Historical Ships of the Japanese Navy (IJN): The Land of the Rising Sun

Introduction

The Imperial Japanese Navy (IJN) was the 3rd largest navy at the outbreak of the Pacific War in December 1941.
Its fleet comprised a dozen different classes of ships built for one task and one task only - winning a decisive battle against The United States of America after a short campaign of attrition.

Edit: Now updated with naval spirits from No Step Back.

Introduction

The Imperial Japanese Navy (IJN) was the 3rd largest navy at the outbreak of the Pacific War in December 1941.
After a short attrition campaign, its fleet comprised a dozen different classes of ships built for one task and one mission only - winning a decisive battle against The United States Navy (USN).

In this guide, I will go through the different ship configurations of ships and which modules they should fit.

NB!

As one of the principal belligerents of the war and supposedly naval superpower, the Japanese already had a considerable fleet at 1.1 1936. However, they lacked the resources/money to build new ships and opted thus for refitting and upgrading most of their existing vessels during the interwar period. Hence this guide is harder to make "clean" than, say, the Kriegsmarine, as the Kriegsmarine needed to start almost from scratch, as they had no ships...
The in-game mechanic for upgrading existing ships is clunky and quickly becomes challenging to navigate the various modifications done... So beware!

Sources: Stille, Mark. The Imperial Japanese Navy in the Pacific War. Osprey Publishing, 2014

Overall Doctrine & Military Spirits

Japanese Doctrine:

The Imperial Japanese Admiralty had, like its adversary the United States Navy (USN), a belief in one significant decisive battle between naval powers. This "Decisive battle" doctrine was the foundation of maritime theory in the pacific.
Therefore, all the Japanese navy ships were seen as support vessels for the battleships. The carriers, which we now know in hindsight was far more potent than any of the naval powers of the time could imagine, was seen as "just another" support vessel.

Naval Doctrine and the United States:

The Japanese admiralty saw it as necessary to declare war on the United States in some form or another due to the Philippines strategic position between the Japanese Main Islands and the Southern Resource Area. They could not predict the American response to an invasion of the Dutch East Indies and British Malay and feared being stabbed in the back while being preoccupied with fighting the Allies in the South-East Pacific.

Japanese original warplan:

The original plan of the Japanese admiralty saw an invasion of the US-controlled Philippines, forcing the Pacific fleet based at Pearl Harbor to respond with force to retake the archipelago.
They imagined the USN would be pressured by public opinion at home to take back the Philippines from the Japanese aggressors, making any move from the Americans predictable. Needing to travel a distance of 4500 nautical miles from Hawaii to the Philippines, the American fleet would be subject to harassment from Japanese submarines and aircraft's, evening out the numerical difference and tiring out the crew as they had done with the Russian Baltic fleet during the Russian-Japanese War. The Japanese could then decide where and when to fight with the initiative in hand for the decisive battle.

As you all know most likely know, Admiral Isoroku Yamamoto scrapped this strategy in favour of his Pearl Harbor Operation. A daring attack from carrier-based aircraft on the US pacific fleet base at Pearl Harbor. However, the plan backfired in the political sphere as it incited public opinion "as a day of infamy" inside the United States.









A wreck of a US battleship after the Pearl Harbor Attack

Naval Spirits

In 1936, Osami Nagoda was Navy Minister in the Japanese cabinet. He would be replaced by Shimada in 1941 before hostilities with the Americans.

Spirit of Academy:

• Integrated Air-Arm is perhaps the most fitting.
  
• Instilled Aggression fits as well.

Spirit of Navy:
A more difficult choice:

• Naval Refit Yard is the most' fitting' due to all the modifications and refits done by the IJN.
  
• Jeune Ecole: The focus on massed torpedos by destroyers makes this fit as well.
  
• Mobile Force: Mobility was imperative for the early success of the Pacific War. The task force attacking Pearl Harbor was named the 1st Mobile Fleet (Dai Icho Kido Kantai).

Spirit of Naval Command:
Again a difficult choice.

• Night Fighting: No other naval force on earth perfected fighting at night as the Japanese military. Only the Allied reliance RADAR (and the Japanese almost total lack thereof) evened the playing field during nighttime.
  
• Close Combat: The emphasis on Jeune Ecole and destroyers fits perfect with practice.
  
• Brave Commanders: The Bushido culture made disengagement seen as cowardly. You attack or die trying.
  
• Suprise Attacks: Pearl Harbor, do I need to say more?

