Small BB

[maddox]

and that's about it.

[maddox]

Oooo, France Pocket Battleship laid down 1920 (Engine 1916)

Displacement:
   15.500 t light; 16.421 t standard; 18.964 t normal; 20.999 t full load

Dimensions: Length overall / water x beam x draught
   557,74 ft / 554,46 ft x 68,90 ft (Bulges 78,74 ft) x 24,61 ft (normal load)
   170,00 m / 169,00 m x 21,00 m (Bulges 24,00 m)  x 7,50 m

Armament:
      6 - 13,39" / 340 mm guns (3x2 guns), 1.366,87lbs / 620,00kg shells, 1914 Model
     Breech loading guns in turrets (on barbettes)
     on centreline, evenly spread
     Aft Main mounts separated by engine room
      8 - 5,51" / 140 mm guns (4x2 guns), 92,59lbs / 42,00kg shells, 1916 Model
     Quick firing guns in deck mounts with hoists
     on side, all amidships, 2 raised mounts - superfiring
      6 - 5,51" / 140 mm guns (3x2 guns), 92,59lbs / 42,00kg shells, 1916 Model
     Quick firing guns in deck mounts with hoists
     on centreline, evenly spread, all raised mounts
      6 - 1,46" / 37,0 mm guns in single mounts, 1,55lbs / 0,70kg shells, 1917 Model
     Anti-aircraft guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 9.507 lbs / 4.312 kg
   Shells per gun, main battery: 100

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   12,0" / 305 mm   304,95 ft / 92,95 m   18,00 ft / 5,49 m
   Ends:   Unarmoured
     Main Belt covers 85% of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   12,0" / 305 mm   9,00" / 229 mm      12,0" / 305 mm
   2nd:   2,00" / 51 mm   1,00" / 25 mm      2,00" / 51 mm
   3rd:   2,00" / 51 mm   1,00" / 25 mm      2,00" / 51 mm
   4th:   0,50" / 13 mm   0,50" / 13 mm            -

   - Armour deck: 3,00" / 76 mm, Conning tower: 6,00" / 152 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 26.792 shp / 19.987 Kw = 21,00 kts
   Range 9.000nm at 16,00 kts
   Bunker at max displacement = 4.578 tons

Complement:
   807 - 1.050

Cost:
   £3,692 million / $14,766 million

Distribution of weights at normal displacement:
   Armament: 1.047 tons, 5,5%
   Armour: 6.235 tons, 32,9%
      - Belts: 2.906 tons, 15,3%
      - Torpedo bulkhead: 0 tons, 0,0%
      - Armament: 1.660 tons, 8,8%
      - Armour Deck: 1.577 tons, 8,3%
      - Conning Tower: 92 tons, 0,5%
   Machinery: 998 tons, 5,3%
   Hull, fittings & equipment: 6.869 tons, 36,2%
   Fuel, ammunition & stores: 3.464 tons, 18,3%
   Miscellaneous weights: 350 tons, 1,8%

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     28.877 lbs / 13.098 Kg = 24,1 x 13,4 " / 340 mm shells or 3,6 torpedoes
   Stability (Unstable if below 1.00): 1,12
   Metacentric height 3,6 ft / 1,1 m
   Roll period: 17,5 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0,88
   Seaboat quality  (Average = 1.00): 1,43

Hull form characteristics:
   Hull has low quarterdeck
   Block coefficient: 0,618
   Length to Beam Ratio: 7,04 : 1
   'Natural speed' for length: 23,55 kts
   Power going to wave formation at top speed: 44 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   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:      19,69 ft / 6,00 m
      - Forecastle (22%):   18,04 ft / 5,50 m
      - Mid (50%):      18,04 ft / 5,50 m
      - Quarterdeck (23%):   9,84 ft / 3,00 m (18,04 ft / 5,50 m before break)
      - Stern:      9,84 ft / 3,00 m
      - Average freeboard:   16,30 ft / 4,97 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 61,5%
      - Above water (accommodation/working, high = better): 121,0%
   Waterplane Area: 28.408 Square feet or 2.639 Square metres
   Displacement factor (Displacement / loading): 112%
   Structure weight / hull surface area: 159 lbs/sq ft or 777 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,96
      - Longitudinal: 1,42
      - 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

350 tons Misc. Weight
250 tons FC
  25 tons ERADe
  25 tons Long Range Marconi
  25 tons Crew Comfort
  25 tons Flag Facilities

[Jefgte]

This one is correct Mario.
Nearly an half BB Richmond Treaty.

I have similar designs in reserve.


Jef

[maddox]

This one is correct Mario.
Nearly an half BB Richmond Treaty.

I have similar designs in reserve.

Jef

Thanks for the confidence.

I see a role for a dozen of these ships.
Station keeping
Port defence
Convoying
Fleshing out Main fleets/screen duty.
Assisting coastal bombardments.

To be honnest. She started as one of Tanthalas's designs, and I mixed in a load of Valeur.
By giving up the heavy secundaries and placing a twin 140mm over each main gun turret,  as well 2 pairs superfiring on the beam next to the forward superstructure/funnel/bridge/Conning tower the secundary broadside is the equal to an Occitanie, 10 on each beam...
The 6 340mm (capable of delivering heavy SAP, HE , Green and Tiamat shells) make this ship a rather hard hitter for her size.

Armor, angled 12" Heroult face hardened plate (KCI) gives her protection the equal of the old 14" Heroult plates. And those are accepted for way bigger Battleships.

[Jefgte]

 

...I see a role for a dozen of these ships.
Station keeping
Port defence
Convoying
Fleshing out Main fleets/screen duty.
Assisting coastal bombardments.
...

& work in the Battleline with 35000t BB too.

They could be useful to have numerical superiority or tactical utility (Jap ACs at Tsushima).


Jef  ;)

[maddox]

Fleshing out Main fleets/screen duty.

& work in the Battleline with 35000t BB too.

Imagine the 2 Occitanies and 3 of those small ones.    That's a 5 BB group.   The opponent will have to make decisions.   Shoot the little ones, and recieve heavy presents from het big ones, or shoot the big ones, and have the little ones step on the toes.

[mentat]

A 2nd Line BB that can really step up to the mark - Tough Little Bu**ers

Trying to go for near perfection - and thinking being slow they will be vulnerable to torpedoing from light forces (despite the very handy14 x 5.5s) - just wondering if there is scope to further toughen them:

- bit addn'l splinter prot'n for Mags?

- any way to sim increased sub-compartmentation?

- increase Stability bit further - more like German WW1 HSF standards?

I think it's a good + versatile design prob. worth investing a bit more - and assuming this needn't bump up costs too much 

I'm thinking Wolverine - no one messes with 'em  ;D

[P3D]

and that's about it.

IOW, now it is not money well spent. 21kts will become 19kts in half a year, meaning a torpedo magnet. Furthermore, the 3m freeboard aft will make the ships usable only in light seas, all the aft would be awash and mounts there unusable if there's any wind.
Combined with tumblehome hull, the ship hardly has any buoyancy reserve - it would be unstable at less than 20* roll angle, then turn over. And that's without any underwater damage. Even nonpenetrating belt hits will cause flooding.

[maddox]

So P3D, what is your real answer to "what is a small BB"?

[Valles]

21kts will become 19kts in half a year,

...um, what?

[eltf177]

I'm thinking a combination of barnicle/algae buildup plus the usual wear-and-tear on the engines, meaning speeds obtained at launching can't be maintained for very long...

[P3D]

So P3D, what is your real answer to "what is a small BB"?

My "small" (or rather, economy) BB is 27000t with 8x16" - i.e. what is being built by Orange.

About what France should build:
Occitanie has 22kts speed - if you want to use a tactically homogeneous battleline they need 22kts speed. Otherwise the extra 1kts on the Occitanie is wasted. I you want to economize further, 20kts is better option with similar speed older BBs around.
Range is too high, 7000@14 should be adequate (would also reduce belt).

Protection:
Increase belt from 12", perhaps reducing depth from 18'. The 3" deck is OK, it needs increase only with hindsight. I think the lack of TDS is false economy, a 200kg torpedo warhead will breach at least one transverse bulkhead, and most probably damage/flood something vital like machinery or magazine.
The main problem is the too low freeboard aft. I'd call 13-14' the minimum for a (not coastal) BB.

Firepower: you need more than two guns able to fire either forward or aft to increase tactical flexibility. The main armament should depend on the opponents it is designed against. Old BBs - 8-9x340, new ones - 2T3x380. Or just a revised Bretagne, 2 of them is more powerful than 3 of these pocket BBs.

[P3D]

Like this,
Bon Marché, laid down 1916

Displacement:
   23,486 t light; 24,931 t standard; 26,758 t normal; 28,220 t full load

Dimensions: Length overall / water x beam x draught
   555.00 ft / 555.00 ft x 94.00 ft x 28.50 ft (normal load)
   169.16 m / 169.16 m x 28.65 m  x 8.69 m

Armament:
      9 - 15.00" / 381 mm guns (3x3 guns), 1,687.50lbs / 765.44kg shells, 1916 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, majority aft, 1 raised mount aft - superfiring
      12 - 5.50" / 140 mm guns (6x2 guns), 83.19lbs / 37.73kg shells, 1916 Model
     Breech loading guns in deck mounts with hoists
     on side, all amidships, 2 raised mounts - superfiring
   Weight of broadside 16,186 lbs / 7,342 kg
   Shells per gun, main battery: 100

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   13.0" / 330 mm   353.00 ft / 107.59 m   12.00 ft / 3.66 m
   Ends:   4.00" / 102 mm   202.00 ft / 61.57 m   12.00 ft / 3.66 m
     Main Belt covers 98 % of normal length

   - Torpedo Bulkhead:
      2.00" / 51 mm   353.00 ft / 107.59 m   29.00 ft / 8.84 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   14.0" / 356 mm   10.0" / 254 mm      13.0" / 330 mm
   3rd:   2.00" / 51 mm   1.00" / 25 mm      1.00" / 25 mm

   - Armour deck: 3.00" / 76 mm, Conning tower: 14.00" / 356 mm

Machinery:
   Oil fired boilers, steam turbines,
   No drive to shaft, 4 shafts, 40,391 shp / 30,131 Kw = 22.00 kts
   Range 7,000nm at 14.00 kts
   Bunker at max displacement = 3,289 tons

Complement:
   1,045 - 1,359

Cost:
   £4.471 million / $17.883 million

Distribution of weights at normal displacement:
   Armament: 2,023 tons, 7.6 %
   Armour: 8,716 tons, 32.6 %
      - Belts: 2,810 tons, 10.5 %
      - Torpedo bulkhead: 758 tons, 2.8 %
      - Armament: 2,701 tons, 10.1 %
      - Armour Deck: 2,177 tons, 8.1 %
      - Conning Tower: 270 tons, 1.0 %
   Machinery: 1,505 tons, 5.6 %
   Hull, fittings & equipment: 10,917 tons, 40.8 %
   Fuel, ammunition & stores: 3,272 tons, 12.2 %
   Miscellaneous weights: 325 tons, 1.2 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     33,061 lbs / 14,996 Kg = 19.6 x 15.0 " / 381 mm shells or 5.4 torpedoes
   Stability (Unstable if below 1.00): 1.10
   Metacentric height 5.5 ft / 1.7 m
   Roll period: 16.9 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.79
   Seaboat quality  (Average = 1.00): 1.22

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.630
   Length to Beam Ratio: 5.90 : 1
   'Natural speed' for length: 23.56 kts
   Power going to wave formation at top speed: 49 %
   Trim (Max stability = 0, Max steadiness = 100): 41
   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:      24.00 ft / 7.32 m
      - Forecastle (22 %):   22.00 ft / 6.71 m
      - Mid (40 %):      22.00 ft / 6.71 m
      - Quarterdeck (15 %):   14.00 ft / 4.27 m
      - Stern:      14.00 ft / 4.27 m
      - Average freeboard:   19.18 ft / 5.84 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 97.1 %
      - Above water (accommodation/working, high = better): 136.9 %
   Waterplane Area: 39,231 Square feet or 3,645 Square metres
   Displacement factor (Displacement / loading): 95 %
   Structure weight / hull surface area: 203 lbs/sq ft or 993 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.94
      - Longitudinal: 1.76
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is excellent
   Good seaboat, rides out heavy weather easily

[Carthaginian]

Not bad, P3D... 'cept she's not going anywhere without any drive system. ;)
A solid little BB that can do fleet ops.

[maddox]

A tad heavier, but better armed.

