ship upgrades

[IrrationalDuck]

as the title says. i havnt been able to figure out how to replace my old designs with newer better variants automaticly like it does with aircraft for example, anyone know how to get it to autoreplace old designs without having to decommision and jsut build new ones over and over?

[Radioactive]

I am pretty sure ships are not supposed to auto-replace.

You can convert certain ship types into other types -like big capitals into light/escort carriers- as happened historically sometimes, but they don't directly "upgrade" your older battleship into a new type.

I too wish there was an AI automation for assisting with replacement of ships -especially subs. It'd be fine if they just literally called the ships to port when one is ready, decommissioned the old one and added the new one to that fleet, but AFAIK that's not in the game.

Arguably, it's about player's convenience. I don't think it usually makes much sense to decommission ships early in terms of strategy. Figures it is better to just make them fight until they are sunk.

[IrrationalDuck]

that sucks alot, its a real pain in the ass to muster out all my old ♥♥♥♥♥♥♥♥ destroyers that have no range or ability and jsutm ake all new ones

[The Neck Chop]

yeah i hope they do ship upgrading like they do with all other types of equipment. you can even upgrade planes at the moment so i dont see why they wouldnt do this for ships because it makes sense if you build more ships of a newer design it will faze out the old design, just like it does with everything else you produce.

[Kompromised]

So at the moment there is no way to replace older ships with newer ship designs or better ship varients?

[A Bat From Wuhan]

I also think it's supposed to represent how ships were generally treated in Real Life. You can replace rifles and tanks with a new version every year or two. But ships are a real investement, most of the US Battleships used in WWII were built during World War I or the early 20's, it's not a real quick process of "phasing out" older models of ships. Sure it does happen eventually, and those old ships are taken out of combat, but even then they are still used as transports or hospital ships.

[Erik_Rex]

Originally posted by Officer Judy Hopps:

I also think it's supposed to represent how ships were generally treated in Real Life. You can replace rifles and tanks with a new version every year or two. But ships are a real investement, most of the US Battleships used in WWII were built during World War I or the early 20's, it's not a real quick process of "phasing out" older models of ships. Sure it does happen eventually, and those old ships are taken out of combat, but even then they are still used as transports or hospital ships.

indeed, however, it could be nice to see a mechanic to upgrade ships to a later model or atleast varient of the same ships as all ww1 ships was retrofitted to be more effective in ww2. Though I guess most ships were changed before ww2 and not during, though I guess some were that aswell

[Texonater]

In HOI3, the only parts of Ships that would be upgraded were the AA guns. Not suprised they stuck with that formula. If you want to be a naval power, you need to do a significant amount of planning to research and then manufacture the designs you want. Each ship is a significant investment.

[[NL]Ibahalii]

Originally posted by Rexxar:

indeed, however, it could be nice to see a mechanic to upgrade ships to a later model or atleast varient of the same ships as all ww1 ships was retrofitted to be more effective in ww2. Though I guess most ships were changed before ww2 and not during, though I guess some were that aswell

only ships i can remember that went under retro fitting before and during wars where passenger/cargo ships. that would be converted into CV types. like
- Taiyo[www.combinedfleet.com]

Akagi(was planned as a cruiser)
Akagi CV[en.wikipedia.org]

- HMS Argus[en.wikipedia.org]

and many many more.

Tho in WW1`they used dreadnaughts. and even tho the model of the Battleship was born from dreadnaughts, they aren't actually a upgrade of them.

i believe(memory may fail me here so if somebody knows, please correct).
The britsh Battle-cruisers where a remaining relic of the WW1 days, that where brought back to port and underwent retro fitting of times ranging between 2 to 7years per ship.
Many where actually scrapped while retro fitted and 'rebuild' as (then) modern Battle-cruisers.

The only country that i know of that was still using WW1 ships in WW2(start of) where the Dutch.
De zeven Provinciën[en.wikipedia.org]
It never underwent retro fitting and stayed as a coastal defence ship of the indonesia realm.

After it was sunk it was 'rebuild' after the war into a new modern cruiser type.

So i can see why Paradox went in this direction with it all.
AA-guns could be upgraded, Main-cannons even(if enough time). but to change the armor on the hull, the water-line protection, deck armor, Boiler rooms, propshafts etc...would be virtually imposible.

Only ship i know of that had that much work done was the Tirpitz or the Bismark.
One of the 2 ships took a major hit right after they where sailed out to join the war. and was sailed straight back into the dockyard. the retrofitting to over 2years(before the allies where bombing Germany). as soon as the bombing started they just stopped, finnished the ship up, and basicly said 'that will do' and send her on the way to a final resting place(not intentional, its just that the Brits and USA really wanted to see those ships out of comision).

[Erik_Rex]

Originally posted by Ibahalii:

Originally posted by Rexxar:

indeed, however, it could be nice to see a mechanic to upgrade ships to a later model or atleast varient of the same ships as all ww1 ships was retrofitted to be more effective in ww2. Though I guess most ships were changed before ww2 and not during, though I guess some were that aswell

only ships i can remember that went under retro fitting before and during wars where passenger/cargo ships. that would be converted into CV types. like
- Taiyo[www.combinedfleet.com]

Akagi(was planned as a cruiser)
Akagi CV[en.wikipedia.org]

- HMS Argus[en.wikipedia.org]

and many many more.

Tho in WW1`they used dreadnaughts. and even tho the model of the Battleship was born from dreadnaughts, they aren't actually a upgrade of them.

i believe(memory may fail me here so if somebody knows, please correct).
The britsh Battle-cruisers where a remaining relic of the WW1 days, that where brought back to port and underwent retro fitting of times ranging between 2 to 7years per ship.
Many where actually scrapped while retro fitted and 'rebuild' as (then) modern Battle-cruisers.

The only country that i know of that was still using WW1 ships in WW2(start of) where the Dutch.
De zeven Provinciën[en.wikipedia.org]
It never underwent retro fitting and stayed as a coastal defence ship of the indonesia realm.

After it was sunk it was 'rebuild' after the war into a new modern cruiser type.

So i can see why Paradox went in this direction with it all.
AA-guns could be upgraded, Main-cannons even(if enough time). but to change the armor on the hull, the water-line protection, deck armor, Boiler rooms, propshafts etc...would be virtually imposible.

Only ship i know of that had that much work done was the Tirpitz or the Bismark.
One of the 2 ships took a major hit right after they where sailed out to join the war. and was sailed straight back into the dockyard. the retrofitting to over 2years(before the allies where bombing Germany). as soon as the bombing started they just stopped, finnished the ship up, and basicly said 'that will do' and send her on the way to a final resting place(not intentional, its just that the Brits and USA really wanted to see those ships out of comision).

The Japanese did alot of changes and upgrades to thir ships after ww1,
https://en.wikipedia.org/wiki/Kong%C5%8D-class_battlecruiser
None of the upgrades are massive, but in terms of the kongo, it was fitted with bigger guns, more armor and a better engine to make it go from a battle cruiser to a battle ship.

and again, most ships from ww1 got some upgrade, if nothing more than better guns or torpedos fitted, it is still an uppgrade, and it could be in the game, but I am not sure how worth it would be to use docks to refitt existing ships rather than build new ones, could still be interesting to see though.

[[NL]Ibahalii]

Originally posted by Rexxar:

The Japanese did alot of changes and upgrades to thir ships after ww1,
https://en.wikipedia.org/wiki/Kong%C5%8D-class_battlecruiser
None of the upgrades are massive, but in terms of the kongo, it was fitted with bigger guns, more armor and a better engine to make it go from a battle cruiser to a battle ship.

and again, most ships from ww1 got some upgrade, if nothing more than better guns or torpedos fitted, it is still an uppgrade, and it could be in the game, but I am not sure how worth it would be to use docks to refitt existing ships rather than build new ones, could still be interesting to see though.

yes cruiser to basicly bigger cruiser(thus battlecruiser) that is well known.
90% of the Royal navy is that basicly...
in terms of the Kongo BC to BB, that is much more rare. and i am(to be quite fair) suppriced to see it surviving the upgrade.