Naval Restriction Treaties

Historical
In the aftermath of the Great War - a battleship arms race was beginning to take shape between the naval powers of Britain, France, Japan, Italy, and the United States. This naval arms race took a heavy toll on the already war-weary economies of the Major Powers. Diplomatic overtures culminated in the Washington Naval Treaty of 1922 ( which capped the tonnage and number of Battleships and carriers) and later the London Naval Treaty of 1930 (that did the same for cruisers). Motivated by its industrial inferiority to the US, Japan joined the subsequent Naval Treaties mentioned. Together with Italy, Japan chose nevertheless to opt-out of the naval treaty system on January 15th 1936 and did not sign the Second London Naval Agreement.
Game mechanics
The Second London Naval conference is in full motion and is due completion after 120 days at the game start. Japan never signed this treaty, but the escalator clause in Italy and Japan left the accord in mars 1937.

The Second London Naval Treaty gives a national spirit that caps the maximum IC a ship can cost to produce.

Heavy ship hulls (BB/BC) is capped at 10,000
Carriers at 9,500
Cruisers at 5,300


The signing of the Washington Naval Treaty of 1920

Fleet Carriers (CV)

Akagi

Had space for 66 planes
Converted Battleship Hull
Hangar (20 planes)
Hangar (20 planes)
Anti-air 2
Heavy Engine 2
Dp

Kaga

Had an hangar capacity of 72 planes:

• 21 Fighters
  
• 27 CAS
  
• 27 Naval plane

Hangar
Hangar
Anti-air 1
Heavy Engine 2
Dp Secondaries 1
M1: Hangar

Soryu/Hiruyu Class

1936 carrier hull
63 aircraft

Deck Space 1	Open Hangar Deck
Deck Space 2	Open Hangar Deck
Anti-Air
Radar
Engine
Secondaries
Armor
Front 1
Mid 1

Shōkaku-class

Hangar space for 72 aircraft: 18F, 27CAS, 27NAV
160,000 shp Kampon boilers
Type 89 12,7 cm DP guns
Type 98 25 cm AA
Type 21 RADAR

Deck Space 1	Open Hangar Deck
Deck Space 2	Open Hangar Deck
Anti-Air
Radar
Engine
Secondaries
Armor
Front 1
Mid 1

Taiho

First Japanese aircraftcarrier with an armoured flight deck!
1940 Carrier Hull
65 aircraft
160,000 shp Kampon Boilers
10cm DP AA guns
Type 96 25cm AA

Deck Space 1	Open Hangar Deck
Deck Space 2	Open Hangar Deck
Anti-Air
Radar
Engine
Secondaries
Armor
Front 1
Mid 1

Unruyu Class

Planned: 16
Completed: 3

Deck Space 1	Open Hangar Deck
Deck Space 2	Open Hangar Deck
Anti-Air
Radar
Engine
Secondaries
Armor
Front 1
Mid 1

An almost exact repeat of the previous Hiruyu class, the Unruyu class had a capacity of 54 aircraft
Type 21 RADAR
104,000 shp Kampon Boilers
12,7cm dual-purpose AA guns
25cm AA

Shinano Class Super-Heavy Carrier

Planned: 1
Completed: 0

Originally laid down as the 3rd "Yamato Class" battleships. It was repurposed during construction. A total capacity of 120 planes.

1944 Carrier Hull
150,000 shp
Type 96 25mm AA
12,7 cm DP guns
Armoured Flight Deck

Light Carriers (CVL)

The IJN had the most aircraft carriers in the world at the outbreak of the war. Most of the "classes" was just a single ship, and are thus marked with not having "class" after its name.

Hosho

It was considered obsolete by the start of the war and with its relative low airgroup of 15 planes (20 in-game) it was a designated support ship.
Converted Cruiser Hull

Deck Space 1	Open Hangar Deck
Deck Space 2
Anti-Air
Radar
Engine	Kampon 65,000hp
Secondaries
Armor

Ryujo

Carried 48 planes.
1936 Carrier Hull

Deck Space 1	Open Hangar Deck
Deck Space 2	Open Hangar Deck
Anti-Air	13mm/76 Type 93
Radar
Engine	Kampon 65,000hp
Secondaries	12cm/45 10th Year Type
Armor
Front 1
Mid 1

Zuiho Class

Constructed: 2
converted cruiser hull

Deck Space 1	Open Hangar Deck
Deck Space 2	Open Hangar Deck
Anti-Air	13mm/76 Type 93
Radar
Engine	Kampon 65,000hp
Secondaries	15cm/50 41s Year Type
Armor

Ryoho

converted cruiser hull
2 x aircraft hangar
Type 96 25mm AA
52,000 shp

Chitose Class

converted cruiser hull
2 x aircraft hangar
Type 96 25mm AA
56,000shp
Type 89 12,7 cm DP guns

Ibuki

Do not build if you are finishing the Ibuki (HC)
Converted cruiser hull
1 aircraft hangar
Aircraft deck armour
RADAR
Dual-purpose secondary armament
Type 96 25mm AA

Hiyu Class

Part of the "Shadow Carrier"-program. Hiyu and her sister ship Junýo was originally built as passenger line ships but was converted to light carriers in 1942.

