Image of cover.

[Declassified] Confidential
4 June 1945




Japanese Naval Shipbuilding

"Know Your Enemy!"






CinCPac-CinCPOA Bulletin 142-45












Contents

JAPANESE NAVAL SHIPBUILDING Page 1
MAJOR WARSHIPS 2
SHIPBUILDING CENTERS 3
DESTROYERS 4
SUBMARINES 6
ESCORT VESSELS 8
MTBs 10
MINECRAFT 12
AUXILIARIES 14
SHIPYARDS
Carriers 15
Cruisers 15
Destroyers 16
Submarines 18
Minelayers and Minesweepers 20
Auxiliaries 22
Escort Craft 24
MTBs 32

JICPOA-L 50530-I thru 35


Japanese Naval Shipbuilding

Information from official sources is now available on the details of Japanese Naval shipbuilding from early 1941 almost to the end of 1944. Captured documents had previously provided a complete list of official Navy announcements of new construction and conversions (TATSU) from 5 February 1941 to 10 May 1944. Additional documents, captured on Iwo Jima, have carried the list as far as 25 October 1944.

These TATSU are believed to be authentic and practically all-inclusive. Of the warships definitely known, from other sources, to have been built or converted during this period, only the converted CVLs Ryuho, Chitose. and Chiyoda. fail to appear on this list. Their omission is unexplained.

In the following pages the contents of these TATSU are presented, arranged by type and by the shipyards which did the construction. They are also presented graphically according to type and date of construction. Three salient points emerge from this analysis:

(1) Construction of fleet units has concentrated overwhelmingly on carriers, with a notable deficiency of both heavy surface units and fleet type destroyers.

(2) Beginning in 1943, a tremendous proportion of warship construction has been devoted to escort vessels.

(3) Major shipbuilding has been carried on entirely in the home islands, with the bulk of it concentrated in a few shipyards in the great industrial areas of Japan.

In referring to the TATSU it is important to remember that the date of announcement simply indicates that the ship was under construction at that time. There is no fixed correlation between this date and the date of completion. A destroyer ordinarily is in service within two or three months of its announcement. With larger ships the time lag is greater, and with smaller ships it is less.

For purposes of graphic presentation the rate of construction for the last two months of 1944 has been estimated wherever practical.

This supplement comprises an enlargement and revision of an article on Japanese Naval Shipbuilding which appeared in CINCPAC-CINCPOA Weekly Intelligence, Vol, 1, No. 13, 6 October 1944. Except as specifically noted it is based entirely on the TATSU.

--1--

Major Warships

The building program for major warships from 1941 to 1944 shows an overwhelming emphasis on carrier construction. During this period the Jap Navy announced:

(1) Eight large carriers either built as carriers from the keel up or converted from warship hulls at an early stage.

(2) Two large carriers converted from luxury liners.

(3) One CVL converted from a submarine tender.

(4) Five CVEs converted from large passenger ships.

In addition, Ryuho, Chitose and Chiyoda are believed to have been converted to CVLs during this period, although no announcement of such conversion was issued.

No battleships were announced as building during this period. The Yamato had previously been announced on 25 July, 1940. The date of Musashi's announcement is not known.

Only one heavy cruiser, the Ibuki, appears in this list. There has been some indication that even this ship was finished as a CVL rather than a CA.

Five light cruisers have been completed during the war. Agano, Noshiro, Yahagi and Sakawa belong to the Agano class. Oyodo forms a separate class. These ships have been used chiefly as DesRon flagships. All of Japan's pre-war light cruisers were small, lightly armed, and particularly deficient in AA defense. New construction has been on a scale inadequate to replace those obsolescent vessels.

In short, Japan's wartime building program has been lopsided. By concentrating on carriers she achieved what was once a formidable carrier force. At the same time, however, she failed to achieve a balanced fleet. Her carrier forces have never been backed by a large group of fast modern battleships, and her light screening forces have become fewer and fewer.

--2--

Map - Shipbuilding Centers in Japan.
Shipbuilding Centers in Japan.

--3--

Destroyers

It is reliably estimated that from the start of the war until the end of 1943 the enemy lost approximately 55 destroyers. During this period planned construction as reflected in official announcements totalled only 23 units. No significant increase in the rate of construction appeared, even in comparison with the pre-war 1941 rate.

To close this ruinous gap between loss and construction, the Japs resorted to building 1000-ton Matsu Class ships at the expense of fleet destroyers. During 1944 they announced an estimated 26 destroyers, 21 of the Matsu Class and only 5 of them fleet types. Even this effort failed signally to preserve the destroyer force, as the rate of loss doubled simultaneously. At least 55 destroyers are thought to have been sunk during 1944.

DD SHIMAKAZE - off Leyte 11 November 1944.
DD Shimakaze - off Leyte 11 November 1944.

--4--

Destroyer Construction, 1941-1944

Note: Construction for last two months of 1944 estimated from previous rate.


1941 1st Half Total DDs (4)

1941 2nd Half Total DDs (5)

1942 1st Half Total DDs (7)

1942 2nd Half Total DDs (4)

1943 1st Half Total DDs (6)

1943 2nd Half Total DDs (5)

_Matsu DD (1)
1944 1st Half Total DDs (14)

____________Matsu DDs (12)
1944 2nd Half Total DDs (12)

_________ Matsu DDs (9)

--5--

Submarines

The rate of Japanese submarine construction has remained uniformly high. From 1941 through 1944 the enemy announced new construction of an estimated 114 submarines — exactly twice the number of destroyers announced in the same period.

Emphasis on type has shifted considerably. About half of the four-year total consists of large I-Class ships. During 1942 and 1943 nearly half of the subs built belonged to the medium RO-Class. During 1944, however, only one RO-Class ship was built. Instead, the new, small HA-Class subs were announced in considerable numbers.

SS RO-54 of RO-51 Class.
SS RO-54 of RO-51 Class.

--6--

Submarine Construction, 1941-1944

Note: Construction for last two months of 1944 estimated from previous rate.

1941 1st Half Total SS (3)
I-Class (3)

1941 2nd Half Total SS (11)
-------- I-Class (8)
--- RO-Class (3)

1942 1st Half Total SS (16)
-------- I-Class (8)
-------- RO-Class (8)

1942 2nd Half Total SS (18)
--------- I-Class (9)
--------- RO-Class (9)

1943 1st Half Total SS (15)
----- I-Class (5)
---------- RO-Class (10)

1943 2nd Half Total SS (20)
--------------- I-Class (15)
----- RO-Class (5)

1944 1st Half Total SS (12)
--------- I-Class (9)
- RO-Class (1)
-- HA-Class (2)

1944 2nd Half Total SS (19)
-------- I-Class (8)
-----------HA-Class (11)

--7--

Escort Vessels

The escort vessel program absorbed a tremendous proportion of Japan's total building effort during 1943 and 1944. This concentration on building escort types, necessitated by the success of our submarine warfare, was a major factor in the decline of the Japanese Navy. At a time when they were losing two destroyers for every one they were building, the Japanese were forced to give highest priority to the construction of subchasers and KAIBOKAN. By October 1944 the screening forces of the Japanese fleet had become seriously inadequate.

A notable feature of the escort building program was the shift of emphasis from the short-range subchaser and special subchaser types to the larger escorts (KAIBOKAN). Originally the Japanese depended largely on destroyers for long-range convoy escort. This practice proved costly and ineffective. The various classes of KAIBOKAN were designed to provide deep-water protection for medium and high speed convoys.

KAIBOKAN at Ormoc Bay 10 November 1944.
KAIBOKAN at Ormoc Bay 10 November 1944.

--8--

Anti-Submarine Vessel Construction, 1941-1944

Note: Construction for last two months of 1944 estimated from previous rate.

1941 1st Half Total AS Ships (7)
------- SC and SSC (7)

1941 2nd Half Total AS Ships (7)
------- SC and SSC (7)

1942 1st Half Total AS Ships (8)
-------- SC and SSC (8)

1942 2nd Half Total AS Ships (42)
------------------------------------ SC and SSC (36)
------ Escorts (KAIBOKAN) (6)

1943 1st Half Total AS Ships (26)
-------------------- SC and SSC (20)
------ Escorts (KAIBOKAN) (6)

1943 2nd Half Total AS Ships (93)
--------------------------------------------------------------- SC and SSC (63)
------------------------------ Escorts (KAIBOKAN) (30)

1944 1st Half Total AS Ships (86)
--------------------------------------------------- SC and SSC (51)
----------------------------------- Escorts (KAIBOKAN) (35)

1944 2nd Half Total AS Ships (132)
------------------------------------------------------ SC and SSC (54)
------------------------------------------------------------------------------ Escorts (KAIBOKAN) (78)

--9--

MTBs

The original classes of Japanese MTB laid down in 1941 were experimental and evidently unsuccessful. All but one of these boats have been scratched from the Navy list. Construction of MTB was suspended during 1942. However, the enemy was evidently impressed by the success of American PT boats. In the latter half of 1943 he began an ambitious building program for this type, and by the end of 1944 had laid down nearly 600 boats.

Japanese MTB have seen little action in the war. Presumably large numbers of them are being held in the Empire for suicidal defense against invasion.

HAYABUSA boats are similar to MTB, but carry more guns in place of torpedoes. For a discussion of Jap MTB types, see "Weekly Intelligence", Vol. 1, No. 13.

Jap PT boats.
Jap PT boats.

--10--

MTB and Hayabusa Boat Construction, 1941-1944

Note: Construction for last two months of 1944 estimated from previous rate.

1941 1st Half --- (3)

1941 2nd Half --- (3)

1942 1st Half (0)

1942 2nd Half (0)

1943 1st Half - (1)

1943 2nd Half -------------------- ... --------------------------- (237)

1944 1st Half -------------------- ... --------------- (165)

1944 2nd Half -------------------- ... --------------- (165)

--11--

Minecraft

It is notable that the Japanese building program for minecraft fell off to nothing during 1944. Presumably U.S. submarine successes made the need for escort craft so pressing that more specialized types suffered. Actually, most escort types can be converted to minesweeping with little effort, so that the enemy's potential defense against mines may have suffered less than it would appear. Similarly, merchant ships and large escorts can be used as minelayers with little alteration. There is evidence that in actual practice the Japanese have used their minecraft and escort vessels interchangeably.

SOKUTEN Class CMc.  Captured film.
Sokuten Class CMc. Captured film.

--12--

Construction of Japanese Minecraft (Minelayers and Minesweepers), 1941-1944

1941 1st Half Total Minecraft (4)

1941 2nd Half Total Minecraft (6)

1942 1st Half Total Minecraft (11)

1942 2nd Half Total Minecraft (18)

1943 1st Half Total Minecraft (11)

1943 2nd Half Total Minecraft (4)

1944 1st Half Total Minecraft (3)

1944 2nd Half Total Minecraft (0)

--13--

Auxiliaries

During 1944 the Japanese announced an estimated 20 APD and 45 LSM. (Dates of announcement of the LSM are not given, but they were probably all announced during 1944. Construction of both APD and LSM for the last two months of 1944 have been estimated from the prior rate of building.) These two types were designed to fill the need for small, moderately fast transports to operate in dangerous waters. Prior to our occupation of Iwo Jima, APD were frequently observed on transport runs to that island. These types have eased the burden on Jap destroyers, which were formerly depended on for fast operational transport.

