Nazi Germany and Japan's Underwater Connection: The Successful and Incomplete Trans-Oceanic Voyages of WW2 Submarines

During World War II, submarines played a critical role in maintaining trade between Nazi-controlled Europe and Japan. These undersea vessels were the last of their kind to serve as the main link between the two combatant nations. The focus of trade during this period shifted to strategic goods such as technical plans and weapon templates. Although the number of transported goods was limited, the voyages made by these submarines were crucial for the advancement of both nations' war efforts.

Submarine Voyages

Only six submarines made successful attempts to cross the Atlantic or Pacific Ocean. Amongst these, five were Japanese submarines, while one was a German submarine. The successful trans-oceanic voyages were made by the following submarines:

I-30 (August 1942) I-8 (June 1943) I-34 (October 1943) I-29 (December 1943) I-52 (March 1944) U-511 (August 1943, German submarine)

One of the most fascinating events during these voyages occurred in April 1943, when Subhas Chandra Bose, a prominent Indian freedom fighter, transferred from the German submarine U-180 to the Japanese submarine I-29. This event stands as the only known civilian exchange between two submarines from different navies during World War II.

Aborted Mission and Notable Cargo

Another interesting submarine undertaking is the aborted mission of the Japanese submarine U-234 in May 1945. She was on a mission to deliver valuable materials from Nazi Germany to Japan. Among the cargo aboard the submarine was experimental technology, including:

Examples of the latest electric torpedoes a Me 262 jet aircraft a Henschel Hs 293 glide bomb 560 kg of uranium oxide

The nature of the uranium cargo, specifically whether it was weapons-grade, remains unclear. The mission was ultimately aborted, leaving many questions unanswered about the potential impact of this advanced technology on the war's outcome.

Strategic Significance of Submarine Voyages

Despite the limited number of goods transported, these submarine voyages were of immense strategic significance. They enabled the exchange of critical information and materials that enhanced both nations' technological and military capabilities. The successful voyages included:

I-30 - August 1942

In August 1942, the I-30 delivered drawings and examples of the Type 91 torpedo, which was used in the infamous Attack on Pearl Harbor.

On the eve of December 1943, the I-29 set sail for German-occupied France. En route, it met with the German submarine U-180. During this meeting, Subhas Chandra Bose transferred to the I-29, marking the only known civilian exchange between two submarines of different navies in World War II.

Conclusion

The submarine voyages between Nazi Germany and Japan during World War II remain a fascinating historical footnote, illustrating the ingenuity and desperation of both nations in the face of war. The missions, though limited, demonstrated the high stakes and interconnectedness of aquatic endeavors during that tumultuous period.