Converted cruiser hull
Had a capacity for 54 aircraft.
56,000 shp (25knp)
12,7cm dual purpose AA guns
25cm AA

Battleships (BB)

Useage and battleship doctrine:
As stated in the overall doctrine section, the IJN needed a large battlefleet to compete in a gunnery fight with American battleships in one decisive battle for supremacy.
The Battleship and Battlecruisers were almost always held in the reserve as they were too valuable and fuel-hungry to lose. Nevertheless, the Japanese Admiralty never abandoned the idea of the decisive battle, even until its final moments when it was nothing more than a pipedream and self-delusion.

Fusō / Ise Class

Built: 4
Remaining: 4
Trivia: The Ise class was somewhat odd during the war. It was reconstructed as a hybrid carrier-battleship during the war - sadly not possible to replicate in-game.

1922 Heavy Hull

	At game start	Refit
Battery	36cm/45 41st Yr. Type
Anti-Air	13mm/76 Type 93
Fire-Control	Central Rangefinding
Radar/Sonar
Engine	Brown-Curtis 40,000hp	Gihon 80,000hp
Secondaries	15cm/50 41s Year Type
Armor	305mm Belt/76mm Deck
Front 1	36cm/45 41st Yr. Type
Mid 1	12cm/45 10th Year Type
Mid 2	Type 2/No 5 Mod 1 Ct.
Rear 1	36cm/45 41st Yr. Type

Nagato Class

Built: 2

1922 heavy hull

	At game start	Refit
Battery	41 cm/45 3rd Yr. Type naval gun
Anti-Air	13mm/76 Type 93	25mm/60 Type 96
Fire-Control	Central Rangekeeper	Type 92 DCT/Computer
Radar/Sonar
Engine	Gihon 80,000hp
Secondaries	15cm/50 41s Year Type
Armor	305mm Belt/76mm Deck
Front 1
Mid 1	15cm/50 41s Year Type
Mid 2	Type 2/No 5 Mod 1 Ct.
Rear 1	41 cm/45 3rd Yr. Type naval gun

Yamato Class

Planned: 4
Built: 2,5
Super Heavy Hull

Battery	46cm/45 Type 94
Anti-Air	25mm/60 Type 96
Fire-Control	Type 98 DCT/Computer
Radar/Sonar
Engine	Gihon 80,000hp
Secondaries	15,5cm/60 3rd Yr. Type
Armor	410mm Belt/230mm Deck
Front 1	13mm/76 Type 93
Front 2
Mid 1
Mid 2	15,5cm/60 3rd Yr. Type
Mid 3	12,7cm/40 Type 89
Rear 1	46cm/45 Type 94
Rear 2	Type 2/No 1 Mod 10 Catapult

Design A-150 "Super Yamato" Class

Planned: 2
Built: 0
Super Heavy Hull

Battery	46cm/45 Type 94
Anti-Air
Fire-Control	Central Rangekeeper
Radar/Sonar
Engine	Gihon 80,000hp
Secondaries	15,5cm/60 3rd Yr. Type
Armor	410mm Belt/230mm Deck
Front 1
Front 2	12,7cm/40 Type 89
Mid 1
Mid 2	15,5cm/60 3rd Yr. Type
Mid 3
Front 1	46cm/45 Type 94
Front 2	Type 2/No 1 Mod 10 Ct.

Battlecruisers (BC)

Historically the Japanese had a strategy called the "Hachihachi Kantai" - or "8-8 fleet" in English. The strategy was based on the notion that the IJN needed 8 modern battleships and 8 battlecruisers or armoured cruisers to be able to compete with Britain or the US. This has since been abandoned. At the beginning of the game only the Kongo class remain. While historically the Kongo class was refitted to a battleship before the onset of war (Hiei were completed in 1939).

Kongō Class

Completed: 4
Early Heavy Hull

	Original	Service Modification
Battery	36cm/45 41st Yr. Type
Anti-Air	13mm/76 Type 93
Fire-Control	Central Rangefinding
Radar/Sonar
Engine	Gihon 80,000hp
Secondaries	15cm/50 41s Year Type
Armor	203mm Belt/120mm Deck
Front 1	13mm/76 Type 93
Mid 1	15cm/50 41s Year Type
Mid 2	Type 2/No 5 Mod 1 Ct.
Rear 1	36cm/45 41st Yr. Type

Heavy Cruisers (CA)

Preface:
The heavy cruisers were the primary workhorse of the Japanese Navy because of the reluctance to use its battleships and battlecruisers in sorties. The heavy cruiser saw extensive action in support of the invasion of the Dutch East Indies in 1941.
At the outbreak of war, the IJN had 18 Heavy cruisers. Its primary duties were to lead the scouting forces and troop transport escorts. Unfortunately, almost all IJNs heavy cruisers were lost during the war.
Most are already completed, except the Tone class and the never-finished Ibuki class. Therefore, this section will not divide between built and unbuilt.

