Imperial Roman Navy: 1926-1930 Designs

[snip]

No idea how I got 57 there, must have fat-fingered something. Revised below, Misc weight adjusted, slightly thickened the Armored Deck and Belt.

AF-28, Imperial Roman Republic Aviation Frigate laid down 1928

Displacement:
   19,000 t light; 19,539 t standard; 21,356 t normal; 22,810 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (705.37 ft / 688.98 ft) x 75.46 ft x (22.97 / 24.27 ft)
   (215.00 m / 210.00 m) x 23.00 m  x (7.00 / 7.40 m)

Armament:
      8 - 5.51" / 140 mm 55.0 cal guns - 85.98lbs / 39.00kg shells, 175 per gun
     Quick firing guns in deck and hoist mounts, 1909 Model
     8 x Single mounts on side ends, evenly spread
      4 - 3.54" / 90.0 mm 50.0 cal guns - 20.94lbs / 9.50kg shells, 250 per gun
     Anti-air guns in deck and hoist mounts, 1926 Model
     2 x Single mounts on sides amidships
      2 raised mounts
     2 x Single mounts on sides amidships
      2 double raised mounts
      16 - 1.10" / 28.0 mm 55.0 cal guns - 0.72lbs / 0.33kg shells, 5,000 per gun
     Anti-air guns in deck mounts, 1926 Model
     4 x Quad mounts on side ends, evenly spread
      10 - 0.30" / 7.5 mm 66.7 cal guns - 0.01lbs / 0.01kg shells, 15,000 per gun
     Machine guns in deck mounts, 1925 Model
     10 x Single mounts on sides, evenly spread
      Weight of broadside 783 lbs / 355 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   3.54" / 90 mm   458.73 ft / 139.82 m   18.04 ft / 5.50 m
   Ends:   Unarmoured
     Main Belt covers 102 % of normal length

   - Torpedo Bulkhead - Additional damage containing bulkheads:
      1.97" / 50 mm   458.73 ft / 139.82 m   29.53 ft / 9.00 m
   Beam between torpedo bulkheads 59.88 ft / 18.25 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.98" / 25 mm   0.59" / 15 mm      1.97" / 50 mm
   2nd:   0.39" / 10 mm   0.20" / 5 mm      0.59" / 15 mm

   - Armoured deck - multiple decks:
   For and Aft decks: 2.17" / 55 mm
   Forecastle: 1.38" / 35 mm  Quarter deck: 1.38" / 35 mm

   - Conning towers: Forward 3.15" / 80 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 4 shafts, 110,000 shp / 82,060 Kw = 30.34 kts
   Range 10,000nm at 14.00 kts
   Bunker at max displacement = 3,271 tons

Complement:
   883 - 1,148

Cost:
   £4.734 million / $18.936 million

Distribution of weights at normal displacement:
   Armament: 270 tons, 1.3 %
      - Guns: 270 tons, 1.3 %
   Armour: 3,776 tons, 17.7 %
      - Belts: 1,221 tons, 5.7 %
      - Torpedo bulkhead: 987 tons, 4.6 %
      - Armament: 47 tons, 0.2 %
      - Armour Deck: 1,470 tons, 6.9 %
      - Conning Tower: 52 tons, 0.2 %
   Machinery: 3,425 tons, 16.0 %
   Hull, fittings & equipment: 6,833 tons, 32.0 %
   Fuel, ammunition & stores: 2,356 tons, 11.0 %
   Miscellaneous weights: 4,696 tons, 22.0 %
      - Hull below water: 2,258 tons
      - Hull above water: 2,258 tons
      - On freeboard deck: 130 tons
      - Above deck: 50 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     39,392 lbs / 17,868 Kg = 470.5 x 5.5 " / 140 mm shells or 5.0 torpedoes
   Stability (Unstable if below 1.00): 1.35
   Metacentric height 5.6 ft / 1.7 m
   Roll period: 13.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.11
   Seaboat quality  (Average = 1.00): 1.96

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a round stern
   Block coefficient (normal/deep): 0.626 / 0.633
   Length to Beam Ratio: 9.13 : 1
   'Natural speed' for length: 26.25 kts
   Power going to wave formation at top speed: 54 %
   Trim (Max stability = 0, Max steadiness = 100): 36
   Bow angle (Positive = bow angles forward): 20.00 degrees
   Stern overhang: 5.64 ft / 1.72 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   16.71 %,  29.53 ft / 9.00 m,  29.53 ft / 9.00 m
      - Forward deck:   30.00 %,  29.53 ft / 9.00 m,  29.53 ft / 9.00 m
      - Aft deck:   36.58 %,  29.53 ft / 9.00 m,  29.53 ft / 9.00 m
      - Quarter deck:   16.71 %,  29.53 ft / 9.00 m,  29.53 ft / 9.00 m
      - Average freeboard:      29.53 ft / 9.00 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 100.8 %
      - Above water (accommodation/working, high = better): 248.1 %
   Waterplane Area: 38,950 Square feet or 3,619 Square metres
   Displacement factor (Displacement / loading): 132 %
   Structure weight / hull surface area: 107 lbs/sq ft or 523 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.93
      - Longitudinal: 1.92
      - Overall: 1.00
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Airgroup of 53 Planes (Pre 1933 tech) [45 Post 1933]
--3619/65 = 56.78 max aircraft pre 1933
--3619/80 = 45.23 max aircraft post 1933

Misc Weight Distribution
-Below Water (2258t)
--2138t Airgroup
--30t Additional Pumps
--60t Improved Damage Control Equipment
--30t Additional Aviation Stores
-Above Water (2258t)
--2138t Airgroup
--25t LR Wireless
--50t Improved Damage Control Equipment
--30t Enhanced Ventilation and Crew Comfort
--5t Cross Hanger Catapult
--5t Floatplane Recovery Equipment
--5t Construction Reserve
-On Deck (150t)
--27t 1918 Fire Control
--50t Enhanced Ventilation and Crew Comfort
--20t Improved Damage Control Equipment
--10t Short Range Wireless
--10t 2x Catapult (Front End of Flightdeck)
--10t Floatplane Recovery Equipment
--3t Construction Reserve
-Above Deck (50t)
--20t Additional Optical Spotting Equipment
--20t Night Fighting Equipment
--5t Improved Signaling Equipment
--5t Smoke Diversion Equipment

[Kaiser Kirk]

Oh I suspect that at one point the draft was a little shallower, or the beam broader, and that caused the waterplane to change a little, moving the calc from 57 to 55. Happens all the time.

I still want the calculation spelled out.
The rest of us should not need to look for the waterplane, and run the numbers
It should be in the notes.

Right now you're budgeting misc weight for 53.45 planes,
for a low, low 124 tons of misc weight you could do 55.

[snip]

I'll edit it back in. The weight budgeted is the most I can do for a post-1933 airgroup, at 3619/80 for 45.2375.

[Kaiser Kirk]

Honestly, I'd trim "Improved Damage Control Equipment", "Enhanced Ventilation and Crew Comfort", SR radios are free for this generation of ship  - though Parthian carriers pay for a 2nd SR radio as a dedicated channel, you have 15t in "5t Floatplane Recovery Equipment" which is optional and built into the cost of floatplanes, I would up night fighting to 25t....but overall you have a great deal of 'storyline' miscellaneous weight. I would think you could find the tonnage there.
Alternately, is there a clear benefit in 30.34 knots vs. 30.25?  You'd save on both engine AND electric drive.

[snip]

Looking at another bigger refit, this time Respublica. The intent here is to retain her as the "fast" capital ship on station in the Carribean for a time while other more modern ships cycle in-and-out of refits or complete construction. Eventually, her fate lies as the Amazon flagship, the investment now is felt to give a modern polish to an old hull that will be good enough while best is acquired.

Respublica (1929), Imperial Roman Large Armored Cruiser laid down 1910 (Engine 1929)

Displacement:
   27,622 t light; 29,028 t standard; 29,765 t normal; 30,355 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (643.36 ft / 629.92 ft) x 91.86 ft x (26.25 / 26.70 ft)
   (196.09 m / 192.00 m) x 28.00 m  x (8.00 / 8.14 m)

Armament:
      9 - 13.39" / 340 mm 45.0 cal guns - 1,450.64lbs / 658.00kg shells, 91 per gun
     Breech loading guns in turret on barbette mounts, 1927 Model
     2 x 3-gun mounts on centreline, forward deck forward
      2 raised mounts - superfiring
     1 x 3-gun mount on centreline, forward deck aft
      12 - 5.51" / 140 mm 55.0 cal guns - 85.98lbs / 39.00kg shells, 175 per gun
     Quick firing guns in deck and hoist mounts, 1909 Model
     6 x Twin mounts on sides, aft evenly spread
      2 raised mounts
      6 - 3.54" / 90.0 mm 50.0 cal guns - 20.94lbs / 9.50kg shells, 250 per gun
     Anti-air guns in deck and hoist mounts, 1926 Model
     4 x Single mounts on sides, aft evenly spread
      4 raised mounts
     2 x Single mounts on sides, forward deck centre
      2 raised mounts
      16 - 1.10" / 28.0 mm 55.0 cal guns - 0.73lbs / 0.33kg shells, 5,000 per gun
     Anti-air guns in deck and hoist mounts, 1926 Model
     2 x Quad mounts on sides, aft deck aft
      2 raised mounts
     2 x Quad mounts on sides, forward deck centre
      2 double raised mounts
      10 - 0.30" / 7.5 mm 66.7 cal guns - 0.01lbs / 0.00kg shells, 15,000 per gun
     Machine guns in deck mounts, 1925 Model
     10 x Single mounts on sides, evenly spread
      10 raised mounts
      Weight of broadside 14,225 lbs / 6,452 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   9.45" / 240 mm   379.72 ft / 115.74 m   16.40 ft / 5.00 m
   Ends:   3.94" / 100 mm   250.20 ft / 76.26 m   9.84 ft / 3.00 m
   Upper:   3.94" / 100 mm   379.72 ft / 115.74 m   9.02 ft / 2.75 m
     Main Belt covers 93 % of normal length

   - Torpedo Bulkhead - Additional damage containing bulkheads:
      1.57" / 40 mm   379.72 ft / 115.74 m   26.25 ft / 8.00 m
   Beam between torpedo bulkheads 83.66 ft / 25.50 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   13.4" / 340 mm   7.09" / 180 mm      11.0" / 280 mm
   2nd:   1.97" / 50 mm   0.59" / 15 mm      3.94" / 100 mm
   3rd:   0.20" / 5 mm         -         0.98" / 25 mm

   - Armoured deck - multiple decks:
   For and Aft decks: 3.94" / 100 mm
   Forecastle: 1.38" / 35 mm  Quarter deck: 1.38" / 35 mm

   - Conning towers: Forward 9.84" / 250 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 4 shafts, 100,000 shp / 74,600 Kw = 27.45 kts
   Range 6,000nm at 10.00 kts
   Bunker at max displacement = 1,326 tons

Complement:
   1,132 - 1,472

Cost:
   £2.556 million / $10.223 million

Distribution of weights at normal displacement:
   Armament: 2,633 tons, 8.8 %
      - Guns: 2,633 tons, 8.8 %
   Armour: 9,343 tons, 31.4 %
      - Belts: 3,566 tons, 12.0 %
      - Torpedo bulkhead: 581 tons, 2.0 %
      - Armament: 2,108 tons, 7.1 %
      - Armour Deck: 2,883 tons, 9.7 %
      - Conning Tower: 204 tons, 0.7 %
   Machinery: 3,071 tons, 10.3 %
   Hull, fittings & equipment: 10,615 tons, 35.7 %
   Fuel, ammunition & stores: 2,143 tons, 7.2 %
   Miscellaneous weights: 1,960 tons, 6.6 %
      - Hull below water: 1,220 tons
      - Hull above water: 210 tons
      - On freeboard deck: 480 tons
      - Above deck: 50 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     39,056 lbs / 17,716 Kg = 32.6 x 13.4 " / 340 mm shells or 5.8 torpedoes
   Stability (Unstable if below 1.00): 1.11
   Metacentric height 5.4 ft / 1.6 m
   Roll period: 16.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.84
   Seaboat quality  (Average = 1.00): 1.00

Hull form characteristics:
   Hull has raised forecastle,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.686 / 0.688
   Length to Beam Ratio: 6.86 : 1
   'Natural speed' for length: 25.10 kts
   Power going to wave formation at top speed: 57 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 20.00 degrees
   Stern overhang: 2.99 ft / 0.91 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   24.72 %,  28.71 ft / 8.75 m,  28.71 ft / 8.75 m
      - Forward deck:   30.00 %,  19.69 ft / 6.00 m,  19.69 ft / 6.00 m
      - Aft deck:   30.28 %,  19.69 ft / 6.00 m,  19.69 ft / 6.00 m
      - Quarter deck:   15.00 %,  19.69 ft / 6.00 m,  19.69 ft / 6.00 m
      - Average freeboard:      21.92 ft / 6.68 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 81.9 %
      - Above water (accommodation/working, high = better): 151.7 %
   Waterplane Area: 45,803 Square feet or 4,255 Square metres
   Displacement factor (Displacement / loading): 105 %
   Structure weight / hull surface area: 188 lbs/sq ft or 919 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.95
      - Longitudinal: 1.61
      - Overall: 1.00
   Excellent machinery, storage, compartmentation space
   Excellent accommodation and workspace room

Misc Distribution
-Below Water (1250t)
--768t Electric Drives
--200t Additional Pumps
--200t Additional Damage Control Equipment
--50t Improved Food & Drink storage
--2t Construction Reserve
-Above Water (210t)
--40t Improved Officer Accommodations
--40t Improved Crew Accommodations
--70t Additional Damage Control Equipment
--20t Enhanced Ventilation and Crew Comfort
--25t Long Range Wireless
--10t Construction Reserve
-On Deck (480t)
--261t 1918 Fire Control
--50t Aviation Facilities (2x Recon Plane & 2x Catapults)
--50t Flag Facilities
--50t Enhanced Ventilation and Crew Comfort
--48t Power Train Assist for 140mm guns
--10t Short Range Wireless
--11t Construction Reserve
-Above Deck (50t)
--25t Night Fighting Equipment
--15t Additional Optical Spotting Equipment
--10t Improved Signaling Equipment

Base Cost: $5.45

Armament: 2633t
2.633 BP / $5.266

New Engines + Electric Drives: 3071t + 768t

3.839 BP / $7.678

New Armored Decks: 2883t

2.883 BP / $2.883

Main Battery Magazine Update to SHS
$0.33

Misc Weight Refresh: 1960t

1.96 BP / $1.96

Total Cost: $23.567 / 11.315
Time: 14.56 Months / 3 Turns

[snip]

Fiddle of something to do with the D-Class Destroyers, now completely obsolete in their design role. The idea is given they are still somewhat fast is to rip all the "big" guns and fish off them, replaced by a massive battery of 57mm guns making them into something heavy to anchor a MTB squadron or provide specialized anti-MTB escort in confined waters.

D-Class (1929), Imperial Roman Republic Light Corvette laid down 1906

Displacement:
   747 t light; 775 t standard; 850 t normal; 910 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (259.20 ft / 252.62 ft) x 26.25 ft x (11.48 / 12.00 ft)
   (79.00 m / 77.00 m) x 8.00 m  x (3.50 / 3.66 m)

Armament:
      10 - 2.24" / 57.0 mm 43.0 cal guns - 5.52lbs / 2.50kg shells, 300 per gun
     Quick firing guns in deck mounts, 1926 Model
     5 x Twin mounts on centreline ends, majority aft
      3 raised mounts - superfiring
      8 - 1.10" / 28.0 mm 55.0 cal guns - 0.72lbs / 0.33kg shells, 250 per gun
     Anti-air guns in deck mounts, 1926 Model
     2 x Quad mounts on sides, aft deck forward
      2 raised mounts
      6 - 0.30" / 7.5 mm 66.7 cal guns - 0.01lbs / 0.01kg shells, 10,000 per gun
     Machine guns in deck mounts, 1925 Model
     6 x Single mounts on sides, aft evenly spread
      Weight of broadside 61 lbs / 28 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.59" / 15 mm   0.39" / 10 mm            -

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 20,000 shp / 14,920 Kw = 29.98 kts
   Range 3,000nm at 10.00 kts
   Bunker at max displacement = 135 tons
     Caution: Delicate, lightweight machinery

Complement:
   78 - 102

Cost:
   £0.100 million / $0.399 million

Distribution of weights at normal displacement:
   Armament: 11 tons, 1.3 %
      - Guns: 11 tons, 1.3 %
   Armour: 11 tons, 1.3 %
      - Armament: 11 tons, 1.3 %
   Machinery: 501 tons, 59.0 %
   Hull, fittings & equipment: 189 tons, 22.2 %
   Fuel, ammunition & stores: 103 tons, 12.1 %
   Miscellaneous weights: 35 tons, 4.1 %
      - On freeboard deck: 35 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     164 lbs / 74 Kg = 29.0 x 2.2 " / 57 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.33
   Metacentric height 1.1 ft / 0.3 m
   Roll period: 10.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 49 %
         - Recoil effect (Restricted arc if above 1.00): 0.11
   Seaboat quality  (Average = 1.00): 0.72

Hull form characteristics:
   Hull has rise forward of midbreak,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.391 / 0.400
   Length to Beam Ratio: 9.63 : 1
   'Natural speed' for length: 15.89 kts
   Power going to wave formation at top speed: 69 %
   Trim (Max stability = 0, Max steadiness = 100): 68
   Bow angle (Positive = bow angles forward): 15.00 degrees
   Stern overhang: 2.40 ft / 0.73 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  15.58 ft / 4.75 m,  15.58 ft / 4.75 m
      - Forward deck:   20.00 %,  15.58 ft / 4.75 m,  15.58 ft / 4.75 m
      - Aft deck:   45.00 %,  6.56 ft / 2.00 m,  6.56 ft / 2.00 m
      - Quarter deck:   15.00 %,  6.56 ft / 2.00 m,  6.56 ft / 2.00 m
      - Average freeboard:      10.17 ft / 3.10 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 195.0 %
      - Above water (accommodation/working, high = better): 92.5 %
   Waterplane Area: 4,057 Square feet or 377 Square metres
   Displacement factor (Displacement / loading): 32 %
   Structure weight / hull surface area: 25 lbs/sq ft or 122 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.62
      - Overall: 0.56
   Cramped machinery, storage, compartmentation space
   Adequate accommodation and workspace room
   Poor seaboat, wet and uncomfortable, reduced performance in heavy weather

Misc would include fire control and night fighting equipment. If this makes sense, I'd look at doing the same to the remaining F-class boats as well.

[Kaiser Kirk]

Interesting concept. Takes the IJN's rotary cannon into a much more updated basis.
The small shell size constrains accuracy, but I would guess the extra ROF makes up for it.
I'll confess that my desire for guns that could hurt a destroyer make me biased against it,
but that's a design choice you're making.
Do you have DP mounts for the 57mm ? 
Would it be worth delaying until you do?

[The Rock Doctor]

I think you'd want a higher magazine capacity for the 57mm guns, perhaps.

[Kaiser Kirk]

I think you'd want a higher magazine capacity for the 57mm guns, perhaps.

The 28mm AAMGs as well.

[TacCovert4]

I concur.  I'm doing 3-400 RPG for my 90 and 120mm offerings, and lighter stuff is getting 1500 RPG if not more....even in the mid 30s the need for a lot of AA shells is apparent.