Gunboats

[Walter]

Gunboat Size Comparison.

Top to bottom: Uji, Tsukushi.

[Walter]

Maya, Japan Gunboat class 2 laid down 1885


Ships: Maya, Chokai, Atago, Akagi
Displacement:
   490 t light; 528 t standard; 602 t normal; 662 t full load

Dimensions: Length overall / water x beam x draught
   154.20 ft / 154.20 ft x 26.90 ft x 9.68 ft (normal load)
   47.00 m / 47.00 m x 8.20 m  x 2.95 m

Armament:
      1 - 8.20" / 208 mm guns in single mounts, 255.01lbs / 115.67kg shells, 1885 Model
     Breech loading gun in deck mount
     on centreline forward
      1 - 4.72" / 120 mm guns in single mounts, 48.77lbs / 22.12kg shells, 1885 Model
     Quick firing gun in deck mount
     on side amidships
   Weight of broadside 304 lbs / 138 kg
   Shells per gun, main battery: 150
   3 - 17.7" / 450 mm submerged torpedo tubes

Machinery:
   Coal fired boilers, simple reciprocating steam engines,
   Direct drive, 2 shafts, 334 ihp / 249 Kw = 10.40 kts
   Range 2,000nm at 10.00 kts
   Bunker at max displacement = 134 tons (100% coal)

Complement:
   60 - 79

Cost:
   £0.058 million / $0.232 million

Distribution of weights at normal displacement:
   Armament: 38 tons, 6.3 %
   Machinery: 65 tons, 10.8 %
   Hull, fittings & equipment: 337 tons, 55.9 %
   Fuel, ammunition & stores: 113 tons, 18.7 %
   Miscellaneous weights: 50 tons, 8.3 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     368 lbs / 167 Kg = 1.4 x 8.2 " / 208 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.20
   Metacentric height 1.0 ft / 0.3 m
   Roll period: 11.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 100 %
         - Recoil effect (Restricted arc if above 1.00): 0.48
   Seaboat quality  (Average = 1.00): 1.68

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.525
   Length to Beam Ratio: 5.73 : 1
   'Natural speed' for length: 12.42 kts
   Power going to wave formation at top speed: 39 %
   Trim (Max stability = 0, Max steadiness = 100): 60
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      6.56 ft / 2.00 m
      - Forecastle (20 %):   6.56 ft / 2.00 m
      - Mid (50 %):      6.56 ft / 2.00 m
      - Quarterdeck (15 %):   6.56 ft / 2.00 m
      - Stern:      6.56 ft / 2.00 m
      - Average freeboard:   6.56 ft / 2.00 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 124.9 %
      - Above water (accommodation/working, high = better): 58.9 %
   Waterplane Area: 2,828 Square feet or 263 Square metres
   Displacement factor (Displacement / loading): 125 %
   Structure weight / hull surface area: 79 lbs/sq ft or 385 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 1.53
      - Longitudinal: 4.48
      - Overall: 1.70
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is cramped
   Ship has slow, easy roll, a good, steady gun platform
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

[Walter]

Oshima, Japan Gunboat class 2 laid down 1889

Displacement:
   531 t light; 563 t standard; 629 t normal; 682 t full load

Dimensions: Length overall / water x beam x draught
   177.17 ft / 177.17 ft x 26.25 ft x 9.02 ft (normal load)
   54.00 m / 54.00 m x 8.00 m  x 2.75 m

Armament:
      4 - 4.72" / 120 mm guns (1x4 guns), 51.93lbs / 23.56kg shells, 1889 Model
     Breech loading guns in deck mount
     on centreline forward
      5 - 1.85" / 47.0 mm guns (1x5 guns), 3.12lbs / 1.42kg shells, 1889 Model
     Quick firing guns in deck mount
     on side amidships
   Weight of broadside 223 lbs / 101 kg
   Shells per gun, main battery: 150

