Bharat Gun Boat

[miketr]

A patrol boat to show the Bharat flag up and down the coast.  I will be building a few of these a year for a bit.

Michael

GB-1909, Bharat Gun Boat laid down 1909

Displacement:
   250 t light; 259 t standard; 343 t normal; 411 t full load

Dimensions: Length overall / water x beam x draught
   149.66 ft / 147.64 ft x 22.97 ft x 8.86 ft (normal load)
   45.62 m / 45.00 m x 7.00 m  x 2.70 m

Armament:
      2 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1909 Model
     Breech loading guns in deck mounts
     on centreline ends, evenly spread, 1 raised mount
      4 - 0.49" / 12.5 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1909 Model
     Machine guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 12 lbs / 5 kg
   Shells per gun, main battery: 200

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.98" / 25 mm         -               -
   3rd:   0.39" / 10 mm         -               -

   - Conning tower: 1.97" / 50 mm

Machinery:
   Coal and oil fired boilers, complex reciprocating steam engines,
   Direct drive, 2 shafts, 1,500 ihp / 1,119 Kw = 17.09 kts
   Range 5,540nm at 10.00 kts
   Bunker at max displacement = 152 tons (90% coal)

Complement:
   39 - 51

Cost:
   £0.026 million / $0.104 million

Distribution of weights at normal displacement:
   Armament: 1 tons, 0.4 %
   Armour: 4 tons, 1.3 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 2 tons, 0.7 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 2 tons, 0.6 %
   Machinery: 114 tons, 33.3 %
   Hull, fittings & equipment: 120 tons, 35.1 %
   Fuel, ammunition & stores: 93 tons, 27.0 %
   Miscellaneous weights: 10 tons, 2.9 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     395 lbs / 179 Kg = 69.9 x 2.2 " / 57 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.38
   Metacentric height 1.0 ft / 0.3 m
   Roll period: 9.8 seconds
   Steadiness   - As gun platform (Average = 50 %): 88 %
         - Recoil effect (Restricted arc if above 1.00): 0.04
   Seaboat quality  (Average = 1.00): 1.76

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.400
   Length to Beam Ratio: 6.43 : 1
   'Natural speed' for length: 12.15 kts
   Power going to wave formation at top speed: 60 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 10.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      11.48 ft / 3.50 m
      - Forecastle (20 %):   10.66 ft / 3.25 m
      - Mid (50 %):      9.84 ft / 3.00 m (8.20 ft / 2.50 m aft of break)
      - Quarterdeck (15 %):   8.20 ft / 2.50 m
      - Stern:      8.20 ft / 2.50 m
      - Average freeboard:   9.38 ft / 2.86 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 114.7 %
      - Above water (accommodation/working, high = better): 93.3 %
   Waterplane Area: 2,087 Square feet or 194 Square metres
   Displacement factor (Displacement / loading): 135 %
   Structure weight / hull surface area: 30 lbs/sq ft or 145 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.82
      - Longitudinal: 5.64
      - Overall: 1.00
   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

10 tons for Short Range Radio
1240 nm @ 17 knots

[Korpen]

A patrol boat to show the Bharat flag up and down the coast.  I will be building a few of these a year for a bit.

Armament:
      2 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1909 Model
     Breech loading guns in deck mounts
     on centreline ends, evenly spread, 1 raised mount

I think she needs a larger gun. 57mm guns are pretty useless combat weapons in most situations, it is really insufficient in a gunfight against ships of her own size as well as forcing say  a large merchant ship to stop. If at all possible I would try and fit at least a 10cm gun, it would allow her to be used for a lot more missions such as costal protection, gunnery support or anti-submarine patrol.

[miketr]

GB-1909, Bharat Gun Boat laid down 1909

Displacement:
   249 t light; 259 t standard; 343 t normal; 410 t full load

Dimensions: Length overall / water x beam x draught
   149.52 ft / 147.64 ft x 22.97 ft x 8.86 ft (normal load)
   45.57 m / 45.00 m x 7.00 m  x 2.70 m

Armament:
      1 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1909 Model
     Breech loading gun in deck mount
     on centreline forward, 1 raised gun
      4 - 0.49" / 12.5 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1909 Model
     Machine guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 36 lbs / 16 kg
   Shells per gun, main battery: 150

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.98" / 25 mm         -               -
   3rd:   0.39" / 10 mm         -               -

   - Conning tower: 1.97" / 50 mm

Machinery:
   Coal and oil fired boilers, complex reciprocating steam engines,
   Direct drive, 2 shafts, 1,500 ihp / 1,119 Kw = 17.09 kts
   Range 5,500nm at 10.00 kts
   Bunker at max displacement = 151 tons (90% coal)

