Imperial Japanese Navy
World War II
Production Programs

References:
Japanese Cruisers of the Pacific War by Eric Lacroix and Linton Wells
Kaigun: Strategy, Tactics, and Technology in the Imperial Japanese Navy, 1887-1941 by David Evans
The Imperial Japanese Navy by A.J. Watts and B.G. Gordon
Google Translate Page
Kanji Converter Page

NOTE: Numbers given for smaller combatants may not be exact, due to the difficulty in counting numbers etc.

Pre-War Programs

第一次海軍軍備補充計画 (Dai-Ichi-Ji Kaigun Gunbi Hojū Keikaku) or First Naval Armaments Supplement Program
マル①計画 (Maru 1 Keikaku) or Circle One Program
28 March 1931

Cost: ¥247,080,000 for new ship construction
4 x Mogami Light Cruisers
12 x
Hatsuharu Destroyers
4 x
Chidori Torpedo Boats
1 x
I-6 Cruiser Submarine
6 x
I-68 Large Submarines
2 x
Ro-33 Large Submarines
1 x
Okinoshima Minelayers
3 x
Natsushima Minelayers
6 x
No.13 Minesweepers
Circle One Supplement (1932)
1 x Taigei Submarine Tender
2 x
No.1 Subchasers

第二次海軍軍備補充計画 (Dai-Ni-Ji Kaigun Gunbi Hojū Keikaku) or Second Naval Armaments Supplement Program
マル②計画 (Maru 2 Keikaku) or Circle Two Program
1934

Cost: ¥431,688,000 for new ship construction
2 x Tone (C-38) Medium / Heavy Cruisers (were rebuilt to use 8” guns during construction) (No.5 and No.6)
2 x
Soryu CVs (one was later built as the Hiryu)
4 x
Shiratsuyu DD
10 x
Asashio DD
16 x
Otori Torpedo Boats
2 x
Junsen III Cruiser Submarines
2 x
Kadai VI Large Submarines
2 x
Chitose Seaplane Tenders, Type A (10,000 ton)
1 x
Mizuho Seaplane Tender, Type B (9,000 ton)
1 x
PC-3 Subchaser
2 x
No.251 Subchasers (Diesel Powered)
1 x
No.251 Subchaser (Turbine Powered)
2 x
Tsurugizaki Fleet Oilers
1 x
Akashi Repair Ship
Summary:
2 x Cruisers
2 x Carriers
14 x Destroyers
16 x Torpedo Boats
4 x Submarines
3 x Seaplane Tenders
4 x Subchasers
2 x Fleet Oilers
1 x Repair Ship

第三次海軍軍備補充計画 (Dai-San-Ji Kaigun Gunbi Hojū Keikaku) or Third Naval Armaments Supplement Program
マル③計画 (Maru 3 Keikaku) or Circle Three Program
1937

Cost: ¥806,549,000 for new ship construction
2 x Yamato Battleships (No. 1 Yamato and No. 2 Musashi)
2 x Shokaku Aircraft Carriers (No. 3 Shokaku and No. 4)
18 x Kagero Destroyers (Type A) (No. 17 to 34)
4 x Shimushu Escort Ships (Type A) (No. 9 to 12)
9 x No.4 Subchasers (Ships No 62 to 70)
2 x Hashidate Gunboats (Type A) (No. 13 and 14)
2 x Fushimi Gunboats (Type B) (No. 15 and 16)
2 x I-9 Cruiser Submarines (Type A) (No. 35 and 36)
7 x I-15 Cruiser Submarines (Type B)
5 x I-16 Cruiser Submarines (Type C) (No. 44 to 48)
1 x No.71 Experimental Submarine
5 x Sokuten Minelayers (No. 57 to 61)
1 x Nissin Minelayer (No. 5)
1 x Tsugaru Minelayer (No. 6)
2 x Hatsutaka Minelayers (No 7 and 8)
6 x No.7 Minesweepers (No. 49 to 54)
1 x Kashino Munitions Transport (No. 55)
1 x Tsukushi Survey Ship (No. 56)

1938 Supplementary Program

2 x Katori Training Cruisers (No. 72 and No. 73)
1 x Irako Food Supply Ship (No. 74)

第四次海軍軍備補充計画 (Dai-Ni-Ji Kaigun Gunbi Hojū Keikaku) or Fourth Naval Armaments Supplement Program
マル④計画 (Maru 4 Keikaku) or Circle Four Program
1939

