WesWorld

Well again my main arguement is cost, and if Britain, the U.S. and others are not doing it yet its not likely a third teir power will do it first. Also, more mounts you can keep your "eggs" in seperate "baskets" so if you have one damaged via splinters in a fight you still have another launcher.

Quoted

Hull strength (Relative):
- Cross-sectional: 0.39

"Back to the old drawing board..."

Hmmm, I thought that was a .50 on the overall was the requirements. I'd thought .50 for the cross-sectional before, but someone said that it was the overall that was the monitor of such things.

It's a 'gentleman's rule' (Gentlemen? Where!?) that if the cross-sectional is below 0.50, you'd better prepare a storyline in which the ship has a structural failure...

Guardia Marina Contrerra

Chilean Light Destroyer laid down 1927

Displacement:
756 t light; 789 t standard; 885 t normal; 959 t full load

Dimensions: Length overall / water x beam x draught
261.76 ft / 250.00 ft x 32.00 ft x 12.00 ft (normal load)
79.79 m / 76.20 m x 9.75 m x 3.66 m

Armament:
2 - 4.33" / 110 mm guns in single mounts, 40.59lbs / 18.41kg shells, 1927 Model
Quick firing guns in deck mounts
on centreline ends, evenly spread
2 - 2.29" / 58.2 mm guns in single mounts, 6.00lbs / 2.72kg shells, 1927 Model
Quick firing guns in deck mounts
on side, evenly spread
2 - 1.46" / 37.0 mm guns (1x2 guns), 1.55lbs / 0.70kg shells, 1927 Model
Anti-aircraft guns in deck mount
on centreline
2 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1927 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
1 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1927 Model
Breech loading gun in deck mount
on centreline, 1 raised gun
Weight of broadside 96 lbs / 44 kg
Shells per gun, main battery: 250
4 - 18.0" / 457.2 mm above water torpedoes

Machinery:
Oil fired boilers, steam turbines,
Direct drive, 2 shafts, 20,000 shp / 14,920 Kw = 31.62 kts
Range 5,500nm at 12.00 kts (Bunkerage = 173 tons)

Complement:
80 - 105

Cost:
£0.358 million / $1.433 million

Distribution of weights at normal displacement:
Armament: 12 tons, 1.4 %
Machinery: 442 tons, 50.0 %
Hull, fittings & equipment: 297 tons, 33.6 %
Fuel, ammunition & stores: 129 tons, 14.5 %
Miscellaneous weights: 5 tons, 0.6 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
325 lbs / 147 Kg = 8.0 x 4.3 " / 110 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.28
Metacentric height 1.4 ft / 0.4 m
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.13
Seaboat quality (Average = 1.00): 1.00

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.323
Length to Beam Ratio: 7.81 : 1
'Natural speed' for length: 18.99 kts
Power going to wave formation at top speed: 71 %
Trim (Max stability = 0, Max steadiness = 100): 70
Bow angle (Positive = bow angles forward): 25.20 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 25.00 ft / 7.62 m
- Forecastle (20 %): 18.00 ft / 5.49 m
- Mid (50 %): 18.00 ft / 5.49 m (9.00 ft / 2.74 m aft of break)
- Quarterdeck (15 %): 9.00 ft / 2.74 m
- Stern: 9.00 ft / 2.74 m
- Average freeboard: 14.06 ft / 4.29 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 173.2 %
- Above water (accommodation/working, high = better): 119.7 %
Waterplane Area: 5,118 Square feet or 475 Square metres
Displacement factor (Displacement / loading): 65 %
Structure weight / hull surface area: 30 lbs/sq ft or 147 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 4.23
- Overall: 0.61
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform

I'd beef up the design a bit to 1000 tons and add another 4.33". Then she could be quite a usefull ship with a decent punch. The older Atlantian Admiralty class DD's have 3x4" and a similar light AA and torpedo outfit, and they are considered too light for todays opponents.

Guardia Marina Contrerra

Chilean Destroyer laid down 1927

Displacement:
811 t light; 850 t standard; 950 t normal; 1,026 t full load

Dimensions: Length overall / water x beam x draught
261.76 ft / 250.00 ft x 32.00 ft x 12.00 ft (normal load)
79.79 m / 76.20 m x 9.75 m x 3.66 m

Armament:
3 - 4.33" / 110 mm guns in single mounts, 40.59lbs / 18.41kg shells, 1927 Model
Quick firing guns in deck mounts
on centreline ends, majority forward, 1 raised mount
2 - 2.29" / 58.2 mm guns in single mounts, 6.00lbs / 2.72kg shells, 1927 Model
Quick firing guns in deck mounts
on side, evenly spread
2 - 1.46" / 37.0 mm guns (1x2 guns), 1.55lbs / 0.70kg shells, 1927 Model
Anti-aircraft guns in deck mount
on centreline
2 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1927 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
1 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1927 Model
Breech loading gun in deck mount
on centreline, 1 raised gun
Weight of broadside 137 lbs / 62 kg
Shells per gun, main battery: 250
4 - 18.0" / 457.2 mm above water torpedoes

Machinery:
Oil fired boilers, steam turbines,
Direct drive, 2 shafts, 21,000 shp / 15,666 Kw = 31.47 kts
Range 5,500nm at 12.00 kts (Bunkerage = 180 tons)

Complement:
85 - 111

Cost:
£0.393 million / $1.571 million

Distribution of weights at normal displacement:
Armament: 17 tons, 1.8 %
Machinery: 466 tons, 49.1 %
Hull, fittings & equipment: 323 tons, 34.0 %
Fuel, ammunition & stores: 139 tons, 14.7 %
Miscellaneous weights: 5 tons, 0.5 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
341 lbs / 155 Kg = 8.4 x 4.3 " / 110 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.25
Metacentric height 1.3 ft / 0.4 m
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.20
Seaboat quality (Average = 1.00): 1.02

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.346
Length to Beam Ratio: 7.81 : 1
'Natural speed' for length: 18.89 kts
Power going to wave formation at top speed: 72 %
Trim (Max stability = 0, Max steadiness = 100): 69
Bow angle (Positive = bow angles forward): 25.20 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 25.00 ft / 7.62 m
- Forecastle (20 %): 19.00 ft / 5.79 m
- Mid (50 %): 18.00 ft / 5.49 m (10.00 ft / 3.05 m aft of break)
- Quarterdeck (15 %): 10.00 ft / 3.05 m
- Stern: 10.00 ft / 3.05 m
- Average freeboard: 14.83 ft / 4.52 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 173.8 %
- Above water (accommodation/working, high = better): 117.5 %
Waterplane Area: 5,042 Square feet or 468 Square metres
Displacement factor (Displacement / loading): 65 %
Structure weight / hull surface area: 31 lbs/sq ft or 152 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 4.87
- Overall: 0.62
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform

That reminds me, we still need Altantian ship data in the encyclopedia.

But then we need a fully functional combat system and news on the Nordmark War as well...so no rush.

Oh don't worry, I'm entirely aware of the enormity of the Atlantian info that is missing, unfortunately the old motherboard took the secret info down to davey jone's locker with it. Needless to say I'll be busy for the coming weeks as my computer seems to be settled down somewhat now.

You can however find some of that info in the infrastructure section on page 2.

Nobody noticed the bc of the last design is 0,346 while the one before was 0,323...? Am I the only one to think that´s a little bit on the low side?

What is low for what is suppose to be a "light" destroyer?

Not so long ago I looked at both the FSS class ships and noticed that I used a BC of 0.38 for them. I thought that that was sligtly on the low side, but no one ever made a remark about that.

Considering the ships these are meant to replace have a bc of under .300....

