Imperial Roman Navy: 1910-1914 Designs

[Desertfox]

We have officially entered WWII ship territory in 1914...

[snip]

There is a few historical near-contemperaries in size and purpace: The British Lightfoot class Flotilla Leaders (1915) and follow-ons (noted as partial inspiration for the historic contre-torpilleurs), and the German B 97 (1915), S113 (1918) classes. While armament is heavier than the mentioned designs (sans S 113 which had 4x150mm), here we have had actual engagements with light torpedo craft that would inform heavier armament.

[Desertfox]

I should have said, that was in relation to the B design, twin M&H are way too early. I do think the bigger guns are actually worse against light crafts, ROF and turning rates will be worse than smaller ones. I am seriously regretting not investing into 4" guns myself.

[Guinness]

The Royal Navy had reservations about putting 6" guns on 3000 ton cruisers because they felt those ships were too lively. The manually operated mountings were too hard to keep on target. Ultimately fire control helped the matter somewhat, but they weren't truly happy with 6" guns on such small a ship until powered mountings came along. So one would expect such reservations to apply to 1500t destroyers too.

The other argument for smaller calibers on destroyers and lighter cruisers was always one of rate of fire. This becomes less of an issue as engagement ranges increase, but returns with dual-purpose guns.

[snip]

Revised B design. Drop M&H, return to 36000 shp, add 5t misc weight

LRD-14B, Imperial Roman Destroyer laid down 1914

Displacement:
   1,500 t light; 1,567 t standard; 1,760 t normal; 1,914 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (354.32 ft / 344.49 ft) x 31.17 ft x (13.94 / 14.75 ft)
   (108.00 m / 105.00 m) x 9.50 m  x (4.25 / 4.50 m)

Armament:
      8 - 3.94" / 100 mm 45.0 cal guns - 30.86lbs / 14.00kg shells, 225 per gun
     Quick firing guns in deck mounts, 1909 Model
     3 x Twin mounts on centreline ends, majority forward
      1 raised mount - superfiring
     1 x Twin mount on centreline, aft deck forward
      1 raised mount aft
      2 - 1.77" / 45.0 mm 50.0 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 forward
      2 raised mounts
      4 - 0.26" / 6.5 mm 110.0 cal guns - 0.01lbs / 0.00kg shells, 5,000 per gun
     Machine guns in deck mounts, 1911 Model
     4 x Single mounts on sides, evenly spread
      4 raised mounts
      Weight of broadside 254 lbs / 115 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         -               -

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 36,000 shp / 26,856 Kw = 32.26 kts
   Range 3,500nm at 14.00 kts
   Bunker at max displacement = 347 tons

Complement:
   135 - 176

Cost:
   £0.260 million / $1.039 million

Distribution of weights at normal displacement:
   Armament: 38 tons, 2.2 %
      - Guns: 38 tons, 2.2 %
   Armour: 9 tons, 0.5 %
      - Armament: 9 tons, 0.5 %
   Machinery: 994 tons, 56.5 %
   Hull, fittings & equipment: 418 tons, 23.8 %
   Fuel, ammunition & stores: 260 tons, 14.8 %
   Miscellaneous weights: 40 tons, 2.3 %
      - On freeboard deck: 40 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     385 lbs / 175 Kg = 12.6 x 3.9 " / 100 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.32
   Metacentric height 1.4 ft / 0.4 m
   Roll period: 11.0 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.32
   Seaboat quality  (Average = 1.00): 1.10

Hull form characteristics:
   Hull has rise forward of midbreak,
     a normal bow and a round stern
   Block coefficient (normal/deep): 0.411 / 0.423
   Length to Beam Ratio: 11.05 : 1
   'Natural speed' for length: 18.56 kts
   Power going to wave formation at top speed: 65 %
   Trim (Max stability = 0, Max steadiness = 100): 64
   Bow angle (Positive = bow angles forward): 20.00 degrees
   Stern overhang: 2.07 ft / 0.63 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   10.00 %,  21.33 ft / 6.50 m,  19.69 ft / 6.00 m
      - Forward deck:   15.00 %,  19.69 ft / 6.00 m,  19.69 ft / 6.00 m
      - Aft deck:   60.00 %,  11.48 ft / 3.50 m,  11.48 ft / 3.50 m
      - Quarter deck:   15.00 %,  11.48 ft / 3.50 m,  11.48 ft / 3.50 m
      - Average freeboard:      13.60 ft / 4.15 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 190.1 %
      - Above water (accommodation/working, high = better): 123.2 %
   Waterplane Area: 6,655 Square feet or 618 Square metres
   Displacement factor (Displacement / loading): 60 %
   Structure weight / hull surface area: 31 lbs/sq ft or 153 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.79
      - Overall: 0.57
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

[snip]

Slightly tweeked and updated Jeanne d'Arc

Jeanne d'Arc, Imperial Roman Large Armored Cruiser laid down 1914

Displacement:
   28,000 t light; 29,490 t standard; 31,669 t normal; 33,413 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (702.12 ft / 685.70 ft) x 101.71 ft x (28.54 / 29.79 ft)
   (214.00 m / 209.00 m) x 31.00 m  x (8.70 / 9.08 m)

Armament:
      8 - 13.39" / 340 mm 45.0 cal guns - 1,212.54lbs / 550.00kg shells, 110 per gun
     Breech loading guns in turret on barbette mounts, 1909 Model
     2 x Quad mounts on centreline ends, evenly spread
      20 - 5.51" / 140 mm 55.0 cal guns - 85.98lbs / 39.00kg shells, 175 per gun
     Quick firing guns in casemate mounts, 1909 Model
     16 x Single mounts on sides, aft evenly spread
     4 x Single mounts on sides, forward evenly spread
      4 hull mounts in casemates- Limited use in heavy seas
      16 - 3.94" / 100 mm 45.0 cal guns - 30.86lbs / 14.00kg shells, 350 per gun
     Quick firing guns in deck and hoist mounts, 1906 Model
     8 x Twin mounts on sides, aft evenly spread
      8 raised mounts
      10 - 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
     10 x Single mounts on sides, evenly spread
      Weight of broadside 11,914 lbs / 5,404 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   9.45" / 240 mm   445.70 ft / 135.85 m   18.04 ft / 5.50 m
   Ends:   1.97" / 50 mm   239.96 ft / 73.14 m   9.84 ft / 3.00 m
     Main Belt covers 100 % of normal length

   - Torpedo Bulkhead - Additional damage containing bulkheads:
      1.57" / 40 mm   445.70 ft / 135.85 m   28.54 ft / 8.70 m
   Beam between torpedo bulkheads 89.40 ft / 27.25 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   0.98" / 25 mm      3.94" / 100 mm
   3rd:   0.59" / 15 mm   0.20" / 5 mm      0.79" / 20 mm

   - Armoured deck - single deck:
   For and Aft decks: 2.36" / 60 mm
   Forecastle: 0.59" / 15 mm  Quarter deck: 1.38" / 35 mm

   - Conning towers: Forward 9.45" / 240 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 4 shafts, 128,000 shp / 95,488 Kw = 29.56 kts
   Range 7,000nm at 14.00 kts
   Bunker at max displacement = 3,923 tons

