Parthian Empire

[Kaiser Kirk]

You are correct that you need the supporting vessels, the fleet should be an integrated grouping.
It's one of my vexations that despite starting from scratch, I'm not managing an even flow of ship classes.

While carriers should be in the mix, they are very dependent on their weapon system, and the airplane doesn't quite hit it's stride until the 1930s.
The experimental carriers were very important for evolving how to properly operate air groups as well. As attempted to be reflected in the Nav7 tech limits on carriers.

[TacCovert4]

Itll be a 1920s thing, but depending on the Rome/Aztec dynamic in the early 20s, I could see a shift to carriers by my navy.   It's Jeune Ecole and takes a view to trying to overcome the irretrievable deficit in capital ships by a revolutionary solution.  Probably falls about 50 percent flat as planes aren't there yet.  But it's not outside the realm of the possible.

[Kaiser Kirk]

One of the fun parts of all this is you can explore such concepts.

The interwar period lacked such battles so it's hard to say. I've got a book an US & Brit carrier development, and it was a slow learning curve. They have real strengths and weaknesses early on , and given how carrier ops slowly improved in the 1920s, combined with the aircraft and weather limitations, I'm not sure how well they'd work as independent raiders. However they might be an invaluable addition to a raiding group

I've long had the concept that a single 'big ship' with a couple mid sized and a bunch of small fast minimal ships would be the best raider assemblage. They could cover a great deal of sea, and could combine against convoys or counter raiders. A carrier in that mix multiplies that power.  Vastly improved Recon, and the ability to damage or cripple enemy fleet units in opposition.

I'm planning some carrier conversions as 'test', and then probably will build some in my 'armored cruiser' build slot in the late teens.
Given their vulnerability to counterstrike, I'm inclined to view the first batch as Rcn/Ftr platforms, make the error of "too small" carriers, and then go build some with more multirole capacity.

[Kaiser Kirk]

Oh, and for fun I modified Ihmulhu into a 16-gun version.
I decided to call it Kalifern as the California/Tennessee class are lovely ships. So this has the same bow. 

Without the mid-ships turret, I shortened her by 10m.
I also cut down the aft deck, but lengthened the forecastle.

Overall it came out a very tough ship.
The only real flaw is the Bahamuts are still slightly more efficient.

Kalifern, Parthian Battleship laid down 1916

Displacement:
   33,994 t light; 36,849 t standard; 39,598 t normal; 41,797 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (589.72 ft / 574.15 ft) x 111.55 ft (Bulges 121.39 ft) x (31.17 / 32.75 ft)
   (179.75 m / 175.00 m) x 34.00 m (Bulges 37.00 m)  x (9.50 / 9.98 m)

Armament:
      16 - 14.37" / 365 mm 45.0 cal guns - 1,496.34lbs / 678.73kg shells, 140 per gun
     Breech loading guns in turret on barbette mounts, 1916 Model
     4 x Quad mounts on centreline, evenly spread
      2 raised mounts
      8 - 5.12" / 130 mm 50.0 cal guns - 70.55lbs / 32.00kg shells, 250 per gun
     Quick firing guns in deck and hoist mounts, 1916 Model
     4 x Twin mounts on side ends, evenly spread
      12 - 5.12" / 130 mm 50.0 cal guns - 70.55lbs / 32.00kg shells, 200 per gun
     Quick firing guns in casemate mounts, 1916 Model
     12 x Single mounts on centreline, forward evenly spread
      12 hull mounts in casemates- Limited use in heavy seas
      6 - 3.54" / 90.0 mm 50.0 cal guns - 24.25lbs / 11.00kg shells, 350 per gun
     Anti-air guns in deck and hoist mounts, 1916 Model
     4 x Single mounts on sides, evenly spread
      4 raised mounts
     2 x Single mounts on centreline ends, evenly spread
      2 double raised mounts
      Weight of broadside 25,498 lbs / 11,566 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   13.8" / 350 mm   373.20 ft / 113.75 m   15.52 ft / 4.73 m
   Ends:   0.98" / 25 mm   200.92 ft / 61.24 m   13.12 ft / 4.00 m
   Upper:   3.54" / 90 mm   308.40 ft / 94.00 m   8.83 ft / 2.69 m
     Main Belt covers 100 % of normal length

   - Torpedo Bulkhead - Additional damage containing bulkheads:
      1.81" / 46 mm   373.20 ft / 113.75 m   34.84 ft / 10.62 m
   Beam between torpedo bulkheads 85.30 ft / 26.00 m

   - Hull Bulges:
      0.47" / 12 mm   373.20 ft / 113.75 m   22.97 ft / 7.00 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   15.7" / 400 mm   7.87" / 200 mm      13.8" / 350 mm
   2nd:   2.95" / 75 mm   1.38" / 35 mm      1.97" / 50 mm
   3rd:   3.54" / 90 mm   1.38" / 35 mm      2.56" / 65 mm
   4th:   0.31" / 8 mm         -         0.31" / 8 mm

   - Protected deck - multiple decks:
   For and Aft decks: 4.53" / 115 mm
   Forecastle: 1.18" / 30 mm  Quarter deck: 3.35" / 85 mm

   - Conning towers: Forward 13.78" / 350 mm, Aft 2.56" / 65 mm

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 4 shafts, 36,412 shp / 27,163 Kw = 20.00 kts
   Range 8,225nm at 14.00 kts
   Bunker at max displacement = 4,949 tons

Complement:
   1,403 - 1,824

Cost:
   £6.108 million / $24.431 million

Distribution of weights at normal displacement:
   Armament: 4,376 tons, 11.0 %
      - Guns: 4,376 tons, 11.0 %
   Armour: 13,016 tons, 32.9 %
      - Belts: 4,197 tons, 10.6 %
      - Torpedo bulkhead: 871 tons, 2.2 %
      - Bulges: 150 tons, 0.4 %
      - Armament: 3,666 tons, 9.3 %
      - Armour Deck: 3,723 tons, 9.4 %
      - Conning Towers: 409 tons, 1.0 %
   Machinery: 1,357 tons, 3.4 %
   Hull, fittings & equipment: 13,970 tons, 35.3 %
   Fuel, ammunition & stores: 5,604 tons, 14.2 %
   Miscellaneous weights: 1,276 tons, 3.2 %
      - Hull below water: 549 tons
      - Bulge void weights: 150 tons
      - On freeboard deck: 114 tons
      - Above deck: 463 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     51,932 lbs / 23,556 Kg = 35.0 x 14.4 " / 365 mm shells or 9.6 torpedoes
   Stability (Unstable if below 1.00): 1.22
   Metacentric height 8.5 ft / 2.6 m
   Roll period: 17.5 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.54
   Seaboat quality  (Average = 1.00): 1.27

Hull form characteristics:
   Hull has rise forward of midbreak,
     a ram bow and a cruiser stern
   Block coefficient (normal/deep): 0.638 / 0.641
   Length to Beam Ratio: 4.73 : 1
   'Natural speed' for length: 23.96 kts
   Power going to wave formation at top speed: 46 %
   Trim (Max stability = 0, Max steadiness = 100): 56
   Bow angle (Positive = bow angles forward): 22.00 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 %,  22.31 ft / 6.80 m,  20.67 ft / 6.30 m
      - Forward deck:   40.00 %,  20.67 ft / 6.30 m,  20.67 ft / 6.30 m
      - Aft deck:   25.00 %,  12.80 ft / 3.90 m,  12.80 ft / 3.90 m
      - Quarter deck:   15.00 %,  12.80 ft / 3.90 m,  13.12 ft / 4.00 m
      - Average freeboard:      17.68 ft / 5.39 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 89.2 %
      - Above water (accommodation/working, high = better): 116.2 %
   Waterplane Area: 48,524 Square feet or 4,508 Square metres
   Displacement factor (Displacement / loading): 100 %
   Structure weight / hull surface area: 242 lbs/sq ft or 1,183 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.94
      - Longitudinal: 1.77
      - Overall: 1.00
   Adequate 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

Kalifern
With Quad 365 instead of Triple 14"


Tapered belt from +2.7 to -2.5
2.7 to 1.5     200 -> 350     : 240,000+90,000
1.5 to -1.5      350                 : 1,050,000
-1.5 to -2.5   350-> 200     : 200,000+ 75,000
total : 1,655,000mm3
350mm ave = 4.73

Upper Belt :
From "B" to "Y", figure that's -10m at each end for not going to "A" and "X".
58m L x 3.6m H foreward, 36m L x 1.2m H aft, average height = 2.69m

Deck guns : 4 twin 130mm mounts on the decks are expected to supplement both end-on and broadside fire.