Details are not in all cases available, but it is thought that the great majority of miscellaneous named auxiliaries which appear in the list are fleet oilers.

Japanese Numbered Naval Transport.
Japanese Numbered Naval Transport.

--14--

Shipyards Building Carriers

There is no announcement of the Ryuho, first believed operational in 1942, or of Chitose and Chiyoda, believed to have been converted during 1943.

Yard Location Date of
Announcement
Ship
Kawasaki Heavy
  Industries Ltd
Kobe 5 Mar. 1943
5 Sept 1944
(CV) Taiho
(CV) Ikoma
 
Kure Navy Yard Kure 20 Aug. 1942
15 Dec. 1943
22 Dec. 1943
5 Sept 1944
(CVE) Chuyo (Converted from Nitta Maru)
(CVE) Shinyo (Converted from Scharnhorst)
(CV) Katsuragi
(CV) Aso
 
Mitsubishi Heavy
  Industries Ltd,
  Nagasaki Shipyard
Nagasaki 23 Sept 1943

25 Sept 1943
5 Sept 1944
(CVE) Kaiyo (Converted from Argentina Maru)

(CV) Amagi
(CV) Kasagi
 
Yokosuka Navy Yard Yokosuka 31 July 1943
1 July 1944
(CV) Unryu
(CV)Shinano
 
Not given   22 Dec. 1941
1 July 1942
31 July 1942
31 Aug. 1942
31 Aug. 1942
(CVL) Shoho (Converted from AS Tsurigizaki)
(CV) Junyo (Converted from Kashiwara Maru)
(CV) Hiyo (Convered from Izumo Maru)
(CVE) Taiyo (Converted from Kasuga Maru)
(CVE) Unyo (Converted from Yawata Maru)
 
Shipyards Building Cruisers
 
Kure Navy Yard Kure 10 Mar. 1942
5 Apr. 1943
(CL) Oyodo
(CA) Ibuki
Sasebo Navy Yard Sasebo 20 Sept 1941
20 Sept 1942
1 Apr. 1944
(CL) Agano
(CL) Yahagi
(CL) Sakawa
 
Yokosuka Navy Yard Yokosuka 15 May 1942 (CL) Noshiro

--15--

Shipyards Building Destroyers

Yard Location Date of
Announcement
Ship
Fujinagata Shipbuilding
Works Ltd
Osaka 5 Feb. 1941
5 Aug. 1941
17 Dec. 1942
20 June 1942
1 Nov. 1942
5 Mar. 1943
25 May 1943
31 Aug. 1943
25 Jan. 1944
5 Apr. 1944
June 1944
23 June 1944
25 Aug. 1944
25 Aug. 1944
Maikaze
Makigumo
Naganami
Onami
Tamanami
Fujinami
Asashimo
Akishimo
Ume
Kuwa
Sugi
Kashi
Nara
Yanagi
 
Maizuru Navy Yard Maizuru 5 Feb. 1941
15 May 1941
25 Oct. 1941
1 Mar. 1942
15 May 1942
10 July 1942
25 Sept 1942
25 May 1943
31 July 1943
1 Oct. 1943
22 Dec. 1943
25 Jan. 1944
June 1944
23 June 1944
25 Aug. 1944
25 Aug. 1944
Yugumo
Akitsuki
Makinami
Hatsuzuki
Shimakaze
Hayanami
Hamanami
Okinami
Hayashimo
Fuyuzuki
Matsu
Momo
Maki
Kaya
Hanazuki
Tsubaki
 
Mitsubishi Heavy
Industries Ltd,
Nagasaki Shipyard
Nagasaki 25 Oct. 1941
20 Jan. 1942
15 May 1942
20 Aug. 1942
5 Mar. 1943
Terutsuki
Suzutsuki
Niizuki
Wakatsuki
Shimotsuki
 
Sasebo Navy Yard Sasebo 10 May 1944
5 Oct. 1944
Harutsuki
Natsuzuki
 
Uraga Dock Co Ltd,
Uraga Shipyard
Yokosuka Shi,
Uraga-Machi
25 Mar. 1941
10 Sept 1941
20 Jan. 1942
20 June 1942
5 Feb. 1943
25 May 1943
Akigumo
Kazagumo
Takanami
Kiyonami
Suzunami
Kishinami

--16--

Destroyers (Cont'd.)

Yard Location Date of
Announcement
Ship
Uraga Dock Co., Ltd, Uraga Shipyard Yokosuka Shi, Uraga-Machi 31 Aug. 1943
10 May 1944
Kiyoshimo
Yoizuki
 
Yokosuka Navy Yard Yokosuka 25 Jan. 1944
May 1944
June 1944
23 June 1944
25 Aug. 1944
1 Sept 1944
1 Sept 1944
5 Oct. 1944
Take
Kiri
Momi
Kaede, Hinoki
Sakura
Keyaki
Tachibana
Tsuta

 

 

--17--

Shipyards Building Submarines

Yard Location Date of
Announcement
Ship
Kawasaki Heavy Industries Ltd Kobe 5 Feb. 1941
17 Dec. 1941
20 Jan. 1942
8 Apr. 1942
15 May 1942
20 Aug. 1942
25 Sept 1942
25 Dec. 1942
5 Feb. 1943
5 Apr. 1943
5 July 1943
1 Oct. 1943
22 Dec. 1943
25 Jan. 1944
15 Mar. 1944
23 June 1944
25 Aug. 1944
25 Aug. 1944
5 Oct. 1944
I-11
I-177
RO-101, RO-102
I-179
RO-104, RO-105
RO-109
I-183, RO-108
RO-110, RO-111
RO-112, RO-113
RO-114, RO-115
I-12, RO-116, RO-117
I-13
I-14
I-15
I-1
HA-101, HA-102
I-405
HA-103, HA-105
HA-108, HA-110
 
Kure Navy Yard Kure 15 May 1941
10 Sept 1941
25 Nov. 1941
22 Dec. 1941
8 Apr. 1942
20 Aug. 1942
1 Nov. 1942
20 Oct. 1943
22 Dec. 1943
5 Apr. 1944
23 June 1944
25 Aug. 1944
1 Sept 1944
5 Oct. 1944
I-76
I-49
RO-100, RO-103
I-351, I-400
I-181, RO-106, RO-107
I-40, I-41, I-42, I-52
I-53, I-55
I-361, I-363
I-351, I-400
I-352
I-201
I-202, I-203
I-204
I-205
 
Mitsubishi Heavy Industries Ltd, Kobe Shipyard Kobe 25 Mar. 1941
10 Sept 1941
22 Dec. 1941
20 Jan. 1942
15 May 1942
25 Sept 1942
1 Nov. 1942
25 Dec. 1942
5 Feb. 1943
5 Mar. 1943
25 May 1943
31 July 1943
I-41
I-45
I-366
I-178
RO-35
RO-36
RO-38
RO-39
RO-40
RO-41, RO-43
RO-45, RO-47
RO-48

--18--

Submarines (Cont'd.)

Yard Location Date of
Announcement
Ship
Mitsubishi Heavy Industries Ltd, Kobe Shipyard Kobe 20 Oct. 1943
22 Dec. 1943
5 Apr. 1944
10 May 1944
25 Aug. 1944
1 Sept 1944
I-362, I-364
I-366
I-367
I-370, I-371
HA-104, HA-106
HA-107, HA-109
 
Mitsui Shipbuilding Ltd, Tamano Yard Okayama Ken, Tamano Shi 22 Dec. 1941
1 Nov. 1942
5 Feb. 1943
31 July 1943
1 Oct. 1943
10 May 1943
RO-55
FO-44
RO-46
RO-49
RO-50
RO-56
 
Sasebo Navy Yard Sasebo 5 Aug. 1941
8 Apr. 1942
20 June 1942
25 Sept 1942
5 Feb. 1943
25 May 1943
31 July 1943
22 Dec. 1943
I-43
I-38, I-39
RO-37
I-43, RO-42
I-45
I-46
I-47
I-48, I-401
 
Yokosuka Navy Yard Yokosuka 25 Oct. 1941
20 Jan. 1942
8 Apr. 1942
20 June 1942
25 Sept 1942
5 Feb. 1943
5 Apr. 1943
No date
31 July 1943
20 Oct. 1943
25 Jan. 1944
5 Oct. 1944
I-47
I-180
I-182
I-185
I-184
I-44
I-54
I-56
I-58
I-365
I-368, I-369
I-373

--19--

Shipyards Building Minelayers and Minesweepers

Yard Location Date of
Announcement
Ship
Fujinagata Shipbuilding Works Ltd Osaka 1 Oct. 1943 AM's #38, #41
 
Harima Shipbuilding Co Ltd Hyogo Ken, O Shi 15 May 1941
20 Jan. 1942
20 June 1942
5 Feb. 1943
24 Feb. 1944
CM Wakataka
AM #21
AM #24
AM #27
AM #39
 
Hidachi Shipbuilding Co Ltd, Innoshima Yard Hiroshima Ken, Mitsugi Gun 15 Mar. 1944 CMc Ajiro
 
Ishikawajima Shipbuilding Co Ltd Tokyo 5 Aug. 1941
1 Mar. 1942
20 Aug. 1942
5 Apr. 1943
31 Aug. 1943
25 Jan. 1944
AM #20
AM #22
AM #23
AM #29
AM #30
AM #34
 
Japan Steel Tubing Co, Tsurummi Shipyard Yokohama 30 June 1941
8 Apr. 1942
5 Feb. 1943
CMc Takashima
CMc Yurijima
CMc Maejima
 
Kure Navy Yard Kure 10 July 1942
25 Dec. 1942
AM #25
AM #28
 
Mitsubishi Heavy Indistries Ltd, Hikoshima Shipyard Yamaguchi Ken, Hikoshima 10 July 1942
1 Nov. 1942
5 Mar. 1943
Sp CM's #7, #8
Sp AM's #13, #14
Sp AM #21
 
Mitsubishi Heavy Industries Ltd, Yokohama Dock Yokohama 30 June 1941
20 Aug. 1942
5 Apr. 1943
CMc Ishizaki
AM #26
AM #33
 
Mitsui Shipbuilding Co Ltd, Tamano Yard Okayama Ken, Tamano Shi 5 Aug. 1941
20 Jan. 1942
CMc Hoko
CMc Niizaki
 
Namura Shipyard Co Osaka 10 July 1942
1 Nov. 1942
5 Apr. 1943
5 July 1943
Sp AM #9
Sp AM #15
Sp AM #18
Sp AM #22
 
Naniwa Dock Co Ltd Osaka 20 Jan. 1942
15 May 1942
10 July 1942
1 Nov. 1942
5 Apr. 1943
Sp CM #4
Sp CM #6
Sm AM #11
Sm AM's #12, #17
Sp AM #20

--20--

Minelayers and Minesweepers (Cont'd.)

Yard Location Date of
Announcement
Ship
102nd Naval C&R Department, Batavia Branch Batavia, Java 5 Dec. 1942 Sp AM's #101, #102, #103
(converted from incompleted captured NETHERLANDS AMs)
    1 Apr. 1943 Sp AM #105
(converted from incompleted captured NETHERLANDS AM)
 
2nd Naval C&R Department Hongkong 1 Apr. 1943 AM's #101, #102
(converted from captured incompleted BRITISH AMs)
 
Osaka Iron Works Ltd. Osaka 30 June 1941
10 Sept. 1941
20 Jan. 1942
8 Apr. 1942
CMc Saishu
SP AM's #1, #2
Sp CM's #3, #5
CMc Nuwajima
 
Sanoyasu Dock Co. Osaka 10 July 1942
1 Nov. 1942
5 Mar. 1943
Sp AM #10
Sp AM #16
Sp AM #19
 
Uraga Dock Co Ltd, Uraga Shipyard Yokosuka Shi, Uraga-Machi 10 Sept. 1941
17 Dec. 1941
20 Jan. 1942
CMC's #1, #2
CMc #3
CMc #4

--21--

Shipyards Building Auxiliaries

Yard Location Date of
Announcement
Ship
Harima Shipbuilding Co Ltd. Hyogo Ken, O Shi 25 Sept. 1942
25 May 1943
31 July 1943
1 Sept. 1944
Auxiliary Kazahaya (AO)
Auxiliary Hakachi
Auxiliary Hayasui
Auxilary Hario
 
Hidachi Shipbuilding Works Ltd, Mukojima Shipyard Tokyo Not given LSM #149
LSM #151
LSM #152
LSM #153
LSM #154
LSM #157
LSM #158
LSM #159
LSM #160
LSM #161
 
Kawanami Industries Ltd, Urasaki Shipyard Kagoshima Ken, Urasaki Not given LSM #127
LSM #129
LSM #131
LSM #132
LSM #134
LSM #135
LSM #136
LSM #137
LSM #138
LSM #139
LSM #142
LSM #143
LSM #144
 
Kawasaki Heavy Industries Ltd. Kobe 5 Feb. 1941
30 June 1941
Auxiliary Irako
AS Akitsushima
 
Kure Navy Yard Kure 15 Mar. 1944
10 May 1944
10 July 1944
25 Aug. 1944
5 Oct. 1944
APD's #3, #4
APD's #5, #6
APD's #9, #10
APD's #11, #12
APD's #14, #15
 
Mitsubishi Heavy Industries Ltd, Yokohama Dock Yokohama 25 Sept. 1942
25 Dec. 1942
25 Jan. 1944
5 Feb. 1944
15 Mar. 1944
10 May 1944
 
1 Sept. 1944
Auxiliary Sunosaki
Auxiliary Takasaki
Auxiliary Ohama
APD #1
APD #2
APD #7
AG (Target) Osashi
APD's #13, #16

--22--

Auxiliaries (Cont'd.)
Yard Location Date of
Announcement
Ship
Mitsubishi Heavy Industries Ltd, Nagasaki Shipyard Nagasaki 1 Mar. 1942
25 Dec. 1942
Auxiliary Ashizuri
Auxiliary Shioya
 
Osaka Iron Works Ltd. Osaka 8 Apr. 1942
20 Aug. 1942
5 Feb. 1943
Auxiliary Hayasaki
Auxiliary Shirasaki
Auxiliary Arasaki
 
Osaka Shipbuilding Works Ltd. Osaka Not given LSM #101
LSM #102
LSM #104
LSM #105
LSM #106
LSM #107
LSM #108
LSM #110
LSM #111
LSM #112
LSM #113
LSM #114
LSM #115
 
Sasebo Navy Yard Sasebo Not given LSM #133
LSM #140
LSM #141
 
Not given   23 June 1944 APD #8

--23--

Shipyards Building Escort Craft

Yard Location Date of
Announcement
Ship
Fujinagata Shipbuilding Works Ltd. Osaka 25 Aug 1944 Escorts #48, #58
 
Fukuoka Shipbuilding & Iron Co. Fukuoka Ken, Fukuoka Shi 25 July 1942
30 Apr. 1943
1 July 1943
1 Oct. 1943
25 Jan. 1944
5 Apr. 1944
10 June 1944
10 July 1944
28 Aug. 1944
Sp SC #13
Sp SC #39
Sp SC #56
Sp SC #75
Sp SC #154
Sp SC #173
Sp SC #207
Sp SC #224
Sp SC #243
 
Fukushima Shipbuilding & Iron Works Ltd. Fukushima 25 July 1942
25 Dec. 1942
30 Apr. 1943
1 July 1943
1 Oct. 1943
1 Dec. 1943
25 Jan. 1944
5 Apr. 1944
10 June 1944
10 July 1944
30 Sept. 1944
Sp SC #15
Sp SC #21
Sp SC #40
Sp SC #48
Sp SC's #67, #76
Sp SC #93
Sp SC #157
Sp SC #166
Sp SC #199
Sp SC #222
Sp SC #249
 
Funaya Shipbuilding & Iron Works Ltd. [Hiroshima]? 25 Dec. 1942
1 July 1943
25 Aug. 1943
1 Dec. 1943
10 June 1944
28 Aug. 1944
Sp SC #29
Sp SC #49
Sp SC #81
Sp SC #91
Sp SC #203
Sp SC #237
 
Hakodate Dock Co. Muroran Yard Hokkaido, Muroran 15 May 1942
5 Mar. 1943
5 July 1943
1 Oct. 1943
15 Mar. 1944
SC #35
SC #45
SC #49
SC #55
SC #57
 
Harima Shipbuilding Co Ltd. Hyogo Ken, O Shi 30 June 1941
25 Oct. 1941
15 May 1942
?      
10 May 1944
SC #23
SC #29
SC #39
Escort Ihojima
Escort #130

--24--

Escort Craft (Cont'd.)

