Parthian vessels 1937 - 1940

[Kaiser Kirk]

The 1937 Drubust Coastal Battleship has already been posted in the prior Parthian thread.
This is meant for a spot to put these post 1936 designs.

[Kaiser Kirk]

The Parthians have long fielded sloops to serve as Coastal Patrol Cutters or low-end gunboats.

The Mackerel and Sturgeon Classes are 34 strong currently. They have a minesweeping role as well, and along with the 48 regular navy minesweepers they provide the peacetime MSW force.

There are also over 100 Patrol Sloops of the I, II and III series. As these are staffed by auxiliaries their cadres normally keep only 25% of them in service during peace.

These are all supplemented by the Auxiliary Gnat Class A, B and C variants. Those provide another 44 gunboats, 42 subchasers and 42 minesweepers for coastal waters.

There is a perceived need for a successor to the Sturgeon class.

Provided with extensive light armor, and shallow draft, it is very capable in the gunfire support role. Might even be a 'tough out' for an unarmored destroyer.

That is why it is named "Crab" ..that and the number of sea creatures I can find an Latin Alphabet translation of a Persian word for is very limited.

Like the predecessor, it has a 118mm Howitzer for shore bombardment, raised over the aft deck where the MSW gear is. It does have a full minesweeping suite.

The question internally is if the guns should be 2x2-Gun 90mm DP, or 2 x 1-Gun 115 DP.
The 115mm has a much greater direct fire effect for intership combat or engaging shore targets,
but the 90mm can put out a higher volume of fire, and likely a greater shell burst volume for AA use.

Kharchang - Crab, Parthian Coastal Patrol Cutter laid down 1937

Displacement:
    460 t light; 520 t standard; 562 t normal; 595 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
    (162.84 ft / 160.76 ft) x 23.79 ft x (8.76 / 9.18 ft)
    (49.63 m / 49.00 m) x 7.25 m  x (2.67 / 2.80 m)

Armament:
      2 - 4.53" / 115 mm 47.0 cal guns - 55.12lbs / 25.00kg shells, 440 per gun
      Dual purpose guns in deck mounts, 1930 Model
      2 x Single mounts on centreline, forward evenly spread
        1 raised mount
      1 - 4.65" / 118 mm 21.0 cal gun - 59.52lbs / 27.00kg shells, 300 per gun
      Breech loading gun in deck mount, 1926 Model
      1 x Single mount on centreline, aft deck forward
        1 raised mount
      8 - 1.18" / 30.0 mm 80.0 cal guns - 0.95lbs / 0.43kg shells, 3,000 per gun
      Anti-air guns in deck mounts, 1929 Model
      4 x 2-gun mounts on side ends, evenly spread
        4 raised mounts
      Weight of broadside 177 lbs / 80 kg

Armour:
  - Belts:        Width (max)    Length (avg)        Height (avg)
    Main:    1.38" / 35 mm    104.49 ft / 31.85 m    10.17 ft / 3.10 m
    Ends:    0.98" / 25 mm      56.23 ft / 17.14 m    10.17 ft / 3.10 m
      Main Belt covers 100 % of normal length

  - Hull void:
        0.00" / 0 mm      0.00 ft / 0.00 m    0.00 ft / 0.00 m

  - Gun armour:    Face (max)    Other gunhouse (avg)    Barbette/hoist (max)
    Main:    0.79" / 20 mm    0.31" / 8 mm              -
    2nd:    0.79" / 20 mm    0.31" / 8 mm              -
    3rd:    0.79" / 20 mm          -                  -

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

  - Conning towers: Forward 0.98" / 25 mm, Aft 0.00" / 0 mm

Machinery:
    Diesel Internal combustion generators,
    Electric motors, 2 shafts, 1,629 shp / 1,215 Kw = 16.00 kts
    Range 2,800nm at 12.00 kts
    Bunker at max displacement = 74 tons

