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Hoi4 Dev Diary - Naval Treaties and Ship Refits

Hello, and welcome back to another exciting dev diary about ship design!

As many of you noted last week, ship design in the interwar years was heavily restricted by the Washington Naval Treaty and the First London Naval Treaty. During and after the Great War, naval planners the world over were drawing up plans for new battleships that made use of new technologies, with ever bigger guns requiring ever stronger armor meaning increasingly large ships that were becoming even more expensive. At the same time, Britain and France were at the edge of bankruptcy from the debts they had accumulated during the Great War and could not afford another naval arms race with the fairly untouched nations of Japan and the US.

The result was the Washington Naval Treaty of 1922, which forbade any new battleship construction for a period of 10 years and restricted the maximum size of ships as well as their gun armament. In 1930, the signatories of the Washington Naval Treaty came together and negotiated the London Naval Treaty, which limited the construction of cruisers and stipulated strict restrictions on their size. In early 1936, the London Naval Treaty was up for renegotiation and that, as they say, was when the trouble started.

These restrictions forced the designers of warships in the interwar period to come up with some interesting compromises, and although we can’t possibly model all the interconnected ways in which these restrictions impact design - the Nelson class baffled American designers who were trying to comprehend why the British would build a ship like that - we did want to model some of the impact and also represent the diplomatic effects of the naval treaties.

picture_naval_treaty.jpg


All the signatories of the 1930 London Naval Treaty will start with a national spirit that restricts the maximum cost of their capital ships. As I said last week, we originally played around a bit with tonnage as a restricting value for ship design, and obviously this would have tied in neatly with the Naval treaties, but the design was changed later to instead focus on slots and construction cost. We also thought about simulating the restrictions in gun caliber etc. through restricting modules, but in the end decided against it because it would disincentivize the player to engage with the ship designer - imagine researching a new heavy battery and then finding out that you can’t install it because it would violate the treaty! It still means that in ship design, you can’t just build the best possible ship on day one as the cost restrictions are quite harsh.

treaty_bs.jpg


When you start the game in 1936, you will notice a mission ticking down reminding you that the Second London Naval Conference is currently underway. If you don’t decide to bail, you will automatically sign the Second London Naval Treaty. Bailing from the treaty is at first only available during the London Conference, costs some political power, but less for fascist nations. However, fascist nations can stay in the treaty and later decide to cheat use creative accounting to measure the true displacement of their ships, which means they have reduced restrictions while, presumably, lying through their teeth when asked about the curiously large cruisers they are building (the Head of Ship Design for the Royal Navy during the 1930s once remarked that the other side was either building their ships from cardboard or lying when presented with the official numbers for a new cruiser!).

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Once world tension hits a certain level, the decisions to leave the treaty are once again available for everyone. Should any country have left the treaty, either during the initial conference or afterwards, a timer starts ticking down for the remaining countries that activates the historical “escalator clause”, which will ease the restrictions slightly, allowing even the signatories of the treaty to build more powerful ships. As a fascist country you therefore have an incentive to stay in the treaty, as it will restrict your opponents more than it restricts you while denying them the escalator clause.
escalator_clause_2.jpg

If a country outside the treaty reaches a certain percentage of the British size in capital ships, they can be invited into the treaty. Should the nation decline and continue to expand their navy until near parity, the treaty nations can try to force them to disarm up to 80% of the number of capital ships. A refusal to disarm may lead to war. If a signatory nation exceeds the allocated amount of capital ships, they immediately get a mission to reduce the number of capital ships, at the threat of major stability loss.

So you will probably want to make sure you have the most capable ships you can as you are quite limited in numbers as well as size. One of the more annoying parts of the old variant system was that a capital ship might well be obsolete by the time it hit the waves, with no chance of ever being modernized. It made even less sense in the context of the ship designer, where the upgrades between the ship classes were supposed to be more gradual. Enter the refit feature, which will allow you to upgrade your ships and otherwise tailor them better to your needs as the situation changes - from upgrading the AA on your battleships to removing one of the torpedo sets on your destroyers to make room for more depth charges.
refit.jpg


All modules have a production cost, of course, but in addition they can (and usually do) have a conversion cost as well as a dismantling cost. The conversion cost determines how much it costs to, well, convert that module from another module. This means that it is usually cheaper to upgrade, say, Anti-Air from Level 1 to Level 2 than it is to rip out the rear turret and put some AA in there. There are some exceptions to this, mostly for historical immersion: upgrading the engines is a major effort that historically required very long yard times (you basically have to cut open the hull to get the old engines out and get the new engines in, then patch it up), so it is almost always not worth it (upgrading the engines on an old battleship gets you about 2 knots of speed at the cost of a modern light cruiser), but we wanted to give you the option. As a general rule, it is never cheaper to build a lower tier and then refit to something more modern.
picture_refit_aa.jpg

