IJN Submarine RO-44:
Tabular Record of
© 2001-2017 Bob Hackett & Sander Kingsepp
14 February 1942:
Tamano. Laid down at at Mitsui Zosensho as a 960-ton type
1 November 1942:
Numbered RO-44 and provisionally attached to
Maizuru Naval District.
11 November 1942:
Launched as RO-44.
25 July 1943:
LtCdr (later Cdr) Hashimoto Mochitsura (59)(former CO of
I-158) is appointed the Chief Equipping Officer (CEO). 
13 September 1943:
Completed and attached to Maizuru Naval District.
Assigned to Rear Admiral Ishizaki Noboru's (42)(former CO of HYUGA) SubRon 11
for working-up. LtCdr Hashimoto Mochitsura is the Commanding Officer.
13-14 November 1943:
Ise Bay. RO-44 conducts tests with an aircraft
search radar borrowed from the Kure Naval Air Station. SubRon 11 reports the
results of the tests, but is rebuffed for conducting tests without the approval
of the Navy Technical Department.
Departs Kure for the Maizuru Navy Base.
25 December 1943:
RO-44 is reassigned to Captain (Rear Admiral,
posthumously) Shimizu Taro's (48) SubDiv 34 in Vice Admiral (Admiral,
posthumously) Takagi Takeo's (39)(former CO of MUTSU), Sixth Fleet.
28 December 1944:
Departs Maizuru for Truk.
6 January 1944:
Arrives at Truk.
12 January 1944:
Truk. HEIAN MARU transfers stores to RO-44.
15 January 1944:
Departs Truk on her first war patrol to Espiritu
Santo area. No contacts with the enemy are made.
27 January 1944:
Truk-Guam shipping lanes. Lookouts on Cdr (later
Captain) Robert E. Dornin's (USNA '35) USS TRIGGER (SS-237) sight the conning
tower of an RO-class submarine - probably RO-44 - dead ahead. Dornin sets up to
fire a bow shot from 800 yards. He comes to periscope depth and sees the
Japanese submarine, now less than 100 yards away, is preparing to attack.
Expecting an incoming torpedo, Dornin takes TRIGGER to 150 feet, but his
soundman hears no torpedo noises. Dornin comes back up to periscope depth and
sees the Japanese's periscope. When he next returns to periscope depth, the
RO-boat has disappeared. 
31 January 1944: American Operation "FLINTLOCK" - The Invasion of the
Task Force 58 lands the 4th Marine Division and the Army's 7th
Infantry Division. They capture the Kwajalein, Roi-Namur and Majuro atolls.
17-18 February 1944: American Operation "HAILSTONE" - The Attack on
Task Force 58's five fleet carriers and four light carriers, supported
by six battleships, ten cruisers and 28 destroyers, launch air attacks on
Japanese ships in the lagoon, airfields and shore installations. They sink 31
transports and 10 naval vessels (two cruisers, four destroyers and four
auxiliary vessels), destroy nearly 200 aircraft and damage severely about 100
During the attacks, RO-44 returns to Truk from the Espiritu Santo area.
She is ordered to take a holding position 40 miles NE of Truk to intercept the
18-21 February 1944: American Operation "CATCHPOLE" - The Invasion of
The V Amphibious Corps Reserve (Marine 22nd Regiment and the
Army's 106th Infantry Regiment) capture Engebi Island, Eniwetok and Parry
After passing Jaluit, RO-44 approaches Mili, but sights
an American battleship and two aircraft carriers. LtCdr Hashimoto cannot gain
attack position due to the American's superior speed.
21 February 1944:
Returns to Truk.
28 February 1944:
Departs Truk for Mili carrying cargo of food,
ammunition and a set of new code books.
1 March 1944:
Soon after departure the clamps securing the rubber
containers on the afterdeck give way and the whole shipment is washed overboard.
LtCdr Hashimoto heads back to Truk.
2 March 1944:
Departs Truk on a new supply run to Mili, carrying a
total of 11-tons of food and ammunition. RO-44 is also ordered to reconnoiter
Majuro Island on her way back to Truk.
