(UNKAI MARU No. 1, prewar)
IJN UNKAI MARU No. 1:
Tabular Record of Movement
© 2017 Gilbert Casse, Berend van der Wal and Peter Cundall
18 September 1931:
Tama. Laid down by Mitsui Bussan Zosenbu K.K. shipyard for Nakamura G.K. as a 2,225-tons cargo ship.
25 February 1932:
Launched and named UNKAI MARU No.1.
31 March 1932:
Completed and registered at Hiroshi-Jima Agata.
23 August ~ 11 September 1932:
Chartered by Nichiro Gyogyo K.K.
1 October 1935:
Ship owner is restyled to Nakamura Kisen K. K.
5 June 1939:
Departs Nanking (now Nanjing), China.
3 August 1939:
Arrives at Nanking.
Registered port is changed to Kobe.
28 September 1941:
Requisitioned by the IJN.
1 December 1941:
Arrives at Tama. Registered as an auxiliary collier, Otsu category, attached to the Sasebo Naval District under instruction No. 1573. 
2 December 1941:
Conversion for military duty starts at Mitsui Bussan Zosenbu K.K. shipyard.
17 December 1941:
18 December 1941:
Arrives at Kure. Departs there later that day.
19 December 1941:
Arrives at Tokuyama. Departs there later that same day.
20 December 1941:
Arrives at Wakamatsu.
21 December 1941:
Arrives at Shimonoseki. Departs there later in the day.
22 December 1941:
Arrives at Sasebo.
28 December 1941:
The conversion is completed.
29 December 1941:
30 December 1941:
Arrives at Kure.
31 December 1941:
1 January 1942:
Arrives at Tokuyama.
2 January 1942:
5 January 1942:
Arrivers at Yokosuka. Departs there later that day possibly with MEITEN and AKASHISAN MARUs.
7 January 1942:
At 0755, torpedoed by LtCdr (later Captain) Stanley P. Moseley’s (USNA ‘25) USS POLLACK (SS-180) off Miko lighthouse; the ship is hit by one torpedo and disabled at 34-27N, 138-59E. One crewman is KIA. IJN auxiliary transport MEITEN MARU arrives and rescues 53 people. Later that day, MEITEN MARU starts towing UNKAI MARU No. 1 but strong wind and high waves break the towing line. UNKAI MARU NO. 1 is left drifting.
10 January 1942:
At 1000, rescue attempts are ended.
11 January 1942:
At 1400, off Katsuura Bay UNKAI MARU NO. 1 is bombed and sunk by an aircraft of Yokosuka Kokutai.
20 January 1942:
Removed from the Navy’s list under instruction No. 125.
 There were two categories of Kyutansen, (Ko) category with an IJN Captain as supervisor aboard and (Otsu) category without.
Thanks go to Gengoro S. Toda of Japan.
- Berend van der Wal, Gilbert Casse and Peter Cundall.
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