If there is no specific conversion cost scripted in, you have to pay the dismantling cost for the old module and the construction cost of the new module. Modders will be pleased to hear that you can script in dismantling resource costs so you can actually gain resources back from scrapping certain components.
C_class_refit.jpg

To refit a ship, you create a variant and then select the ship you want to refit, then order it to refit to that variant. The ship will detach to go to the nearest naval base and become an item in the production queue with a few special mechanics: because it is technically still on the map, it can be bombed and damaged, which reduces build progress. If the province it is in is overrun by the enemy, it will be captured and may end up serving your enemies.
c_class_carrier_refit.jpg

You usually can’t refit between ship hulls (so a 1936 destroyer can only be refit to other 1936 destroyer variants), but otherwise you have a lot of freedom on what you can refit into what and are only really restricted by cost (for historical examples, see the Japanese Mogami class becoming heavy cruisers after being built as light cruisers). A special case are carriers, where cruiser and battleship hulls can be converted into certain carrier hulls. These are generally not as capable as purpose-built carriers, but if you have some old ships lying around…
picture_carrier_conversion_finished.jpg

Lastly, some of you have noticed that one of the German ships we showed last week looked a little different. The Admiral Scheer is at game start the Pride of the Fleet for Germany, giving Germany a small (5%) war support bonus and the ship itself some bonuses to defense against critical hits (ahistoric in case of HMS Hood, certainly) and bonuses to experience gain. It also has some interesting synergy with admirals that have the Media Personality trait: they will gain bonuses when commanding a fleet with a Pride of the Fleet in it.
Germany_panzerschiff.jpg

Assigning a ship as Pride of the Fleet is free if you don’t have one already. Changing your Pride of the Fleet costs some political power (and presumably makes the crew of the old one very sad, you monster). You can only make a capital ship the Pride of the Fleet, and you should choose wisely - losing it gives a painful penalty to war support for a while.
potf.jpg

That’s all for today, remember to tune in at 1600 hours for our stream, when we will show off some gameplay for Mexico!

Rejected Titles:

With a large enough pocket, every battleship is a pocket battleship

The Italians actually were building their cruisers out of cardboard as it turned out

What really is a heavy cruiser, anyway?

Get your discount cruisers

You can now play with your LEGO-ships even after you have built them!

Personally I think armor is overrated anyway

The C-Class Carrier Conversion has nothing on the T-Type Torpedo Transformation or the M-Model Machinegun Makeover!
 
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Everything here looks great, however how will the LNT interact with the war?

Afterall, the participants hardly cared about the limits and stipulations when there were enemy navies to be sunk.

The treaty goes up in flames if a signatory nation is at war with another major.

How well does this work for the largest (non-conversion) rebuilds in modern history - the Conte di Cavour and Caio Duilio-class battleships, which went from 13x305mm guns and 21.5 knots to 10x320mm guns and 27~28 knots? The cost was, of course, astronomical for a rebuild; but it worked within the limits of the treaties.

They went from this:
Profilo_e_pianta_Duilio.jpg

to this:
Profilo_e_pianta_Duilio_ricostruito.jpg

The refit itself should work fine, the interaction with the treaties is a bit more complicated but with the cheating decision should be possible.
 
BTW what's the justification for light cruisers being converted into carriers - is this to represent the small escort carriers that were spammed towards the end of the war? It seems a small hull for a carrier. Is there something to stop most/all of those old C-class cruisers being converted?

It's a very expensive refit for a mediocre carrier?
 
Is the AI actually going to build carrier planes now? It's a big issue in SP.
 
That looks really really great.

So let me get this straight, if someone leaves the treaty every one else gets into a one-year timer to leave the treaty as well?

Also, have you tinkered with Naval Experience generation? I'm wondering with all these new goodies we're getting if the costs of designing and upgrading under the new system more or less fit or not with the new system or whether more naval exp. will be needed to keep up.

Training for ships and air wings for XP are also supposed to be introduced this DLC
 
Any penalty to stationing the Pride in port during the entire war to gain the bonus without risks? (apart from losing the synergy with the admirals)
 
Any penalty to stationing the Pride in port during the entire war to gain the bonus without risks? (apart from losing the synergy with the admirals)
The shame of cowardice!
 
