RIKUGUN BOKU KIKANSEN

Stories and Battle Histories of Selected Imperial Army Anti-Aircraft Transports

3 July 2017

By Bob Hackett
with Erich Muehlthaler and Gilbert Casse

(ARIZONA MARU by Ueda Kihachiro)

By the end of 1941, Allied aircraft were considered a major threat to Japanese shipping, so to provide more protection for their invasion convoys, the IJA fitted some transports with additional anti-aircraft guns. These ships were officially called Boku Kikansen (anti-aircraft ships), but were commonly known as Bokusen. Each ship was armed with Army guns, generally consisting of six IJA Type-88 75-mm AA guns and six to ten IJA Type-98 20-mm AA machine-cannons.

Bokusen played an important role in the first phase invasions providing escort for the troop transports. However, in 1942, all transports were gradually fitted with additional AA guns. All Bokusen reverted to their original wartime tasks.

One IJA Bokusen has already been covered on our Tetsusei Dai Hatsudotei Landing Craft Depot Ships page (SHINSHU MARU). This page will cover the other seven Bokusen.

Tabular Records of Movement:
Rikugun Bokusen -Auxiliary Anti-Aircraft transports
(Classes link to specifications summaries)

ZENYO
MARU
Class

Zenyo Maru
(revised 7/3/2017)
SAKITO
MARU
Class

Sakura Maru
(revised 10/29/2011)
Sado Maru
(revised 1/1/2014)
YASUKAWA
MARU
Class

Yasukawa
Maru
(posted 4/6/2012)
KAMIKAWA
MARU
Class

Hirokawa Maru
(posted 9/1/2012)
ASOSAN
MARU
Class

Aobasan Maru
(posted 2/4/2012)
Atsutasan Maru
(posted 10/6/2012)
HAWAII
MARU
Class

Arizona Maru
(revised 4/1/2016)



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 on the coast of Florida.

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

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

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

Discussion & Questions