Imperial Roman Navy: 1915-1919 Designs

[snip]

Since looking at cruisers seems to be the favor dejure, I'm toying with follow-ons for the yet-to-be-constructed LRC-15 design from earlier. The difficulties in hand-working the mounts are not going to quite be felt yet, but the impetus to increase the broadside is going to force the main guns into twin turrets rather than additional single gunhouses. The design looses its predecessor's Electric drives due to weight issues surrounding the turrets, but is provided with enough range to match the legs of the heavier machinery. The armor is intended as anti-critical defense as the school of though around cruiser armor is its near impossible to have a design in this size-class well protected against its own guns from a buoyancy standpoint.

GPC-17, Imperial Roman Republic Cruiser laid down 1917

Displacement:
   8,000 t light; 8,309 t standard; 9,356 t normal; 10,194 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (541.34 ft / 541.34 ft) x 57.41 ft x (19.69 / 21.06 ft)
   (165.00 m / 165.00 m) x 17.50 m  x (6.00 / 6.42 m)

Armament:
      6 - 7.09" / 180 mm 50.0 cal guns - 187.39lbs / 85.00kg shells, 150 per gun
     Breech loading guns in turret on barbette mounts, 1915 Model
     3 x 2-gun mounts on centreline ends, majority forward
      1 raised mount - superfiring
      4 - 5.51" / 140 mm 55.0 cal guns - 85.98lbs / 39.00kg shells, 150 per gun
     Breech loading guns in deck mounts, 1909 Model
     4 x Single mounts on sides, aft evenly spread
      Weight of broadside 1,468 lbs / 666 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   1.57" / 40 mm   402.10 ft / 122.56 m   13.12 ft / 4.00 m
   Ends:   0.59" / 15 mm   139.21 ft / 42.43 m   13.12 ft / 4.00 m
     Main Belt covers 114 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   3.94" / 100 mm   0.59" / 15 mm      1.97" / 50 mm

   - Protected deck - single deck:
   For and Aft decks: 2.36" / 60 mm
   Forecastle: 0.79" / 20 mm  Quarter deck: 0.79" / 20 mm

   - Conning towers: Forward 3.94" / 100 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 78,000 shp / 58,188 Kw = 31.21 kts
   Range 8,050nm at 14.00 kts
   Bunker at max displacement = 1,884 tons

Complement:
   475 - 618

Cost:
   £1.490 million / $5.959 million

Distribution of weights at normal displacement:
   Armament: 421 tons, 4.5 %
      - Guns: 421 tons, 4.5 %
   Armour: 1,410 tons, 15.1 %
      - Belts: 376 tons, 4.0 %
      - Armament: 127 tons, 1.4 %
      - Armour Deck: 869 tons, 9.3 %
      - Conning Tower: 38 tons, 0.4 %
   Machinery: 2,859 tons, 30.6 %
   Hull, fittings & equipment: 3,114 tons, 33.3 %
   Fuel, ammunition & stores: 1,356 tons, 14.5 %
   Miscellaneous weights: 195 tons, 2.1 %
      - Hull below water: 70 tons
      - Hull above water: 30 tons
      - On freeboard deck: 75 tons
      - Above deck: 20 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     9,007 lbs / 4,085 Kg = 50.6 x 7.1 " / 180 mm shells or 1.2 torpedoes
   Stability (Unstable if below 1.00): 1.27
   Metacentric height 3.3 ft / 1.0 m
   Roll period: 13.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.36
   Seaboat quality  (Average = 1.00): 1.07

