SENSUIKAN!
(RO-46)
IJN Submarine RO-40:
Tabular Record of
Movement
© 2001-2020 Bob Hackett & Sander Kingsepp
Revision 4
8 August 1942:
Laid down at Mitsubishi's Kobe Yard as a 960-ton type K6 Submarine No. 206.
5 February 1943:
Renumbered RO-40 and provisionally attached to
Maizuru Naval District.
6 March 1943:
Launched.
1 August 1943:
LtCdr (Cdr, posthumously) Kido Yasuo (60)(former CO of
RO-58) is appointed the Chief Equipping Officer (CEO).
28 September 1943:
Kobe. RO-40 is completed, comissioned and attached
to Maizuru Naval District. Assigned to SubRon 11 for working-up. LtCdr Kido
Yasuo is the Commanding Officer.
5 October 1943:
Inland Sea, 3 miles off Murozumi Lighthouse. During a
training cruise RO-40 collides with the sailing vessel OKAKI MARU. Both ships
receive minor damage.
2 December 1943:
Arrives at Tokuyama Fuel Depot to refuel.
4 December 1943:
Departs Tokuyama for Kure. Transferred to Maizuru soon
thereafter.
15 January 1944:
Reassigned to SubDiv 34, Sixth Fleet.
20 January 1944:
Departs Maizuru for Truk. On that day, the USN Fleet
Radio Unit, Melbourne, Australia (FRUMEL) provides the translation of a message
transmitted by RO-40 regarding the shift of communication zones during her
transit to Truk.
23 January 1944:
On that day, FRUMEL provides the translation of a
message transmitted by Truk Base Force:
"Submarine RO-40 arrives tomorrow 24th
by South Channel."
29 January 1944:
RO-40 arrives at Truk.
31 January 1944: American Operation "FLINTLOCK" - The Invasion of the
Marshall Islands:
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 Kwajalein, Roi-Namur and Majuro.
12 February 1944:
Departs Truk for an area E of Gilberts via
Marshalls on her first war patrol. On that day, FRUMEL provides the translation of
a message transmitted by Truk Base Force:
"Submarine RO-40 leaves by South
Channel at 1600 today."
16 February 1944:
45 miles NW of Kwajalein, Marshall Islands. A
submarine makes an approach on a American convoy. At 1742, LtCdr David L.
Martineau's USS PHELPS (DD-360) makes sonar contact at 1,700 yards. PHELPS drops
a pattern of 13 depth charges on the contact. Cdr John W. Ramey's MACDONOUGH
(DD-351) and Lt Franklyn K. Zinn's minesweeper SAGE (AM-111) then join the hunt and
lay patterns of depth charges that sink RO-40 at 09-50N, 166-35E.
20 February 1944:
The CinC, Sixth Fleet, Vice Admiral (Admiral,
posthumously) Takagi Takeo (39) redirects RO-40 to an area between Kwajalein and
Brown Island to raid enemy supply routes between Hawaii, Tarawa and Makin.
4 March 1944:
RO-40 fails to acknowledge the order to return.
28 March 1944:
Presumed lost with all 69 hands in the Gilberts area.
30 April 1944:
Removed from the Navy List.
Authors' Note:
Thanks go to Dr. Higuchi Tatsuhiro of Japan and to Hans Mcilveen
of the Netherlands for info on FRUMEL intercepts
– Bob Hackett and Sander Kingsepp
Back to Submarine
Page