Cost: ¥205,780,000 for new ship construction
2 x Yamato Battleships (No. 110 Shinano and No. 111)
1 x
Taiho Aircraft Carrier (No. 130)
4 x
Agano (C-41) Light Cruisers (Type B) (No. 132 to 135)
2 x
Oyodo (C-42) Light Cruisers (Type C) (No. 136 and No. 137)
1 x
Katori Training Cruiser (No. 101)
15 x
Yugumo Destroyers (Type A)
3 x
Kagero Destroyers (Type A) (No. 112 to 114)
6 x
Akizuki Destroyers (Type B)
1 x
Shimakaze Destroyer (Type C) (No. 125)
4 x
No.13 Subchasers (No. 180 to 183)
1 x
I-9 Cruiser Submarine (Type A)
15 x
I-15 Cruiser Submarines (Type B)
10 x
I-176 Large Submarines
6 x MSC-19 Minesweepers (No. 164 to 169)
10 x
Sokuten Minelayers
1 x
Hatsutaka Minelayer
1 x
Akitsushima Seaplane Tender (No. 131)
1 x
Sunosaki Combat Support Ship (No. 103)
4 x
Hashima Cable Layers
1 x
Nankai Food Supply Ship
1 x
Nanshin Food Supply Ship
1 x
Wakataka Netlayer (No. 102)
6 x
Akizuki Destroyers (No. 104 to 109)
12 x
Yugumo Destroyers (No. 115 to 124, No. 126 and No. 127)
2 x
Yugumo Destroyers (No. 128 and No. 129 – actually were dummy ships to mask the costs of the Yamato program)
1 x I-11 Submarine (No.138)
14 x I-26 Submarines (No. 139 to 152)
1 x Unknown Ship (No. 153)
10 x I-76 Submarines (No. 154 to 163)
10 x
Hirashima Minelayers (No. 170 to 179)

Temporal Naval Armaments Supplement Program
マル凛計画 (Maru Rin Keikaku)
October 1940

11 x No.13 Subchasers (No. 184 to 194)
9 x
Ro-35 Medium Submarines (No. 201 to 209)
9 x
Ro-100 Medium Submarines (No. 210 to 218)
2 x
Ashizuri Combat Support Ships (No. 219 and No. 220)
4 x
Sunosaki Combat Support Ships (No. 233 to 236)
1 x
Katori Training Cruiser (No. 237)
6 x
AMS-1 Auxiliary Minesweepers (No. 251 to 256)
4 x
AMC-1 Auxiliary Minelayers (No. 257 to 260)
3 x
Kinesaki Food Ships (No. 261 to 263)

第五次海軍軍備補充計画 (Dai-Go-Ji Kaigun Gunbi Hojū Keikaku) or Fifth Naval Armaments Supplement Program
マル⑤計画 (Maru 5 Keikaku) or Circle Five Program
May 1941

The Navy Ministry expected that it couldn't be started until 1942, and that it would take nine years (until 1950) to finish all 159 units in the plan.
1 x Yamato Battleship (No. 797)
2 x
A-150 “Super Yamato” Battleships (No 798 and No. 799)
2 x Type A Battlecruisers (
Nos 795 to 796)
1 x
Unryu Aircraft Carrier (No. 800)
2 x
Kai-Taiho (G-14) Aircraft Carriers (No 801 and No 802)
1 x 11,000 ton Seaplane Tender (No. 809)
1 x
Kai-Wakataka Netlayer (No. 819)
1 x
Irako Supply Tanker (No. 845)
5 x
Kai-Agano (C-44) Type B Cruisers (Nos 810 to 814)
1 x 6,800 ton Icebreaker (
No. 846)
1 x
Tsukushi Survey Ship (No. 847)
1 x
Hashidate Gunboat (No. 867)
1 x I-400 Class Submarine (No. 714)
2 x
I-9 Cruiser Submarines (Type A) (No. 700 and No. 701)
8 x
I-15 Cruiser Submarines (Type B) (Nos. 702 to 709)
4 x
I-46 Submarines (Nos. 710 to 713)
3 x
I-351 Submarines (Nos. 730 to 732)
9 x
RO-35 Submarines (Nos. 715 to 723)
10 x
I-176 Submarines (Unknown Numbers)
9 x
RO-100 Submarines (Unknown Numbers)
16 x
Kai-Shimakaze Destroyers (No. 733 to 748)
16 x
Kai-Akitsuki Destroyers (No. 770 to 785)
4 x
Shumushu Escorts (Type A) (No. 790 to 793)
6 x 3,300 ton Seaplane Tenders (No. 803 to 808)
4 x
Shokatu Escort Cruisers (No 815 to 818)
10 x
No.19 Minesweepers (No. 820 to 829)
2 x
Akashi Repair Ships (No. 840 and No. 841)
3 x Improved Kazahaya Supply Tankers (No. 842 to 844)
8 x
Ajiro Minelayers (No. 850 to 857)
2 x Modified
Nisshin Seaplane Carrier (No. 863 and No. 864)
2 x Modified
Tsurugizaki Submarine Depot Ships (No. 865 and No. 866)
2 x
Sumida Gunboats (No. 868 and No. 869)
9 x
No.13 (CH-13) Subchasers (No. 870 to 878)
9 x 700 ton CH-60 Subchasers (No. 879 to 887)
2 x
Tsugaru Minelayers

