(Kaichu type submarine scanned from "Submarines of the
Imperial Japanese Navy" by Polmar and Carpenter)
IJN Submarine RO-44:
Tabular Record of
© 2001-2016 Bob Hackett & Sander Kingsepp
14 February 1942:
Tamano. Laid down at at Mitsui Zosensho
as a 960-ton type K6
11 November 1942:
Launched and designated RO-44.
25 July 1943:
LtCdr (later Cdr) Hashimoto Mochitsura (59)(former CO
of I-158) is appointed Chief Equipping Officer.
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 work-up and training. LtCdr Hashimoto is the Commanding Officer.
13-14 November 1943:
Iyo Nada, Inland Sea. RO-44 conducts tests with
a Type 13 air 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.
Transferred from Kure to 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 1943: Departs Maizuru for Truk.
6 January 1944:
Arrives at Truk.
12 January 1944:
Truk. HEIAN MARU transfers stores to RO-44.
15 January 1944:
At 1630 (JST) departs Truk via the South Channel
on her first war patrol to Espiritu Santo area.
27 January 1944:
Truk-Guam shipping lanes (10-53N, 147-14E). At 1224
(K), 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. The submarine is zigzagging radically on base course 120 at 13 kts.
Dornin dives and sets up to fire a bow shot from 800 yards. When Dornin comes
to periscope depth, he sees the Japanese submarine, now less than 100 yards
away, preparing to attack.
Expecting an incoming torpedo, Dornin takes TRIGGER to 150 feet. When
his soundman hears no torpedo noises. Dornin comes back up to periscope depth
and sees the enemy boat retiring at 15 kts. TRIGGER attempts to chase her
adversary, but fails to overtake the enemy boat. At 1435 the contact is
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 intercept an enemy task force with two battleships, two
cruisers and two destroyers sighted 40 miles NE of Truk.
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 Atoll,
Marshall Islands, and sights an American battleship and two aircraft carriers.
LtCdr Hashimoto cannot gain attack position due to the American's superior
21 February 1944:
Returns to Truk.
28 February 1944:
Departs Truk for Mili, carrying a 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. On her way back to Truk, RO-44 is
ordered to reconnoiter Majuro Island.
9 March 1944:
After passing Jaluit, RO-44 approaches Mili Atoll
from the west and sights a task force comprising two carriers, a battleship and
a cruiser, all heading SE. At 0545 (JST), Hashimoto commences an approach for a
four-torpedo salvo, although the distance is excessive. 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 of Majuro Island, 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 holding position S of the island to
intercept a reported enemy task force.
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 Commanding Officer. LtCdr Hashimoto is later
reassigned as the Chief Equipping Officer/CO of I-58, under construction at the
Yokosuka Navy Yard.
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 periscopic 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, Lt 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, a top of a spare parts box 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.
10 August 1944:
Removed from the Navy List.
 A review of all RO-class TROMs indicates that RO-44
likely was the unidentified RO-boat.
Special thanks for assistance in researching the IJN officers mentioned
in this TROM go to Mr. Jean-François Masson of Canada.
Thanks also go to Dr. Higuchi Tatsuhiro of Japan.
– Bob Hackett and Sander Kingsepp
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