Planned Battlecruiser for NUS

[Sachmle]

Isla de Pascua Class, NUS Battlecruiser laid down 1910 (Engine 1909)

Displacement:
   18,250 t light; 19,267 t standard; 21,201 t normal; 22,748 t full load

Dimensions: Length overall / water x beam x draught
   557.00 ft / 557.00 ft x 82.00 ft (Bulges 86.00 ft) x 26.25 ft (normal load)
   169.77 m / 169.77 m x 24.99 m (Bulges 26.21 m)  x 8.00 m

Armament:
      6 - 12.00" / 305 mm guns (3x2 guns), 1,000.00lbs / 453.59kg shells, 1910 Model
     Breech loading guns in turrets (on barbettes)
     on centreline, evenly spread
     Aft Main mounts separated by engine room
      14 - 8.00" / 203 mm guns in single mounts, 250.00lbs / 113.40kg shells, 1895 Model
     Breech loading guns in casemate mounts
     on side, evenly spread
     14 guns in hull casemates - Limited use in heavy seas
      18 - 4.00" / 102 mm guns in single mounts, 30.00lbs / 13.61kg shells, 1906 Model
     Quick firing guns in casemate mounts
     on side, evenly spread, 10 raised mounts
     8 guns in hull casemates - Limited use in heavy seas
      4 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1905 Model
     Quick firing guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 10,094 lbs / 4,579 kg
   Shells per gun, main battery: 100
   2 - 18.0" / 457.2 mm submerged torpedo tubes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   11.0" / 279 mm   395.00 ft / 120.40 m   12.00 ft / 3.66 m
   Ends:   4.00" / 102 mm   125.00 ft / 38.10 m   10.00 ft / 3.05 m
     37.00 ft / 11.28 m Unarmoured ends
   Upper:   8.00" / 203 mm   395.00 ft / 120.40 m   8.00 ft / 2.44 m
     Main Belt covers 109 % of normal length

   - Torpedo Bulkhead and Bulges:
      2.00" / 51 mm   395.00 ft / 120.40 m   26.00 ft / 7.92 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   13.0" / 330 mm   10.0" / 254 mm      12.0" / 305 mm
   2nd:   4.00" / 102 mm         -         2.00" / 51 mm
   3rd:   4.00" / 102 mm         -         2.00" / 51 mm
   4th:   1.00" / 25 mm         -               -

   - Armour deck: 1.00" / 25 mm, Conning tower: 10.00" / 254 mm

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 4 shafts, 47,931 shp / 35,757 Kw = 24.00 kts
   Range 6,500nm at 12.00 kts
   Bunker at max displacement = 3,481 tons (100% coal)

Complement:
   878 - 1,142

Cost:
   £1.961 million / $7.844 million

Distribution of weights at normal displacement:
   Armament: 1,175 tons, 5.5 %
   Armour: 7,024 tons, 33.1 %
      - Belts: 3,488 tons, 16.5 %
      - Torpedo bulkhead: 760 tons, 3.6 %
      - Armament: 1,998 tons, 9.4 %
      - Armour Deck: 612 tons, 2.9 %
      - Conning Tower: 165 tons, 0.8 %
   Machinery: 2,397 tons, 11.3 %
   Hull, fittings & equipment: 7,454 tons, 35.2 %
   Fuel, ammunition & stores: 2,951 tons, 13.9 %
   Miscellaneous weights: 200 tons, 0.9 %
                Misc Weight as follows:
                -50t Flag facilities
                -25t W/T
                -50t Crew comfort measures
                -48t 24 total torps, including reloads
                -27t Weight reserve

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     27,216 lbs / 12,345 Kg = 31.5 x 12.0 " / 305 mm shells or 4.4 torpedoes
   Stability (Unstable if below 1.00): 1.20
   Metacentric height 5.2 ft / 1.6 m
   Roll period: 15.8 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.57
   Seaboat quality  (Average = 1.00): 1.36

Hull form characteristics:
   Hull has raised forecastle
   Block coefficient: 0.590
   Length to Beam Ratio: 6.48 : 1
   'Natural speed' for length: 23.60 kts
   Power going to wave formation at top speed: 52 %
   Trim (Max stability = 0, Max steadiness = 100): 52
   Bow angle (Positive = bow angles forward): -5.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      23.00 ft / 7.01 m
      - Forecastle (15 %):   22.00 ft / 6.71 m (21.00 ft / 6.40 m aft of break)
      - Mid (60 %):      20.00 ft / 6.10 m
      - Quarterdeck (15 %):   20.00 ft / 6.10 m
      - Stern:      20.00 ft / 6.10 m
      - Average freeboard:   20.59 ft / 6.27 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 107.3 %
      - Above water (accommodation/working, high = better): 145.9 %
   Waterplane Area: 33,098 Square feet or 3,075 Square metres
   Displacement factor (Displacement / loading): 99 %
   Structure weight / hull surface area: 153 lbs/sq ft or 747 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.94
      - Longitudinal: 1.64
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is excellent
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

[The Rock Doctor]

Nice work on the picture; a very unique looking ship.

