Logi's Design Studies

[maddox]

When French ship designers see this ship, they will turn to jelly in shame....  the pure hidiousness is surpassing the French ships by a magnitude.  The RRC designers will get a lot of letters asking how they could be so creative and genial.

[TexanCowboy]

They could have a freeboard of 6 feet. Then it would be even uglier.  ;D

[Logi]

Ok, calculating the belt incline and the space it takes up.

There is roughly a space of 3 feet between the decapping plate and the main belt.
The main belt-inclined at 20 degrees takes a distance of roughly 6 feet.
The main belt itself is roughly 13" (~1.08') horizontally.
The decapping plate itself is roughly 1.33" (~0.11') horizontally.

Add these all together: 10.19' for one side of the ship.
Total space taken by the armour scheme: 20.38'

Subtract that from overall beam: 71.82'
Subtract turret diameter from result: 31.82'

I still have 31.82' to spare; almost 16' on either side.

And I somehow mistaken or overly simplifying this?


And it appears weight savings produce ugly ships. The price for beauty on such a ship is just too high.

Using these numbers:

NORMAL DECAPPING GAP = DGN = 3 - (X - 0.105)(0.111)
where "X" is the thickness of the decapping plate in calibers

14"/45 Four-gun Turret KGV: Inner diameter 40 ft. 0 in.

[Sachmle]

Where's P3D when you need him..this is the kinda stuff he loved.

[The Rock Doctor]

I vaguely recall that there is a rule of thumb, but I can't think of the specifics.

What I do have is the observation about historical practices, from Dunkerque to North Carolina and KGV.  All were wider than 100', and I'm sure there was good reason for it.

[Logi]

Well the recoil effect is still pretty high, although not limiting the ship to end-on-fire. Since both of the ships were able to do a complete broadside, I suppose that may be the reason.

As of now, doing a broadside on my design is a risky maneuver.

Its certainly not about space.

[maddox]

That reason is obvious.  Having a great big hole in the structure of the ship weakens it. Having more than 1 makes it even more weak.

And, of course, not only belt counts, but TB , and that needs room to work. Probably the main weakness of the Iowa's.

[Guinness]

The Dunkerques had a beam of just short of 102 feet, with slight stubby L/B of 6.91.

If you look at line drawings of them though, you'll notice that the main armament wasn't near the widest beam, of course. The beam abreast A turret was probably more like 90 feet, maybe less.

So figure something like 80 feet beam abreast A turret on this design (again give or take). Now I haven't seen the torpedo protection accounted for, but the rule of thumb most of use is 15 feet (or 5ish meters) on either beam. This seems a realistic value from looking at cross sections and schematics of existing ships. This value is more or less the same no matter where in the ship it is measured. So even before anything else, we have to subtract 30 feet total from the ship for the underwater protection. If we figure 80 feet abreast A turret, that leaves only 50. The RN's 14" quads had barbetted diameters of 40 feet, so that means only 5 feet between barbette bottoms and torpedo bulkhead. Very close.

Internal arrangements in that vicinity would be difficult. Structure to hold up those barbettes would be even more difficult. Could it be done? I dunno. Probably given a number of compromises. Would it be worth it to compromise the ship in that way? Probably not.

On top of all that, I agree that recoil of .95 is too high. The easiest way to fix that is beam.

[Logi]

Which would then expand the ship in a type 3 dock. I only have one type 3 dock so it becomes harder to maintain. And adjusting the beam throws a whole of flying dung disks at me. But I'll try to see what I can do.

But I note:
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is adequate

[Sachmle]

You could just be happy w/ 8 guns since she's a smaller ship. 8 14" guns on 24k is pretty good, and she could have some decent armor too.

[Logi]

Bah, this. Much more amour in exchange for a whooping 6700lb main battery firepower.

Juren, RRC Pocket Battleship laid down 1918 (Engine 1916)

Displacement:
   24,500 t light; 25,906 t standard; 27,391 t normal; 28,579 t full load

Dimensions: Length overall / water x beam x draught
   557.00 ft / 552.00 ft x 92.20 ft x 32.00 ft (normal load)
   169.77 m / 168.25 m x 28.10 m  x 9.75 m

Armament:
      8 - 14.00" / 356 mm guns (2x4 guns), 1,650.00lbs / 748.43kg shells, 1918 Model
     Breech loading guns in turrets (on barbettes)
     on centreline, all forward, 1 raised mount - superfiring
      12 - 6.00" / 152 mm guns (6x2 guns), 108.00lbs / 48.99kg shells, 1918 Model
     Breech loading guns in deck mounts
     on side, all amidships
      12 - 4.13" / 105 mm guns (6x2 guns), 35.32lbs / 16.02kg shells, 1918 Model
     Quick firing guns in deck mounts with hoists
     on side, all amidships, all raised mounts - superfiring
      12 - 2.95" / 75.0 mm guns (6x2 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 15,074 lbs / 6,838 kg
   Shells per gun, main battery: 100
   6 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   15.5" / 394 mm   385.00 ft / 117.35 m   17.00 ft / 5.18 m
   Ends:   Unarmoured
     Main Belt covers 107 % of normal length

