U 511 and the voyages of German and Japanese U-boats between Europe and the Far East
Recently, we added a report about the myths around U 862 and her epic voyage to the shores of Australia and New Zealand to our series “Myths”. This U-boat was one of a total of 15 Kriegsmarine U-boats (U 168/ U 178/ U 181/ U 183/ U 188/ U 195/ U 196/ U 219/ U 510/ U 532/ U 537/ U 843/ U 861 und U 1062), which successfully completed their voyage from bases in Germany, France and Norway to South East Asia to bases established at Penang, Batavia, Singapore and Surabaya. A 16th U-boat has to be added to this list, as also U 511 made it safely from Europe to the Far East, however with a final destination at Japan.
Starting in the Summer of 1943, the Kriegsmarine detached up to 57 U-boats (figures subject to selected criteria) in several groups, initially down to the southern tip of Africa, then to the Indian Ocean, and in the end some of the U-boats even to make it to Japanese bases (Penang, Singapore, Batavia and Surabaya) in Japanese occupied South East Asia, to execute operations from there. The majority of U-boats did not survive these detachments. The U-boats in the Indian Ocean and Pacific (U 862 only) sank 162 vessels with a total tonnage of 839,541 GRT.
The collective designation of these U-boats is commonly known as “Monsoon-U-boats”, although “Monsoon” was the code name given to just the one group of U-boats that actually were tasked to proceed to bases at South East Asia to operate from there.
The voyages of U-boats between Europe, South East Asia and Japan, including the operations of German U-boats from Japanese bases in Japanese occupied South East Asia, were based on the German-Italian-Japanese tripartite agreement (“Three-Power-Pact”) of 27 September 1940 (“Axis” Berlin-Rome-Tokyo) and the tripartite “Agreement on Military Cooperation” of 18 January 1942. Also, it was agreed, to donate to Japan two German U-boats for study and test purposes. U 511 and U 1224 were selected for that. For this purpose, the Type IXC U-boat U 511 left Europe on 10 May 1943 for Japan, arriving at Kure, Japan on 07 August 1943, to be handed over to the Japanese Navy as “Present of the Fuehrer” on 16 September 1943 and re-commissioned as RO-501. The German Type IXC U-boat U 1224 was commissioned initially on 01 September 1943, but re-commissioned as RO-501 by a Japanese crew on 15 February 1944 at Kiel.
The 49 men strong crew was brought from Japan to Europe on board the Japanese submarine I-8, arriving at Brest on 31 August 1943, to go through a full German U-boat training lasting several months. After the commissioning of RO-501 and further combat training the submarine left Kiel on 30 March 1944, to further proceed to Japan after an intermediate stop at Kristiansand, Norway. Sadly, the submarine was sunk during this transit on 13 May 1944 northwest of the Cape Verde Islands. Some 16 U-boats successfully made the long voyage from Europe to bases in South East Asia. In the following period 5 of those (U 168/ U 183/ U 196/ U 537 and U 1062) were sunk during operations in the Indian Ocean using the bases there, further 5 (U 181/ U 195/ U 219/ U 511 has been given to Japan in 1943/ U 862) survived there the end of war in Europe in May 1945, and just 6 of those (U 178/ U 188/ U 510/ U 532 surrendering off Scotland/ U 843 and U 861) ever made it back to Europe.
8 of the 16 U-boats, which came through, were Type IXC U-boats U 168/ U 183/ U 188/ U 510/ U 511/ U 532/ U 537 and U 843), further 6 of those were Type IXD U-boats (U 178/ U 181/ U 195/ U 196/ U 861 and U 862) and the two U-boats designed as cargo U-boats were a Type XB U-boat (U 219), respectively a Type VII F torpedo transport U-boat (U 1062).
In addition to that, 3 submarines of the war ally Italy (Guiliani, later UIT 23, Cappellini, later UIT 24, and Torelli, later UIT 25) successfully made it to South East Asia. UIT 23 later was sunk during a combat patrol from Penang and UIT 24 and UIT 25 survived the end of war in Japan.
Also, the war ally Japan successfully made voyages between the Far East and Europe. 3 Japanese submarines (I-30, I-8 and I-29) made it there and back. Further 2 Japanese submarines (I-34 and I-52) were sunk already during the voyage to Europe and RO-501 (ex U 1224) suffered the same fate during its maiden voyage from Europe to the Far East.
A mere 5 German U-boats (U 168/ U 181/ U 183/ U 532 and U 862) actually left for combat patrols, with departing and arriving at their bases in South East Asia. Besides U 511 as a “present” to Japan, 3 more German U-boats (U 183/ U 510 and U 532) even undertook voyages there and back over 3,000 nmi from their bases in South East Asia to mainland Japan for maintenance (battery overhaul) purposes.
The two Italian submarines, taken over from Italy by the Kriegsmarine in September 1943 and renamed as UIT 24 and UIT 25, executed several transport missions between the bases in South East Asia and to Japan, to eventually remain in Kobe, Japan, for for good for repairs as of February, respectively March 1945, after they have been taken over by the Japanese Navy (UIT 24 became I-503 and UIT 25 became I-504) following the German surrender in May 1945.