Complement:
   1,186 - 1,543

Cost:
   £3.469 million / $13.875 million

Distribution of weights at normal displacement:
   Armament: 2,156 tons, 6.8 %
      - Guns: 2,156 tons, 6.8 %
   Armour: 7,980 tons, 25.2 %
      - Belts: 3,453 tons, 10.9 %
      - Torpedo bulkhead: 741 tons, 2.3 %
      - Armament: 1,655 tons, 5.2 %
      - Armour Deck: 1,927 tons, 6.1 %
      - Conning Tower: 204 tons, 0.6 %
   Machinery: 4,931 tons, 15.6 %
   Hull, fittings & equipment: 10,993 tons, 34.7 %
   Fuel, ammunition & stores: 3,669 tons, 11.6 %
   Miscellaneous weights: 1,940 tons, 6.1 %
      - Hull below water: 1,350 tons
      - Hull above water: 150 tons
      - On freeboard deck: 400 tons
      - Above deck: 40 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     40,344 lbs / 18,300 Kg = 33.6 x 13.4 " / 340 mm shells or 5.6 torpedoes
   Stability (Unstable if below 1.00): 1.28
   Metacentric height 8.0 ft / 2.4 m
   Roll period: 15.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.41
   Seaboat quality  (Average = 1.00): 1.12

Hull form characteristics:
   Hull has rise forward of midbreak,
     a normal bow and a round stern
   Block coefficient (normal/deep): 0.557 / 0.563
   Length to Beam Ratio: 6.74 : 1
   'Natural speed' for length: 26.19 kts
   Power going to wave formation at top speed: 56 %
   Trim (Max stability = 0, Max steadiness = 100): 62
   Bow angle (Positive = bow angles forward): 20.00 degrees
   Stern overhang: 5.97 ft / 1.82 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  28.71 ft / 8.75 m,  28.71 ft / 8.75 m
      - Forward deck:   15.00 %,  28.71 ft / 8.75 m,  28.71 ft / 8.75 m
      - Aft deck:   50.00 %,  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:      22.84 ft / 6.96 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 98.7 %
      - Above water (accommodation/working, high = better): 171.2 %
   Waterplane Area: 48,977 Square feet or 4,550 Square metres
   Displacement factor (Displacement / loading): 106 %
   Structure weight / hull surface area: 175 lbs/sq ft or 853 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.95
      - Longitudinal: 1.53
      - Overall: 1.00
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

Quarter deck armor represents a 25mm armored deck and an additional 35t of armor protection for stearing gear rather than a uniform 35mm armored deck.

Misc Distribution
--Below Water (1350t)
----1235t Electric Drives
----40t Additional Pumps
----35t Enhanced Subdivision
----20t Enhanced Damage Control Equipment
----20t Enhanced Ventilation and Crew Comfort
--Above Water (150t)
----50t Improved Officer Accommodations
----50t Improved Crew Accommodations
----20t Enhanced Ventilation and Crew Comfort
----20t Short-Range Wireless (x2)
----10t Construction Reserve
--On Deck (400t)
----216t 1912 Fire Control
----60t Flag Facilities
----20t Admiralty Accommodations
----50t Long-Range Wireless (x2)
----20t Enhanced Ventilation and Crew Comfort
----20t Night Fighting Equipment
----14t Construction Reserve
--Above Deck (40t)
----20t Improved Aquisition Structures
----10t Additional Searchlights
----10t Improved Signaling Equipment

[Guinness]

1940 tons of misc weight is... a lot. Why do you need to account for electric drives in misc weight? Is that a SS3B3 deficiency I missed?

[TacCovert4]

1940 tons of misc weight is... a lot. Why do you need to account for electric drives in misc weight? Is that a SS3B3 deficiency I missed?

It's in the rules. 

If you go with electric drives, it's 25% of your engines in additional Misc weight.  But you get a 15% increase to range, and your ship gets additional damage control capabilities due to increased compartmentalization and lack of long shaft runs going all the way to the turbines, plus your boiler and turbine rooms can be staggered since they're driving generators.  Or your diesels.  You can stack the Diesel bonus AND the electric drive bonus.

A general rule for me is that if a ship has more than 6000nm range, electric drives may be worth it. 

[snip]

Springsharp has never properly accounted for the weight difference between drive types. Rather than it being a meaningless checkbox, when setting up the rules I added some misc weight modifiers and benifits.

[Kaiser Kirk]

Springsharp has never properly accounted for the weight difference between drive types. Rather than it being a meaningless checkbox, when setting up the rules I added some misc weight modifiers and benifits.