Complement:
   39 - 51

Cost:
   £0.028 million / $0.114 million

Distribution of weights at normal displacement:
   Armament: 4 tons, 1.3 %
   Armour: 4 tons, 1.3 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 2 tons, 0.7 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 2 tons, 0.6 %
   Machinery: 114 tons, 33.3 %
   Hull, fittings & equipment: 116 tons, 33.9 %
   Fuel, ammunition & stores: 94 tons, 27.3 %
   Miscellaneous weights: 10 tons, 2.9 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     336 lbs / 153 Kg = 9.5 x 4.1 " / 105 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.44
   Metacentric height 1.0 ft / 0.3 m
   Roll period: 9.5 seconds
   Steadiness   - As gun platform (Average = 50 %): 69 %
         - Recoil effect (Restricted arc if above 1.00): 0.11
   Seaboat quality  (Average = 1.00): 1.38

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.400
   Length to Beam Ratio: 6.43 : 1
   'Natural speed' for length: 12.15 kts
   Power going to wave formation at top speed: 60 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 10.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      10.66 ft / 3.25 m
      - Forecastle (20 %):   9.84 ft / 3.00 m
      - Mid (50 %):      9.84 ft / 3.00 m (6.56 ft / 2.00 m aft of break)
      - Quarterdeck (15 %):   6.56 ft / 2.00 m
      - Stern:      6.56 ft / 2.00 m
      - Average freeboard:   8.27 ft / 2.52 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 121.2 %
      - Above water (accommodation/working, high = better): 82.3 %
   Waterplane Area: 2,087 Square feet or 194 Square metres
   Displacement factor (Displacement / loading): 123 %
   Structure weight / hull surface area: 31 lbs/sq ft or 153 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.85
      - Longitudinal: 4.12
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is cramped
   Good seaboat, rides out heavy weather easily

10 tons for Short Range Radio
1240 nm @ 17 knots

I can fit a single 105mm if I reduce freeboard a bit...

Michael

[Korpen]

GB-1909, Bharat Gun Boat laid down 1909

Displacement:
   249 t light; 259 t standard; 343 t normal; 410 t full load

Dimensions: Length overall / water x beam x draught
   149.52 ft / 147.64 ft x 22.97 ft x 8.86 ft (normal load)
   45.57 m / 45.00 m x 7.00 m  x 2.70 m

Armament:
      1 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1909 Model
     Breech loading gun in deck mount
     on centreline forward, 1 raised gun
 

I can fit a single 105mm if I reduce freeboard a bit...

I think it is a significant improvement. This design is much more capable in auxiliary combat functions. Now she can also be used for gunboat diplomacy in internal maters.

[P3D]

Too deep draught and too fine hull for a 250t slow gunboat. The range is also excessive, IMO.

[Korpen]

Too deep draught and too fine hull for a 250t slow gunboat. The range is also excessive, IMO.

Maybe a bit fine lines, but depth can be intentional to reduce the risk of stamping.

[miketr]

The fine lines was the result of me getting what I wanted and attempting to reduce displacement with one value... the Block coefficient

Perhaps this will be better?

Michael

GB-1909-c, Bharat Gun Boat laid down 1909

Displacement:
   245 t light; 254 t standard; 319 t normal; 371 t full load

Dimensions: Length overall / water x beam x draught
   149.52 ft / 147.64 ft x 22.97 ft x 6.33 ft (normal load)
   45.57 m / 45.00 m x 7.00 m  x 1.93 m

Armament:
      1 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1909 Model
     Breech loading gun in deck mount
     on centreline forward, 1 raised gun
      4 - 0.49" / 12.5 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1909 Model
     Machine guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 36 lbs / 16 kg
   Shells per gun, main battery: 150

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.98" / 25 mm         -               -
   3rd:   0.39" / 10 mm         -               -

   - Conning tower: 1.97" / 50 mm

Machinery:
   Coal and oil fired boilers, complex reciprocating steam engines,
   Direct drive, 2 shafts, 1,500 ihp / 1,119 Kw = 16.99 kts
   Range 4,300nm at 10.00 kts
   Bunker at max displacement = 117 tons (90% coal)

Complement:
   37 - 49

Cost:
   £0.028 million / $0.113 million

Distribution of weights at normal displacement:
   Armament: 4 tons, 1.4 %
   Armour: 4 tons, 1.3 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 2 tons, 0.7 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 2 tons, 0.6 %
   Machinery: 114 tons, 35.8 %
   Hull, fittings & equipment: 112 tons, 35.0 %
   Fuel, ammunition & stores: 74 tons, 23.3 %
   Miscellaneous weights: 10 tons, 3.1 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     304 lbs / 138 Kg = 8.6 x 4.1 " / 105 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.47
   Metacentric height 1.1 ft / 0.3 m
   Roll period: 9.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 56 %
         - Recoil effect (Restricted arc if above 1.00): 0.10
   Seaboat quality  (Average = 1.00): 1.13

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.520
   Length to Beam Ratio: 6.43 : 1
   'Natural speed' for length: 12.15 kts
   Power going to wave formation at top speed: 63 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 10.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      10.66 ft / 3.25 m
      - Forecastle (20 %):   9.84 ft / 3.00 m
      - Mid (50 %):      9.84 ft / 3.00 m (6.56 ft / 2.00 m aft of break)
      - Quarterdeck (15 %):   6.56 ft / 2.00 m
      - Stern:      6.56 ft / 2.00 m
      - Average freeboard:   8.27 ft / 2.52 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 130.2 %
      - Above water (accommodation/working, high = better): 95.7 %
   Waterplane Area: 2,301 Square feet or 214 Square metres
   Displacement factor (Displacement / loading): 115 %
   Structure weight / hull surface area: 30 lbs/sq ft or 147 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.88
      - Longitudinal: 3.13
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is adequate

10 tons for Short Range Radio
930 nm @ 17 knots

[P3D]

What about something like this? The ship would be outclassed by any foreign naval vessel. So a mere gunboat might not be the best option. My suggestion is to slow the ship down 1kts, add another gun, and ~100 more mines + clearing gear besides. There are so few deepwater ports on the shore that mines combined with coastal artillery should be a viable and cost-effective defense.

You could minimalize the design a bit further. 2000nm range, 15kts speed and 80-90 mines on ~333t light.


Bharat Mine vessel laid down 1909

Displacement:
   400 t light; 421 t standard; 487 t normal; 540 t full load

Dimensions: Length overall / water x beam x draught
   160.00 ft / 160.00 ft x 22.00 ft x 6.00 ft (normal load)
   48.77 m / 48.77 m x 6.71 m  x 1.83 m

Armament:
      2 - 4.10" / 105 mm guns in single mounts, 34.46lbs / 15.63kg shells, 1909 Model
     Breech loading guns in deck mounts
     on centreline ends, evenly spread
      4 - 0.49" / 12.5 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1909 Model
     Machine guns in deck mounts
     on side, all amidships
   Weight of broadside 69 lbs / 31 kg
   Shells per gun, main battery: 300

Machinery:
   Coal fired boilers, complex reciprocating steam engines,
   Direct drive, 1 shaft, 1,650 ihp / 1,231 Kw = 16.00 kts
   Range 3,000nm at 10.00 kts
   Bunker at max displacement = 118 tons (100% coal)

Complement:
   51 - 67

Cost:
   £0.039 million / $0.156 million

Distribution of weights at normal displacement:
   Armament: 9 tons, 1.8 %
   Machinery: 127 tons, 26.1 %
   Hull, fittings & equipment: 149 tons, 30.6 %
   Fuel, ammunition & stores: 87 tons, 17.9 %
   Miscellaneous weights: 115 tons, 23.6 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     436 lbs / 198 Kg = 12.6 x 4.1 " / 104 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.13
   Metacentric height 0.6 ft / 0.2 m
   Roll period: 11.5 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.24
   Seaboat quality  (Average = 1.00): 1.38

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.807
   Length to Beam Ratio: 7.27 : 1
   'Natural speed' for length: 12.65 kts
   Power going to wave formation at top speed: 62 %
   Trim (Max stability = 0, Max steadiness = 100): 51
   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:      14.00 ft / 4.27 m
      - Forecastle (20 %):   9.00 ft / 2.74 m
      - Mid (50 %):      9.00 ft / 2.74 m
      - Quarterdeck (15 %):   9.00 ft / 2.74 m
      - Stern:      9.00 ft / 2.74 m
      - Average freeboard:   9.40 ft / 2.87 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 125.1 %
      - Above water (accommodation/working, high = better): 104.8 %
   Waterplane Area: 3,117 Square feet or 290 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: 0.87
      - Longitudinal: 3.31
      - Overall: 1.00
   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
   Good seaboat, rides out heavy weather easily

[miketr]

I was going to build a mine layer for them at some point...  Script sorta requires it so it seams...

That said their tech sucks and little hope I can do much about it right away. 

Also the mission of a GB isn't to stand up to foreign warship which it would have no chance but to show the flag and ride heard on fat and dumb merchantmen.  I will consider the design though...

Michael