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HoI4 Dev Diary - The Imperial Japanese Navy (AAR)

Hello, and welcome back to another Dev Diary from the frozen wasteland that is Sweden in January. Today, we will have another short AAR of a naval warfare scenario, similar to the one we did earlier about raiding and submarine warfare.


This was played as an MP game between me and Niall (@Ceebie), with me defending the Empire of Japan’s honor against Niall’s filthy American imperialists.


Starting as Japan, I immediately face a number of issues that should sound very familiar: I have very limited resources, particularly in terms of oil. This is now a much bigger issue as I can still happily build ships and airplanes and tanks, but I won’t be able to run them for free. However, if I want to upgrade my ships (and knowing Niall, I absolutely do), I will need naval experience, and China is unlikely to provide me with a lot of it. So I need to run training missions for my fleet, which gobbles up fuel at a rapid pace (I could only take out my main fleet units for a few brief weeks before the fuel situation became critical).


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At the same time, while I could trade for more oil, it will cost civilian factories which I desperately need to build up my own industry or to trade for steel to continue my military buildup. I decided to keep the trading for oil to a minimum in order to more quickly build up my industry and increase the size of my fleet.


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My first target is, of course, China, and we start the war with them in the middle of 1937. It quickly becomes apparent that I underestimate the Chinese. Fighting rages hard along the border for several weeks, and a number of naval landings that attempt to force the AI to draw troops away from the main front are quickly contained by local garrisons, but at least not pushed back into the sea. Part of the problem is that the fleets tasked with invasion support contain some of my battleships, which eat up absurd amounts of fuel, and my attempts to turn the tide through prolific use of air support eat into my fuel supplies even more.


By early 1938, we are slowly grinding forward and have managed to inflict serious casualties on the Chinese, but my fuel stockpile has shrunken to just 30 days of current use. I curtail air support to only support my main thrust and send the naval forces providing shore bombardment back to port. Progress slows, but eventually we link up with the landing forces, at least saving me from an embarrassing early defeat. The massive amounts of Land XP also allow me to run through the doctrine tree quite a bit faster than Niall could ever hope to. Sadly the war in the Pacific will not be fought on land.


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It would take until early 1941 for the Chinese to fall, even though the writing is on the wall by the middle of 1940. I blame the poor infrastructure and awful terrain in China - my leadership is, after all, beyond any reasonable doubt.


In the meantime, Niall has been quietly modernizing his fleet and has started his rearmament. While a good amount of his effort is spent on helping out the British in Europe, I have no doubt that he has something in store for me. While I was deeply engaged in managing the war in China, I received some out-of-game intelligence (Niall bragging in the kitchen that his destroyer swarms would annihilate me) that makes me realize that my fleet lacks some key capabilities. The starting Japanese light cruisers are fairly mediocre, most have been built during the 20ies and are not up to the task of winning a firefight against the likes of a Brooklyn Class cruiser with no less than 3 light cruiser battery modules. What I do have is a lot of torpedoes, and I invest a little into researching upgraded torpedoes and better launchers. The Japanese Long Lance national spirit gives me another perk, as it negates the enemy screening to an extend, which means that my torpedoes can hit his capitals even through 100% screening.


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So while I was slowly grinding my way across China, I also decided on my buildup strategy:


  • No new battleships, since they eat up a lot of fuel and I have enough to cover my carriers. However, I did later decide to build at least one Yamato-class as an insurance against Niall developing modern battleships.

  • A force of 4 light carriers. Japan starts with two (Ryujo and returning fan favourite Hosho), with two Zuhio class building. While these only carry 40 planes each, they will be used to provide cover for operations in and around the Dutch East Indies.

  • A force of 4 fleet carriers, with another force of 4 joining later. Akagi and Kaga will be joined by 2 more Soryu class carriers and form the main strike force in the Central Pacific.

  • A heavy emphasis on air defense and torpedoes. After researching dual purpose main armaments, I design a new destroyer class with improved AA and better torpedo armament. These are joined by a quartet of light torpedo cruisers from the Japanese focus.

  • Lots and lots of Naval Bombers to damage the enemy during the approach and pick off stragglers. Once the battle is fought, his damaged ships would likely try and find a close naval base for repairs, so having naval bombers ready to attack them in port would let me finish them off.

  • Once I identified the fleet’s weakness in defense against destroyers, I also designed a version of the Mogami Class heavy cruisers dedicated to light gun support. I built another 4 of these.

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The fleet’s main objective, however, is to provide support for landings to seize resource rich areas in the Dutch East Indies. To protect the sea lanes to and from these islands, I will need to secure the Philippines, and that is where things get a little dicey.


