Submarine Torpedoes of World War II: Fuels and Performance

During World War II, submarine torpedoes were crucial weapons for underwater warfare. They were designed with various fuels and oxidizers to achieve optimal range, speed, and effectiveness. Understanding the different torpedoes and their fuels provides insight into the technological advancements of the era.

Fuel Types and Their Performance in World War II Torpedoes

Several different types of fuels were used in WWII torpedoes, each designed to provide specific advantages. Some torpedoes relied on compressed air, which was simple but offered short ranges. However, these torpedoes were exceptionally fast, making them valuable for certain tactical situations.

USA Torpedoes: Ethanol/Water Mix

The United States Navy utilized torpedoes that burned a mixture of ethanol and water. While this fuel was effective, the ethanol used was denatured with methanol to prevent human consumption. The use of a water/ethanol mix as a fuel source was not without its challenges. Ethanol and water mix well and are easily combustible, which was beneficial for torpedo engines. However, the key to achieving a balanced combustion was the stoichiometric ratio; there had to be enough oxygen to react with the fuel but not too much to create excessive heat that could damage the engine.

Japanese Type 93 Torpedoes: Methanol/Ethanol in Pure Oxygen

Japanese torpedoes, specifically the Type 93, were considered among the best of World War II. They burned methanol or ethanol but in pure oxygen, which created a rapid and intense combustion. This design provided more power and superior performance for these torpedoes. The pure oxygen combustion allowed for faster and more effective burning, enhancing the overall effectiveness of the torpedoes.

Reassignments of Fuels for Submarines

By the middle of the war, many submarine torpedoes began to use fuel-burning systems primarily in surface ships and patrol combatants. Submarine torpedoes, on the other hand, often used electricity and electric engines due to safety concerns and the limited range of fuel-burning torpedoes. While the speed and range of fuel-burning torpedoes were higher, their use posed significant risks to the submarines. The transition to electric propulsion ensured that torpedoes could be fired from safer distances, enhancing the safety and effectiveness of underwater operations.

Innovations in Torpedo Fuels

For torpedoes, innovation did not stop with just the fuels. The United States Navy also experimented with the use of ammonia (decaline) instead of alcohols. While it provided more power than some of the earlier fuels, it was more expensive to produce. Similarly, the Soviet Union developed a type of fuel that generated bubbles in the torpedo's wake, which reduced drag and enhanced speed. Despite these advancements, the primary fuels used in submarines remained ethanol/water mix and electric propulsion.

Conclusion

The fuels used in submarine torpedoes during World War II played a crucial role in determining their performance and tactical effectiveness. From the innovative use of water/ethanol mix to the pure oxygen combustion of Japanese torpedoes, these advancements were critical in the evolution of submarine warfare. The transition to fuel-burning systems in surface ships and the reliance on electric propulsion for submarines highlighted the complex balance between speed, range, and safety that shaped the technology of the time.

In exploring these technologies, it is clear that the innovations in torpedoes during World War II were driven by the need for higher performance, greater range, and improved safety. The ongoing research and development in naval technology continue to draw inspiration from these historical advancements.