Casements : 6 guns each side seperated by 35mm armored screens, the hoists shielded by 65mm..
The casements are at +3.9m above water, 58m long.
Casement guns at each end, that leaves 4 in the middle spaced 11.6m apart.



TDS : Bulge, hull, liquid (18) void (18), liquid armored (30), Dam control, flooding (8)

438t Fire Control
25  LR Radio

25 kite balloon
34t Additional fire suppresion
25 Hulesmeyer device
25 Searchlight tower

34   Extra pumps
340 turbo electric
175 torpedo nets

4,949tons fuel oil at full load
Turbo electric range : 8225 x 1.15 = 9,458nm
Range at 20knots : 3214 x 1.15 = 3,696nm
Range at 18knots : 4305 x 1.15 = 4,905nm

4949


Decks

+6.3 Weather deck 30mm, top upper belt.
+3.9   Battery deck
          +2.7 top main belt
+1.5  Crown protective deck    80mm, top of TDS.
-1.0   Bottom edge protective deck
          -2.5 bottom main belt 
-3.5  2nd Deck
-6.0 1st Deck
-8.5 Engineering
-9.12 Double Bottom

[Kaiser Kirk]

Synopsis :
This is a long post, as I step through the conceptual process on conversions to transform two of my 'Torpedo boat carriers' into my first two seaplane carriers.

First there is my typical rambling, with bad graphics.

Then there is my breakdown of the costs

Finally is the converted vessel.

Stand by for rambling !
"Mus-Sag"
Refurbishments

Given the success of MTBs in several theaters, the old Parthian concept of bringing along a couple of flotillas with the fleet has seen it's adherents reinvigorated. At the same time, there is a desire to experiment with aircraft launching.

The 1894 Mus-sag was originally designed with carrying of the 32.5mx3m Series II torpedo boat.
Conceptually the torpedo boats would rest on deck cradels and be lowered down the sides. In order to ensure a clear deck for all this, deck-edge casemented guns were used and the barrels spaced so that the TBs could be lowered between.   

This means there is deck clear of barbettes and hoists, allowing an easy conversion to a clear deck.

The bow was raised for seakeeping, but the stern was flat, allowing storage there. Amidships, With 3m wide TBs, 4m of space on eachside was allowed, leaving an adequate but narrow 8m wide for the superstructure.

            |   |   |   |           on deck
  /           -  -   -   -
  \                       
            | - | - | - |  -      being lowered

Seaplane Carrier :
Based on the information for Argus,  4.6m of hanger height was provided.
Earlier seaplane conversions relied on temporary canvas hangers aft and a launch platform forward.
Given the clear desks of the Mus-Sag this appears a reasonable basis, but the raised forecastle would be an issue.

I don't like protective decks right on the water, but that was the period fashion.
Works great until you take on a little water.

Decks should be roughly :
7.49 - forecastle
5.05 - weather deck
2.65 - battery deck
0.25 - crown protective deck. This should also be the first continuous deck or strength deck.
-2.2   1st deck. Likely pierced for Engineering.
-5.75 Engineering
-6.00 Keel

Tearing the superstructure down to the 2.65m Battery deck, and then building upwards continous hull to the 7.49 forecastle level would give a hanger space 4.84m high, aka greater than Argus. The deck-edge casements would be retained and built around. Habitation would be in the lower hull.   
I'm thinking the superstructure would be built as a giant H *, with the two uprights including the stairs and funnels, while the flying bridges between had the command structure. In tunnel in the lower H would be the elevator. would allow seaplanes to be recovered at the stern, taken down in an elevator to the hanger for maintenance, or brought back up, and launched over the bow.

The layout echoes the early RN seaplane tenders. It doesn't allow for landings, but does turn the ships into reconnasiance platforms.

*Actually reading the Wiki article on HMS Argus, the H echoes their planned arrangement.

The superstructure/deck level changes fall under refurbishment – 25% cost.

Current Misc weight is :
Misc Weight :
140t - Torpedo Nets
48t -  Support for 480tons of TBs
128t - Torpedo Reloads ( 8TB x 2 torps x 2t = 4 full reserve loads)
256t - Fuel for TBs (4tx 8TB: 32, so 8 trips)

280t - Berthing for Crew of TBs

960t - 8 x 60t TB

48t - Cranes
25t - Long range radio
20t - (1905) fire control

17t – construction reserve.

OF THAT...
48+128+256+280+960+48 = 1720t is effectively dedicated to MTBs
Far more than strictly necessary.

For Aircraft it's 25t/AC or #AC^2 whichever is more.
So 1720/25 = 68.8  or sqrt/1720 = 41 planes
thats way more than this concept could fit ..

So...how big were float planes of that age?
A Sopwith Baby was 23 x 26ft,
and a Sopwith tabloid was 22 x 26ft.

Short patented folding wings in 1913, so in the 1910 tech they are being worked on and in the 1915 they have been learned.
For 1915

So I'm looking at rectangles roughly 7x8m on a hull that's 140m x 16m- but the 'citadel' is 93m.
There's casements,  the new upperworks could be flared a little, or wings can be clipped slightly....

I'm going to pretend a single line of floatplanes can be parked diagonally, left wing tip and tail to the hull, right tip
which would shorten how much space, and then floatplanes can be wheeled by.
To ensure that fits easily, there will be trolleys on tracks to shove them around.

So 93m, with A 2 meter gap between planes for access...call it 10m of 'length" for each plane, with 2 spaces free for the superstructure and elevator "foundations" 7 planes?

25 * 7 = 175t
The Parthians are going to double that for supplies, spare parts, etc.

So 350t...


the  original 1894 Single Expansion Engines are 19knts ,  2,196ts with 1467 bunkerage

While 2196 tons of 1915 Triple expansion gives 25.25 knots, I don't think they'd see the need. Conceptually these will hang out by the capital ships and launch planes, so keeping up with the battleline would be needed. Not more.

Converting this to 23knots Triple Compounds (to manuever around the fleet)
and 23% coal (¼ boilers use oil-sprayed coal), and 12knts cruise
Bunkers can hold 6850nm of fuel.

Guns:
Here, the Parthians would switch to the 165L43 QF.  While a smaller bore, the higher muzzle velocity means more kinetic energy concentrated on a smaller surface area...aka it has greater penetration.  The weapon fires faster for longer, and the cased ammunition is seen as safer to handle.

AA : Ditch the 60mm QF as the ranges have expanded beyond where they are useful, and add 90mm AA on the top of the H, 1 each corner.

They will need 24 t FC.

Armor :
The upper hull is currently protected by a 200ton, 50mm strake of armor intended to defeat HE shells.

Extending that up to the new flush deck increases this to 396 tons or +196ts.


COST CALCULATIONS
Reconstruction –
$1.8735   = 25% of $7.494    (based on original build cost)
0.749 BP = 10% of 7.49 BP   

Armanent and Machinery
234t new guns.
$0.468 = 2x tons/1000
0.234B = tons / 1000

867t new engines
$1.734 = 2x tons/1000
0.867 B = ton/1000

Armor and functional misc weight
+196t upper belt

$0.196 = equal BP
0.196 BP = ton/1000

+350t AC
+24t FC

$0.374 = equal BP
0.374 BP = ton/1000

Hull fittings and Equipment
N/A

Fuel, Ammunition & stores, non-functional miscweight.

Fuel 1459 oil & coal
$0.7295  = 1459/2000
0 BP  = No BP cost

Total :
$2.42   = $2.421   
2.24 BP = 2.224 BP 

Mus-sag R1915, Parthian Torpedo Boat Seaplane Carrier laid down 1894 (Engine 1915)

Displacement:
   7,499 t light; 7,828 t standard; 8,638 t normal; 9,287 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (464.54 ft / 459.32 ft) x 52.49 ft x (19.69 / 20.93 ft)
   (141.59 m / 140.00 m) x 16.00 m  x (6.00 / 6.38 m)

Armament:
      8 - 6.50" / 165 mm 43.0 cal guns - 143.30lbs / 65.00kg shells, 220 per gun
     Quick firing guns in casemate mounts, 1914 Model
     8 x Single mounts on sides, evenly spread
      8 hull mounts in casemates- Limited use in heavy seas
      4 - 3.54" / 90.0 mm 50.0 cal guns - 24.25lbs / 11.00kg shells, 300 per gun
     Anti-air guns in deck and hoist mounts, 1912 Model
     4 x Single mounts on sides, evenly spread
      Weight of broadside 1,243 lbs / 564 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   1.97" / 50 mm   305.12 ft / 93.00 m   9.84 ft / 3.00 m
   Ends:   1.97" / 50 mm   154.17 ft / 46.99 m   8.20 ft / 2.50 m
   Upper:   1.97" / 50 mm   301.84 ft / 92.00 m   15.88 ft / 4.84 m
     Main Belt covers 102 % 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:   1.97" / 50 mm         -               -

   - Armoured deck - single deck:
   For and Aft decks: 0.98" / 25 mm
   Forecastle: 0.79" / 20 mm  Quarter deck: 0.79" / 20 mm

   - Conning towers: Forward 1.97" / 50 mm, Aft 0.00" / 0 mm

Machinery:
   Coal and oil fired boilers, complex reciprocating steam engines,
   Direct drive, 2 shafts, 14,239 ihp / 10,622 Kw = 20.00 kts
   Range 6,850nm at 12.00 kts
   Bunker at max displacement = 1,459 tons (23% coal)

Complement:
   447 - 582

Cost:
   £0.442 million / $1.769 million

Distribution of weights at normal displacement:
   Armament: 203 tons, 2.3 %
      - Guns: 203 tons, 2.3 %
   Armour: 1,107 tons, 12.8 %
      - Belts: 736 tons, 8.5 %
      - Armament: 31 tons, 0.4 %
      - Armour Deck: 322 tons, 3.7 %
      - Conning Tower: 18 tons, 0.2 %
   Machinery: 867 tons, 10.0 %
   Hull, fittings & equipment: 4,756 tons, 55.1 %
   Fuel, ammunition & stores: 1,139 tons, 13.2 %
   Miscellaneous weights: 566 tons, 6.6 %
      - Hull below water: 140 tons
      - Hull void weights: 17 tons
      - On freeboard deck: 350 tons
      - Above deck: 59 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     26,397 lbs / 11,973 Kg = 192.6 x 6.5 " / 165 mm shells or 3.9 torpedoes
   Stability (Unstable if below 1.00): 1.14
   Metacentric height 2.4 ft / 0.7 m
   Roll period: 14.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.25
   Seaboat quality  (Average = 1.00): 2.00

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.637 / 0.644
   Length to Beam Ratio: 8.75 : 1
   'Natural speed' for length: 21.43 kts
   Power going to wave formation at top speed: 44 %
   Trim (Max stability = 0, Max steadiness = 100): 25
   Bow angle (Positive = bow angles forward): 12.00 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 %,  24.57 ft / 7.49 m,  24.57 ft / 7.49 m
      - Forward deck:   30.00 %,  24.57 ft / 7.49 m,  24.57 ft / 7.49 m
      - Aft deck:   35.00 %,  24.57 ft / 7.49 m,  24.57 ft / 7.49 m
      - Quarter deck:   15.00 %,  24.57 ft / 7.49 m,  24.57 ft / 7.49 m
      - Average freeboard:      24.57 ft / 7.49 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 43.3 %
      - Above water (accommodation/working, high = better): 191.1 %
   Waterplane Area: 18,251 Square feet or 1,696 Square metres
   Displacement factor (Displacement / loading): 218 %
   Structure weight / hull surface area: 136 lbs/sq ft or 663 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 1.47
      - Longitudinal: 6.11
      - Overall: 1.70
   Excellent machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

In the end, I spend $4.84 and 4.48BP to get a pair of experimental Seaplane carriers with a total of 14 seaplanes.
Which actually works out a reasonable deal I think.

[Kaiser Kirk]

Snip,
I'm going to ask you to glance at the reconstruction above, compared to the reconstruction rules,
and let me know if I screwed something up, or something is not 'working as intended'.

In particular, going from reciprocating to turbine specifically needs electric drive.
here I'm going reciprocating (simple) to reciprocating (compound)...so I should not need electric drive...as I understand.

Also...where are the aircraft rules hidden?
I went and pulled up the springstyle notes they are sourced from and then tried to rein in the possible airgroup with logic.