Confederate Coastal Gunboat

[Carthaginian]

Designed to patrol the coastal areas of the Confederacy, these little ships are not the most weatherly in the world, but they are capable of inflicting a nasty surprise on any pirate that chooses to operate near the Confederacy. The 12" guns will be taken from the Nevada-class battleships when they are disposed of next year.

I might work on the design a bit more, giving it enough freeboard to be weatherly enough to serve as a convoy escort. :)



Santa Bouge, Confederate States of America Riverine Gunboat laid down 1910 (Engine 1909)
Barbette ship

Displacement:
   2,000 t light; 2,092 t standard; 2,230 t normal; 2,340 t full load

Dimensions: Length overall / water x beam x draught
   250.00 ft / 250.00 ft x 50.00 ft x 8.50 ft (normal load)
   76.20 m / 76.20 m x 15.24 m  x 2.59 m

Armament:
      2 - 12.00" / 305 mm guns in single mounts, 850.00lbs / 385.55kg shells, 1910 Model
     Breech loading guns in open barbettes
     on centreline ends, evenly spread
      6 - 4.00" / 102 mm guns in single mounts, 25.00lbs / 11.34kg shells, 1910 Model
     Quick firing guns in deck mounts with hoists
     on side, evenly spread, 2 raised mounts
      4 - 1.00" / 25.4 mm guns in single mounts, 0.50lbs / 0.23kg shells, 1910 Model
     Machine guns in deck mounts
     on side ends, evenly spread, all raised mounts - superfiring
      1 - 4.00" / 102 mm guns in single mounts, 25.00lbs / 11.34kg shells, 1910 Model
     Anti-aircraft gun in deck mount
     on centreline amidships, 1 raised gun
   Weight of broadside 1,877 lbs / 851 kg
   Shells per gun, main battery: 45

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   3.00" / 76 mm   164.00 ft / 49.99 m   11.00 ft / 3.35 m
   Ends:   Unarmoured
     Main Belt covers 101 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:         -            -         3.00" / 76 mm
   2nd:   1.00" / 25 mm         -         2.00" / 51 mm
   3rd:   0.50" / 13 mm         -               -
   4th:   0.50" / 13 mm         -               -

   - Armour deck: 1.00" / 25 mm, Conning tower: 3.00" / 76 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 2,400 shp / 1,790 Kw = 14.28 kts
   Range 2,800nm at 10.58 kts
   Bunker at max displacement = 248 tons

Complement:
   161 - 210

Cost:
   £0.289 million / $1.155 million

Distribution of weights at normal displacement:
   Armament: 244 tons, 11.0 %
   Armour: 534 tons, 23.9 %
      - Belts: 246 tons, 11.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 86 tons, 3.8 %
      - Armour Deck: 191 tons, 8.6 %
      - Conning Tower: 11 tons, 0.5 %
   Machinery: 97 tons, 4.4 %
   Hull, fittings & equipment: 1,098 tons, 49.2 %
   Fuel, ammunition & stores: 230 tons, 10.3 %
   Miscellaneous weights: 26 tons, 1.2 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     3,215 lbs / 1,458 Kg = 3.7 x 12.0 " / 305 mm shells or 1.0 torpedoes
   Stability (Unstable if below 1.00): 1.39
   Metacentric height 3.1 ft / 1.0 m
   Roll period: 11.8 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.44
   Seaboat quality  (Average = 1.00): 1.29

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.735
   Length to Beam Ratio: 5.00 : 1
   'Natural speed' for length: 15.81 kts
   Power going to wave formation at top speed: 46 %
   Trim (Max stability = 0, Max steadiness = 100): 55
   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:      12.00 ft / 3.66 m
      - Forecastle (20 %):   12.00 ft / 3.66 m
      - Mid (50 %):      12.00 ft / 3.66 m (8.00 ft / 2.44 m aft of break)
      - Quarterdeck (15 %):   8.00 ft / 2.44 m
      - Stern:      9.00 ft / 2.74 m
      - Average freeboard:   10.08 ft / 3.07 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 94.2 %
      - Above water (accommodation/working, high = better): 120.3 %
   Waterplane Area: 10,330 Square feet or 960 Square metres
   Displacement factor (Displacement / loading): 82 %
   Structure weight / hull surface area: 87 lbs/sq ft or 427 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.92
      - Longitudinal: 2.03
      - 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
   Good seaboat, rides out heavy weather easily

1" splinter shields for 12" guns included in Misc. Weight (16 tons).

[swamphen]

OK, now THAT is like totally rad, dude.  :thumbsup:

[Desertfox]

A lot like a bigger version of my 8" Gunboat, and like my own planned 12" Fisher Follie.

[Carthaginian]

OK, now THAT is like totally rad, dude.  :thumbsup:

Thanks, man.
Gotta have something to do with those guns when I get rid of my old BB's... and they are too short-ranged for good coastal artillery. However, if I were to mount them on some small, somewhat armored ships with shallow drafts, I could use them in a great number of tight spots where heavy guns would be greatly appreciated. Shoot, I could get these bad boys up to the head of navigation of every river in the Western hemisphere... THAT is some very mobile firepower.

Also, they are pretty low in the water, but they could be used as escorts should I want to run any convoys in my coastal waters... imagine seeing THIS coming at you if you're a sub skipper!

[swamphen]

imagine seeing THIS coming at you if you're a sub skipper!