9 March 1944:
After passing Jaluit, RO-44 approaches Mili from the
west and sights a task force comprising two carriers, a battleship and a
cruiser, all heading SE. At 0545 (JST), LtCdr Hashimoto commences an approach
for a four-torpedo salvo, although the distance is too far. He surfaces and
chases the task force for about an hour. Suddenly, six destroyers appear and
force RO-44 to dive.
11 March 1944:
Arrives at Mili. At night, the cargo is disembarked.
Departs Mili, carrying 17 passengers.
13 March 1944:
At dawn, when RO-44 is conducting periscopic
reconnaissance, a line of red and white lights is sighted.
About 2300, while approaching Majuro, a red light is sighted ahead. RO-44
crash-dives. At periscope depth, the number of lights increases as the submarine
gets closer to the atoll. LtCdr Hashimoto believes the lights he sees are on an
14 March 1944:
By 0330, the lights are seen to be coming from American
warships - an aircraft carrier, eight battleships and tank landing craft. The
nearest battleship is only 500 yards away! Hashimoto decides not to endanger his
supply mission by attacking. Instead, he reconnoiters Majuro and reports his
sightings to Headquarters, Combined Fleet: "The Majuro anchorage is full of
battleships and other capital ships”.
29 March 1944:
Returns to Truk.
11 April 1944:
Departs Truk for a position S of the island.
15 April 1944:
Returns to Truk.
17 April 1944:
B-24 "Liberators" raid Truk. RO-44 and RO-42 dive, but
receive minor damage by near misses underwater.
20 April 1944:
Truk is bombed again. RO-44 and other submarines
submerge to the bottom of the shallow 75 foot deep anchorage, but when LtCdr
Hashimoto surfaces he finds his periscope has been damaged in the raid. It can
only be repaired in Japan.
RO-44 departs Truk via Saipan for Kure. Enroute, she is bombed and
strafed by an American aircraft, but only damaged slightly by machine-gun
29 April 1944:
Arrives at Kure for repairs and overhaul.
14 May 1944:
Lt (LtCdr, posthumously) Uesugi Sadao (65)(former torpedo
officer of RO-500) is appointed the CO.
That same day, RO-44 departs Kure for Saipan.
20 May 1944:
Arrives at Saipan.
23 May 1944:
Departs Saipan to reconnoiter Eniwetok, Marshall Islands.
11 June 1944:
Lt Uesugi reports about his observation results and
heads for the area NE of Eniwetok.
13 June 1944:
Carries out a periscope observation of Brown Island,
Eniwetok. Receives an order to proceed to the Marianas area at flank speed.
15 June 1944: American Operation "FORAGER" - The Invasion of Saipan:
Vice Admiral (later Admiral) Richmond K. Turner's (USNA '08) (former CO of
ASTORIA, CA-34) Task Force 52 lands Marine LtGen Holland M. Smith's V Amphibious
Corps and the invasion begins. That day, LtCdr Uesugi reports the results of his
reconnoitering of Brown, then proceeds towards Saipan. RO-44 is MIA thereafter.
16 June 1944:
110 miles E of Eniwetok. LtCdr E. B. Fay's USS
BURDEN R. HASTINGS (DE-19) makes radar contact with a surfaced submarine. She
closes and challenges with her Aldis lamp, but there is no reply and the
LtCdr Fay fires two barrages of twenty-four Mark 10 "Hedgehog"
ahead-thrown projector charges and drops four depth charges that sink the
submarine at 11-13N, 164-15E. At daybreak, an aluminum plaque with "RO-44" on it
is recovered from the debris.
That same day, RO-44 is ordered to assume a position SE of the Marianas.
12 July 1944:
Presumed lost with all 72 hands off Saipan. Lt Uesugi
is promoted LtCdr posthumously.
10 August 1944:
Removed from the Navy List.
 Cdr Hashimoto's first name is misspelt as "Iko" in several
A review of all RO-class TROMs indicates that RO-44
likely was the unidentified RO-boat.
Thanks go to Dr. Higuchi Tatsuhiro of Japan. Special thanks for assistance
in researching the IJN officers mentioned in this TROM go to Mr.
Jean-François Masson of Canada.
– Bob Hackett and Sander Kingsepp
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