Yard Location Date of
Announcement
Ship
Harima Shipbuilding Co Ltd. Hyogo Ken, O Shi 23 June 1944
25 Aug. 1944
1 Sept. 1944
5 Oct. 1944
Escort #132
Escort #138
Escort #150
Escort #144
 
Hatyashigane Co, Hikoshima Iron Works Yamaguchi Ken, Hikoshima 25 July 1942
30 Apr. 1943
1 July 1943
25 Aug. 1943
1 Oct. 1943
1 Dec. 1943
25 Jan. 1944
5 Apr. 1944
10 June 1944
10 July 1944
28 Aug. 1944
30 Sept. 1944
Sp SC #5
Sp SC's #33, #38
Sp SC #51
Sp SC's #62, #66, #74
Sp SC #83
Sp SC's #87, #99
Sp SC #160
Sp SC #167
Sp SC's #200, #201
Sp SC #216
Sp SC's #228, #235
Sp SC #250
 
Hidachi Shipbuilding Co Ltd, Sakurajima Shipyard Osaka 25 May 1943
31 July 1943
31 Aug. 1943
22 Dec. 1943
25 Jan. 1944
10 May 1944
25 Aug. 1944
1 Sept. 1944
5 Oct. 1944
Escort Hirato, SC #46
Escort Amakusa
Escort Awaji
Escort Nomi
Escorts Yashiro and Hiburi
Escort Shonan
Escort Kume
Escorts Ikuna and Shisaka
Escort Sakito
 
Hidachi Shipbuilding Co Ltd, Inno Shima Yard Hiroshima Ken, Mitsugi Gun 31 July 1943 SC #50
 
Ichikawa Shipbuilding Co Ltd. Mie Ken, Ominato 25 July 1942
25 Dec. 1942
30 Apr. 1943
1 July 1943
25 Aug. 1943
1 Dec. 1943
5 Apr. 1944
10 June 1944
10 July 1944
28 Aug. 1944
30 Sept 1944
Sp SC's #1, #4, #9
Sp SC #22
Sp SC's #34, #45
Sp SC #55
Sp SC #69
Sp SC's #79, #96
Sp SC's #164, #176
Sp SC's #197, #213
Sp SC #220
Sp SC #232
Sp SC #247

--25--

Escort Craft (Cont'd.)

Yard Location Date of
Announcement
Ship
Ishikawajima Shipbuilding Co Ltd. Tokyo 5 Feb. 1941
10 Sept. 1941
1 Mar. 1942
15 May 1942
22 Dec. 1943
10 May 1944
25 Aug. 1944
1 Sept 1944
5 Oct. 1944
SC #17
SC #27
SC #31
SC #36
Escorts #5, #7
Escort #34
Escort #50
Escort #72
Escort #106
 
Japan Sea Dock Co. Toyama Ken, Toyama Shi 15 Mar. 1944
5 Apr. 1944
10 May 1944
25 Aug. 1944
5 Oct. 1944
Escort #21
Escort #23
Escort #37
Escort #45
Escort #65
 
Japan Steel Tubing Co, Tsurumi Shipyard Yokohama 21 Mar. 1941
30 June 1941
17 Dec. 1941
8 Apr. 1942
15 May 1942
20 Aug. 1942
1 Nov. 1942
25 May 1943
5 July 1943
31 Aug. 1943
 
1 Oct. 1943
22 Dec. 1943
25 Jan. 1944
15 Mar. 1944
5 Apr. 1944
10 May 1944
23 June 1944
25 Aug. 1944
1 Sept 1944
5 Oct. 1944
SC #18
SC #26
SC #28
SC #32
SC #38
Escort Sado
Escort Tsushima
Escort Mikura
Escort Miyake
Escort Kurabashi
Escort Chiburi
Escort Kusagaki
Escorts #5, #7
Escorts Ukuru, #13, #15, #17, #19
Escort Okinawa
Escorts Amami, Aguni, #25, #27
Escorts #29, #31
Escort #35
Escorts #41, #47, #49
Escorts #53, #55
Escorts #57, #59
 
Jinen Shipbuilding & Iron Works Ltd. Mie Ken, Ominato 25 July 1942
25 Dec. 1942
30 Apr. 1943
1 July 1943
25 Aug. 1943
1 Dec. 1943
25 Jan. 1944
Sp SC #12
Sp SC #24
Sp SC #42
Sp SC #52
Sp SC #63
Sp SC #90
Sp SC #158

--26--

Escort Craft (Cont'd.)

Yard Location Date of
Announcement
Ship
Jinen Shipbuilding & Iron Works Contd. Mie Ken, Ominato 5 Apr. 1944
10 June 1944
10 July 1944
28 Aug. 1944
Sp SC #169
Sp SC #205
Sp SC #223
Sp SC #239
 
Kawaminami Industries Ltd, Koyagishima Shipyard Nagasaki 10 July 1942
25 Dec. 1942
25 May 1943
31 July 1943
SC #41
SC #44
SC #47
SC #51
 
Kawasaki Heavy Industries Ltd. Kobe 5 June 1944
5 June 1944
23 June 1944
25 Aug. 1944
Escort #38
Escort #46
Escort #56
Escorts #60, #68, #118, #124
 
Kawasaki Heavy Industries Ltd, Senshu Branch Works Osaka 7 Aug. 1944 Escort #112
 
Koyanagi Shipyard Co. ? 25 July 1942
25 Dec. 1942
20 Apr. 1943
1 July 1943
1 Oct. 1943
1 Dec. 1943
5 Apr. 1944
10 June 1944
10 July 1944
28 Aug. 1944
Sp SC #14
Sp SC #27
Sp SC #44
Sp SC #58
Sp SC #77
Sp SC #94
Sp SC #171
Sp SC #209
Sp SC #225
Sp SC #241
 
Kyoryoku Shipyard Mie Ken, Ominato 25 July 1942
25 Dec. 1942
30 Apr. 1943
1 July 1943
1 Oct. 1943
25 Jan. 1944
10 June 1944
28 Aug. 1944
Sp SC #7
Sp SC #17
Sp SC #37
Sp SC #54
Sp SC's #73, #98
Sp SC #161
Sp SC #206
Sp SC's #226, #245
 
Kyowa Shipbuilding Co. Ltd. ? 25 Aug. 1944 Escorts #83, #93
 
Maizuru Navy Yard Maizuru 25 Aug. 1944
1 Sept 1944
Escort #67
Escort #81

--27--

Escort Craft (Cont'd.)
Yard Location Date of
Announcement
Ship
Mio Shipyard Co. Shizuoka Ken, Shimizu Shi 25 Dec. 1942
30 Apr. 1943
1 July 1943
31 July 1943
1 Dec. 1943
5 Apr. 1944
10 June 1944
10 July 1944
28 Aug. 1944
Sp SC's #19, #26
Sp SC #43
Sp SC #57
Sp SC #68
Sp SC's #84, #95
Sp SC #170
Sp SC #208
Sp SC #217
Sp SC's #229, #240
 
Mitsubishi Heavy Industries Ltd, Kobe Shipyard Kobe 22 Dec. 1943
10 May 1944
5 June 1944
25 Aug. 1944
1 Sept 1944
Escorts #1, #3, #9, #11
Escort #43
Escort #51
Escort #63
Escort #69
 
Mitsubishih Heavy Indistries, Ltd, Nagasaki Shipyard Nagasaki 22 Dec. 1943
5 Apr. 1944
10 May 1944
5 June 1944
7 Aug. 1944
25 Aug. 1944
1 Sept. 1944
5 Oct. 1944
Escorts #8, #10, #18, #20, #22, #24
Escorts #26, #28
Escorts #30, #32
Escorts #42, #44
Escorts, #52, #54
Escorts #64, #66
Escorts #74, #76
Escorts #82, #84, #102, #104
 
Mitsubishih Heavy Industries Ltd, Yokohama Dock Yokohama 25 Mar. 1941
10 Sept 1941
SC #22
SC #25
 
Mitsui Shipbuilding Co Ltd, Tamano Yard Okayama Ken, Tamano Shi 15 May 1941
8 Apr. 1942
15 May 1942
20 Aug. 1942
25 Dec. 1942
5 Apr. 1943
5 July 1943
1 Sept 1944
1 Sept 1944
5 Oct. 1944
SC #20
SC #33
SC #37
Escort Matsuwa
Escort Iki
Escort Wakamiya
Escort Manju
Escort Inagi
Escort Habushi
Escort Ojika
 
Murakami Shipyard Osaka 25 Dec. 1942
25 Aug. 1943
10 June 1944
28 Aug. 1944
Sp SC's #23, #30
Sp SC's #82, #88
Sp SC #202
Sp SC #236

--28--

Escort Craft (Cont'd.)
Yard Location Date of
Announcement
Ship
Naniwa Dock Co Ltd. Osaka 31 July 1943
15 Mar. 1944
25 Aug. 1944
5 Oct. 1944
SC's #52, #53
SC #56
Escort #207
Escort #219
 
102nd Naval C and R Department Soerabaja, Java 5 Dec. 1942 Sp SC's #105, #106, #107, #108 (converted from captured incomplete NETHERLANDS patrol boats.)
    1 Apr. 1943 Sp SC's #114, #115 (converted from captured incomplete NETHERLANDS patrol boats.)
    31 July 1944 Sp SC #118 (converted from captured NETHERLANDS SC)
 
Niigata Iron Works Ltd. Niigata Ken, Niigata Shi 31 July 1943
20 Aug. 1943
31 Aug. 1943
20 Oct. 1943
22 Dec. 1943
25 Jan. 1944
25 Aug. 1944
1 Sept 1944
SC #54
SC #43
SC #58
SC #60
SC #61
SC #63
Escort #205
Escort #215
 
Nishii Shipyard Mie Ken, Ominato 25 July 1942
25 Dec. 1942
30 Apr. 1943
1 July 1943
1 Oct. 1943
25 Jan. 1944
5 Apr. 1944
10 June 1944
28 Aug. 1944
Sp SC #6
Sp SC #16
Sp SC #36
Sp SC #53
Sp SC's #72, #97
Sp SC #159
Sp SC #174
Sp SC #211
Sp SC's #227, #224
 
Osaka Iron Works Ltd Hiroshima Ken, Mitsugi Gun 10 July 1942 SC #40
 
Osaka Iron Works Ltd Osaka 15 May 1941
5 Aug. 1941
20 Aug. 1942
5 Mar. 1943
SC #21
SC #24
Escorts Etorofu, SC #42
Escort Mutsure

--29--

Escort Craft (Cont'd.)

Yard Location Date of
Announcement
Ship
Saga Shipbuiloding and Iron Works Ltd Minato 25 July 1942
25 Dec. 1942
1 July 1943
25 Aug. 1943
1 Oct. 1943
25 Jan. 1944
5 Apr. 1944
10 June 1944
10 July 1944
28 Aug. 1944
Sp SC's #3, #10
Sp SC's #18, #28
Sp SC #46
Sp SC's #61, #71, #80
Sp SC #100
Sp SC's #153, #162
Sp SC #172
Sp SC #210
Sp SC #218
Sp SC's #230, #242
 
Sasebo Navy Yard Sasebo 1 Sept 1944 Escorts Uku and Kuga
 
Shikoku Docks Workships Ltd [Asahi-machi, Shikoku]? 25 July 1942
25 Dec. 1942
30 Apr. 1943
1 July 1943
1 Oct. 1943
1 Dec. 1943
25 Jan. 1944
5 Apr. 1944
10 June 1944
10 July 1944
28 Aug. 1944
30 Sept 1944
Sp SC #11
Sp SC #20
Sp's SC #31, #41
Sp's SC #50, #59
Sp SC #89
Sp SC #65
Sp SC's #152, #156
Sp SC's #165, #177
Sp SC's #198, #214
Sp SC #221
Sp SC #233
Sp SC #248
 
Tokushima Consolidated Shipbuilidng Co Ltd [Tokushima, Shikoku]? 10 June 1944
28 Aug. 1944
Sp SC #215
Sp SC #234
 
Uraga Dock Co Ltd Uraga Shipyard Yokosuka, Uraga-Machi 20 Aug. 1942
5 Feb. 1943
5 July 1943
31 Aug. 1943
25 Aug. 1944
1 Sept 1944
5 Oct. 1944
Escort Oki
Escort Fukue
Escort Kanju
Escort Kasado
Escort Yaku
Escort Shinnan
Escort Chikubu
 
Yamanishi Shipbuilding and Iron Works Ltd Osaka 25 July 1942
30 Apr. 1943
1 July 1943
25 Aug. 1943
1 Oct. 1943
25 Jan. 1944
5 Apr. 1944
10 June 1944
10 July 1944
28 Aug. 1944
30 Sept 1944
Sp SC's #2, #8
Sp SC's #32, #35
Sp SC #60
Sp SC's #64, #86
Sp SC #92
Sp SC's #151, #155, #163
Sp SC #175
Sp SC's #196, #212
Sp SC #219
Sp SC #231
Sp SC #246

--30--

Escort Craft (Cont'd.)
Yard Location Date of
Announcement
Ship
Yonago Shipyard Co Tottori Ken, Yonago Shi 25 Dec. 1942
1 July 1943
1 Dec. 1943
5 Apr. 1944
10 June 1944
28 Aug. 1944
Sp SC #25
Sp SC #47
Sp SC #85
Sp SC #168
Sp SC #204
Sp SC #238
 
Yokosuka Navy Yard Yokosuka 22 Dec. 1943 Escorts #2, #4, #6, #12, #14, #16
 
Not given   23 June 1944 Escorts #33, #39, #134

--31--

Shipyards Building MTBs

Yard Location Date of
Announcement
Ship
Japan Bridge Co. [Minato-ku, Osaka]? 4 Dec. 1943

25 Jan. 1944

MTB's 301-348, 353, 354,
HAYABUSA Boats 67-73
HAYABUSA Boats 210, 211
 
Kure Navy Yard Kure 4 Dec. 1943

25 Jan. 1944

25 Apr. 1944
20 Oct. 1944

MTB's 349, 350,
HAYABUSA Boats 58-66
MTB's 355-357,
HAYABUSA Boats 74-100, 201-203
HAYABUSA Boats 212, 213
HAYABUSA Boats 226-245
 
Maizuru Navy Yard Maizuru 4 Dec. 1943
25 Jan. 1944
20 Oct. 1944
MTB's 501-516
MTB's 517-528
MTB's 538-553
 
Matsuo Bridge Co [Osaka]? 4 Dec. 1943
25 Jan. 1944
MTB's 349, 350
HAYABUSA Boats 208, 209
 
Mitsubishi Heavy Industries Ltd, Nagasaki Shipyard Nagasaki 4 Dec. 1943
25 Jan. 1944
25 Apr. 1944
20 Oct. 1944
MTB's 451-469
MTB's 484-490
MTB's 801-810, 820-830, MTB's(?) 491, 492
MTB's 871-900, MTB's1101-1108
 
2nd Naval C and R Department Hongkong 15 Apr. 1944 MTB's 151-156
 
102nd Naval C and R Department Soerabaja, Java 25 Oct. 1944 MTB's 157-165
 
Sasebo Navy Yard Sasebo 4 Dec. 1943
23 Jan. 1944
25 Apr. 1944
20 Oct. 1944
MTB's 401-450
MTB's 470-483
MTB's 493-500, MTB's 811-819
MTB's 849-870
HAYABUSA Boats 107-122
 
Tanaka Vehicle Co ? 4 Dec. 1943

25 Jan. 1944

MTB's 351, 352
HAYABUSA Boats 58-66
HAYABUSA Boats 204-207
 
Yokohama Yacht Yard Yokohama 30 June 1941
5 Aug. 1941
5 Mar. 1943
5 July 1943
MTB's 1, 2, 3
MTB's 4, 5, 6
MTB 10
MTB's 11, 12

--32--

MTB (Cont'd.)

Yard Location Date of
Announcement
Ship
Yokohama Yacht Yard Yokohama 4 Dec. 1943
20 Jan. 1944
25 Jan. 1944
30 Mar. 1944
10 July 1944
MTB's 250-262
MTB 13
MTB's 278-286
MTB's 14, 15, 16
MTB's 17, 18
 
Yokosuka Navy Yard Yokosuka 4 Dec. 1943

25 Jan. 1944

25 Apr. 1944
20 Oct. 1944

MTB's 201-249
HAYABUSA Boats 10-16
MTB's 263-277
HAYABUSA Boats 17-26
HAYABUSA Boats 27-32
HAYABUSA Boats 33-46

--33--