WesWorld

This is what I have being paying with to get a 36 knots destroyer to accompany the Heavy destroyers in the late 1930's. The protection came down to almost nothing and that is a concern. My question is if I will be better served by continue to build the Capitan Valdes well into the late 1930's? The only advantage this ship have over the Valdes is speed and in the down side the protection is pitiful. Feel free to dissect.

Terror, Peru Destroyer laid down 1938

Displacement:
1,765 t light; 1,843 t standard; 2,099 t normal; 2,303 t full load

Dimensions: Length overall / water x beam x draught
396.00 ft / 396.00 ft x 36.60 ft x 14.00 ft (normal load)
120.70 m / 120.70 m x 11.16 m x 4.27 m

Armament:
4 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1938 Model
Breech loading guns in deck mounts with hoists
on centreline, evenly spread, 2 raised mounts
Aft Main mounts separated by engine room
4 - 1.46" / 37.0 mm guns in single mounts, 1.55lbs / 0.70kg shells, 1938 Model
Anti-aircraft guns in deck mounts
on side ends, evenly spread
8 - 0.98" / 25.0 mm guns (4x2 guns), 0.48lbs / 0.22kg shells, 1938 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 422 lbs / 191 kg
Shells per gun, main battery: 150
8 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.79" / 20 mm - -
2nd: 0.39" / 10 mm - -
3rd: 0.39" / 10 mm - -

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 48,082 shp / 35,869 Kw = 36.00 kts
Range 5,700nm at 15.00 kts
Bunker at max displacement = 460 tons

Complement:
154 - 201

Cost:
£1.428 million / $5.714 million

Distribution of weights at normal displacement:
Armament: 53 tons, 2.5 %
Armour: 12 tons, 0.6 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 12 tons, 0.6 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 1,052 tons, 50.2 %
Hull, fittings & equipment: 628 tons, 29.9 %
Fuel, ammunition & stores: 333 tons, 15.9 %
Miscellaneous weights: 20 tons, 1.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
514 lbs / 233 Kg = 5.0 x 5.9 " / 150 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.37
Metacentric height 1.9 ft / 0.6 m
Roll period: 11.1 seconds
Steadiness - As gun platform (Average = 50 %): 54 %
- Recoil effect (Restricted arc if above 1.00): 0.51
Seaboat quality (Average = 1.00): 1.09

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.362
Length to Beam Ratio: 10.82 : 1
'Natural speed' for length: 23.01 kts
Power going to wave formation at top speed: 65 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 0.00 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 (25 %): 21.00 ft / 6.40 m
- Mid (40 %): 20.00 ft / 6.10 m (12.00 ft / 3.66 m aft of break)
- Quarterdeck (15 %): 12.00 ft / 3.66 m
- Stern: 12.00 ft / 3.66 m
- Average freeboard: 15.93 ft / 4.85 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 182.1 %
- Above water (accommodation/working, high = better): 98.8 %
Waterplane Area: 9,126 Square feet or 848 Square metres
Displacement factor (Displacement / loading): 68 %
Structure weight / hull surface area: 35 lbs/sq ft or 171 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.44
- Longitudinal: 1.74
- Overall: 0.50
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate

20 tons reserved for growth

On smaller ships like this, the cross-sectional strength has to stay above 0.50. You could get some strength back by reducing the range a bit. Also, this ship has no heavy AA at all, which is possibly questionable.

Ditto Hrolf. Throw on a battery of, say, four 88mm AA guns. The protection doesn't matter so much for a ship of this size and speed.

I'd think about starting to develop a DP weapon for your destroyers in the near future, as well - something between 105 and 130mm. I'd reccomend the Filipino 115mm myself.

The block co-efficient is too low, I think. 0.38 is as low as I think we accept, and for a destroyer this large, 0.40 may be more appropriate.

Quoted

Originally posted by Alikchi
Ditto Hrolf. Throw on a battery of, say, four 88mm AA guns. The protection doesn't matter so much for a ship of this size and speed.

I'd think about starting to develop a DP weapon for your destroyers in the near future, as well - something between 105 and 130mm. I'd reccomend the Filipino 115mm myself.