Furutaka / Aoba Class

Planned: 4
Owned 1.1.1936:4

The Furutaka and Aoba Class Heavy Cruiser were two classes of Japanese heavy cruisers completed before the Washington Naval Treaty, in-game under a common Aoba Class.
Both Furutaka and Aoba were built in pairs - with 2 in both classes.
It was the earliest class of heavy cruisers built for the IJN. It was also the first Japanese ship mounted with an aeroplane catapult.
All ships were modernised in 1936-37. The modernisation included better armour, secondary armament, additional torpedoes, better boilers (engines), improved fire-control systems and AA.
3 of the 4 ships was lost before additional improvements were made.

Myoko Class

Completed: 4
Owned 1.1.1936: 4
The first heavy cruiser was built under the Washington Treaty restrictions.
All ships were modernised before the start of the game (1934-1936). And again between 1938-39.
The second modernisation improved the fire-control system and AA and a better seaplane catapult and torpedo tubes.
The ships were again modernised in 1943 with better main armament and radar, more and better AAs.

Takao Class 4

Completed: 4
Owned 1.1.1936: 4
An improved version of the Myoko Class.
4 were built, and all was completed by 1932.
Takao and Atago were both modernised between 1938-1939:
Improved AA, improved torpedo tubes and better catapults.
It was not until 1942 before the cruisers were fitted with radar.

Mogami Class

Completed: 4
Owned 1.1.1936: 4

Tone Class

Planned: 2
Completed: 2
To IC-heavy at game start to build due to the Treaty limitations. Either cheat on the treaties or abandon it altogether.

Ibuki class

Planned: 2
Completed: 0

1940 Heavy Cruiser Hull
20 cm/50 3rd Year
Type 96 25mm AA
RADAR
Hydrophones
140mm Belt/60mm deck armour
152,000 shp

Light Cruisers (CL) - Part 1: 1910s-1936

The Japanese light cruisers had a different role than their western contemporaries. In the West, the light cruiser often acted as a scout or screener. Meanwhile, in Japan, the CLs was designed and acted as a flagship, command centre and intelligence for destroyer and submarine "Kaiten" (squadrons).
The cruisers were lightly armed, and as most Japanese ships were equipped with torpedo tubes - which also was the LCs main armament as it was intended to take part in the massed torpedo role of the destroyer squadrons. As such the light cruisers were often ill-equipped to duel other light cruisers but had an impressive torpedo armament in comparison.

The Japanese went to war with (only) 17 light cruisers, with another 5 built during the war. As such the light cruiser-arm was maybe the most neglected branch of the Japanese Navy. The light cruiser role as submarine flotilla leader also never had any particular success.

Chikuma Class

Completed: 3

• NB! All ships were scrapped in the interwar period.

Module	Original	Service Modifications
Main Armament	14cm/50 3rd Yr. Type
Anti-Air		25mm/60 Type 96
Fire-Control	Central Rangefinding
RADAR
Engine	Brown-Curtis 51,000hp
Secondaries		12.7mm/40 Type 89 DP
Armor	63mm Belt/45mm Deck
Mid 1
Mid 2
Rear 1

Tenryu Class

Planned: 8
Completed: 2
Early Cruiser Hull

Module	Original	Service Modifications
Main Armament	14cm/50 3rd Yr. Type
Anti-Air		25mm/60 Type 96
Fire-Control	Central Rangefinding
Radar/Sonar
Engine	Brown-Curtis 51,000hp	Mitsubishi 90,000hp
Secondaries
Armor	-	63mm Belt/45mm Deck
Mid 1	Triple 53.3cm TTs
Mid 2
Rear 1	Minelaying Rails

Kuma/Nagara Class

Completed: 11 - 5 + 6
One "Nagara Class" ship was refitted for AA/ASW

Early Cruiser Hull

Module	Original	Service Modifications	Torpedo Cruiser Hull
Main Armament	14cm/50 3rd Yr. Type
Anti-Air		25mm/60 Type 96
Fire-Control	Central Rangefinding
Radar/Sonar
Engine	Mitsubishi 90,000hp
Secondaries		12.7mm/40 Type 89 DP
Armor	63mm Belt/45mm Deck
Mid 1	15cm/50 41s Year Type
Mid 2	Triple 53.3cm TTs
Rear 1	Minelaying Rails

Yubari: 1

Refitted 1944
Main armament "upgraded" to Dual-purpose guns.
1936 Cruiser Huil

Module	Original	Service Modifications
Main Armament	14cm/50 3rd Yr. Type
Anti-Air		25mm/60 Type 96
Fire-Control	Central Rangefinding
Radar/Sonar		Type 22-RADAR
Engine	Mitsubishi 90,000hp
Secondaries
Armor	63mm Belt/45mm Deck
Front 1
Mid 1	Triple 53.3cm TTs
Mid 2
Rear 1	Minelaying Rails	2x Depth-charge(II) throwers

