(Kaichu type submarine scanned from "Submarines of the
Imperial Japanese Navy" by Polmar and Carpenter)
IJN Submarine RO-48:
Tabular Record of
© 2001-2016 Bob Hackett & Sander Kingsepp
17 March 1942:
Kobe. Laid down Mitsubishi Shipbuilding as a
960-ton type K6
31 July 1943:
Designated RO-48 and provisionally attached to Maizuru
15 October 1943:
Launched. The submarine receives a different
conning tower, shaped to reduce the radar incident angle. She is fitted with an
E27 Type 3 radar detector prior to the completion.
20 January 1944:
Lt (promoted LtCdr 1 May 1944; Cdr, posthumously)
Ichitomi Kiyota (63)(former CO of RO-58) is appointed Chief Equipping Officer.
31 March 1944:
Kobe. Completed and attached to Maizuru Naval
District. Lt Ichitomi Kiyota is the Commanding Officer. That same day, RO-48
is assigned to SubRon 11, Sixth Fleet, for training.
13 June 1944: Operation "A-GO" - The Defense of the Marianas:
Admiral Toyoda Soemu (33)(former CO of HYUGA), CINC, Combined Fleet, activates
A-Go and orders Vice Admiral Takagi Takeo (39)(former CO of MUTSU), CINC, Sixth
Fleet, to redeploy his boats to the Marianas.
15 June 1944: American Operation "FORAGER" - The Invasion of Saipan:
Vice Admiral (later Admiral) Richmond K. Turner's (USNA ’08) Task Force 52 lands
Marine LtGen Holland M. Smith's V Amphibious Corps and the invasion begins.
Communications between Takagi's Sixth Fleet on Saipan are
disrupted by the invasion. Command of the Sixth Fleet's submarines passes to
Rear Admiral Owada Noboru (44)(former Co of YAMASHIRO), ComSubRon 7 at Truk. He
orders most of the Sixth Fleet's submarines to withdraw from the Marianas.
3 July 1944:
RO-48 is assigned to SubDiv 34, Sixth Fleet (Submarines).
5 July 1944:
Departs Kure on her first war patrol for her assigned
area off Saipan.
10 July 1944:
Vice Admiral Vice Admiral Miwa Shigeyoshi (39)(former CO
of KINU) at Kure assumes command of the Sixth Fleet from Rear Admiral Owada at
12 July 1944:
Arrives at her assigned area within 200 nms of Saipan.
Receives a new order to stand by to rescue IJN pilots from Tinian.
14 July 1944:
At 2130 (JST) when stationed 30 nms N of Saipan, LtCdr
Ichitomi reports that he had been forced underwater and is in process to change
16 July 1944:
Headquarters, Sixth Fleet orders RO-48 to return.
18 July 1944:
360 miles E of Guam. Captain W. V. Saunders' USS
HOGGATT BAY's (CVE-75) Task Group 12.2, a hunter-killer group, is conducting
antisubmarine warfare (ASW) operations off the Marianas. The carrier's radar
picks up a contact on the surface at 21,000 yds.
19 July 1944:
At 0024, Captain Saunders detaches two of his four
screening escorts, LtCdr Edwin P. Parker's USS WYMAN (DE-38) and REYNOLDS
(DE-42), to investigate the carrier's radar contact. WYMAN closes the range
until 0046 when she loses radar contact at 4,000 yds as the contact dives.
WYMAN switches to her sonar and picks up a strong echo at 1,600 yds. At
0051, Parker fires a barrage of twenty-four Mark 10 "Hedgehog" projector
charges, but without results. WYMAN reloads and Parker opens the range, then he
closes for a second attack.
At 0125, Parker fires a second barrage of twenty-four "Hedgehog" charges.
WYMAN is rocked by five underwater explosions as the submarine is blown apart.
Parker attempts to regain sonar contact but the sonar's returns indicate that
the contact has been destroyed. The submarine - probably RO-48 - is sunk at
13-01N, 151-58E. 
15 July 1944:
Presumed lost with all 76 hands off Saipan.
10 October 1944:
Removed from the Navy List.
 Some older sources credit USS GILMER (APD-11) and WILLIAM
C. MILLER (DE-259) with the sinking of RO-48. In reality, their victim was I-55.
 It is possible that USS WYMAN was the attacker of RO-48 on 14 July as
Thanks go to Dr. Higuchi Tatsuhiro of Japan.
– Bob Hackett and Sander Kingsepp
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