My main concern is the speed. This is a porjected replacement for the Capitan Valdes Class and I expect to build ten Valdes until later in the decade.

The idea of a DP is more than welcomed and indeed it makes sense for the projected date of this design to make it's appearance (193. The problem is the caliber. Pretty much the 88mm, the 37mm and 25mm guns AA and the 150mm are standard in the Peruvian Navy. With the bunch of new ships in the fleet in the 1930's using those calibers I have my doubts in bringing another caliber to the fleet and making the supply more difficult for us. Especially a caliber used by a nation that could stop my supply and them I have a bunch of destroyers without ammo in any extended conflict. Nothing personal, just logistics. :-)

This is how the ship looks after the changes recommended. Now I'm not sure is so good of an idea. The speed still is 36 knots but is over 50 tons heavier than the Valdes Class with less protection and no significative armament increase.


Terror, Peru Destroyer laid down 1938

Displacement:
1,937 t light; 2,026 t standard; 2,261 t normal; 2,449 t full load

Dimensions: Length overall / water x beam x draught
396.00 ft / 396.00 ft x 36.60 ft x 14.00 ft (normal load)
120.70 m / 120.70 m x 11.16 m x 4.27 m

Armament:
4 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1938 Model
Breech loading guns in deck mounts with hoists
on centreline, evenly spread, 2 raised mounts
Aft Main mounts separated by engine room
4 - 3.46" / 88.0 mm guns in single mounts, 20.79lbs / 9.43kg shells, 1938 Model
Anti-aircraft guns in deck mounts
on side ends, evenly spread
4 - 0.98" / 25.0 mm guns in single mounts, 0.48lbs / 0.22kg shells, 1938 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 497 lbs / 225 kg
Shells per gun, main battery: 150
8 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.79" / 20 mm - -
2nd: 0.39" / 10 mm - -
3rd: 0.39" / 10 mm - -

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 51,454 shp / 38,385 Kw = 36.00 kts
Range 5,000nm at 15.00 kts
Bunker at max displacement = 423 tons

Complement:
163 - 213

Cost:
£1.576 million / $6.304 million

Distribution of weights at normal displacement:
Armament: 62 tons, 2.7 %
Armour: 12 tons, 0.5 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 12 tons, 0.5 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 1,140 tons, 50.4 %
Hull, fittings & equipment: 723 tons, 32.0 %
Fuel, ammunition & stores: 324 tons, 14.3 %
Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
585 lbs / 265 Kg = 5.7 x 5.9 " / 150 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.35
Metacentric height 1.9 ft / 0.6 m
Roll period: 11.2 seconds
Steadiness - As gun platform (Average = 50 %): 53 %
- Recoil effect (Restricted arc if above 1.00): 0.54
Seaboat quality (Average = 1.00): 1.00

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.390
Length to Beam Ratio: 10.82 : 1
'Natural speed' for length: 22.90 kts
Power going to wave formation at top speed: 66 %
Trim (Max stability = 0, Max steadiness = 100): 53
Bow angle (Positive = bow angles forward): 0.00 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 (25 %): 21.00 ft / 6.40 m
- Mid (40 %): 20.00 ft / 6.10 m (12.00 ft / 3.66 m aft of break)
- Quarterdeck (15 %): 12.00 ft / 3.66 m
- Stern: 12.00 ft / 3.66 m
- Average freeboard: 15.93 ft / 4.85 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 183.8 %
- Above water (accommodation/working, high = better): 94.2 %
Waterplane Area: 9,209 Square feet or 856 Square metres
Displacement factor (Displacement / loading): 68 %
Structure weight / hull surface area: 40 lbs/sq ft or 194 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.86
- Overall: 0.57
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate

Hmmm... how about scaling down the design? You already have a large destroyer type in the Valdes. Peru should go for cheap, IMHO. How about dropping two 150mm guns and a quadruple torp launcher and scaling down to, say, 1200tons?

Understood re: logistics.

Quoted

Originally posted by Alikchi
Hmmm... how about scaling down the design? You already have a large destroyer type in the Valdes. Peru should go for cheap, IMHO. How about dropping two 150mm guns and a quadruple torp launcher and scaling down to, say, 1200tons?

Understood re: logistics.

And possible going heavier with the Libertad Class. Will try it and see what it comes out.

small point, 396 feet requires a type 2 slip or drydock.....

393 is the limit for type 1!!

3-4 feet shouldn't be a problem to trim off, you could also cut a knot or two of speed. 34 knots is still respectable and your hull strength will come up as a result.

The main concern is, why build this ship if we have the Capitan Valdes Class? Is supposed to be a replacement of the Valdeses but it had no advantages except for speed while it less armor protection and AA armament. I guess this is turning into one of those projects that stay in the designing table.

I'd say Alikchi hit the nail on the head, go for a cheaper smaller design arond 1,400-1,500 tons. I'd also suggest a DP mount as well rather than a mixed armament of 150 and 88mm.

Why replace the Valdez at all? It is only a few years old. The Vaquez from South Africa might need replacing in the near future, but replacing those with more Valdez might be worth considering. Of course that depends on what you want as an improvement on the Valdez design.

More speed?

More range? (why?)

More firepower?

More anti-sub ability?

More anti-air ability?

More numbers?

More intimidating?

Why replacements in 1938?

Quoted

Originally posted by Ithekro
Why replace the Valdez at all? It is only a few years old. The Vaquez from South Africa might need replacing in the near future, but replacing those with more Valdez might be worth considering. Of course that depends on what you want as an improvement on the Valdez design.

More speed?

More range? (why?)

More firepower?

More anti-sub ability?

More anti-air ability?

More numbers?

More intimidating?

Why replacements in 1938?

I'm trying more speed and in reality is not a replacement for the Valdes, is more a ship do build after the Valdeses production run is finished.

The Valdeses will be around for a long while, it's also a question of numbers. Right now in 1933 is IIRC 1.5:1 in favor of capital ships versus destroyers and it needs to be the opposite at least. Will work in a brand new design in the 1200-1300 range and will see who can sell me DP guns (look in the direction of Iberia) but of course all this is way into the future of WW. I don't see this ship even laid down until 1938 at the earliest.

Thanks everyone. It was to see the feasibility of building this design and has being pretty much a resounding no. Back to the board. :-)

An interesting note. It seems Peru is going for speed while Chile is going for firepower. Interesting. I wonder what that would mean in the real world?

Here is a smaller sized destroyer with Iberian DP caliber guns.


Terror, Peru Destroyer laid down 1938

Displacement:
1,348 t light; 1,396 t standard; 1,461 t normal; 1,512 t full load

Dimensions: Length overall / water x beam x draught
355.00 ft / 355.00 ft x 32.00 ft x 10.00 ft (normal load)
108.20 m / 108.20 m x 9.75 m x 3.05 m

Armament:
4 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.92kg shells, 1938 Model
Dual purpose guns in deck mounts with hoists
on centreline ends, evenly spread, 2 raised mounts - superfiring
4 - 1.46" / 37.0 mm guns in single mounts, 1.55lbs / 0.70kg shells, 1938 Model
Anti-aircraft guns in deck mounts
on side, all amidships
4 - 0.98" / 25.0 mm guns in single mounts, 0.48lbs / 0.22kg shells, 1938 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 219 lbs / 99 kg
Shells per gun, main battery: 150
8 - 21.0" / 533.4 mm above water torpedoes

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 3 shafts, 38,346 shp / 28,606 Kw = 35.00 kts
Range 4,000nm at 10.00 kts
Bunker at max displacement = 116 tons

Complement:
117 - 153

Cost:
£0.989 million / $3.957 million

Distribution of weights at normal displacement:
Armament: 27 tons, 1.9 %
Machinery: 752 tons, 51.5 %
Hull, fittings & equipment: 548 tons, 37.5 %
Fuel, ammunition & stores: 113 tons, 7.7 %
Miscellaneous weights: 20 tons, 1.4 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
478 lbs / 217 Kg = 9.1 x 4.7 " / 120 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.25
Metacentric height 1.4 ft / 0.4 m
Roll period: 11.6 seconds
Steadiness - As gun platform (Average = 50 %): 52 %
- Recoil effect (Restricted arc if above 1.00): 0.53
Seaboat quality (Average = 1.00): 1.03

