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Japanese Coastal Warship

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By Tzoli   |   
Published:
© 2015 - 2020 Tzoli
A fictional design of a small, big gun armed warship for the Imperial Japanese Navy I've made for my Japanese friend.
As IJN only built 2 similar but much smaller vessels for Thailand and nothing for it's own navy we don't know what kind of names would be allocated to these kind of vessels. My friend suggested battleship names, but I think maybe gorges are a nice addition to the names of IJN, so I decided to call this vessel Shosen-kyo class coastal defence battleship.

The ships use salvaged turrets and 30cm guns from the Settsu class battleships and the turrets and 15,5cm guns intended for the Tone class cruisers. Heavy AA provided by the 12,7cm Type 89 guns and light AA by the 25mm Type 96 machine guns.

Used tool: Paint Tool SAI

Coloured version can be found here:
tzoli.deviantart.com/art/Shose…

Calculations:

IJN Shosen-kyo, Japanese Coastal defence warship laid down 1937 (Engine 1938)

Displacement:
    7 695 t light; 8 282 t standard; 8 709 t normal; 9 049 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
    (396,82 ft / 392,72 ft) x 61,02 ft (Bulges 64,30 ft) x (22,31 / 23,00 ft)
    (120,95 m / 119,70 m) x 18,60 m (Bulges 19,60 m)  x (6,80 / 7,01 m)

Armament:
      4 - 12,01" / 305 mm 50,0 cal guns - 850,98lbs / 386,00kg shells, 150 per gun
      Breech loading guns in turret on barbette mounts, 1905 Model
      2 x 2-gun mounts on centreline, evenly spread
      6 - 6,10" / 155 mm 60,0 cal guns - 123,17lbs / 55,87kg shells, 150 per gun
      Breech loading guns in turret on barbette mounts, 1930 Model
      2 x 3-gun mounts on centreline, evenly spread
        2 raised mounts
      8 - 5,00" / 127 mm 40,0 cal guns - 51,70lbs / 23,45kg shells, 200 per gun
      Dual purpose guns in deck and hoist mounts, 1929 Model
      4 x Twin mounts on sides, evenly spread
      38 - 0,98" / 25,0 mm 60,0 cal guns - 0,52lbs / 0,24kg shells, 2 000 per gun
      Anti-air guns in deck mounts, 1935 Model
      10 x Triple mounts on sides, evenly spread
        4 raised mounts
      4 x Twin mounts on sides, evenly spread
        4 raised mounts
      Weight of broadside 4 576 lbs / 2 076 kg

Armour:
   - Belts:        Width (max)    Length (avg)        Height (avg)
    Main:    7,87" / 200 mm    255,25 ft / 77,80 m    9,38 ft / 2,86 m
    Ends:    2,36" / 60 mm    137,43 ft / 41,89 m    9,38 ft / 2,86 m
    Upper:    3,94" / 100 mm    255,25 ft / 77,80 m    8,01 ft / 2,44 m
      Main Belt covers 100 % of normal length

   - Torpedo Bulkhead - Strengthened structural bulkheads:
        4,13" / 105 mm    255,25 ft / 77,80 m    20,28 ft / 6,18 m
    Beam between torpedo bulkheads 61,02 ft / 18,60 m

   - Hull Bulges:
        1,97" / 50 mm    246,06 ft / 75,00 m    16,40 ft / 5,00 m

   - Gun armour:    Face (max)    Other gunhouse (avg)    Barbette/hoist (max)
    Main:    11,0" / 280 mm    7,99" / 203 mm        11,0" / 280 mm
    2nd:    0,98" / 25 mm    0,98" / 25 mm        0,98" / 25 mm
    3rd:    0,20" / 5 mm    0,20" / 5 mm        0,20" / 5 mm

   - Box over machinery & magazines:
    2,99" / 76 mm
    Forecastle: 0,98" / 25 mm  Quarter deck: 0,98" / 25 mm

   - Conning towers: Forward 4,02" / 102 mm, Aft 4,02" / 102 mm

Machinery:
    Oil fired boilers, steam turbines,
    Geared drive, 2 shafts, 21 793 shp / 16 257 Kw = 22,50 kts
    Range 3 500nm at 14,00 kts
    Bunker at max displacement = 767 tons