Complement:
    57 - 75

Cost:
    £0.160 million / $0.639 million

Distribution of weights at normal displacement:
    Armament: 27 tons, 4.7 %
      - Guns: 27 tons, 4.7 %
    Armour: 136 tons, 24.3 %
      - Belts: 84 tons, 15.0 %
      - Armament: 10 tons, 1.8 %
      - Armour Deck: 41 tons, 7.2 %
      - Conning Tower: 1 tons, 0.3 %
    Machinery: 45 tons, 8.0 %
    Hull, fittings & equipment: 119 tons, 21.1 %
    Fuel, ammunition & stores: 102 tons, 18.2 %
    Miscellaneous weights: 133 tons, 23.7 %
      - Hull below water: 29 tons
      - Hull void weights: 5 tons
      - Hull above water: 33 tons
      - On freeboard deck: 35 tons
      - Above deck: 31 tons

Overall survivability and seakeeping ability:
    Survivability (Non-critical penetrating hits needed to sink ship):
      834 lbs / 378 Kg = 18.0 x 4.5 " / 115 mm shells or 0.8 torpedoes
    Stability (Unstable if below 1.00): 1.07
    Metacentric height 0.7 ft / 0.2 m
    Roll period: 12.3 seconds
    Steadiness    - As gun platform (Average = 50 %): 70 %
            - Recoil effect (Restricted arc if above 1.00): 0.76
    Seaboat quality  (Average = 1.00): 1.30

Hull form characteristics:
    Hull has a flush deck,
      a normal bow and a cruiser stern
    Block coefficient (normal/deep): 0.587 / 0.593
    Length to Beam Ratio: 6.76 : 1
    'Natural speed' for length: 12.68 kts
    Power going to wave formation at top speed: 60 %
    Trim (Max stability = 0, Max steadiness = 100): 54
    Bow angle (Positive = bow angles forward): 10.00 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 %,  11.81 ft / 3.60 m,  10.17 ft / 3.10 m
      - Forward deck:    32.50 %,  10.17 ft / 3.10 m,  8.53 ft / 2.60 m
      - Aft deck:    32.50 %,  8.53 ft / 2.60 m,  8.53 ft / 2.60 m
      - Quarter deck:    15.00 %,  8.53 ft / 2.60 m,  8.53 ft / 2.60 m
      - Average freeboard:        9.26 ft / 2.82 m
    Ship tends to be wet forward

Ship space, strength and comments:
    Space    - Hull below water (magazines/engines, low = better): 58.8 %
        - Above water (accommodation/working, high = better): 82.5 %
    Waterplane Area: 2,763 Square feet or 257 Square metres
    Displacement factor (Displacement / loading): 132 %
    Structure weight / hull surface area: 28 lbs/sq ft or 138 Kg/sq metre
    Hull strength (Relative):
        - Cross-sectional: 0.65
        - Longitudinal: 2.71
        - Overall: 0.75
    Caution: Hull subject to strain in open-sea
    Excellent machinery, storage, compartmentation space
    Cramped accommodation and workspace room
    Ship has slow, easy roll, a good, steady gun platform
    Good seaboat, rides out heavy weather easily

The Karchang or Crab class is a 1937 update to the Sturgeon Coastal Patrol Cutter.

Still intended as a light gunboat for the littoral regions.
The Coastal Patrol vessel is equipped with 115mm DP mounts forward.
Aft, a 118mm HOW is mounted in X, superimposed to be well clear of the equipment on the aft deck.
Compared to the Sturgeon class, the gunshields are far more robust.
The AA has been upgraded to the 'General Purpose' 30mm.

Armor :

The weather deck is the armored deck, from bow to stern,
while the Side is fully armored from deck to -0.5m below WL
Due to the lack of scuttles, additional tonnage is given to ventilarion



Engines :
45t * 0.55 = 24.75

Range : 2800 * 1.90 = 5,320nm = 443hr = 18 days

Misc Weight :
5t Reserve

AD
3t - 1930 FC
0t - SR radio
3t - NF Gear
25t - Hulesmeyer remote detection system.

