WesWorld

2 hull shapes, that work out at the same weight, I'm just not sure which would be best.

Pro's and Con's please, people!!

Hoover (working name!), Denmark Patrol Boat/Minesweeper laid down 1937

Displacement:
187 t light; 195 t standard; 220 t normal; 240 t full load

Dimensions: Length overall / water x beam x draught
130.39 ft / 120.00 ft x 30.00 ft x 5.50 ft (normal load)
39.74 m / 36.58 m x 9.14 m x 1.68 m

Armament:
2 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1937 Model
Dual purpose guns in deck mounts
on centreline ends, evenly spread
4 - 0.79" / 20.0 mm guns (2x2 guns), 0.24lbs / 0.11kg shells, 1937 Model
Dual purpose guns in deck mounts
on side, all amidships, all raised mounts - superfiring
Weight of broadside 12 lbs / 6 kg
Shells per gun, main battery: 500

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.79" / 20 mm 0.79" / 20 mm -
2nd: 0.79" / 20 mm 0.79" / 20 mm -

- Conning tower: 0.79" / 20 mm

Machinery:
Diesel Internal combustion generators,
Electric motors, 1 shaft, 770 shp / 574 Kw = 16.00 kts
Range 3,500nm at 12.00 kts
Bunker at max displacement = 44 tons

Complement:
28 - 37

Cost:
£0.059 million / $0.236 million

Distribution of weights at normal displacement:
Armament: 2 tons, 0.7 %
Armour: 4 tons, 1.9 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 4 tons, 1.6 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 1 tons, 0.3 %
Machinery: 21 tons, 9.7 %
Hull, fittings & equipment: 115 tons, 52.3 %
Fuel, ammunition & stores: 33 tons, 14.9 %
Miscellaneous weights: 45 tons, 20.4 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
833 lbs / 378 Kg = 147.4 x 2.2 " / 57 mm shells or 0.8 torpedoes
Stability (Unstable if below 1.00): 1.09
Metacentric height 1.0 ft / 0.3 m
Roll period: 12.8 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.03
Seaboat quality (Average = 1.00): 1.52

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.389
Length to Beam Ratio: 4.00 : 1
'Natural speed' for length: 13.99 kts
Power going to wave formation at top speed: 66 %
Trim (Max stability = 0, Max steadiness = 100): 47
Bow angle (Positive = bow angles forward): 30.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 18.00 ft / 5.49 m
- Forecastle (20 %): 14.00 ft / 4.27 m
- Mid (50 %): 11.00 ft / 3.35 m
- Quarterdeck (15 %): 11.00 ft / 3.35 m
- Stern: 11.00 ft / 3.35 m
- Average freeboard: 12.37 ft / 3.77 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 61.4 %
- Above water (accommodation/working, high = better): 181.8 %
Waterplane Area: 2,286 Square feet or 212 Square metres
Displacement factor (Displacement / loading): 211 %
Structure weight / hull surface area: 30 lbs/sq ft or 148 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.75
- Longitudinal: 13.33
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

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Hoover 2 (working name again!), Denmark Patrol Boat/Minesweeper laid down 1937

Displacement:
187 t light; 195 t standard; 220 t normal; 240 t full load

Dimensions: Length overall / water x beam x draught
131.55 ft / 120.00 ft x 30.00 ft x 5.50 ft (normal load)
40.10 m / 36.58 m x 9.14 m x 1.68 m

Armament:
2 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1937 Model
Dual purpose guns in deck mounts
on centreline ends, evenly spread
4 - 0.79" / 20.0 mm guns (2x2 guns), 0.24lbs / 0.11kg shells, 1937 Model
Dual purpose guns in deck mounts
on side, all amidships, all raised mounts - superfiring
Weight of broadside 12 lbs / 6 kg
Shells per gun, main battery: 500

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.79" / 20 mm 0.79" / 20 mm -
2nd: 0.79" / 20 mm 0.79" / 20 mm -

- Conning tower: 0.79" / 20 mm

Machinery:
Diesel Internal combustion generators,
Electric motors, 1 shaft, 770 shp / 574 Kw = 16.00 kts
Range 3,500nm at 12.00 kts
Bunker at max displacement = 44 tons

Complement:
28 - 37

Cost:
£0.059 million / $0.236 million

Distribution of weights at normal displacement:
Armament: 2 tons, 0.7 %
Armour: 4 tons, 1.9 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 4 tons, 1.6 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 1 tons, 0.3 %
Machinery: 21 tons, 9.7 %
Hull, fittings & equipment: 115 tons, 52.3 %
Fuel, ammunition & stores: 33 tons, 14.9 %
Miscellaneous weights: 45 tons, 20.4 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
835 lbs / 379 Kg = 147.8 x 2.2 " / 57 mm shells or 0.8 torpedoes
Stability (Unstable if below 1.00): 1.09
Metacentric height 1.0 ft / 0.3 m
Roll period: 12.8 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.03
Seaboat quality (Average = 1.00): 1.50