   - Torpedo Bulkhead:
      2.00" / 51 mm   385.00 ft / 117.35 m   35.00 ft / 10.67 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   14.0" / 356 mm   9.00" / 229 mm      14.0" / 356 mm
   2nd:   2.00" / 51 mm   1.00" / 25 mm            -
   3rd:   1.00" / 25 mm         -         1.00" / 25 mm

   - Armour deck: 4.00" / 102 mm, Conning tower: 14.00" / 356 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 56,548 shp / 42,185 Kw = 24.00 kts
   Range 8,000nm at 12.00 kts
   Bunker at max displacement = 2,673 tons

Complement:
   1,063 - 1,383

Cost:
   £5.004 million / $20.014 million

Distribution of weights at normal displacement:
   Armament: 1,606 tons, 5.9 %
   Armour: 10,261 tons, 37.5 %
      - Belts: 4,394 tons, 16.0 %
      - Torpedo bulkhead: 997 tons, 3.6 %
      - Armament: 1,871 tons, 6.8 %
      - Armour Deck: 2,725 tons, 10.0 %
      - Conning Tower: 274 tons, 1.0 %
   Machinery: 2,107 tons, 7.7 %
   Hull, fittings & equipment: 10,125 tons, 37.0 %
   Fuel, ammunition & stores: 2,891 tons, 10.6 %
   Miscellaneous weights: 401 tons, 1.5 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     32,978 lbs / 14,959 Kg = 24.0 x 14.0 " / 356 mm shells or 5.8 torpedoes
   Stability (Unstable if below 1.00): 1.08
   Metacentric height 5.2 ft / 1.6 m
   Roll period: 17.0 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.71
   Seaboat quality  (Average = 1.00): 1.06

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.589
   Length to Beam Ratio: 5.99 : 1
   'Natural speed' for length: 23.49 kts
   Power going to wave formation at top speed: 54 %
   Trim (Max stability = 0, Max steadiness = 100): 47
   Bow angle (Positive = bow angles forward): 11.30 degrees
   Stern overhang: 1.00 ft / 0.30 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      20.00 ft / 6.10 m
      - Forecastle (20 %):   18.00 ft / 5.49 m
      - Mid (50 %):      17.00 ft / 5.18 m
      - Quarterdeck (10 %):   17.00 ft / 5.18 m
      - Stern:      17.00 ft / 5.18 m
      - Average freeboard:   17.51 ft / 5.34 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 91.3 %
      - Above water (accommodation/working, high = better): 104.4 %
   Waterplane Area: 36,830 Square feet or 3,422 Square metres
   Displacement factor (Displacement / loading): 99 %
   Structure weight / hull surface area: 195 lbs/sq ft or 953 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.92
      - Longitudinal: 2.10
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is adequate

Main Belt is Sloped at 20 Degrees (Internal) - So the vertical length of such a belt is 16 feet
External Vertical Belt  is 1.5" - A Decapping Plate - Noted in SS as upper belt, located in front of Main Belt - thickness is enough to decap projectiles up to 18.6" (WOW)

109 feet : Three guns together (10 ft of space between each gun)
100 feet: Superstructure Length
110 feet: Forecastle
55 feet: Quarterdeck
Total Neccesary Space: 374 feet
Remaining space for Miscellanous: 178 feet

Misc Weights (401t):
250t Primary FCS
25t Long-Range Wireless
25t Radar
24t 21" Torpedoes
25t Extra Pumps
12t Flag Facilities
  5t Climatization
25t Reserve Weight

[Kaiser Kirk]

As for the requisite width for a quad- feel free to use whatever diameter you wish. However, folks are giving you well intentioned advice based on what they know of warship design.

Preston gives the designed beam of Normandie with quad 13.4" as 88 feet 2in. They were canceled later due to lessons learned in WWI. Googling them gets Conways, which does indicate that adding a Torpedo bulge would be needed, but I remain unclear on what their internal TDS situation was.

However, as you've documented, more width would be needed in the case of an internal belt.

However, the follow on Lyon class, also with quad 13.4" ...had a planned beam of 110 feet.  That 22 ft. difference could be for an effective stand off difference on the TDS.

So... I think you're likely missing some necessary structure to support your barbettes, particularly if you are situating them 10 feet apart. Thats 3 real big holes and a great deal of weight on the keel with little in the way of supporting structures.

NORMAL DECAPPING GAP = DGN = 3 - (X - 0.105)(0.111)
where "X" is the thickness of the decapping plate in calibers

14"/45 Four-gun Turret KGV: Inner diameter 40 ft. 0 in.

Currently, in your HY 2, 1917 report, you list no money spent to develop the sloped belt, the capped shell, or the 14" Quad. Since the latter takes 2 years, 1920 is the earliest lay down date unless your report is wrong.

However, I still think it odd to include the decapping plate, and know the precise formula thereoff, as it was something not specified until late 1930s Italian designs, although the outer skin of US vessels was STS of sufficient thickness to act as one in some cases.

In this sim, you can ignore your fellow players advice, as it's up to the Mods to ultimately decide when you push the bounds.  Take historic IJN warships- they pushed the limits....and several had to be brought back to dock for strengthening. Or take the USS North Carolina, with her fine bow forward she was narrow near the forward magazines...which some feel could have been fatal when she was hit by a torpedo, instead she got lucky. Here the presence and extent of such things are up to the mods.

[Logi]

I actually used a 35 ft diameter for the turret in the picture as the gun length isn't all that long and 40 ft would have given it a very short barrel look.

the sloped belt, the capped shell, or the 14"

Actually for the quad, 1 full year of funding and research was put into it, but paused in recent years. So I can have this laid down in 1919.

I'm currently messing by SS trying to keep the weight the same but make the ship larger for a wider beam. You are quite correct, but I think 3 feet is a good estimate.

Consider that in actuality the space given for such a plate was 2 feet, not 3 feet. (The equation also gives 2.7 feet rather than the full 3) I overestimate the space to reflect the lack of real knowledge concerning this.

I see the built ships with quads usually used 105 feet so I'm going to go with that.

[Logi]

Increasing the weight was inevitable, so I increased the weight by 1,500 tons.

As noted in my previous post, the actual gap needed and used OTL was 2', however here it is 3'. A large gap, does not, to my knowledge, change how effective the plate is.

As the beam is also wider with more free space, there is more space for adjusting the decapping gap (which will remain greater than 3 ' no matter what) so while the designers do not know the exact gap distance. They should know a few feet is more than enough.

Juren, RRC Pocket Battleship laid down 1919 (Engine 1916)

Displacement:
   26,000 t light; 27,812 t standard; 29,375 t normal; 30,625 t full load

Dimensions: Length overall / water x beam x draught
   620.00 ft / 612.00 ft x 103.00 ft x 31.00 ft (normal load)
   188.98 m / 186.54 m x 31.39 m  x 9.45 m

Armament:
     12 - 14.00" / 356 mm guns (3x4 guns), 1,650.00lbs / 748.43kg shells, 1919 Model
     Breech loading guns in turrets (on barbettes)
     on centreline, all forward, 1 raised mount - superfiring
     12 - 6.00" / 152 mm guns (6x2 guns), 108.00lbs / 48.99kg shells, 1919 Model
     Breech loading guns in deck mounts
     on side, all amidships
     12 - 4.13" / 105 mm guns (6x2 guns), 35.32lbs / 16.02kg shells, 1919 Model
     Quick firing guns in deck mounts with hoists
     on side, all amidships, all raised mounts - superfiring
     12 - 2.95" / 75.0 mm guns (6x2 guns), 12.87lbs / 5.84kg shells, 1919 Model
     Anti-aircraft guns in deck mounts
     on centreline, all amidships, all raised mounts - superfiring
   Weight of broadside 21,674 lbs / 9,831 kg
   Shells per gun, main battery: 100
   6 - 21.0" / 533.4 mm above water torpedoes

Armour:
  - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   14.5" / 368 mm   400.00 ft / 121.92 m   16.00 ft / 4.88 m
   Ends:   Unarmoured
     Main Belt covers 101 % of normal length

  - Torpedo Bulkhead:
      2.00" / 51 mm   400.00 ft / 121.92 m   33.00 ft / 10.06 m

  - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   12.0" / 305 mm   7.00" / 178 mm      11.0" / 279 mm
   2nd:   2.00" / 51 mm   1.00" / 25 mm            -
   3rd:   1.00" / 25 mm         -         1.00" / 25 mm

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

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 39,936 shp / 29,792 Kw = 22.00 kts
   Range 8,000nm at 12.00 kts
   Bunker at max displacement = 2,814 tons