Well, I talked to Ian about a way to sim pretty small ships (about 40-50 tons) and actually getting a speed of 40 knots without having a hull strength that is too low (seaboat quality was pretty lousy). He told me that various errors occur when using a bc of below 0.30 so one should not use a bc lower than 0.30.

Unfortunately...Chile's early destroyers, with proper mass and dimentions, are around .280.

IIRC, it was said originally that no BC under 0,4 gives acurate results. Ian should these things. If he says it´s 0,3 with his current springsharp version, thatn it´s 0,3 but I´d never go below 0,38 - and that seems already very low. South African TAYGETE-class LDs have a BC of 0,4 on 600ts for example.

But that´s me of course...

The limitation of 0.3 Cb is based on the fact that it is virtually impossible to make a displacement hull with a Cb below this (Source Michael Parsons Article on Parametric design) and this is outside the useful range of many of the formulas used in SpringS*.

I would suggest that going less than 0.4 Cb is fraught with danger and if you allow it, it should limited to small high speed planing or semi-planing hulls.

Ian

www.springsharp.com

That might be but the simple fact is that the old Chilean destroyers are 0.28 using real facts.

I'll work on this other one a little later.

Which Destroyers - can you send or direct me to the SpringS* stats?

Are sure of the stats? -- perhaps the stats seriously understate the real displacement or overstate the draught at that displacement. They could be quoting light, trial or an over-optimisitic design tonnage and then quote max draught including appendages eg not mean hull draught at that displacement but the lowest point of the rudder or screws at maximum draught. Equally the source could be just wrong - eg Conways gets the French Vauquelin class full load displacement wrong - it is 3,410 not 3,140 t.

Ian

www.springsharp.com

The vessel and five similar boats are taken from Jane's Fighting Ships 1924. This hull type is six of the seven old destroyers Chile still has in 1924. Only one (Capitan Thompson) makes any sort of push past 0.3. She is below this one.

Capitan Orella, Chile Destroyer laid down 1897 (Engine 1909)

Displacement:
266 t light; 275 t standard; 311 t normal; 339 t full load

Dimensions: Length overall / water x beam x draught
215.00 ft / 213.00 ft x 21.50 ft x 8.50 ft (normal load)
65.53 m / 64.92 m x 6.55 m x 2.59 m

Armament:
1 - 2.88" / 73.3 mm guns in single mounts, 12.00lbs / 5.44kg shells, 1897 Model
Quick firing gun in deck mount
on centreline forward
5 - 2.29" / 58.2 mm guns in single mounts, 6.00lbs / 2.72kg shells, 1897 Model
Quick firing guns in deck mounts
on side, evenly spread
Weight of broadside 42 lbs / 19 kg
Shells per gun, main battery: 100
2 - 18.0" / 457.2 mm above water torpedoes

Machinery:
Coal fired boilers, complex reciprocating steam engines,
Direct drive, 2 shafts, 4,986 ihp / 3,719 Kw = 25.00 kts
Range 900nm at 15.00 kts (Bunkerage = 66 tons)

Complement:
36 - 48

Cost:
£0.037 million / $0.147 million

Distribution of weights at normal displacement:
Armament: 5 tons, 1.7 %
Machinery: 165 tons, 52.9 %
Hull, fittings & equipment: 91 tons, 29.1 %
Fuel, ammunition & stores: 46 tons, 14.7 %
Miscellaneous weights: 5 tons, 1.6 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
81 lbs / 37 Kg = 6.7 x 2.9 " / 73 mm shells or 0.1 torpedoes
Stability (Unstable if below 1.00): 1.23
Metacentric height 0.7 ft / 0.2 m
Steadiness - As gun platform (Average = 50 %): 100 %
- Recoil effect (Restricted arc if above 1.00): 0.16
Seaboat quality (Average = 1.00): 1.09

