(Kaichu type submarine scanned from "Submarines of the
Imperial Japanese Navy" by Polmar and Carpenter)
IJN Submarine RO-39:
Tabular Record of
© 2001-2016 Bob Hackett & Sander Kingsepp
8 August 1942:
Laid down at Sasebo Navy Yard as
a 960-ton type K6
6 March 1943:
Launched as RO-39.
1 August 1943:
LtCdr (Cdr, posthumously) Tachigami
Rikuta (60)(former CO of RO-68) is appointed Chief Equipping Officer.
12 September 1943:
Sasebo. RO-39 is completed and attached
to Maizuru Naval District. Assigned to SubRon 11 for working-up. LtCdr
Tachigami is the CO.
25 December 1943:
RO-39 is assigned to Captain (Rear Admiral,
posthumously) Shimizu Taro's (48) SubDiv 34, Sixth Fleet.
28 December 1943:
Departs Maizuru for Truk.
6 January 1944:
Arrives at Truk.
17 January 1944:
Truk. HEIAN MARU transfers stores to RO-39.
20 January 1944:
RO-39, with ComSubDiv 34, Captain Shimizu embarked,
departs Truk to patrol in the Woleai area, Caroline Islands.
22 January 1944:
Ordered to rescue aircraft crews of 531st NAG
(Woleai) and 755th NAG (Maloelap).
30 January 1944:
RO-39 is ordered to proceed to an area 200 miles
NE of Wotje, Marshall Islands and attack an American invasion fleet.
31 January 1944: American Operation "FLINTLOCK" - The Invasion of the
Vice Admiral (later Admiral) Marc A. Mitscher's (USNA '10) Task
Force 58 lands the 4th Marine Division and the Army's 7th Infantry Division that
capture the Kwajalein, Roi-Namur and Majuro atolls.
2 February 1944:
10 miles E of Wotje. At 0418, LCdr Henry. E.
Townsend's USS WALKER (DD-517), escorting TU 50.15.2, picks up a surface contact
on her radar. WALKER closes and fires a spread of starshells that illuminate a
diving submarine. WALKER tracks the submarine - probably RO-39 - on sonar from
2,500 yds and then drops five depth charges. A large carpet of oil is later
observed at 09-24N, 170-32E. 
6 February 1944:
Takagi orders RO-39 to abort her mission and return.
10 February 1944:
RO-39 fails to acknowledge to the second order to
5 March 1944:
Presumed lost E of Wotje with all 70 hands.
30 April 1944:
Removed from the Navy List.
Authors' Notes:  On 2 February at 1038 (JST), the Sixth Fleet HQ at Truk
received a heavily garbled distress signal from RO-39. Considering that it is
possible that RO-39 survived the initial attack and she was the submarine sunk by
USS CHARRETTE (DD-581) and FAIR (DE-35) in that same area two days later.
The FRUMEL (Fleet Radio Unit at Melbourne) intercepted several radio messages
addressed to RO-39 from the 4th Taroa Air Base and Wotje air base on 4 February
and concluded that RO-39 was probably involved in evacuating certain personnel
from those bases.
Thanks go to Dr. Higuchi Tatsuhiro of Japan. Special thanks go to Hans
Mcilveen of the Netherlands for info on FRUMEL intercepts.
– Bob Hackett and Sander Kingsepp.
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