Shipbucket

I've been writing an alternate history work in Korean for some time now, with the following background:

I'll be posting various ships I've designed for the Greater Korean Empire.


Keumgang-Class Battlecruiser



Battlecruiser designed by Vickers, as a modernized version of Kongo and Tiger. It is the first capital ship of Daihan, and the grunt horse of the future Korean Imperial Navy, being modernized heavily to keep up with later battleships.



"Jungsun" Heavy Cruiser (WIP)



Displacement: 10,497 tons standard / 12,815 tons full load
Length: 197.9 m
Beam: 20.0m
Draught: 6.8 m
Propulsion: 110,000 shp on four shafts
Speed: 33 kt
Range: 7,800 nmi at 14 knots
Complement: 652
Armament:
- 9 x 20 cm/50 naval guns (3x3)
- 8 x 10 cm/65 dual purpose guns (4x2)
- 20 x QF 2-pounder Mark VIII (5x4)
Armor:
- Belt: 150 mm
- Barbettes: 160 mm
- Turret: 200 mm
- Deck: 65 mm
- Conning Tower: 150 mm
Aircraft carried: 3

The Washington Naval Treaty of 1922 imposed, among other things, the definition of a capital ship as a warship of more than 10,000 tons standard displacement or with armament of a calibre greater than eight inches (203 mm). There was the concern that a subsequent race in building larger, more powerful cruisers might subvert the usefulness of the prohibition on capital ship construction and encourage navies to squander their now-limited perimissible tonnage for capital ships on fast vessels designed specifically to hunt down large cruisers. To avert these challenges, representatives of the Eight Powers set limits on the tonnage and firepower of cruisers to 10,000 tons in displacement and 8 inches (200 mm) for maximum main gun caliber. In 1930 the Washington Naval Treaty was extended by the London Naval Treaty, which finally settled the arguments on cruisers which had raged in the 1920s. The treaty defined limits on both heavy cruisers - those with guns larger than 155 mm (6.1 inches) - and light cruisers - those with smaller-calibre guns. The limit of 10,000 tons displacement still applied to both. This was the point at which the split between 'heavy' and 'light' cruisers finally became official and widespread.

While the Great Powers all worked to try and develop new, powerful cruiser classes, Daihan enjoyed a self-imposed holiday on cruiser construction and focused on the buildup of its capital ships and destroyers. It had just started finishing up a massive expansion of naval dockyards all around the country, and as such there was no real room to spare in designing and building cruisers. Instead, during the 1920s it took on orders from Japan (which was considered the same country under the special catergory of the WNT), thus gathering gathering in both ship construction and designing.

By the time the London Naval Treaty came around, Daihan had merged with others to form the Greater Korean Empire. With a decade worth of knowledge and expertise, a large militarized labor force, and the world in economic crisis since the Lombard Street Crash of 1928, Korea set out to spend ahead of depression. Part of this was to order twenty heavy cruisers. This went against the world trend, since it was thought that in a likely cruiser engagement, a larger number of 6-inch guns would be preferable to a smaller number of 8-inch, due to the belief that the heavier shell of the 8-inch weapon was of little advantage, as most ships that could withstand a 6-inch hit were also well-protected against 8-inch shells. So far only Japan was willing to continue with heavy cruisers, using the planned upgunning of the Mogami-class in case of conflict with China. There was also the United States, but budgetary concerns kept the USN back from making any major commitments beyond experimental vessels.

However, Korea had two hidden cards: use of tungsten steel in AP shell construction, and a high velocity 10 cm dual purpose gun. This first method resulted ultraheavy shells, of which the 8-inch variety would weigh over 400 kg. was This equivalent to that of a regular 12-inch shell, and thus sufficient enough to punch through all ships short of a battleship. The disadvantages were the necessity of stronger handling gears, fewer rounds at fixed displacement, and increased wear on the barrels. However, Korea believed the increased impact for armor-piercing and the high rate of fire in bombardments were enough to offset these advantages. As for the high velocity 10 cm dual purpose gun, it is a modified version of the QF 4.5-inch naval gun, which Korea had joint-developed the basics, but went towards smaller caliber and higher velocity. While the high velocity and flat trajectory meant that punching through massed destroyers would be easier, there was a high rate of wear on the barrels themselves. Armed with these double-edged weapons, the Korean Imperial navy set out to design its first heavy cruiser.



Heuksu-Class Main Force Cruiser



Displacement: 24,980 tons standard / 30,670 tons full load
Length: 240.8 m
Beam: 28.0 m
Draught: 8.00 m
Propulsion: 110,000 shp on four shafts
Speed: 31.5 kt
Range: 7,500 nmi at 14 knots
Complement: 1,350
Armament:
- 3 x 25 cm/50 naval guns (3x3)
- 12 x 12.5 cm/45 dual purpose guns (6x2)
- 16 × 4 cm/70 AA guns (4x4)
Armor:
- Belt: 330 mm
- Barbettes: 350 mm
- Turret: 325 mm
- Deck: 160 mm
- Conning Tower: 250 mm
Aircraft carried: 2

During the early 1930s, Britain set about pushing for a limit of 25,000 tons and 12" main armament for capital ships. While Korea thought this absurd in the face of a belligerent China, it did humor its close ally by supporting the notion and designing its own 25,000 capital ship. The result was the Heuksu.