OD
10t - 5t Motor launch, fits 16men (4t)  + engine
25t - Minesweeping gear on aft deck

HAW
1t - Enhanced ventilation (2x CO2 Compressor AC)
32t - 16 Marines (Section)

HBW
25t - Diesel-Electric
4t - Electric battery

Decks
+2.6 : Weather Deck, 20mm armor deck.
+0.1 : First Deck
-2.51 : Engineering

[Kaiser Kirk]

Exploring the Drubust with the 333L43mm guns used for 'Second Rate' ships.
That does also help the logistical arrangements, as the 333 is used for the Frawar, Dahae, Gilgamesh and Enki classes.

Displacement kept the same.
The difference with this version is the 6x 333mm battery, in the Byzantine style.
Unlike those designs, a TDS is not fitted,  tonnage going to D-E drive for compartmentation and maneuverability. Between the hull length, low L:B, and being able to run screws at different speeds- or even forward on starboard and reverse on port, the ship should be able to turn very easily and be a very difficult torpedo target.
Forgoing a TDS also keeps the citadel more compact, making the 'armored box over magazine and machinery' more efficient.

Length is 'merchant dock' length.
Beam is kept the same, with larger but fewer main guns.
Draft is down to 6.6

Armor is increased on the main guns,
The Armored Box on Magazines and Machinery- which thickens the belt and deck in those areas - is increased +10mm.
Belt armor is inclined.
Conn armor is increased.

Drubust "Fortress", Parthian Coastal Battleship laid down 1937

Displacement:
    12,500 t light; 13,948 t standard; 14,440 t normal; 14,834 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
    (462.37 ft / 456.04 ft) x 78.74 ft x (21.65 / 22.15 ft)
    (140.93 m / 139.00 m) x 24.00 m  x (6.60 / 6.75 m)

Armament:
      6 - 13.11" / 333 mm 43.0 cal guns - 1,311.75lbs / 595.00kg shells, 160 per gun
      Breech loading guns in turret on barbette mounts, 1934 Model
      2 x 3-gun mounts on centreline ends, evenly spread
      16 - 5.12" / 130 mm 47.0 cal guns - 85.98lbs / 39.00kg shells, 320 per gun
      Dual purpose guns in deck and hoist mounts, 1931 Model
      6 x 2-gun mounts on sides, evenly spread
        2 raised mounts
      2 x 2-gun mounts on centreline ends, evenly spread
        2 raised mounts
      8 - 1.46" / 37.0 mm 70.0 cal guns - 1.72lbs / 0.78kg shells, 6,000 per gun
      Anti-air guns in deck and hoist mounts, 1929 Model
      2 x 2 row quad mounts on centreline ends, evenly spread
        2 double raised mounts
      24 - 1.46" / 37.0 mm 70.0 cal guns - 1.72lbs / 0.78kg shells, 6,000 per gun
      Anti-air guns in deck and hoist mounts, 1929 Model
      4 x 2 row quad mounts on side ends, evenly spread
        4 raised mounts
      2 x 2 row quad mounts on sides amidships
        2 double raised mounts
      16 - 0.91" / 23.0 mm 90.0 cal guns - 0.44lbs / 0.20kg shells, 8,000 per gun
      Anti-air guns in deck mounts, 1929 Model
      8 x Twin mounts on sides, evenly spread
        8 double raised mounts
      Weight of broadside 9,308 lbs / 4,222 kg

Armour:
  - Belts:        Width (max)    Length (avg)        Height (avg)
    Main:    7.87" / 200 mm    296.42 ft / 90.35 m    9.38 ft / 2.86 m
    Ends:    1.97" / 50 mm    159.58 ft / 48.64 m    9.38 ft / 2.86 m
    Upper:    2.95" / 75 mm    296.42 ft / 90.35 m    8.40 ft / 2.56 m
      Main Belt covers 100 % of normal length
      Main Belt inclined -12.00 degrees (positive = in)

