Imperial Roman Navy: 1915-1919 Designs

[snip]

Eh, its a 3.5 vs 4 year build time, thats not a huge difference. The nice thing is the cost-per-turn is about the same, so I can plan with a rough tonnage commitment in mind and not have huge alterations if the need arrises.

[snip]

Given I have a need to replace a lot of destroyers, the design below is under consideration as the new "standard" Destroyer type of the IRN to replace the now-threadbear ranks of the F and G classes in that role. Possessing enough range to make the Brest-Havana run at 14 knots and have a little gas in the tank when it gets there, or make the Brest-Galveston run in one go, this is seen as both a decent torpedo platform in a Ironclad Bay type scenario as well as a acceptable general fleet screen. The class will bear the names of the commanders of the destroyers lost at Ironclad Bay.

Rainier Marion, Imperial Roman Destroyer laid down 1915

Displacement:
   1,500 t light; 1,565 t standard; 1,802 t normal; 1,992 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 / 12.38 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 - 85.98lbs / 39.00kg shells, 150 per gun
     Quick firing guns in deck mounts, 1909 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, 1911 Model
     4 x Single mounts on sides, evenly spread
      4 raised mounts
      Weight of broadside 344 lbs / 156 kg

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 34,000 shp / 25,364 Kw = 31.34 kts
   Range 4,500nm at 14.00 kts
   Bunker at max displacement = 427 tons

Complement:
   137 - 179

Cost:
   £0.305 million / $1.218 million

Distribution of weights at normal displacement:
   Armament: 76 tons, 4.2 %
      - Guns: 76 tons, 4.2 %
   Machinery: 970 tons, 53.8 %
   Hull, fittings & equipment: 424 tons, 23.5 %
   Fuel, ammunition & stores: 302 tons, 16.8 %
   Miscellaneous weights: 30 tons, 1.7 %
      - On freeboard deck: 30 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     500 lbs / 227 Kg = 6.0 x 5.5 " / 140 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.49
   Metacentric height 1.9 ft / 0.6 m
   Roll period: 10.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.31
   Seaboat quality  (Average = 1.00): 1.11

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: 67 %
   Trim (Max stability = 0, Max steadiness = 100): 45
   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): 185.1 %
      - Above water (accommodation/working, high = better): 152.6 %
   Waterplane Area: 7,436 Square feet or 691 Square metres
   Displacement factor (Displacement / loading): 64 %
   Structure weight / hull surface area: 32 lbs/sq ft or 156 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.84
      - Overall: 0.57
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room

Misc weight to include 6x530mm torps in two triple mounts and modern fire control.

[TacCovert4]

Why not just strap a pair of light cruisers to each side of the hull.  36 secondary guns.....jesus.....

[maddox]

"Self Propelled Armed bulges". Just make sure the superstructure stays below the firing lines.

Other option, use "razed" merchant hulls filled with cork, and refit them with 2% displacement in 4.5-5" guns.  Presto, cheap armor and a few extra secundaries. 

(in Nverse 3 this would have ended , Yep, the self mobile bulges absorb the mine and torpedo hits easely, but alas, the cork was glued and waterproofed with a very flamable substance.  Now you have an inferno raging next to the battleship. Oh, look, secundary munition cooking off. Oh, somebody didn't close an ammonution hoist. Oops) 
https://www.youtube.com/watch?v=d1up-TRMxdo

[The Rock Doctor]

The battleships certainly show an interest in beating off torpedo-attack.

Is Rome consciously making a size versus numbers decision with respect to destroyers?

[snip]

The 140/100 mix is probly going to prove problematic for FC, but that is a lesson the current conflict wont teach because none of the ships with that armament mix are in theater. Once that becomes apparent, the twin 100s will likely be replaced later in the ship's life.

For destroyers, the increase in size is twofold. First is how fragile smaller units have proven to be. Second is that smaller Protected Cruisers have also proven to be quite fragile in similar environments. The Marion's are intended as both a more functional replacement for the smaller, fragile destroyers and as a screen replacement for smaller Protected Cruisers given they will distribute similar firepower over multiple hulls for about the same cost. Protected Cruisers are going to grow and become more specialized into ether "anchor" ships for destroyer task groups or trade protection ships, things like the Colbert from earlier and LRC-15. Specialized torpedo delivery platforms are going to go as small and stealthy as possible, mainly MTBs and Subs, to allow for saturation against targets.