Hi Archangel, this looks very interesting, but I've 3 questions regarding the London Naval Treaty mechanics that I hope you'll be able to answer.

1. You note that once a non-signatory reaches a certain percentage of total number of British capital ships they can be invited to join. If they decline and continue to build up their navy to near parity, they can be attacked. How does this work if Britain suffers heavy losses during the war? Reading what you wrote suggests that the more losses Britain takes, the more nations could be invited to the Treaty - and could potentially see themselves declared on if they refuse and Britain takes even more losses. Is that a proper reading of how it works and would the AI start inviting (lots) of nations to become signatories in such a case?

2. Would it be fair to presume that capital ships are weighted equally in this scenario? Meaning that for the purposes of the calculation of the relevant percentage a heavy cruiser has the same value as a battleship or a carrier?

3. Okay, so this one isn't really about the London Naval Treaty, but about the 1935 Anglo-German Naval Agreement. Given that it's not mentioned, is it fair to assume that this rather similar treaty is not represented in game? I would assume that it's not and that the option to invite countries into the London Naval Treaty is partly there to also allow for a way to entangle a(n imperial) Germany into the Treaty if it chooses to significantly build up its surface fleet.

Thanks!
 
Looks great!

By the way, does anyone know if there's a post kicking around that has a list of links to every dev diary? I thought there was one, but I can't seem to find it.
 
Not right now, but we might add some decisions to celebrate its successes if it sinks an enemy.
Can you make convoys more valuable? They really ought to cost more and require manpower - they were super valuable historically (especially to the UK) and couldn't just be spammed as they are now. A slight rework so that convoys are generally fewer in number but cost more and are harder to replace would add a lot to the game, and make convoy raiding more useful.
 
Hi Archangel, this looks very interesting, but I've 3 questions regarding the London Naval Treaty mechanics that I hope you'll be able to answer.

1. You note that once a non-signatory reaches a certain percentage of total number of British capital ships they can be invited to join. If they decline and continue to build up their navy to near parity, they can be attacked. How does this work if Britain suffers heavy losses during the war? Reading what you wrote suggests that the more losses Britain takes, the more nations could be invited to the Treaty - and could potentially see themselves declared on if they refuse and Britain takes even more losses. Is that a proper reading of how it works and would the AI start inviting (lots) of nations to become signatories in such a case?

If Britain is at war with a nation that can sink most of its fleet, the treaty goes away automatically.

2. Would it be fair to presume that capital ships are weighted equally in this scenario? Meaning that for the purposes of the calculation of the relevant percentage a heavy cruiser has the same value as a battleship or a carrier?

They aren't right now, with cruisers being weighed less than battleships, but that might get a little too confusing so may be changed before release.

3. Okay, so this one isn't really about the London Naval Treaty, but about the 1935 Anglo-German Naval Agreement. Given that it's not mentioned, is it fair to assume that this rather similar treaty is not represented in game? I would assume that it's not and that the option to invite countries into the London Naval Treaty is partly there to also allow for a way to entangle a(n imperial) Germany into the Treaty if it chooses to significantly build up its surface fleet.

Thanks!

The system could be applied to the Anglo-German naval treaty but isn't currently because it overlaps so much with the LNT.
 
Hi Archangel, this looks very interesting, but I've 3 questions regarding the London Naval Treaty mechanics that I hope you'll be able to answer.

1. You note that once a non-signatory reaches a certain percentage of total number of British capital ships they can be invited to join. If they decline and continue to build up their navy to near parity, they can be attacked. How does this work if Britain suffers heavy losses during the war? Reading what you wrote suggests that the more losses Britain takes, the more nations could be invited to the Treaty - and could potentially see themselves declared on if they refuse and Britain takes even more losses. Is that a proper reading of how it works and would the AI start inviting (lots) of nations to become signatories in such a case?

War between two signatories ends it but the question is what if a player UK scraps most of the fleet for whatever reason
 
In which way are pre 1918 ships represented within the new system? Are m1936 hulls still the oldest type?
Recently I heard an interesting discussion of a marine and a historian on youtube about hoi4, where they basically said that the really old ships weren't adequately represented within the old navy system. They talk about many other aspects of the game as well, mainly regarding its realism.
If someone is interested in such things the talk is certainly worth your time:
 
"Penalty when sunk" sounds a bit ominous :p .

This looks great for immersion, though .