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.450
Length to Beam Ratio: 11.09 : 1
'Natural speed' for length: 21.46 kts
Power going to wave formation at top speed: 69 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 0.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 21.00 ft / 6.40 m
- Forecastle (20 %): 16.00 ft / 4.88 m
- Mid (45 %): 16.00 ft / 4.88 m (15.00 ft / 4.57 m aft of break)
- Quarterdeck (30 %): 15.00 ft / 4.57 m
- Stern: 15.00 ft / 4.57 m
- Average freeboard: 15.85 ft / 4.83 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 182.1 %
- Above water (accommodation/working, high = better): 97.8 %
Waterplane Area: 7,527 Square feet or 699 Square metres
Displacement factor (Displacement / loading): 62 %
Structure weight / hull surface area: 35 lbs/sq ft or 169 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 2.63
- Overall: 0.59
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate

Definitively your best design yet - and see, with a bc quite a bit above 0,4. ;o) L:B ratio is really high but acceptable.

Here is the same design with 4 more extra torpedo tubes and depth charges attached. As you can see speed is down from the original 36 to 35 but IMO the 12 torpedo tubes make for a formidable battery.

Terror, Peru Destroyer laid down 1938

Displacement:
1,341 t light; 1,389 t standard; 1,461 t normal; 1,518 t full load

Dimensions: Length overall / water x beam x draught
355.00 ft / 355.00 ft x 32.00 ft x 10.00 ft (normal load)
108.20 m / 108.20 m x 9.75 m x 3.05 m

Armament:
4 - 4.72" / 120 mm guns in single mounts, 52.72lbs / 23.91kg shells, 1938 Model
Dual purpose guns in deck mounts with hoists
on centreline ends, evenly spread, 2 raised mounts - superfiring
4 - 1.46" / 37.0 mm guns in single mounts, 1.55lbs / 0.70kg shells, 1938 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
4 - 0.98" / 25.0 mm guns in single mounts, 0.48lbs / 0.22kg shells, 1938 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 219 lbs / 99 kg
Shells per gun, main battery: 150
12 - 21.0" / 533.4 mm above water torpedoes

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 3 shafts, 38,346 shp / 28,606 Kw = 35.00 kts
Range 4,500nm at 10.00 kts
Bunker at max displacement = 129 tons

Complement:
117 - 153

Cost:
£0.988 million / $3.951 million

Distribution of weights at normal displacement:
Armament: 27 tons, 1.9 %
Machinery: 752 tons, 51.5 %
Hull, fittings & equipment: 541 tons, 37.0 %
Fuel, ammunition & stores: 120 tons, 8.2 %
Miscellaneous weights: 20 tons, 1.4 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
460 lbs / 209 Kg = 8.7 x 4.7 " / 120 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.19
Metacentric height 1.2 ft / 0.4 m
Roll period: 12.1 seconds
Steadiness - As gun platform (Average = 50 %): 51 %
- Recoil effect (Restricted arc if above 1.00): 0.55
Seaboat quality (Average = 1.00): 1.02

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.450
Length to Beam Ratio: 11.09 : 1
'Natural speed' for length: 21.46 kts
Power going to wave formation at top speed: 69 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 0.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 21.00 ft / 6.40 m
- Forecastle (20 %): 16.00 ft / 4.88 m
- Mid (45 %): 16.00 ft / 4.88 m (15.00 ft / 4.57 m aft of break)
- Quarterdeck (30 %): 15.00 ft / 4.57 m
- Stern: 15.00 ft / 4.57 m
- Average freeboard: 15.85 ft / 4.83 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 182.1 %
- Above water (accommodation/working, high = better): 51.7 %
Waterplane Area: 7,527 Square feet or 699 Square metres
Displacement factor (Displacement / loading): 62 %
Structure weight / hull surface area: 34 lbs/sq ft or 167 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 2.59
- Overall: 0.58
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is cramped

Additional tonnage is for 20 depth charges and launchers

I´d improve her ammo stocks instead...