WesWorld

First attempt at a sub! What do you think?



D Class(A), Denmark Fleet Submarine laid down 1924

Displacement:
1,230 t light; 1,264 t standard; 1,539 t normal; 1,753 t full load
Loading submergence 100 tons/feet

Dimensions:
250.00 ft x 34.00 ft x 24.00 ft (normal load)
76.20 m x 10.36 m x 7.32 m

Armament:
1 - 3.94" / 100 mm guns
2 - 0.79" / 20 mm AA guns
2 - 0.51" / 13 mm guns
Weight of broadside 31 lbs / 14 kg
8 - 21.0" / 533.4 mm submerged torpedo tubes

Machinery:
Diesel Internal combustion engines plus batteries,
Electric cruising motors plus geared drives, 2 shafts, 3,146 shp / 2,347 Kw = 17.00 kts
Range 9,000nm at 12.00 kts

Complement:
122 - 159

Cost:
£0.188 million / $0.752 million

Distribution of weights at normal displacement:
Armament: 4 tons, 0.3 %
Machinery: 104 tons, 6.7 %
Hull, fittings & equipment: 843 tons, 54.8 %
Fuel, ammunition & stores: 309 tons, 20.0 %
Miscellaneous weights: 280 tons, 18.2 %

Metacentric height 1.1

Remarks:
Hull space for machinery, storage & compartmentation is excellent
Room for accommodation & workspaces is extremely poor

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1.06
Shellfire needed to sink: 1,076 lbs / 488 Kg = 35.3 x 3.9 " / 100 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 0.5
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 1 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0.00
Relative quality as seaboat: 0.00

Hull form characteristics:
Block coefficient: 0.264
Sharpness coefficient: 0.27
Hull speed coefficient 'M': 6.62
'Natural speed' for length: 15.81 kts
Power going to wave formation at top speed: 35 %
Trim: 50
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 74.2 %
Relative accommodation and working space: 0.5 %
(Average = 100%)
Displacement factor: 297 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 2.38
(Structure weight / hull surface area: 118 lbs / square foot or 577 Kg / square metre)
Relative longitudinal hull strength: 4.31
(for 0.10 ft / 0.03 m average freeboard, freeboard adjustment -10.31 ft)
Relative composite hull strength: 2.52

Diving Depth = 252'
Emergency Depth = 403'
Crush Depth = 630'

The top view of the drawing dosen't match up with the block coefficient. What you draw seems to have a BC of about 0.6, but the specification shows 0.264. It would be tough to fit everything into a sub with a BC that low.

I was trying to get the BC to stay up at something I thought of as reasonable (.45 or more), but every time I added weight or lenght, it went down......what am I doing wrong?

Update, by maxing out on the weight, I can get it up to .403 BC........again I ask, what am I doing wrong????

Maxxed out .................

D Class(B), Denmark Fleet Submarine laid down 1924

Displacement:
1,935 t light; 1,985 t standard; 2,349 t normal; 2,631 t full load
Loading submergence 132 tons/feet

Dimensions:
250.00 ft x 34.00 ft x 24.00 ft (normal load)
76.20 m x 10.36 m x 7.32 m

Armament:
1 - 3.94" / 100 mm guns
2 - 0.79" / 20 mm AA guns
2 - 0.51" / 13 mm guns
Weight of broadside 31 lbs / 14 kg
8 - 21.0" / 533.4 mm submerged torpedo tubes

Armour:
AA gun shields 0.50" / 13 mm

Machinery:
Diesel Internal combustion engines plus batteries,
Electric cruising motors plus geared drives, 2 shafts, 7,602 shp / 5,671 Kw = 20.00 kts
Range 10,000nm at 12.00 kts

Complement:
168 - 219

Cost:
£0.328 million / $1.311 million

Distribution of weights at normal displacement:
Armament: 4 tons, 0.2 %
Armour: 0 tons, 0.0 %
Belts: 0 tons, 0.0 %, Armament: 0 tons, 0.0 %, Armour Deck: 0 tons, 0.0 %
Conning Tower: 0 tons, 0.0 %, Torpedo bulkhead: 0 tons, 0.0 %
Machinery: 250 tons, 10.7 %
Hull, fittings & equipment: 1,401 tons, 59.6 %
Fuel, ammunition & stores: 414 tons, 17.6 %
Miscellaneous weights: 280 tons, 11.9 %

Metacentric height 1.4

Remarks:
Hull space for machinery, storage & compartmentation is excellent
Room for accommodation & workspaces is extremely poor
Ship has quick, lively roll, not a steady gun platform
Caution: Lacks seaworthiness - very limited seakeeping ability

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1.22
Shellfire needed to sink: 1,577 lbs / 715 Kg = 51.7 x 3.9 " / 100 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 0.5
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 1 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0.00
Relative quality as seaboat: 0.00

Hull form characteristics:
Block coefficient: 0.403
Sharpness coefficient: 0.33
Hull speed coefficient 'M': 5.75
'Natural speed' for length: 15.81 kts
Power going to wave formation at top speed: 53 %
Trim: 50
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 82.8 %
Relative accommodation and working space: 0.5 %
(Average = 100%)
Displacement factor: 289 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 3.44
(Structure weight / hull surface area: 171 lbs / square foot or 837 Kg / square metre)
Relative longitudinal hull strength: 4.70
(for 0.10 ft / 0.03 m average freeboard, freeboard adjustment -11.23 ft)
Relative composite hull strength: 3.55

Diving Depth = 355'
Emergency Depth = 568'
Crush Depth = 887.5'

More the size of your original design. I just entered a BC of 0.500, and varied the other hull dimensions:

UD-1B, Danish fleet Submarine laid down 1924

Displacement:
1,264 t light; 1,299 t standard; 1,587 t normal; 1,810 t full load
Loading submergence 110 tons/feet

Dimensions:
226.00 ft x 27.00 ft x 18.20 ft (normal load)
68.88 m x 8.23 m x 5.55 m

Armament:
1 - 3.94" / 100 mm guns
2 - 0.79" / 20 mm guns
2 - 0.51" / 13 mm AA guns
Weight of broadside 31 lbs / 14 kg
8 - 21.0" / 533.4 mm submerged torpedo tubes

Machinery:
Diesel Internal combustion generators plus batteries,
Electric motors, 2 shafts, 4,117 shp / 3,071 Kw = 18.00 kts
Range 10,000nm at 12.00 kts

Complement:
125 - 163

Cost:
£0.206 million / $0.822 million

Distribution of weights at normal displacement:
Armament: 4 tons, 0.2 %
Machinery: 136 tons, 8.5 %
Hull, fittings & equipment: 845 tons, 53.3 %
Fuel, ammunition & stores: 322 tons, 20.3 %
Miscellaneous weights: 280 tons, 17.6 %

Metacentric height 0.8

Remarks:
Hull space for machinery, storage & compartmentation is cramped
Room for accommodation & workspaces is extremely poor
Ship has quick, lively roll, not a steady gun platform
Caution: Lacks seaworthiness - very limited seakeeping ability

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1.09
Shellfire needed to sink: 668 lbs / 303 Kg = 21.9 x 3.9 " / 100 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: 0 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0.00
Relative quality as seaboat: 0.00

Hull form characteristics:
Block coefficient: 0.500
Sharpness coefficient: 0.35
Hull speed coefficient 'M': 5.92
'Natural speed' for length: 15.03 kts
Power going to wave formation at top speed: 53 %
Trim: 50
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 111.3 %
Relative accommodation and working space: 0.0 %
(Average = 100%)
Displacement factor: 272 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 3.53
(Structure weight / hull surface area: 136 lbs / square foot or 666 Kg / square metre)
Relative longitudinal hull strength: 2.92
(for 0.00 ft / 0.00 m average freeboard, freeboard adjustment -10.48 ft)
Relative composite hull strength: 3.06

Thanks, seems to be the sort of thing I was aimimg for originally, I was using the data for H.M.S. Oberon, which was laid down in 1925, but as you see it didn't work out!!

After a while on the Atkin's Diet................

A little weaker, but back to the size I initially wanted!



D Class (C), Denmark Fleet submarine laid down 1924

Displacement:
1,187 t light; 1,218 t standard; 1,429 t normal; 1,591 t full load
Loading submergence 112 tons/feet

Dimensions:
250.00 ft x 25.00 ft x 16.00 ft (normal load)
76.20 m x 7.62 m x 4.88 m

Armament:
1 - 3.94" / 100 mm guns
2 - 0.79" / 20 mm AA guns
2 - 0.49" / 13 mm guns
Weight of broadside 31 lbs / 14 kg
8 - 21.0" / 533.4 mm submerged torpedo tubes

Machinery:
Diesel Internal combustion generators plus batteries,
Electric motors, 2 shafts, 5,513 shp / 4,113 Kw = 20.00 kts
Range 8,000nm at 12.00 kts

Complement:
116 - 151

Cost:
£0.217 million / $0.868 million

Distribution of weights at normal displacement:
Armament: 4 tons, 0.3 %
Machinery: 182 tons, 12.7 %
Hull, fittings & equipment: 701 tons, 49.1 %
Fuel, ammunition & stores: 242 tons, 16.9 %
Miscellaneous weights: 300 tons, 21.0 %

Metacentric height 0.6

Remarks:
Hull space for machinery, storage & compartmentation is cramped
Room for accommodation & workspaces is extremely poor
Ship has quick, lively roll, not a steady gun platform
Caution: Lacks seaworthiness - very limited seakeeping ability

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1.01
Shellfire needed to sink: 343 lbs / 156 Kg = 11.2 x 3.9 " / 100 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 0.1
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 1 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0.00
Relative quality as seaboat: 0.00

Hull form characteristics:
Block coefficient: 0.500
Sharpness coefficient: 0.33
Hull speed coefficient 'M': 6.78
'Natural speed' for length: 15.81 kts
Power going to wave formation at top speed: 53 %
Trim: 50
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 145.1 %
Relative accommodation and working space: 0.6 %
(Average = 100%)
Displacement factor: 206 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 3.19
(Structure weight / hull surface area: 113 lbs / square foot or 552 Kg / square metre)
Relative longitudinal hull strength: 1.72
(for 0.10 ft / 0.03 m average freeboard, freeboard adjustment -10.16 ft)
Relative composite hull strength: 2.00

Operating Depth = 200'
Emergency Depth = 320'
Crush Depth = 500'