Machinery:
   Coal fired boilers, simple reciprocating steam engines,
   Direct drive, 2 shafts, 1,644 ihp / 1,227 Kw = 16.00 kts
   Range 2,000nm at 10.00 kts
   Bunker at max displacement = 120 tons (100% coal)

Complement:
   62 - 81

Cost:
   £0.074 million / $0.297 million

Distribution of weights at normal displacement:
   Armament: 28 tons, 4.4 %
   Machinery: 231 tons, 36.7 %
   Hull, fittings & equipment: 222 tons, 35.3 %
   Fuel, ammunition & stores: 98 tons, 15.6 %
   Miscellaneous weights: 50 tons, 7.9 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     280 lbs / 127 Kg = 5.4 x 4.7 " / 120 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.15
   Metacentric height 0.9 ft / 0.3 m
   Roll period: 11.8 seconds
   Steadiness   - As gun platform (Average = 50 %): 100 %
         - Recoil effect (Restricted arc if above 1.00): 0.48
   Seaboat quality  (Average = 1.00): 1.30

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.525
   Length to Beam Ratio: 6.75 : 1
   'Natural speed' for length: 13.31 kts
   Power going to wave formation at top speed: 56 %
   Trim (Max stability = 0, Max steadiness = 100): 77
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      8.20 ft / 2.50 m
      - Forecastle (20 %):   8.20 ft / 2.50 m
      - Mid (50 %):      8.20 ft / 2.50 m
      - Quarterdeck (15 %):   8.20 ft / 2.50 m
      - Stern:      8.20 ft / 2.50 m
      - Average freeboard:   8.20 ft / 2.50 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 161.1 %
      - Above water (accommodation/working, high = better): 79.9 %
   Waterplane Area: 3,170 Square feet or 295 Square metres
   Displacement factor (Displacement / loading): 69 %
   Structure weight / hull surface area: 44 lbs/sq ft or 216 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.92
      - Longitudinal: 2.52
      - Overall: 1.02
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is cramped
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

[Walter]

Uji, Japan Gunboat class 2 laid down 1902

Displacement:
   492 t light; 508 t standard; 598 t normal; 670 t full load

Dimensions: Length overall / water x beam x draught
   183.73 ft / 183.73 ft x 27.56 ft x 6.89 ft (normal load)
   56.00 m / 56.00 m x 8.40 m  x 2.10 m

Armament:
      4 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1902 Model
     Breech loading guns in deck mounts
     on centreline ends, evenly spread
   Weight of broadside 54 lbs / 24 kg
   Shells per gun, main battery: 150

Machinery:
   Coal fired boilers, complex reciprocating steam engines,
   Direct drive, 1 shaft, 1,000 ihp / 746 Kw = 14.14 kts
   Range 3,500nm at 10.00 kts
   Bunker at max displacement = 162 tons (100% coal)

Complement:
   59 - 78

Cost:
   £0.044 million / $0.176 million

Distribution of weights at normal displacement:
   Armament: 7 tons, 1.1 %
   Machinery: 151 tons, 25.3 %
   Hull, fittings & equipment: 183 tons, 30.7 %
   Fuel, ammunition & stores: 106 tons, 17.8 %
   Miscellaneous weights: 150 tons, 25.1 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     548 lbs / 248 Kg = 40.6 x 3.0 " / 76 mm shells or 0.4 torpedoes
   Stability (Unstable if below 1.00): 1.12
   Metacentric height 0.9 ft / 0.3 m
   Roll period: 12.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 100 %
         - Recoil effect (Restricted arc if above 1.00): 0.11
   Seaboat quality  (Average = 1.00): 1.55

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.600
   Length to Beam Ratio: 6.67 : 1
   'Natural speed' for length: 13.55 kts
   Power going to wave formation at top speed: 49 %
   Trim (Max stability = 0, Max steadiness = 100): 65
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      8.20 ft / 2.50 m
      - Forecastle (20 %):   8.20 ft / 2.50 m
      - Mid (50 %):      8.20 ft / 2.50 m
      - Quarterdeck (15 %):   8.20 ft / 2.50 m
      - Stern:      8.20 ft / 2.50 m
      - Average freeboard:   8.20 ft / 2.50 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 118.1 %
      - Above water (accommodation/working, high = better): 95.9 %
   Waterplane Area: 3,622 Square feet or 337 Square metres
   Displacement factor (Displacement / loading): 118 %
   Structure weight / hull surface area: 35 lbs/sq ft or 170 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.96
      - Longitudinal: 1.76
      - Overall: 1.02
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is adequate
   Ship has slow, easy roll, a good, steady gun platform
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

[Walter]

Sumida, Japan Gunboat class 2 laid down 1903

Displacement:
   133 t light; 137 t standard; 155 t normal; 170 t full load

Dimensions: Length overall / water x beam x draught
   144.36 ft / 144.36 ft x 22.97 ft x 3.28 ft (normal load)
   44.00 m / 44.00 m x 7.00 m  x 1.00 m

Armament:
      2 - 1.85" / 47.0 mm guns in single mounts, 3.17lbs / 1.44kg shells, 1903 Model
     Breech loading guns in deck mounts
     on centreline ends, evenly spread
   Weight of broadside 6 lbs / 3 kg
   Shells per gun, main battery: 150

Machinery:
   Coal fired boilers, complex reciprocating steam engines,
   Direct drive, 3 shafts, 256 ihp / 191 Kw = 12.00 kts
   Range 1,500nm at 10.00 kts
   Bunker at max displacement = 33 tons (100% coal)

Complement:
   21 - 28

Cost:
   £0.011 million / $0.043 million

Distribution of weights at normal displacement:
   Armament: 1 tons, 0.5 %
   Machinery: 38 tons, 24.6 %
   Hull, fittings & equipment: 74 tons, 47.9 %
   Fuel, ammunition & stores: 22 tons, 14.1 %
   Miscellaneous weights: 20 tons, 12.9 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     340 lbs / 154 Kg = 107.3 x 1.9 " / 47 mm shells or 0.4 torpedoes
   Stability (Unstable if below 1.00): 1.19
   Metacentric height 0.8 ft / 0.2 m
   Roll period: 11.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 100 %
         - Recoil effect (Restricted arc if above 1.00): 0.03
   Seaboat quality  (Average = 1.00): 1.53

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.500
   Length to Beam Ratio: 6.29 : 1
   'Natural speed' for length: 12.01 kts
   Power going to wave formation at top speed: 41 %
   Trim (Max stability = 0, Max steadiness = 100): 66
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      7.22 ft / 2.20 m
      - Forecastle (20 %):   7.22 ft / 2.20 m
      - Mid (50 %):      7.22 ft / 2.20 m
      - Quarterdeck (15 %):   7.22 ft / 2.20 m
      - Stern:      7.22 ft / 2.20 m
      - Average freeboard:   7.22 ft / 2.20 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 98.1 %
      - Above water (accommodation/working, high = better): 144.6 %
   Waterplane Area: 2,209 Square feet or 205 Square metres
   Displacement factor (Displacement / loading): 151 %
   Structure weight / hull surface area: 25 lbs/sq ft or 121 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.92
      - Longitudinal: 2.15
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is excellent
   Ship has slow, easy roll, a good, steady gun platform
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

[Walter]

Fushimi, Japan Gunboat class 2 laid down 1903

Displacement:
   165 t light; 169 t standard; 183 t normal; 194 t full load

Dimensions: Length overall / water x beam x draught
   160.76 ft / 160.76 ft x 24.28 ft x 3.28 ft (normal load)
   49.00 m / 49.00 m x 7.40 m  x 1.00 m

Armament:
      2 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1903 Model
     Breech loading guns in deck mounts
     on centreline ends, evenly spread
   Weight of broadside 11 lbs / 5 kg
   Shells per gun, main battery: 150

