WesWorld

...though not quite as small as some of Japan's terrifying designs. I used the RN River class template but changed the date and made her a bit bigger.




FL-01, Italian "Light Frigate" laid down 1922

Displacement:
583 t light; 600 t standard; 632 t normal; 655 t full load
Loading submergence 89 tons/feet

Dimensions:
240.00 ft x 24.00 ft x 9.60 ft (normal load)
73.15 m x 7.32 m x 2.93 m

Armament:
2 - 3.00" / 76 mm guns
3 - 2.24" / 57 mm guns
4 - 0.54" / 14 mm guns
Weight of broadside 44 lbs / 20 kg
4 - 21.0" / 533.4 mm above water torpedoes

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 1 shaft, 29,732 shp / 22,180 Kw = 34.00 kts
Range 3,000nm at 10.00 kts
Caution: Delicate, lightweight machinery

Complement:
63 - 81

Cost:
£0.205 million / $0.822 million

Distribution of weights at normal displacement:
Armament: 6 tons, 0.9 %
Machinery: 359 tons, 56.8 %
Hull, fittings & equipment: 219 tons, 34.6 %
Fuel, ammunition & stores: 49 tons, 7.7 %
Miscellaneous weights: 0 tons, 0.0 %

Metacentric height 0.8

Remarks:
Caution: Hull subject to strain in open-sea
Hull space for machinery, storage & compartmentation is cramped
Room for accommodation & workspaces is cramped

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1.20
Shellfire needed to sink: 171 lbs / 77 Kg = 12.6 x 3.0 " / 76 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 0.2
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 51 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0.15
Relative quality as seaboat: 1.05

Hull form characteristics:
Block coefficient: 0.400
Sharpness coefficient: 0.30
Hull speed coefficient 'M': 8.54
'Natural speed' for length: 15.49 kts
Power going to wave formation at top speed: 75 %
Trim: 48
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 190.0 %
Relative accommodation and working space: 73.7 %
(Average = 100%)
Displacement factor: 31 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 0.47
(Structure weight / hull surface area: 30 lbs / square foot or 145 Kg / square metre)
Relative longitudinal hull strength: 2.99
(for 15.00 ft / 4.57 m average freeboard, freeboard adjustment 6.28 ft)
Relative composite hull strength: 0.57

Looks nice but....

Quoted

Relative cross-sectional hull strength: 0.47

Whoops. I thought that had to be over 0.5.
I don't think it would be too much of a problem to get it above 0.5 though.

What effect does "Caution: Delicate, lightweight machinery" have on a ship? Does that mean that, at full power, pieces of the machinery will start to fly off?

Walter

Like i said, I took the RN River class template. that has a cross-sectional hull strength of ~0.47 as well so it shouldn't be too much of a problem. If it is I'll just reduce speed.

I'm not sure about "delicate lightweight machinery", maybe the turbine will fall out of the hull and give me a huge boost of power because of larger prop?

Adequate range, high speed, and a load of torpedoes. Clearly an offensive menace. But a few tons of misc weight for ASW would make it a lot more versatile.

well, it's a nice TB, but yes, please leave no strength under .5.

I looked at the design myself. If you decrease speed by 1 knot, decrease freeboard by 1 foot and add 20 tons of miscellaneous load, the relative cross-sectional hull strength would be at 0.50.

Walter