Complement:
   1,121 - 1,458

Cost:
   £6.641 million / $26.564 million

Distribution of weights at normal displacement:
   Armament: 2,292 tons, 7.8 %
   Armour: 9,465 tons, 32.2 %
      - Belts: 4,063 tons, 13.8 %
      - Torpedo bulkhead: 977 tons, 3.3 %
      - Armament: 1,975 tons, 6.7 %
      - Armour Deck: 2,388 tons, 8.1 %
      - Conning Tower: 62 tons, 0.2 %
   Machinery: 1,488 tons, 5.1 %
   Hull, fittings & equipment: 12,343 tons, 42.0 %
   Fuel, ammunition & stores: 3,375 tons, 11.5 %
   Miscellaneous weights: 411 tons, 1.4 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     32,071 lbs / 14,547 Kg = 23.4 x 14.0 " / 356 mm shells or 5.9 torpedoes
   Stability (Unstable if below 1.00): 1.09
   Metacentric height 6.1 ft / 1.9 m
   Roll period: 17.5 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.70
   Seaboat quality  (Average = 1.00): 1.21

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.526
   Length to Beam Ratio: 5.94 : 1
   'Natural speed' for length: 24.74 kts
   Power going to wave formation at top speed: 44 %
   Trim (Max stability = 0, Max steadiness = 100): 59
   Bow angle (Positive = bow angles forward): 19.45 degrees
   Stern overhang: 2.00 ft / 0.61 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      17.00 ft / 5.18 m
      - Forecastle (15 %):   15.00 ft / 4.57 m
      - Mid (50 %):      15.00 ft / 4.57 m
      - Quarterdeck (10 %):   15.00 ft / 4.57 m
      - Stern:      15.00 ft / 4.57 m
      - Average freeboard:   15.12 ft / 4.61 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 96.0 %
      - Above water (accommodation/working, high = better): 102.5 %
   Waterplane Area: 43,022 Square feet or 3,997 Square metres
   Displacement factor (Displacement / loading): 94 %
   Structure weight / hull surface area: 218 lbs/sq ft or 1,063 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 adequate
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

Main Belt is Sloped at 20 Degrees (Internal) - So the vertical length of such a belt is 15 feet - the main belt is really 13" thick (13.8" Horizontally)
External Vertical Belt  is 1.5" - A Decapping Plate - Noted in SS as part of the main beltupper belt, located in front of Main Belt - thickness is enough to decap projectiles up to 18.6" (but thought to only decap up to 15.5" projectiles by RRC designers)

160 feet : Three guns together (10 ft of space between each gun)
120 feet: Superstructure Length
122.4 feet: Forecastle
61.2  feet: Quarterdeck
Total Neccesary Space: 463.6 feet
Remaining space for Miscellanous: 156.4 feet

Miscellanous space is the space on the other side of the ship. The closer to the space the guns take up, the more center placed the superstructure. In this case, the center of the superstructure  it is only 3.6 feet from the center.

Beam: 103' (~93' at turret's location)
There is roughly a space of 3 feet between the decapping plate and the main belt.
The main belt-inclined at 20 degrees takes a distance of roughly 5.5 feet.
The main belt itself is roughly 13.8" (~1.15') horizontally.
The decapping plate itself is roughly 1.6" (~0.13') horizontally.

Add these all together: 9.78' for one side of the ship.
Total space taken by the armour scheme: 19.56'
Subtract that from overall beam (at turret): 73.44'
Subtract turret diameter from result: 33.44'
Result: 16.72' From either side of the turret to the beam.

The TDS is ~30' wide in total.
Subtract that from overall beam (at turret): 63'
Subtract turret diameter from result: 23'
Result: 11.5' From either side of the turret to the beam.

The conning tower has relatively light armour so as to proof it from splinter fire but to make sure an enemy Battleship shell does not detonate inside the conning tower. The light armour also prevents breaking splinters from a enemy shell passing through and reduces the shock to the conning tower by a shell hit on the tower. This means the electronic systems in the tower are less likely to fail and the conning personnel are less likely to pass out from the shock.

Immunity Zone (to own guns): 6 - 12 -19 Degrees
Immunity Range (to own guns): 10,600 - 18,000 - 24,500 yds

 6 Degrees - The Shell IS Decapped - Penetrates ~13.54" of the Main Belt
12 Degrees - The Shell is NOT Decapped - Penetrates ~3.94" of the Deck
19 Degrees - The Shell IS Decapped - Penetrates ~3.84" of the Deck

Since there is no decapping plate for the deck, I would assume the immunity zone of the ship to its own guns are 10,600 to 18,000 yds - giving the ship 7,400 yds to maneuver against itself.

Misc Weights (411t):
250t Primary FCS
25t Long-Range Wireless
25t Radar
24t 21" Torpedoes
42t Extra Pumps
15t Flag Facilities
 5t Climatization
25t Reserve Weight

[Jefgte]

Nice study & well ballanced BB.

IMO, this is not a Pocket BB, a pocket BB had just 6 main guns.


Jef  ;)