While I have little doubt that my forces can take over Sumatra, Java and Borneo, Malaya might be a tough nut to crack, and I know that Niall has already started to fortify the Philippines. I have researched amphibious armor well in advance and with China now pacified, I start to turn up production in an attempt to give my marines a bit more punch and hopefully allow me to seize a foothold even against heavy opposition.

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Thinking ahead, I also research improved naval bombers and the next generation of carrier planes. Once my main objectives are secured, I will use swarms of naval bombers to hold them down while I move my fleets to stage two and take on Australia.


To give myself some more time to buildup, I delay my attack on the US until early 1942. This allows me to form a second strike force of two fleet carriers (Shokaku and Zuikaku, both repeat Soryus as I was unable to scrape together enough XP to design an upgraded carrier).


The first battles are very encouraging. Whenever my patrols find one of his scouting units, my strike fleets sortie and make short work of them, Niall’s vaunted Destroyer swarms being no match for my upgraded cruisers and destroyers. I am somewhat confident that I can attrit his screening forces faster than he can replace them, which would eventually force his fleet to remain in port or eat absurd numbers of torpedoes.

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Things quickly turn a little chaotic as my strike fleets and patrols intercept a number of troop convoys. While I first thought that these were going to the Philippines, they instead turn out to be trying to seize islands in the Central Pacific. Things don’t go well for him, as he has decided to keep his battleships and carriers on strike duty instead of covering his invasion convoys. Several divisions are effectively destroyed at sea, and the remains fail to gain any footholds.


At the same time, my invasions in the DEI, supported by the old battleships Ise and Hyuga, have run into stiff opposition while attempting to land in Borneo. I shift some tactical bombers into the theater to help break the stalemate, and we are starting to make progress. The two-pronged assault succeeds in establishing a foothold, but it is a reminder that Niall has not been idle and is ready to fight for every inch of ground in this vital area.

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While my marines still struggle to make landfall in the Philippines, a bigger drama unfolds in the Bismarck Sea. Niall has finally unleashed his main strike force, after one of his patrols found my carrier fleet.


The Battle of the Bismarck Sea does not go particularly well for the Imperial Navy. With several battleships detached for minor repairs, the US Navy breaks through my screening units and manages to do an end run on my carriers, sinking all four for no capital ship loses on their side. The survivors straggle home, many ships badly damaged during the ferocious engagement as my battle line attempted to screen against the full might of the US battlefleet.

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However, Niall’s victory has come at a steep cost. Most of his battlefleet is badly damaged, and he has nothing to follow his success up with. More than that, I still have 6 carriers in reserve (2 fleet, 4 light), and several hundred naval bombers scouring the Bismarck Sea means that he has to risk his battleships again to sail them to safer harbours for repairs. Several of them take further damage as they retreat, many of them out of the battle for almost a year.

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While Niall has blunted my offensive power quite severely, he has nothing to interfere with in my operations in the DEI, which were the main objective. Trying to use the Philippines as an unsinkable aircraft carrier has become next to impossible as trying to supply it with fuel would cost him too many convoys and tank his war support. The Japanese conquest of the southern resource area won’t quite be the lightning strike it was in history, but it is as inevitable as the rising of the sun.

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With hindsight, my performance in the naval war thus far comes down to:

  • Lack of radar allowing Niall to get the drop on me in a critical moment

  • Lack of training due to fuel concerns

  • Insufficient coverage of the seazones with naval bombers failing to disrupt the enemy on the approach

  • Not enough screening vessels to protect my carriers against his battle fleet. Although Yamato sunk several ships and survived to fight another day, spending the same amount of 3 heavy cruisers would likely have yielded better results

  • Good performance of my light forces when engaged on equal terms

That is all for today. Tune in at 1600 CET for another stream with an indepth look at fuel.
 
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Very, very unlikely.

They might do ok against a third world country like Somalia, but against any remotely modernized opponent all a battleship would be is very, very, very costly scrap metal.
I didn't say a battleship.
 
I didn't say a battleship.
Very true and technically a Battleship could work in the modern world if given the right weapons and put at the right budget.
 
Does this mean Japan will get a boost to it's dockyards and steel production to compensate? If they're going to essentially be giving the US a boost to it's fleet, obviously Japan needs compensation as well or the Pacific will be an even bigger joke than it already is.

