Iberian Protected Cruiser Design

[miketr]

PITA....  0.05 meters needed....

Michael

PC-1912 7.2Kb, Iberia Protected Cruiser laid down 1912

Displacement:
   7,061 t light; 7,341 t standard; 8,111 t normal; 8,728 t full load

Dimensions: Length overall / water x beam x draught
   574.15 ft / 574.15 ft x 57.41 ft x 17.22 ft (normal load)
   175.00 m / 175.00 m x 17.50 m  x 5.25 m

Armament:
      10 - 5.91" / 150 mm guns (5x2 guns), 102.98lbs / 46.71kg shells, 1912 Model
     Breech loading guns in deck mounts with hoists
     on centreline ends, majority aft, 3 raised mounts - superfiring
      8 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1912 Model
     Breech loading guns in deck mounts with hoists
     on side, all amidships
      8 - 1.97" / 50.0 mm guns in single mounts, 3.81lbs / 1.73kg shells, 1912 Model
     Quick firing guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 1,163 lbs / 528 kg
   Shells per gun, main battery: 175
   6 - 20.0" / 508 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   2.95" / 75 mm   418.60 ft / 127.59 m   9.84 ft / 3.00 m
   Ends:   Unarmoured
     Main Belt covers 112 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.98" / 25 mm         -         2.95" / 75 mm
   2nd:   0.98" / 25 mm         -               -
   3rd:   0.98" / 25 mm         -               -

   - Armour deck: 1.57" / 40 mm, Conning tower: 3.94" / 100 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 3 shafts, 60,000 shp / 44,760 Kw = 30.25 kts
   Range 10,500nm at 10.00 kts
   Bunker at max displacement = 1,387 tons

Complement:
   426 - 555

Cost:
   £0.704 million / $2.817 million

Distribution of weights at normal displacement:
   Armament: 145 tons, 1.8 %
   Armour: 1,227 tons, 15.1 %
      - Belts: 498 tons, 6.1 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 55 tons, 0.7 %
      - Armour Deck: 640 tons, 7.9 %
      - Conning Tower: 34 tons, 0.4 %
   Machinery: 2,392 tons, 29.5 %
   Hull, fittings & equipment: 3,132 tons, 38.6 %
   Fuel, ammunition & stores: 1,051 tons, 13.0 %
   Miscellaneous weights: 164 tons, 2.0 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     8,634 lbs / 3,916 Kg = 83.8 x 5.9 " / 150 mm shells or 1.2 torpedoes
   Stability (Unstable if below 1.00): 1.25
   Metacentric height 3.3 ft / 1.0 m
   Roll period: 13.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.37
   Seaboat quality  (Average = 1.00): 1.22

Hull form characteristics:
   Hull has low quarterdeck
   Block coefficient: 0.500
   Length to Beam Ratio: 10.00 : 1
   'Natural speed' for length: 23.96 kts
   Power going to wave formation at top speed: 53 %
   Trim (Max stability = 0, Max steadiness = 100): 58
   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:      24.61 ft / 7.50 m
      - Forecastle (20 %):   21.33 ft / 6.50 m
      - Mid (50 %):      17.22 ft / 5.25 m
      - Quarterdeck (15 %):   11.48 ft / 3.50 m (17.22 ft / 5.25 m before break)
      - Stern:      11.48 ft / 3.50 m
      - Average freeboard:   18.06 ft / 5.51 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 112.2 %
      - Above water (accommodation/working, high = better): 158.1 %
   Waterplane Area: 21,963 Square feet or 2,040 Square metres
   Displacement factor (Displacement / loading): 111 %
   Structure weight / hull surface area: 92 lbs/sq ft or 451 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.98
      - Longitudinal: 1.16
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is excellent
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

[Borys]

Very powerfull!
Look good.
Borys

[Sachmle]

Nice, and at that length and freeboard from a distance she's gonna look like an AC. Might scare off some smaller ships.

[miketr]

Nice, and at that length and freeboard from a distance she's gonna look like an AC. Might scare off some smaller ships.

Perhaps but at the same time the silhouette is going to be very distinct.  Of course with her speed and seakeeping few ships will have a chance to run her down.

Speaking of which any comment on the silhouette before I fill in the details?

[Borys]

The silhouette is too modern, IMO.
Isn't she too beamy to have centreline torpedos? And ain't that a waste of space? Maybe Q turret isntead of the lowered quarterdeck?
Borys

[miketr]

The silhouette is too modern, IMO.
Isn't she too beamy to have centreline torpedos? And ain't that a waste of space? Maybe Q turret isntead of the lowered quarterdeck?
Borys

Some IJN cruiser in WW2 had centerline torpedo tubes.  If people think its a problem I could have the launchers broadside they are about 25' long so if there should be enough room for two side by side.  Especially if I have sponsons to support them.  As to look also keep in mind this is a tech of the late 10's / early 20's.   

As to a Q placement the problem is of space.  With 60,000 SHP we are looking at huge firerooms.  I am not sure there would be the space to fit in a mag midships.  Even then it would be right next to at least one fire room.

Any other thoughts?

Michael 

[miketr]

Just noticed that she is to long to fit on a type 2 slipway.  Minor loss of speed

PC-1912 7.2Kc, Iberia Protected Cruiser laid down 1912

Displacement:
   6,948 t light; 7,226 t standard; 8,019 t normal; 8,653 t full load

Dimensions: Length overall / water x beam x draught
   557.74 ft / 557.74 ft x 55.77 ft x 18.04 ft (normal load)
   170.00 m / 170.00 m x 17.00 m  x 5.50 m

Armament:
      10 - 5.91" / 150 mm guns (5x2 guns), 102.98lbs / 46.71kg shells, 1912 Model
     Breech loading guns in deck mounts with hoists
     on centreline ends, majority aft, 3 raised mounts - superfiring
      8 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1912 Model
     Breech loading guns in deck mounts with hoists
     on side, all amidships
      8 - 1.97" / 50.0 mm guns in single mounts, 3.81lbs / 1.73kg shells, 1912 Model
     Quick firing guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 1,163 lbs / 528 kg
   Shells per gun, main battery: 175
   6 - 20.0" / 508 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   2.95" / 75 mm   413.39 ft / 126.00 m   9.84 ft / 3.00 m
   Ends:   Unarmoured
     Main Belt covers 114 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.98" / 25 mm         -         2.95" / 75 mm
   2nd:   0.98" / 25 mm         -               -
   3rd:   0.98" / 25 mm         -               -

   - Armour deck: 1.57" / 40 mm, Conning tower: 3.94" / 100 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 3 shafts, 60,000 shp / 44,760 Kw = 30.23 kts
   Range 11,000nm at 10.00 kts
   Bunker at max displacement = 1,427 tons

Complement:
   423 - 550

Cost:
   £0.700 million / $2.801 million

Distribution of weights at normal displacement:
   Armament: 145 tons, 1.8 %
   Armour: 1,183 tons, 14.8 %
      - Belts: 490 tons, 6.1 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 55 tons, 0.7 %
      - Armour Deck: 604 tons, 7.5 %
      - Conning Tower: 34 tons, 0.4 %
   Machinery: 2,392 tons, 29.8 %
   Hull, fittings & equipment: 3,053 tons, 38.1 %
   Fuel, ammunition & stores: 1,071 tons, 13.4 %
   Miscellaneous weights: 173 tons, 2.2 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     8,221 lbs / 3,729 Kg = 79.8 x 5.9 " / 150 mm shells or 1.2 torpedoes
   Stability (Unstable if below 1.00): 1.22
   Metacentric height 3.0 ft / 0.9 m
   Roll period: 13.5 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.43
   Seaboat quality  (Average = 1.00): 1.23

Hull form characteristics:
   Hull has low quarterdeck
   Block coefficient: 0.500
   Length to Beam Ratio: 10.00 : 1
   'Natural speed' for length: 23.62 kts
   Power going to wave formation at top speed: 54 %
   Trim (Max stability = 0, Max steadiness = 100): 57
   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:      24.61 ft / 7.50 m
      - Forecastle (20 %):   22.15 ft / 6.75 m
      - Mid (50 %):      18.04 ft / 5.50 m
      - Quarterdeck (15 %):   11.48 ft / 3.50 m (18.04 ft / 5.50 m before break)
      - Stern:      11.48 ft / 3.50 m
      - Average freeboard:   18.69 ft / 5.70 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 113.5 %
      - Above water (accommodation/working, high = better): 155.9 %
   Waterplane Area: 20,726 Square feet or 1,926 Square metres
   Displacement factor (Displacement / loading): 110 %
   Structure weight / hull surface area: 92 lbs/sq ft or 449 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.96
      - Longitudinal: 1.32
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is excellent
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily