Stories and Battle Histories of the IJN's Minesweepers

19 October 2018

By Bob Hackett and Peter Cundall

Discussion & Questions

(W-19 Class Minesweeper by Takeshi Yuki)

The first class of IJN minesweepers was ordered in 1922. They were capable of functioning either as minesweepers or escorts. The IJN ordered 35 purpose-built minesweepers, most of them during the prewar years. During the war, two British minesweepers were captured in the builderís yard at Hong Kong and seven partially completed Dutch minesweepers were captured in Java. In addition to the IJNís regular minesweepers, well over 100 merchant ships were converted to auxiliary minesweepers.

In 1943-1944, to combat the growing onslaught of Allied submarines, the IJNís fleet of minesweepers was largely converted to convoy escorts. Their minesweeping gear was removed to enable them to carry up to 36 depth charges. Some classes had one or more of their main 4.7-inch guns removed and replaced by 25-mm Type 96 AA guns.

The size and complexity of the American mining offensive overwhelmed the IJN's meager and neglected minesweeping forces. The IJN's minesweeping equipment was technologically obsolete and their operations were wholly inadequate to the task. In the Spring of 1945, when the USAAF B-29 mining campaign began in earnest, the IJN was forced to withdraw some of its subchasers from vital convoy escort duties and convert them to minesweepers.

This page covers the activities of 35 of the Imperial Navy's purpose-built minesweepers and two British Royal Navy minesweepers captured at Hong Kong while under construction.

Tabular Records of Movement (TROMs):


(Minesweeper Classes link to specifications summaries)

W-1 Class

W-1 (revised 3/23/2018)

W-2(revised 10/20/2017)
W-3(revised 10/20/2017)
W-4 (revised 10/20/2017)

W-5 Class

W-5 (revised 10/20/2017)

W-6(revised 3/15/2013)

W-7 Class

W-7(revised 3/23/2018)

W-8 (revised 10/20/2017)
W-9 (revised 10/27/2017)
W-10 (revised 3/23/2018)
W-11 (revised 6/23/2018)
W-12 (revised 3/27/2018)

W-13 Class

W-13 (posted 9/23/2006)

W-14 (posted 9/5/2009)
W-15 (revised 3/23/2018)
W-16 (revised 3/23/2018)

W-17 Class

W-17 (revised 3/30/2018)

W-18 (revised 11/15/2015)

W-19 Class

W-19 (posted 9/23/2006)

W-20 (revised 3/30/2018)
W-21 (revised 6/23/2018)
W-22 (revised 3/30/2018)
W-23 (revised 3/30/2018)
W-24 (revised 10/19/2018)
W-25 (revised 1/15/2017)
W-26 (revised 3/1/2016)
W-27(revised 4/12/2015)
W-28 (revised 3/30/2018)
W-29 (revised 11/3/2017)
W-30(revised 11/22/2015)
W-33(revised 11/3/2017)
W-34(revised 3/30/2018)
W-38(revised 11/3/2017)
W-39(revised 11/3/2017)
W-41(revised 11/3/2017)

W-101 Class

W-101 (revised 11/3/2017)

W-102 (revised 4/19/2015)

Bibliography of Sources

About the Authors

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

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

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