Iberian AC 1916

[miketr]

I am thinking about building another set of 250mm armed armored cruisers in 1916.  Mission isn't to take on the Battle Cruisers but to function as a protected / light cruiser killer.

I don't like her stability though so I will attempt a redesign.   I want to keep the size down to a type 2 slip and displacement as low as possible.

Any thoughts?

AC-1916, Iberia Armored Cruiser laid down 1916 (Engine 1912)

Displacement:
   15,490 t light; 16,153 t standard; 18,161 t normal; 19,767 t full load

Dimensions: Length overall / water x beam x draught
   562.37 ft / 557.74 ft x 72.18 ft x 28.71 ft (normal load)
   171.41 m / 170.00 m x 22.00 m  x 8.75 m

Armament:
      8 - 9.84" / 250 mm guns in single mounts, 476.75lbs / 216.25kg shells, 1916 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread, 4 raised mounts - superfiring
      8 - 5.91" / 150 mm guns (4x2 guns), 102.98lbs / 46.71kg shells, 1916 Model
     Breech loading guns in deck mounts with hoists
     on side, all amidships
      4 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1916 Model
     Breech loading guns in deck mounts with hoists
     on centreline, all amidships
      8 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1916 Model
     Breech loading guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 5,153 lbs / 2,337 kg
   Shells per gun, main battery: 100
   4 - 20.0" / 508 mm submerged torpedo tubes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   6.50" / 165 mm   459.32 ft / 140.00 m   10.07 ft / 3.07 m
   Ends:   1.97" / 50 mm     98.43 ft / 30.00 m   10.07 ft / 3.07 m
   Upper:   1.97" / 50 mm   362.53 ft / 110.50 m   8.01 ft / 2.44 m
     Main Belt covers 127 % of normal length

   - Torpedo Bulkhead:
      1.97" / 50 mm   362.53 ft / 110.50 m   25.59 ft / 7.80 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   6.50" / 165 mm   4.72" / 120 mm      6.50" / 165 mm
   2nd:   0.98" / 25 mm         -               -
   3rd:   0.98" / 25 mm         -               -
   4th:   0.98" / 25 mm         -               -

   - Armour deck: 2.95" / 75 mm, Conning tower: 6.50" / 165 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 80,001 shp / 59,681 Kw = 28.25 kts
   Range 18,000nm at 10.00 kts
   Bunker at max displacement = 3,614 tons

Complement:
   781 - 1,016

Cost:
   £2.503 million / $10.013 million

Distribution of weights at normal displacement:
   Armament: 644 tons, 3.5 %
   Armour: 5,060 tons, 27.9 %
      - Belts: 1,545 tons, 8.5 %
      - Torpedo bulkhead: 676 tons, 3.7 %
      - Armament: 1,208 tons, 6.7 %
      - Armour Deck: 1,535 tons, 8.5 %
      - Conning Tower: 97 tons, 0.5 %
   Machinery: 3,190 tons, 17.6 %
   Hull, fittings & equipment: 6,254 tons, 34.4 %
   Fuel, ammunition & stores: 2,671 tons, 14.7 %
   Miscellaneous weights: 342 tons, 1.9 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     20,951 lbs / 9,503 Kg = 43.9 x 9.8 " / 250 mm shells or 3.0 torpedoes
   Stability (Unstable if below 1.00): 1.06
   Metacentric height 3.4 ft / 1.0 m
   Roll period: 16.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.80
   Seaboat quality  (Average = 1.00): 1.10

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.550
   Length to Beam Ratio: 7.73 : 1
   'Natural speed' for length: 23.62 kts
   Power going to wave formation at top speed: 57 %
   Trim (Max stability = 0, Max steadiness = 100): 45
   Bow angle (Positive = bow angles forward): 10.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      26.25 ft / 8.00 m
      - Forecastle (20 %):   25.43 ft / 7.75 m
      - Mid (50 %):      24.61 ft / 7.50 m (21.33 ft / 6.50 m aft of break)
      - Quarterdeck (15 %):   20.51 ft / 6.25 m
      - Stern:      19.69 ft / 6.00 m
      - Average freeboard:   22.99 ft / 7.01 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 124.0 %
      - Above water (accommodation/working, high = better): 156.3 %
   Waterplane Area: 28,095 Square feet or 2,610 Square metres
   Displacement factor (Displacement / loading): 107 %
   Structure weight / hull surface area: 136 lbs/sq ft or 663 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.93
      - Longitudinal: 1.89
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is excellent