I'm not sure 8" secondaries are a good choice - large and slowish if anti-TB weapons.  On the other hand, if you're looking at them as part of the main battery, I guess they'd be worth considering.

I do like the high freeboard, it seems appropriate for the southerly location.

[Sachmle]

Intended as battle line ship, as NUS not enough capasity to use as independent station ship, so the 8" would be employed to engage cruisers while the 12" would be for BBs/BCs.  Engage multiple targets at once.

[P3D]

I'd say the problem is rather the casemates for the 8"s. Perhaps twin turrets instead?

[Sachmle]

That's the 'flaw' of NUS' first attempt at a BC, which some are calling a "Fast Battleship" because they think her armor is to thick.
This is a Battleship on this hull:

Gran Chaco, NUS Battleship laid down 1911 (Engine 1909)

Displacement:
   19,230 t light; 20,371 t standard; 22,377 t normal; 23,982 t full load

Dimensions: Length overall / water x beam x draught
   557.00 ft / 557.00 ft x 82.00 ft (Bulges 86.00 ft) x 26.25 ft (normal load)
   169.77 m / 169.77 m x 24.99 m (Bulges 26.21 m)  x 8.00 m

Armament:
      6 - 13.50" / 343 mm guns (3x2 guns), 1,300.00lbs / 589.67kg shells, 1911 Model
     Breech loading guns in turrets (on barbettes)
     on centreline, evenly spread
     Aft Main mounts separated by engine room
      14 - 8.00" / 203 mm guns in single mounts, 250.00lbs / 113.40kg shells, 1895 Model
     Breech loading guns in casemate mounts
     on side, evenly spread
     14 guns in hull casemates - Limited use in heavy seas
      18 - 4.00" / 102 mm guns in single mounts, 30.00lbs / 13.61kg shells, 1906 Model
     Quick firing guns in casemate mounts
     on side, evenly spread, 10 raised mounts
     8 guns in hull casemates - Limited use in heavy seas
      4 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1905 Model
     Quick firing guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 11,894 lbs / 5,395 kg
   Shells per gun, main battery: 100
   2 - 18.0" / 457.2 mm submerged torpedo tubes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   13.0" / 330 mm   395.00 ft / 120.40 m   12.00 ft / 3.66 m
   Ends:   6.00" / 152 mm   125.00 ft / 38.10 m   10.00 ft / 3.05 m
     37.00 ft / 11.28 m Unarmoured ends
   Upper:   10.0" / 254 mm   395.00 ft / 120.40 m   8.00 ft / 2.44 m
     Main Belt covers 109 % of normal length

   - Torpedo Bulkhead and Bulges:
      2.00" / 51 mm   395.00 ft / 120.40 m   26.00 ft / 7.92 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   13.0" / 330 mm   10.0" / 254 mm      12.0" / 305 mm
   2nd:   4.00" / 102 mm         -         2.00" / 51 mm
   3rd:   4.00" / 102 mm         -         2.00" / 51 mm
   4th:   1.00" / 25 mm         -               -

   - Armour deck: 1.50" / 38 mm, Conning tower: 10.00" / 254 mm

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 2 shafts, 24,853 shp / 18,540 Kw = 20.00 kts
   Range 6,500nm at 12.00 kts
   Bunker at max displacement = 3,611 tons (100% coal)

Complement:
   914 - 1,189

Cost:
   £2.065 million / $8.258 million

Distribution of weights at normal displacement:
   Armament: 1,449 tons, 6.5 %
   Armour: 8,370 tons, 37.4 %
      - Belts: 4,259 tons, 19.0 %
      - Torpedo bulkhead: 760 tons, 3.4 %
      - Armament: 2,233 tons, 10.0 %
      - Armour Deck: 947 tons, 4.2 %
      - Conning Tower: 171 tons, 0.8 %
   Machinery: 1,243 tons, 5.6 %
   Hull, fittings & equipment: 7,968 tons, 35.6 %
   Fuel, ammunition & stores: 3,147 tons, 14.1 %
   Miscellaneous weights: 200 tons, 0.9 %
          Misc Weight as follows:
            -50t Flag facilities
            -25t W/T
            -75t Crew Comfort measures
            -50t Weight reserve

