Leviathan

[Desertfox]

NS won't go past 16" guns, not because they aren't attractive, but because ships capable of mounting said guns are not very cost effective, or useful to a cruiser navy.

A 24 incher in the guts, is preferable to an 18 incher on deck...

[Valles]

Except that one works at 25,000 yards and the other at only 1,000.

[Walter]

I know what he is thinking. A Long Lance goes a long way. :)

[Valles]

True, in the event that it hits. But they missed pretty much constantly, as I understand it, and for reasons that a sufficiently rigorous course of empirical testing would have predicted.

The Maori, when they were first putting together their destroyer force, outright took their entire fleet out and threw dummy torpedoes at it under every circumstance and doctrinal twist they could think of. Come to think of it, a repeat of that exercise might make an excellent bit of news...

Anyway. The Maori don't bother designing their torpedoes to run for longer than about a minute, because afterwards the target will've moved too much. A gun might be able to afford to spray-and-pray with longer flight times than that, but carrying that many torpedoes would be stupid even if it were possible.

[mentat]

Getting back to guns'n'armour

the 18" on Fuji - was Harvey - easier to make very thick plates - as Hardening is less critical ??

- anyway - less effective than later Krupp Hardened

I think for Krupp Hardened/later - 15" is about the limit for Belt armour - unless get very exorbitant on throwing away sub-standard rejects ! - guess this was the case for Yamato

But - that isn't the limit on overall armour scheme:

  1. De-capping Plate (typically around 1.5") - started being used because 13"+  is very difficult
  2. Backing plate - think Italians did this on Littorio Class
  3. Splinter ptotection inside - esp. for Magazines

so - vs. Belts - potentially lots of reasons for going over 16"

Also - bigger, heavier shells are more accurate and powerful  in plunging fire vs. Decks  ;D

[Kaiser Kirk]

As for max thickness, one book I have claims Duilio- the 1880 4x17.7" Italian turret ship, had 21.5" ...I could swear the maximum I've seen is 24" for a central-battery ship of that period. Thicknesses dropped with Harvey steels introduction.

Over on Wesworld, Red Admiral has repeatedly indicated that somewhere around 350mm was the maximum for a quality face hardened plate in this time frame, larger lost quality fairly fast and were not as effective as could be desired.   I can't vouch for if he's correct, but he usually knows his details.

As for armor schemes.
1. decapping plates did eventually get specified for that purpose on the Littorio class.

The USN used allot of expensive STS - a light armor- in their designs, and specified a plate on the shell plating in the So.Dak and Iowa classes, but did not indicate it was for decapping.

2. Backing plate- the Littorios had a mix of inner screens of various thicknesses, some would have been effective, some not.  I have seen some write ups on the Russian Gangut class, by Italian designers, which indicated there was an interior belt behind the main armor belt. Preston indicates the main belt was thinned by 4 inches and an interior belt 4 inches was provided 11 feet inboard "and above the main belt". Now that last part puzzles me, because it makes no sense, so I wonder if something got garbled.

3. Splinter protection inside was used in varying degrees.

If one feels like if there is some very detailed discussion of how various WWII armor schemes perform here  : http://www.combinedfleet.com/okun_biz.htm
It's a write up of Bismarck's guns vs. various battleships by Nathan Okun. Somewhere in the middle he discusses the Littorio class vs. Bismarck's guns.

[maddox]

From a professional POV, I have to agree with Red Admiral. But adiffer  tad on the thickness.
From my sources and experience with face- and trough hardened steel 380mm is the limit of consistent and economical hardening processes/quality.

[mentat]

KGVs were 15" belt - and i believe there were no problems, but most of the well known expert authors seem to cite 1930s UK Armour as Tops vs. other Countries - even better than US

another key factor against having thicker Belts historically - was the increasing shift of the threat to plunging fire at longer ranges - requiring thicker deck armour - which is very heavy requirement with 100'+ beam

[Kaiser Kirk]

I think it was a combination, as fire control got better, one could expect to engage further out. As a result, while guns got more powerful, they were expected to be defended against further out, so belt thickness did not need to increase. Further, you can introduce a "slope" to your belt via the angle of attack, and gain a slight bit naturally via roll. Decks, there is little you can do to shield except close the range quickly.

As for quality plate sizes, I should have "I think it was" or something. RA could easily had said 15 or 14.5, for some reason 350mm popped into my memory. Or it could be the decline between 350 and 380 is minimal.. dunno.

[Guinness]

350mm is close to 13.5 inches, which certainly was the limit of what was considered feasible for belt armor in the US.

[maddox]

Léviathan design study.

The shellweight was determinating the gunsize. The shells are half again as heavy as the 15" shell used from Superbe to Mont Bruyere.

The anticipated progress on engine weight/size to power ratio is calculated in, as well the maximum thickness of the newly developed Improved Heroult surface hardened armorplate. Belt armor is angled 12°

Bulges were added to increase the stability to counteract the incredible recoil of the main guns.

Paris, French GBB 08 laid down 1922 (Engine 1920)

Displacement:
   43.000 t light; 45.585 t standard; 49.603 t normal; 52.817 t full load

Dimensions: Length overall / water x beam x draught
   790,68 ft / 787,40 ft x 114,83 ft (Bulges 131,23 ft) x 29,53 ft (normal load)
   241,00 m / 240,00 m x 35,00 m (Bulges 40,00 m)  x 9,00 m

Armament:
      8 - 17,72" / 450 mm guns (4x2 guns), 2.711,69lbs / 1.230,00kg shells, 1922 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      20 - 5,51" / 140 mm guns (10x2 guns), 92,59lbs / 42,00kg shells, 1922 Model
     Quick firing guns in deck mounts with hoists
     on side, all amidships, 4 raised mounts - superfiring
      6 - 1,46" / 37,0 mm guns in single mounts, 1,55lbs / 0,70kg shells, 1922 Model
     Anti-aircraft guns in deck mounts
     on centreline, evenly spread, all raised mounts
   Weight of broadside 23.555 lbs / 10.684 kg
   Shells per gun, main battery: 120

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   15,0" / 381 mm   417,32 ft / 127,20 m   19,50 ft / 5,94 m
   Ends:   Unarmoured
     Main Belt covers 82% of normal length

   - Torpedo Bulkhead and Bulges:
      2,00" / 51 mm   417,32 ft / 127,20 m   28,00 ft / 8,53 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   15,0" / 381 mm   12,0" / 305 mm      15,0" / 381 mm
   2nd:   2,00" / 51 mm   1,00" / 25 mm      3,00" / 76 mm
   3rd:   0,50" / 13 mm   0,50" / 13 mm            -

   - Armour deck: 4,00" / 102 mm, Conning tower: 15,00" / 381 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 86.302 shp / 64.382 Kw = 25,00 kts
   Range 9.000nm at 16,00 kts
   Bunker at max displacement = 7.232 tons

Complement:
   1.661 - 2.160

Cost:
   £12,109 million / $48,434 million

Distribution of weights at normal displacement:
   Armament: 2.991 tons, 6,0%
   Armour: 16.098 tons, 32,5%
      - Belts: 5.541 tons, 11,2%
      - Torpedo bulkhead: 865 tons, 1,7%
      - Armament: 4.503 tons, 9,1%
      - Armour Deck: 4.753 tons, 9,6%
      - Conning Tower: 436 tons, 0,9%
   Machinery: 3.018 tons, 6,1%
   Hull, fittings & equipment: 20.294 tons, 40,9%
   Fuel, ammunition & stores: 6.603 tons, 13,3%
   Miscellaneous weights: 600 tons, 1,2%

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     68.872 lbs / 31.240 Kg = 24,8 x 17,7 " / 450 mm shells or 12,4 torpedoes
   Stability (Unstable if below 1.00): 1,14
   Metacentric height 7,8 ft / 2,4 m
   Roll period: 19,7 seconds
   Steadiness   - As gun platform (Average = 50 %): 72 %
         - Recoil effect (Restricted arc if above 1.00): 0,43
   Seaboat quality  (Average = 1.00): 1,22

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0,569
   Length to Beam Ratio: 6,00 : 1
   'Natural speed' for length: 28,06 kts
   Power going to wave formation at top speed: 44 %
   Trim (Max stability = 0, Max steadiness = 100): 59
   Bow angle (Positive = bow angles forward): -5,00 degrees
   Stern overhang: 3,28 ft / 1,00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      32,15 ft / 9,80 m
      - Forecastle (25%):   20,34 ft / 6,20 m
      - Mid (50%):      20,34 ft / 6,20 m
      - Quarterdeck (22%):   20,34 ft / 6,20 m
      - Stern:      20,34 ft / 6,20 m
      - Average freeboard:   21,52 ft / 6,56 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 81,5%
      - Above water (accommodation/working, high = better): 149,8%
   Waterplane Area: 64.236 Square feet or 5.968 Square metres
   Displacement factor (Displacement / loading): 106%
   Structure weight / hull surface area: 231 lbs/sq ft or 1.130 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,99
      - Longitudinal: 1,11
      - Overall: 1,00
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is excellent
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

Misc weight. 
250 ton main gun FC
100 ton secundary FC
50 ton 2* ERADe² installation
50 ton 2* long range marconi
50 ton Admirals quarters
50 ton crew comfort messures
50 ton damage control/Chemical warfare defence.

[ledeper]

I wanna play to: ;D ;D

Enter ship name, Enter country Enter ship type laid down 1922 (Engine 1920)

Displacement:
   56.355 t light; 59.476 t standard; 64.115 t normal; 67.826 t full load

Dimensions: Length overall / water x beam x draught
   858,57 ft / 853,02 ft x 124,67 ft (Bulges 144,36 ft) x 34,45 ft (normal load)
   261,69 m / 260,00 m x 38,00 m (Bulges 44,00 m)  x 10,50 m

Armament:
      9 - 17,72" / 450 mm guns (3x3 guns), 2.780,39lbs / 1.261,17kg shells, 1922 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, majority forward, 1 raised mount - superfiring
      20 - 5,91" / 150 mm guns (10x2 guns), 102,98lbs / 46,71kg shells, 1922 Model
     Quick firing guns in turrets (on barbettes)
     on side, all amidships
      4 - 3,54" / 90,0 mm guns in single mounts, 22,24lbs / 10,09kg shells, 1922 Model
     Anti-aircraft guns in deck mounts
     on side, evenly spread, all raised mounts
      10 - 1,57" / 40,0 mm guns in single mounts, 1,95lbs / 0,89kg shells, 1922 Model
     Breech loading guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 27.192 lbs / 12.334 kg
   Shells per gun, main battery: 120

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   15,7" / 400 mm   482,28 ft / 147,00 m   16,68 ft / 5,08 m
   Ends:   Unarmoured
   Upper:   5,91" / 150 mm   482,28 ft / 147,00 m   8,00 ft / 2,44 m
     Main Belt covers 87 % of normal length

   - Torpedo Bulkhead and Bulges:
      1,97" / 50 mm   482,28 ft / 147,00 m   33,63 ft / 10,25 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   15,7" / 400 mm   11,8" / 300 mm      15,7" / 400 mm
   2nd:   1,97" / 50 mm   0,79" / 20 mm      1,97" / 50 mm
   3rd:   0,79" / 20 mm   0,04" / 1 mm            -

   - Armour deck: 6,69" / 170 mm, Conning tower: 15,75" / 400 mm

Machinery:
   Oil fired boilers, steam turbines plus diesel motors,
   Electric cruising motors plus geared drives, 4 shafts, 170.799 shp / 127.416 Kw = 29,00 kts
   Range 9.000nm at 16,00 kts
   Bunker at max displacement = 8.350 tons

Complement:
   2.013 - 2.618

Cost:
   £15,446 million / $61,785 million

Distribution of weights at normal displacement:
   Armament: 3.399 tons, 5,3 %
   Armour: 21.805 tons, 34,0 %
      - Belts: 6.666 tons, 10,4 %
      - Torpedo bulkhead: 1.181 tons, 1,8 %
      - Armament: 4.403 tons, 6,9 %
      - Armour Deck: 9.011 tons, 14,1 %
      - Conning Tower: 543 tons, 0,8 %
   Machinery: 5.972 tons, 9,3 %
   Hull, fittings & equipment: 24.330 tons, 37,9 %
   Fuel, ammunition & stores: 7.760 tons, 12,1 %
   Miscellaneous weights: 850 tons, 1,3 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     82.875 lbs / 37.592 Kg = 29,8 x 17,7 " / 450 mm shells or 14,4 torpedoes
   Stability (Unstable if below 1.00): 1,29
   Metacentric height 11,0 ft / 3,3 m
   Roll period: 18,3 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0,24
   Seaboat quality  (Average = 1.00): 1,01

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0,529
   Length to Beam Ratio: 5,91 : 1
   'Natural speed' for length: 29,21 kts
   Power going to wave formation at top speed: 50 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   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:      31,50 ft / 9,60 m
      - Forecastle (20 %):   20,05 ft / 6,11 m
      - Mid (50 %):      20,05 ft / 6,11 m
      - Quarterdeck (15 %):   20,05 ft / 6,11 m
      - Stern:      20,05 ft / 6,11 m
      - Average freeboard:   20,96 ft / 6,39 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 86,2 %
      - Above water (accommodation/working, high = better): 138,0 %
   Waterplane Area: 72.776 Square feet or 6.761 Square metres
   Displacement factor (Displacement / loading): 104 %
   Structure weight / hull surface area: 244 lbs/sq ft or 1.190 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,99
      - Longitudinal: 1,09
      - Overall: 1,00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is excellent

[maddox]

Ledeper, you like decks that are "evenly armored"


But, your Biggie would take 5 years and 5 months to build, unless you double the money involved. Then you can reduce that time to 3 years and 10 months.

[ledeper]

Well,here is THE MAXIMUM Bb: :o ::) ::) ;D,it takes only 12 years to build

Enter ship name, Enter country Enter ship type laid down 1930

Displacement:
   147.913 t light; 157.958 t standard; 165.567 t normal; 171.653 t full load

Dimensions: Length overall / water x beam x draught
   1.049,58 ft / 1.044,95 ft x 164,04 ft x 52,49 ft (normal load)
   319,91 m / 318,50 m x 50,00 m  x 16,00 m

Armament:
      8 - 25,00" / 635 mm guns (4x2 guns), 7.812,50lbs / 3.543,69kg shells, 1930 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      20 - 14,96" / 380 mm guns (10x2 guns), 1.674,25lbs / 759,43kg shells, 1930 Model
     Breech loading guns in turrets (on barbettes)
     on side, all amidships
      24 - 5,71" / 145 mm guns (12x2 guns), 93,02lbs / 42,19kg shells, 1930 Model
     Dual purpose guns in deck mounts
     on side, evenly spread, 4 raised mounts
      40 - 1,57" / 40,0 mm guns (20x2 guns), 1,95lbs / 0,89kg shells, 1930 Model
     Breech loading guns in deck mounts
     on side, evenly spread, 5 raised mounts
      60 - 0,79" / 20,0 mm guns (30x2 guns), 0,24lbs / 0,11kg shells, 1930 Model
     Breech loading guns in deck mounts
     on side, evenly spread
   Weight of broadside 98.310 lbs / 44.593 kg
   Shells per gun, main battery: 120

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   19,7" / 500 mm   574,15 ft / 175,00 m   21,46 ft / 6,54 m
   Ends:   Unarmoured
   Upper:   11,8" / 300 mm   574,15 ft / 175,00 m   8,01 ft / 2,44 m
     Main Belt covers 85 % of normal length

   - Torpedo Bulkhead:
      3,94" / 100 mm   574,15 ft / 175,00 m   55,77 ft / 17,00 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   19,7" / 500 mm   13,8" / 350 mm      19,7" / 500 mm
   2nd:   21,7" / 550 mm   9,84" / 250 mm      13,8" / 350 mm
   3rd:   1,97" / 50 mm   0,79" / 20 mm            -
   4th:   0,39" / 10 mm         -               -

   - Armour deck: 13,78" / 350 mm, Conning tower: 19,69" / 500 mm

Machinery:
   Oil fired boilers, steam turbines plus diesel motors,
   Electric cruising motors plus geared drives, 4 shafts, 255.419 shp / 190.543 Kw = 28,00 kts
   Range 9.000nm at 16,00 kts
   Bunker at max displacement = 13.695 tons

Complement:
   4.103 - 5.335

Cost:
   £69,348 million / $277,391 million

Distribution of weights at normal displacement:
   Armament: 12.289 tons, 7,4 %
   Armour: 70.411 tons, 42,5 %
      - Belts: 13.564 tons, 8,2 %
      - Torpedo bulkhead: 4.665 tons, 2,8 %
      - Armament: 17.613 tons, 10,6 %
      - Armour Deck: 33.291 tons, 20,1 %
      - Conning Tower: 1.279 tons, 0,8 %
   Machinery: 7.740 tons, 4,7 %
   Hull, fittings & equipment: 55.974 tons, 33,8 %
   Fuel, ammunition & stores: 17.653 tons, 10,7 %
   Miscellaneous weights: 1.500 tons, 0,9 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     175.309 lbs / 79.519 Kg = 22,4 x 25,0 " / 635 mm shells or 32,3 torpedoes
   Stability (Unstable if below 1.00): 1,05
   Metacentric height 11,5 ft / 3,5 m
   Roll period: 20,3 seconds
   Steadiness   - As gun platform (Average = 50 %): 53 %
         - Recoil effect (Restricted arc if above 1.00): 0,61
   Seaboat quality  (Average = 1.00): 1,07

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0,644
   Length to Beam Ratio: 6,37 : 1
   'Natural speed' for length: 32,33 kts
   Power going to wave formation at top speed: 46 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   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 %):   22,60 ft / 6,89 m
      - Mid (50 %):      22,60 ft / 6,89 m
      - Quarterdeck (15 %):   22,60 ft / 6,89 m
      - Stern:      22,60 ft / 6,89 m
      - Average freeboard:   22,90 ft / 6,98 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 83,0 %
      - Above water (accommodation/working, high = better): 137,0 %
   Waterplane Area: 130.593 Square feet or 12.132 Square metres
   Displacement factor (Displacement / loading): 89 %
   Structure weight / hull surface area: 328 lbs/sq ft or 1.602 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,99
      - Longitudinal: 1,11
      - Overall: 1,00
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is excellent

[TexanCowboy]

Well, ummm....
<sub>GET FRANCE ON THE LINE NOW! WE NEED A RESPONSE!!!

Oh, wait, they have few cruisers.... all is well.  ;D</sub>