Japanese Ship Designs 1912+

[Desertfox]

According to the rules 210mm and smaller guns come with a free deck mount. The rules also only mention "refreshing" which is an upgrade to the gun not a downgrade. If I have to develop an 8/35, it comes out to $1 and 1 year, which makes no sense when all thats happening is taking two existing guns and chopping the ends off. They are not even new built guns. Just basically storyline fodder for ships that have the combat capability of a transport. Frankly speaking I have a better cheaper gunboat with twin 5" guns, I was planning to build anyways.


Hashidate, Japan Gun Boat laid down 1914

Displacement:
   249 t light; 268 t standard; 291 t normal; 310 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (200.00 ft / 200.00 ft) x 25.00 ft x (4.00 / 4.20 ft)
   (60.96 m / 60.96 m) x 7.62 m  x (1.22 / 1.28 m)

Armament:
      2 - 5.00" / 127 mm 45.0 cal guns - 63.03lbs / 28.59kg shells, 150 per gun
     Quick firing guns in deck mounts, 1914 Model
     2 x Single mounts on centreline, evenly spread
      6 - 2.00" / 50.8 mm 45.0 cal guns - 4.03lbs / 1.83kg shells, 200 per gun
     Quick firing guns in deck mounts, 1914 Model
     2 x Triple mounts on sides amidships
      Weight of broadside 150 lbs / 68 kg

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

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 2 shafts, 1,254 shp / 936 Kw = 17.00 kts
   Range 2,500nm at 10.00 kts
   Bunker at max displacement = 42 tons

Complement:
   34 - 45

Cost:
   £0.029 million / $0.116 million

Distribution of weights at normal displacement:
   Armament: 26 tons, 9.0 %
      - Guns: 26 tons, 9.0 %
   Armour: 10 tons, 3.3 %
      - Armament: 10 tons, 3.3 %
   Machinery: 48 tons, 16.6 %
   Hull, fittings & equipment: 123 tons, 42.1 %
   Fuel, ammunition & stores: 43 tons, 14.6 %
   Miscellaneous weights: 42 tons, 14.4 %
      - Hull below water: 12 tons
      - On freeboard deck: 25 tons
      - Above deck: 5 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     563 lbs / 255 Kg = 9.0 x 5.0 " / 127 mm shells or 0.5 torpedoes
   Stability (Unstable if below 1.00): 1.21
   Metacentric height 0.9 ft / 0.3 m
   Roll period: 11.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.30
   Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.510 / 0.518
   Length to Beam Ratio: 8.00 : 1
   'Natural speed' for length: 14.14 kts
   Power going to wave formation at top speed: 49 %
   Trim (Max stability = 0, Max steadiness = 100): 67
   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:   20.00 %,  7.00 ft / 2.13 m,  7.00 ft / 2.13 m
      - Forward deck:   30.00 %,  7.00 ft / 2.13 m,  7.00 ft / 2.13 m
      - Aft deck:   35.00 %,  7.00 ft / 2.13 m,  7.00 ft / 2.13 m
      - Quarter deck:   15.00 %,  7.00 ft / 2.13 m,  7.00 ft / 2.13 m
      - Average freeboard:      7.00 ft / 2.13 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 84.7 %
      - Above water (accommodation/working, high = better): 131.8 %
   Waterplane Area: 3,362 Square feet or 312 Square metres
   Displacement factor (Displacement / loading): 134 %
   Structure weight / hull surface area: 31 lbs/sq ft or 152 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.87
      - Longitudinal: 1.24
      - Overall: 0.90
   Caution: Hull subject to strain in open-sea
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

5t - FC
25t - Observation Balloon/Marines/Mine Gear/Etc
12t - Electric Drive

[Kaiser Kirk]

According to the rules 210mm and smaller guns come with a free deck mount. The rules also only mention "refreshing" which is an upgrade to the gun not a downgrade. If I have to develop an 8/35, it comes out to $1 and 1 year, which makes no sense when all thats happening is taking two existing guns and chopping the ends off. They are not even new built guns. Just basically storyline fodder for ships that have the combat capability of a transport. Frankly speaking I have a better cheaper gunboat with twin 5" guns, I was planning to build anyways.

Actually refreshing includes relining a gun to a smaller size, or boring it out, or otherwise modifying an existing gun into a new gun. The changes are explicitly subject to review.