第六次海軍軍備補充計画 (Dai-Roku-Ji Kaigun Gunbi Hojū Keikaku) or Sixth Naval Armaments Supplement Program
マル⑥計画 (Maru 6 Keikaku) or Circle Six Program

Not much is known about this plan. It was abandoned at a very early stage in planning. The January 1941 Proposal had the following:
4 x Super Type A Cruisers
8 x Type A Cruisers (CAs)
1 x Type B Cruiser (CL)
1 x Type C Cruiser

Wartime Programs

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

1941 Wartime Construction Program

Construction Priority List (in order of priority)

1. ) Aircraft
2. ) Submarines
3. ) Aircraft Carriers/Escort Vessels
4. ) Destroyers
5. ) Transports
6. ) Cruisers
7. ) Battleships
8. ) Battlecruisers

Standardization:

Existing designs were to be standardized for mass production, with slight detail improvements.

Cruisers: Suzuya (Modified Mogami class)

The 1941 Wartime Construction Program consisted of the following two programs:

Wartime Urgent Warship-Construction Program
マル級計画 (Maru Kyū Keikaku) or Circle Urgent Program
21 September 1941

Note: Decided upon by the Naval General Staff on 28 July 1941, but not activated until 21 September 1941.
1 x Unryu Aircraft Carrier (No. 302)
2 x
Ibuki Heavy Cruisers (No. 300 (Ibuki) and No. 301)
30 x
Etorofu Escort Ships (Type Mod-A) (No. 310 to 339) (many were later reordered/converted to Mikura/Hiburi/Ukuru Type B Escort Ships)
16 x
Yugumo Destroyers (Type A) (No. 340 to 355)
10 x
Akizuki Destroyers (Type B) (No. 360 to 369)
6 x
I-40 Cruiser Submarines (Type B) (No. 370 to 375)
3 x
I-16 Cruiser Submarines (Type C) (No. 376 to 378)
3 x
S49B Cruiser Submarine (Type C) (No. 379 to 381) (All Cancelled)
12 x
Ro-35 Medium Submarines (No. 385 to 396)
9 x
Ro-100 Medium Submarines (No. 400 to 408)
28 x
MSC-19 Minesweepers (No. 410 to 437)
20 x
No.13 Subchasers (No. 440 to 459)
14 x
Ajiro Minelayers (No. 460 to 473)
16 x
AMS-1 Auxiliary Minesweepers (No. 480 to 495)
100 x
APC-1 (CHa-1) Auxiliary Subchasers (No. 500 to 599)
1 x
PT-10 Torpedo Boat (No. 600)
17 x
PT-11 Torpedo Boats (No. 601 to 617)

Additional Naval Armaments Supplement Program
マル追計画 (Maru Tsui Keikaku) or Circle Additional Program
November 1941

1 x I-12 Cruiser Submarine (Type A) (No. 620)
1 x
I-13 Cruiser Submarine (Type A) (No. 621)
7 x
I-54 Cruiser Submarines (Type B) (No. 627, No. 629, No 631, No 633, No 634, No 635, and No 636)
5 x
I-52 Cruiser Submarines (Type C) (No. 625, No. 626, No. 628, No. 630, and No. 632)
15 x
Ro-35 Medium Submarines (No. 640 to 654)
3 x
I-351 Cargo/Tanker Submarines (No. 655 to 657)
1 x
Hakachi Target Ship (No. 660)

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

1942 Warship Construction Replenishment Program (21 September 1941)

Notes: Combined the earlier Fifth and Sixth Replenishment Programs (Circle Five and Six) into a single program, consisting of two parts:
Part One (Mainly the original Circle Five program). Construction to be started in 1942 and finished before 1 April 1948 (the end of Japanese Fiscal Year 1947).
Part Two (Mainly the original Circle Six Program). No decision was made on this program.

Wartime Warship Construction Replenishment Program
改マル⑤計画 (Kai-Maru 5 Keikaku) or Modified Circle Five Program
21 September 1942

Notes: Replaced the earlier Circle Five program, which was canceled.
15 x Unryu Aircraft Carriers (Nos 5001 to 5015)
5 x Kai-Taiho (G-15) Aircraft Carriers (Nos 5021 to 5025)
2 x Kai-Agano (C-44) Type B Cruisers (No. 5037 and No. 5038)
23 x Yamatsuki Destroyers (No. 5061 to 5083)
8 x
Yasmasame Destroyers (No. 5041 to 5048)
42 x Matsu Destroyers (Type D) (No. 5481 to 5522)
34 x Yaku Escorts (No. 5251 to 5284)
30 x No.60 Subchasers (No. 5341 to 5370)
18 x
No.28 MTBs (No. 5441 to 5458)
14 x I-54 Submarines (No. 5101 to 5114)
18 x Improved I-54 Submarines (No. 5115 to 5155)
15 x I-52 Submarines (No. 5141 to 5155)
18 x I-400 Submarines (No. 5231 to 5248)
6 x
I-14 Submarines (No. 5091 to 5096)
25 x
Improved I-52 Submarines (No. 5156 to 5180)
42 x
RO-35 Submarines (No. 5181 to 5223)
11 x
I-361 Submarines (Type D) (No. 5461 to 5471)
3 x
Shilo Submarine Depot Ships (No. 5034 to 5036)
3 x
Akitsushima Seaplane Tenders (No. 5031 to 5033)
5 x
Ohama Target Ships (No. 5411 to 5415)
1 x
Asadori Netlayer (No. 5039)
12 x Arashima Minelayers (No. 5421 to 5432)
36 x No.53 Minesweepers (No. 5301 to 5336)
7 x Kiyozaki Refrigerated Ships (No. 5401 to 5407)
1 x Kusunii Supply Ship (No. 5408)
1 x Miho Survey Ship (No. 5418)
1 x Esau Icebreaker (No. 5419)
2 x Mikara Repair Ships (No. 5416 and No. 5417)
7 x Hayasui Supply Tankers (No. 5381 to 5387)
8 x Takano Supply Tankers (No. 5388 to 5395)
2 x Hario Supply Ships (No. 5409 and No. 5410)

Wartime Naval Armaments Supplement Program
マル戦計画 (Maru Sen Keikaku) or Circle War Program
1943-44 Program

100 x No.151 Auxiliary Subchaser (No. 2001 to 2100)
280 x Type B-1 Patrol Boats (No. 2121 to 2400)
132 x No.1 Escort (No.2401 to 2532)
143 x No.2 Escort (No. 2701 to 2843)
46 x No.1 Transports (No. 2901 to 2946)
1 x I-372 Submarine (No. 2961)
6 x I-373 Submarines (No. 2962 to 2967)
73 x No.101 LSTs (No. 1501 to 1603)
60 x No.101 Auxiliary Patrol Boat (No. 1701 to 1760)
9 x Kamishima Minelayers (No. 1801 to 1809)
2 x
Minoo Minelayers (No. 1821 and No. 1822)
20 x
No.1 Auxiliary Patrol Boats (No. 1851 to 1870)
23 x I-201 Submarines (No. 4501 to 4532)
12 x HA-101 Submarines (No. 4601 to 4612)
21 x
Inagi Escorts (No. 4701 to 4721)
20 x Modified
Matsu Destroyers (No. 4801 to 4820)
2 x
Hario Supply Tankers (No. 4901 and No. 4902)
2 x
Inatori Supply Tankers (No. 4903 and No. 4904)
79 x HA-201 Submarines (No. 4911 to 4989)

1944-45 War Program

Notes: Projected, but none were ever ordered, and thus not assigned numbers.
79 x Type B Escorts
60 x Type D Escorts
10 x HA-201 Submarines
20 x No.151 Subchasers
4 x No.1 Transports
92 x I-361 Submarines
11 x Kamishima Minelayers
13 x Cargo Submarines
168 x
No.1 Escorts
60 x
No.2 Escorts
88 x
HA-101 Submarines
140 x
I-373 Submarines
76 x
I-201 Submarines
40 x
No.101 Auxiliary Patrol Boats
Summary:
367 x Escorts
20 x Subchasers
40 x Auxiliary Patrol Boats
419 x Submarines
11 x Minelayers
4 x Transports

Miscellaneous Notes:

The Taiho Class Aircraft Carriers were originally planned to have the following air group as completed:

24 x A7M Reppui (Sam)
25 x B7A2 Ryusei (Grace)
4 x C6N1 Saiun (Myrt)