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     33,590 lbs / 15,236 Kg = 27.3 x 13.5 " / 343 mm shells or 5.6 torpedoes
   Stability (Unstable if below 1.00): 1.23
   Metacentric height 5.4 ft / 1.6 m
   Roll period: 15.5 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.67
   Seaboat quality  (Average = 1.00): 1.71

Hull form characteristics:
   Hull has raised forecastle
   Block coefficient: 0.623
   Length to Beam Ratio: 6.48 : 1
   'Natural speed' for length: 23.60 kts
   Power going to wave formation at top speed: 43 %
   Trim (Max stability = 0, Max steadiness = 100): 41
   Bow angle (Positive = bow angles forward): -5.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      23.00 ft / 7.01 m
      - Forecastle (15 %):   22.00 ft / 6.71 m (21.00 ft / 6.40 m aft of break)
      - Mid (60 %):      20.00 ft / 6.10 m
      - Quarterdeck (15 %):   20.00 ft / 6.10 m
      - Stern:      20.00 ft / 6.10 m
      - Average freeboard:   20.59 ft / 6.27 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 91.6 %
      - Above water (accommodation/working, high = better): 144.5 %
   Waterplane Area: 34,124 Square feet or 3,170 Square metres
   Displacement factor (Displacement / loading): 99 %
   Structure weight / hull surface area: 160 lbs/sq ft or 780 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.94
      - Longitudinal: 1.66
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   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

[Korpen]

That's the 'flaw' of NUS' first attempt at a BC, which some are calling a "Fast Battleship" because they think her armor is to thick.
This is a Battleship on this hull:

Gran Chaco, NUS Battleship laid down 1911 (Engine 1909)

Her nice and high freeboard and excellent seakeeping is definite pros.
However I find her over armoured (as is allot of the ships here) and under gunned. While it is nice to have a belt that can stop a 35cm shell at less then 50hm (and a APC at less then 95hm), it is really a bit overkill. I would advice thinning the belts, and add some more deck armour, as that that is quite thin. Extending the end belt to cover the entire waterline would be prudent as well, even if it means thinning it somewhat.

About engaging cruisers with the 20cm casemate guns, what sort of cruisers are you thinking about?
According to the was I see it (and I know some disagree); For smaller (<5000ton) cruisers 15cm (12cm might work as well) guns should be enough, and for cruisers larger then that, well, they are worth to use the main battery on. If need be the main battery can split fire after all.

[Sachmle]

Gran Chacos is a pipe dream, for at least 2-3 yrs as I don't have the resources nor equipment to make her work.  As far as the 8" secondary/cruisers statement I planned Isla de Pascua w/ a very specific goal in mind. While I would prefer not share said goal, lets just say she's purpose built as a one up of something else. I could go w/ 7" secondaries, but they are almost as slow firing and about 2/3 the shell weight, so I figured what the hell. When I get some time I'll look at a 7" and 6" varient and see what works. Thank you all for your honest imput.

[Sachmle]

Also, I now admit defeat, she is a Fast BB. Happy Tanthalas? ;D

[maddox]

With 20 kts she's a normal BB in my book.

[Sachmle]

20knt is Grand Chaco, a regular BB, Isla de Pascua is 24knts and that is the one I was referring to.

[Tanthalas]

Also, I now admit defeat, she is a Fast BB. Happy Tanthalas? ;D

HEHEHE YUP

[Sachmle]

Final Version to be built:

Isla de Pascua Class, NUS Battlecruiser laid down 1909

Displacement:
   17,850 t light; 18,748t standard; 20,795 t normal; 22,435 t full load

Dimensions: Length overall / water x beam x draught
   557.00 ft / 557.00 ft x 84.00 ft x 26.25 ft (normal load)
   169.77 m / 169.77 m x 25.60 m  x 8.00 m

Armament:
      6 - 12.00" / 305 mm guns (3x2 guns), 865.70lbs / 391.90kg shells, 1905 Model
     Breech loading guns in turrets (on barbettes)
     on centreline, evenly spread
     Aft Main mounts separated by engine room
      14 - 7.00" / 178 mm guns in single mounts, 170.00lbs / 77.11kg shells, 1890 Model
     Breech loading guns in casemate mounts
     on side, evenly spread
     14 guns in hull casemates - Limited use in heavy seas
      18 - 4.00" / 102 mm guns in single mounts, 30.00lbs / 13.61kg shells, 1906 Model
     Quick firing guns in casemate mounts
     on side, evenly spread, 10 raised mounts
     8 guns in hull casemates - Limited use in heavy seas
      4 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1905 Model
     Quick firing guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 8,158 lbs / 3,700 kg
   Shells per gun, main battery: 100
   2 - 18.0" / 457.2 mm submerged torpedo tubes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   10.0" / 254 mm   400.00 ft / 121.92 m   12.00 ft / 3.66 m
   Ends:   4.00" / 102 mm   130.00 ft / 39.62 m   10.00 ft / 3.05 m
     27.00 ft / 8.23 m Unarmoured aft
   Upper:   6.00" / 152 mm   400.00 ft / 121.92 m   8.00 ft / 2.44 m
     Main Belt covers 110 % of normal length

   - Torpedo Bulkhead:
      1.50" / 38 mm   400.00 ft / 121.92 m   30.00 ft / 9.14 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   12.0" / 305 mm   10.0" / 254 mm      12.0" / 305 mm
   2nd:   4.00" / 102 mm         -         2.00" / 51 mm
   3rd:   4.00" / 102 mm         -         2.00" / 51 mm
   4th:   1.00" / 25 mm         -               -

   - Armour deck: 2.00" / 51 mm, Conning tower: 11.00" / 279 mm

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 4 shafts, 47,245 shp / 35,245 Kw = 24.00 kts
   Range 7,000nm at 12.00 kts
   Bunker at max displacement = 3,689 tons (100% coal)

Complement:
   865 - 1,125

Cost:
   £1.818 million / $7.273 million

Distribution of weights at normal displacement:
   Armament: 1,027 tons, 4.9 %
   Armour: 7,098 tons, 34.1 %
      - Belts: 3,057 tons, 14.7 %
      - Torpedo bulkhead: 666 tons, 3.2 %
      - Armament: 1,938 tons, 9.3 %
      - Armour Deck: 1,258 tons, 6.0 %
      - Conning Tower: 179 tons, 0.9 %
   Machinery: 2,362 tons, 11.4 %
   Hull, fittings & equipment: 7,165 tons, 34.5 %
   Fuel, ammunition & stores: 2,946 tons, 14.2 %
   Miscellaneous weights: 200 tons, 1.0 %
                Misc Weight as follows:
                -50t Flag facilities
                -25t W/T
                -50t Crew Comfort measures
                -48t For 24 total torpedos
                -27t Weight Reserve

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     28,842 lbs / 13,083 Kg = 33.4 x 12.0 " / 305 mm shells or 4.6 torpedoes
   Stability (Unstable if below 1.00): 1.19
   Metacentric height 5.3 ft / 1.6 m
   Roll period: 15.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.52
   Seaboat quality  (Average = 1.00): 1.37

Hull form characteristics:
   Hull has raised forecastle
   Block coefficient: 0.593
   Length to Beam Ratio: 6.63 : 1
   'Natural speed' for length: 23.60 kts
   Power going to wave formation at top speed: 51 %
   Trim (Max stability = 0, Max steadiness = 100): 51
   Bow angle (Positive = bow angles forward): -5.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      23.00 ft / 7.01 m
      - Forecastle (15 %):   22.00 ft / 6.71 m (21.00 ft / 6.40 m aft of break)
      - Mid (60 %):      20.00 ft / 6.10 m
      - Quarterdeck (15 %):   20.00 ft / 6.10 m
      - Stern:      20.00 ft / 6.10 m
      - Average freeboard:   20.59 ft / 6.27 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 100.6 %
      - Above water (accommodation/working, high = better): 152.1 %
   Waterplane Area: 33,988 Square feet or 3,158 Square metres
   Displacement factor (Displacement / loading): 103 %
   Structure weight / hull surface area: 147 lbs/sq ft or 716 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.95
      - Longitudinal: 1.63
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is excellent
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

[Walter]

You're not going to close those gaps that exist between the main belt and the end belts?

[Carthaginian]

Really like the layout... boiler room layout looks strange, but it's definately original.
The armament is heavy enough to trash older battleships, and the speed is enough to take on most older cruisers. She has enough light guns not to need much of an escort, and she has armor enough to take a good beating.

I like her... the art is especially nice as well.

[Borys]

Cute!