Range @ 12 knots 12,400 nm
Range @ 15 knots 7,400 nm
Range @ 20 knots 3,600 nm
Range @ 28.25 knots 1,300 nm

[Korpen]

If you are out to kill light cruiser I think it would be a good idea to reduce protection to get more speed.
I would also drop the torpedo bulkhead; the protective zones would be so small that I doubt it would do much good. I also suspect that the difference in underwater survivability would be quite marginal (would guess 2-2,5 without the TB). The weight saved could be used for more speed and/or more extensive armour.

[miketr]

I am limited to 1912 engine tech till I figure 1918 when I can get the next step so 80,000 shp is the max engine power I can work with.

I agree that the torpedo bulkhead is odds are going to be limited use and I am more than likely going to ditch it in a redesign.  My main worry is I am attempting to improve the designs stability.

Michael

[Korpen]

I agree that the torpedo bulkhead is odds are going to be limited use and I am more than likely going to ditch it in a redesign.  My main worry is I am attempting to improve the designs stability.

Michael

Would mounting the guns in twin turrets rather the singles help? :)

[miketr]

That would make too much sense...

Michael

[miketr]

OK I fixed the turrets and deleted the torpedo belt.  I put the extra structure into more range.

AC-1916, Iberia Armored Cruiser laid down 1916 (Engine 1912)

Displacement:
   14,744 t light; 15,407 t standard; 18,161 t normal; 20,363 t full load

Dimensions: Length overall / water x beam x draught
   562.37 ft / 557.74 ft x 72.18 ft x 28.71 ft (normal load)
   171.41 m / 170.00 m x 22.00 m  x 8.75 m

Armament:
      8 - 9.84" / 250 mm guns (4x2 guns), 476.75lbs / 216.25kg shells, 1916 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      8 - 5.91" / 150 mm guns (4x2 guns), 102.98lbs / 46.71kg shells, 1916 Model
     Breech loading guns in deck mounts with hoists
     on side, all amidships
      4 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1916 Model
     Breech loading guns in deck mounts with hoists
     on side, evenly spread
      8 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1916 Model
     Breech loading guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 5,153 lbs / 2,337 kg
   Shells per gun, main battery: 100
   4 - 20.0" / 508 mm submerged torpedo tubes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   6.50" / 165 mm   362.53 ft / 110.50 m   10.20 ft / 3.11 m
   Ends:   1.97" / 50 mm   195.18 ft / 59.49 m   10.20 ft / 3.11 m
   Upper:   1.97" / 50 mm   362.53 ft / 110.50 m   8.01 ft / 2.44 m
     Main Belt covers 100 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   6.50" / 165 mm   4.72" / 120 mm      6.50" / 165 mm
   2nd:   0.98" / 25 mm         -               -
   3rd:   0.98" / 25 mm         -               -
   4th:   0.98" / 25 mm         -               -

   - Armour deck: 2.95" / 75 mm, Conning tower: 6.50" / 165 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 80,001 shp / 59,681 Kw = 28.25 kts
   Range 25,000nm at 10.00 kts
   Bunker at max displacement = 4,956 tons

Complement:
   781 - 1,016

Cost:
   £2.461 million / $9.842 million

Distribution of weights at normal displacement:
   Armament: 644 tons, 3.5 %
   Armour: 4,076 tons, 22.4 %
      - Belts: 1,417 tons, 7.8 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 1,028 tons, 5.7 %
      - Armour Deck: 1,535 tons, 8.5 %
      - Conning Tower: 97 tons, 0.5 %
   Machinery: 3,190 tons, 17.6 %
   Hull, fittings & equipment: 6,295 tons, 34.7 %
   Fuel, ammunition & stores: 3,416 tons, 18.8 %
   Miscellaneous weights: 540 tons, 3.0 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     20,512 lbs / 9,304 Kg = 43.0 x 9.8 " / 250 mm shells or 2.1 torpedoes
   Stability (Unstable if below 1.00): 1.08
   Metacentric height 3.5 ft / 1.1 m
   Roll period: 16.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 51 %
         - Recoil effect (Restricted arc if above 1.00): 0.76
   Seaboat quality  (Average = 1.00): 1.12

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.550
   Length to Beam Ratio: 7.73 : 1
   'Natural speed' for length: 23.62 kts
   Power going to wave formation at top speed: 57 %
   Trim (Max stability = 0, Max steadiness = 100): 45
   Bow angle (Positive = bow angles forward): 10.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      26.25 ft / 8.00 m
      - Forecastle (20 %):   25.43 ft / 7.75 m
      - Mid (50 %):      23.79 ft / 7.25 m (20.51 ft / 6.25 m aft of break)
      - Quarterdeck (15 %):   19.69 ft / 6.00 m
      - Stern:      19.69 ft / 6.00 m
      - Average freeboard:   22.52 ft / 6.86 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 90.9 %
      - Above water (accommodation/working, high = better): 152.0 %
   Waterplane Area: 28,095 Square feet or 2,610 Square metres
   Displacement factor (Displacement / loading): 112 %
   Structure weight / hull surface area: 137 lbs/sq ft or 671 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.92
      - Longitudinal: 2.02
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is excellent

Range @ 12 knots 17,000 nm
Range @ 15 knots 10,200 nm
Range @ 20 knots 4,900 nm
Range @ 28.25 knots 1,840 nm

[Jefgte]

A kind of short VDT  ;)

171.41 m / 170.00

ol inf. to 170 for type2

Range 25,000nm at 10.00 kts

Great range .
IMO, decrease range & increase slightly the belt protections

Seaboat quality  (Average = 1.00): 1.12

1.20 is certainly possible (too great free board ?)

;)

[miketr]

It was my understanding that its waterline length for slipways and drydocks.

Belt armor is to defend against lighter weapons.  There isn't anything in the 250mm L50 class to judge against on navweaps.  Otherwise I figure 165mm armor should provide protection vs. 170mm and smaller weapons from any battle range.

If I increase freebord it costs me stability.  27 knots would be good for the 1.2 seakeeping.

Michael

[Korpen]

1.20 is certainly possible (too great free board ?)

Would be wasteful to try and get, she is a more then good enogh seaboat as she is.

[Borys]

Overall length counts. It's in the rules somewhere ...

For a 250/L50 - maybe compare it with
http://www.navweaps.com/Weapons/WNIT_10-45_M1908.htm
or
http://www.navweaps.com/Weapons/WNBR_10-45_mk6-7.htm

Borys

[Walter]

Overall length counts. It's in the rules somewhere ...

Weill if that's the case, a slip should not be too much of a problem, but a dock is something different.

[Jefgte]

If I increase freebord

not increase... but decrease

lenght 170m max for type 2 DD ...
If not, impossible to close the doors  :D :D :D


;)

[Borys]

http://www.navalism.org/index.php?topic=2965.msg30705#msg30705

A ship may be built in either a slipway or drydock.  The ship's overall length - not waterline length - determines the minimum size of slip or dock necessary for the task.  A slip or dock can only build one warship at a time.

[miketr]

For a 250/L50 - maybe compare it with
http://www.navweaps.com/Weapons/WNIT_10-45_M1908.htm
or
http://www.navweaps.com/Weapons/WNBR_10-45_mk6-7.htm

Borys

The problem is thats near point blank range...  3,000 yards.  I have the NaB program but I haven't used it in so long I can't fill in the data.  What I wonder is what IZ I would have vs. a 250mm 500lb AP shell?  I suspect that I should be good from 8 or 10K out which is al I want. 

Michael

[miketr]

http://www.navalism.org/index.php?topic=2965.msg30705#msg30705

A ship may be built in either a slipway or drydock.  The ship's overall length - not waterline length - determines the minimum size of slip or dock necessary for the task.  A slip or dock can only build one warship at a time.

What a pain in the ass... 

AC-1916c, Iberia Armored Cruiser laid down 1916 (Engine 1912)

Displacement:
   14,615 t light; 15,275 t standard; 18,010 t normal; 20,198 t full load

Dimensions: Length overall / water x beam x draught
   557.74 ft / 553.12 ft x 72.18 ft x 28.71 ft (normal load)
   170.00 m / 168.59 m x 22.00 m  x 8.75 m

Armament:
      8 - 9.84" / 250 mm guns (4x2 guns), 476.75lbs / 216.25kg shells, 1916 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      8 - 5.91" / 150 mm guns (4x2 guns), 102.98lbs / 46.71kg shells, 1916 Model
     Breech loading guns in deck mounts with hoists
     on side, all amidships
      4 - 5.91" / 150 mm guns in single mounts, 102.98lbs / 46.71kg shells, 1916 Model
     Breech loading guns in deck mounts with hoists
     on side, evenly spread
      8 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1916 Model
     Breech loading guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 5,153 lbs / 2,337 kg
   Shells per gun, main battery: 100
   4 - 20.0" / 508 mm submerged torpedo tubes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   6.50" / 165 mm   359.51 ft / 109.58 m   10.20 ft / 3.11 m
   Ends:   1.97" / 50 mm   193.57 ft / 59.00 m   10.20 ft / 3.11 m
   Upper:   1.97" / 50 mm   359.51 ft / 109.58 m   8.01 ft / 2.44 m
     Main Belt covers 100 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   6.50" / 165 mm   4.72" / 120 mm      6.50" / 165 mm
   2nd:   0.98" / 25 mm         -               -
   3rd:   0.98" / 25 mm         -               -
   4th:   0.98" / 25 mm         -               -

   - Armour deck: 2.95" / 75 mm, Conning tower: 6.50" / 165 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 80,000 shp / 59,680 Kw = 28.25 kts
   Range 25,000nm at 10.00 kts
   Bunker at max displacement = 4,923 tons

Complement:
   776 - 1,010

Cost:
   £2.453 million / $9.813 million

Distribution of weights at normal displacement:
   Armament: 644 tons, 3.6 %
   Armour: 4,052 tons, 22.5 %
      - Belts: 1,406 tons, 7.8 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 1,028 tons, 5.7 %
      - Armour Deck: 1,522 tons, 8.5 %
      - Conning Tower: 96 tons, 0.5 %
   Machinery: 3,190 tons, 17.7 %
   Hull, fittings & equipment: 6,230 tons, 34.6 %
   Fuel, ammunition & stores: 3,395 tons, 18.8 %
   Miscellaneous weights: 500 tons, 2.8 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     20,175 lbs / 9,151 Kg = 42.3 x 9.8 " / 250 mm shells or 2.1 torpedoes
   Stability (Unstable if below 1.00): 1.08
   Metacentric height 3.5 ft / 1.1 m
   Roll period: 16.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.76
   Seaboat quality  (Average = 1.00): 1.11

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.550
   Length to Beam Ratio: 7.66 : 1
   'Natural speed' for length: 23.52 kts
   Power going to wave formation at top speed: 58 %
   Trim (Max stability = 0, Max steadiness = 100): 45
   Bow angle (Positive = bow angles forward): 10.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      26.25 ft / 8.00 m
      - Forecastle (20 %):   25.43 ft / 7.75 m
      - Mid (50 %):      23.79 ft / 7.25 m (20.51 ft / 6.25 m aft of break)
      - Quarterdeck (15 %):   19.69 ft / 6.00 m
      - Stern:      19.69 ft / 6.00 m
      - Average freeboard:   22.52 ft / 6.86 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 91.4 %
      - Above water (accommodation/working, high = better): 151.7 %
   Waterplane Area: 27,862 Square feet or 2,588 Square metres
   Displacement factor (Displacement / loading): 112 %
   Structure weight / hull surface area: 137 lbs/sq ft or 670 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.92
      - Longitudinal: 2.04
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is excellent

Range @ 12 knots 17,000 nm
Range @ 15 knots 10,200 nm
Range @ 20 knots 4,900 nm
Range @ 28.25 knots 1,840 nm