7 August 1943:
Kure. U-511 arrives. Kapitänleutnant Schneewind and his crew are hosted by the CO of the Kure Naval Base, Vice Admiral (Admiral, posthumously) Nagumo Chuichi (36)(former CO of YAMASHIRO). Schneewind and several officers later travel to Tokyo, where they receive decorations from Navy Minister Admiral Shimada Shigetaro (32)(former CO of HIEI) and Chief of the NGS, Fleet Admiral Nagano Osami (28)(former CO of HIRADO).
16 September 1943:
Kure. U-511 is formally handed over, commissioned in the IJN as RO-500 and attached to Kure Naval District. LtCdr Taoka Kiyoshi (55)(former CO of I-54) is the Commanding Officer. [5]
Kure. RO-500 is put through trials and evaluated by a team of IJN engineers led by Constructor Vice Admiral Fukuda Keiji, one of the designers of the YAMATO class battleships. The IJN team is assisted by three German engineers attached to the Naval Technical Institute in Tokyo. After careful study, the engineers point out several shortcomings of the IXC design, such as low underwater speed, unreliable diesel engines, inadequate ventilation and cooling equipment and limited range.
Earlier, a proposition was put forward to launch serial production of Type IXC submarines equipped with Japanese powerplants and weapons (tentatively designated as IXK by the Germans). Vice Admiral Fukuda rejects the proposition and instead recommends that all available resources be devoted to construction of the new I-201-class ("Sen Taka") high underwater speed submarines. Several features of U-511 are used in this design, including the electric welded pressure hull, prefabricated hull section, and re-designed engine mountings to reduce vibration and engine noise.
Late September 1943:
Kure. After teaching handling of the U-boat to the Japanese, U-511's German crew departs aboard the Italian freighter OSORNO bound for Singapore. Later, the crewmen make their way to Penang. [6]
1 November 1943:
RO-500 is attached to the Otake Submarine School for testing and training purposes.
3 December 1943:
LtCdr Taoka is attached to Headquarters, Sixth Fleet. RO-500's torpedo officer Lt Uesugi Sadao (65)(former torpedo officer of I-20) is appointed the acting CO of RO-500.
31 January 1944:
RO-500's torpedo officer Lt Yamazaki Toshio (67) is appointed the acting CO of RO-500.
30 April 1944:
Lt (later LtCdr) Shiizuka Mitsuo (66)(former torpedo officer of I-185) is appointed the CO.
2 May 1944:
Assigned to SubDiv 33 at Kure with RO-62, RO-63 and RO-64. Later that month, RO-500 commences joint exercises with Yokosuka D4Y2 Suisei ("Judy") dive-bombers of the 634th NAG, soon to be embarked on the hybrid carriers of the ISE class. RO-500 acts as the ASW target for the dive-bomber crews.
1 July 1944:
Reassigned to Kure Guard Unit.
5 July 1944:
Lt (later LtCdr) Yamamoto Yoshio (66)(former torpedo officer of I-361) is appointed the CO.
15 August 1944:
RO-500 is in the Kure Naval District with RO-62 and RO-68. Training duties.
15 September 1944:
Lt Yamamoto Yasuhisa (67)(former navigating officer of RO-114) is appointed the CO.
Late September 1944:
The staff of Saeki NAG requests two submarines from the Kure Naval Base HQ to simulate "intruders" for ASW aircraft crews. RO-500 is one of the candidates with RO-68, but cannot participate because of diesel repairs.
5 May 1945:
Reassigned to 51st Escort Squadron at Maizuru to simulate US submarines for subchaser/kaibokan crews.
Kure Navy Yard. I-155 through I-158 are repainted to test the efficiency of the German light grey camouflage scheme. Subsequent trials reveal no advantages over the scheme used on Japanese submarines.
12 August 1945:
Arrives at Maizuru following the Soviet invasion of Manchuria. Embarks fuel and ammunition.
15 August 1945: End of Hostilities with the Allies:
RO-500's crew joins the rebels and decides to continue fighting against the Soviets.
18 August 1945:
Early in the morning departs Maizuru for Sakhalin waters. Sixth Fleet HQ learns about the sortie and addresses the crew of RO-500 by radio. A floatplane manages to locate the submarine and on the evening of 18th she returns to Maizuru.
September 1945:
Maizuru Navy Base. RO-500 is surrendered to Allied Forces.
10 October 1945:
Removed from the Navy List.
13 October 1945:
At Maizuru with I-121, I-201, I-202, RO-18 and RO-68.
30 April 1946:
Sea of Japan. RO-500 is scuttled by the U.S. Navy in the Wakasa Gulf.
Authors' Notes:
[1] This total of ships sunk includes both ships sunk by U-511 while she was enroute to Japan.
[2] One of three sets of Me-163 blueprints carried to Japan by submarine; the others are later carried aboard I-29 and RO-501. Only the Me-163 blueprints carried on U-511 and I-29 make it to Japan. They are used to develop the Mitsubishi J8MI Shusui ("Sword Stroke").
[3] Nomura later becomes the CINC, Kure Naval Station and, as a full Admiral in 1944, Vice Minister of the Navy. Many authors confuse Admiral Nomura Naokuni (35) with Admiral Nomura Kichisaburo (26).
[4] Axis propaganda asserted U-511 was a "gift" from Hitler to Emperor Hirohito. Actually, the Germans treated U-511 as a partial payment for Japanese supplies (raw rubber and torpedoes in particular) already delivered by surface blockade runners. The Japanese and Germans always dealt on a strictly hard currency (or gold) basis.
[4] According to some German sources, Captain Okuda Masuzo had been appointed CO of U-511 by then. This is incorrect, since Okuda was the highest-ranking passenger aboard the submarine during her voyage to Kure. The first Japanese skipper of U-511/RO-500 was appointed on 16 September 1943.
[5] In some postwar German sources the "friendly fire" accident of 29 July has grown into a major naval battle between the U-511 and the surface units of the IJN. Moreover, they state that the "battle" could only be stopped after Vice Admiral Nomura challenged the attackers by radio. In reality, Nomura had already left the sub at Penang, after he developed heart trouble.
[6] U-511's crew later becomes a spare crew for the U-boats that operate from Penang. They also form the backbone of repair and maintenance capability of that small (five U-boat) base.
On 20 Nov '43, Schneewind is given command of U-183 at Penang. He is KIA 23 Apr '45 in the Java Sea when U-183 is torpedoed and sunk by USS BESUGO (SS-321).