Imperial Roman Navy: 1915-1919 Designs

[Kaiser Kirk]

40mm would be reasonable for the period, and should perform ok.
Depth is a big issue in TDS design, Snip has 6.5m, or 3.25m/side, which is ok for 1914.

That's the thickness the Germans went with after caisson tests,
they divided the TDS into a simple liquid and Void (or coal and void) with a non-armor steel bulkhead,
and then used a single 40mm armor steel sheet internally.

The alternative the French used for the same purpose was 2 x 19mm laminated together.
That way the combined thickness was about the same as the 40mm for splinters,
but the two sheets could stretch and expand in front of an explosion together.
18-19mm must have been about optimum for that with STS steel as you see the
same odd widths used in USN subpartitions, in front of the bulkhead.

The Germans also had an external hull blister (internally subdivided)* of only 9mm, which the English at Skapa noted was awful thin.
The thin blister would not be able to generate sufficiently large splinters to pose an issue,
the void would decouple the shock wave, and then the liquid would take the remaining shockwave and distribute it evenly
over the armored bulkhead. The bulkhead would then both hold the explosion and be thick enough to stop
any potential splinters.

Getting accurate numbers for use of high tensile strength armor steels vs. mild hull steel in TDS systems (or even decks)
is difficult, many sources treat all the steel the same, and it's really not.

But I digress...
*I think I was mixing navies, the Germans had a thin outer hull....

[snip]

Played around with armor a little bit. Only a 70mm deck is needed for the largest guns in terms of splinter protection and its good enough after that to keep quite a few things within current FC ranges. Made the belt more able to resist the Aztec 280L50, which would be what this ship's armor would be expected to handle. Should give her immunity to those weapons from about 10500m out.

Tullius Leofric, Imperial Roman Republic Large Armored Cruiser laid down 1916

Displacement:
   39,000 t light; 40,884 t standard; 43,734 t normal; 46,014 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (803.81 ft / 787.42 ft) x 108.27 ft x (29.53 / 30.80 ft)
   (245.00 m / 240.00 m) x 33.00 m  x (9.00 / 9.39 m)

Armament:
      12 - 13.39" / 340 mm 45.0 cal guns - 1,212.54lbs / 550.00kg shells, 100 per gun
     Breech loading guns in turret on barbette mounts, 1909 Model
     3 x Quad mounts on centreline ends, majority forward
      1 raised mount - superfiring
      20 - 5.51" / 140 mm 55.0 cal guns - 85.98lbs / 39.00kg shells, 200 per gun
     Quick firing guns in casemate mounts, 1909 Model
     20 x Single mounts on sides, evenly spread
      2 - 3.94" / 100 mm 45.0 cal guns - 30.86lbs / 14.00kg shells, 200 per gun
     Anti-air guns in deck and hoist mounts, 1915 Model
     2 x Single mounts on sides amidships
      2 raised mounts
      4 - 1.77" / 45.0 mm 50.0 cal guns - 3.31lbs / 1.50kg shells, 350 per gun
     Anti-air guns in deck mounts, 1911 Model
     4 x Single mounts on sides, evenly spread
      4 raised mounts
      10 - 0.26" / 6.5 mm 110.0 cal guns - 0.01lbs / 0.00kg shells, 15,000 per gun
     Machine guns in deck mounts, 1911 Model
     10 x Single mounts on sides, evenly spread
      Weight of broadside 16,345 lbs / 7,414 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   10.8" / 275 mm   511.81 ft / 156.00 m   18.04 ft / 5.50 m
   Ends:   1.97" / 50 mm   275.59 ft / 84.00 m   9.84 ft / 3.00 m
     Main Belt covers 100 % of normal length

   - Torpedo Bulkhead - Additional damage containing bulkheads:
      1.57" / 40 mm   511.81 ft / 156.00 m   31.17 ft / 9.50 m
   Beam between torpedo bulkheads 86.94 ft / 26.50 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   13.8" / 350 mm   7.09" / 180 mm      11.0" / 280 mm
   2nd:   3.94" / 100 mm   1.97" / 50 mm      3.94" / 100 mm
   3rd:   0.20" / 5 mm         -         0.98" / 25 mm
   4th:   0.20" / 5 mm         -               -

