Ok, I've decided to quickly land something here because.. dunno.. let's say that Koko briefly contemplated a much smaller first Dreadnought Battleship before ditching the idea and starting to focus on what will later become the much larger and powerful (and even faster) Yagumo class.
Here is the 1908-1909 proposal:
1908-1909 study, Koko Battleship laid down 1909
Displacement:
15.985 t light; 16.786 t standard; 18.779 t normal; 20.373 t full load
Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(536,09 ft / 521,00 ft) x 82,02 ft x (26,25 / 28,06 ft)
(163,40 m / 158,80 m) x 25,00 m x (8,00 / 8,55 m)
Armament:
6 - 12,01" / 305 mm 50,0 cal guns - 850,98lbs / 386,00kg shells, 100 per gun
Breech loading guns in turret on barbette mounts, 1905 Model
3 x Twin mounts on centreline ends, majority aft
1 raised mount aft - superfiring
12 - 5,98" / 152 mm 50,0 cal guns - 100,00lbs / 45,36kg shells, 150 per gun
Breech loading guns in casemate mounts, 1910 Model
12 x Single mounts on sides, evenly spread
12 hull mounts in casemates- Limited use in heavy seas
4 - 5,98" / 152 mm 40,0 cal guns - 100,00lbs / 45,36kg shells, 150 per gun
Breech loading guns in deck mounts, 1906 Model
4 x Single mounts on sides, evenly spread
6 - 2,99" / 76,0 mm 40,0 cal guns - 12,50lbs / 5,67kg shells, 200 per gun
Breech loading guns in deck mounts, 1908 Model
6 x Single mounts on sides, evenly spread
4 raised mounts
Weight of broadside 6.781 lbs / 3.076 kg
Main Torpedoes
8 - 17,7" / 450 mm, 16,70 ft / 5,09 m torpedoes - 0,779 t each, 6,232 t total
submerged side tubes
2nd Torpedoes
4 - 17,7" / 450 mm, 16,70 ft / 5,09 m torpedoes - 0,779 t each, 3,116 t total
submerged stern tubes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 12,0" / 305 mm 313,42 ft / 95,53 m 15,88 ft / 4,84 m
Ends: 5,00" / 127 mm 207,55 ft / 63,26 m 8,01 ft / 2,44 m
Upper: 5,98" / 152 mm 216,77 ft / 66,07 m 16,47 ft / 5,02 m
Main Belt covers 93% of normal length
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 11,0" / 279 mm 2,99" / 76 mm 9,02" / 229 mm
2nd: 5,98" / 152 mm - -
3rd: 5,98" / 152 mm - -
- Armoured deck - multiple decks:
For and Aft decks: 2,01" / 51 mm
- Conning towers: Forward 10,00" / 254 mm, Aft 10,00" / 254 mm
Machinery:
Coal fired boilers, steam turbines,
Direct drive, 2 shafts, 38.466 shp / 28.695 Kw = 23,00 kts
Range 2.700nm at 18,00 kts
Bunker at max displacement = 3.587 tons (100% coal)
Complement:
801 - 1.042
Cost:
£1,491 million / $5,965 million
Distribution of weights at normal displacement:
Armament: 1.396 tons, 7,4%
- Guns: 1.377 tons, 7,3%
- Weapons: 19 tons, 0,1%
Armour: 6.360 tons, 33,9%
- Belts: 4.014 tons, 21,4%
- Armament: 1.152 tons, 6,1%
- Armour Deck: 890 tons, 4,7%
- Conning Towers: 304 tons, 1,6%
Machinery: 1.923 tons, 10,2%
Hull, fittings & equipment: 6.106 tons, 32,5%
Fuel, ammunition & stores: 2.794 tons, 14,9%
Miscellaneous weights: 200 tons, 1,1%
- Hull above water: 100 tons
- On freeboard deck: 100 tons
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
31.488 lbs / 14.283 Kg = 36,4 x 12,0 " / 305 mm shells or 5,7 torpedoes
Stability (Unstable if below 1.00): 1,18
Metacentric height 5,0 ft / 1,5 m
Roll period: 15,4 seconds
Steadiness - As gun platform (Average = 50 %): 82 %
- Recoil effect (Restricted arc if above 1.00): 0,71
Seaboat quality (Average = 1.00): 1,64
Hull form characteristics:
Hull has rise forward of midbreak,
a normal bow and a round stern
Block coefficient (normal/deep): 0,586 / 0,595
Length to Beam Ratio: 6,35 : 1
'Natural speed' for length: 22,83 kts
Power going to wave formation at top speed: 51 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 18,00 degrees
Stern overhang: 6,00 ft / 1,83 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 19,54%, 27,99 ft / 8,53 m, 26,97 ft / 8,22 m
- Forward deck: 35,15%, 26,97 ft / 8,22 m, 26,48 ft / 8,07 m
- Aft deck: 25,01%, 17,49 ft / 5,33 m, 17,98 ft / 5,48 m
- Quarter deck: 20,30%, 17,98 ft / 5,48 m, 19,49 ft / 5,94 m
- Average freeboard: 22,98 ft / 7,00 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 67,2%
- Above water (accommodation/working, high = better): 168,6%
Waterplane Area: 30.847 Square feet or 2.866 Square metres
Displacement factor (Displacement / loading): 112%
Structure weight / hull surface area: 145 lbs/sq ft or 710 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,91
- Longitudinal: 2,29
- Overall: 1,00
Excellent machinery, storage, compartmentation space
Excellent accommodation and workspace room
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather