Shipbucket

I think the US put the turret, conning tower, and other above-deck armor as "protection". You'll notice that the April design is around 2,200 tons heavier, likely due to the thicker turret armor and such.

Hope we are not derailing the thread to much, but I do find it fascinating comparing the 2 designs.

The really interesting part for me is that you can make a ship with much bigger guns (9x18' rather than 12x16' and more 5/38s), less power (130 v 170Kshp) and much thicker belt (14.75' v 11') and still have it (.5Kn) faster and only a bit more standard displacement (495t)

IMO it does show the effectiveness of cutting down the number of turrets and making a short belt in a large well shaped hull. (and the effectiveness of good lawyers in a treaty environment)

JSB

If you would keep it to discussing 25,000 or so ton ships it would be better.

But information on the use of Springsharp is handy to everybody. So I do not have a problem with it.

We are here to learn, to hone our skills, to make the drawings better, anything that helps that has everybodys approval.

Don't worry, currently ironing out the bugs with my 25,000 ton design.

Another go at a RN ship (this time not on the cheap, but just treaty legal) Will have a go making her later.

GB 25kt JUST, GB BC laid down 1932

Displacement:
23,735 t light; 24,991 t standard; 26,580 t normal; 27,851 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(696.17 ft / 690.00 ft) x 90.00 ft (Bulges 100.00 ft) x (34.00 / 35.12 ft)
(212.19 m / 210.31 m) x 27.43 m (Bulges 30.48 m) x (10.36 / 10.71 m)

Armament:
8 - 12.00" / 305 mm 50.0 cal guns - 914.65lbs / 414.88kg shells, 150 per gun
Breech loading guns in turret on barbette mounts, 1932 Model
2 x Quad mounts on centreline, evenly spread
8 - 4.00" / 102 mm 45.0 cal guns - 32.28lbs / 14.64kg shells, 800 per gun
Anti-air guns in deck mounts, 1932 Model
8 x Single mounts on sides, aft evenly spread
8 raised mounts
Weight of broadside 7,575 lbs / 3,436 kg

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 12.0" / 305 mm 310.00 ft / 94.49 m 23.00 ft / 7.01 m
Ends: Unarmoured
Main Belt covers 69 % of normal length
Main Belt inclined -5.00 degrees (positive = in)

- Torpedo Bulkhead - Strengthened structural bulkheads:
3.00" / 76 mm 500.00 ft / 152.40 m 36.00 ft / 10.97 m
Beam between torpedo bulkheads 82.00 ft / 24.99 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 16.0" / 406 mm 7.00" / 178 mm 16.0" / 406 mm
2nd: 1.00" / 25 mm - -

- Armoured deck - single deck:
For and Aft decks: 6.00" / 152 mm
Forecastle: 0.00" / 0 mm Quarter deck: 4.00" / 102 mm

- Conning towers: Forward 3.00" / 76 mm, Aft 3.00" / 76 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 94,875 shp / 70,777 Kw = 30.00 kts
Range 6,000nm at 15.00 kts
Bunker at max displacement = 2,860 tons

Complement:
1,040 - 1,353

Cost:
£9.064 million / $36.258 million

Distribution of weights at normal displacement:
Armament: 1,493 tons, 5.6 %
- Guns: 1,493 tons, 5.6 %
Armour: 11,440 tons, 43.0 %
- Belts: 3,906 tons, 14.7 %
- Torpedo bulkhead: 1,998 tons, 7.5 %
- Armament: 1,534 tons, 5.8 %
- Armour Deck: 3,887 tons, 14.6 %
- Conning Towers: 115 tons, 0.4 %
Machinery: 2,800 tons, 10.5 %
Hull, fittings & equipment: 7,952 tons, 29.9 %
Fuel, ammunition & stores: 2,845 tons, 10.7 %
Miscellaneous weights: 50 tons, 0.2 %
- Above deck: 50 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
46,235 lbs / 20,972 Kg = 53.5 x 12.0 " / 305 mm shells or 9.3 torpedoes
Stability (Unstable if below 1.00): 1.27
Metacentric height 6.5 ft / 2.0 m
Roll period: 16.4 seconds
Steadiness - As gun platform (Average = 50 %): 75 %
- Recoil effect (Restricted arc if above 1.00): 0.33
Seaboat quality (Average = 1.00): 1.50

Hull form characteristics:
Hull has a flush deck,
a normal bow and large transom stern
Block coefficient (normal/deep): 0.397 / 0.402
Length to Beam Ratio: 6.90 : 1
'Natural speed' for length: 31.46 kts
Power going to wave formation at top speed: 51 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 10.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20.00 %, 35.00 ft / 10.67 m, 28.00 ft / 8.53 m
- Forward deck: 30.00 %, 28.00 ft / 8.53 m, 21.00 ft / 6.40 m
- Aft deck: 35.00 %, 21.00 ft / 6.40 m, 18.00 ft / 5.49 m
- Quarter deck: 15.00 %, 18.00 ft / 5.49 m, 18.00 ft / 5.49 m
- Average freeboard: 23.04 ft / 7.02 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 68.2 %
- Above water (accommodation/working, high = better): 158.1 %
Waterplane Area: 39,583 Square feet or 3,677 Square metres
Displacement factor (Displacement / loading): 109 %
Structure weight / hull surface area: 170 lbs/sq ft or 830 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.92
- Longitudinal: 2.04
- Overall: 1.00
Excellent machinery, storage, compartmentation space
Excellent accommodation and workspace room
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily


- Might drop the speed a bit (do I need more than 28 ?)
- would swap out the 4' for 4' twins post treaty
- fit 0.5' quads then later 40mm

JSB

Here's a maverick design, supposing that the Greater Korean Empire designed in case the 1936 London Naval Conference resulted in a 25,000 ton limitation, and eventually built when the Sino-Korean War started in 1936:

Heuksu, KJH Battlecruiser laid down 1936

Displacement:
24,128 t light; 24,974 t standard; 26,557 t normal; 27,823 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(790.03 ft / 771.00 ft) x 91.86 ft x (26.25 / 27.15 ft)
(240.80 m / 235.00 m) x 28.00 m x (8.00 / 8.28 m)

Armament:
9 - 9.84" / 250 mm 50.0 cal guns - 504.70lbs / 228.93kg shells, 100 per gun
Breech loading guns in turret on barbette mounts, 1936 Model
3 x Triple mounts on centreline ends, majority forward
1 raised mount - superfiring
12 - 4.92" / 125 mm 45.0 cal guns - 60.10lbs / 27.26kg shells, 150 per gun
Breech loading guns in deck and hoist mounts, 1936 Model
6 x 2-gun mounts on sides, evenly spread
16 - 1.57" / 40.0 mm 70.0 cal guns - 2.19lbs / 0.99kg shells, 150 per gun
Anti-air guns in deck mounts, 1936 Model
4 x Quad mounts on centreline, evenly spread
Weight of broadside 5,299 lbs / 2,403 kg

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 13.0" / 330 mm 431.76 ft / 131.60 m 11.52 ft / 3.51 m
Ends: Unarmoured
Main Belt covers 86 % of normal length

- Torpedo Bulkhead:
1.50" / 38 mm 431.76 ft / 131.60 m 23.10 ft / 7.04 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 12.8" / 325 mm 7.87" / 200 mm 13.8" / 350 mm
2nd: 0.98" / 25 mm 0.98" / 25 mm -

- Armoured deck - multiple decks: 6.30" / 160 mm For and Aft decks

- Conning towers: Forward 9.84" / 250 mm, Aft 0.00" / 0 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 116,806 shp / 87,137 Kw = 31.50 kts
Range 7,500nm at 14.00 kts
Bunker at max displacement = 2,848 tons

