WesWorld

As part of the process of learning how Springsharp works, I've tried to model a historical warship, a Soviet Type 7U destroyer of late 1930s vintage. I am certain I've goofed something in the sim appended below, but I figure the best way to learn is to invite comment.

Please let me know how I could improve.

Project 7A, TBD Destroyer laid down 1938

Displacement:
1,687 t light; 1,747 t standard; 2,039 t normal; 2,272 t full load

Dimensions: Length overall / water x beam x draught
371.64 ft / 361.00 ft x 33.50 ft x 12.50 ft (normal load)
113.28 m / 110.03 m x 10.21 m x 3.81 m

Armament:
4 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.91kg shells, 1938 Model
Dual purpose guns in deck mounts
on centreline ends, evenly spread, all raised mounts - superfiring
4 - 1.57" / 40.0 mm guns in single mounts, 1.95lbs / 0.88kg shells, 1938 Model
Anti-aircraft guns in deck mounts
on centreline, all amidships, all raised mounts - superfiring
12 - 0.79" / 20.0 mm guns (1x12 guns), 0.24lbs / 0.11kg shells, 1938 Model
Anti-aircraft guns in deck mount
on side, all raised guns
Weight of broadside 222 lbs / 100 kg
Shells per gun, main battery: 150
5 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.00" / 25 mm - -

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 50,126 shp / 37,394 Kw = 34.00 kts
Range 4,000nm at 18.00 kts
Bunker at max displacement = 525 tons

Complement:
151 - 197

Cost:
£1.329 million / $5.317 million

Distribution of weights at normal displacement:
Armament: 28 tons, 1.4 %
Armour: 11 tons, 0.5 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 11 tons, 0.5 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 1,097 tons, 53.8 %
Hull, fittings & equipment: 552 tons, 27.1 %
Fuel, ammunition & stores: 352 tons, 17.3 %
Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
512 lbs / 232 Kg = 9.7 x 4.7 " / 120 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.20
Metacentric height 1.4 ft / 0.4 m
Roll period: 12.1 seconds
Steadiness - As gun platform (Average = 50 %): 55 %
- Recoil effect (Restricted arc if above 1.00): 0.18
Seaboat quality (Average = 1.00): 0.55

Hull form characteristics:
Hull has low forecastle, rise aft of midbreak, raised quarterdeck
Block coefficient: 0.472
Length to Beam Ratio: 10.78 : 1
'Natural speed' for length: 19.00 kts
Power going to wave formation at top speed: 69 %
Trim (Max stability = 0, Max steadiness = 100): 100
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 3.00 ft / 0.91 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 21.00 ft / 6.40 m
- Forecastle (10 %): 16.00 ft / 4.88 m (18.00 ft / 5.49 m aft of break)
- Mid (50 %): 8.00 ft / 2.44 m (9.00 ft / 2.74 m aft of break)
- Quarterdeck (15 %): 9.00 ft / 2.74 m (8.00 ft / 2.44 m before break)
- Stern: 8.00 ft / 2.44 m
- Average freeboard: 11.25 ft / 3.43 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 184.1 %
- Above water (accommodation/working, high = better): 77.3 %
Waterplane Area: 7,859 Square feet or 730 Square metres
Displacement factor (Displacement / loading): 68 %
Structure weight / hull surface area: 42 lbs/sq ft or 205 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.68
- Longitudinal: 0.98
- Overall: 0.71
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is cramped
Caution: Lacks seaworthiness - very limited seakeeping ability

Armament - Four 120mm DP in single mounts; Four 40mm Bofors in twin mounts groups abaft funnel; Twelve 20mm Oerlikon in twin mounts.

Three suggestions....

Modify the range from 4,000nm at 18.00 kts to either 4,000nm at 15.00 kts or 2,500nm at 18.00 kts to improve stability.

You'll also need more than the SS default of 150 shells per gun, you'll expend that number of shells rather quickly in a fight. Lets say at 10 rounds per minute firing rate you'll have just 15 minutes worth of ammo.

Finnaly you'll need Misc weight for depth charges, torpedo reloads, radar, sonar ect. but this last bit can wait untill you've familiarized yourself with Springsharp.

Thank you. I didn't even try the miscellaneous weights, as I don't have a clue as to normal ballpark figures.

I am very concerned with the freeboard and breaks in the hull - I'm certain the numbers are off. But I will see what adjusting the bunkers and magazines will accomplish and report back.

I think I am still way off the mark.

Project 7A, TBD Destroyer laid down 1938 (Rev A – Revised Bunkers and Magazines)

Displacement:
1,745 t light; 1,850 t standard; 2,039 t normal; 2,189 t full load

Dimensions: Length overall / water x beam x draught
371.64 ft / 361.00 ft x 33.50 ft x 12.50 ft (normal load)
113.28 m / 110.03 m x 10.21 m x 3.81 m

Armament:
4 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.91kg shells, 1938 Model
Dual purpose guns in deck mounts
on centreline ends, evenly spread, all raised mounts - superfiring
4 - 1.57" / 40.0 mm guns in single mounts, 1.95lbs / 0.88kg shells, 1938 Model
Anti-aircraft guns in deck mounts
on centreline, all amidships, all raised mounts - superfiring
12 - 0.79" / 20.0 mm guns (1x12 guns), 0.24lbs / 0.11kg shells, 1938 Model
Anti-aircraft guns in deck mount
on side, all raised guns
Weight of broadside 222 lbs / 100 kg
Shells per gun, main battery: 500
5 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.00" / 25 mm - -

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 50,126 shp / 37,394 Kw = 34.00 kts
Range 4,000nm at 15.00 kts
Bunker at max displacement = 339 tons

Complement:
151 - 197

Cost:
£1.341 million / $5.364 million

Distribution of weights at normal displacement:
Armament: 28 tons, 1.4 %
Armour: 11 tons, 0.5 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 11 tons, 0.5 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 1,097 tons, 53.8 %
Hull, fittings & equipment: 610 tons, 29.9 %
Fuel, ammunition & stores: 293 tons, 14.4 %
Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
540 lbs / 245 Kg = 10.2 x 4.7 " / 120 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.14
Metacentric height 1.2 ft / 0.4 m
Roll period: 12.6 seconds
Steadiness - As gun platform (Average = 50 %): 54 %
- Recoil effect (Restricted arc if above 1.00): 0.19
Seaboat quality (Average = 1.00): 0.54

Hull form characteristics:
Hull has low forecastle, rise aft of midbreak, raised quarterdeck
Block coefficient: 0.472
Length to Beam Ratio: 10.78 : 1
'Natural speed' for length: 19.00 kts
Power going to wave formation at top speed: 69 %
Trim (Max stability = 0, Max steadiness = 100): 100
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 3.00 ft / 0.91 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 21.00 ft / 6.40 m
- Forecastle (10 %): 16.00 ft / 4.88 m (18.00 ft / 5.49 m aft of break)
- Mid (50 %): 8.00 ft / 2.44 m (9.00 ft / 2.74 m aft of break)
- Quarterdeck (15 %): 9.00 ft / 2.74 m (8.00 ft / 2.44 m before break)
- Stern: 8.00 ft / 2.44 m
- Average freeboard: 11.25 ft / 3.43 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 186.4 %
- Above water (accommodation/working, high = better): 77.3 %
Waterplane Area: 7,859 Square feet or 730 Square metres
Displacement factor (Displacement / loading): 68 %
Structure weight / hull surface area: 46 lbs/sq ft or 227 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.75
- Longitudinal: 1.09
- Overall: 0.78
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is cramped
Caution: Lacks seaworthiness - very limited seakeeping ability

Armament - Four 120mm DP in single mounts; Four 40mm Bofors in twin mounts groups abaft funnel; Twelve 20mm Oerlikon in twin mounts.

Sea boat rating is an issue too....

Springsharp has some problems with small and fast hulls. To learn the "how to" it might be easier to start with some common cruiser design.

However, for a first feeble design I´ve seen worse. ;o)

If you're simming a Type 7U, those had 4x130mm, 2x76.2mm AA, and 3x45mm guns, not 120mm + 40mm.

Indeed, the 7U has a different armament outfit; but I thought taking liberties with the armament outfit was preferable to the hull dimensions. Seems those got skewed too.

Live and learn.

Quoted

Originally posted by HoOmAn
Sea boat rating is an issue too....

Springsharp has some problems with small and fast hulls. To learn the "how to" it might be easier to start with some common cruiser design.

However, for a first feeble design I´ve seen worse. ;o)

Thank you, I'll try that.

BTW, should questions like this be placed here or in the "Non Wesworld" section?

Probably the Non-WW section. I'll just move this thread over there, if you don't mind.

Something else that will help most small vessels like this is a transom stern. You'll find that on the hull page, it's a checkbox right below the dimensions.

You've also got a rather odd deckline with the high stem dropping to the forecastle, then rising and dropping and rising again. Flush deck designs are easier to start out with, IMO.

The seakeeping being terrible is a function of the ship's speed and that you're not using all the strength you have available under WW rules. For a ship of this size and speed, under WW design guidelines (because SS2 has issues in this size range), we allow ships to be legal if they have cross-sectional and overall strengths that are both higher than 0.50.

Additionally, one of the things I found extremely helpful when I was learning Springsharp was to identify a number of what I felt to be the "best" Springsharp designs for a particular type of ship. I'd then set everything up so I got a 100% perfect copy. Then I'd change a few parameters and see how they affected the things I cared about. That gave me insights into how other people designed their own ships and what modifications caused certain sorts of results.

Quoted

Originally posted by Brockpaine
Probably the Non-WW section. I'll just move this thread over there, if you don't mind.

Thank you. I should keep things easier over here.

You have a bunch of hull strength left. I would say that the seakeeping could easily be brought up to 1.00, by increasing the freeboard.

Also, by this point, the 4.7'' guns should be in hoists. Otherwise, the ROF will suffer.

Also, if those 20 mm's are in twin mounts, you should have 6 mounts listed, not just one...just a minor qualm.