Hull form characteristics:
   Hull has rise forward of midbreak,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.535 / 0.545
   Length to Beam Ratio: 9.43 : 1
   'Natural speed' for length: 23.27 kts
   Power going to wave formation at top speed: 59 %
   Trim (Max stability = 0, Max steadiness = 100): 47
   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:   16.72 %,  25.43 ft / 7.75 m,  25.43 ft / 7.75 m
      - Forward deck:   20.00 %,  25.43 ft / 7.75 m,  25.43 ft / 7.75 m
      - Aft deck:   54.28 %,  16.40 ft / 5.00 m,  16.40 ft / 5.00 m
      - Quarter deck:   9.00 %,  16.40 ft / 5.00 m,  16.40 ft / 5.00 m
      - Average freeboard:      19.72 ft / 6.01 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 114.2 %
      - Above water (accommodation/working, high = better): 161.6 %
   Waterplane Area: 21,394 Square feet or 1,988 Square metres
   Displacement factor (Displacement / loading): 108 %
   Structure weight / hull surface area: 97 lbs/sq ft or 472 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.96
      - Longitudinal: 1.53
      - Overall: 1.00
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room

Still need some tinkering for AA guns and such, but given its a 1917 design a lot can change about those details between now and then.

[snip]

While the Skate type patrol minesweeper proposed was a capable ship, there were concerns about its viability for tasks outside that role due to limited freeboard. The design was also felt to be a little large for its intended role. An alternative proposal immerged as an update to the older Custodi class design.

Custodi IV, Imperial Roman Navy Sloop laid down 1915

Displacement:
   500 t light; 515 t standard; 629 t normal; 720 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (187.00 ft / 183.73 ft) x 26.25 ft x (9.84 / 10.87 ft)
   (57.00 m / 56.00 m) x 8.00 m  x (3.00 / 3.31 m)

Armament:
      1 - 3.94" / 100 mm 45.0 cal gun - 30.86lbs / 14.00kg shells, 75 per gun
     Quick firing gun in deck mount, 1906 Model
     1 x Single mount on centreline, forward deck centre
      2 - 1.77" / 45.0 mm 45.0 cal guns - 3.31lbs / 1.50kg shells, 250 per gun
     Quick firing guns in deck mounts, 1905 Model
     2 x Single mounts on sides, aft deck aft
      4 - 0.26" / 6.5 mm 110.0 cal guns - 0.01lbs / 0.00kg shells, 1,000 per gun
     Machine guns in deck mounts, 1911 Model
     4 x Single mounts on sides, evenly spread
      4 raised mounts
      Weight of broadside 38 lbs / 17 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.59" / 15 mm   0.20" / 5 mm            -
   2nd:   0.20" / 5 mm         -               -
   3rd:   0.20" / 5 mm         -               -

   - Box over machinery & magazines:
   0.39" / 10 mm

Machinery:
   Coal fired boilers, complex reciprocating steam engines,
   Electric motors, 2 shafts, 800 ihp / 597 Kw = 13.48 kts
   Range 5,500nm at 10.00 kts
   Bunker at max displacement = 206 tons (100% coal)

Complement:
   62 - 81

Cost:
   £0.039 million / $0.156 million

Distribution of weights at normal displacement:
   Armament: 7 tons, 1.1 %
      - Guns: 7 tons, 1.1 %
   Armour: 18 tons, 2.9 %
      - Armament: 5 tons, 0.8 %
      - Armour Deck: 13 tons, 2.1 %
   Machinery: 52 tons, 8.3 %
   Hull, fittings & equipment: 172 tons, 27.4 %
   Fuel, ammunition & stores: 129 tons, 20.5 %
   Miscellaneous weights: 250 tons, 39.7 %
      - Hull below water: 75 tons
      - Hull above water: 50 tons
      - On freeboard deck: 110 tons
      - Above deck: 15 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1,424 lbs / 646 Kg = 46.7 x 3.9 " / 100 mm shells or 1.1 torpedoes
   Stability (Unstable if below 1.00): 1.23
   Metacentric height 1.0 ft / 0.3 m
   Roll period: 11.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.07
   Seaboat quality  (Average = 1.00): 1.94

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.464 / 0.481
   Length to Beam Ratio: 7.00 : 1
   'Natural speed' for length: 13.55 kts
   Power going to wave formation at top speed: 43 %
   Trim (Max stability = 0, Max steadiness = 100): 36
   Bow angle (Positive = bow angles forward): 5.00 degrees
   Stern overhang: 2.56 ft / 0.78 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  8.20 ft / 2.50 m,  8.20 ft / 2.50 m
      - Forward deck:   30.00 %,  8.20 ft / 2.50 m,  8.20 ft / 2.50 m
      - Aft deck:   35.00 %,  8.20 ft / 2.50 m,  8.20 ft / 2.50 m
      - Quarter deck:   15.00 %,  8.20 ft / 2.50 m,  8.20 ft / 2.50 m
      - Average freeboard:      8.20 ft / 2.50 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 52.8 %
      - Above water (accommodation/working, high = better): 78.4 %
   Waterplane Area: 3,112 Square feet or 289 Square metres
   Displacement factor (Displacement / loading): 161 %
   Structure weight / hull surface area: 35 lbs/sq ft or 169 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.91
      - Longitudinal: 2.30
      - Overall: 1.00
   Excellent machinery, storage, compartmentation space
   Cramped 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

Misc Distribution
--Below Water (75t)
----13t Electric Drives
----25 Additional Crew Birthing (Aimed to allow for more effective operations over a 24h period with fresh bodies)
----35t Structural Reinforcement (to minimize damage from near-miss explosions)
----2t Construction Reserve
--Above Water (50t)
----25t LR Wireless
----25 Additional Crew Birthing (Aimed to allow for more effective operations over a 24h period with fresh bodies)
--On Deck (110t)
----1t 1912 Fire Control
----50t Minesweeping Equipment
----50t Mines
----9t Construction Reserve
--Above Deck (15t)
----10t Additional Searchlights
----5t Improved Signaling Equipment

The weights shown are for the proposed minesweeping variant.

[snip]

Playing with another cruiser, this one giving up all pretense of being protected for speed. Given its anticipated duty as a trade-protection platform, having the speed to chase down raiders is needed.

GPC-17B, Imperial Roman Republic Cruiser laid down 1917

Displacement:
   9,500 t light; 9,851 t standard; 11,011 t normal; 11,939 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (567.59 ft / 567.59 ft) x 65.62 ft x (19.69 / 20.96 ft)
   (173.00 m / 173.00 m) x 20.00 m  x (6.00 / 6.39 m)

Armament:
      8 - 7.09" / 180 mm 50.0 cal guns - 187.39lbs / 85.00kg shells, 150 per gun
     Breech loading guns in turret on barbette mounts, 1915 Model
     4 x Single mounts on centreline ends, evenly spread
      2 - 3.94" / 100 mm 45.0 cal guns - 30.86lbs / 14.00kg shells, 175 per gun
     Anti-air guns in deck mounts, 1916 Model
     2 x Single mounts on sides, forward deck aft
      6 - 0.26" / 6.5 mm 110.0 cal guns - 0.01lbs / 0.00kg shells, 150 per gun
     Machine guns in deck mounts, 1917 Model
     6 x Single mounts on sides, evenly spread
      6 raised mounts
      Weight of broadside 1,561 lbs / 708 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.97" / 50 mm   0.59" / 15 mm      1.97" / 50 mm
   2nd:   0.20" / 5 mm         -               -
   3rd:   0.20" / 5 mm         -               -

   - Box over machinery & magazines:
   1.97" / 50 mm

   - Conning towers: Forward 2.76" / 70 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 100,000 shp / 74,600 Kw = 32.43 kts
   Range 8,050nm at 14.00 kts
   Bunker at max displacement = 2,088 tons

Complement:
   536 - 698

Cost:
   £1.830 million / $7.319 million

Distribution of weights at normal displacement:
   Armament: 484 tons, 4.4 %
      - Guns: 484 tons, 4.4 %
   Armour: 1,403 tons, 12.7 %
      - Armament: 156 tons, 1.4 %
      - Armour Deck: 1,217 tons, 11.1 %
      - Conning Tower: 29 tons, 0.3 %
   Machinery: 3,666 tons, 33.3 %
   Hull, fittings & equipment: 3,747 tons, 34.0 %
   Fuel, ammunition & stores: 1,511 tons, 13.7 %
   Miscellaneous weights: 200 tons, 1.8 %
      - Hull below water: 70 tons
      - Hull above water: 30 tons
      - On freeboard deck: 80 tons
      - Above deck: 20 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     9,423 lbs / 4,274 Kg = 53.0 x 7.1 " / 180 mm shells or 1.3 torpedoes
   Stability (Unstable if below 1.00): 1.20
   Metacentric height 3.7 ft / 1.1 m
   Roll period: 14.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.31
   Seaboat quality  (Average = 1.00): 1.03

Hull form characteristics:
   Hull has rise forward of midbreak,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.526 / 0.535
   Length to Beam Ratio: 8.65 : 1
   'Natural speed' for length: 23.82 kts
   Power going to wave formation at top speed: 60 %
   Trim (Max stability = 0, Max steadiness = 100): 68
   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 %,  25.43 ft / 7.75 m,  25.43 ft / 7.75 m
      - Forward deck:   30.00 %,  25.43 ft / 7.75 m,  25.43 ft / 7.75 m
      - Aft deck:   35.00 %,  16.40 ft / 5.00 m,  16.40 ft / 5.00 m
      - Quarter deck:   15.00 %,  16.40 ft / 5.00 m,  16.40 ft / 5.00 m
      - Average freeboard:      20.92 ft / 6.38 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 122.4 %
      - Above water (accommodation/working, high = better): 185.7 %
   Waterplane Area: 25,408 Square feet or 2,360 Square metres
   Displacement factor (Displacement / loading): 105 %
   Structure weight / hull surface area: 103 lbs/sq ft or 504 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.95
      - Longitudinal: 1.48
      - Overall: 1.00
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

[Kaiser Kirk]

Playing with another cruiser, this one giving up all pretense of being protected for speed. Given its anticipated duty as a trade-protection platform, having the speed to chase down raiders is needed.

    8 - 7.09" / 180 mm 50.0 cal guns - 187.39lbs / 85.00kg shells, 150 per gun
     Breech loading guns in turret on barbette mounts, 1915 Model
     4 x Single mounts on centreline ends, evenly spread

I think you need to toggle the turrets to twin.

You do like speed.
Still, a very large vessel, with very poor armor.

I tend to look at various ships and wonder how my vessels would fare.
I have 4 'designed' raiding cruisers, 2 of which have 8x 180mm - but in single M&H.
The fastest is 30.25knots, so 2 knots slower.
It has more fuel, and can put holes in your vessel at ranges it can't put holes in mine.
Even the 165mm versions can hole that 50mm at 14,000m.

The other hand is I don't think I'm the OpFor,
so those matchups don't matter to you.

How far can she go at top speed?

[snip]

Switching them to two-gun turrets does not alter the composite at all, good catch.

889nm@32knts for 2,088t bunker

The GPC-17 requirement really is meant as a response to the raiding that has plagued Roman shipping during the war. The Aztec ships doing the raiding are faster than basically every cruiser in my inventory, and just chasing ships like that off is less ideal then sinking them. While the answer ideally would be a 32knt ship armored to resist 180-200mm guns at reasonable ranges, with the guns I have available that means ether something with a huge amount of 180mm guns or a very small amount of 340mm guns (the 210mm being considered obsolete). I can only have so many of those compared to a cruiser like this and war experience has shown I don't have enough hulls as is. The question for right now is more one of starting point, do I begin with something that has a reasonable expectation of protection against smaller guns but is going to get outrun in the medium term (when any faster follow-ups are building) or do I start with speed and accept that the older designs will be very vulnerable to return fire against larger cruiser guns? Ultimately the type will get to a more balanced point as engines get lighter, so its a matter of what will be better utility in the time the ships are the only ones available.

[snip]

Some tweeks to GPC-17A to bring non-primary armament in line with the B variant. Tweeks to armor.

GPC-17A, Imperial Roman Republic Cruiser laid down 1917

Displacement:
   8,000 t light; 8,287 t standard; 9,332 t normal; 10,168 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (541.34 ft / 541.34 ft) x 57.41 ft x (19.69 / 21.05 ft)
   (165.00 m / 165.00 m) x 17.50 m  x (6.00 / 6.42 m)

Armament:
      6 - 7.09" / 180 mm 50.0 cal guns - 187.39lbs / 85.00kg shells, 150 per gun
     Breech loading guns in turret on barbette mounts, 1915 Model
     3 x 2-gun mounts on centreline ends, majority forward
      1 raised mount - superfiring
      2 - 3.94" / 100 mm 45.0 cal guns - 30.77lbs / 13.96kg shells, 175 per gun
     Anti-air guns in deck mounts, 1917 Model
     2 x Single mounts on sides, aft deck centre
      2 raised mounts
      6 - 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
     6 x Single mounts on sides, evenly spread
      6 raised mounts
      Weight of broadside 1,186 lbs / 538 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   1.77" / 45 mm   396.69 ft / 120.91 m   14.76 ft / 4.50 m
   Ends:   0.79" / 20 mm   144.62 ft / 44.08 m   9.84 ft / 3.00 m
     Main Belt covers 113 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.97" / 50 mm   0.59" / 15 mm      1.97" / 50 mm
   2nd:   0.20" / 5 mm         -               -
   3rd:   0.20" / 5 mm         -               -

   - Protected deck - single deck:
   For and Aft decks: 2.36" / 60 mm
   Forecastle: 0.59" / 15 mm  Quarter deck: 1.18" / 30 mm

   - Conning towers: Forward 3.94" / 100 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 78,000 shp / 58,188 Kw = 31.23 kts
   Range 8,050nm at 14.00 kts
   Bunker at max displacement = 1,881 tons

Complement:
   474 - 617

Cost:
   £1.457 million / $5.829 million

Distribution of weights at normal displacement:
   Armament: 366 tons, 3.9 %
      - Guns: 366 tons, 3.9 %
   Armour: 1,491 tons, 16.0 %
      - Belts: 462 tons, 5.0 %
      - Armament: 124 tons, 1.3 %
      - Armour Deck: 867 tons, 9.3 %
      - Conning Tower: 38 tons, 0.4 %
   Machinery: 2,859 tons, 30.6 %
   Hull, fittings & equipment: 3,079 tons, 33.0 %
   Fuel, ammunition & stores: 1,332 tons, 14.3 %
   Miscellaneous weights: 205 tons, 2.2 %
      - Hull below water: 70 tons
      - Hull above water: 30 tons
      - On freeboard deck: 85 tons
      - Above deck: 20 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     9,194 lbs / 4,170 Kg = 51.7 x 7.1 " / 180 mm shells or 1.2 torpedoes
   Stability (Unstable if below 1.00): 1.27
   Metacentric height 3.3 ft / 1.0 m
   Roll period: 13.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.31
   Seaboat quality  (Average = 1.00): 1.07

Hull form characteristics:
   Hull has rise forward of midbreak,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.534 / 0.544
   Length to Beam Ratio: 9.43 : 1
   'Natural speed' for length: 23.27 kts
   Power going to wave formation at top speed: 59 %
   Trim (Max stability = 0, Max steadiness = 100): 47
   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:   16.72 %,  25.43 ft / 7.75 m,  25.43 ft / 7.75 m
      - Forward deck:   20.00 %,  25.43 ft / 7.75 m,  25.43 ft / 7.75 m
      - Aft deck:   53.28 %,  16.40 ft / 5.00 m,  16.40 ft / 5.00 m
      - Quarter deck:   10.00 %,  16.40 ft / 5.00 m,  16.40 ft / 5.00 m
      - Average freeboard:      19.72 ft / 6.01 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 112.7 %
      - Above water (accommodation/working, high = better): 162.0 %
   Waterplane Area: 21,367 Square feet or 1,985 Square metres
   Displacement factor (Displacement / loading): 109 %
   Structure weight / hull surface area: 95 lbs/sq ft or 462 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.95
      - Longitudinal: 1.50
      - Overall: 1.00
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room

Quarterdeck armor represents a 15mm thick protected deck and 13t of additional armor for steering equipment

[TacCovert4]

Well, I know that I'm one 'potential opfor', so I can speak to this.

You're gaining 2 knots and some change on my Weapon Class Frigates (Cruising Cruisers) which would be the rough analog to these.  That's pretty well across the board with 2 extra knots on the cruising speed as well (working from memory).  However, as you said, you're (in both variants you just posted) giving up all pretense of armor for that. 

Compared to my surviving 5 cruisers (2 Toucans, 3 SC-1s), both variations of this would kill them quite handily.  You'd potentially get chewed up a bit by extreme range 100mm fire on your one without any belt whatsoever, but you'd reliably kill them.

However, comparing it to the Weapon class, in the words of Drach:  "To be perfectly honest"....I'd gladly accept your pursuit engagement in a 1 on 1, and really probably turn to engage.  Reasons are that while you have 2kts of speed which is strategically important and tactically important if you have an immunity zone or you want to force an engagement or flee....you really don't have any of those working for you.  The Weapon class is comfortably armored against the 150-200 band of guns within a decent chunk of ranges, and there's no range at which you can punch me that I can't punch you....conversely I can punch your armor from pretty much wherever my guns can hit all the way to point blank.  Operationally your requirement is to pursue raiders and bring them down rather than just 'drive off' raiders.....this ship can't hope to survive a 1 on 1 against basically anything in the 150mm-200mm class barring extremes of luck.  I'd even argue to a degree that absent sheer numbers, this ship class couldn't reliably stay combat effective in an engagement long enough to hurt some classes of potential raiders sufficiently to cause them to have to go into drydock.

Thinking towards your concerns, and they're valid, I think you're left with this dichotomy. 

You can either build a really tough cruiser that doesn't necessarily have to even be that big, but keep it in the 26-29kt speed band and it's an excellent escort for fending off raiders. 

Or you can go bigger. 

Another consideration is that if you're planning on being the defender against raiders, your cruisers can get punished and stay at sea.  Go AoN on your armor.  As it stands, 50mm plating is effectively just initiating the fuses on AP shells.  And you're not really worried about speed loss from end belt hits as you can always put into port.

[Kaiser Kirk]

The second ship is much better,
the inclusion of the protective deck behind the belt helps, but with a 45mm belt, why not just go 3.66m high and make it +slope armor for the protective deck.
From Okun's work , 2 separate plates are treated as A*1 + B*0.5, so  I'd calculate 45*.5 + 60*1 = 87mm vs 105 as a simple protected deck.
While that leaves more of your upper hull vulnerable, 45mm won't stop much anyhow.

As for the note "13t of additional armor for steering equipment" ...please no.
I have no clue how thick that is.
Per the updated gun research rules, for shell splinters I divide caliber by 6 and compare that to the armor.
20mm works up to 120mm shells. 30mm up to 180mm shells. 15mm deck doesn't stop much of anything, and can be penetrated at your combat ranges
"13t" ...no idea if that's sufficient or not to stop splinters. I'd guess not.

On penetrations - QF penetrations fall off rapidly at 14000m.  So 50mm armor would likely suffice against 150mm QF, maybe 155mm.
BUT... average visibility in the North Sea is 12000m due to fogs.
Take a look at the Battle of the Falklands, despite the Invincibles speed advantage and attempt to keep the range long, range still came down to 8000m, and Scharnhorts landed a 210mm shell in a coal bunker... one fun 'what if' is ...what if that went off, Invincible was seriously damaged/went down, and the Brits had to reevaluate this large AC concept.

[snip]

Is there a way we can handle doing additional steering gear protections? Jeanne d'Arc has the same...

Toying with a different armor scheme, rather than a protected deck moving to an armored deck allows for the belt to be thickened. Now it should be able to keep its own guns out beyond about 10000m. Little light, but for a 1917 design with a 31knt speed Im not sure there is much room for improvement. Give engine tech a couple years and the armor gets better. I've left the quarterdeck notation for now so I dont forget my intent.

