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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!).

Screenshot_8.jpg


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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Comparing this DLC with the stuff you guys did in the first one is totally night and day.

Super improvement, especially with listening to the community and taking the good ideas and filtering out the bad ones and the ones that would be just too much work to develop.

Excellent logic, and fantastic game plan. Bravo guys.
 
All four of those examples were converted on the stocks, though, so they didn't need to 'break down' the BB/BC parts first iirc (and I could be wrong here), and things like machinery and boiler uptakes could be arranged early on in a way that was friendly for carrier operations. It'd be a larger job taking an already-built ship, breaking it down, re-arranging the necessary parts and then building it back up again.



It isn't necessarily (although I'd imagine in many cases for BBs it would have been), but it was in this case :). If you go to this site, and scroll down, you'll see for February 1942 (if you want to look at the source it's probably easiest to grab some of the text from the quote below and search on the page):



In this case, they also replaced some of the 16in barrels with Mk I rifling with 16in barrels with Mk II rifling (the three in A turret I think, but I'd need to look up the details - Rodney and Nelson both had periods where they had barrels with two types of rifling concurrently, making for ever-so-slightly different ballistic characteristics (although it apparently wasn't a huge problem, and the characteristics of the two types of rifling converged with wear making things better over time)).

More gameplay-focussed, the whole 'where can a ship refit/repair' is a tricky one, as a drydock was different to having a large naval industry. Singapore had one of the largest drydocks in the southern hemisphere at one point, but as best I understand it at no point had a shipbuilding industry that was anywhere near capable of building a capital ship from scratch. Sydney, similarly, by 1945 could do repairs to the BPF capitals and fleet carriers, but was a long way from being able to build it's own. Malta's another example of a place with excellent repair facilities but limited shipbuilding capability

It gets confused even further with floating docks, which both the US and UK used (the UK kept one at Gibraltar, iirc, although that's a particularly fuzzy memory). Both Valiant and Queen Elizabeth took advantage of Admiralty Floating Dock 5 at Alexandria after their close encounters with Italian frogman, for example (but were not fully repaired there).

From a gameplay perspective, repairing a capital ship in a smaller port could be seen as the use of a floating dock or similar. It's not perfect (for serious repairs, they'd usually be patched up in the floating dock then sent to somewhere with more substantial repair facilities), but at the end of the day there needs to be some balance between detail and gameplay, and given the amount of repair work that was done in ports in states with no significant shipbuilding capability, I personally don't feel its a bad simplification - but that's just my 2 cents, you've got a case as well and should pursue it with appropriate vigour :).


Axe Lexington was 25% complete when converted, they kept her belt and her boilers. This suggests that in effect most of the ship was in place as a battlecruiser as a lot of the work in construction is doing the final fittings and turret intallation.
 
Axe Lexington was 25% complete when converted, they kept her belt and her boilers. This suggests that in effect most of the ship was in place as a battlecruiser as a lot of the work in construction is doing the final fittings and turret intallation.

That sounds reasonable enough - although I'd still argue it'd be easier to turn a 25% completed ship into a carrier than a 100% completed ship - but I could well be wrong, I've never done either before myself :).
 
All four of those examples were converted on the stocks, though, so they didn't need to 'break down' the BB/BC parts first iirc (and I could be wrong here), and things like machinery and boiler uptakes could be arranged early on in a way that was friendly for carrier operations. It'd be a larger job taking an already-built ship, breaking it down, re-arranging the necessary parts and then building it back up again.



It isn't necessarily (although I'd imagine in many cases for BBs it would have been), but it was in this case :). If you go to this site, and scroll down, you'll see for February 1942 (if you want to look at the source it's probably easiest to grab some of the text from the quote below and search on the page):



In this case, they also replaced some of the 16in barrels with Mk I rifling with 16in barrels with Mk II rifling (the three in A turret I think, but I'd need to look up the details - Rodney and Nelson both had periods where they had barrels with two types of rifling concurrently, making for ever-so-slightly different ballistic characteristics (although it apparently wasn't a huge problem, and the characteristics of the two types of rifling converged with wear making things better over time)).

More gameplay-focussed, the whole 'where can a ship refit/repair' is a tricky one, as a drydock was different to having a large naval industry. Singapore had one of the largest drydocks in the southern hemisphere at one point, but as best I understand it at no point had a shipbuilding industry that was anywhere near capable of building a capital ship from scratch. Sydney, similarly, by 1945 could do repairs to the BPF capitals and fleet carriers, but was a long way from being able to build it's own. Malta's another example of a place with excellent repair facilities but limited shipbuilding capability

It gets confused even further with floating docks, which both the US and UK used (the UK kept one at Gibraltar, iirc, although that's a particularly fuzzy memory). Both Valiant and Queen Elizabeth took advantage of Admiralty Floating Dock 5 at Alexandria after their close encounters with Italian frogman, for example (but were not fully repaired there).

From a gameplay perspective, repairing a capital ship in a smaller port could be seen as the use of a floating dock or similar. It's not perfect (for serious repairs, they'd usually be patched up in the floating dock then sent to somewhere with more substantial repair facilities), but at the end of the day there needs to be some balance between detail and gameplay, and given the amount of repair work that was done in ports in states with no significant shipbuilding capability, I personally don't feel its a bad simplification - but that's just my 2 cents, you've got a case as well and should pursue it with appropriate vigour :).

A good post and very reasonable points.

We already have Naval bases in game, which should be able to patch up battle damage of course, though I'd argue not repair any of the new critical hits. Or refit of course.

For instance if HMS Rodney took a main armament crit near Singapore then it isn't unreasonable to expect her to have to return to the UK as her turrets alone were well north of 1000 tonnes and not produced there. Or the Bismark a crit to her steering... She could get reorged in a piddly random naval base but to fix the crit would need proper facilities... Which would then make those facilities a strategic target, and a scarce resource, and make her vulnerable whilst she tried to return to a properly equipped yard. HMS Warspite for instance was never fully repaired after the Fritz X attack, presumably as the dockyards were better used for new builds.

Would also add some interesting choices regarding refit or new build. And the strategic locations of such industry. As the UK for instance I could build up Alex or Singapore to fully service Capitals, though I then risk gifting this industry and possibly any ships under repair there, should I be careless enough to lose the province.

Similarly sending lone Capitals to raid far from their support infrastructure might be profitable, though if damaged you'd need some diplomatic clout to get a friendly country to help out.

I'm not just talking about battle damage here either. What might happen if the Prince of Wales took a non combat crit to her radar for instance, maybe a more minor one to her AAA too, which Singapore was unable to repair? Or US carriers taking crits to their flight decks and facing a bit of a trek to find somewhere capable of fixing them? Better to patch up your tier 1 carriers or devote that 5* yard to finishing new build tier 3s? Or a bit of both?

Say my SHBB took a crit to it's secondaries.. Well I would need a yard at least capable of building heavy cruisers as they were just Mogami turrets.

Say as the UK I have my starting 19 dockyards and haven't built more, maybe only 10 of that total are in two provinces of 5 each allowing me to either build two Capitals at a time or refit existing capitals.

It's just a suggestion, and not one that I am wedded to, though I do feel that something along these lines would add a great deal of depth and realism to the gameplay which currently sees complicated bits of kit being used thousands of miles from any supporting infrastructure without any real consequences.
 
I havn't read through the whole thread, and therefore don't no whether this has allready been brought up. A large standing fleet can eat up vast amounts of manpower.
This effect is especially felt by the western democracies in a very harsh way. Britain for instance is very low on manpower at the start of the game in early 1936, and has
a large navy of old ships eating up valuable manpower. I would like to have the option to mothball a ship, and wait and see whether it would be a good idea to reactivate,
scrap, upgrade, lend-lease or to sell it at some point in the future.
 
I've had a change of heart, do this for tanks and planes!
 
Mexico Gameplay!
 
Netherlands When?
 
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

What did they do with the middle turret and its guns?
 
What did they do with the middle turret and its guns?

They removed them. All Guns and Turrets. The Ship got brand new Turrets and Guns cause of the higher caliber and modernized gun technology.
The middle one was removed too, and - as far as I know - they needed its space for a newer generation of engine.
 
Unrelated to the current Dev Diary, but something I noticed with the Mexico playthrough in the latest World War Wednesday: Mexico's Focus Tree got updated where a quite a bit of stuff was rearranged, renamed, and condensed, but the old preview for the Focus Tree is still up in the Mexico Dev Diary. Any chance to for the updated Mexico Focus Tree to be edited in or posted elsewhere?
 
I like this so far.
I understand how complicated putting merchant vessels in game would be just for conversions. So if we wanted to build Canada's 3 Princes, just select the appropriate hull size and throw some weapons on them. Converted merchant vessels were always improvised with no intention of facing the main fleet.

Will old naval guns removed from ships be able to become coastal guns or be assigned to another ship? PofF gets new AA guns so old ones get installed around reserve fuel tanks or turrets from scrapped BB are sent to Dover to keep Calais awake at night.
 
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.
What about ships under repair or even under construction, will they also be captured when the provinces they are in are being overrun by enemy force? If this is true, that definitely will be a cool feature for the game!
 
Will the ship refitting system also be applied to much smaller equipment, like tanks and airplanes, like selecting target equipment in the division equipment/air wing equipment tabs and upgrading to the desired ones? I think the current upgrade systems for land and air equipment are too simple and easy, and employing the new ship refitting system to replace the current land/air upgrade systems would make the land/air upgrade in the game more realistic!