“The system coordinated by the Axis nations was rather complex. German, Italian and Japanese submarines and supply ships operated annually. Transfers were made at specific rendezvous points where exchanges took place between the submarines and the supply ships. The ‘MONSUN’ bases at Penang and Singapore were also extensively used by the long-range cargo submarines. German ‘MONSUN’ submarines made frequent exchanges of raw materials from the Far East for German torpedoes in the southwestern Indian Ocean.

With the fall of the Italian Fascist regime on 8 September 1943, the Imperial Japanese Navy seized Italian submarines operating out of Sebang and Singapore. The Japanese then transferred them to the German Navy. The Germans also seized all of the Italian submarines in Bordeaux. Henceforth, the shipment of cargo between Europe and the Far East would now be conducted solely by German and Japanese forces.”

HARRY’S NOTE - The Italian U-Boats & big German U-Boats that made the long-range voyages to the Far East (as well as to South America) for supply and ‘spook’ missions mainly came from the 12th U-Bootflottille based at Bordeaux up the Gironde River.

“Throughout the entire war, little tonnage was transported via submarine. the special purpose cargo submarines were never completed by the Germans. The standard submarines that were employed were only capable of transporting very limited cargoes. Many of the submarines never reached their destinations. Resources had nevertheless, been exchanged. The European bound cargoes constituting largely of rubber, tungsten, quinine and opium. Japanese procurements on the other hand, seemed to have increased as the war progressed. Typical cargoes bound for Japan included steel, aluminum bars, welding steel and armament systems such as bomb prototypes, blueprints for bombsights and tanks, anti-aircraft guns and munitions. Japan was to secure a substantial amount of Axis military aid.

Included in the Axis submarine operations, there were also frequent military attaché exchanges. In 1942, a Japanese exchange was arranged. The transportation of the officers would be provided by the Imperial Japanese Navy. The maneuver was code named Operation ‘CHERRY BLOSSOM’. On 20 April 1942, the Japanese submarine I-30 left the Penang U-Boat base for Lorient in occupied France. The submarine rendezvoused with a German raider in the Indian Ocean and refueled for the journey to France. On 5 August, I-30 arrived at Lorient under German escort. A tour of Lorient, the largest German U-Boat pen facility, was conducted. Afterwards, the Japanese concluded briefings with German Naval officials. Many such ventures were carried out during the war.

Following the naval exchange of 1942, the German and Japanese naval commands organized for the training of Japanese submarine crews in the Atlantic. In 1943, the arrangement was made. A Japanese crew trained in the North Atlantic for several months on board a German U-Boat. In early 1944, U-1224 was transferred over to the newly-trained Japanese crew. the vessel was re-named Ro-501 by the Imperial Japanese Navy. On the return voyage to Japan however, the submarine was sunk with all hands. The operation had been foiled by American naval supremacy.”

HARRY’S NOTE Ro-501 was destroyed by depth charge attack on 13 May 1944 by the destroyer escort USS FRANCIS M. ROBERTSON to the northwest of the Cape Verde Islands.

“In 1943, Wenneker persuaded the German navy to dispatch two German submarines to Kure, as samples to be studied and copied by the Japanese engineers. On 19 May 1943, U-511 (TYPE IX-C) left France with Vice Admiral Nomura on board. The U-Boat arrived at Kure on 7 August. The following month, U-511 was commissioned into the Imperial Japanese Navy & renamed Ro-500“

HARRY’S NOTE U-511 was the first submarine ever to fire rockets from underwater. These tests were conducted in early summer of 1942 off Peenemünde and U-511 was chosen because the brother of the Skipper, Fritz Steinhoff, had a brother on the staff of Werner von Braun. HEINZ REHSE (254-1987) was an Engineering Petty Officer on U-511 during these tests and he rode her all the way to Japan.

“The other submarine was lost en route to Japan. The Germans had anticipated that the Japanese would use the models to produce more efficient Japanese vessels. This was expected to ultimately aid in the war against Allied shipping to Russia. For some reason however, the Japanese felt that the designs were too complex for reproduction in Asia. No further studying of the submarines was conducted. The Japanese Navy employed Ro-500 until the end of the war. The submarine was eventually surrendered in Maizuru Harbour in August of 1945. Deficient Japanese reproduction techniques plagued the collaboration exchanges of materiel, which had been so costly to organize.

The exchange of war materiel by the German blockade runners and by the joint cargo submarines had constituted a tremendous expense on both of the Axis partners. Although the German Navy bore the brunt of the transportation burden, the Japanese had provided ample supplies and base facilities. On the whole, both nations obliged in their responsibilities to one another, although petty differences did exist among the foreign partners. Overall however, operations ran as planned. The Germans received a reasonable amount of desperately required materiels and the Japanese received a variety of equally necessary technical aid. As mentioned earlier, the German military was initially reluctant to trade its advanced arsenal. By 1944 however, Germany complied with the Japanese desires. In the end, Japan received countless military armaments systems. Her own inability to reproduce specimens in mass, would lead to her end.

More Imperial Japan and the Third Reich

Part I
Part II
Part III
Part IV
Part V
Part VI
Part VII
Part VIII
Part IX
Part X
Part XI