GPC-17C, Imperial Roman Republic Cruiser laid down 1917

Displacement:
   8,000 t light; 8,287 t standard; 9,332 t normal; 10,168 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (541.34 ft / 541.34 ft) x 57.41 ft x (19.69 / 21.05 ft)
   (165.00 m / 165.00 m) x 17.50 m  x (6.00 / 6.42 m)

Armament:
      6 - 7.09" / 180 mm 50.0 cal guns - 187.39lbs / 85.00kg shells, 150 per gun
     Breech loading guns in turret on barbette mounts, 1915 Model
     3 x 2-gun mounts on centreline ends, majority forward
      1 raised mount - superfiring
      2 - 3.94" / 100 mm 45.0 cal guns - 30.78lbs / 13.96kg shells, 175 per gun
     Anti-air guns in deck mounts, 1917 Model
     2 x Single mounts on sides, aft deck centre
      2 raised mounts
      6 - 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
     6 x Single mounts on sides, evenly spread
      6 raised mounts
      Weight of broadside 1,186 lbs / 538 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   3.94" / 100 mm   396.69 ft / 120.91 m   14.76 ft / 4.50 m
   Ends:   Unarmoured
     Main Belt covers 113 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   3.94" / 100 mm   1.57" / 40 mm      2.95" / 75 mm
   2nd:   0.20" / 5 mm         -               -
   3rd:   0.20" / 5 mm         -               -

   - Armoured deck - single deck:
   For and Aft decks: 0.79" / 20 mm
   Forecastle: 0.00" / 0 mm  Quarter deck: 0.39" / 10 mm

   - Conning towers: Forward 3.94" / 100 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 78,000 shp / 58,188 Kw = 31.23 kts
   Range 8,050nm at 14.00 kts
   Bunker at max displacement = 1,881 tons

Complement:
   474 - 617

Cost:
   £1.457 million / $5.829 million

Distribution of weights at normal displacement:
   Armament: 366 tons, 3.9 %
      - Guns: 366 tons, 3.9 %
   Armour: 1,463 tons, 15.7 %
      - Belts: 935 tons, 10.0 %
      - Armament: 206 tons, 2.2 %
      - Armour Deck: 284 tons, 3.0 %
      - Conning Tower: 38 tons, 0.4 %
   Machinery: 2,859 tons, 30.6 %
   Hull, fittings & equipment: 3,107 tons, 33.3 %
   Fuel, ammunition & stores: 1,332 tons, 14.3 %
   Miscellaneous weights: 205 tons, 2.2 %
      - Hull below water: 70 tons
      - Hull above water: 30 tons
      - On freeboard deck: 85 tons
      - Above deck: 20 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     9,107 lbs / 4,131 Kg = 51.2 x 7.1 " / 180 mm shells or 1.2 torpedoes
   Stability (Unstable if below 1.00): 1.24
   Metacentric height 3.2 ft / 1.0 m
   Roll period: 13.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.31
   Seaboat quality  (Average = 1.00): 1.06

Hull form characteristics:
   Hull has rise forward of midbreak,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.534 / 0.544
   Length to Beam Ratio: 9.43 : 1
   'Natural speed' for length: 23.27 kts
   Power going to wave formation at top speed: 59 %
   Trim (Max stability = 0, Max steadiness = 100): 47
   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:   16.72 %,  25.43 ft / 7.75 m,  25.43 ft / 7.75 m
      - Forward deck:   20.00 %,  25.43 ft / 7.75 m,  25.43 ft / 7.75 m
      - Aft deck:   53.28 %,  16.40 ft / 5.00 m,  16.40 ft / 5.00 m
      - Quarter deck:   10.00 %,  16.40 ft / 5.00 m,  16.40 ft / 5.00 m
      - Average freeboard:      19.72 ft / 6.01 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 112.7 %
      - Above water (accommodation/working, high = better): 162.0 %
   Waterplane Area: 21,369 Square feet or 1,985 Square metres
   Displacement factor (Displacement / loading): 109 %
   Structure weight / hull surface area: 96 lbs/sq ft or 466 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.95
      - Longitudinal: 1.50
      - Overall: 1.00
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room

Quarterdeck armor represents 13t of additional armor for steering equipment

[TacCovert4]

Maybe weigh it out and specifically note thickness?

[Jefgte]

IMO,
Belt 100
Deck 20
The bridge is really too thin.
If you can, increase displacement to 8200t and increase the deck to 35mm.
Or reduce the speed & the range a bit.

[Kaiser Kirk]

Is there a way we can handle doing additional steering gear protections? Jeanne d'Arc has the same...

I don't even know what Jeanne d'Arc is - one of your N7 ships or an OTL French ?

I think if you're proposing something novel, it's contingent on you to explain how/why it works.

The ship I replied on has a 10% quarter deck for a 165m ship.
So that's 16.5 me between the aft bulkhead and the stern. 
...how far back from the stern are the rudders?
So..15m?
How many rudders? 1...2...3? 
So say 2,
so 2 x 15m long areas to protect ?
On this ship...the answer would change for others.

So....how are 1917 vessels rudders moved?  I've seen references to 'steering chains' 'steering gear', then there's somewhere some 'steering engines'.

How much space to those take?
To move a ships rudder, probably pretty heavy duty, and one out and one in. So a meter? 2/3rds a meter?

Ok, we can do *that* math.
A 2ft x 2ft box is 8 sq.ft of armor surface per linear foot.   
1x1ft x 1" squares of armor plate were, I believe, called 40lb plate.
So that's 320lbs per linear foot.
15m is 49.2ft.
or 15,744 per steering gear
total of 31,488
but these are naval standard tons so divide by 2240
and we get 14tons of armor for a 25mm plate.

But then....
How high do those areas need to be be ?
Put a dome over where the chains tie into the top of the rudder?
Then make sure it's either roomy enough, or thick enough, that dents from shell fragments hitting it don't matter.

So there's more needed. How much? I dunno.

So , if we leave the rudder heads exposed, the 13 tons, 'buys' (13/14 * 25) = 23mm of armor protection.
Which stops splinters of up to 138mm.

But that's without including the rudder heads and supporting structures.

So even after that math... I *really* have no idea what 13tons buys in terms of shell resistance.

so a bit more than 'Quarterdeck armor represents 13t of additional armor for steering equipment" would be nice if you want it to work.

That should really be a case of you posting a methodology for folks to review, and then if no great protests, you doing the math, not me.


Plus....what the heck is protecting your propeller shafts, and what keeps your stern from becoming a colander ?

[snip]

So best forget it then, message received.

EDIT: In retrospect, that came off a bit harsh. Apologies

[snip]

An additional capital ship design under consideration for a 1916 laydown. Named for the great unifier of Wessex during the Second Empire's reconquest of its Albion holdings.

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:   10.2" / 260 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:   13.4" / 340 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: 3.15" / 80 mm
   Forecastle: 0.00" / 0 mm  Quarter deck: 1.18" / 30 mm

   - Conning towers: Forward 9.45" / 240 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: 11,430 tons, 26.1 %
      - Belts: 4,257 tons, 9.7 %
      - Torpedo bulkhead: 929 tons, 2.1 %
      - Armament: 2,854 tons, 6.5 %
      - Armour Deck: 3,137 tons, 7.2 %
      - Conning Tower: 253 tons, 0.6 %
   Machinery: 5,961 tons, 13.6 %
   Hull, fittings & equipment: 16,268 tons, 37.2 %
   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):
     65,224 lbs / 29,585 Kg = 54.4 x 13.4 " / 340 mm shells or 8.6 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 %): 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 965 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.96
      - Longitudinal: 1.43
      - 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

[The Rock Doctor]

It would be a powerful (and expensive) ship.

Is the torpedo bulkhead sufficiently thick, given how popular torpedoes are these days?