Machinery:
   Coal fired boilers, complex reciprocating steam engines,
   Direct drive, 2 shafts, 342 ihp / 255 Kw = 12.70 kts
   Range 1,000nm at 10.00 kts
   Bunker at max displacement = 25 tons (100% coal)

Complement:
   24 - 32

Cost:
   £0.014 million / $0.056 million

Distribution of weights at normal displacement:
   Armament: 1 tons, 0.8 %
   Machinery: 51 tons, 27.9 %
   Hull, fittings & equipment: 92 tons, 50.3 %
   Fuel, ammunition & stores: 18 tons, 10.0 %
   Miscellaneous weights: 20 tons, 10.9 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     326 lbs / 148 Kg = 57.7 x 2.2 " / 57 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.15
   Metacentric height 0.8 ft / 0.2 m
   Roll period: 11.6 seconds
   Steadiness   - As gun platform (Average = 50 %): 100 %
         - Recoil effect (Restricted arc if above 1.00): 0.04
   Seaboat quality  (Average = 1.00): 1.37

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.500
   Length to Beam Ratio: 6.62 : 1
   'Natural speed' for length: 12.68 kts
   Power going to wave formation at top speed: 40 %
   Trim (Max stability = 0, Max steadiness = 100): 74
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      7.22 ft / 2.20 m
      - Forecastle (20 %):   7.22 ft / 2.20 m
      - Mid (50 %):      7.22 ft / 2.20 m
      - Quarterdeck (15 %):   7.22 ft / 2.20 m
      - Stern:      7.22 ft / 2.20 m
      - Average freeboard:   7.22 ft / 2.20 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 108.7 %
      - Above water (accommodation/working, high = better): 149.0 %
   Waterplane Area: 2,600 Square feet or 242 Square metres
   Displacement factor (Displacement / loading): 137 %
   Structure weight / hull surface area: 27 lbs/sq ft or 130 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.95
      - Longitudinal: 1.82
      - Overall: 1.01
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is excellent
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

[Walter]

Heien, Japan Gunboat class 1 laid down 1883


Displacement:
   1,828 t light; 1,932 t standard; 2,148 t normal; 2,321 t full load

Dimensions: Length overall / water x beam x draught
   199.97 ft / 199.97 ft x 40.03 ft x 13.62 ft (normal load)
   60.95 m / 60.95 m x 12.20 m  x 4.15 m

Armament:
      1 - 10.24" / 260 mm guns in single mounts, 479.97lbs / 217.71kg shells, 1883 Model
     Breech loading gun in Coles/Ericsson turrets
     on centreline ends, evenly spread
      2 - 6.00" / 152 mm guns in single mounts, 96.66lbs / 43.84kg shells, 1883 Model
     Breech loading guns in deck mounts
     on side, all amidships
      8 - 1.85" / 47.0 mm guns (2x4 guns), 2.84lbs / 1.29kg shells, 1883 Model
     Breech loading guns in deck mounts
     on side, evenly spread
   Weight of broadside 696 lbs / 316 kg
   Shells per gun, main battery: 150
   4 - 17.7" / 450 mm submerged torpedo tubes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   7.87" / 200 mm   164.04 ft / 50.00 m   7.58 ft / 2.31 m
   Ends:   Unarmoured
     Main Belt covers 126 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   5.00" / 127 mm   2.36" / 60 mm            -

   - Armour deck: 1.97" / 50 mm, Conning tower: 5.00" / 127 mm

Machinery:
   Coal fired boilers, simple reciprocating steam engines,
   Direct drive, 2 shafts, 636 ihp / 474 Kw = 10.00 kts
   Range 2,500nm at 10.00 kts
   Bunker at max displacement = 389 tons (100% coal)