For my part on the electric drive vessels I mark the misc weight as 'turbogenerators' just to highlight it.
I'm finding it hard to fit into my cruisers, but still looking at it for battlewagons and then Auxiliaries.

From a combat perspective, being able to fully reverse one set of shafts made 'standard' US battleships more maneuverable, which will show up trying to avoid torpedoes - reducing their To Hit.
The allowance for torpedo flotation damage will be higher than the SS default, as a result of the better subdivision allowed. 

[Guinness]

It's in the rules.

So it is. I find the range bonus interesting. Is that because turbines could always be run at their optimal speed?

[Kaiser Kirk]

So it is. I find the range bonus interesting. Is that because turbines could always be run at their optimal speed?

While I can't say that's why Snip did it, that was the real life results :)

[snip]

So it is. I find the range bonus interesting. Is that because turbines could always be run at their optimal speed?

While I can't say that's why Snip did it, that was the real life results :)

That is why I did it. Same reason why non-direct drives and diesels have range bonuses

[maddox]

Way more expensive to do, but the benefits were clear. 
There is a reason real steam-turbine powered ships are getting rare. The only big selling point for those is when there is waste heat to recover*, or nuke teakettles involved.
The rest are gas-turbine electric, (with steam power recovery), pure diesel, or diesel-electric.
I worked on a diesel electric plant last year.   3 sets of twin 750kw/1000HP units on azipod swivels. 2 fixed bow thrusters and 1  retractable swivel bow unit.
That ship had a 4" stationkeeping accuracy in 7 beaufort. Logical actualy, as it could be used as a mobile repair yard for oil platforms. The big crane can lift 250 tons at 60m full extension.
(they use the small crane with a water filled bladder, combined with the ballast tanks as counterweight, the pump-array to keep that ballet orchestrated is another sight to behold. Man, I loved that job.)

*LNG carriers for example, those vent gas to keep the spherical tanks cooled, that vented gas is used for the turbine.

[TacCovert4]

Way more expensive to do, but the benefits were clear. 
There is a reason real steam-turbine powered ships are getting rare. The only big selling point for those is when there is waste heat to recover*, or nuke teakettles involved.
The rest are gas-turbine electric, (with steam power recovery), pure diesel, or diesel-electric.
I worked on a diesel electric plant last year.   3 sets of twin 750kw/1000HP units on azipod swivels. 2 fixed bow thrusters and 1  retractable swivel bow unit.
That ship had a 4" stationkeeping accuracy in 7 beaufort. Logical actualy, as it could be used as a mobile repair yard for oil platforms. The big crane can lift 250 tons at 60m full extension.
(they use the small crane with a water filled bladder, combined with the ballast tanks as counterweight, the pump-array to keep that ballet orchestrated is another sight to behold. Man, I loved that job.)

*LNG carriers for example, those vent gas to keep the spherical tanks cooled, that vented gas is used for the turbine.

Yeah, Turbo Electric or Diesel Electric also have some interesting tactical benefits.  The ship can be run in reverse at the same propeller RPM as forward, so like the USS Maryland it can 'back' its way to port if it's suffered severe bow damage.  And there's almost no 'spool up' in changing RPMs or even prop direction, so a T-E or D-E ship can change speed or even course (using the props at different speeds to assist the rudders) extremely rapidly.

The ability to use full power in reverse is why I'm putting Electrics on all of my landing ships.  If they are grounded in the process of running Marines ashore, they can use full power to pull themselves off.  Plus I add tonnage for a hydraulic motored winch and stern anchor which can be dropped or run out by boat to give yet more pulling power for an un-beaching.

And the efficiency of Diesel-Electric makes it ideal for the Pacific.  In general, if you're concerned about the range vs weight, over 6000nm range is where Electrics start overtaking direct drives.  By the time you get to 9000nm range, if you're not using electric motors, you're wasting tonnage.