Sendai Class

Planned: 8
Completed: 3
1936 Cruiser Hull

Module	Original	Service Modifications
Main Armament	14cm/50 3rd Yr. Type
Anti-Air	13mm/76 Type 93	25mm/60 Type 96
Fire-Control	Central Rangefinding
Radar/Sonar
Engine	Mitsubishi 90,000hp
Secondaries	15cm/50 41s Year Type	12.7mm/40 Type 89 DP
Armor	63mm Belt/45mm Deck
Front 1
Mid 2	Triple 53.3cm TTs	Type 2/No 5 Mod 1 Ct.
Rear 1	Minelaying Rails

Refittet 1941
improved rangefinding
RADAR
Type 89 DP secondary guns

Light Cruisers (CL) - Part 2 (1937-1945

Katori Class

Planned: 4
Completed: 3
1936 Cruiser Hull

Module	Katori Class	ASW (1944)
Main Armament	14cm/50 3rd Yr. Type	-,,-
AA	13mm/76 Type 93	-,,-
Fire-Control	Central Rangefinding	-,,-
Radar/Sonar	N/A	Type 93 Sonar
Engine	Brown-Curtis 51,000hp	-,,-
Secondaries	15cm/50 41s Year Type	12,7cm/40 Type 89
Armor	N/A	N/A
Front 1	N/A	N/A
Mid 1	Triple 53.3cm TTs	Type 94 DC Thrower
Mid 2	N/A	Depth Charge Rails
Rear 1	Type 2/No 5 Mod 1 Ct.	-,,-

Agano Class

Planned: 4
Completed: 4
1940 Cruiser Hull
15 cm/50 41st Year Type
25mm/60 Type 96
Fire-Control
No. 21 RADAR
60mm Belt/20mm deck armour
100,000shp
2xQuadruple 611mm TT
floatplane
depth-charge throwers
(/Mines)

Ōyodo Class

Planned: 2
Completed: 1
1944 Cruiser Hull
15.5 cm/60 3rd Year Type
Type 96 25 mm AA
Type 94 range-finder
100 mm Type 98 dual-purpose guns as secondary armament
60mm Belt/ 60 mm deck armour
110,000shp
floatplane

Kuchikukan (DD) Part 1: 1917-1936

Comprising the newer and more modern destroyers of the IJN. Was designed as a pure combat vessels similar to the German torpedo boats, rather than the more escort aligned destroyers of the USN and RN.

Kamikaze Class:

Planned:
Completed:
Early Light Hull

Battery	12cm/45 3rd Yr. Type
Anti-Air	13mm/76 Type 93
Fire-Control	Central Rangefinding
Radar/Sonar
Torpedoes	Triple 53.3cm TTs
Engine	Parsons 34,000hp
Mid 1
Rear 1	Depth Charge Rails

Fubuki Class

Planned:
Completed:
1936 Light Hull

Battery	12,7cm/50 Type 3, B mt
Anti-Air
Fire-Control	Central Rangefinding
Radar/Sonar
Torpedoes	Triple 53.3cm TTs
Engine	Kampon 50,000hp
Mid 1	Triple 53.3cm TTs
Rear 1	Depth Charge Rails

Hatsuharu Class

Planned:
Completed:
1936 Light Hull

Battery	12,7cm/50 Type 3, B mt
Anti-Air
Fire-Control	Central Rangefinding
Radar/Sonar
Torpedoes	Triple 53.3cm TTs
Engine	Kampon 50,000hp
Mid 1	Triple 53.3cm TTs
Rear 1	Depth Charge Rails

Kuchikukan (DD) Part 2: 1936-1945

Shiratsuyu Class

Planned:
Completed:
1936 Light Hull

Battery	12,7cm/50 Type 3, B mt
Anti-Air
Fire-Control	Central Rangefinding
Radar/Sonar
Torpedoes	Triple 53.3cm TTs
Engine	Kampon 50,000hp
Mid 1	Triple 53.3cm TTs
Rear 1	Depth Charge Rails

Asashio Class

Planned: 10+18
Completed: 10+19
Built between 1937-1939

1936 light hull

	Original	Service Modifications
Battery	12,7cm/50 3rd Yr. Type C mt.
Anti-Air	25mm/60 Type 96
Fire-Control	Type 92 FC
Radar/Sonar	Type 93 SONAR
Torpedoes	Quadruple 61cm TTs
Engine	Kampon 50,000hp
Locked
Mid 1	Triple 61cm TTs
Rear 1	Depth Charge Rails

Kagero Class

1936 Light Hull

	Original	Service Modifications
Battery	12,7cm/50 3rd Yr. Type, D mt
Anti-Air	25mm/60 Type 96
Fire-Control	Type 92 FC
Radar/Sonar		Type 93 SONAR
Torpedoes	Triple 61cm TTs
Engine	Kampon 50,000hp
Mid 1	Triple 61cm TTs
Rear 1	Depth Charge Rails