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.280
Length to Beam Ratio: 9.91 : 1
'Natural speed' for length: 14.59 kts
Power going to wave formation at top speed: 57 %
Trim (Max stability = 0, Max steadiness = 100): 91
Bow angle (Positive = bow angles forward): 4.30 degrees
Stern overhang: 1.00 ft / 0.30 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 13.25 ft / 4.04 m
- Forecastle (20 %): 9.00 ft / 2.74 m
- Mid (50 %): 6.00 ft / 1.83 m
- Quarterdeck (15 %): 6.00 ft / 1.83 m
- Stern: 6.00 ft / 1.83 m
- Average freeboard: 7.39 ft / 2.25 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 185.1 %
- Above water (accommodation/working, high = better): 85.8 %
Waterplane Area: 3,112 Square feet or 289 Square metres
Displacement factor (Displacement / loading): 38 %
Structure weight / hull surface area: 19 lbs/sq ft or 92 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.34
- Overall: 0.55
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is cramped
Ship has slow, easy roll, a good, steady gun platform

Warning: Block coefficent < 0.3 or > 1.00

------------------------------------------------------------------------

Capitan Thompson, Chile Destroyer laid down 1898 (Engine 1910)

Displacement:
289 t light; 299 t standard; 350 t normal; 389 t full load

Dimensions: Length overall / water x beam x draught
214.00 ft / 213.00 ft x 21.50 ft x 5.33 ft (normal load)
65.23 m / 64.92 m x 6.55 m x 1.62 m

Armament:
1 - 2.88" / 73.3 mm guns in single mounts, 12.00lbs / 5.44kg shells, 1898 Model
Quick firing gun in deck mount
on centreline forward
5 - 2.29" / 58.2 mm guns in single mounts, 6.00lbs / 2.72kg shells, 1898 Model
Quick firing guns in deck mounts
on side, evenly spread
Weight of broadside 42 lbs / 19 kg
Shells per gun, main battery: 100
2 - 18.0" / 457.2 mm above water torpedoes

Machinery:
Coal fired boilers, complex reciprocating steam engines,
Direct drive, 2 shafts, 6,465 ihp / 4,823 Kw = 25.25 kts
Range 1,150nm at 15.00 kts (Bunkerage = 92 tons)

Complement:
39 - 52

Cost:
£0.041 million / $0.162 million

Distribution of weights at normal displacement:
Armament: 5 tons, 1.5 %
Machinery: 186 tons, 53.2 %
Hull, fittings & equipment: 93 tons, 26.5 %
Fuel, ammunition & stores: 61 tons, 17.4 %
Miscellaneous weights: 5 tons, 1.4 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
91 lbs / 41 Kg = 7.6 x 2.9 " / 73 mm shells or 0.1 torpedoes
Stability (Unstable if below 1.00): 1.20
Metacentric height 0.7 ft / 0.2 m
Steadiness - As gun platform (Average = 50 %): 75 %
- Recoil effect (Restricted arc if above 1.00): 0.16
Seaboat quality (Average = 1.00): 0.79

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.502
Length to Beam Ratio: 9.91 : 1
'Natural speed' for length: 14.59 kts
Power going to wave formation at top speed: 67 %
Trim (Max stability = 0, Max steadiness = 100): 95
Bow angle (Positive = bow angles forward): 4.75 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 12.00 ft / 3.66 m
- Forecastle (20 %): 9.00 ft / 2.74 m
- Mid (50 %): 8.00 ft / 2.44 m
- Quarterdeck (15 %): 8.00 ft / 2.44 m
- Stern: 8.00 ft / 2.44 m
- Average freeboard: 8.59 ft / 2.62 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 184.5 %
- Above water (accommodation/working, high = better): 92.0 %
Waterplane Area: 2,939 Square feet or 273 Square metres
Displacement factor (Displacement / loading): 39 %
Structure weight / hull surface area: 18 lbs/sq ft or 88 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.16
- Overall: 0.54
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform
Poor seaboat, wet and uncomfortable, reduced performance in heavy weather