Cognac, French Battleship laid down 1920 (Engine 1916)

Displacement:
   25.000 t light; 26.774 t standard; 29.336 t normal; 31.385 t full load

Dimensions: Length overall / water x beam x draught
   626,64 ft / 623,36 ft x 88,58 ft (Bulges 104,99 ft) x 26,25 ft (normal load)
   191,00 m / 190,00 m x 27,00 m (Bulges 32,00 m)  x 8,00 m

Armament:
      9 - 14,96" / 380 mm guns (3x3 guns), 1.807,79lbs / 820,00kg shells, 1915 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, majority forward, 1 raised mount - superfiring
      12 - 5,51" / 140 mm guns (6x2 guns), 92,59lbs / 42,00kg shells, 1915 Model
     Breech loading guns in deck mounts with hoists
     on side, all amidships, 2 raised mounts - superfiring
      2 - 5,51" / 140 mm guns (1x2 guns), 92,59lbs / 42,00kg shells, 1920 Model
     Quick firing guns in a deck mount with hoist
     on centreline aft, all raised guns - superfiring
      6 - 1,46" / 37,0 mm guns in single mounts, 1,55lbs / 0,70kg shells, 1920 Model
     Quick firing guns in deck mounts
     on centreline, evenly spread, 2 raised mounts
   Weight of broadside 17.576 lbs / 7.972 kg
   Shells per gun, main battery: 120

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   13,0" / 330 mm   380,25 ft / 115,90 m   14,50 ft / 4,42 m
   Ends:   2,00" / 51 mm   243,09 ft / 74,09 m   11,29 ft / 3,44 m
     Main Belt covers 94% of normal length

   - Torpedo Bulkhead and Bulges:
      2,00" / 51 mm   380,25 ft / 115,90 m   24,73 ft / 7,54 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   13,0" / 330 mm   8,00" / 203 mm      13,0" / 330 mm
   2nd:   2,00" / 51 mm   1,00" / 25 mm      3,00" / 76 mm
   3rd:   2,00" / 51 mm   1,00" / 25 mm      3,00" / 76 mm
   4th:   0,50" / 13 mm   0,50" / 13 mm            -

   - Armour deck: 3,00" / 76 mm, Conning tower: 13,00" / 330 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 41.258 shp / 30.779 Kw = 22,00 kts
   Range 6.800nm at 16,00 kts
   Bunker at max displacement = 4.611 tons

Complement:
   1.120 - 1.457

Cost:
   £6,610 million / $26,439 million

Distribution of weights at normal displacement:
   Armament: 2.031 tons, 6,9%
   Armour: 9.000 tons, 30,7%
      - Belts: 3.349 tons, 11,4%
      - Torpedo bulkhead: 696 tons, 2,4%
      - Armament: 2.452 tons, 8,4%
      - Armour Deck: 2.237 tons, 7,6%
      - Conning Tower: 266 tons, 0,9%
   Machinery: 1.537 tons, 5,2%
   Hull, fittings & equipment: 12.031 tons, 41,0%
   Fuel, ammunition & stores: 4.336 tons, 14,8%
   Miscellaneous weights: 400 tons, 1,4%

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     35.889 lbs / 16.279 Kg = 21,4 x 15,0 " / 380 mm shells or 6,6 torpedoes
   Stability (Unstable if below 1.00): 1,11
   Metacentric height 5,1 ft / 1,6 m
   Roll period: 19,5 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0,60
   Seaboat quality  (Average = 1.00): 1,21

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0,598
   Length to Beam Ratio: 5,94 : 1
   'Natural speed' for length: 24,97 kts
   Power going to wave formation at top speed: 45 %
   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:      26,25 ft / 8,00 m
      - Forecastle (20%):   17,06 ft / 5,20 m
      - Mid (50%):      17,06 ft / 5,20 m
      - Quarterdeck (19%):   16,40 ft / 5,00 m
      - Stern:      16,40 ft / 5,00 m
      - Average freeboard:   17,57 ft / 5,36 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 92,7%
      - Above water (accommodation/working, high = better): 115,8%
   Waterplane Area: 40.301 Square feet or 3.744 Square metres
   Displacement factor (Displacement / loading): 102%
   Structure weight / hull surface area: 209 lbs/sq ft or 1.019 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,98
      - Longitudinal: 1,27
      - 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

250 Ton FC
25 Ton Long Range Marconi
25 Ton ERADe
50 ton Crew Comfort
50 ton not assigned.