Japanese Naval Shipbuilding

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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.

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 modem battleships, and her light screening forces have become fewer and fewer.

Shipbuilding Centers

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

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)

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

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)

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

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)

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

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)

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.

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)

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.

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

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

Destroyers (Cont'd.)

Yard	Location	Date of Announcement	Ship
Uraga Doc 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 Tachiibana Tsuta

 

 

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

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

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

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 incompleted captured 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

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

Auxiliaries (Cont'd.)

Yard	Location	Date of Announcement	Ship
Mitsubishi Heavy Industries Ltd, Nagasaki Shipyard	Nagasaki	1 Mar 1942   25 Dec 1942	Auxiliary Ashizuri Auxilialry Shioya
Osaka Iro 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

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's SC #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. Mururan 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

Escort Craft (Cont'd.)

Yard	Location	Date of Announcement	Ship
Harima Shipbuilding Co Ltd.	Hyogo Ken, O Shi	23 June 1944   25 Aug 1944   12 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	Escorts Hirato, SC #46 Escort Amakusa Escort Awaji Escort Nomi Escorts Yashior and Hiburi Escot 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 #33 Sp SC's #34, #45 Sp SC #55 Sp SC #69 Sp SC #79, #96 Sp SC's #164, #176 Sp SC's #197, #213 Sp SC #220 Sp SC #232 Sp SC #247

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 Escort #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 Ammami, 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

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

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 Septy 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

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 incomplete 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 Iro 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

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

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

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 Decc. 1943   25 Jan 1944	MTB's 34, 350, HAYABUSA Boats 58-66 MTB's 355-357, HAYABUSA Boats 74-100, 201-203
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 34, 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 1101-1108
2nd Naval C and R Department	Hongkong	15 Apr 1944	MTB's 151-156
1020nd 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, 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

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