpedoes can be classified by method of propulsion and whether they were homing or aimed. During WW2, great advances were made in torpedo design. However, they were still rather basic compared to current weapons.

The most common methods of propulsion were by electric battery, steam from fossil fuels, or diesel engines. The British used diesel engines. We will focus here on American torpedoes which were either steam driven or were battery-driven electric weapons.

Electric torpedo – a torpedo that was powered by a battery and an electric motor. The torpedo seen on the USS Pampanito (SS-383) museum in the forward torpedo room on the starboard side was electric.

Steam torpedo – a torpedo that had a steam engine. Steam was produced with a volatile fuel - generally alcohol – along with air and pure water in an internal combustion chamber. The steam was then directed into a turbine to drive the propellers. Steam was not added to the torpedo prior to firing.  It was generated inside the torpedo upon firing.

Aimed torpedo – the torpedo was given a final course to collide with a target. Regardless of what the target did, the torpedo was not designed to change course.

Homing torpedo – the torpedo would search for the target, typically using a sonar. It would be aimed towards the target and would then respond to changes in course or speed by the target.