The distances to pass between Europe and South East Asia were huge, ranging from 11,200 nmi and 12,500 nmi depending on the point of last departure and first arrival. The duration of the voyages reported from the U-boats ranged from 84 days (U 511) to 171 days (U 188). After the Japanese submarines had carried out already by and large two-way transport missions between the Far East and German bases in occupied France as early as 1942, German U-boats were reassigned for that type of mission in mid-1944 as well, since the voyages of blockade breaking German merchant vessels between Europe and South East Asia and return to had to given up at the end of 1943. Ultimately, U-boats were the last remaining means of direct communication between the war allies Germany and Japan, in particular for shipping war essential material.
The cargo reported on board Japanese U-boats enroute from the Far East to France ranged from personal (a complete U-boat crew, to specialists, to top military or diplomatic personal) to blueprints of Japanese weapon technique, to war-essential raw material and other goods such as caoutchouc, tin, tungsten, zinc, molybden, quinine, opium, coffee, even tons of gold. On their return leg, these U-boats carried, apart from important perso-nal, above all products of German weapon system developments, such as engine parts or blueprints of radar-, missile- and aircraft-designs, but also torpedoes and, remarkably, the a number of gears of famous ciphering device “Enigma”.
Apart from few key specialists and top personal, German U-boats took along similarly important war material. On the leg to the Far East this were above all blueprints and parts of German armament technique, but also raw material of great importance to Japan. Already, we have reported about those in earlier issues of our series (see U 234 and U 864), mentioning in particular the lead and mercury cargo and the unusual load of uranium oxide. Similar to the Japanese submarines, the return leg was used by German U-boats to ship, besides some personal, above all raw material of importance to the German war industry, in particular raw rubber (caout-chouc).
The amount of cargo on board German U-boats and Japanese submarines ranged from about 80 t up to 250 t. If one sums up all successful voyages with cargo on board, it surprises to see that only one quarter of these voyages was the leg Far East – Europe, whereas three quarters were voyages from Europe to South East Asia. The voyages between the Far East and Europe were mainly used to transport specialist personal for training in Germany, whereas the return leg was used essentially to ship weapons technology and blueprints.
Exactly these transport voyages have generated various myths. It became known, often much later, which passenger and what load was taken on board these U-boats. Consequently, rumors started to develop, why these people may have been on board and what the purpose of the cargo was. Rather spectacular, for instance, the transfer of the leader of “India Independence Movement”, Mr. Netaji Subash Chandra Bose, his personal assistant and two Japanese submarine specialists on 26 April 1943 in the Indian Ocean off Mozambique from U 180 to the Japanese submarine I-29, which had made her way to the rendezvous from South East Asia.
Or, the two transport voyages in the last months of the war in 1945 organized by the “Marinesonderdienst Ausland” (= Naval Special Foreign Service) to be executed by U 864 and U 234 and leaving Norway for South East Asia on 07 February 1945 (U 864) respectively 15 April 1945 (U 234), which took along very interesting passengers, ranging from German and Japanese submarine specialists, to missile and aircraft engi-neers, to German Air Force Lieutenant General Ulrich Kessler (U 234) as the designated new Air Attaché at the German Embassy at Tokyo. Also, the cargo on board nourished to some extent odd theories as to their purpose, thereby focusing very much at the blueprints and the alleged building parts of German missile and aircraft technology on several U-boats, as well as the 560 kg uranium oxyde on U 234. The latter is being used by some for very daring assessments about the alleged status of the development of an atomic bomb in Germany and Japan.
The maintenance of a direct sea line of communication between the war allies Germany, Italy (until September 1943) and Japan was of predominantly political importance and was executed in realization of the agreement on cooperation between the Axis Powers. However, the amount of war essential material shipped in each case should not be overestimated. It may be rated “important” at best, as it did not contribute to any war decisive effect. Rather, it should be considered as “symbolic” and demonstrating good will to implement the agreement on cooperation.
If at all, only the blueprints and parts of weapons and gear, such as propulsion systems, aircraft and missile tech-nology, plus the transport of certain specialists may considered to be of some importance, which, in the case of Japan; meant aid by the German Reich certainly more than insignificant. Nevertheless, the mutual “gifts” came, if they ever made it through, much too late and in such small size, that they did not generate any visible benefit, given the situation of the war in Europe and Japan. Therefore, any research is welcome as to the effects of these transported goods on the respective military capabilities of the allies Germany, Italy (until September 1943) and Japan, whereas still existing rumors, in particular the myths about alleged German design and material for possible Japanese developments of jet aircraft, missiles and even an atomic bomb, should be repudiated as such.
- Robert K. Wilcox: Japan´s race against time to build its own atomic bomb, Marlowe 1995
- Rohwer/ Hümmelchen: Chronik des Seekrieges 1939-1945, Stalling, München 1968,
- Jochen Brennecke: “Haie im Paradies”, Heyne, München, 1993.