[Kaiser Kirk]

an extended bulbous bow and a cruiser stern

I thought those bows were outlawed, but I don't see it, just the transom.

Curious

The LBS-15 program has been pushed back to 1916 due to a need for war repairs anticipated to take up most of the year. The designs are mostly updated version of the LBS-15 program, with the elimination of the 16x340mm design. LBS-16A is a modified Audax hull, while LBS-16B is a new hull. Both designs share a similar top speed to work with the Audax class, identical armament, and similar vertical protection. By virtue of being larger, LBS-16B carries more extensive and stronger horizontal protection, a thicker TDS, and has better ability to absorb hits.

LBS-16A, Imperial Roman Republic Battleship laid down 1916

Displacement:
   29,600 t light; 31,575 t standard; 33,731 t normal; 35,455 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (633.20 ft / 623.36 ft) x 101.71 ft x (27.07 / 28.27 ft)
   (193.00 m / 190.00 m) x 31.00 m  x (8.25 / 8.62 m)

Armament:
      8 - 16.14" / 410 mm 45.0 cal guns - 2,120.84lbs / 962.00kg shells, 110 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
     1 x 2-gun mount on centreline, aft deck forward
      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
     20 x Single mounts on sides, evenly spread
      8 hull mounts in casemates- Limited use in heavy seas

I think the belt is too thin, but that's up to you. At the time of design, you would know it to be vulnerable to your own guns at the currently accurate combat ranges,
and you just had a demonstration you can't always choose the range you fight at. .


I see your joining the Parthian "20 secondary" club.
I don't like the tertiaries... extra batteries pain to track.
Generally how I address mixed batteries for main guns is I pretend they are effectively 2-3 ships firing at one target, or a -5 penalty.
For tertiaries, so far they've been deck mounts, and I presume the secondaries are doing the ranging and the tertiary are just following some pointer for direction and elevation.
There's been a couple times I let secondaries go to 'local range finder', but I do not expect the tertiary to have them.

[snip]

Both LBS-16 designs carry the same secondary suite as the Audax class, which finish up in 1915. The newer designs, including Jeanne d'Arc have slightly more space-efficient arrangements. I'm intending that the 100s are eventualy realized as a detriment more than a supplement to the 140s are ether later replaced with 140mm deck mounts or are removed. Since none of those designs have seen combat serivce and nothing else has that sort of mixed anti-small stuff battery, unless this drags on long enough to see the Audax get in on the action its not going to get noticed this conflict.

I can get the belts up to 340mm by shaving 10 of the main decks, which is  reasonable but Im not sure how much additional immunity zone that buys me against her own guns or the Aztec 360mm. Its probly a worthwhile trade to make now, new engines later can always free up strenght for the deck when long-range combat is more apparent.

[Kaiser Kirk]

I'll point out the 11" barbettes are also problematic.
While not hit often, it seems odd to put 440mm on the face and 280 on the stalk.

Also it's curious that you have your casement guns in 100mm boxes , which I suspect removes much of the weight savings
of no upper belt. I tend to go with an armored face and then armored screens internally.

[Jefgte]

...I'm intending that the 100s are eventualy realized as a detriment more than a supplement to the 140s are ether later replaced with 140mm deck mounts or are removed...

In a few years, you need AA guns. 100, 90, 76,2.
Remove some 140 could be an interesting option to install them.

;)

[snip]

Some revision to LBS-16B to incorporate feedback. LBS-16A has proven to be a little to tight to accommodate all of the noted points.

LBS-16B, Imperial Roman Battleship laid down 1916

Displacement:
   34,325 t light; 36,400 t standard; 38,723 t normal; 40,581 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (685.71 ft / 672.57 ft) x 101.71 ft x (29.53 / 30.75 ft)
   (209.00 m / 205.00 m) x 31.00 m  x (9.00 / 9.37 m)

Armament:
      8 - 16.14" / 410 mm 45.0 cal guns - 2,120.85lbs / 962.00kg shells, 110 per gun
     Breech loading guns in turret on barbette mounts, 1915 Model
     4 x 2-gun mounts on centreline ends, evenly spread
      2 raised mounts - superfiring
      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
     14 x Single mounts on sides, aft evenly spread
     6 x Single mounts on sides, forward evenly spread
      6 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, evenly spread
      8 raised mounts
      4 - 1.77" / 45.0 mm 50.0 cal guns - 3.31lbs / 1.50kg shells, 75 per gun
     Anti-air guns in deck mounts, 1910 Model
     4 x Single mounts on side ends, evenly spread
      4 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
      10 raised mounts
      Weight of broadside 19,194 lbs / 8,706 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   13.6" / 345 mm   437.17 ft / 133.25 m   18.04 ft / 5.50 m
   Ends:   2.36" / 60 mm   235.37 ft / 71.74 m   9.84 ft / 3.00 m
     Main Belt covers 100 % of normal length

   - Torpedo Bulkhead - Additional damage containing bulkheads:
      3.15" / 80 mm   437.17 ft / 133.25 m   31.17 ft / 9.50 m
   Beam between torpedo bulkheads 82.02 ft / 25.00 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   17.3" / 440 mm   7.09" / 180 mm      11.8" / 300 mm
   2nd:   3.94" / 100 mm   1.97" / 50 mm      3.94" / 100 mm
   3rd:   0.59" / 15 mm         -         1.97" / 50 mm
   4th:   0.39" / 10 mm         -               -

   - Armoured deck - single deck:
   For and Aft decks: 3.15" / 80 mm
   Forecastle: 0.79" / 20 mm  Quarter deck: 1.77" / 45 mm

   - Conning towers: Forward 13.78" / 350 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 4 shafts, 70,000 shp / 52,220 Kw = 24.25 kts
   Range 7,000nm at 14.00 kts
   Bunker at max displacement = 4,181 tons

Complement:
   1,379 - 1,794

Cost:
   £5.402 million / $21.608 million

Distribution of weights at normal displacement:
   Armament: 3,835 tons, 9.9 %
      - Guns: 3,835 tons, 9.9 %
   Armour: 13,235 tons, 34.2 %
      - Belts: 4,900 tons, 12.7 %
      - Torpedo bulkhead: 1,588 tons, 4.1 %
      - Armament: 3,616 tons, 9.3 %
      - Armour Deck: 2,792 tons, 7.2 %
      - Conning Tower: 340 tons, 0.9 %
   Machinery: 2,608 tons, 6.7 %
   Hull, fittings & equipment: 13,076 tons, 33.8 %
   Fuel, ammunition & stores: 4,398 tons, 11.4 %
   Miscellaneous weights: 1,570 tons, 4.1 %
      - Hull below water: 850 tons
      - Hull above water: 200 tons
      - On freeboard deck: 480 tons
      - Above deck: 40 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     61,020 lbs / 27,678 Kg = 29.0 x 16.1 " / 410 mm shells or 10.3 torpedoes
   Stability (Unstable if below 1.00): 1.24
   Metacentric height 7.5 ft / 2.3 m
   Roll period: 15.6 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.70
   Seaboat quality  (Average = 1.00): 1.39

Hull form characteristics:
   Hull has rise forward of midbreak,
     a normal bow and a round stern
   Block coefficient (normal/deep): 0.671 / 0.675
   Length to Beam Ratio: 6.61 : 1
   'Natural speed' for length: 25.93 kts
   Power going to wave formation at top speed: 49 %
   Trim (Max stability = 0, Max steadiness = 100): 36
   Bow angle (Positive = bow angles forward): 15.00 degrees
   Stern overhang: 5.45 ft / 1.66 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:   20.00 %,  28.71 ft / 8.75 m,  28.71 ft / 8.75 m
      - Aft deck:   45.00 %,  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:      23.29 ft / 7.10 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 82.3 %
      - Above water (accommodation/working, high = better): 165.7 %
   Waterplane Area: 53,415 Square feet or 4,962 Square metres
   Displacement factor (Displacement / loading): 106 %
   Structure weight / hull surface area: 202 lbs/sq ft or 988 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.95
      - Longitudinal: 1.52
      - Overall: 1.00
   Excellent machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Good seaboat, rides out heavy weather easily

Quarter deck represents a 25mm uniform armored deck and 78t additional armor protection for stearing gear.

On the subject of barbettes, a quick looksee of Conways leads me to the conclusion that barbettes thicker than about 300mm for this era is a bit out of norm, the only ships I found with thicker were the Standards (330mm) and Bayern (350mm). My gut tells me that this is because of the extremally curved nature of the barbette lending additional thickness on anything but a perpendicular impact. Additionally, outside of the Standards, turret faces are typically much closer in thickness to the belt than this design. So based on OLT trends, the 440mm turret faces of this design are more out of line with trends than the barbettes are.

[snip]

Some slight tweaks to the Rainier Marion. Little bit less powerful engines for some additional Misc weight for goodies.

Rainier Marion, Imperial Roman Destroyer laid down 1915

Displacement:
   1,500 t light; 1,565 t standard; 1,802 t normal; 1,992 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 / 12.38 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 - 85.98lbs / 39.00kg shells, 150 per gun
     Quick firing guns in deck mounts, 1909 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, 1911 Model
     4 x Single mounts on sides, evenly spread
      4 raised mounts
      Weight of broadside 344 lbs / 156 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 4,500nm at 14.00 kts
   Bunker at max displacement = 427 tons

Complement:
   137 - 179

Cost:
   £0.298 million / $1.191 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: 937 tons, 52.0 %
   Hull, fittings & equipment: 418 tons, 23.2 %
   Fuel, ammunition & stores: 302 tons, 16.8 %
   Miscellaneous weights: 60 tons, 3.3 %
      - On freeboard deck: 60 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     492 lbs / 223 Kg = 5.9 x 5.5 " / 140 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.29
   Metacentric height 1.5 ft / 0.5 m
   Roll period: 11.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.42
   Seaboat quality  (Average = 1.00): 1.15

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): 179.3 %
      - Above water (accommodation/working, high = better): 152.6 %
   Waterplane Area: 7,436 Square feet or 691 Square metres
   Displacement factor (Displacement / loading): 67 %
   Structure weight / hull surface area: 31 lbs/sq ft or 154 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.81
      - Overall: 0.56
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

Misc Wieght
--18t 6x530mm Torpedo Tubes (2x3 mounts centerline)
--8t 1912 FC
--25t LR Wireless
--3t Night Fighting Equipment
--6t Construction Reserve

[Kaiser Kirk]

On the subject of barbettes, a quick looksee of Conways leads me to the conclusion that barbettes thicker than about 300mm for this era is a bit out of norm, the only ships I found with thicker were the Standards (330mm) and Bayern (350mm). My gut tells me that this is because of the extremally curved nature of the barbette lending additional thickness on anything but a perpendicular impact. Additionally, outside of the Standards, turret faces are typically much closer in thickness to the belt than this design. So based on OLT trends, the 440mm turret faces of this design are more out of line with trends than the barbettes are.

Different Nations seemed to have differing ideas on the need for thick barbettes.
I believe I have read the USN felt as you guess- that the chance of a straight on hit was low, so the shell would almost always be going through a curved thickness.

I recall also reading the consideration that a turret face has large openings in it, which comprimised the strength of that plate and reduce it's ability to deform and absorb energy.

The Brits seemed to have viewed the turrets and barbettes as things that could be lost without loosing the ship.
Others felt that a penetration of the barbette carried the risk of flash detonating propellant.
Reported thickness can also be skewed by the use of varying thicknesses, for example French had thinner facing the other barbette, some figured the superstructure was equal to some thickness as well.

Upshot - I tend to make my turret faces >1" thicker and my barbettes the same or 1" less.

[Kaiser Kirk]

Some slight tweaks to the Rainier Marion. Little bit less powerful engines for some additional Misc weight for goodies.

how..Parthian of you
:)

[snip]

Some slight tweaks to the Rainier Marion. Little bit less powerful engines for some additional Misc weight for goodies.

how..Parthian of you
:)

I'd love to make her faster, but something had to give to get the range I wanted. Her donor-design as it were is S113, which were supposed to make 36knts but the only way to get that is to have seakeeping be in the surfaced submarine class.