Japan is already fairly strong. Japan gets a 20% sortie efficiency national spirit and is one of the only countries to get a starter admiral with the carrier trait, as well as ministers with strong carrier skills. Japan is built to have the strongest carriers in the world, which is a huge plus in the current carrier meta which heavily leans towards quality over quantity, due to the carrier stacking penalty.

Still, I do have some complaints about Japan.

- Japan gets zero CV technology bonuses, and zero naval experience from its focus tree. I mean, I can understand having weaker technology and naval experience because of the spirit, but this is a bit too extreme. My view on this may change depending on how badly the England/US trees have their technology bonuses/free naval experience nerfed.
- Japan has no decent historical expansion options. The DEI has a pittance of oil, even if you develop the provinces. Ironically you are massively pressured to go ahistorical and hit the Soviet Union, because that is the only Japanese neighbor with good resources.
- National Defense State is terrible. It enacts a law that is worse than the previous law. Give it -5% consumer goods national spirit or something like the Manchukuo one. At least that gives you a late game option to counteract the Zaibatsu 5% consumer goods penalty.
 
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Thus, in the modern context, building a battleship, even to carry missiles and most definitely to carry guns, would only make sense if anti-aircraft and anti-missile defense made it such that gunfire became an important ship-to-ship weapon again.

There are no weapons systems that can replace battleships as fire support ships of that caliber, which is probably why the US kept some for as long as they did: the USS Iowa and USS Wisconsin were stricken from the US Naval Vessel Register in 2006 and as late as 2010 the US Navy still listed one battleship in reserve, though no longer by 2014.

From Wiki: "The U.S. Marine Corps believes that the current naval surface fire support gun and missile programs will not be able to provide adequate fire support for an amphibious assault or onshore operations.[91][92]".
 
There are no weapons systems that can replace battleships as fire support ships of that caliber, which is probably why the US kept some for as long as they did: the USS Iowa and USS Wisconsin were stricken from the US Naval Vessel Register in 2006 and as late as 2010 the US Navy still listed one battleship in reserve, though no longer by 2014.

From Wiki: "The U.S. Marine Corps believes that the current naval surface fire support gun and missile programs will not be able to provide adequate fire support for an amphibious assault or onshore operations.[91][92]".

This is true, but that's because, iirc (most of my naval reading is about WW2 and earlier, although I do read some modern stuff as well) the largest gun afloat in the USN is a 127mm weapon. There's a lot of room between the 5" in service and a BB-calibre weapon and, if fire support is the only purpose of the gun, there's also no need for a battleship-style deployment - something more akin to the British WW2 monitors would likely be a far more efficient way of going about adding that capability to the fleet. However, if you look through the links you've posted there and give this a read, you'll see the largest calibre under consideration was 203mm (8 inches), not a BB-size gun (and in the end the navy considered a long 155mm weapon the best fit for what it wanted).

Might be worth not going too far down this track in the DD thread though - maybe carry on the 'do BBs still have a role today' in another part of the forums if there's an interest in going down that path?
 
I agree there as a historical RTS game without Pearl Harbor is no historical RTS game.
Especially with the new naval mechanics it makes no sense. Most of those ships that were put out of service by Pearl Harbor were eventually repaired and contributed to the war effort. Just make it an event that damages those battleships so much that they're unusable for a few years, that way it's realistic and the player doesn't just lose a few capital ships on the completion of a Japanese focus.
Of course then you'd also need to incentivize the player to actually base those ships in Pearl Harbor. Maybe use the new senate mechanic, so you only get support from Hawaii if you have enough capital ships there...
 
Might be worth not going too far down this track in the DD thread though - maybe carry on the 'do BBs still have a role today' in another part of the forums if there's an interest in going down that path?

Arleigh Burke third flight displacement; 9800 tons
Faragut class displacement; 1365 tons

Comparing WW2 era ships to modern ships is kinda silly if you stick to designators.
Colorado class was 33,100 tons by comparison.
Cassablance Class CVE was, fully loaded, 10,902 tons
 
Edit: this is response to @Vanadium23's post, a few posts above mine.

Very undecided on Pearl Harbour. The senate idea I actually like, but I dislike the idea of giving the Japanese player "free kills" in the form of a decision.

Also consider this isn't a railroaded game, and Pearl Harbour takes place nearly six years after game start. Trying to make specific historical battles happen this late in the game is always going to be tricky. Instead, you're going to have memorable battles and events that didn't take place historically, but which shape your particular campaign.

Now, if either the devs or modders made a Day of infamy bookmark where the US started with crippled ships at Pearl and a Japanese task force close by, that would be a different story, of course.
 
Actually, what would also be interesting would be a US anti-sabotage decision that could be activated for, say, six months at a time, and gave higher encryption and perhaps other bonuses, at the cost of more vulnerable ships, planes, and facilities. This would simulate parking planes out in the open, locking away ammo for AA guns, etc.

(As an aside, this is why I keep asking for readiness/mobilisation levels, covert justification attempts, and surprise attacks to be added to the game).
 
Also consider this isn't a railroaded game, and Pearl Harbour takes place nearly six years after game start. Trying to make specific historical battles happen this late in the game is always going to be tricky. Instead, you're going to have memorable battles and events that didn't take place historically, but which shape your particular campaign.

Japanese and American entries to the war already coincide in competitive MP (1941) and should coincide in SP with historical focuses on, provided the player is willing to impose some house rules on himself to avoid silliness like joining in 1939 as the US. So for historical play creating some kind of PH strike shouldn't be that difficult. All the previous HoI games had some form of it, even if it wasn't always all that well implemented.

For ahistorical play (and by that I mean total fantasy like Japan attacking the Allies in '39, i.e. not smaller scale deviancy from history), you can still leave the option for a PH strike in, but have it be less of a mandatory way to enter Japan and the US into the war.
 
This was played as an MP game between me and Niall (@Ceebie), with me defending the Empire of Japan’s honor against Niall’s filthy American imperialists.

Nice idea for a DD and a very interesting read!

As much as I appreciate this DD, I'd rather have seen the AAR from an SP point of view. Since I'm not an MP player, I'm more interested in how AI deals with the new mechanics. I think I'm probably not the only one with that.

Anyways, thanks! :)
 
My humble opinion on "Pearl Harbor":

Pearl Harbor should be a Decision that Japan can take, with ships stationed being temporarily damaged. If Japan players choose Historical Focus option, damage is limited to just any warships stationed there. Priority being heavy warships. There's also a random (tiny) chance that a "3rd attack wave" could have been taken, with more damage on fuel depots and dockyards in Hawaii, and possibly a temporary decrease on decryption (to simulate an attack on the US Pacific Fleet Headquarters itself and the naval code readers)

Unlockable only when taking the "Secure the Philippines" Focus. Naturally, this comes at a cost of increased War Support for the Americans (historically). Much more when the 3rd Attack Wave happens.

To those wondering why I suggest this, I am simply in favor of giving more perks for the IJN despite the main focus on the USA and UK. This IS a naval-themed DLC, after all. Without the "Pearl Harbor Gambit" Focus, I honestly think Japan is already toast to begin with. At the very least, the unlocked decision should give Japan an early-game historical advantage. They can be pushed back, however, as Japanese ship losses become too much, while American industrial production and decryption techniques improve massively. (Historically)

I could argue a similar approach for the Asiatic Fleet in Manila, the British Far Eastern Fleet in Singapore, or even the Soviet Pacific Fleet in Vladivostok. After all, the Japanese have a precedent for surprise attacks. *cough* Port Arthur *cough*

I dunno, just my 2 cents. :)
 
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Hm, on the first sight, I don't se fire range in the stats... or was that changed and covered in earlier dev diaries? I browsed back to some of them but can't find anything quickly...

From what I can remember from previous DDs

Light guns can target things in the first rank.
Heavy guns can target things in the second rank
Torpedoes can target things in the third rank (depending on level of cover supplied by first two ranks - 4:1:1 for perfect cover I think).

Transports and Carriers go in the third ranks, heavies in the second, screens in the first. (as each rank gets cleared it allows units to attack the one behind - so light guns can sink transports only so long as they have no escorts IIRC)

I'm not sure there is range beyond that. It's more regimented than previously but at least allows fleets to act as fleets rather than individual ships.
 
Japanese and American entries to the war already coincide in competitive MP (1941) and should coincide in SP with historical focuses on, provided the player is willing to impose some house rules on himself to avoid silliness like joining in 1939 as the US. So for historical play creating some kind of PH strike shouldn't be that difficult. All the previous HoI games had some form of it, even if it wasn't always all that well implemented.

For ahistorical play (and by that I mean total fantasy like Japan attacking the Allies in '39, i.e. not smaller scale deviancy from history), you can still leave the option for a PH strike in, but have it be less of a mandatory way to enter Japan and the US into the war.
Good points all.
 
Hm, on the first sight, I don't se fire range in the stats... or was that changed and covered in earlier dev diaries? I browsed back to some of them but can't find anything quickly...
Fire range is now: light guns hit first layer of enemy ships, heavy guns hit second layer, aircraft hit all layers, subs can hit anywhere with declining chances of success.