Complement:
   157 - 205

Cost:
   £0.155 million / $0.619 million

Distribution of weights at normal displacement:
   Armament: 87 tons, 4.0 %
   Armour: 759 tons, 35.3 %
      - Belts: 416 tons, 19.4 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 94 tons, 4.4 %
      - Armour Deck: 232 tons, 10.8 %
      - Conning Tower: 18 tons, 0.8 %
   Machinery: 126 tons, 5.9 %
   Hull, fittings & equipment: 755 tons, 35.1 %
   Fuel, ammunition & stores: 321 tons, 14.9 %
   Miscellaneous weights: 100 tons, 4.7 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     2,761 lbs / 1,252 Kg = 5.8 x 10.2 " / 260 mm shells or 1.0 torpedoes
   Stability (Unstable if below 1.00): 1.12
   Metacentric height 1.6 ft / 0.5 m
   Roll period: 13.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 100 %
         - Recoil effect (Restricted arc if above 1.00): 0.67
   Seaboat quality  (Average = 1.00): 2.00

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.690
   Length to Beam Ratio: 5.00 : 1
   'Natural speed' for length: 14.14 kts
   Power going to wave formation at top speed: 37 %
   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 (% = measuring location as a percentage of overall length):
      - Stem:      10.17 ft / 3.10 m
      - Forecastle (20 %):   10.17 ft / 3.10 m
      - Mid (50 %):      10.17 ft / 3.10 m
      - Quarterdeck (15 %):   10.17 ft / 3.10 m
      - Stern:      10.17 ft / 3.10 m
      - Average freeboard:   10.17 ft / 3.10 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 68.6 %
      - Above water (accommodation/working, high = better): 78.5 %
   Waterplane Area: 6,358 Square feet or 591 Square metres
   Displacement factor (Displacement / loading): 119 %
   Structure weight / hull surface area: 82 lbs/sq ft or 401 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.93
      - Longitudinal: 3.19
      - Overall: 1.05
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is cramped
   Ship has slow, easy roll, a good, steady gun platform
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

[Walter]

Amagi, Japan Gunboat class 2 laid down 1875


Displacement:
   1,080 t light; 1,123 t standard; 1,207 t normal; 1,275 t full load

Dimensions: Length overall / water x beam x draught
   206.69 ft / 206.69 ft x 35.73 ft x 14.30 ft (normal load)
   63.00 m / 63.00 m x 10.89 m  x 4.36 m

Armament:
      1 - 6.69" / 170 mm guns in single mounts, 116.18lbs / 52.70kg shells, 1875 Model
     Breech loading gun in a deck mount with hoist
     on centreline forward
      4 - 4.72" / 120 mm guns in single mounts, 40.86lbs / 18.53kg shells, 1875 Model
     Breech loading guns in deck mounts
     on side, all amidships
      3 - 1.85" / 47.0 mm guns in single mounts, 2.46lbs / 1.11kg shells, 1875 Model
     Breech loading guns in deck mounts
     on side, evenly spread
      12 - 1.00" / 25.4 mm guns (4x3 guns), 0.39lbs / 0.18kg shells, 1875 Model
     Breech loading guns in deck mounts
     on side, evenly spread
   Weight of broadside 292 lbs / 132 kg
   Shells per gun, main battery: 100

Machinery:
   Coal fired boilers, simple reciprocating steam engines,
   Direct drive, 1 shaft, 637 ihp / 475 Kw = 11.00 kts
   Range 1,800nm at 8.00 kts
   Bunker at max displacement = 152 tons (100% coal)

Complement:
   102 - 133

Cost:
   £0.088 million / $0.353 million

Distribution of weights at normal displacement:
   Armament: 36 tons, 3.0 %
   Machinery: 142 tons, 11.8 %
   Hull, fittings & equipment: 752 tons, 62.3 %
   Fuel, ammunition & stores: 127 tons, 10.5 %
   Miscellaneous weights: 150 tons, 12.4 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1,327 lbs / 602 Kg = 11.4 x 6.7 " / 170 mm shells or 0.6 torpedoes
   Stability (Unstable if below 1.00): 1.06
   Metacentric height 1.2 ft / 0.4 m
   Roll period: 13.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 100 %
         - Recoil effect (Restricted arc if above 1.00): 0.39
   Seaboat quality  (Average = 1.00): 2.00

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.400
   Length to Beam Ratio: 5.79 : 1
   'Natural speed' for length: 14.38 kts
   Power going to wave formation at top speed: 31 %
   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 (% = measuring location as a percentage of overall length):
      - Stem:      10.50 ft / 3.20 m
      - Forecastle (20 %):   10.50 ft / 3.20 m
      - Mid (50 %):      10.50 ft / 3.20 m
      - Quarterdeck (15 %):   10.50 ft / 3.20 m
      - Stern:      10.50 ft / 3.20 m
      - Average freeboard:   10.50 ft / 3.20 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 75.1 %
      - Above water (accommodation/working, high = better): 84.3 %
   Waterplane Area: 4,298 Square feet or 399 Square metres
   Displacement factor (Displacement / loading): 166 %
   Structure weight / hull surface area: 101 lbs/sq ft or 495 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 1.26
      - Longitudinal: 5.61
      - Overall: 1.46
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is cramped
   Ship has slow, easy roll, a good, steady gun platform
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

[Walter]

Tsukushi, Japan Gunboat class 1 laid down 1879


Displacement:
   1,117 t light; 1,234 t standard; 1,378 t normal; 1,493 t full load

Dimensions: Length overall / water x beam x draught
   209.97 ft / 209.97 ft x 31.82 ft x 14.44 ft (normal load)
   64.00 m / 64.00 m x 9.70 m  x 4.40 m

Armament:
      2 - 10.00" / 254 mm guns in single mounts, 417.50lbs / 189.37kg shells, 1879 Model
     Breech loading guns in deck mounts with hoists
     on centreline, all aft
      4 - 4.72" / 120 mm guns in single mounts, 44.02lbs / 19.97kg shells, 1879 Model
     Breech loading guns in deck mounts
     on centreline, all amidships
      2 - 2.24" / 57.0 mm guns (1x2 guns), 4.72lbs / 2.14kg shells, 1879 Model
     Breech loading guns in deck mount
     on side
      4 - 1.46" / 37.0 mm guns in single mounts, 1.29lbs / 0.59kg shells, 1879 Model
     Breech loading guns in deck mounts
     on side, evenly spread
   Weight of broadside 1,026 lbs / 465 kg
   Shells per gun, main battery: 150
   2 - 17.7" / 450 mm submerged torpedo tubes

Machinery:
   Coal fired boilers, simple reciprocating steam engines,
   Direct drive, 1 shaft, 1,760 ihp / 1,313 Kw = 14.30 kts
   Range 2,000nm at 10.00 kts
   Bunker at max displacement = 259 tons (100% coal)

Complement:
   113 - 147

Cost:
   £0.189 million / $0.756 million

Distribution of weights at normal displacement:
   Armament: 128 tons, 9.3 %
   Machinery: 302 tons, 21.9 %
   Hull, fittings & equipment: 637 tons, 46.2 %
   Fuel, ammunition & stores: 261 tons, 18.9 %
   Miscellaneous weights: 50 tons, 3.6 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     376 lbs / 171 Kg = 0.9 x 10.0 " / 254 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.23
   Metacentric height 1.3 ft / 0.4 m
   Roll period: 11.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 51 %
         - Recoil effect (Restricted arc if above 1.00): 0.88
   Seaboat quality  (Average = 1.00): 1.15

