Japanese Design Concepts

[Desertfox]

You want some suitably large guns to properly intimidate the locals and to force the enemy to bring along capital ships instead of pre-dreads. The ship's role isn't to fight capital ships, its to be bait for those said capital ships.

[Jefgte]

You want some suitably large guns to properly intimidate the locals and to force the enemy to bring along capital ships instead of pre-dreads. The ship's role isn't to fight capital ships, its to be bait for those said capital ships.

it is rather to transform a heavy gunboat into pocket BC.
ACs would have a very serious opponent.

[TacCovert4]

Agreed.  And if you don't have triple 12s and only twin 12s, either do ABX, ABC, or AQY layouts.

[Kaiser Kirk]

Reminds me of various coast defense ships I've put forward, but those tended to be ~16000 with 2T3 setups and more armor.
I like the general concept, but I think pushing to make it that small it looses a little.
You may want to make sure the final Fire Control tonnage is sufficient.

[Desertfox]

Yall are right, the ship wasn't quite where it needed to be. Armor is overrated. Speed back up to 24kts and its under 9k! This one might actually get built.

Aki class, Japan Colonial Gunboat laid down 1921

Displacement:
   8,859 t light; 9,421 t standard; 10,046 t normal; 10,547 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (427.64 ft / 420.00 ft) x 70.00 ft x (23.00 / 23.88 ft)
   (130.35 m / 128.02 m) x 21.34 m  x (7.01 / 7.28 m)

Armament:
      4 - 14.00" / 356 mm 45.0 cal guns - 1,383.70lbs / 627.63kg shells, 100 per gun
     Breech loading guns in turret on barbette mounts, 1921 Model
     2 x Twin mounts on centreline ends, evenly spread
      12 - 5.00" / 127 mm 50.0 cal guns - 66.16lbs / 30.01kg shells, 120 per gun
     Quick firing guns in deck and hoist mounts, 1921 Model
     4 x Twin mounts on sides, evenly spread
     2 x Twin mounts on centreline ends, evenly spread
      2 raised mounts
      8 - 1.00" / 25.4 mm 70.0 cal guns - 0.56lbs / 0.25kg shells, 150 per gun
     Quick firing guns in deck mounts, 1921 Model
     4 x Twin mounts on sides, evenly spread
      4 raised mounts
      Weight of broadside 6,333 lbs / 2,873 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   7.00" / 178 mm   270.00 ft / 82.30 m   10.00 ft / 3.05 m
   Ends:   1.00" / 25 mm   150.00 ft / 45.72 m   10.00 ft / 3.05 m
     Main Belt covers 99 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   7.00" / 178 mm   3.00" / 76 mm      7.00" / 178 mm
   2nd:   1.00" / 25 mm         -         1.00" / 25 mm

   - Protected deck - multiple decks:
   For and Aft decks: 3.00" / 76 mm

   - Conning towers: Forward 7.00" / 178 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 33,039 shp / 24,647 Kw = 24.00 kts
   Range 5,000nm at 14.00 kts
   Bunker at max displacement = 1,126 tons

Complement:
   501 - 652

Cost:
   £2.724 million / $10.896 million

Distribution of weights at normal displacement:
   Armament: 1,132 tons, 11.3 %
      - Guns: 1,132 tons, 11.3 %
   Armour: 2,230 tons, 22.2 %
      - Belts: 885 tons, 8.8 %
      - Armament: 504 tons, 5.0 %
      - Armour Deck: 771 tons, 7.7 %
      - Conning Tower: 70 tons, 0.7 %
   Machinery: 1,138 tons, 11.3 %
   Hull, fittings & equipment: 4,004 tons, 39.9 %
   Fuel, ammunition & stores: 1,188 tons, 11.8 %
   Miscellaneous weights: 355 tons, 3.5 %
      - On freeboard deck: 240 tons
      - Above deck: 115 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     11,754 lbs / 5,332 Kg = 8.6 x 14.0 " / 356 mm shells or 1.8 torpedoes
   Stability (Unstable if below 1.00): 1.18
   Metacentric height 4.0 ft / 1.2 m
   Roll period: 14.8 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.79
   Seaboat quality  (Average = 1.00): 1.00

Hull form characteristics:
   Hull has low quarterdeck ,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.520 / 0.526
   Length to Beam Ratio: 6.00 : 1
   'Natural speed' for length: 20.49 kts
   Power going to wave formation at top speed: 58 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 20.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   30.00 %,  21.00 ft / 6.40 m,  17.00 ft / 5.18 m
      - Forward deck:   30.00 %,  17.00 ft / 5.18 m,  17.00 ft / 5.18 m
      - Aft deck:   20.00 %,  17.00 ft / 5.18 m,  17.00 ft / 5.18 m
      - Quarter deck:   20.00 %,  11.00 ft / 3.35 m,  11.00 ft / 3.35 m
      - Average freeboard:      16.28 ft / 4.96 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 90.6 %
      - Above water (accommodation/working, high = better): 129.0 %
   Waterplane Area: 19,952 Square feet or 1,854 Square metres
   Displacement factor (Displacement / loading): 95 %
   Structure weight / hull surface area: 152 lbs/sq ft or 740 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.89
      - Longitudinal: 2.63
      - Overall: 1.00
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room

115t -  Fire Control
25t - LR Wireless
25t - Observation Balloon
30t - Spare
160t - 4 x 20t boats/MTBs

[TacCovert4]

We spent so long thinking about if we could,  we never stopped to think if we should.

In the world of battlecruisers,  be a pre dreadnought....

[Kaiser Kirk]

Yall are right, the ship wasn't quite where it needed to be. Armor is overrated. Speed back up to 24kts and its under 9k! This one might actually get built.

Strictly as a technical issue, the way the combat system works is IF the shell penetrates the armor THEN it has a chance at a critical. Criticals are often serious damage. For non-dud rounds, there is a damage multiplier for those that penetrate intact.  Otherwise, there is a slow erosion of ship capability as damage accumulates.

In this case, the revised armor is roughly equivalent to older Parthian and Byzantine ACs, while I believe it is slightly faster than most Parthian and Byzantine dreadnaughts, and all our PDs.

[Desertfox]

I do have BCs to fight other BCs, this is mainly to beat up on PDs and ACs. Probably just build a couple for defense of Central America. The question is... what if I dump some more armor for say 27kts...?

[The Rock Doctor]

Find out and report back.

[Desertfox]

Saw this design, loved the idea, was like, why not?

https://www.deviantart.com/tzoli/art/IJN-Design-X-Light-Battlecruiser-Design-2-841032192

Orokamono, Japan Battle Scout laid down 1924

Displacement:
   9,991 t light; 10,539 t standard; 11,489 t normal; 12,248 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (670.00 ft / 670.00 ft) x 62.00 ft x (22.00 / 23.01 ft)
   (204.22 m / 204.22 m) x 18.90 m  x (6.71 / 7.01 m)

Armament:
      4 - 12.00" / 305 mm 50.0 cal guns - 914.66lbs / 414.88kg shells, 130 per gun
     Breech loading guns in turret on barbette mounts, 1924 Model
     4 x Single mounts on centreline, evenly spread
      8 - 5.00" / 127 mm 45.0 cal guns - 63.03lbs / 28.59kg shells, 190 per gun
     Quick firing guns in deck mounts, 1924 Model
     8 x Single mounts on sides, evenly spread
      8 - 1.00" / 25.4 mm 70.0 cal guns - 0.56lbs / 0.25kg shells, 150 per gun
     Machine guns in deck mounts, 1924 Model
     4 x Twin mounts on sides, evenly spread
      4 raised mounts
      4 - 1.00" / 25.4 mm 70.0 cal guns - 0.56lbs / 0.25kg shells, 150 per gun
     Anti-air guns in deck mounts, 1924 Model
     4 x Single mounts on sides, evenly spread
      4 raised mounts
      Weight of broadside 4,170 lbs / 1,891 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   5.00" / 127 mm   1.00" / 25 mm      5.00" / 127 mm
   2nd:   1.00" / 25 mm         -               -

   - Protected deck - single deck:
   For and Aft decks: 1.00" / 25 mm

   - Conning towers: Forward 5.00" / 127 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 107,481 shp / 80,181 Kw = 34.00 kts
   Range 7,200nm at 14.00 kts
   Bunker at max displacement = 1,709 tons

Complement:
   554 - 721

Cost:
   £3.863 million / $15.452 million

Distribution of weights at normal displacement:
   Armament: 978 tons, 8.5 %
      - Guns: 978 tons, 8.5 %
   Armour: 705 tons, 6.1 %
      - Armament: 343 tons, 3.0 %
      - Armour Deck: 308 tons, 2.7 %
      - Conning Tower: 55 tons, 0.5 %
   Machinery: 3,540 tons, 30.8 %
   Hull, fittings & equipment: 4,608 tons, 40.1 %
   Fuel, ammunition & stores: 1,497 tons, 13.0 %
   Miscellaneous weights: 160 tons, 1.4 %
      - On freeboard deck: 50 tons
      - Above deck: 110 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     7,449 lbs / 3,379 Kg = 8.6 x 12.0 " / 305 mm shells or 1.1 torpedoes
   Stability (Unstable if below 1.00): 1.15
   Metacentric height 3.2 ft / 1.0 m
   Roll period: 14.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.70
   Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.440 / 0.448
   Length to Beam Ratio: 10.81 : 1
   'Natural speed' for length: 25.88 kts
   Power going to wave formation at top speed: 53 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   40.00 %,  24.00 ft / 7.32 m,  17.00 ft / 5.18 m
      - Forward deck:   30.00 %,  17.00 ft / 5.18 m,  17.00 ft / 5.18 m
      - Aft deck:   15.00 %,  17.00 ft / 5.18 m,  17.00 ft / 5.18 m
      - Quarter deck:   15.00 %,  17.00 ft / 5.18 m,  17.00 ft / 5.18 m
      - Average freeboard:      18.12 ft / 5.52 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 132.0 %
      - Above water (accommodation/working, high = better): 153.6 %
   Waterplane Area: 26,286 Square feet or 2,442 Square metres
   Displacement factor (Displacement / loading): 97 %
   Structure weight / hull surface area: 122 lbs/sq ft or 595 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.98
      - Longitudinal: 1.15
      - Overall: 1.00
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room

110t - Fire Control/LR Wireless
50t - 12 x 21" (H) Torpedo Tubes

[The Rock Doctor]

Yeah, that's definitely a Desertfox design.

[Jefgte]

Original & intersecting design.
Certainly a good raider.

[Desertfox]

I just realized the design I posted has no armor... Which is actually a mistake and not a design point. Also the engineer who came up with the original design was very optimistic, no way can this ship hit 36kts.

[The Rock Doctor]

I assumed the lack of armor was intentional, actually.

[TacCovert4]

Can't detonate heavy caliber HE if the fuzes never initiate.....