(GYOKO MARU, prewar)
IJA Transport GYOKO MARU:
Tabular Record of Movement
© 2013-2016 Bob Hackett
Glascow, Scotland. Laid down at Napier & Miller, Ltd. Shipyard as
a 5,342 ton cargo ship for Barrie & Nairn, Dundee.
Launched and named DEN OF GLAMIS.
19 July 1912:
DEN OF GLAMIS departs London for Japan.
2 August 1913:
Departs London for Japan.
13 February 1915: World War I:
At 1700, Royal Navy auxiliary transport DEN OF GLAMIS departs Walfisch Bay, Namibia, SW Africa.
Sold Furness Withy & Co., Liverpool. Renamed TAMAQUA.
Sold to Yamashita Kisen Goshi Kaisha, K. K. Renamed GYOKOH MARU.
Managed by Yamashita Kisen, K. K. Chartered to the Osaka Shosen Kaisha (OSK)
22 May 1922:
Departs Singapore for Osaka.
2 February 1931:
Arrives at Seattle, Washington.
5 December 1934:
Arrives at Edithburgh, Australia. Loads 2,000 tons
of gypsum for Hong Kong.
The Second Sino-Japanese War begins. GYOKOH MARU is
chartered by the Imperial Army (IJA) as a troop ship.
13 September 1937:
GYOKOH MARU departs Moji for secret location "A" in
a convoy also consisting of transports, HANGKOW, KIMI, MEIGEN, OME, SAMARANG,
TAKAO, TATESHI, TONE, UGO, UME and YUKI MARUs. GYOKO MARU carries 465 men and
407 horses of the 14th Field Medium Artillery Regiment including most of the
regiment’s ammunition train, 1st Company and part of 1st Company, Transport
Unit, 6th Field Medium Artillery Brigade.
14 September 1937:
Arrives at secret location "A" and begins
3 November 1937:
GYOKOH MARU departs the Goto Islands in a convoy also
consisting of ALASKA, BUZEN, ENGLAND, HAKODATE, INDUS, KAISHO, KOSHIN, MINAMOTO,
SANDAI. SHINTAN, SHOKYU, SHUNSEI, SUEZ, TOKUSHIMA and ZENOAH MARUs escorted by
5 November 1937:
Arrives at Hangzhou Bay, an inlet of the East China
Sea, lies south of Shanghai and ends at the city of Hangzhou. The bay contains
many small islands called the Zhoushan Islands.
10 November 1937: - The invasion of Hangzhou Bay:
40 transports of the
invasion convoy that departed Osaka on 30 October escorted by five destroyers
land LtGen Suematsu Shigeharu’s 114th Division at Hangzhou Bay.
The 1st Squad is led by destroyer YUZUKI and consists of transports
GYOKOH, ALASKA, BUZEN, ENGLAND, HAKODATE, INDUS, KAISHO, KOSHIN, MINAMOTO,
SANDAI. SHINTAN, SHOKYU, SHUNSEI, SUEZ, TOKUSHIMA and ZENOAH MARUs
The 2nd Squad is led by destroyer MIKAZUKI and consists of transports
BEIJING, FUSHIMI, HORAI, JUYO, KARAFUTO, KURETAKE, MEIKO, SHINYO, SHIN YUBARI,
SHINSEI, TAIAN and YAMATO MARUs.
The 3rd Squad is led by destroyer MOCHIZUKI and consists of transports
DAIMON, ETO, FUKUSHO HAKUSHIKA, KANKO, MALACCA, NAVEL, OIRDONO, SHINAI, SHUKI
and TASMANIA MARUs and YOSHIDA MARU No. 1.
Returned to her owners. Renamed GYOKO MARU.
GYOKO MARU is requisitioned by the Imperial Army (IJA) as a troop ship. Alloted IJA No. 244.
29 May 1942:
At 1030, GYOKO MARU departs Futtsu, Tokyo Bay for Miike and other ports in a convoy
also consisting of cargo ships HAKKO, SHICHISEI and TATSUHA MARUs and tankers MATSUMOTO MARU and KYOEI MARU
No.3 escorted by destroyer HATAKAZE.
25 February 1943:
GYOKO MARU departs St Jacques in convoy No. 561 also
consisting of ENJU, NORFOLK, RIKKO and TAISHO MARUs without escort.
28 February 1943:
Arrives at Singapore.
31 May 1943:
The IJA releases GYOKO back to her owners.
12 August 1943:
At 0600, GYOKO MARU departs Yokohama in convoy No. 7812 also consisting of HIYOSHI and RYUSEI MARUs escorted by
14 August 1943:
At 0720, arrives at Kobe
29 September 1943:
GYOKO MARU departs Manila in convoy No. 864 also consisting of KISO, SORACHI,
TACOMA and USSURI MARUs escorted by destroyer FUYO.
Arrives at Takao. FUYO is detached. Convoy No. 864 departs with an unknown escort.
E 7 October 1943:
Arrives at Moji.
19 February 1944:
At 1500, GYOKO MARU departs Mutsure for Takao,
Formosa in convoy MOTA-05 also consisting of ore carrier HIOKI (5320 grt), HOREI, NICHIREI, SHONAN and TAKEKAWA and TEIKON (ex-German WINNETOU) MARUs
and an unidentified merchant escorted by kaibokan IKI. At an unknown date TAKEKAWA MARU is detached for Shanghai.
23 February 1944:
At 0510, LtCdr Ralph M. Metcalf’s (USNA '35) USS POGY (SS-266) torpedoes TEIKON MARU, but she does not sink. A few minutes later, Metcalf also torpedoes HOREI MARU that goes
dead in the water. IKI does not counter-attack. SHONAN MARU takes HOREI MARU in tow, but she splits in two and sinks off Naha harbor, Okinawa. After the attack, the convoy commander in IKI
orders the convoy to alter course and to take shelter at Naha Harbor.
According to Japanese radio traffic intercepted and decoded by ULTRA, at 1030, GYOKO MARU is NW of Sachibaru-saki (a.k.a. Sakihara-saki) Lighthouse, Naha Harbor, Okinawa, when a fire
of undetermined origin breaks out among her cargo of exlposives. Shortly afterwards, there is a great explosion and GYOKO MARU bursts in flames. The fire also damages houses on the nearby shore.
The ship settles down to the bottom and is totally gutted by fire at 26-15N, 127-40E. Six crewmen are killed. 
 Reports on the loss of GYOKO MARU vary. According to her owner's records, GYOKO MARU was torpedoed on the given date by an enemy submarine and beached at Naha Harbor.
She went up in flames and settled to the bottom. Six crewmen perished (the owner's record lists the namesof all six sailors).
Author Komamiya states that GYOKO MARU was torpedoed at about the same time as the other two ships (HOREI MARU and TEIKON MARU), but ULTRA has no record of GYOKO MARU
being hit by an enemy sub at this time. According to ULTRA, at 0515, HOREI MARU radioed that she had been torpedoed at 26-24N, 126-11E, and at 0547, TEIKON MARU radioed that had
been torpedoed at 26-17N, 126-11E.
Another source claims that on 23 Feb '44, GYOKO MARU was attacked by ten aircraft and sunk.
It is also conceivable that GYOKO MARU was actually hit by POGY, possibly a dud or a muffled explosion that caused shifting of her cargo of explosives resulting in a small fire initially.
Possibly the fire was only discovered after her arrival at Naha and by then it was too late. But all time data really do not fit together. As already shown, ULTRA gives full extent
of GYOKO MARU´s demise originating from intercepted radio traffic as early as at 1030 on 23 February 1944. ULTRA further states that GYOKO MARU was a member of convoy MOTA-03 (not MOTA-05).
There is no clear evidence when the undamaged ships of MOTA-05 arrived at Naha Harbor. When IKI ordered the convoy to a shelter at Naha, the convoy was about 70 nm W of Naha Harbor.
There was no air attack on the fleeing ships. Considering GYOKO MARU´s speed of 10.5 knots (at best) it would have been impossible for her to cover the distance to Naha Harbor in about 5 hours.
HOREI MARU towed by SHONAN MARU arrived on 24 February 1944. At 1650, HOREI MARU was blown ashore near Sachibaru-saki in a gale. At 1743, the hull broke in two.
Thanks go to the late John Whitman and Fontessa-san of Japan for info about 1937 troop movement. Thanks also go to Erich Muethlthaler of Germany for most of the info in the footnote.
- Bob Hackett
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