Yūgumo Class

Planned: 38
Completed: 19
Built between: 1940-44
1940 light hull

	Original	Service Modifications
Battery	12,7cm/50 3rd Yr. Type, D mt.
Anti-Air	25mm/60 Type 96
Fire-Control	Type 98 FC
Radar/Sonar	Type 93 sonar
Torpedoes	Quadruple 61cm TTs
Engine	Kampon 52,000hp
Locked
Mid 1	Quadruple 61cm TTs
Mid 2
Rear 1	Type 94 DC Thrower

Akizuki Class Anti-Air Escort

Planned: 39
Completed: 12

Battery	10cm/65 Type 98
Anti-Air	25mm/60 Type 96
Fire-Control	Type 98 DCT/Computer
Radar/Sonar	Type 93 Sonar
Torpedoes	Quadruple 61cm TTs
Engine	Kampon 52,000hp
Locked
Mid 1	13mm/76 Type 93
Mid 2	Type 94 DC Thrower
Rear 1	10cm/65 Type 98

Matsu/Tachibana Class:

Planned: 122
Completed: 18 & 14

1944 light hull

Battery	12,7cm/50 Type 1
Anti-Air	25mm/60 Type 96
Fire-Control	Type 98 FC
Radar/Sonar	Type 22 radar
Torpedoes	Quadruple 61cm TTs
Engine	Kampon 52,000hp
Locked
Mid 1	13mm/76 Type 93
Mid 2	Type 94 DC Thrower
Rear 1	10cm/65 Type 98

Kuchikukan: 2nd Class Fleet Destroyers

The destroyers were the second most successful ship type of the Imperial Japanese Navy.

The Destroyers were designed with the role of harassing the enemy battle line with a massive torpedo barrage during the decisive battle and the subsequent mop-up operation. With the thought of the destroyer as a surface-combat ship, the design never emphasised Anti-Submarine Warfare (ASW) - although they had a limited capability. As a result of the lack of ASW, many war-, and merchant's vessels were sunk by Allied submarines.
The destroyer classes were divided into 1st and 2nd class destroyers. The second class destroyers had the role of escort and support ships during amphibious operations.

Already constructed or under construction 1.1 1936:

Nitto Kuchikukan Class

Built: 28
Remaining in service 1936: 21+6 (Wakatake Class)
The in-game Momi class also comprises the Watakake experimental destroyer class. Where 6 of the original 8 remain.

Early Destroyer Hull

	Original	Escort Modifications
Battery	12cm/45 3rd Yr. Type
Anti-Air		25mm/60 Type 96
Fire-Control	FTC 0
Radar/Sonar
Torpedoes	Triple 53.3cm TTs	REMOVED
Engine	Parsons 34,000hp
Mid 1		AA II
Rear 1	Minesweeping Eqp.	DC II

Minekaze Class:

Completed: 41

• NB! Combination of: Minekaze, Kamikaze, and Mutsuki class destroyers

• Shimakaze and Nadakaze were refitted as destroyer transports. The rest of the remaining 12 ships were refitted as convoy escorts in 1941; one of the main battery was removed, a large increase in AA armament, and the minelaying/sweeping capabilities were also removed in favour of depth-charges (ASW).
  
  

  	Original	Service Modifications
  Battery	12cm/45 3rd Yr. Type
  Anti-Air
  Fire-Control	Central Rangefinding
  Radar/Sonar
  Torpedoes	Triple 61cm TTs
  Engine
  Mid 1	Triple 61cm TTs
  Rear 1	Type 94 DC Thrower

Kaibokan - Destroyer Escorts

Build as cheaply as possible
Convoy escort was something the Japanese Admiralty neglected until 1942 when it became clear that the war would be drawn out one and that they (the IJN) did not have a vessel really built for the purpose of escort duty. The Kaibokan was one of the few Japanese vessels of war not built with torpedo tubes.

Shimusu Class: 4

1936 destroyer hull
12cm/45 11th Yr. Type
25mm/96 AA
Type 22 RADAR (1943)
Depth charge mortar (III)

Etorfu Class: 14

1936 destroyer hull
12cm/45 11th Yr. Type
25mm/96 AA
Type 93 SONAR
Depth charge mortar (III)

Mikura Class: 8

1936 destroyer hull
12cm/45 11th Yr. Type
25mm/96 AA
Type 93 SONAR
Depth charge mortar (III)

• I have also opted to decrease the Destroyer hull level in later designs to reflect how Japan needed to conserve as many resources as possible as the fortunes of war shifted and resources got scarcer. If your war dear reader fares better, use the most modern hulls available.

