In that case I'd be tempted to ship 2x4.5" for surface work and add some more 40mm for AA.
Hows this?
TB-1, Atlantean Torpedo boat laid down 1931
Displacement:
602 t light; 627 t standard; 653 t normal; 674 t full load
Dimensions: Length overall / water x beam x draught
272.64 ft / 263.00 ft x 23.00 ft x 9.00 ft (normal load)
83.10 m / 80.16 m x 7.01 m x 2.74 m
Armament:
2 - 4.50" / 114 mm guns in single mounts, 45.56lbs / 20.67kg shells, 1931 Model
Dual purpose guns in deck mounts
on centreline ends, evenly spread
4 - 1.57" / 39.9 mm guns (2x2 guns), 1.93lbs / 0.88kg shells, 1931 Model
Anti-aircraft guns in deck mounts
on centreline, evenly spread, 1 raised mount
6 - 0.79" / 20.1 mm guns in single mounts, 0.25lbs / 0.11kg shells, 1931 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
4 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1931 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 101 lbs / 46 kg
Shells per gun, main battery: 200
6 - 21.0" / 533.4 mm above water torpedoes
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.79" / 20 mm - -
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 22,000 shp / 16,412 Kw = 33.51 kts
Range 1,000nm at 15.00 kts
Bunker at max displacement = 47 tons
Complement:
63 - 83
Cost:
£0.340 million / $1.361 million
Distribution of weights at normal displacement:
Armament: 13 tons, 1.9 %
Armour: 4 tons, 0.6 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 4 tons, 0.6 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 331 tons, 50.6 %
Hull, fittings & equipment: 235 tons, 35.9 %
Fuel, ammunition & stores: 51 tons, 7.8 %
Miscellaneous weights: 20 tons, 3.1 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
180 lbs / 82 Kg = 3.9 x 4.5 " / 114 mm shells or 0.2 torpedoes
Stability (Unstable if below 1.00): 1.04
Metacentric height 0.6 ft / 0.2 m
Roll period: 12.5 seconds
Steadiness - As gun platform (Average = 50 %): 55 %
- Recoil effect (Restricted arc if above 1.00): 0.34
Seaboat quality (Average = 1.00): 0.87
Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.420
Length to Beam Ratio: 11.43 : 1
'Natural speed' for length: 18.50 kts
Power going to wave formation at top speed: 72 %
Trim (Max stability = 0, Max steadiness = 100): 63
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 2.00 ft / 0.61 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 21.00 ft / 6.40 m
- Forecastle (20 %): 15.75 ft / 4.80 m
- Mid (50 %): 15.75 ft / 4.80 m (7.75 ft / 2.36 m aft of break)
- Quarterdeck (15 %): 7.75 ft / 2.36 m
- Stern: 7.75 ft / 2.36 m
- Average freeboard: 12.17 ft / 3.71 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 182.1 %
- Above water (accommodation/working, high = better): 42.9 %
Waterplane Area: 3,915 Square feet or 364 Square metres
Displacement factor (Displacement / loading): 45 %
Structure weight / hull surface area: 25 lbs/sq ft or 124 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 3.54
- Overall: 0.60
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is extremely poor
Poor seaboat, wet and uncomfortable, reduced performance in heavy weather