As to upgrade a BC to a BB is no small feet. (if it was) to be a true battleship the hull, boilers, propshafts, rudders, water-line protection etc all would need to have been changed.
but as the article also states.
it got done in the 20's, and as soon as it was done(due to the london naval treaty) straight away taken our of service and used as a training ship.(to heavy, to high cal weapons i think).
When tention brewed up with China, they just made new Battleships in the Kongo line.
Which at that stage is then just full Battleship building. not upgrading or modernizing.
i also believe that the technical term for a BC that gets a upgrade with bigger guns, better AA, but is missing the Armor, Waterline etc. is known as a Pocket Battleship.
Due to it having much less displacement in the water. higher speed but lower armor values then a full blown Battleship.

Which again brings us full circle...
WW1 ships, would be upgraded and retro fitted mostly before the war.
During the war it was more common that passenger and cargo ships would be converted.
Although some ships did under go retro fitting.
But a full upgrade, as we see in the game BB1 -> BB2 -> BB 3 is not done.
As it would require for the whole ship to be taken appart and rebuild acording to the new design.

if we look for instance at the USA BB line(1 and 2). we see that they have the New York and North Carolina class Battleships(1 and 2 respective) unlocked
now the New York class was a upgrade of the Wayoming, the Wayoming itself was a "dreadnought battleship" of the USN. and designed prior to 1908, and 2 where build between 1908 and 1914(carried the names: USS New York and USS Texas)
The New York how ever was fully designed as a Battleship.
It was, Faster, Had bigger Guns, bigger Rudders, Thicker Armor, Better Deck and Turret armor, it was bigger and displaced more tons.
It still ran on steam driven boilers. which underwent some modernization to oil boilers in 25-26(took a whole year to replace 14coal boilers, and reduce the propshafts from 4 to 2).
Gun load out(AA and small back up/close range guns) changed and was done with relative easy(mannor of months). but they never touched the main cannons of the ship. and she remained with 10x 14"/45 caliber Cannons in a 5x2 setup untill she was decomisioned.

the North Carolina class Battleship, was a major upgrade over the New York Class.
a fast reduction of boilers because they became steam-electric. more propshafts, she was much faster(7 to 8 knots faster) then the New York Class, and had a bigger range, much heavier(10.000tons more, 18.000 tons loaded), and carried 9x16"/45Caliber Cannons. in a 3x3 loadout. All of her armor(excluding the Armor belt) got increased by at least 4inches.(decks where spaced and layered into 3).
Unlike the New York class, she was never retro fitted in her armnement. and she remained as she was as she was launched.

now when we look at those changes. (its a game, so imagine it).
We have a fleet of New York Class ships, we then unlock the North Carolina class, and our New York ships need to be upgraded...
FIrst of all, they need to be taken appart, made longer, made wider, increase the armor by 4inch on them, Increase the prop shafts from 2 to 4, reduce and improve the armor of the boiler room to fit in 8boilers(rather then 14), but these are electrical steam. so we need to re-wire the entire ship as well. then we get the 3th layer of deck, followed by spacing, a 2nd layer of deck, followed by spacing, then the main deck and armor it. in our new deck design we need to have it adapted to go from 5 to 3 Gun mantles. and re-inforce the 2 out of order Gun mantles with something else(ammo store, fual, provisions etc) the entire ship need to undergo a Frame(bone) strenght program, to deal with the stress and impact of 9x16"/45Cal. cannons shooting over prolonged time. then the super-structure needs to be upgraded, and the deck below(should be already in the design) strenghtend to support that weight, and displace it over the whole of the ship, so it does not becomes top heavy(to much). (keep in mind here, to increase the boiler room by 2 and the propshafts from 4 to 2 on the New York alone took already a year).
OR
We just create a new battleship, and start with a new design and build it right from the start as intented.

Which would be easier/faster to do if you are at war. to maximize your production, and keep your fleets active as well.

i really believe that Paradox made the right call on this.
(again, if i am wrong please show me, i love to learn more(always).
as i don't know of any ship that underwent such heavy modernization and upgrading to go from a WW1 era to the WW2 era, During or Before the war.

EDIT:
The USS Nevada(BB-36) is one i know off, that underwent some heavy modernization after she took 2 torpedo hits and beached herself on the banks during the Pearl Harbor attacks in 12.41.
She was recovered, underwent modernization. and refloated in feb.42(3months after recovery).
But in all fairness all this modernization did, was change boilers(they got faster with it. from 12oil-fired boilers to 6steam turbines. and got a upgrade in the super structure.
The layout of Number of Guns, and how/where they where placed remained the same(2x3 + 2x2 14"/45Cal.)

so again not the type of upgrade from ship to ship, as the topic is about.

[slatingsangan]

the doctrines 'upgrades' the ships

[Tea²Time]

I did HOURS of research on what to best upgrade with each each tank, ship and plane variant. Here are my findings:

Tank: https://www.youtube.com/watch?v=iOb9c5B4Ab4
Ship: https://www.youtube.com/watch?v=IY77PNgaf3w
Plane: https://www.youtube.com/watch?v=J1Vu8APfBHQ

[[NL]Ibahalii]

Always eager to learn(even from a topic 1,5years old at this stage).
I did what you told me...
Had to read the topic again to see what this was on about again.
and sure enough..

Yes Wingnut retro/refitting can be done extensively nobody is debating that.
What the debate was on about was, is it do-able in a war....
And as said i googled the Queen Elizabeth Class battleships.
and it did not take me long to conclude that what i said 1,5years ago still holds up today.

Which is.
In times of peace;
Old war ships can be retro/refitted into entire new models to save money for building a new ship.
(or because the ship is just of historical value, the country is really attached to them etc).
This could litteraly mean, that they would take the ship appert to the last rivit, and rebuild it into the new model, including guns, super-structure, decks, compartments and so forth.
During a war;
It almost NEVER happened (the Japanese Kongo class BC to BB during the war is a exception to that rule).
The retro/refitting most ships then recieved where much more in line with, changing a power plant, adding/removing AA-guns, adding/upgrading radar, depth charges, torpedo's, the few rare cases where a crane and hanger would be mounted ontop a BB to give them air capabilites and such.
But never on the Main-guns, Hull, Decks, Super-structure, Frame and bone strenght, Propshafts, Rudders or any other major component of a ship that would allow to go from a(in game terms) Tier 1 to a Tier 2 ship.

What you told me to google, even concludes that very quickly in it's upgrade/time scedual from moment between the wars:

Between the wars, the ships received considerable upgrades, including new machinery, small-tube boilers, deck armour upgrades, torpedo belt armour, trunked funnels, new secondary armament and anti-aircraft armament, and many improvements in gunlaying and electronics. Queen Elizabeth, Valiant, and Warspite were the most modernised, with all three receiving the new "Queen Anne's mansion" block superstructure for the bridge, whilst twenty 4.5" dual-purpose guns in 10 turret mountings replaced the 6" casemate secondary weapons on Queen Elizabeth and Valiant. Warspite kept her 6" secondary guns, now reduced to just four per battery.

And how despite all the extencive upgrading/rebuilding etc translated into a war capable ship:

By the Second World War, the class were showing their age.

Barham and Malaya, the least-modernized of the class, were at a disadvantage compared to modern battleships. In spite of this, Malaya prevented an attack on a transatlantic convoy by the modern German battlecruisers Scharnhorst and Gneisenau by her presence.[15] Queen Elizabeth, Warspite, and Valiant, the more modernised of the class, fared better. With her modern fire control equipment, Warspite scored a hit on an Italian battleship during the Battle of Calabria at a range of more than 26,000 yards, one of the longest range naval artillery hits in history.[16]

Modern torpedoes outclassed their torpedo belt protection: in November 1941, Barham, the least modernised of the quintet, was torpedoed by a U-boat and sank in five minutes, with the loss of over 800 of her crew, when her magazines detonated. Warspite survived a direct hit and two near-misses[17] by German glider bombs, while Queen Elizabeth and Valiant were repaired and returned to service after being badly damaged by limpet mines[18] placed by Italian frogmen during a raid at Alexandria Harbour in 1941.

Despite all the retro-fitting, despite all the upgrading, the changing of guns, powerplants, propshafts, armor, deck load-out, despite everything.
The moment WW2 broke out those ships where still obsolete.

Re-aferming what i said 1,5years ago.

now when we look at those changes. (its a game, so imagine it).
We have a fleet of New York Class ships, we then unlock the North Carolina class, and our New York ships need to be upgraded...
FIrst of all, they need to be taken appart, made longer, made wider, increase the armor by 4inch on them, Increase the prop shafts from 2 to 4, reduce and improve the armor of the boiler room to fit in 8boilers(rather then 14), but these are electrical steam. so we need to re-wire the entire ship as well. then we get the 3th layer of deck, followed by spacing, a 2nd layer of deck, followed by spacing, then the main deck and armor it. in our new deck design we need to have it adapted to go from 5 to 3 Gun mantles. and re-inforce the 2 out of order Gun mantles with something else(ammo store, fual, provisions etc) the entire ship need to undergo a Frame(bone) strenght program, to deal with the stress and impact of 9x16"/45Cal. cannons shooting over prolonged time. then the super-structure needs to be upgraded, and the deck below(should be already in the design) strenghtend to support that weight, and displace it over the whole of the ship, so it does not becomes top heavy(to much). (keep in mind here, to increase the boiler room by 2 and the propshafts from 4 to 2 on the New York alone took already a year).
OR
We just create a new battleship, and start with a new design and build it right from the start as intented.

[[NL]Ibahalii]

I agree that the game has limitations...

But the main haul conversions. to be really in-line of making a Tier 1 into Tier2, or a Tier 2 into a Tier 3. you could never complete within the time frame of the game.
The shortest time for a ship of the line(capital ship) of any of the major nations in pre-war time, had their retrofitting done pre-1936(like the HMS Repulse(several refits from 1925~1933), the CV HMS Malaya(1936 completed), Giuseppe Garibaldi(Italian light cruiser(launched 1936, completed 1938, refit 1957-1961). and these are just a few of 3ship classes.
when you look at the time frame of the Italian light cruiser..thats already 4years to refit it, sure it had a refit long overdue.
now lets look at the Repulse in specific how the upgrade/retrofitting went and what was done.
The Repulse started refitting in the 1924's(1923 if you count from when it was planned),

They returned home ten months later in September 1924.[11] Shortly after her return the ship's pair of 3-inch AA guns and her two single four-inch gun mounts were removed and replaced with four QF four-inch Mark V AA guns.[18] The Battlecruiser Squadron visited Lisbon in February 1925 to participate in the Vasco da Gama celebrations before continuing on the Mediterranean for exercises.[19] A squash court was added on the starboard side between the funnels for the Prince of Wales' tour of Africa and South America[18] that lasted from March to October.[20] Upon her return she was refitted from November 1925 to July 1926 and had a high-angle control position (HACP) added to her fore-top.

so then we are in 1926 already(+2years)

After Repulse completed her 1926 refit she remained in commission, aside from a brief refit in July–September 1927, with the Battlecruiser Squadron of the Atlantic Fleet until she was paid off in June 1932.

then we are in 1927(+1year)
She sees service up to 1933:

prior to beginning her reconstruction in April 1933. Most of the existing layers of high-tensile steel that constituted the ship's horizontal armour were replaced by non-cemented armour plates 2.5–3.5 inches (64–89 mm) in thickness and the torpedo control tower was removed from the aft superstructure.[21] A fixed catapult replaced the midships 4-inch triple mount and a hangar was built on each side of the rear funnel to house two of the ship's Fairey III aircraft. One additional aircraft could be carried on the deck and another on the catapult itself.[22]

Electric cranes were mounted above each hangar to handle the aircraft. The four 4-inch AA guns were moved, one pair abreast the rear funnel at the level of the hangar roof and the other pair abreast the fore funnel on the forecastle deck. Four prototype QF 4-inch Mark XV dual-purpose guns were added in twin-gun Mark XVIII mounts abreast the mainmast. Two octuple Mark VI 2-pounder mounts were fitted on extensions of the conning-tower platform abreast the fore funnel. Above these a pair of quadruple Mark II* mountings for the 0.5-inch Vickers Mark III machine gun were added.[22] These mounts could depress to −10° and elevate to a maximum of 70°. The machine guns fired a 1.326-ounce (37.6 g) bullet at a muzzle velocity of 2,520 ft/s (770 m/s). This gave the gun a maximum range of about 5,000 yd (4,600 m), although its effective range was only 800 yd (730 m)[23] Repulse received two High-Angle Control System anti-aircraft directors, one Mark II on the fore-top and a Mark I* mounted on a pedestal above the rear superstructure. The two submerged torpedo tubes were removed and the vacant spaces sub-divided and turned into store-rooms.[24] Repulse was assigned to the Mediterranean Fleet when she recommissioned in April 1936.

And then we are in 1936(+3years) where she sees service in the Spannish Civil war.

She transported 500 refugees from Valencia and Palma, Majorca to Marseilles, France in late 1936 after the start of the Spanish Civil War. The ship was present at the Coronation Fleet Review at Spithead on 20 May 1937 for George VI. Repulse was sent to Haifa in July 1938 to maintain order during the Arab Revolt.

Then in 1938 She undergoes one more refitting:

She was selected to convey the King and Queen during their May 1939 Canadian Tour and she was refitted between October 1938 and March 1939 for this role. The twin 4-inch AA guns were replaced by two more Mark V guns and two additional quadruple .50-calibre mounts were added. The King and Queen ultimately travelled aboard the liner RMS Empress of Australia while Repulse escorting them on the first half of the journey.

Bringing us into 1939(+1year)
All in all, she needed 4years of interupted time and planning broken up by active service to be refitted into something slightly more usefull in the war, then what she was when she was launched in 1916.
And now i'm being very generous with the numbers, since i am not including the upgrades she recieved from 1918~1921.(Interwar period). if you take those with it thats another +3years. bringing the total up to 7years.

Repulse began a major refit at Portsmouth on 17 December 1918[11] intended to drastically improve her armour protection. Her existing 6-inch armour belt was replaced by 9-inch (229 mm) armour plates made surplus by the conversion of the battleship Almirante Cochrane (originally ordered by Chile and purchased after the war began) to the aircraft carrier HMS Eagle. The old armour was fitted between the main and upper decks, above the new armour belt. Additional high-tensile plating was added to the decks over the magazines. The ship's anti-torpedo bulge was deepened and reworked along the lines of that installed on the battleship HMS Ramillies. The bulge covered her hull from the submerged torpedo room to 'Y' magazine and the inner compartments of which were filled with crushing tubes. The bulges added 12 feet 8 inches (3.9 m) to her beam and 1 foot 4 inches (0.4 m) to her draught. The refit added about 4,500 long tons (4,600 t) to her displacement and raised her metacentric height to 6.4 feet (2.0 m) at deep load. Three 30-foot (9.1 m) rangefinders were also added as well as eight torpedo tubes in twin mounts on the upper deck. Both flying-off platforms were removed.[17] This refit cost £860,684.

Repulse was recommissioned on 1 January 1921

So if we take the 1930 rebuild program we need 4years of time.
And if we take the whole upgrade cycle since she was launched then we need 7years time.

This was the amount of time needed to upgrade a first world war ship into a somewhat world world 2 ready ship, and this is not even swapping between tiers,
As the repulse was orginally designed as a battleship. but due to the war sized down to a battle cruiser:

HMS Repulse was a Renown-class battlecruiser of the Royal Navy built during the First World War. Originally laid down as an improved version of the Revenge-class battleships, her construction was suspended on the outbreak of war because she would not be ready in a timely manner. Admiral Lord Fisher, upon becoming First Sea Lord, gained approval to restart her construction as a battlecruiser that could be built and enter service quickly. The Director of Naval Construction (DNC), Eustace Tennyson-D'Eyncourt, quickly produced an entirely new design to meet Admiral Lord Fisher's requirements and the builders agreed to deliver the ships in 15 months.

Regardless of this.
It would take 4 years for (inlight of the 1918~1921 refit) minor upgrades done to her. sure they where interupted times, and if they did it in one go, they might have been able to do in..idk...2,..3 years?...
that still puts you on 1938/1939. which is cutting it very close. for a fleet (which you kinda have to asume) Paradox made with what ready in 1936(After all the repulse's refits, cept for the AA battery).

Now this is just 1 ship....From BC to slightly more modern BC. and though they overhauled a lot. it never came on par with the HMS King George V for instance(Which was retro fitted as it was build in 1937, and came as a "new" era battleship into the fleet at "41).

