Tuesday 10 January 2023

Stories From The Deep: Indonesia’s Experimental U-Boat Midget Subs

By Stijn Mitzer and Joost Oliemans
Military enthusiasts are always on the hunt for new captivating war stories. Mark Felton has already done a great job in bringing a great number of elusive war stories to the attention of a worldwide audience, and yet more stories lay hidden in dusty archives or elusive photographs, waiting to one day be uncovered. One such story details the design and construction of Midget U-Boats by a German submariner - working together with Indonesian freedom fighters that had served in the Dutch Navy - on the island of Java in 1947. [1] Though one of the contraptions sank during its first sea trial, their design and construction by a German submariner (rather than an actual designer) in a steel factory with no professional tools means was nonetheless an impressive feat.

The German submariner had been part of the Gruppe Monsun, a force of German (and Italian) U-boats that operated in the Pacific and Indian Oceans during the Second World War. Operating from bases in Japanese-controlled Malaysia, Singapore and Indonesia (then still the Dutch East Indies), this area of operations was the only place where German and Japanese (and Italian) forces actually fought in the same theatre. After Germany's surrender on the 8th of May 1945, the four German submarines and two Italian submarines that had remained present were taken over by the Japanese, with their crews interned in Indonesia or used to operate the now Japanese-controlled submarines.
Interestingly, the two Italian submarines Luigi Torelli and Comandante Cappellini had already been captured by Japan once before. This occurred after Italy's surrender in September 1943. The boats were then handed over to the German Kriegsmarine in Sabang, Indonesia, which continued to operate the submarines with a mixed German-Italian crew. After the surrender of Germany, the two boats (along with the four German ones) were taken over by the Japanese again, now being operated by a mixed German-Italian-Japanese crew! The Luigi Torelli and Comandante Cappellini were the only naval vessels to operate in service of all three main Axis powers during the Second World War. 
While the two Italian submarines mainly saw service as transport submarines between the Dutch East Indies and Japan, ultimately ending up captured by U.S. forces at Kobe, Japan in 1945, the German U-Boats U-181, U-195, U-219 and U-862 were captured by the British in Singapore and the Dutch East Indies. The U-181 (I-501) and U-862 (I-502) surrendered to the British at Singapore, which subsequently scuttled both U-Boats in the Strait of Malacca. The U-195 (I-506) and U-219 (I-505) were captured by British forces in August 1945 at Jakarta and Surabaya, in the Dutch East Indies, respectively. The Dutch were forced to scuttle both U-Boats by the Tripartite Naval Commission in 1946. [2]

The Type XB submarine U-219/I-505. The Dutch Navy was not allowed to keep her and the Type IXD1 submarine U-195/I-506 as a result of rules imposed by the Tripartite Naval Commission and both U-Boats were scuttled off the coast of Java in 1946.

The crew of the U-181 and U-862 captured in Singapore eventually returned to Germany after the war's end or permanently settled in Wales after their interment there. Some of the U-195's and U-219's crew and other Kriegsmarine personnel that remained present in the Dutch East Indies in 1945 chose a different life path entirely. While some surrendered and cooperated with the British, others offered their service to the Indonesian Republic to continue to fight the colonial British and Dutch forces during the Indonesian National Revolution. This included designing and constructing midget U-Boats in a steel factory in Yogyakarta on the island of Java. [2]

The steel contraptions were discovered after Dutch forces captured the Indonesian Republic's temporary capital, Yogyakarta during Operatie Kraai (Operation Crow), the second of two successful military offensives that sought to capture both the Republic's capital and its leaders. Interestingly, the Dutch not only ended up capturing Indonesian President Sukarno and Vice-President Mohammad Hatta, but also five Germans on East Java during the first offensive Operatie Product (Operation Product) in August 1947. Four of these had served on the U-195/I-506 while a fifth (Indonesian-born) German had taken up a career as a dog trainer for Indonesian forces. [3] [4] [5] [6] [7]

Dutch soldiers quizzically inspect the steel contraption they've just captured. Note the stabilising fins fitted to each side of the craft.

Dutch soldiers stand on top of the second Midget U-Boat. This craft is notably more refined than the first iteration. Note the ALRI inscription on the side of the submarine, which stands for Angkatan Laut Republik Indonesia (The Republic of Indonesia Navy).

Crude and inoperative as their design was, the Midget U-Boats were still the first-ever submarine to be assembled and operated by Indonesia. Unfortunately, very little is known about the crafts' inner workings except that their design parameters could not prevent the first prototype from sinking on its first voyage. [8] The steel monster was subsequently raised and brought back to the steel factory for repairs and design improvements, a process that was rudely interrupted by the arrival of the Dutch. Had the submarine been repaired in time, it would likely have seen action against unsuspecting Dutch Navy destroyers that maintained a naval blockade around Republican-held territory on the island of Java.

For this purpose, the midget submarine could be armed with a single torpedo clamped under its hull. [9] This would likely have consisted of the Japanese Type 93 or Type 95 torpedoes or even the 450mm Type 91 Mod 2 aerial torpedo, large numbers of which fell into the hands of Indonesian forces when they captured or were handed over former bases of the Imperial Japanese Navy. [10] The torpedo would have been aimed through a large periscope housed in the sail. Judging by the large round windows on the submarine's conning tower and by the sheer size of the periscope, at least a part of the submarine would stick out of the water during operations, technically making it a semi-submersible.

The attachment clamps for the single torpedo that could be carried.

The final design can only be described as crude at best, bearing no resemblance to any type of midget submarine from that period. A scale model of the submarine made in advance of the actual design looks to have been loosely inspired by the German Biber midget submarine. Whether this is purely a coincidence or if the German submariner had a chance to the view the Biber before his departure to the Dutch East Indies, subsequently using its as a basis for his own design, is unknown. Mass production of the Biber started in the summer of 1944, months before the U-195 and U-216 departed for the Dutch East Indies. Both submarines carried dismantled V-2 rockets and blueprints for advanced weaponry, and its possible that the transfer of Biber blueprints on these voyages was lost to history. Ultimately, the most plausible theory by far remains that the likeness is a mere coincidence.

A German Biber Midget U-Boat.

A model made by the German submariner before he started construction on the full-scale submarine.

German Midget U-Boats designed by a German submariner in the Dutch East Indies armed with Japanese torpedoes after he chose to fight with Indonesian freedom fighters following the surrender of Nazi Germany and Japan – truly, this story has it all. While the submarines were perhaps doomed from the onset by their crude design and cruder production quality, it is an important testament to the increasing determination of Indonesians to (with the aid of others) explore every avenue to take the fight to Dutch forces. It would take until 1962 before Indonesia mounted another attempt at sinking a Dutch capital ship as part of Operation Trikora, Indonesia's plan to invade Dutch New Guinea. By now in the possession of advanced armament acquired from the Soviet Union, the resulting (but eventually aborted) plan called for the sinking of the Dutch aircraft carrier the HNLMS Karel Doorman by Tu-16KS-1 heavy bombers armed with KS-1 Komet anti-ship missiles. Evidently, the fact that Indonesian military history has only received scant coverage in the West reflects poorly the wealth of interesting stories it contains; stories this author is all too glad to uncover.
[1] In een staalfabriek in Djocja werkte een ex-Duitse matroos aan een eenmanstorpedo. Zijn uitvinding mislukte. Bij de eerste proefneming zonk het ijzeren gevaarte. https://www.nationaalarchief.nl/onderzoeken/fotocollectie/af009e5e-d0b4-102d-bcf8-003048976d84
[2] IJN Submarine I-505: Tabular Record of Movement http://www.combinedfleet.com/I-505.htm
[3] Malang: Een van de vijf op 1 augustus 1947 gearresteerde Duitsers: Erich Döring, geboren 29-03-1921 Muehlhausen. In dienst van de Kriegsmarine als Maschinenunteroff. op U-boot 195. https://www.nationaalarchief.nl/onderzoeken/fotocollectie/3fa45cf9-01a6-7884-0237-db4c606ccfa5
[4] Malang: Een van de vijf op 1 augustus 1947 gearresteerde Duitsers: Herbert Weber, geb. 3-6-'14 te Leutersdorf. In dienst van de Kriegsmarine als Leitender Ingenieur op U-boot 195 https://www.nationaalarchief.nl/onderzoeken/fotocollectie/f1cca949-fd26-d1c8-3f3a-10a985539386
[5] Malang: Een van de vijf op 1 augustus 1947 gearresteerde Duitsers: Heinz Ulrich, geboren 14-08-1924 te Berlijn. In dienst van de Kriegsmarine als Maschinenobergefreiter op U-boot 195. https://www.nationaalarchief.nl/onderzoeken/fotocollectie/432b83ec-97d7-308b-08cd-f2470cf2bea8
[6] Malang: Een van de vijf op 1 augustus 1947 gearresteerde Duitsers: Res. Oberleutnant zur See Fritz Arp, geb. 16-1-'15 te Burg auf Friehmar (Ostsee) In dienst van de Kriegsmarine als 1ste Off. op U-boot 195. https://www.nationaalarchief.nl/onderzoeken/fotocollectie/c8569997-e185-7055-81c5-f70cad6da942
[7] Malang. Een van de vijf op 1 augustus 1947 te Malang gearresteerde Duitsers: Alfred Pschunder, geboren op 24 december 1918 te Malang, Rijksduitser. Hij richtte o.a. honden af voor de Polisi Negara https://www.nationaalarchief.nl/onderzoeken/fotocollectie/c8569997-e185-7055-81c5-f70cad6da942
[8] In een staalfabriek in Djocja werkte een ex-Duitse matroos aan een eenmanstorpedo. Zijn uitvinding mislukte. Bij de eerste proefneming zonk het ijzeren gevaarte. Op deze plaats werd de torpedo aan het moeder-scheepje bevestigd. https://commons.wikimedia.org/wiki/File:In_een_staalfabriek_in_Djocja_werkte_een_ex-Duitse_matroos_aan_een_eenmanstorped,_Bestanddeelnr_3150.jpg
[9] In een staalfabriek in Djocja werkte een ex-Duitse matroos aan een eenmanstorpedo. Zijn uitvinding mislukte. Bij de eerste proefneming zonk het ijzeren gevaarte. Op deze plaats werd de torpedo aan het moederscheepje bevestigd https://www.nationaalarchief.nl/onderzoeken/fotocollectie/397950e1-fab7-1892-0a70-7d82a6ca43c8
[10] Hangar met Japanse? voertuigen. In de achtergrond liggen zeetorpedo's opgestapeld https://www.nationaalarchief.nl/onderzoeken/fotocollectie/01ff58e2-1eea-1815-f92d-68bfb852bb8e