Ukuru Class: 20

1922 destroyer hull
12cm/45 11th Yr. Type
25mm/96 AA
Type 93 SONAR
Minesweeping gear
Depth charge mortar (III)

C-Class: 56/300

1922 destroyer hull
12cm/45 11th Yr. Type
25mm/96 AA
Type 93 SONAR
Improved rangefinder
Minesweeping gear
Depth charge mortar (III)

D-Class:67/203

1922 destroyer hull
12cm/45 11th Yr. Type
25mm/96 AA
Type 93 SONAR
Type 22 RADAR
Minesweeping gear
Depth charge mortar (III)

Submarines

The IJN's concept of submarine warfare was using long-range submarines in squadrons (sentai) to attack enemy combat vessels at extended ranges. These submarines would be coordinated by a cruiser, which would use reconnaissance aircraft to provide targeting information. Little emphasis was placed on commerce raiding.

Another thing to note is the confusing way Japan named their submarines. All submarines were renamed in 1942 with an additional "1" before its numbers; thus, (s) multiple I-53 subs, for example.

Kaichun IV Class

Completed:
At game start: 26
Most of the RO-26 Class would end up being decommissioned beginning in 1932.
The RO series of submarines was smaller than their oceangoing KD and A relatives. They was designed to operate in coastal waters. Many of the starting submarines would be decommissioned between 1936 and 1940, with only 12 of the original 22 remaining.
Early Submarine Hull

Modules
Torpedo Tubes	4 x 53,3cm Type 15 TTs
Engines	Sulzer 2,600hp
Rear 1

Kaidai III Class:

1936 Submarine Hull

Modules
Torpedo Tubes	4 x 53,3cm Type 15 TTs
Engines	Sulzer 2,600hp
Rear 1	4 x 53,3cm Type 15 TTs

Subclass	Number built
KD3A/B	9
KD4	3
KD5	3
KD6A/B	8
KD7	10
Total	33

C1/C2 Class

Completed: 5 + 3
Just a continuum of the existing KD class with an
improved machinery.

Kiraisen Class

Completed: 4
Japanese submarine based on the German Type II submarine. Was equipped with minelaying capabilities.
1936 Submarine Hull

Modules
Torpedo Tubes	4 x 53,3cm Type 15 TTs
Engines	Sulzer 2,600hp
Rear 1	Mine Laying Tubes

C4 Types

Planned: 15
Completed: 3
1940 submarine hull
8 TTs
Engine II

Sen-Taka Class

3
1944 submarine hull
4 x 53,3 cm TT

A1/A2 Class

Completed: 4 +2AM Class submarines impossible to implement in-game
Cruiser class submarine hull

Modules
Torpedo Tubes	4 x 53,3cm Type 15 TTs
Engines	Sulzer 2,600hp
Front 1	Type 2/No 5 Mod 1 Ct.
Mid 1
Rear 1

6 x 53,3 cm TT
Sulzer 6800 shp machinery
Floatplane I
Fuel tank

B Type Submarine

20
Just a repeat of the A1/A2 class...
with improved floatplane
Cruiser Submarine Hull

Modules	B1	B3/B4
Torpedo Tubes	4 x 53,3cm Type 15 TTs
Engines	Sulzer 2,600hp
Front 1	Type 2/No 1 Mod 10 Ct.
Mid 1		Type 23 Radar
Rear 1

Merchant Navy

The Japanese navy was seriously short on merchant ships. As such, they had a problem of keeping the occupied areas supplied. US submarines and air-power did not, however, lighten the burden on the already stretched shipping-lanes from the Japanese Home Islands.

Minelayers

The minelayer had a little part in the overall IJN strategy. The Minelayers here are ordered after the naming list in chronological order.

Okinoshima Minelaying-Cruiser: 1

1922 cruiser hull

• 14 cm/50 3rd Year Type
  
• Type 93 13mm AA
  
• 500 naval mines
  
• depth charges
  
• seaplane

Hatsutaka destroyer-minelayer Class: 3

1936 destroyer hull

• 12cm/45 11th Yr. Type
  
• Type 93 Hydrophone
  
• Type 93 SONAR
  
• 1 Minelaying rails
  
• Depth charge throwers (II)
  
• [Anti-mine]

Tsugaru minelaying-cruiser: 1

1936 cruiser hull

• 12,7cm / 3rd yr.
  
• Type 93 13mm AA
  
• Motor I
  
• Depth charge throwers (II)
  
• Minelaying rails
  
• Seaplane
  

Eijo minelaying-cruiser Class: 2

Early cruiser hull (1922)

• 12cm /45 11th Yr. Type
  
• 25mm AA
  
• Minelaying rails
  
• Depth charge rails

Other Guides

Naval Guides

The Allies:

• The Royal Navy: A historical guide to naval construction 1936-1945
  
• Marine Nationale: French Naval building 1936-1945
  
• US Navy: A Two Ocean Navy

Axis:

• Die Kriegsmarine & Der Z-Plan: A guide to historical naval construction 1936-1945
  
• The Regina Marina: A guide to historical naval construction 1936-1945
  
• The Imperial Japanese Navy: A guide to historical naval construction 1936-1945

Comintern:
Stalin´s Oceangoing Navy

Tank Guides:

The Allies:

• United Kingdom Historical Tank Guide
  
• United States Historical Tank Guide

The Axis

• German Historical Tank Guide
  
• Italian guide to historical tanks

The Cominterns

• Soviet Historical Tank Guide

Module names

The names of the modules as they appear in-game is used throughout this guide. Check this for reference.

Armament	Level I	Level II	Level III	Level IV	Level V / Special
Light Battery	10.5cm/55 SK C/28	12.7cm/45 SK C/34	15cm/48 Tbts KC/36	12.7cm/45 SK C/41
Dual-Purpose Main Armamente	10.5cm/55 SK C/28	12.7cm/45 SK C/41 DP	12.7cm/45 SK C/41 DP	12.7cm/45 SK C/41
Medium Battery	15cm/45 SK L/45	15cm/60 SK C/25	15cm/55 C/28	15cm/55 SK C/28 Auto-Loading	15cm/48 Tbts KC/36T DP
Heavy Cruiser Battery	21cm/45 SK L/45	20.3cm/60 SK C/34	20.3cm/60 w/RPC	20.3cm/60 Selbstllader
Heavy Battery	28cm/40 SK L/40	28cm/54.5 SK C/34	38cm/52 SK C/34	40.6cm/52 SK C/34	46 cm Cannon (Super Heavy Battery)
Torpedoes	4 x 533mm Torp. Tubes	6 x 533mm Torp. Tubes	6 x 533mm w/L. Pistons	6 x 533mm w/P.Loading

Miscellaneous	Level I	Level II	Level III	Level IV	Special
Fire Control System	Cental Rangefinding	Type 1935 (C. 35)	Mechanical Rangekeeper	Ballistic Computer
RADAR	FuMO 22 Radar	FuMO 26 Radar	FuMO 27 Radar	FuMO 34 Radar
Sonar	Atlas-Werke GHG	S-Gerät
Secondary Battery	15cm/45 SK L/45	15cm/55 Drh L. C/34
Dual-Purpose Secondary Battery	8.8cm/45 Flak L/45	10.5cm/65 SK C/33	12.7cm/61 KM 40	12.7cm/45 SK C/41 DP
Anti-Air	2cm/65 C/30	2cm/65 C/38 Flak 35	3.7cm/57 Flak M43	40mm Quad AA
Torpedo Tubes	3 x 500mm TTs	4 x 533mm TTs	4 x 533mm w/Comp. Air	5 x 533mm w/Comp. Air
Anti-Submarine Warfare	Depth Charge Rails	Rheimmetall DC Thrower	Anti-Submarine Mortar	Advanced Anti-Submarine Mortar
Aircraft Facilities	Floatplane Catapult	Improved Floatplane Catapult
Mine Warfare					Minelaying Rails Minesweeping Gear Minelaying Tubes

[Magni]

I think you forgot the Akizuki class among the fleet destroyers?

[IgnacioLuchaLibreNacho]

Instilled Aggression does not fit too well with the Japanese, they were more pragmatic than being overly aggressive. With a smaller fleet, risking their own ships would not be worthwhile in some cases. Such as Admiral Mikawa after the Battle of Savo Island, he could have destroyed the vulnerable supply fleet off Guadalcanal (most likely making the Battle of Henderson field in favor of Japan), but turned back before daybreak for fear of unknown American fleets. Admiral Tanaka, on a supply mission to Guadalcanal, did not continue with the supply mission after exchanging fire with American cruisers because as far as he knew, there was more out there. Night Fighting or Close Combat are more realistic choices.

[Kirito031]

and light carriers are CVL

[Kirito031]

you put CA twice fleet carriers are CV. Just pointing that out, also good guide

[Kåra]

@Camo. Thank you for spotting my mistake! Kaga is indeed not a light carrier.
The mistake has been corrected.

[Camo]

I don't recall the Kaga being a light/escort carrier of any sort honestly. As for a few other carriers such as Akagi they were originally Battleship or Cruiser halls but were converted into aircraft carriers like the Kaga. Most of the IJN is confusing and takes a lot of hard copy in depth reading to fully understand which is notable to see but, overall this looks cool.

[Ahlesdurr]

Any tips for these guides' fleet configurations. Like, damn, I get confused when trying to make 1st, 2nd, 3rd, 4th, and 5th Fleets. Not to mention the 1st Air Fleet

[SaltySeeds06]

Sorry I don't speak Anime

[stingray20]

When will it be finished?

[Will2brown]

Wow. Lots of detail