My gunboat proposal!
All vital parts are accesible from inside. All mounts are turret mounts.
SpringSharp report:
Proposed gunboat for Drew, Postapocalyptic Finland Gunboat laid down 1920
Displacement:
126 t light; 131 t standard; 136 t normal; 140 t full load
Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(98,43 ft / 98,43 ft) x 19,69 ft x (8,20 / 8,34 ft)
(30,00 m / 30,00 m) x 6,00 m x (2,50 / 2,54 m)
Armament:
2 - 2,99" / 76,0 mm 40,0 cal guns - 12,83lbs / 5,82kg shells, 100 per gun
Quick firing guns in turret on barbette mounts, 1920 Model
1 x Single mount on centreline, forward deck forward
1 x Single mount on centreline, aft deck aft
4 - 1,77" / 45,0 mm 45,0 cal guns - 2,80lbs / 1,27kg shells, 150 per gun
Dual purpose guns in turret on barbette mounts, 1920 Model
4 x Single mounts on sides, aft deck forward
4 - 0,57" / 14,5 mm 50,0 cal guns - 0,11lbs / 0,05kg shells, 150 per gun
Machine guns in deck mounts, 1920 Model
4 x Single mounts on sides, aft deck forward
Weight of broadside 37 lbs / 17 kg
Mines
100 - 110,23 lbs / 50,00 kg mines + 1 reloads - 4,970 t total
in Above water - Stern racks/rails
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0,59" / 15 mm 0,59" / 15 mm 0,39" / 10 mm
2nd: 0,39" / 10 mm 0,39" / 10 mm 0,39" / 10 mm
3rd: 0,20" / 5 mm 0,20" / 5 mm -
- Protected deck - single deck:
For and Aft decks: 0,59" / 15 mm
Forecastle: 0,59" / 15 mm Quarter deck: 0,59" / 15 mm
- Conning towers: Forward 0,98" / 25 mm, Aft 0,98" / 25 mm
Machinery:
Diesel Internal combustion motors,
Geared drive, 1 shaft, 1 269 shp / 947 Kw = 18,00 kts
Range 1 000nm at 10,00 kts
Bunker at max displacement = 9 tons
Complement:
19 - 25
Cost:
£0,031 million / $0,126 million
Distribution of weights at normal displacement:
Armament: 18 tons, 13,2%
- Guns: 12 tons, 8,7%
- Weapons: 6 tons, 4,6%
Armour: 42 tons, 31,2%
- Armament: 30 tons, 21,7%
- Armour Deck: 12 tons, 8,7%
- Conning Towers: 1 tons, 0,8%
Machinery: 37 tons, 27,3%
Hull, fittings & equipment: 28 tons, 20,7%
Fuel, ammunition & stores: 10 tons, 7,6%
Miscellaneous weights: 0 tons, 0,0%
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
66 lbs / 30 Kg = 5,0 x 3,0 " / 76 mm shells or 0,2 torpedoes
Stability (Unstable if below 1.00): 1,00
Metacentric height 0,4 ft / 0,1 m
Roll period: 12,5 seconds
Steadiness - As gun platform (Average = 50 %): 45 %
- Recoil effect (Restricted arc if above 1.00): 0,32
Seaboat quality (Average = 1.00): 0,60
Hull form characteristics:
Hull has a flush deck,
a normal bow and a cruiser stern
Block coefficient (normal/deep): 0,300 / 0,304
Length to Beam Ratio: 5,00 : 1
'Natural speed' for length: 9,92 kts
Power going to wave formation at top speed: 70 %
Trim (Max stability = 0, Max steadiness = 100): 68
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%, 6,56 ft / 2,00 m, 6,56 ft / 2,00 m
- Forward deck: 30,00%, 6,56 ft / 2,00 m, 6,56 ft / 2,00 m
- Aft deck: 35,00%, 6,56 ft / 2,00 m, 6,56 ft / 2,00 m
- Quarter deck: 15,00%, 6,56 ft / 2,00 m, 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): 113,2%
- Above water (accommodation/working, high = better): 70,6%
Waterplane Area: 1 073 Square feet or 100 Square metres
Displacement factor (Displacement / loading): 82%
Structure weight / hull surface area: 18 lbs/sq ft or 90 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,41
- Longitudinal: 3,61
- Overall: 0,50
Caution: Hull subject to strain in open-sea
Cramped machinery, storage, compartmentation space
Cramped accommodation and workspace room
Caution: Lacks seaworthiness - very limited seakeeping ability