(UNKAI MARU No. 1, prewar)

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. [1]

2 December 1941:
Conversion for military duty starts at Mitsui Bussan Zosenbu K.K. shipyard.

17 December 1941:
Departs Tama.

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:
Departs Sasebo.

30 December 1941:
Arrives at Kure.

31 December 1941:
Departs Kure.

1 January 1942:
Arrives at Tokuyama.

2 January 1942:
Departs Tokuyama.

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.

Authors' Notes:
[1] 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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