  - Hull void:
        0.00" / 0 mm      0.00 ft / 0.00 m    0.00 ft / 0.00 m

  - Gun armour:    Face (max)    Other gunhouse (avg)    Barbette/hoist (max)
    Main:    12.6" / 320 mm    4.72" / 120 mm        9.06" / 230 mm
    2nd:    2.56" / 65 mm    1.38" / 35 mm        1.97" / 50 mm
    3rd:    0.79" / 20 mm    0.31" / 8 mm        0.79" / 20 mm
    4th:    0.79" / 20 mm    0.31" / 8 mm        0.79" / 20 mm
    5th:    0.31" / 8 mm          -                  -

  - Armoured deck - multiple decks:
    For and Aft decks: 4.36" / 111 mm
    Forecastle: 1.38" / 35 mm  Quarter deck: 2.17" / 55 mm

  - Conning towers: Forward 11.81" / 300 mm, Aft 1.38" / 35 mm

Machinery:
    Diesel Internal combustion generators,  plus diesel motors,
    Electric motors, 3 shafts, 20,699 shp / 15,441 Kw = 20.00 kts
    Range 3,340nm at 14.00 kts
    Bunker at max displacement = 886 tons

Complement:
    658 - 856

Cost:
    £6.710 million / $26.840 million

Distribution of weights at normal displacement:
    Armament: 1,713 tons, 11.9 %
      - Guns: 1,713 tons, 11.9 %
    Armour: 4,472 tons, 31.0 %
      - Belts: 1,416 tons, 9.8 %
      - Armament: 897 tons, 6.2 %
      - Armour Deck: 1,991 tons, 13.8 %
      - Conning Towers: 168 tons, 1.2 %
    Machinery: 574 tons, 4.0 %
    Hull, fittings & equipment: 4,982 tons, 34.5 %
    Fuel, ammunition & stores: 1,940 tons, 13.4 %
    Miscellaneous weights: 760 tons, 5.3 %
      - Hull below water: 359 tons
      - Hull void weights: 75 tons
      - Hull above water: 24 tons
      - On freeboard deck: 30 tons
      - Above deck: 272 tons

Overall survivability and seakeeping ability:
    Survivability (Non-critical penetrating hits needed to sink ship):
      21,300 lbs / 9,662 Kg = 18.9 x 13.1 " / 333 mm shells or 3.1 torpedoes
    Stability (Unstable if below 1.00): 1.21
    Metacentric height 4.9 ft / 1.5 m
    Roll period: 14.9 seconds
    Steadiness    - As gun platform (Average = 50 %): 70 %
            - Recoil effect (Restricted arc if above 1.00): 0.71
    Seaboat quality  (Average = 1.00): 1.27

Hull form characteristics:
    Hull has rise forward of midbreak,
      a ram bow and a round stern
    Block coefficient (normal/deep): 0.650 / 0.653
    Length to Beam Ratio: 5.79 : 1
    'Natural speed' for length: 21.36 kts
    Power going to wave formation at top speed: 49 %
    Trim (Max stability = 0, Max steadiness = 100): 55
    Bow angle (Positive = bow angles forward): 15.00 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 %,  23.62 ft / 7.20 m,  21.16 ft / 6.45 m
      - Forward deck:    25.00 %,  21.16 ft / 6.45 m,  18.70 ft / 5.70 m
      - Aft deck:    40.00 %,  10.83 ft / 3.30 m,  10.83 ft / 3.30 m
      - Quarter deck:    15.00 %,  10.83 ft / 3.30 m,  10.83 ft / 3.30 m
      - Average freeboard:        15.37 ft / 4.68 m

Ship space, strength and comments:
    Space    - Hull below water (magazines/engines, low = better): 66.2 %
        - Above water (accommodation/working, high = better): 114.1 %
    Waterplane Area: 27,508 Square feet or 2,556 Square metres
    Displacement factor (Displacement / loading): 110 %
    Structure weight / hull surface area: 160 lbs/sq ft or 783 Kg/sq metre
    Hull strength (Relative):
        - Cross-sectional: 0.93
        - Longitudinal: 1.89
        - Overall: 1.00
    Excellent machinery, storage, compartmentation space
    Adequate accommodation and workspace room
    Ship has slow, easy roll, a good, steady gun platform
    Good seaboat, rides out heavy weather easily

A different exploration of the 'Coastal Battleship' concept.