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.389
Length to Beam Ratio: 4.00 : 1
'Natural speed' for length: 13.99 kts
Power going to wave formation at top speed: 66 %
Trim (Max stability = 0, Max steadiness = 100): 47
Bow angle (Positive = bow angles forward): 30.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 20.00 ft / 6.10 m
- Forecastle (20 %): 16.00 ft / 4.88 m
- Mid (50 %): 16.00 ft / 4.88 m (8.00 ft / 2.44 m aft of break)
- Quarterdeck (15 %): 8.00 ft / 2.44 m
- Stern: 8.00 ft / 2.44 m
- Average freeboard: 12.32 ft / 3.76 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 61.4 %
- Above water (accommodation/working, high = better): 181.8 %
Waterplane Area: 2,286 Square feet or 212 Square metres
Displacement factor (Displacement / loading): 211 %
Structure weight / hull surface area: 31 lbs/sq ft or 149 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.75
- Longitudinal: 13.17
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

I'd go for the one with the raised forecastle as it'll give better seakeeping and leave the aft deck freer for minesweeping gear or boats. If you come to draw it you'll probably have to remove some of the armament on grounds of space.

EXTREMELY small block coefficients, and rather odd shapes (a length to 4:1). If I look at the historical German R-boat (here: http://www.german-navy.de/kriegsmarine/s…rboat/tech.html ), it has a similar maximum speed but a length to beam of around 7:1.

Quoted

Originally posted by Hrolf Hakonson
EXTREMELY small block coefficients, and rather odd shapes (a length to 4:1). If I look at the historical German R-boat (here: http://www.german-navy.de/kriegsmarine/s…rboat/tech.html ), it has a similar maximum speed but a length to beam of around 7:1.

BC more to your liking???
Hoover 2a, Denmark Patrol Boat/Minesweeper laid down 1937

Displacement:
190 t light; 198 t standard; 224 t normal; 245 t full load

Dimensions: Length overall / water x beam x draught
132.70 ft / 120.00 ft x 30.00 ft x 5.00 ft (normal load)
40.45 m / 36.58 m x 9.14 m x 1.52 m

Armament:
2 - 2.24" / 57.0 mm guns in single mounts, 5.65lbs / 2.56kg shells, 1937 Model
Dual purpose guns in deck mounts
on centreline ends, evenly spread
4 - 0.79" / 20.0 mm guns (2x2 guns), 0.24lbs / 0.11kg shells, 1937 Model
Dual purpose guns in deck mounts
on side, all amidships, all raised mounts - superfiring
Weight of broadside 12 lbs / 6 kg
Shells per gun, main battery: 500

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.79" / 20 mm 0.79" / 20 mm -
2nd: 0.79" / 20 mm 0.79" / 20 mm -

- Conning tower: 0.79" / 20 mm

Machinery:
Diesel Internal combustion generators,
Electric motors, 1 shaft, 819 shp / 611 Kw = 16.00 kts
Range 3,500nm at 12.00 kts
Bunker at max displacement = 47 tons

Complement:
28 - 37

Cost:
£0.061 million / $0.242 million

Distribution of weights at normal displacement:
Armament: 2 tons, 0.7 %
Armour: 4 tons, 1.9 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 4 tons, 1.6 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 1 tons, 0.3 %
Machinery: 23 tons, 10.1 %
Hull, fittings & equipment: 121 tons, 54.2 %
Fuel, ammunition & stores: 34 tons, 15.3 %
Miscellaneous weights: 40 tons, 17.9 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
905 lbs / 410 Kg = 160.1 x 2.2 " / 57 mm shells or 0.8 torpedoes
Stability (Unstable if below 1.00): 1.08
Metacentric height 1.0 ft / 0.3 m
Roll period: 12.9 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.03
Seaboat quality (Average = 1.00): 1.50

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.436
Length to Beam Ratio: 4.00 : 1
'Natural speed' for length: 13.84 kts
Power going to wave formation at top speed: 67 %
Trim (Max stability = 0, Max steadiness = 100): 47
Bow angle (Positive = bow angles forward): 30.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 22.00 ft / 6.71 m
- Forecastle (20 %): 18.00 ft / 5.49 m
- Mid (50 %): 16.00 ft / 4.88 m (8.00 ft / 2.44 m aft of break)
- Quarterdeck (15 %): 8.00 ft / 2.44 m
- Stern: 8.00 ft / 2.44 m
- Average freeboard: 13.02 ft / 3.97 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 59.9 %
- Above water (accommodation/working, high = better): 194.9 %
Waterplane Area: 2,357 Square feet or 219 Square metres
Displacement factor (Displacement / loading): 220 %
Structure weight / hull surface area: 30 lbs/sq ft or 147 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.74
- Longitudinal: 15.38
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather



The concept was a vessel that can get into very shallow waters, or over sandbanks easily, so a barge-like hull form (broad and shallow) was considered.