Named for the longest river of the Empire (internationally known as Amur), Heuksu attempted to push the possibilities of 25,00 tons displacement to the limit. The goal was immunity from 14" shells between 19,000 and 30,000 yards while also achieving a maximum speed of over 30 knots. If this meant that the main armament needed to be made smaller, that was a sacrifice Korea was willing to make. It did have a large stockpile of tungsten from its mines, so if there need be it would be manufacturing heavy AP rounds to boost the smaller caliber. Ultimately the result barely made it.

The Chinese denunciation of naval treaties in 1934 after demanding naval parity virtually destroyed Britain's ambitions. With the second most powerful industrial power unchained, reducing tonnage limits was not going to be accepted by either Korea or Japan. Along with the 25,000 ton plan, Heuksu was almost thrown away as it was considered just an exercise in designing. It seemed that Heuksu would be a still born.

However, the eruption of the Sino-Korean War in 1936 revived the design. With the Chinese armada blockading all of Northeast Asia, a fast sturdy vessel was needed to crack through the Bamboo Curtain. Heuksu and her sisters were ordered immediately, and when they entered action in 1938, they managed to punch through parts of the blockage force. The birth of the "Main Force Cruiser" started a revolution, as the death of naval restrictions led to escalating growth of cruisers into the realm of capital ships.



Gwangmu Battleship (WIP)



Displacement: 45,720 tons standard / 56,820 tons full load
Length: 243.1 m
Beam: 36.0 m
Draught: 10.1 m
Propulsion: 130,000 shp on four shafts
Speed: 27.8 kt
Range: 7,200 nmi at 16 knots
Complement: 2,120
Armament:
- 10 x 40 cm/45 naval guns (2x3, 2x2)
- 20 x 12.5 cm/45 dual purpose guns (10x2)
- 64 × 4 cm/56 AA guns (14x4)
Armor:
- Belt: 400 mm
- Barbettes: 530 mm
- Turret: 510 mm
- Deck: 150 mm
- Conning Tower: 530 mm
Aircraft carried: 2

Battleship designed after the start of the Sino-Korean War in 1936. It was the first battleship to be finished under the escalator clause allowing displacement of 45,000 tons. Armored heavily to protect against possible 18" rounds, it went the opposite direction of the American design philosophy of speed over armor.

Currently looking over the heavy cruiser before going on to finish Gwangmu. Any thoughts on Jungsun? If you need any specifcations, I'll add them in. Current thoughts are merging the smokestacks and using the freed up space for additional lifeboats.

I like the look a nice blend of RN/IJN stuff, not sure I would bother with the tungsten would it really be doable with 1930s tech ?
Will this not do something quite large to the treaty limits (not that a IJN without an empire will be able to afford the ships to require the treaty's in the first place IMO ?)
My understanding was that 8' CAs beat 6' CLs (most CA/CLs are not protected v 8' hits, but are v 6'), but that 6'CLs beat DDs better than 8' CAs (more gun/faster ROF = more hits and DDs have no protection) and Killing DDs (With TT) therefore protecting BBs was more important as BBs beat CAs ?

JSB

I would note that at present the only name on the credits line is yours, you will need to credit Hood and whoever drew the original hull you have used for the Jungsun.

On the drawing you would not normally have the aft superstructure higher than your forward superstructure. 8" guns are fine, and at the time you are building the ships, 1929-35 (they would not build all 20 at once but would be like the British County class and would be spread over several years) the 8" gun was the weapon of choice for the major seapowers.

Those two are the major allies of Korea, so the influence is bound to seep in. It's only with Gwangmu that a "pure" Korean design comes about.

Japan was actually already making such rounds for tank guns in our history. With the greater access to tungsten and the technology to mass refine it, Korea is doing things on a larger scale.

There isn't any heavy cruiser limit in this world's LNT, because no one but the UK wanted it.

My understanding was that by 1930 most CA designs had enough armor to provide limited protection against 8" hits, thus the push towards 6" for volume of fire. Korea's logic (whether it is right or wrong) is that CAs should have enough force to punch through any possible ship short of a battleship/battlecruiser, and still have enough volume to take out DDs (thus the 10 cm DPs). Originally I was thinking of a total of sixteen 10 cms, but realized that would be overkill even if inspired by Keumgang and that would not leave enough free tonnage for the aircraft and such.

I keep forgetting that, done.

Ah, moved the aft director and thus lowered the height.

Of course, it's 20 orders, not 20 constructions

Full Resolution

This should be finished, unless someone has comments on something. What do you think?

What's its displacement ? is it supposed to be under 10,000t (or even lower ?) I would guess it would be slightly over due to the triple turrets (and the width needed for the twin 100mm on both sides). Also how many 40mm is reasonable for 1935 (IMO not more than 2 oct mounts ?).

Have you done a springsharp or anything ? my guess would be 13000t depending on the belt thickness ?

I like it but it looks more post treaty to me, with WW2 AA fit.

JSB

I added the specifications including displacement to the original post. It's already over 10,000 tons but the fiction of it being within treaty limits was maintained by not actually filling it up to standard.

Kent-class had 8 Pom-poms in quad mounts and 8 0.5-inch Mk.III machine guns in quad mounts, while Norfolk-class had 16 Pom-poms in oct mounts. Korea decided to just unify all AA guns to the Pom-pom and dispersed them around, resulting in the 20 Pom-poms in quad mounts.

Some very interesting designs here. An AU thread to watch methinks.

_________________
Hood's Worklist
English Electric Canberra FD
Interwar RN Capital Ships
Super-Darings
Never-Were British Aircraft

I've seen your stuffs at Korean cummunity.(wasn't it Bulgeun Oyatggot?)
Good to see your AU again