RIKUGUN YUSOSEN

Stories and Battle Histories of the Imperial Army's (IJA) Tankers

(OTOWASAN MARU, prewar )


By Bob Hackett
with Erich Muethlhaler, Peter Cundall and Gilbert Casse

Discussion & Questions

19 August 2017


During the war the Japanese employment of merchants ships was divided into three main administrative categories:
A = requisitioned and operated by the Japanese Army
B = requisitioned and operated by the Japanese Navy with civilian crew (captain often being Navy Reserve)
C = controlled and operated by the Senpaku UnŽeikai (Civilian Shipping Administration)
X = requisitioned by the IJN and converted into armed Naval Auxiliaries with IJN crews (gunboats, minesweepers, etc.)

Beside the above categories, there were many shared employments Army/Civilian (A/C) and Navy/Civilian (B/C). These ships were called Haitosen. Normally, this meant that the vessel on its outbound journey was under Army or Navy control carrying troops, military supplies, etc. and on its return voyage was carrying cargo for the benefit of the civilian owner of ship.

While used by the Army, Haitosen also received Army transport numbers like Army requisitioned vessels (A). Employments by Army or Navy could also be expanded, meaning that the ship was used by Army/Navy for one full turn (outward and homeward voyage) or even a series of voyages.


Special Feature 


The majority of the IJA's tankers were salvaged British and Dutch ships and were part of the more than 2,000 foreign ships seized/raised by the Japanese. Their operation was contracted to civilian shipping companies. Several civilian tankers also were requisitioned by the IJA. There were also about 100 tankers, requisitioned by the Japanese Government's Senpaku Uneikai civilian wartime shipping authority, manned by civilian crews and shared with the Imperial Army. Those above 1,000 tons are listed below:

Tabular Records of Movement (TROMs):
Civilian Tankers in Imperial Army Service
(Classes link to specifications summaries)


OTOWASAN
MARU
Class

Otowasan Maru
(revised 7/23/2017)

Omurosan Maru
(revised 7/14/2017)


KAISOKU
MARU
Class


Kaisoku Maru
(revised 10/1/2016)

OGURA
MARU
No. 1 Class

Ogura Maru No. 1
(revised 7/23/2017)

EIYO
MARU
Class

Eiyo Maru
(revised 1/14/2013)

RIKKO
MARU
Class

Rikko Maru
(revised 7/1/2013)

HOKKI
MARU
Class

Hokki Maru
(posted 10/1/2013)

KUROSHIO
MARU
Class

Kuroshio Maru
(revised 7/8/2017)

KYODO
MARU
Class

Kyodo Maru
(posted 11/1/2014)


TEIKON
MARU
Class

Teikon Maru
(ex-German Winnetou)

(revised 8/1/2013)

PEACETIME
STANDARD
TANKER TM
Class

Nichinan Maru
(revised 1/14/2013)

STANDARD
TANKER 1TL
Class

Hakko Maru
(revised 5/29/2016)


STANDARD
TANKER 1TM
Class

Palembang Maru
(revised 1/14/2013)



Civilian Shipping Authority (Senpaku Uneikai) Requisitioned Tankers
Shared with the Imperial Army
(Classes link to specifications summaries)

TACHIBANA
MARU
Class

Tachibana Maru
(revised 8/4/2017)

TONAN MARU
Class

Tonan Maru
(revised 8/11/2017)


STANDARD
TANKER 1TL
Class

Niyo Maru
(revised 2/19/2012)


STANDARD
TANKER 1TM
Class

Ariake Maru
(revised 1/14/2013)

Ichiu Maru
(posted 7/30/2011)
Ichiyo Maru
(revised 1/14/2013)
Kokuei Maru
(revised 1/14/2013)
Medan Maru
(revised 1/14/2013)
Nanei Maru
(revised 1/14/2013)
Nichinan Maru No. 2
(revised 2/12/2012)
Nichirin Maru
(revised 1/14/2013)
Ogurasan Maru
(revised 1/14/2013)
Otorisan Maru
(revised 8/22/2015)
Sarawak Maru
(revised 1/10/2015)
Seishin Maru
(revised 1/14/2013)
Shincho Maru
(revised 1/14/2013)
Shinei Maru
(revised 1/14/2013)
Tenshin Maru
(revised 1/14/2013)
Yamamizu Maru No. 2
(revised 9/1/2013)
Zuiho Maru
(revised 8/19/2017)
STANDARD
TANKER
2AT Class

Daishu Maru
(revised 10/29/2011)

Daito Maru
(posted 7/7/2012)
STANDARD
TANKER
2TL Class

Seria Maru
(posted 7/1/2013)

STANDARD
TANKER
2TM Class

Ceram Maru
(posted 5/1/2014)



Captured and Foreign Tankers in Imperial Army Service
(Ex-Countries link to specifications summaries)

Ex-British Vessels

Honan Maru (ex-War Sirdar)
(posted 1/1/2014)
Nansei Maru (ex-Pleiodon)
(posted 2/1/2014)
Shosei Maru (ex-Solen)
(posted 3/1/2014)

Ex-Dutch Vessels

Arare Maru (ex-Paula)
(revised 5/1/2014)
Bukun Maru (ex-Anastasia)
(posted 5/1/2014)
Gyoryu Maru (ex-Sumatra)
(posted 7/1/2016)
Kikusui Maru (ex-Iris)
(posted 7/1/2016)
Yuno Maru (ex-Juno)
(posted 7/1/2016)


Bibliography of Sources

About the Authors

Bob Hackett is a military historian and researcher. Retired from the United States Air Force and later from the aerospace industry, he resides in the United States.

Erich Muethlhaler is a maritime historian and researcher He resides in Germany.

Peter Cundall is a maritime historian and researcher who specializes in merchant ships. He resides in Australia.

Gilbert Casse is a maritime historian and researcher. Retired from aerospace industry and later from managing Le Mans racing cars and drivers. He resides on the SW coast of France.

Questions to the authors concerning these TROMs should be posted on the Discussion and Questions board.