Refreshing would be the clause that would enable you to chop down the gun and reset the trunions or otherwise rebalance it, band the shortened muzzle to replace the muzzle bell you cut off,  establish new ballistics tables etc.  With an 1896 gun, you'd likely want to fit a better breech as well, and rejig the hoist system. You would also need to refresh the M&H for the 8/40 to turn it into the 8/35. If you do not have a M&H specified for an 8/40 you have to develop it.

[Desertfox]

So it really doesn't make sense to downgrade weapons, since its just as expensive as developing new ones... There should be exceptions for when the end result is clearly inferior to what you started with.


Using the 200t minesweeper hull as a base resulted in a superior gunboat design...

Hashidate 2.0, Japan Gun Boat laid down 1914

Displacement:
   200 t light; 214 t standard; 233 t normal; 248 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (156.59 ft / 155.00 ft) x 21.00 ft x (5.00 / 5.24 ft)
   (47.73 m / 47.24 m) x 6.40 m  x (1.52 / 1.60 m)

Armament:
      6 - 2.00" / 50.8 mm 45.0 cal guns - 4.03lbs / 1.83kg shells, 170 per gun
     Quick firing guns in deck mounts, 1914 Model
     2 x Triple mounts on centreline, evenly spread
      2 - 5.00" / 127 mm 45.0 cal guns - 63.03lbs / 28.59kg shells, 100 per gun
     Quick firing guns in deck mounts, 1914 Model
     2 x Single mounts on centreline, evenly spread
      Weight of broadside 150 lbs / 68 kg

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

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 2 shafts, 1,174 shp / 876 Kw = 17.00 kts
   Range 2,400nm at 10.00 kts
   Bunker at max displacement = 34 tons

Complement:
   29 - 38

Cost:
   £0.026 million / $0.105 million

Distribution of weights at normal displacement:
   Armament: 26 tons, 11.3 %
      - Guns: 26 tons, 11.3 %
   Armour: 5 tons, 2.2 %
      - Armament: 5 tons, 2.2 %
   Machinery: 45 tons, 19.4 %
   Hull, fittings & equipment: 79 tons, 34.0 %
   Fuel, ammunition & stores: 33 tons, 14.1 %
   Miscellaneous weights: 44 tons, 18.9 %
      - Hull below water: 11 tons
      - On freeboard deck: 30 tons
      - Above deck: 3 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     336 lbs / 152 Kg = 84.0 x 2.0 " / 51 mm shells or 0.4 torpedoes
   Stability (Unstable if below 1.00): 1.25
   Metacentric height 0.7 ft / 0.2 m
   Roll period: 10.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.47
   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): 0.500 / 0.508
   Length to Beam Ratio: 7.38 : 1
   'Natural speed' for length: 12.45 kts
   Power going to wave formation at top speed: 59 %
   Trim (Max stability = 0, Max steadiness = 100): 49
   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 %,  9.00 ft / 2.74 m,  7.00 ft / 2.13 m
      - Forward deck:   30.00 %,  7.00 ft / 2.13 m,  7.00 ft / 2.13 m
      - Aft deck:   30.00 %,  7.00 ft / 2.13 m,  7.00 ft / 2.13 m
      - Quarter deck:   20.00 %,  7.00 ft / 2.13 m,  7.00 ft / 2.13 m
      - Average freeboard:      7.16 ft / 2.18 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 99.1 %
      - Above water (accommodation/working, high = better): 99.7 %
   Waterplane Area: 2,169 Square feet or 201 Square metres
   Displacement factor (Displacement / loading): 111 %
   Structure weight / hull surface area: 29 lbs/sq ft or 143 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.81
      - Longitudinal: 2.23
      - Overall: 0.90
   Caution: Hull subject to strain in open-sea
   Adequate machinery, storage, compartmentation space
   Adequate accommodation and workspace room

3t - FC
30t - Observation Balloon/Marines/Mine Gear Etc
11t - Electric Drive

[The Rock Doctor]

I didn't really understand the rationale behind cutting down the 8" gun in the first place - the extra 40" of barrel length didn't seem problematic from a deck space perspective.

[Desertfox]

It was a matter of function, the high muzzle velocity of the 8/45 was not required on a shore bombardment gun and lowering it would reduce stress on the ship, allow for higher angles, and allow the use of thin skin, high explosive content shells, plus also reduced the weight of the gun and mount. 