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.500
   Length to Beam Ratio: 6.60 : 1
   'Natural speed' for length: 14.49 kts
   Power going to wave formation at top speed: 46 %
   Trim (Max stability = 0, Max steadiness = 100): 44
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      6.56 ft / 2.00 m
      - Forecastle (20 %):   6.56 ft / 2.00 m
      - Mid (50 %):      6.56 ft / 2.00 m
      - Quarterdeck (15 %):   6.56 ft / 2.00 m
      - Stern:      6.56 ft / 2.00 m
      - Average freeboard:   6.56 ft / 2.00 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 163.6 %
      - Above water (accommodation/working, high = better): 47.3 %
   Waterplane Area: 4,280 Square feet or 398 Square metres
   Displacement factor (Displacement / loading): 76 %
   Structure weight / hull surface area: 92 lbs/sq ft or 448 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.90
      - Longitudinal: 2.54
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is extremely poor

[Walter]

Banjo, Japan Gunboat class 2 laid down 1877

Displacement:
   526 t light; 553 t standard; 654 t normal; 735 t full load

Dimensions: Length overall / water x beam x draught
   153.87 ft / 153.87 ft x 25.85 ft x 12.80 ft (normal load)
   46.90 m / 46.90 m x 7.88 m  x 3.90 m

Armament:
      1 - 6.00" / 152 mm guns in single mounts, 86.94lbs / 39.44kg shells, 1877 Model
     Breech loading gun in a deck mount with hoist
     on centreline aft
      1 - 4.72" / 120 mm guns in single mounts, 42.44lbs / 19.25kg shells, 1877 Model
     Breech loading gun in deck mount
     on side amidships
      2 - 3.00" / 76.2 mm guns in single mounts, 10.87lbs / 4.93kg shells, 1877 Model
     Breech loading guns in deck mounts
     on side, evenly spread
      12 - 1.00" / 25.4 mm guns (3x4 guns), 0.40lbs / 0.18kg shells, 1877 Model
     Breech loading guns in deck mounts
     on side, evenly spread
   Weight of broadside 156 lbs / 71 kg
   Shells per gun, main battery: 150

Machinery:
   Coal fired boilers, simple reciprocating steam engines,
   Direct drive, 1 shaft, 388 ihp / 289 Kw = 10.50 kts
   Range 2,000nm at 10.00 kts
   Bunker at max displacement = 182 tons (100% coal)

Complement:
   64 - 84

Cost:
   £0.046 million / $0.186 million

Distribution of weights at normal displacement:
   Armament: 19 tons, 3.0 %
   Machinery: 84 tons, 12.8 %
   Hull, fittings & equipment: 392 tons, 60.0 %
   Fuel, ammunition & stores: 129 tons, 19.7 %
   Miscellaneous weights: 30 tons, 4.6 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     783 lbs / 355 Kg = 9.0 x 6.0 " / 152 mm shells or 0.5 torpedoes
   Stability (Unstable if below 1.00): 1.06
   Metacentric height 0.7 ft / 0.2 m
   Roll period: 12.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 100 %
         - Recoil effect (Restricted arc if above 1.00): 0.71
   Seaboat quality  (Average = 1.00): 2.00

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.450
   Length to Beam Ratio: 5.95 : 1
   'Natural speed' for length: 12.40 kts
   Power going to wave formation at top speed: 37 %
   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 (% = measuring location as a percentage of overall length):
      - Stem:      9.84 ft / 3.00 m
      - Forecastle (20 %):   9.84 ft / 3.00 m
      - Mid (50 %):      9.84 ft / 3.00 m
      - Quarterdeck (15 %):   9.84 ft / 3.00 m
      - Stern:      9.84 ft / 3.00 m
      - Average freeboard:   9.84 ft / 3.00 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 70.5 %
      - Above water (accommodation/working, high = better): 70.8 %
   Waterplane Area: 2,418 Square feet or 225 Square metres
   Displacement factor (Displacement / loading): 185 %
   Structure weight / hull surface area: 80 lbs/sq ft or 390 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 1.22
      - Longitudinal: 9.33
      - Overall: 1.49
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is cramped
   Ship has slow, easy roll, a good, steady gun platform
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather