Logi's Design Studies

[Tanthalas]

it actualy looks good to me, although for a new build 26 knots might be a tad on the slow side and as always I question the utility of a 20Deg. slope on the main belt (just feals like overkill to me).  However all in all looks like a decent enough ship.

[Logi]

I tried increasing the speed, it killed the armour more than I would like, but its faster...

JunFai, RRC Battlecruiser laid down 1918 (Engine 1916)

Displacement:
   20,000 t light; 21,079 t standard; 22,439 t normal; 23,527 t full load

Dimensions: Length overall / water x beam x draught
   700.00 ft / 690.00 ft x 80.00 ft x 27.00 ft (normal load)
   213.36 m / 210.31 m x 24.38 m  x 8.23 m

Armament:
      8 - 12.00" / 305 mm guns (4x2 guns), 1,040.00lbs / 471.74kg shells, 1918 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      2 - 12.00" / 305 mm guns in single mounts, 1,040.00lbs / 471.74kg shells, 1918 Model
     Breech loading guns in turrets (on barbettes)
     on centreline, all amidships
      16 - 4.13" / 105 mm guns (8x2 guns), 35.32lbs / 16.02kg shells, 1918 Model
     Quick firing guns in deck mounts
     on side, evenly spread
      4 - 2.95" / 75.0 mm guns (2x2 guns), 12.87lbs / 5.84kg shells, 1918 Model
     Anti-aircraft guns in deck mounts
     on centreline, evenly spread
   Weight of broadside 11,017 lbs / 4,997 kg
   Shells per gun, main battery: 100
   9 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   11.0" / 279 mm   416.00 ft / 126.80 m   16.00 ft / 4.88 m
   Ends:   Unarmoured
     Main Belt covers 93 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   11.0" / 279 mm   6.00" / 152 mm      9.00" / 229 mm
   2nd:   11.0" / 279 mm   6.00" / 152 mm      9.00" / 229 mm
   3rd:   1.00" / 25 mm         -               -

   - Armour deck: 2.00" / 51 mm, Conning tower: 3.00" / 76 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 3 shafts, 79,543 shp / 59,339 Kw = 28.00 kts
   Range 8,000nm at 12.00 kts
   Bunker at max displacement = 2,448 tons

Complement:
   916 - 1,191

Cost:
   £4.174 million / $16.695 million

Distribution of weights at normal displacement:
   Armament: 1,157 tons, 5.2 %
   Armour: 6,438 tons, 28.7 %
      - Belts: 3,134 tons, 14.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 1,857 tons, 8.3 %
      - Armour Deck: 1,395 tons, 6.2 %
      - Conning Tower: 51 tons, 0.2 %
   Machinery: 2,964 tons, 13.2 %
   Hull, fittings & equipment: 9,130 tons, 40.7 %
   Fuel, ammunition & stores: 2,439 tons, 10.9 %
   Miscellaneous weights: 312 tons, 1.4 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     24,807 lbs / 11,252 Kg = 28.7 x 12.0 " / 305 mm shells or 2.7 torpedoes
   Stability (Unstable if below 1.00): 1.08
   Metacentric height 4.2 ft / 1.3 m
   Roll period: 16.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.80
   Seaboat quality  (Average = 1.00): 1.00

Hull form characteristics:
   Hull has low quarterdeck
   Block coefficient: 0.527
   Length to Beam Ratio: 8.63 : 1
   'Natural speed' for length: 26.27 kts
   Power going to wave formation at top speed: 48 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 20.00 degrees
   Stern overhang: 2.36 ft / 0.72 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      21.00 ft / 6.40 m
      - Forecastle (20 %):   18.00 ft / 5.49 m
      - Mid (50 %):      16.00 ft / 4.88 m
      - Quarterdeck (15 %):   11.00 ft / 3.35 m (16.00 ft / 4.88 m before break)
      - Stern:      11.00 ft / 3.35 m
      - Average freeboard:   16.19 ft / 4.93 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 83.9 %
      - Above water (accommodation/working, high = better): 114.6 %
   Waterplane Area: 37,703 Square feet or 3,503 Square metres
   Displacement factor (Displacement / loading): 102 %
   Structure weight / hull surface area: 169 lbs/sq ft or 827 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.99
      - Longitudinal: 1.07
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is adequate

[The Rock Doctor]

No torpedo bulkhead?

[Logi]

I would, but that would destroy the belt down to 8". And IMO 8" for a 20k ship is not acceptable, especially if its a BB/BC.

[Borys]

Ahoj!
In such a case I suggest putting aside 0,5$ of your budget for incense sticks.
To burn them to the Gods to make them listen to your prayers of the BC not getting torpedoed ...


Franly, I'd cut down the MG calibre to 11", and invest the savings into the TBS and improving stability.
Borys

[Walter]

Does the changing of the two single 12" turrets to a twin turret free up some hull strength?

[Walter]

Also, in the book Battleships of the Scharnhorst Class by Koop and Schmolke, it says:

In the case of the Scharnhorst class battleships, the narrow 30m beam forced the architects to design the longitudinal torpedo bulkhead at an incline instead of vertically. This was the only way in which it was possible to build in the necessary safety zone between the bulkhead and outer plating.

This ship has a beam that is even narrowed. So, regardless of what SS says and does, does this ship have enough beam for the torpedo protection system to work? If it hasn't, the torpedo bulkhead is just useless extra weight for the ship to drag along.

[Borys]

Ahoj!
Walter, I hadn't looked at the beam. Maybe at 80ft it really isn't worth bothering with ...
Borys

[Jefgte]

... Not sure that the 2 single 12" be useful in a battle.
Are they back to back to fire 160° ?
or twin mount with 120° each side ?

IMO... protect ends & belt protection to 100%.
Seaboat quality & stability could be certainly better with 80.000SHP-28kts.


Jef  ;)

[Logi]

Bah, the singles were a mistype, its supposed to be a twin turret. I'll fix it when I can.

[Jefgte]

Install 12" guns in single mounts could be interresting for coastal ships...


Jef  ;)

[Logi]

Xiamen, RRC Battlecruiser laid down 1918 (Engine 1916)

Displacement:
   19,000 t light; 19,936 t standard; 21,201 t normal; 22,213 t full load

Dimensions: Length overall / water x beam x draught
   557.00 ft / 557.00 ft x 89.30 ft x 30.00 ft (normal load)
   169.77 m / 169.77 m x 27.22 m  x 9.14 m

Armament:
      8 - 11.00" / 279 mm guns (4x2 guns), 865.00lbs / 392.36kg shells, 1918 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      16 - 4.13" / 105 mm guns (8x2 guns), 35.32lbs / 16.02kg shells, 1918 Model
     Quick firing guns in deck mounts with hoists
     on side, all amidships
      4 - 2.95" / 75.0 mm guns (2x2 guns), 12.87lbs / 5.84kg shells, 1918 Model
     Anti-aircraft guns in deck mounts
     on centreline, all amidships, all raised mounts - superfiring
   Weight of broadside 7,537 lbs / 3,419 kg
   Shells per gun, main battery: 120
   6 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   11.0" / 279 mm   363.00 ft / 110.64 m   20.00 ft / 6.10 m
   Ends:   Unarmoured
   Upper:   2.00" / 51 mm   363.00 ft / 110.64 m   9.00 ft / 2.74 m
     Main Belt covers 100 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   12.0" / 305 mm   7.00" / 178 mm      10.0" / 254 mm
   2nd:   2.00" / 51 mm   1.00" / 25 mm            -
   3rd:   0.50" / 13 mm         -               -

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 85,573 shp / 63,838 Kw = 28.00 kts
   Range 8,000nm at 12.00 kts
   Bunker at max displacement = 2,276 tons

Complement:
   878 - 1,142

Cost:
   £3.470 million / $13.881 million

Distribution of weights at normal displacement:
   Armament: 743 tons, 3.5 %
   Armour: 6,793 tons, 32.0 %
      - Belts: 3,756 tons, 17.7 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 1,748 tons, 8.2 %
      - Armour Deck: 1,223 tons, 5.8 %
      - Conning Tower: 66 tons, 0.3 %
   Machinery: 3,188 tons, 15.0 %
   Hull, fittings & equipment: 7,925 tons, 37.4 %
   Fuel, ammunition & stores: 2,201 tons, 10.4 %
   Miscellaneous weights: 350 tons, 1.7 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     27,013 lbs / 12,253 Kg = 40.6 x 11.0 " / 279 mm shells or 3.1 torpedoes
   Stability (Unstable if below 1.00): 1.08
   Metacentric height 4.9 ft / 1.5 m
   Roll period: 16.9 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.53
   Seaboat quality  (Average = 1.00): 1.07

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.497
   Length to Beam Ratio: 6.24 : 1
   'Natural speed' for length: 23.60 kts
   Power going to wave formation at top speed: 58 %
   Trim (Max stability = 0, Max steadiness = 100): 47
   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:      28.00 ft / 8.53 m
      - Forecastle (20 %):   25.00 ft / 7.62 m
      - Mid (50 %):      23.00 ft / 7.01 m (18.00 ft / 5.49 m aft of break)
      - Quarterdeck (15 %):   18.00 ft / 5.49 m
      - Stern:      18.00 ft / 5.49 m
      - Average freeboard:   21.44 ft / 6.53 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 78.3 %
      - Above water (accommodation/working, high = better): 136.6 %
   Waterplane Area: 33,059 Square feet or 3,071 Square metres
   Displacement factor (Displacement / loading): 109 %
   Structure weight / hull surface area: 161 lbs/sq ft or 787 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.91
      - Longitudinal: 2.19
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is excellent

[Logi]

Revisiting the Cruiser Concept.

Hao Class, RRC Protected Cruiser laid down 1919 (Engine 1916)

Displacement:
   7,500 t light; 7,851 t standard; 8,415 t normal; 8,866 t full load

Dimensions: Length overall / water x beam x draught
   557.00 ft / 557.00 ft x 55.70 ft x 20.00 ft (normal load)
   169.77 m / 169.77 m x 16.98 m  x 6.10 m

Armament:
     8 - 7.68" / 195 mm guns (4x2 guns), 226.24lbs / 102.62kg shells, 1919 Model
     Breech loading guns in deck mounts with hoists
     on centreline ends, evenly spread, 2 raised mounts - superfiring
     8 - 4.13" / 105 mm guns (4x2 guns), 35.32lbs / 16.02kg shells, 1919 Model
     Quick firing guns in deck mounts with hoists
     on side, all amidships
     2 - 2.95" / 75.0 mm guns (1x2 guns), 12.87lbs / 5.84kg shells, 1919 Model
     Anti-aircraft guns in deck mount
     on centreline amidships
   Weight of broadside 2,118 lbs / 961 kg
   Shells per gun, main battery: 150
   9 - 21.0" / 533.4 mm above water torpedoes

Armour:
  - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   4.00" / 102 mm   410.00 ft / 124.97 m   15.00 ft / 4.57 m
   Ends:   Unarmoured
     Main Belt covers 113 % of normal length

  - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   4.00" / 102 mm   1.00" / 25 mm      1.00" / 25 mm
   2nd:   2.00" / 51 mm   1.00" / 25 mm      1.00" / 25 mm

  - Armour deck: 1.00" / 25 mm, Conning tower: 3.00" / 76 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 59,272 shp / 44,217 Kw = 30.00 kts
   Range 6,000nm at 12.00 kts
   Bunker at max displacement = 1,015 tons

Complement:
   439 - 571

Cost:
   £1.733 million / $6.930 million

Distribution of weights at normal displacement:
   Armament: 265 tons, 3.1 %
   Armour: 1,523 tons, 18.1 %
      - Belts: 1,004 tons, 11.9 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 119 tons, 1.4 %
      - Armour Deck: 374 tons, 4.4 %
      - Conning Tower: 27 tons, 0.3 %
   Machinery: 2,208 tons, 26.2 %
   Hull, fittings & equipment: 3,270 tons, 38.9 %
   Fuel, ammunition & stores: 915 tons, 10.9 %
   Miscellaneous weights: 233 tons, 2.8 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     7,148 lbs / 3,242 Kg = 31.6 x 7.7 " / 195 mm shells or 1.2 torpedoes
   Stability (Unstable if below 1.00): 1.08
   Metacentric height 2.4 ft / 0.7 m
   Roll period: 15.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.72
   Seaboat quality  (Average = 1.00): 1.08

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.475
   Length to Beam Ratio: 10.00 : 1
   'Natural speed' for length: 23.60 kts
   Power going to wave formation at top speed: 53 %
   Trim (Max stability = 0, Max steadiness = 100): 65
   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:      23.00 ft / 7.01 m
      - Forecastle (20 %):   20.00 ft / 6.10 m
      - Mid (50 %):      18.00 ft / 5.49 m (13.00 ft / 3.96 m aft of break)
      - Quarterdeck (15 %):   13.00 ft / 3.96 m
      - Stern:      13.00 ft / 3.96 m
      - Average freeboard:   16.44 ft / 5.01 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 112.6 %
      - Above water (accommodation/working, high = better): 110.6 %
   Waterplane Area: 20,208 Square feet or 1,877 Square metres
   Displacement factor (Displacement / loading): 101 %
   Structure weight / hull surface area: 101 lbs/sq ft or 495 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.97
      - Longitudinal: 1.25
      - Overall: 1.00
   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

Misc Weight (233t):
100t FCS
25t Radar
25t Long-Range Wireless
54t Torpedoes
29t Construction Reserve

[Borys]

Ahoj!
At first glance I liked it. At second - I deemed concept worthy, but the execution I do not like:
- the MG should be in turrets;
- AD too thin, I'd got for at least 1,5";
- nine TT - is that three mounts? - I believe that a cross-decking mount on such a large ship is problematic;
- I would tinker with stability vs. fireplatform - I'd be happy with 1,10 and 65%;

Borys

[Logi]

1) That would require 250t FCS... And I have a H&M for the 190mm for some reason, so i figure I should use it.
2) I could, that cuts belt height by 3'
3) Yes three mounts. I used the blueprint of Furutaka to place everything. What does "Cross-Decking Mount" mean? :-X
4) Well I aim for 1.08 stability and 70%; so difference of thought there.

I can't add 250t FCS and Turrets without enlarging the ship (and that is not acceptable)

I increased the deck.

Hao Class, RRC Pocket Cruiser laid down 1919 (Engine 1916)

Displacement:
   7,500 t light; 7,851 t standard; 8,415 t normal; 8,866 t full load

Dimensions: Length overall / water x beam x draught
   557.00 ft / 557.00 ft x 55.70 ft x 20.00 ft (normal load)
   169.77 m / 169.77 m x 16.98 m  x 6.10 m

Armament:
      8 - 7.68" / 195 mm guns (4x2 guns), 226.24lbs / 102.62kg shells, 1919 Model
     Breech loading guns in deck mounts with hoists
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      8 - 4.13" / 105 mm guns (4x2 guns), 35.32lbs / 16.02kg shells, 1919 Model
     Quick firing guns in deck mounts with hoists
     on side, all amidships
      2 - 2.95" / 75.0 mm guns (1x2 guns), 12.87lbs / 5.84kg shells, 1919 Model
     Anti-aircraft guns in deck mount
     on centreline amidships
   Weight of broadside 2,118 lbs / 961 kg
   Shells per gun, main battery: 150
   9 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   4.00" / 102 mm   410.00 ft / 124.97 m   12.00 ft / 3.66 m
   Ends:   Unarmoured
     Main Belt covers 113 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   4.00" / 102 mm   1.00" / 25 mm      1.00" / 25 mm
   2nd:   2.00" / 51 mm   1.00" / 25 mm      1.00" / 25 mm

   - Armour deck: 1.50" / 38 mm, Conning tower: 3.00" / 76 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 59,274 shp / 44,219 Kw = 30.00 kts
   Range 6,000nm at 12.00 kts
   Bunker at max displacement = 1,015 tons

Complement:
   439 - 571

Cost:
   £1.733 million / $6.930 million

Distribution of weights at normal displacement:
   Armament: 265 tons, 3.1 %
   Armour: 1,510 tons, 17.9 %
      - Belts: 803 tons, 9.5 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 119 tons, 1.4 %
      - Armour Deck: 561 tons, 6.7 %
      - Conning Tower: 27 tons, 0.3 %
   Machinery: 2,208 tons, 26.2 %
   Hull, fittings & equipment: 3,270 tons, 38.9 %
   Fuel, ammunition & stores: 915 tons, 10.9 %
   Miscellaneous weights: 247 tons, 2.9 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     7,119 lbs / 3,229 Kg = 31.5 x 7.7 " / 195 mm shells or 1.2 torpedoes
   Stability (Unstable if below 1.00): 1.08
   Metacentric height 2.4 ft / 0.7 m
   Roll period: 15.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.72
   Seaboat quality  (Average = 1.00): 1.07

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.475
   Length to Beam Ratio: 10.00 : 1
   'Natural speed' for length: 23.60 kts
   Power going to wave formation at top speed: 53 %
   Trim (Max stability = 0, Max steadiness = 100): 65
   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:      23.00 ft / 7.01 m
      - Forecastle (20 %):   20.00 ft / 6.10 m
      - Mid (50 %):      18.00 ft / 5.49 m (13.00 ft / 3.96 m aft of break)
      - Quarterdeck (15 %):   13.00 ft / 3.96 m
      - Stern:      13.00 ft / 3.96 m
      - Average freeboard:   16.44 ft / 5.01 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 112.7 %
      - Above water (accommodation/working, high = better): 110.6 %
   Waterplane Area: 20,208 Square feet or 1,877 Square metres
   Displacement factor (Displacement / loading): 101 %
   Structure weight / hull surface area: 101 lbs/sq ft or 495 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.97
      - Longitudinal: 1.25
      - Overall: 1.00
   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