Better put a ram bow on her then.  ;D

[Carthaginian]

NO! Ships with ram bows are TKing biatches! ;)

[Borys]

Ahoj!
A nice bathtub :)
SS seriously understimates the gun weights, I think.
90 tons for the 12 inchers alone. But as these ships won't tip the balance of power, leddem be ....

A question to the more knowledgable - should these ships be "barbette" at all?
Is the hull deep enough for that? Maybe "mount&hoist"?

Not sure of the convoy duty - those oldies can fire once per 90-120 seconds. A newer cruiser would simply smother it with fire. But a faint hearted captain, on seeing the size of the splash, would turn away ...

Borys

[Carthaginian]

I'll sim it in SS3 later today since it does a better job on such things.
If it says i can do it, I might build me 4 of them. Mostly, they are mobile artillery platforms. I know that they'd make lousy escorts, and my attempts at making them more seaworthy than they are isn't going anywhere.

[Carthaginian]

Actually, SS2 is not too generous- it's too cruel.
Here's what SS3's better programing will let me do.

Better deck and barbette armor, lower speed (by a couple hundredths) and overall no real changes:

Enter ship name, Enter country Enter ship type laid down 1910 (Engine 1909)
Barbette ship

Displacement:
   2,000 t light; 2,116 t standard; 2,254 t normal; 2,364 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (250.00 ft / 250.00 ft) x 50.00 ft x (8.50 / 8.87 ft)
   (76.20 m / 76.20 m) x 15.24 m  x (2.59 / 2.70 m)

Armament:
      2 - 12.00" / 305 mm 35.0 cal guns - 850.00lbs / 385.55kg shells, 45 per gun
     Breech loading guns in open barbette mounts, 1893 Model
     2 x Single mounts on centreline ends, evenly spread
      6 - 4.00" / 102 mm 45.0 cal guns - 25.00lbs / 11.34kg shells, 300 per gun
     Breech loading guns in deck and hoist mounts, 1910 Model
     6 x Single mounts on sides amidships
      4 - 1.00" / 25.4 mm 45.0 cal guns - 0.50lbs / 0.23kg shells, 500 per gun
     Machine guns in deck mounts, 1910 Model
     4 x Single mounts on sides amidships
      4 raised mounts
      1 - 4.00" / 102 mm 45.0 cal gun - 32.27lbs / 14.64kg shells, 150 per gun
     Anti-air gun in deck mount, 1910 Model
     1 x Single mount on sides amidships
      Weight of broadside 1,884 lbs / 855 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   4.00" / 102 mm   180.00 ft / 54.86 m   11.00 ft / 3.35 m
   Ends:   Unarmoured
     Main Belt covers 111 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:         -            -         4.00" / 102 mm
   2nd:   1.00" / 25 mm         -         2.00" / 51 mm
   3rd:   0.50" / 13 mm         -               -
   4th:   0.50" / 13 mm         -               -

   - Armoured deck - multiple decks: 1.00" / 25 mm For and Aft decks
   Forecastle: 1.00" / 25 mm  Quarter deck: 1.00" / 25 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 2,399 shp / 1,790 Kw = 14.24 kts
   Range 2,800nm at 10.56 kts
   Bunker at max displacement = 248 tons

Complement:
   163 - 212

Cost:
   £0.188 million / $0.752 million

Distribution of weights at normal displacement:
   Armament: 326 tons, 14.5 %
   Armour: 665 tons, 29.5 %
      - Belts: 359 tons, 15.9 %
      - Armament: 112 tons, 5.0 %
      - Armour Deck: 194 tons, 8.6 %
   Machinery: 109 tons, 4.8 %
   Hull, fittings & equipment: 874 tons, 38.8 %
   Fuel, ammunition & stores: 254 tons, 11.3 %
   Miscellaneous weights: 26 tons, 1.2 %
      - Hull below water: 10 tons
      - On freeboard deck: 16 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     5,617 lbs / 2,548 Kg = 6.5 x 12.0 " / 305 mm shells or 1.8 torpedoes
   Stability (Unstable if below 1.00): 1.60
   Metacentric height 3.9 ft / 1.2 m
   Roll period: 10.6 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.38
   Seaboat quality  (Average = 1.00): 1.39

Hull form characteristics:
   Hull has rise forward of midbreak,
     a normal bow and a round stern
   Block coefficient (normal/deep): 0.742 / 0.746
   Length to Beam Ratio: 5.00 : 1
   'Natural speed' for length: 15.81 kts
   Power going to wave formation at top speed: 46 %
   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 (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  14.00 ft / 4.27 m,  12.00 ft / 3.66 m
      - Forward deck:   30.00 %,  12.00 ft / 3.66 m,  12.00 ft / 3.66 m
      - Aft deck:   35.00 %,  8.00 ft / 2.44 m,  8.00 ft / 2.44 m
      - Quarter deck:   15.00 %,  8.00 ft / 2.44 m,  9.00 ft / 2.74 m
      - Average freeboard:      10.24 ft / 3.12 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 58.4 %
      - Above water (accommodation/working, high = better): 119.7 %
   Waterplane Area: 10,401 Square feet or 966 Square metres
   Displacement factor (Displacement / loading): 119 %
   Structure weight / hull surface area: 85 lbs/sq ft or 415 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.92
      - Longitudinal: 2.15
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is adequate
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily