Parthian vessels 1937 - 1940

[Jefgte]

There is a certain shocked state of denial when you move to File, skim down to the one below "Save data file" and accidentally click "Clear all" on one's just finalized potential carrier....

You must redone immediately or very soon after... Datas are still fresh in the mind.

[Kaiser Kirk]

I have now.
But it generated a question about the Deck Park tech, so I've put that in the future tech thread for discussion.

[Kaiser Kirk]

So the question on deck parks I put here :  Deck Parks

stems from my work on this ship - the Afson class Flight Deck Carrier.
That was the vessel I had finished my 'final' version of and then clicked "clear all".
Curiously, while I swiftly reconstructed it, the weights were off by ~5tons.

For it I've allocated 20% (10 planes) as an "early" deck park, but I could easily reduce that (15% = 8 planes) and move the 190 tonnage to misc reserve or add some armor. I've classed those 2 planes as 'mail planes' so they don't really matter offensively.

The reason for this class rather than replicating the "Burning Bow" is complex.
The "Burning Bow" has been in service a year, and while designed pre-naval monoplane, is the first to host naval monoplanes.

Meanwhile carrier operations continue to evolve, now involving spotting large groups of planes on the aft of the flight deck for rapid take off. The "lead" plan must have sufficient runway room to liftoff, limiting the area of flight deck usable for spotting.

The improvement in operations coincides with the growth of carrier decks and the aggressive cantilevering of width, allowing landing of planes while some are on deck, providing the possibility of a deck park.

Further, it is among the first vessels to mount a naval RADAR facility. For Carriers, early long range detection of incoming attackers, even if currently unreliable.

These considerations make having a flying off deck to allow emergency launch of fighters regardless of if operations allow the main flight deck to be used as well..not as critical.  Further, reclaiming that deck length means the "lead" plane of a spotted group can be placed further forward, increasing the number of planes that can be spotted.  These also helps ensure the newer planes will have takeoff and landing room.

This combination of factors has also made the Parthians reconsider relying on their 190m docks for Carriers. They have a limited number of 235m docks, and want to keep at least 1 at Home, Atlantic and Pacific theaters clear for emergency repairs or refits of any class. The newest battleships are taking up two, leaving only 1 for this carrier class. 

If needed, more drydocks can be built, but that may wait until the Parthians have developed a better idea of desired parameters, as they concede even longer may be needed. Total displacement of carrier has skyrocketed, which is viewed as concerning as they seem somewhat vulnerable.

Afson "Incantation"  VII, Parthia Fleet Carrier laid down 1937

Displacement:
    24,500 t light; 25,493 t standard; 28,336 t normal; 30,610 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
    (767.43 ft / 754.59 ft) x 82.02 ft x (27.72 / 29.47 ft)
    (233.91 m / 230.00 m) x 25.00 m  x (8.45 / 8.98 m)

Armament:
      24 - 4.53" / 115 mm 47.0 cal guns - 55.12lbs / 25.00kg shells, 420 per gun
      Dual purpose guns in deck and hoist mounts, 1930 Model
      8 x 2-gun mounts on centreline ends, evenly spread
      4 x 2-gun mounts on sides, forward deck aft
        2 raised mounts - superfiring
      24 - 1.46" / 37.0 mm 70.0 cal guns - 1.72lbs / 0.78kg shells, 3,200 per gun
      Anti-air guns in deck and hoist mounts, 1929 Model
      6 x 2 row quad mounts on sides, evenly spread
      36 - 0.91" / 23.0 mm 90.0 cal guns - 0.44lbs / 0.20kg shells, 5,000 per gun
      Anti-air guns in deck mounts, 1929 Model
      10 x Twin mounts on side ends, majority forward
      8 x Twin mounts layout not set
        4 double raised mounts
      Weight of broadside 1,380 lbs / 626 kg

Armour:
  - Belts:        Width (max)    Length (avg)        Height (avg)
    Main:    2.95" / 75 mm    490.49 ft / 149.50 m    16.99 ft / 5.18 m
    Ends:    0.98" / 25 mm    264.07 ft / 80.49 m    12.01 ft / 3.66 m
      Main Belt covers 100 % of normal length
      Main Belt inclined -15.00 degrees (positive = in)

  - Torpedo Bulkhead - Additional damage containing bulkheads:
        2.24" / 57 mm    490.49 ft / 149.50 m    28.74 ft / 8.76 m
    Beam between torpedo bulkheads 59.06 ft / 18.00 m

  - 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:    1.38" / 35 mm    1.38" / 35 mm        1.38" / 35 mm
    2nd:    0.59" / 15 mm          -                  -
    3rd:    0.31" / 8 mm          -                  -

  - Armoured deck - single deck:
    For and Aft decks: 3.15" / 80 mm
    Forecastle: 1.38" / 35 mm  Quarter deck: 2.56" / 65 mm

  - Conning towers: Forward 3.54" / 90 mm, Aft 0.00" / 0 mm

Machinery:
    Oil fired boilers, steam turbines,
    Geared drive, 3 shafts, 141,871 shp / 105,836 Kw = 32.00 kts
    Range 8,164nm at 18.00 kts
    Bunker at max displacement = 5,117 tons

Complement:
    1,091 - 1,419

Cost:
    £8.377 million / $33.507 million

Distribution of weights at normal displacement:
    Armament: 383 tons, 1.4 %
      - Guns: 383 tons, 1.4 %
    Armour: 5,010 tons, 17.7 %
      - Belts: 1,141 tons, 4.0 %
      - Torpedo bulkhead: 1,170 tons, 4.1 %
      - Armament: 139 tons, 0.5 %
      - Armour Deck: 2,488 tons, 8.8 %
      - Conning Tower: 71 tons, 0.3 %
    Machinery: 3,932 tons, 13.9 %
    Hull, fittings & equipment: 8,499 tons, 30.0 %
    Fuel, ammunition & stores: 3,836 tons, 13.5 %
    Miscellaneous weights: 6,676 tons, 23.6 %
      - Hull below water: 2,671 tons
      - Hull void weights: 121 tons
      - Hull above water: 2,640 tons
      - On freeboard deck: 1,000 tons
      - Above deck: 244 tons

Overall survivability and seakeeping ability:
    Survivability (Non-critical penetrating hits needed to sink ship):
      51,920 lbs / 23,550 Kg = 1,118.8 x 4.5 " / 115 mm shells or 6.9 torpedoes
    Stability (Unstable if below 1.00): 1.26
    Metacentric height 5.6 ft / 1.7 m
    Roll period: 14.5 seconds
    Steadiness    - As gun platform (Average = 50 %): 70 %
            - Recoil effect (Restricted arc if above 1.00): 0.14
    Seaboat quality  (Average = 1.00): 1.67

Hull form characteristics:
    Hull has a flush deck,
      a ram bow and small transom stern
    Block coefficient (normal/deep): 0.578 / 0.587
    Length to Beam Ratio: 9.20 : 1
    'Natural speed' for length: 29.44 kts
    Power going to wave formation at top speed: 54 %
    Trim (Max stability = 0, Max steadiness = 100): 42
    Bow angle (Positive = bow angles forward): 12.00 degrees
    Stern overhang: 6.56 ft / 2.00 m
    Freeboard (% = length of deck as a percentage of waterline length):
                Fore end,    Aft end
      - Forecastle:    20.00 %,  29.53 ft / 9.00 m,  29.53 ft / 9.00 m
      - Forward deck:    30.00 %,  29.53 ft / 9.00 m,  29.53 ft / 9.00 m
      - Aft deck:    35.00 %,  29.53 ft / 9.00 m,  29.53 ft / 9.00 m
      - Quarter deck:    15.00 %,  29.53 ft / 9.00 m,  29.53 ft / 9.00 m
      - Average freeboard:        29.53 ft / 9.00 m
    Ship tends to be wet forward

Ship space, strength and comments:
    Space    - Hull below water (magazines/engines, low = better): 99.5 %
        - Above water (accommodation/working, high = better): 234.3 %
    Waterplane Area: 45,454 Square feet or 4,223 Square metres
    Displacement factor (Displacement / loading): 136 %
    Structure weight / hull surface area: 119 lbs/sq ft or 579 Kg/sq metre
    Hull strength (Relative):
        - Cross-sectional: 0.95
        - Longitudinal: 1.58
        - Overall: 1.00
    Adequate machinery, storage, compartmentation space
    Excellent 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

An flight deck carrier meant to either part of fleet defense or be part of a separate high speed strike element, working with cruisers and armored cruisers.

Incantation - Afson
Magician  - Kundag
Sorcerer - Jadug
Magic  - Kundagih
Sorcery - Jadugih
Magus - Moymard
Spell - Marig

Air group

Early Deck Park : 10
1 flight Ftr 8
Mail planes 2

Hanger : 52
1 Sqd Ftr 16
1 Sqd Ftr/Div 16
1 Sqd Torp/Rec 16
1 Lance Torp 4

Hanger Calculations :
4223 / 77 = 54.84

54 * 95 = 5130 = (2565 / 2565)

Early Deck Park : Not defined, est 10% of single hanger.
10 * 95 = 950

Control Tower
One tower, on the starboard side is fitted.
The tower is designed to be as smooth as possible
so as not to disrupt air flow.

Guns
As the historical British carriers, two mounts are mounted on each corner of the deck, for a total of 8.

In true Parthian form, they then follow the American practice of two-gun mounts for and aft of the tower. For 4 more.

The 37mm and 23mm alternate down the sides of the deck,
and each side of the tower has 1 twin 23mm on each face at each level.


Armor

The Hanger deck floor is the top of the armor system.
That serves as the main armor deck, with a splinter deck below.
All hatches are in the form of vertical risers flanking the space, with
a substantial lip. The hanger deck is slightly crowned, with drain holes leading through the hanger walls, to allow fluid spills to be hosed to the exterior of the vessel.

The main armor belt covers from the hanger deck down to -1.5m.
The lower portion is backed by both a protective deck and TDS, to
ensure bomb and torpedo stores are protected.

Belt
2 Deck levels (5.0m) high
outsloped 15 degrees
5/cos(15) = 5.17638 = 5.18

TDS rises behind belt, above WL to seal to protective deck at +1m.

Waterline protection :
75mm inclined + 25mm protective deck + 57mm TDS
75 + ((25*1.5)/2)+(57/2) = 122+ incline

armor Decks
Hanger Deck floor is 50mm and caps main armor belt.
A protective deck at 25mm covers from +1 to -1.5m.

Vert pen : 67mm

End Belt Fore : Protective deck 50 flats / 85 slopes
End Belt Stern : Protective Deck 75 flates /110 slopes


Miscellaneous Weight
121t - Reserve

AD
39t  - Fire Control 1930
25t -  Long Range Radio
0t  -  SR Radio
10t -  SR Radio - Deck Operations
10t -  SR Radio - CAG
10t -  Radio Jammer
25t - Air Search Radar
25t - Hulesmeyer device
25t - Night Fighting (& landing aids) Gear
50t -  Squadron Assembly Room.
25t - Vessel Ventilation, intakes

OD
950t - Ealy deck park - Provisions for 10 aircraft
5t  - Paravanes
25t - Vessel Ventilation
20t - 2 x Steam catapults


HAW
2565t - Provisions for 27 Aircraft
25t Additional Fire Extinguishers
25t Hanger Ventilation
25t Vessel Ventilation

HBW
2565t - Provisions for 27 Aircraft
25t Hanger Ventilation
25t  Extra Pumps
25t  Extra Fire Ext
31t  Aux Diesel Generator 1000kw - 164nm of fuel.

Decks
+9  Flight Deck
+3.5    Hanger Deck, upper armor deck, Top main belt
+1.0    Main Armor Deck, Top TDS
-1.5      2nd Platform Deck, bottom main belt
-4.0      1st Platform Deck
-6.6      Engineering
-7.62    Double Bottom
- 8.33    Keel

[Jefgte]

I always thought your 188m CVs were too short.

Since 1932, Byzantium, having observed the evolution of aviation, has been building in 225m dry docks.
Regarding hangar heights, I considered, with the first CVs,
two 2.44m decks => 4.88m available.

I also note a speed of 32 knots, better for taking off heavier aircraft, and lighter armor for reasonable displacement.

[Kaiser Kirk]

They are from a WWII perspective, which I think influences most folks.

With monoplanes, you can definitely fly from shorter decks, but it does limit how much strike ability you can generate in one launch, which as the tech is allowing larger and larger launches makes a difference. 

But the goals of Parthian aircraft carriers have mainly been to put fighters up to deny the other side reconn/spotting/strike - which is quite doable on those shorter decks. Indeed I called the earlier 160m ones 'Fighter Carriers' and modeled them on HMS Hermes/ USS Commencement Bay.  The main problem is now they are slow, but I can restrict them to tailing the battleline and they will ensure fighter cover while letting the larger carriers roam.

The 190m ones should be able to launch small strike groups, but I generally assumed that the low numbers of strike aircraft one could fly off in that time period were not sufficient to do much more than nuisance damage, and attrition would rapidly eliminate the strike groups. But they should be able to sustain the fighter aspect, which will mean there's a platform for the next batch of strike aircraft to fly from.

The last carriers the 'Burning Bow' and 'Barkusc' were designed during the Biplane time, with some strike ability to wound/slow down the enemy forces. This one is looking at being more strike oriented and is after monoplanes are in service, so you're seeing that shift now. The 32knot speed is an acknowledgement that it may steam with my 32knot ACs on a strike.