Complement:
    449 - 585

Overall survivability and seakeeping ability:
    Survivability (Non-critical penetrating hits needed to sink ship):
      10 623 lbs / 4 819 Kg = 12,3 x 12,0 " / 305 mm shells or 2,5 torpedoes
    Metacentric height 2,7 ft / 0,8 m
    Roll period: 16,5 seconds

Hull form characteristics:
    Hull has rise forward of midbreak,
      a normal bow and large transom stern
    'Natural speed' for length: 23,48 kts
    Power going to wave formation at top speed: 57 %
    Trim (Max stability = 0, Max steadiness = 100): 55

Ship space, strength and comments:
    Waterplane Area: 17 263 Square feet or 1 604 Square metres
    Displacement factor (Displacement / loading): 89 %
    Structure weight / hull surface area: 140 lbs/sq ft or 682 Kg/sq metre
    Excellent machinery, storage, compartmentation space
    Adequate accommodation and workspace room
Image size
2656x1400px 526.73 KB
Comments51
anonymous's avatar
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Welfen's avatar
Hello, I'm Japanese. This ship is very interesting. Awesome work.
I thought if she waste two secondary 155mm turret, can she have space to have one more main 305mm turret?
But if she can do this, ship's weight will increase and speed would be down.
Tzoli's avatar
TzoliHobbyist Digital Artist
There is not enough space for a 3rd Settsu turret. But I've made an alternative late war version with more AA guns:
tzoli.deviantart.com/art/Japan…
tzoli.deviantart.com/art/Shose…
Welfen's avatar
Thank you for answer. AA ver looks very good.
Tzoli's avatar
TzoliHobbyist Digital Artist
Thanks and welcome!
Midway2009's avatar
Midway2009Hobbyist Traditional Artist
Awesome. :wow:
MacPaul's avatar
Very cool!
Delaney8's avatar
You know, at 9000 tons fully loaded it's more of an actual pre-dreadnought than a coastal defence ship... the Sveriges were 7750 tonsand they were possibly the biggest of their kind; the finnish Ilmarinen and Vainamoinen were around 4000 tons and the thai Dhonburi were even smaller... But we know the japs had the "if it's worth doing it's worth overdoing" mentality, so these would actually be the equivalents of the Yamatos among coastal battleships
Tzoli's avatar
TzoliHobbyist Digital Artist
I think a Yamato equivalent of the Coastal warships should be in the 10K displacement region, with around 32cm+ armour and 35-41cm cannons.
Delaney8's avatar
Maybe, but these are actually pretty close...
zkfanart's avatar
Very interesting ^^ Coast defence vessels are not much remembered..... how much is their displacement, at least in full load and the speed?
Tzoli's avatar
TzoliHobbyist Digital Artist
Added the calculations, but the displacement is roughly 1000-1300tons heavier that of the Sverige.
zkfanart's avatar
aw, more or less 8,000 tons.... we could, a bit round numbers, go up to 10,000 tons - almost like a pocket batleship.
Tzoli's avatar
TzoliHobbyist Digital Artist
Which is a big gun cruiser
zkfanart's avatar
Yes. Almost the upper limit for the Washington Treaty heavy cruisers.
Tzoli's avatar
TzoliHobbyist Digital Artist
Which after 1936  is nullified for Japan and Italy
leovictor's avatar
You know you can go smaller.
Try monitors
Tzoli's avatar
TzoliHobbyist Digital Artist
I know but I'm not sure the guy likes monitors and also they are very slow and even shorter ranged
Siveir's avatar
So far it's looking good, though I'm not fond of 2x2 designs (later then original pre-dreadnoughts of course)...
Tzoli's avatar
TzoliHobbyist Digital Artist
You have to stay small with coastal warships.
Siveir's avatar
Well IMHO in coastal defence, aircrafts and submarines are better choice than gunship
Tzoli's avatar
TzoliHobbyist Digital Artist
Partly, you still need guns for bombardment.
Siveir's avatar
Of you own coast? For a bombardament you need something that can aslo project power over the open ocean, so no coastal design. I'm not saying it's not a nice ship, it's just impractical ;)
Tzoli's avatar
TzoliHobbyist Digital Artist
The person required said it was for the Chinese Area Fleet. And of course you can use it to bombard Indian or Soviet coastal areas while the important battleships are out there searching for surface fleets.
Siveir's avatar
Still, I'm not fan
anonymous's avatar
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