And so far all the upgrade sceduals of schips that i have seen. look the same...
Anything bigger then a LC(Light Cruiser) would take at least 4years of spreaded upgrading. and retro fitting.

you can look on the other side of the big blue pont and see Japan doing its Stuff on the Kongo class. 1911 build - 1924 first refit, lasted till 1933 and she reclasified as a BB(A BC -> BB upgrade), then from 34 to 36 there is a period of interupted upgrades on her. and she becomes the flagship of the IJN. untill the Yamashiro BB took the flag back. (35~36) and Kongo is placed as a reserve ship, straight away launching a new refit program on her in 35, lasting till 37. then seeing action till 41. where she gets yet another upgrade pack that lasts(in broken up sections) till the end of 43, in 44 she will see her final 2 campaigns and be sunk on 21-nov-44(USA date), 20-jan-45(IJN date).
Now the kongo is a story differently as we are talking from BC to BB upgrade, but as you can see. that was a project that never ended basicly. and she could never meet up with the demand of her new "title" of Battleship, as the Yamato and Fusō-class BB's where better in any aspect besides speed.

This patern you will see over all the nations. that even when not in war, upgrading a ship costed vast sums of money(that many countries where not willing to spend), time, labour and materials(that where also hard needed for the airforce and armies).

So i really don't see why Paradox should have given us the option to upgrade a ship.
With the XP we earn we can already design better versions of the same class of ships.
You just need to build the new type for the change to come into effect, with DD/LC's etc not to big of a problem. but to replace a BC/BB/CV IS a problem.
But this is where you hit the limitation of the game upgrade system.

Armies don't really upgrade their old models either...
They just replace them. If you design a stronger tank. you need to produce those first, or have some already in stock to convert them into the new type. (Like a Tiger with a +5 gun).

And that is a option that is not in game for ships.
Besides all that, even in the Airforce/Armor department you can upgrade Tier 1 model A into Tier 1 model B, But not Tier 1 Model A into Tier 2 Model A.

And that is a limitation of the game that is just there.
Untill Paradox or a skilled modder, can make the code, that we (for instance) Apply the XP we gain directly to a already deployed ship.
(Using UK as example).
Say you have a fleet with 3 King George V BB's. and you got 150XP for naval.
That you can then select your first BB. and add some XP onto it...increasing it's AA or powerplant, Radar, limited higher caliber weapons etc).
Where after the upgrade the ship needs to go into a port to upgrade for "x" amount of days. and that "x" of days would then be desided by port size and how much naval factory output you have.
(Example)
You upgrade the AA + 2 and +1 on the powerplant.
Each upgrade point would cost you 1000 naval production(sounds a lot, its not).
Say you have 30 naval yards, and are docked in a harbor with level 5. then you would get:

Days Upgrade = (NY*NP) / DL

Or more explained:

Days Upgrade = (30*20)/5

Result:

 120 days upgrade = 600/5

in that way you could "upgrade" your ships in line with how it should be.
Unfortunally to my knowhow, there is no plan for Paradox to make this, nor do i know of any mod that adds this to the game.

But in my honest opion, a system that uses that sort of math to calculate where ships need to be in port. would be the only fair way to do such a thing.

Alternativly(more beating around the bush)
You could break the ships down in parts.
Where you use your naval(and land industry) to create ship compants.
Like a lot of the AA guns on any type of ship was of the same make, same caliber etc. just some ships had 4x AA(DD's). others had 62x AA(BB's). as some of the AA units in the land amries. (the Bofor's Quad is a good example of that).
you can do the same with small and large caliber guns for ships.
Creating up to 10" cannons for classes up to HC(Heavy Cruisers) and,
Creating up to 18" cannons for classes up to SHBB.(Cannons of the SHBB Yamato).
Then using your naval yard to lay the keel of a ship type of your desire. where you add the compents to it. and your naval yard will the asamble your ship.
That way your ship contains multible parts, and the game should(in theory, with some extra code writen) allow to upgrade the parts of your ship.
By updating the model type of said part. and producing them. the game should then treat the ship as it treats the army/airforce and upgrade individual parts of the ship.

But it any otherway i would find highly unrealistic or even doable to meet up with the enormous amount of time and effort it would cost to upgrade those ships.
*Edit: The cost(money) of the HMS Repulse 1918~1921 refit alone would be the value of todays: £57,308,008.31 just give a clearer picture of it :).

[RoastCoffee]

I don't think you should be able to replace an older ship with a later design. However, I do think you ought to be able to modify the ships existing design, as was done with some pre-war carriers (i.e., lenghening flight decks, removing surface gunnery, but keeping same hull, of course). And I think that ship just goes out of action for six months during the major refit. Less time for minor refits, like upping AA batteries.