Far more 'Coastal' this has a shallower draft and Diesel-Electric drive for
manueverability. 

Downsides - much more vulnerable to submarines and torpedoes.
Upsides - 2/3 the cost of the larger version.
Downside - no longer resistant to Dreadnaught firepower.
Upside - Still devasting to anything not a dreadnaught.


              S2            [S4]            S6
                  [  b]        (d)          [f]
                *      *                *      *
A [C1](a)                                        (h) C2  B                  AC     
                *      *                *      *
                  [c]        (e)            [g]
              P3              [P5]              P7

A/B : 333mm
C/S/P : 130mm
a-h  : 37mm
* : GAST 23mm mount. Double up.
[ ] = super imposed
( ) = double super



Armor

The armor is arranged in an upper citadel to exclude Bombs and HE/SAP shells, and a main citadel meant to stop non-battleship shells.

A 65mm box over the magazine and machinery thickens the deck and belt over those areas

Citadel Vitals
Belt : 265  (200+65)
Deck : 137  (35/2+55+65)

Citadel non-vitals
Belt : 200
Deck : 72 (35/2+55)


Belt :

75mm upper belt to exclude HE/SAP
Inclined 12% to 2.5/cos(15) = 2.558 = 2.56

200mm main belt over 65% of length.
Covers from main deck at 0.8m to -2m below WL.
2.8/cos (12) = 2.86255 = 2.86

Thickened to 265mm over magazines & machinery (59.78m)

50mm end belts


Deck :
574t    upper armor deck        0/35/0
1075t  main armor deck      35/55/55
342t    Magazine & machinery box 65mm
------
1,991t  needed
1,991t  modeled

Engine :
Diesel : 30% more, Electric 25% more = 55%
574*.55 = 315.7 = 316

Range : +75% diesel, +15% Electric = +90%
3340*1.90 = 6346 nm

Misc

Reserve :
75t

AD :
172t : FC
25t  : LR Radio
0t : SR Radio
25t : Searchlight Tower (NF)
25t : Hulesmeyer
25t : AS Radar

OD :
5t Paravanes
20t Seaplane
5t Gunpowder Cat.

HAW :
12t Extra Fire Suppresion
12t CO2 Compressor AC

HBW :
12t - Extra Pumps
31t - 1000kw Aux DE engines
316t - DE drive and turboelectric generators

Deck Levels
5.7 - Forecastle (unprotected)
3.3 - Weather Deck - Upper Armor Deck 35mm
        Upper Armor Belt
0.8  -  Main Deck - Armor Deck 55mm
-1.7  - 1st Platform Deck
      -2m lower main armor belt
-5.2  -  Engineering Deck
-6.34 - Double Bottom
-6.60 - Keel

[Jefgte]

I also tested a Panzerschiff with 2T3x381/42 - 21 kts. She is 16000t, too expensive for the colonial budget.

[Kaiser Kirk]

Warning : Blathering ahead !

Parthia is completing the 4-strong Arwand Class.
Armed with the 435mm gun, and armored against same, at 26 knots they required 45,000 tons.

What to build next?
The Aztecs have a monster ship afloat, we don't know all the stats, but it's a contender for largest.
The Byzantines have the big BC7-8 and BC9-10 under construction,
While Wilno has the Kepler class.
Rome is almost certainly building something very big and fast.
Japan is probably building a 29-30knot Yamato by now.


What do the Parthians know ?
For storyline purposes, I presume Parthian Naval intelligence can correctly find the Length, Beam, and number of barbettes of vessels still under construction. I actively try NOT to look at Jefgte's newer ships before I design mine, I need to have an idea of what he's doing, but it's only the older ships I should really know what their design specs are. Neither the BC7-8 nor BC9-10 would I really know what they are.