[TacCovert4]

I might suggest that something along the lines of the 5in/25 or so could be developed as a light shore-bombardment gun.  Which could later segue into an AA gun in time.

[Desertfox]

Refit of the Uji class. main gun upgraded to 5" and the exploration areas changed to support an observation balloon and minesweeping gear added.

Uji class, Japan Multi-purpose Colonial Auxiliary Ship laid down 1907

Displacement:
   698 t light; 725 t standard; 885 t normal; 1,013 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (270.00 ft / 270.00 ft) x 31.00 ft x (7.40 / 8.20 ft)
   (82.30 m / 82.30 m) x 9.45 m  x (2.26 / 2.50 m)

Armament:
      1 - 5.00" / 127 mm 45.0 cal gun - 63.03lbs / 28.59kg shells, 200 per gun
     Quick firing gun in deck mount, 1914 Model
     1 x Single mount on centreline, forward deck centre
      3 - 2.00" / 50.8 mm 45.0 cal guns - 4.03lbs / 1.83kg shells, 300 per gun
     Quick firing guns in deck mount, 1907 Model
     1 x Triple mount on centreline, aft deck centre
      1 raised mount
      Weight of broadside 75 lbs / 34 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.50" / 13 mm         -               -
   2nd:   0.50" / 13 mm         -               -

   - Conning towers: Forward 1.00" / 25 mm, Aft 0.00" / 0 mm

Machinery:
   Coal and oil fired boilers, complex reciprocating steam engines,
   Direct drive, 2 shafts, 2,161 ihp / 1,612 Kw = 17.00 kts
   Range 5,700nm at 10.00 kts
   Bunker at max displacement = 288 tons (90% coal)

Complement:
   80 - 105

Cost:
   £0.061 million / $0.246 million

Distribution of weights at normal displacement:
   Armament: 13 tons, 1.5 %
      - Guns: 13 tons, 1.5 %
   Armour: 4 tons, 0.5 %
      - Armament: 2 tons, 0.3 %
      - Conning Tower: 2 tons, 0.2 %
   Machinery: 238 tons, 26.9 %
   Hull, fittings & equipment: 318 tons, 35.9 %
   Fuel, ammunition & stores: 187 tons, 21.1 %
   Miscellaneous weights: 125 tons, 14.1 %
      - On freeboard deck: 70 tons
      - Above deck: 55 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1,454 lbs / 660 Kg = 23.3 x 5.0 " / 127 mm shells or 0.7 torpedoes
   Stability (Unstable if below 1.00): 1.34
   Metacentric height 1.5 ft / 0.4 m
   Roll period: 10.8 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.08
   Seaboat quality  (Average = 1.00): 1.50

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.500 / 0.516
   Length to Beam Ratio: 8.71 : 1
   'Natural speed' for length: 16.43 kts
   Power going to wave formation at top speed: 42 %
   Trim (Max stability = 0, Max steadiness = 100): 47
   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:   35.00 %,  11.00 ft / 3.35 m,  9.00 ft / 2.74 m
      - Forward deck:   30.00 %,  9.00 ft / 2.74 m,  9.00 ft / 2.74 m
      - Aft deck:   20.00 %,  9.00 ft / 2.74 m,  9.00 ft / 2.74 m
      - Quarter deck:   15.00 %,  9.00 ft / 2.74 m,  9.00 ft / 2.74 m
      - Average freeboard:      9.28 ft / 2.83 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 92.3 %
      - Above water (accommodation/working, high = better): 119.5 %
   Waterplane Area: 5,577 Square feet or 518 Square metres
   Displacement factor (Displacement / loading): 138 %
   Structure weight / hull surface area: 40 lbs/sq ft or 197 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 1.00
      - Longitudinal: 1.19
      - Overall: 1.01
   Adequate machinery, storage, compartmentation space
   Adequate accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

25t - 1 x LR wireless,
25t - 1 x Experimental Radar,
5t - FC and Flagship Facilities
20t - Observation Balloon Equipment
20t - 2 x 5t boats
20t - 10 x Marines
10t - Minesweeping Gear

[eltf177]

What are the specs of the original "Uji"-class?

[Desertfox]

Basically the same just a 3" gun, and different misc weights: https://www.navalism.org/index.php/topic,7295.0.html