Complement:
1,039 - 1,352

Cost:
£9.741 million / $38.964 million

Distribution of weights at normal displacement:
Armament: 1,327 tons, 5.0 %
Armour: 9,622 tons, 36.2 %
- Belts: 2,785 tons, 10.5 %
- Torpedo bulkhead: 552 tons, 2.1 %
- Armament: 1,850 tons, 7.0 %
- Armour Deck: 4,245 tons, 16.0 %
- Conning Tower: 189 tons, 0.7 %
Machinery: 3,277 tons, 12.3 %
Hull, fittings & equipment: 9,901 tons, 37.3 %
Fuel, ammunition & stores: 2,429 tons, 9.1 %
Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
50,203 lbs / 22,772 Kg = 105.3 x 9.8 " / 250 mm shells or 8.1 torpedoes
Stability (Unstable if below 1.00): 1.06
Metacentric height 4.9 ft / 1.5 m
Roll period: 17.4 seconds
Steadiness - As gun platform (Average = 50 %): 83 %
- Recoil effect (Restricted arc if above 1.00): 0.42
Seaboat quality (Average = 1.00): 1.32

Hull form characteristics:
Hull has a flush deck,
a normal bow and large transom stern
Block coefficient (normal/deep): 0.500 / 0.506
Length to Beam Ratio: 8.39 : 1
'Natural speed' for length: 32.14 kts
Power going to wave formation at top speed: 51 %
Trim (Max stability = 0, Max steadiness = 100): 63
Bow angle (Positive = bow angles forward): 22.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 22.00 %, 38.98 ft / 11.88 m, 27.89 ft / 8.50 m
- Forward deck: 18.00 %, 27.89 ft / 8.50 m, 21.33 ft / 6.50 m
- Aft deck: 38.00 %, 21.33 ft / 6.50 m, 21.33 ft / 6.50 m
- Quarter deck: 22.00 %, 21.33 ft / 6.50 m, 21.33 ft / 6.50 m
- Average freeboard: 24.34 ft / 7.42 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 75.9 %
- Above water (accommodation/working, high = better): 187.5 %
Waterplane Area: 49,074 Square feet or 4,559 Square metres
Displacement factor (Displacement / loading): 124 %
Structure weight / hull surface area: 152 lbs/sq ft or 740 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.98
- Longitudinal: 1.25
- Overall: 1.01
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

It basically gave up gun caliber in exchange for armor that could withstand 14" shells 19,000~30,000 yards and cruiser-level speed. The gamble was that foreign capital ships with 12" would barely be able to withstand 10+" shells, so Korea decided to reduce the gun caliber to divert the saved displacement for armor, and then secretly use superheavy APs to punch through the "pocket battleships". If the potential enemy were to have enough armor, then the main guns would be upgunned to superheavy 280 mm, with enough punching force to beat 14" shells, although this came at installing reduced machinery for a maximum speed of 28 knots (which was what actually happened in 1936).

I like how I managed to make this ship very good in all aspects. Working on the drawing now.

Both of those projects look very interesting.

Looking forward to seeing the results.

Heuksu-Class Main Force Cruiser


Full Resolution

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.


Commentary: This world's "large cruiser" are named "main force cruiser", and you can see the semi-consolidated superstructure design here would lead to the formation of the heavily armored Korean "Panok" design, as shown with the battleship Gwangmu.

Sumeragi re Heuksu-Class Main Force Cruiser,

Nice treaty killer should give any CA/PB a very bad time (just not sure you can hurt any proper BB but on 25k you cant do everything and yours looks nice and balanced and at 31.5KN it can run away).
IMO this would really upset a lot of admirals planing what to do to deal with this threat under a treaty environment.

I might personally change the blockier parts with life-rafts (and is you funnel wider than the block ?). I would also think that post war 40mm/70s are a bit to good AA for a 30s design (even quad 40/60 are pushing state of the art beyond believable for 34/36 IMO), you also have a light AA gun not on the specs near the stern ?

you can rip apart mine soon, JSB

The 28 cm armed version might be able to damage BBs through the deck, but then BBs should be handled by BBs.

What do you suggest?

Alternate history stuff, tech is around 3~5 years faster depending on the field.

Bugger, will remove those.