Orders to foundries can probably yield the approximate number and size of the barrels.  The speed can somewhat be inferred by the length and the freeboard when launched. Between launch and completion information on the final main and secondary batteries can be gleaned. The extent of the armored belt would be easy to determine. Financial information from armor foundries, bills of lading for rail transport, or simply bribing the right middle manager for a copy of what's been ordered - there are many ways to get an estimate of armor...but it's still interpretation.

The thickness of belt and deck armor, and the actual speeds of the vessel would be matters of interpretation. Many navies made official statements on these, but they may not be true. Speed trials can be run light or in a uncompleted state, or push the engineering tolerance, often all three. Examination of transit times should eventually allow an appreciation of the tactical speed. Knowing the dimensions, armaments, and speed will allow needed SHP and engine displacement to be appreciated. That will allow an approximate tonnage for belt and deck armor. Assumptions, informed by national practices, would allow estimates of tonnage to belt and deck. 

What does that all mean

Basically, they can make an educated estimate. In Friedman's book he deconstructs a battleship design and comes close to 'true'.  The USN tried to figure out Nelson's design, but did not expect the Brits had not gone with a raft-body floatation reserve, but shortened the citadel.

So, I do not expect Parthia Knows what the stats of the newest Byzantine ships are until a couple years after they are in service. The 1933 BC7 class is new (and has an error on TDS beam), we'd know what it looks like, and have an estimate of what it can do, but not the details. The same goes for the Aztec vessel, or the most recent Wilno, etc.  I looked at it when Tac posted it, nice ship, but I certainly don't remember the details enough to design "against" it.

It's really really big...but I would not know the exact BC, so tonnage would be close but not precise. The  4T2 18" guns. That's alarming. They class it as a BC, which means a big fast ship with battleship level armor. That's alarming. How fast? How thick the armor?...I don't know. The Byzantines have solid designs, they sometimes wind up with "better" ships on the same displacement as I do, though usually it's just a matter of different design choices.

Does it mean the Arwand class is outclassed? I would not know.
For a ship of roughly the same size, that's likely - as a BC - faster by 2-4 knots, with bigger guns, he's likely sacrificed a little armor somewhere - likely belt with the intention of fighting at ranges with more deck hits. The +3-4 knot speed is unlikely, our design studies for a 'fast' Arwand showed one would either need to be bigger or really need to cut back on armor - and a range fight design would not make sense  if the heavy deck armor was cut. So it's likely just 2 knots or so faster.

The Parthians can live with that. Between night, bad weather, and sea fog, as the time lag to get up to speed, we still think belt armor is important, but we don't scrimp on deck armor either. We've always assumed the foe will set the range, we just try to ensure there's no good range to pick.

While the two Wirozag were 26 knots to pair with the Stormbringer class in the Expeditionary fleet. An examination of battleline speeds found many nations first and second generation dreadnaughts were 25 and less knots. While 26 is not enough to ensure overtake, it is enough to ensure the Expeditionary Fleet can't be caught and defeated in detail.

With the Arwand the 26 knot speed was kept, expecting to advance the Parthian battleline speed to 26 knots. Future vessels were expected to be repeats of the Arwand with some modifications.

During the Arwand design process, larger vessels had been examined, but fewer larger vessels could be afforded. Further, defending against the 435mm gun was extremely difficult, requiring substantial armor applied in innovative ways. The larger guns being fielded make it worse. Coupled with the need to raise the deck level for floatation and excluding aerial bombs, and provide deep interior torpedo bulges backed by tonnage absorbing TDS, and much of the gains of more size were devoured by the armor needed for that size.


So...path forward
So my choices are ... build more Arwand trusting that they match up well to the 1-year later BC 7-8 and follow on BC 9-10, or "one up" to the next level and build an Aztec - level ship.

Guns, I will go with my 'Best' the 435L47 gun. 
I could use the 435L55, but it weighs a great deal more.
I don't want to wait 2 years to develop a third choice.

Armor becomes an issue.
Since hit rates at 25-30km are likely so low that ships can't actually sink each other without getting lucky, and most ships will be in their IZ from 20-25, the Parthians expect that for "finishing off", getting down to 15-20km will be likely.

Then there's the Night/Storm/island fighting/etc considerations.

The Arwand class aimed for an broadside right angle IZ of 15km-29km vs. own guns. Though the magazines were protected from 8+km.  It would be less now.

Parthia just finished the 1938 Naval Artillery, so improved shells and penetration are available.
The 435L47 shell is the same weight as the USN 16" mk8, but larger, so less penetration.
Still, I think looking at the USN's expectations for that- which NavWeaps covers well, gives a range.

Speed :
The Brits felt +2-3 knots would be needed to ensure you could catch and set the range.
We don't really deal with fouling as that's dealt with under maintenance.

26 knots is my new battleline.
28ish would make catching a 25-26knot doable, while being forcing others to field a 30-31knot to ensure catching.
30 knots, well we don't have any toys like that, who knows what we'd find out.

Size : A 'max hull' – max dock length, a BC of the beefiest US battleship, draft <10m, and massive beam...comes out about 54,000 tons. These were explored back in 1933 and passed up to build the cheaper Arwand but are now  updated.

So, I'll be posting 5 Battleship designs.
1 ) A 1937 update of Arwand, same 2T4 435mm, 26knots, armor improved.

2) A 1937 "Ardikkar / Warlike", a 10x435L47, 26knot battleship. This is the default choice. Fits with the 8 other 26 knot battlewagons, 10 big guns, and excellent armor.
The "Nevada" style gun arrangement because I dislike the KGV intensely.
should have something like (6x1.8)+(4x2) = ~18.8. Though the 17" guns might be 1.5 rpm rather than 2rpm, I haven't checked.

3) A 1937 "Ardikkar / Warlike", that does a very very unParthian thing and reduces the armor slightly.
This would be justified by actually counting the possible effects of sloping the armor and decapping. The other designs kinda view those as 'bonuses that are nice' which means the inner edge of the IZ is actually closer.  There is a strong possibility it would have a better IZ than whatever it faces. 12 x 435L47, 26 knots.  This is a contender. The 12 guns may be few, but is more 'Parthian'.

4) A 1937 "Ardikkar / Warlike", a 3TG3 435L47, 28knot battleship.  I actually rather like this as a decently balanced design, like the South Dakotas. But I am kinda trying to stay away from 3T3 designs in this game, as I've done that before. 3TG3 also have a slight ROF decline vs. TG2 or TG4. The loss of a barrel and turret does allow for slightly better armor, but the 10G version really has very good armor.

The 3TG3 arrangement traditionally had a slower feed rate for the middle gun, so the 3T3 gives 9x1.8 = 16.2rpm. So the 10gun arrangement is 16% higher ROF. The 12 gun would be about 50% more firepower.

5) A 1937 "Wad-girdag/ Whirlwind", an 2TG4 435L47, 30knot battleship.  It has 25% less firepower, but surprisingly I rather like it. Same armor as the 3T3 version, but the larger these vessels get the more concerned I am with the 2T4 arrangement. Theoretically there's more than enough armor on the guns and curved barbette, and 4TG turrets are extremely well developed in Parthia, there should be no problems.

Of course, the basic problem is I don't know what I'd DO with One or Two 30 knot battleships.
I can't see splitting my biggest, most powerful ships off into an independent squadron.  Ironically if I had been building fast battleships all along this would be less of an issue.   

There is still that enduring belief that one of the first casualties of battle damage is speed. One aerial torpedo, or underwater hit, and max speed may wind up at 20 knots.


All of which argues for the 26 or 28 knot designs, not the 30.
and the ROF favors the 8, 10 or 12 gun ships and not the 9 gun.
That is offset at range by time of flight – 1 rpm is more realistic to adjust for fall of shot.
However, if the Parthians are correct and ranges come down under 20km, then total ROF matters.