WesWorld

Antisubmarine Gunboat laid down 1941

Displacement: 168 t light; 175 t standard; 200 t normal; 220 t full load

Dimensions: Length overall / water x beam x draught

122.59 ft / 116.47 ft x 18.21 ft x 7.87 ft (normal load) [37.37 m / 35.50 m x 5.55 m x 2.40 m]

Armament:

1 - 3.46" / 88.0 mm guns in single mounts, 20.79lbs / 9.43kg shells, 1936 Model Anti-aircraft gun in deck mount on centreline forward
1 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1930 Model Anti-aircraft gun in deck mount on centreline aft
2 - 0.31" / 8.0 mm guns in single mounts, 0.02lbs / 0.01kg shells, 1934 Model Machineguns in deck mounts on side, evenly spread, all raised mounts
Weight of broadside 21 lbs / 10 kg
Shells per gun, main battery: 300

Machinery:

Diesel Internal combustion motors, Geared drive, 2 shafts, 1,056 shp / 788 Kw = 16.50 kts
Range 2,550nm at 13.00 kts
Bunker at max displacement = 45 tons

Complement: 26 - 34

Cost: £0.074 million / $0.296 million

Distribution of weights at normal displacement:

Armament: 3 tons, 1.3 %
Machinery: 28 tons, 14.0 %
Hull, fittings & equipment: 117 tons, 58.5 %
Fuel, ammunition & stores: 32 tons, 16.2 %
Miscellaneous weights: 20 tons, 10.0 %

Overall survivability and seakeeping ability:

Survivability (Non-critical penetrating hits needed to sink ship): 379 lbs / 172 Kg = 18.2 x 3.5 " / 88 mm shells or 0.5 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 0.5 ft / 0.1 m
Roll period: 11.2 seconds
Steadiness - As gun platform (Average = 50 %): 41 %
- Recoil effect (Restricted arc if above 1.00): 0.12
Seaboat quality (Average = 1.00): 1.03

Hull form characteristics:

Hull has raised forecastle
Block coefficient: 0.419
Length to Beam Ratio: 6.40: 1
'Natural speed' for length: 10.79 kts
Power going to wave formation at top speed: 65 %
Trim (Max stability = 0, Max steadiness = 100): 33
Bow angle (Positive = bow angles forward): 26.00 degrees
Stern overhang: 1.64 ft / 0.50 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 9.19 ft / 2.80 m
- Forecastle (15 %): 8.53 ft / 2.60 m (8.20 ft / 2.50 m aft of break)
- Mid (50 %): 7.55 ft / 2.30 m
- Quarterdeck (25 %): 7.55 ft / 2.30 m
- Stern: 7.55 ft / 2.30 m
- Average freeboard: 7.85 ft / 2.39 m
Ship tends to be wet forward

Ship space, strength and comments:

Space - Hull below water (magazines/engines, low = better): 68.2 %
- Above water (accommodation/working, high = better): 74.9 %
Waterplane Area: 1,321 Square feet or 123 Square metres
Displacement factor (Displacement / loading): 206 %
Structure weight / hull surface area: 43 lbs/sq ft or 209 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.37
- Longitudinal: 11.91
- Overall: 1.71
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is cramped

Wooden hull

Miscellaneous weight = depth charges and handling gear

Hmm. The combination of high superstructure and low freeboard sure give it a bit of an odd look, I must say...

Quoted

Originally posted by Brockpaine
Hmm. The combination of high superstructure and low freeboard sure give it a bit of an odd look, I must say...

I did my best to match the Springsharp with the drawing, which is of a French wooden hulled subchased of the Chasseur 41 class dating to 1939. The hull dimensions are pretty much spot on, and I assumed that the freeboard would be close to the draught.

I personally prefer the lines of the Chasseur 1 class of 1933 - they are far more elegant.

Quoted

Originally posted by BruceDuncan
I personally prefer the lines of the Chasseur 1 class of 1933 - they are far more elegant.

Have any pictures? Not remembering that one...

Quoted

Originally posted by Brockpaine

Quoted

Originally posted by BruceDuncan
I personally prefer the lines of the Chasseur 1 class of 1933 - they are far more elegant.

Have any pictures? Not remembering that one...

You can check here

Excellent site.

Hm, it does indeed look better. Thanks!

Quoted

Originally posted by Brockpaine
Hm, it does indeed look better. Thanks!

I may try my hand at cleaning up a drawing of the Chasseur 1, and see it I can put a Springsharp together for her. Unfortunately, the OTL craft counts as a steel-hulled ship of under 200 tons by our rules, so a SS is rather difficult to craft.

1 - 3.46" / 88.0 mm guns in single mounts, 20.79lbs / 9.43kg shells, 1946 Model Anti-aircraft gun in deck mount on centreline forward

Hmmm

Quoted

Originally posted by Vukovlad
1 - 3.46" / 88.0 mm guns in single mounts, 20.79lbs / 9.43kg shells, 1946 Model Anti-aircraft gun in deck mount on centreline forward

Hmmm

Thank you for calling a small typographical error to my attention.

I'm wondering why you decided to go with the geared drive. If you were going to mass produce these (hypothetically), it might be cheaper just to go with the direct drive, esp. if you're planning to spend most of your time at lower speeds.

The historical vessel, upon which this design is based, used multiple diesel engines to attain the required horsepower. This can be modeled using a geared engine arrangement.

He I just wanted to draw that French one!