   - Armoured deck - single deck:
   For and Aft decks: 2.76" / 70 mm
   Forecastle: 0.00" / 0 mm  Quarter deck: 1.38" / 35 mm

   - Conning towers: Forward 12.60" / 320 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 4 shafts, 160,000 shp / 119,360 Kw = 30.02 kts
   Range 8,000nm at 14.00 kts
   Bunker at max displacement = 5,130 tons

Complement:
   1,511 - 1,965

Cost:
   £5.997 million / $23.990 million

Distribution of weights at normal displacement:
   Armament: 2,900 tons, 6.6 %
      - Guns: 2,900 tons, 6.6 %
   Armour: 11,399 tons, 26.1 %
      - Belts: 4,491 tons, 10.3 %
      - Torpedo bulkhead: 929 tons, 2.1 %
      - Armament: 2,857 tons, 6.5 %
      - Armour Deck: 2,785 tons, 6.4 %
      - Conning Tower: 337 tons, 0.8 %
   Machinery: 5,961 tons, 13.6 %
   Hull, fittings & equipment: 16,299 tons, 37.3 %
   Fuel, ammunition & stores: 4,734 tons, 10.8 %
   Miscellaneous weights: 2,440 tons, 5.6 %
      - Hull below water: 1,650 tons
      - Hull above water: 150 tons
      - On freeboard deck: 600 tons
      - Above deck: 40 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     65,152 lbs / 29,553 Kg = 54.3 x 13.4 " / 340 mm shells or 8.5 torpedoes
   Stability (Unstable if below 1.00): 1.20
   Metacentric height 7.8 ft / 2.4 m
   Roll period: 16.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.66
   Seaboat quality  (Average = 1.00): 1.26

Hull form characteristics:
   Hull has low quarterdeck ,
     a normal bow and a round stern
   Block coefficient (normal/deep): 0.608 / 0.613
   Length to Beam Ratio: 7.27 : 1
   'Natural speed' for length: 28.06 kts
   Power going to wave formation at top speed: 53 %
   Trim (Max stability = 0, Max steadiness = 100): 56
   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:   20.00 %,  29.53 ft / 9.00 m,  28.71 ft / 8.75 m
      - Forward deck:   30.00 %,  28.71 ft / 8.75 m,  28.71 ft / 8.75 m
      - Aft deck:   35.00 %,  28.71 ft / 8.75 m,  28.71 ft / 8.75 m
      - Quarter deck:   15.00 %,  19.69 ft / 6.00 m,  19.69 ft / 6.00 m
      - Average freeboard:      27.42 ft / 8.36 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 99.2 %
      - Above water (accommodation/working, high = better): 227.4 %
   Waterplane Area: 62,824 Square feet or 5,837 Square metres
   Displacement factor (Displacement / loading): 110 %
   Structure weight / hull surface area: 198 lbs/sq ft or 967 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.96
      - Longitudinal: 1.44
      - Overall: 1.00
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

[Jefgte]

39000 t & 30 kts ... I will not build the QE class but the Hood class.

[snip]

Some tinkering with the repair schedule and the realization that I get 1913 torps with the heavier 530mm option in 1916 means the Rainier Marion's are likely to be pushed back. This does let me get away with giving them some slightly longer legs and additional room to grow in the future, in addition to the nastier fish.

Rainier Marion, Imperial Roman Destroyer laid down 1916

Displacement:
   1,500 t light; 1,566 t standard; 1,802 t normal; 1,991 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (347.76 ft / 344.49 ft) x 32.81 ft x (11.48 / 12.37 ft)
   (106.00 m / 105.00 m) x 10.00 m  x (3.50 / 3.77 m)

Armament:
      4 - 5.51" / 140 mm 55.0 cal guns - 90.37lbs / 40.99kg shells, 150 per gun
     Quick firing guns in deck mounts, 1916 Model
     4 x Single mounts on centreline ends, evenly spread
      2 raised mounts - superfiring
      4 - 0.26" / 6.5 mm 110.0 cal guns - 0.01lbs / 0.00kg shells, 10,000 per gun
     Machine guns in deck mounts, 1916 Model
     4 x Single mounts on sides, evenly spread
      4 raised mounts
      Weight of broadside 362 lbs / 164 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.39" / 10 mm   0.20" / 5 mm            -
   2nd:   0.20" / 5 mm         -               -

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 32,000 shp / 23,872 Kw = 30.89 kts
   Range 4,650nm at 14.00 kts
   Bunker at max displacement = 424 tons

Complement:
   137 - 179

Cost:
   £0.333 million / $1.333 million

Distribution of weights at normal displacement:
   Armament: 76 tons, 4.2 %
      - Guns: 76 tons, 4.2 %
   Armour: 9 tons, 0.5 %
      - Armament: 9 tons, 0.5 %
   Machinery: 930 tons, 51.6 %
   Hull, fittings & equipment: 420 tons, 23.3 %
   Fuel, ammunition & stores: 302 tons, 16.8 %
   Miscellaneous weights: 65 tons, 3.6 %
      - On freeboard deck: 65 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     498 lbs / 226 Kg = 5.9 x 5.5 " / 140 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.28
   Metacentric height 1.5 ft / 0.4 m
   Roll period: 11.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.45
   Seaboat quality  (Average = 1.00): 1.14

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.486 / 0.498
   Length to Beam Ratio: 10.50 : 1
   'Natural speed' for length: 18.56 kts
   Power going to wave formation at top speed: 66 %
   Trim (Max stability = 0, Max steadiness = 100): 61
   Bow angle (Positive = bow angles forward): 12.50 degrees
   Stern overhang: -4.92 ft / -1.50 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  14.76 ft / 4.50 m,  14.76 ft / 4.50 m
      - Forward deck:   30.00 %,  14.76 ft / 4.50 m,  14.76 ft / 4.50 m
      - Aft deck:   35.00 %,  14.76 ft / 4.50 m,  14.76 ft / 4.50 m
      - Quarter deck:   15.00 %,  14.76 ft / 4.50 m,  14.76 ft / 4.50 m
      - Average freeboard:      14.76 ft / 4.50 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 178.0 %
      - Above water (accommodation/working, high = better): 152.6 %
   Waterplane Area: 7,436 Square feet or 691 Square metres
   Displacement factor (Displacement / loading): 68 %
   Structure weight / hull surface area: 32 lbs/sq ft or 154 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.82
      - Overall: 0.57
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

Misc Wieght
--24t 6x530mm Torpedo Tubes (2x3 mounts centerline)
--8t 1912 FC
--25t LR Wireless
--3t Night Fighting Equpment
--5t Construction Reserve

[snip]

Since the IRS Argonauta is in need of a bit of patching up, the idea of giving her a more serious refit while she is already out of service is being explored. Given her performance at Ironclad Bay, its felt that she still has some decent life left in her and its clearly going to take a proper Dreadnaught to run her over. The refit focuses on giving her as much speed as possible, updating her secondary guns, and providing improved horizontal protection. I'm not sure I'm super happy with where its going so far. Thoughts are welcome.

Argonauta, Imperial Roman Republic Armored Cruiser laid down 1905 (Engine 1915)

Displacement:
   14,955 t light; 15,626 t standard; 16,834 t normal; 17,800 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (524.93 ft / 524.93 ft) x 80.38 ft x (26.25 / 27.41 ft)
   (160.00 m / 160.00 m) x 24.50 m  x (8.00 / 8.36 m)

Armament:
      12 - 8.27" / 210 mm 45.0 cal guns - 242.51lbs / 110.00kg shells, 110 per gun
     Breech loading guns in turret on barbette mounts, 1905 Model
     2 x Twin mounts on centreline ends, evenly spread
     4 x Twin mounts on sides, evenly spread
      10 - 5.51" / 140 mm 55.0 cal guns - 85.98lbs / 39.00kg shells, 175 per gun
     Quick firing guns in casemate mounts, 1909 Model
     10 x Single mounts on sides, evenly spread
      10 hull mounts in casemates- Limited use in heavy seas
      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 sides, evenly spread
      8 raised mounts
      2 - 3.94" / 100 mm 45.0 cal guns - 30.86lbs / 14.00kg shells, 150 per gun
     Anti-air guns in deck and hoist mounts, 1915 Model
     2 x Single mounts on sides amidships
      2 raised mounts
      8 - 0.26" / 6.5 mm 110.0 cal guns - 0.01lbs / 0.00kg shells, 15,000 per gun
     Machine guns in deck mounts, 1911 Model
     8 x Single mounts on sides, evenly spread
      8 raised mounts
      Weight of broadside 4,520 lbs / 2,050 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   7.09" / 180 mm   370.51 ft / 112.93 m   18.04 ft / 5.50 m
   Ends:   2.76" / 70 mm   154.43 ft / 47.07 m   9.84 ft / 3.00 m
   Upper:   3.94" / 100 mm   370.51 ft / 112.93 m   9.02 ft / 2.75 m
     Main Belt covers 109 % of normal length

   - Hull void:
      0.59" / 15 mm   369.29 ft / 112.56 m   18.04 ft / 5.50 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   7.09" / 180 mm   4.33" / 110 mm      7.09" / 180 mm
   2nd:   3.94" / 100 mm   1.97" / 50 mm      3.94" / 100 mm
   3rd:   1.97" / 50 mm   0.20" / 5 mm      3.94" / 100 mm
   4th:   0.20" / 5 mm         -         0.98" / 25 mm
   5th:   0.20" / 5 mm         -               -

   - Armoured deck - single deck:
   For and Aft decks: 1.57" / 40 mm
   Forecastle: 0.59" / 15 mm  Quarter deck: 0.59" / 15 mm

   - Conning towers: Forward 7.87" / 200 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 3 shafts, 63,000 shp / 46,998 Kw = 26.66 kts
   Range 5,980nm at 14.00 kts
   Bunker at max displacement = 2,174 tons

Complement:
   738 - 960

Cost:
   £1.320 million / $5.282 million

Distribution of weights at normal displacement:
   Armament: 1,209 tons, 7.2 %
      - Guns: 1,209 tons, 7.2 %
   Armour: 4,828 tons, 28.7 %
      - Belts: 2,726 tons, 16.2 %
      - Void: 146 tons, 0.9 %
      - Armament: 1,074 tons, 6.4 %
      - Armour Deck: 771 tons, 4.6 %
      - Conning Tower: 111 tons, 0.7 %
   Machinery: 2,386 tons, 14.2 %
   Hull, fittings & equipment: 4,892 tons, 29.1 %
   Fuel, ammunition & stores: 1,879 tons, 11.2 %
   Miscellaneous weights: 1,640 tons, 9.7 %
      - Hull below water: 1,000 tons
      - Hull above water: 200 tons
      - On freeboard deck: 400 tons
      - Above deck: 40 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     23,030 lbs / 10,446 Kg = 81.5 x 8.3 " / 210 mm shells or 2.7 torpedoes
   Stability (Unstable if below 1.00): 1.27
   Metacentric height 5.5 ft / 1.7 m
   Roll period: 14.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 51 %
         - Recoil effect (Restricted arc if above 1.00): 0.31
   Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
   Hull has low quarterdeck ,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.532 / 0.539
   Length to Beam Ratio: 6.53 : 1
   'Natural speed' for length: 22.91 kts
   Power going to wave formation at top speed: 57 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   14.71 %,  18.86 ft / 5.75 m,  18.86 ft / 5.75 m
      - Forward deck:   39.00 %,  18.86 ft / 5.75 m,  18.86 ft / 5.75 m
      - Aft deck:   31.58 %,  18.86 ft / 5.75 m,  18.86 ft / 5.75 m
      - Quarter deck:   14.71 %,  9.84 ft / 3.00 m,  9.84 ft / 3.00 m
      - Average freeboard:      17.54 ft / 5.35 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 79.4 %
      - Above water (accommodation/working, high = better): 141.0 %
   Waterplane Area: 28,956 Square feet or 2,690 Square metres
   Displacement factor (Displacement / loading): 108 %
   Structure weight / hull surface area: 133 lbs/sq ft or 651 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.98
      - Longitudinal: 1.67
      - Overall: 1.03
   Excellent machinery, storage, compartmentation space
   Excellent accommodation and workspace room

[Desertfox]

Her speed is just evil... How much is the total cost including repairs?

[The Rock Doctor]

It looks decent to me.  You've got excess hull strength so I'd boost the protection for the foredeck and quarterdeck.

[Kaiser Kirk]

I've done similar explorations with my older ACs and BBs.
General note on costs : I've been winding up with ~80% of the cost in $ but half or less in BP.
Which is about to be worthwhile for me.

On many of them, keeping the reciprocating engines
instead of converting to electric & turbines was worth it
in terms of overall speed - though I was running into
seakeeping issues with high speeds you may not be. 

Overall, the 40mm deck is nice, but not quite thick enough.
The 12" class can be defended against with a 53mm, (coincidentally just about what Royal Navy DNs had)
and the 10" class with 43mm.

I would also raise the QD armor to more than 15mm.

[snip]

So I did some additional fiddleing with the deck...

Argonauta, Imperial Roman Republic Armored Cruiser laid down 1905 (Engine 1915)

Displacement:
   14,955 t light; 15,626 t standard; 16,834 t normal; 17,800 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (524.93 ft / 524.93 ft) x 80.38 ft x (26.25 / 27.41 ft)
   (160.00 m / 160.00 m) x 24.50 m  x (8.00 / 8.36 m)

Armament:
      12 - 8.27" / 210 mm 45.0 cal guns - 242.51lbs / 110.00kg shells, 110 per gun
     Breech loading guns in turret on barbette mounts, 1905 Model
     2 x Twin mounts on centreline ends, evenly spread
     4 x Twin mounts on sides, evenly spread
      10 - 5.51" / 140 mm 55.0 cal guns - 85.98lbs / 39.00kg shells, 175 per gun
     Quick firing guns in casemate mounts, 1909 Model
     10 x Single mounts on sides, evenly spread
      10 hull mounts in casemates- Limited use in heavy seas
      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 sides, evenly spread
      8 raised mounts
      2 - 3.94" / 100 mm 45.0 cal guns - 30.86lbs / 14.00kg shells, 150 per gun
     Anti-air guns in deck and hoist mounts, 1915 Model
     2 x Single mounts on sides amidships
      2 raised mounts
      8 - 0.26" / 6.5 mm 110.0 cal guns - 0.01lbs / 0.00kg shells, 15,000 per gun
     Machine guns in deck mounts, 1911 Model
     8 x Single mounts on sides, evenly spread
      8 raised mounts
      Weight of broadside 4,520 lbs / 2,050 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   7.09" / 180 mm   370.51 ft / 112.93 m   18.04 ft / 5.50 m
   Ends:   2.76" / 70 mm   154.43 ft / 47.07 m   9.84 ft / 3.00 m
   Upper:   3.94" / 100 mm   370.51 ft / 112.93 m   9.02 ft / 2.75 m
     Main Belt covers 109 % of normal length

   - Hull void:
      0.59" / 15 mm   369.29 ft / 112.56 m   18.04 ft / 5.50 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   7.09" / 180 mm   4.33" / 110 mm      7.09" / 180 mm
   2nd:   3.94" / 100 mm   1.97" / 50 mm      3.94" / 100 mm
   3rd:   1.97" / 50 mm   0.20" / 5 mm      3.94" / 100 mm
   4th:   0.20" / 5 mm         -         0.98" / 25 mm
   5th:   0.20" / 5 mm         -               -

   - Armoured deck - single deck:
   For and Aft decks: 2.17" / 55 mm
   Forecastle: 2.17" / 55 mm  Quarter deck: 2.17" / 55 mm

   - Conning towers: Forward 7.87" / 200 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 3 shafts, 63,000 shp / 46,998 Kw = 26.66 kts
   Range 5,980nm at 14.00 kts
   Bunker at max displacement = 2,174 tons

Complement:
   738 - 960

Cost:
   £1.320 million / $5.282 million

Distribution of weights at normal displacement:
   Armament: 1,209 tons, 7.2 %
      - Guns: 1,209 tons, 7.2 %
   Armour: 5,227 tons, 31.1 %
      - Belts: 2,726 tons, 16.2 %
      - Void: 146 tons, 0.9 %
      - Armament: 1,074 tons, 6.4 %
      - Armour Deck: 1,170 tons, 6.9 %
      - Conning Tower: 111 tons, 0.7 %
   Machinery: 2,386 tons, 14.2 %
   Hull, fittings & equipment: 4,693 tons, 27.9 %
   Fuel, ammunition & stores: 1,879 tons, 11.2 %
   Miscellaneous weights: 1,440 tons, 8.6 %
      - Hull below water: 800 tons
      - Hull above water: 200 tons
      - On freeboard deck: 400 tons
      - Above deck: 40 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     23,327 lbs / 10,581 Kg = 82.6 x 8.3 " / 210 mm shells or 2.7 torpedoes
   Stability (Unstable if below 1.00): 1.27
   Metacentric height 5.6 ft / 1.7 m
   Roll period: 14.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.30
   Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
   Hull has low quarterdeck ,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.532 / 0.539
   Length to Beam Ratio: 6.53 : 1
   'Natural speed' for length: 22.91 kts
   Power going to wave formation at top speed: 57 %
   Trim (Max stability = 0, Max steadiness = 100): 49
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   14.71 %,  18.86 ft / 5.75 m,  18.86 ft / 5.75 m
      - Forward deck:   39.00 %,  18.86 ft / 5.75 m,  18.86 ft / 5.75 m
      - Aft deck:   31.58 %,  18.86 ft / 5.75 m,  18.86 ft / 5.75 m
      - Quarter deck:   14.71 %,  9.84 ft / 3.00 m,  9.84 ft / 3.00 m
      - Average freeboard:      17.54 ft / 5.35 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 78.1 %
      - Above water (accommodation/working, high = better): 141.0 %
   Waterplane Area: 28,956 Square feet or 2,690 Square metres
   Displacement factor (Displacement / loading): 106 %
   Structure weight / hull surface area: 129 lbs/sq ft or 628 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.94
      - Longitudinal: 1.61
      - Overall: 1.00
   Excellent machinery, storage, compartmentation space
   Excellent accommodation and workspace room

[TacCovert4]

That deck should work until plunging fire becomes a thing.

[Kaiser Kirk]

That deck should work until plunging fire becomes a thing.

At 15.6k tons standard, hard to fit a 75-100mm deck.
but presumably the Argonautica won't be trying to engage 13"+ dreadnaughts at range :)
But even against 13"+ that's proof at shorter ranges.

[Jefgte]

She is intended to engage its fellows, not battleships.
She is fairly well balanced for 15000t and 1905-1915.
She can be a quick wing for the battle line and engage other cruisers.

[snip]

Revisiting the Heavy Destroyer Leader concept, the alternative design packs 140s, at the expense of a traditional armor layout.

Agincourt, Imperial Roman Republic Heavy Destroyer Leader laid down 1915

Displacement:
   6,000 t light; 6,270 t standard; 7,107 t normal; 7,776 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (492.13 ft / 492.13 ft) x 50.85 ft x (17.22 / 18.53 ft)
   (150.00 m / 150.00 m) x 15.50 m  x (5.25 / 5.65 m)

Armament:
      10 - 5.51" / 140 mm 55.0 cal guns - 85.98lbs / 39.00kg shells, 250 per gun
     Quick firing guns in deck and hoist mounts, 1909 Model
     5 x Twin mounts on centreline, evenly spread
      2 raised mounts
      1 - 3.94" / 100 mm 45.0 cal gun - 30.86lbs / 14.00kg shells, 175 per gun
     Anti-air gun in deck mount, 1915 Model
     1 x Single mount on centreline, aft deck forward
      1 raised mount
      8 - 1.77" / 45.0 mm 50.0 cal guns - 3.31lbs / 1.50kg shells, 350 per gun
     Breech loading guns in deck mounts, 1905 Model
     8 x Single mounts on sides, evenly spread
      8 raised mounts
      8 - 0.26" / 6.5 mm 110.0 cal guns - 0.01lbs / 0.00kg shells, 10,000 per gun
     Machine guns in deck mounts, 1911 Model
     4 x Twin mounts on sides, evenly spread
      4 raised mounts
      Weight of broadside 917 lbs / 416 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.18" / 30 mm   0.39" / 10 mm      1.38" / 35 mm
   2nd:   0.20" / 5 mm         -               -
   3rd:   0.20" / 5 mm   0.12" / 3 mm            -
   4th:   0.12" / 3 mm         -               -

   - Box over machinery & magazines:
   1.18" / 30 mm

   - Conning towers: Forward 2.95" / 75 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 72,000 shp / 53,712 Kw = 31.43 kts
   Range 7,000nm at 14.00 kts
   Bunker at max displacement = 1,506 tons

Complement:
   386 - 503

Cost:
   £1.018 million / $4.072 million

Distribution of weights at normal displacement:
   Armament: 248 tons, 3.5 %
      - Guns: 248 tons, 3.5 %
   Armour: 651 tons, 9.2 %
      - Armament: 29 tons, 0.4 %
      - Armour Deck: 599 tons, 8.4 %
      - Conning Tower: 24 tons, 0.3 %
   Machinery: 2,727 tons, 38.4 %
   Hull, fittings & equipment: 2,193 tons, 30.9 %
   Fuel, ammunition & stores: 1,107 tons, 15.6 %
   Miscellaneous weights: 180 tons, 2.5 %
      - Hull above water: 50 tons
      - On freeboard deck: 100 tons
      - Above deck: 30 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     4,368 lbs / 1,981 Kg = 52.2 x 5.5 " / 140 mm shells or 0.8 torpedoes
   Stability (Unstable if below 1.00): 1.27
   Metacentric height 2.8 ft / 0.9 m
   Roll period: 12.8 seconds
   Steadiness   - As gun platform (Average = 50 %): 54 %
         - Recoil effect (Restricted arc if above 1.00): 0.40
   Seaboat quality  (Average = 1.00): 1.06

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.577 / 0.587
   Length to Beam Ratio: 9.68 : 1
   'Natural speed' for length: 22.18 kts
   Power going to wave formation at top speed: 62 %
   Trim (Max stability = 0, Max steadiness = 100): 51
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  20.51 ft / 6.25 m,  19.69 ft / 6.00 m
      - Forward deck:   30.00 %,  19.69 ft / 6.00 m,  18.86 ft / 5.75 m
      - Aft deck:   35.00 %,  18.86 ft / 5.75 m,  18.86 ft / 5.75 m
      - Quarter deck:   15.00 %,  18.86 ft / 5.75 m,  18.86 ft / 5.75 m
      - Average freeboard:      19.22 ft / 5.86 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 139.6 %
      - Above water (accommodation/working, high = better): 168.4 %
   Waterplane Area: 17,912 Square feet or 1,664 Square metres
   Displacement factor (Displacement / loading): 97 %
   Structure weight / hull surface area: 76 lbs/sq ft or 371 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.84
      - Longitudinal: 1.61
      - Overall: 0.90
   Caution: Hull subject to strain in open-sea
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room

[Desertfox]

No armor! I like it!

I'm not sure the 3mm plate over the MGs is doing anything useful at all, not even as weather shielding.

[snip]

Doing some fiddle with the Tullius Leofric. For 1000t more light I can get the belt up to 320mm. While its still a Large Armored Cruiser in layout, now with more line ship leanings.

Tullius Leofric, Imperial Roman Republic Large Armored Cruiser laid down 1916

Displacement:
   40,000 t light; 41,905 t standard; 44,804 t normal; 47,123 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (803.79 ft / 787.40 ft) x 108.27 ft x (29.53 / 30.80 ft)
   (245.00 m / 240.00 m) x 33.00 m  x (9.00 / 9.39 m)

Armament:
      12 - 13.39" / 340 mm 45.0 cal guns - 1,212.54lbs / 550.00kg shells, 100 per gun
     Breech loading guns in turret on barbette mounts, 1909 Model
     3 x Quad mounts on centreline ends, majority forward
      1 raised mount - superfiring
      20 - 5.51" / 140 mm 55.0 cal guns - 85.98lbs / 39.00kg shells, 200 per gun
     Quick firing guns in casemate mounts, 1909 Model
     20 x Single mounts on sides, evenly spread
      2 - 3.94" / 100 mm 45.0 cal guns - 30.86lbs / 14.00kg shells, 200 per gun
     Anti-air guns in deck and hoist mounts, 1915 Model
     2 x Single mounts on sides amidships
      2 raised mounts
      4 - 1.77" / 45.0 mm 50.0 cal guns - 3.31lbs / 1.50kg shells, 350 per gun
     Anti-air guns in deck mounts, 1911 Model
     4 x Single mounts on sides, evenly spread
      4 raised mounts
      10 - 0.26" / 6.5 mm 110.0 cal guns - 0.01lbs / 0.00kg shells, 15,000 per gun
     Machine guns in deck mounts, 1911 Model
     10 x Single mounts on sides, evenly spread
      Weight of broadside 16,345 lbs / 7,414 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   12.6" / 320 mm   511.81 ft / 156.00 m   18.04 ft / 5.50 m
   Ends:   1.97" / 50 mm   275.59 ft / 84.00 m   9.84 ft / 3.00 m
     Main Belt covers 100 % of normal length

   - Torpedo Bulkhead - Additional damage containing bulkheads:
      1.57" / 40 mm   511.81 ft / 156.00 m   31.17 ft / 9.50 m
   Beam between torpedo bulkheads 86.12 ft / 26.25 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   13.8" / 350 mm   7.09" / 180 mm      11.0" / 280 mm
   2nd:   3.94" / 100 mm   1.97" / 50 mm      3.94" / 100 mm
   3rd:   0.20" / 5 mm         -         0.98" / 25 mm
   4th:   0.20" / 5 mm         -               -

   - Armoured deck - single deck:
   For and Aft decks: 2.76" / 70 mm
   Forecastle: 0.00" / 0 mm  Quarter deck: 1.38" / 35 mm

   - Conning towers: Forward 12.60" / 320 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 4 shafts, 164,000 shp / 122,344 Kw = 30.05 kts
   Range 8,000nm at 14.00 kts
   Bunker at max displacement = 5,218 tons

Complement:
   1,539 - 2,001

Cost:
   £6.089 million / $24.355 million

Distribution of weights at normal displacement:
   Armament: 2,900 tons, 6.5 %
      - Guns: 2,900 tons, 6.5 %
   Armour: 12,153 tons, 27.1 %
      - Belts: 5,201 tons, 11.6 %
      - Torpedo bulkhead: 929 tons, 2.1 %
      - Armament: 2,857 tons, 6.4 %
      - Armour Deck: 2,823 tons, 6.3 %
      - Conning Tower: 342 tons, 0.8 %
   Machinery: 6,110 tons, 13.6 %
   Hull, fittings & equipment: 16,396 tons, 36.6 %
   Fuel, ammunition & stores: 4,804 tons, 10.7 %
   Miscellaneous weights: 2,440 tons, 5.4 %
      - Hull below water: 1,650 tons
      - Hull above water: 150 tons
      - On freeboard deck: 600 tons
      - Above deck: 40 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     67,251 lbs / 30,504 Kg = 56.1 x 13.4 " / 340 mm shells or 8.8 torpedoes
   Stability (Unstable if below 1.00): 1.20
   Metacentric height 7.9 ft / 2.4 m
   Roll period: 16.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.65
   Seaboat quality  (Average = 1.00): 1.24

Hull form characteristics:
   Hull has low quarterdeck ,
     a normal bow and a round stern
   Block coefficient (normal/deep): 0.623 / 0.628
   Length to Beam Ratio: 7.27 : 1
   'Natural speed' for length: 28.06 kts
   Power going to wave formation at top speed: 53 %
   Trim (Max stability = 0, Max steadiness = 100): 56
   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:   20.00 %,  29.53 ft / 9.00 m,  28.71 ft / 8.75 m
      - Forward deck:   30.00 %,  28.71 ft / 8.75 m,  28.71 ft / 8.75 m
      - Aft deck:   35.00 %,  28.71 ft / 8.75 m,  28.71 ft / 8.75 m
      - Quarter deck:   15.00 %,  19.69 ft / 6.00 m,  19.69 ft / 6.00 m
      - Average freeboard:      27.42 ft / 8.36 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 99.1 %
      - Above water (accommodation/working, high = better): 226.3 %
   Waterplane Area: 63,699 Square feet or 5,918 Square metres
   Displacement factor (Displacement / loading): 110 %
   Structure weight / hull surface area: 197 lbs/sq ft or 962 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.96
      - Longitudinal: 1.42
      - Overall: 1.00
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

Aside from the 1000t, this does add an additional turn to the build time, but that helps drop the cost per turn by enough to make it worth looking at.