The Socialist Republic of Sieran

[denodon]

Thanks for the article, I'll have a read through on the train home. The two major issues I've come up with with this scout carrier design is the need for anti icing/de icing to keep operations running in common conditions and the need to have an enclosed hull and low height to reduce topweight and increase stability yet also need to provide for the hangar a means of venting fumes outside to prevent dangerous conditions building up within.

[denodon]

Some of you perhaps might be interested in seeing my process in producing AU designs. There are a variety of methods I use however Collaging is by far the most useful. I use the collaging process when experimenting with various aesthetics and designs before actually beginning to draw an image from scratch. After producing a springsharp report or a series of specifications and role requirements, I use a variety of images I have saved on my HDD to build a number of collage What-Ifs to get a tangible sense of how the final drawing may look before I start it. This helps pick out design flaws and issues before I've started doing too much work on producing the end result.



In this example, I have done a collage to get an idea of how the Scout Carrier may look whilst fitting the size and requirements needed by the role. Initially I started with the Hermes and scaled it up some before overlapping the Victorious bow and stern over it to bring the design of the carrier forwards to the late 30s period in appearance. I replaced the Hermes island with that from the Unryu and attached to this the Victorious funnel with the cap from my cruisers. The mast and crane also come from the cruiser. The air wing from the SRN Lazerev and indeed the entire ship was copied over into the file to compare the two designs to see how they matched up to scale and again see if the aesthetic and features were somewhat common between the two designs.

From here I will take this collage as a guide and then completely redraw it to Sieranian standards, keeping only the basic overall shape of the original but replacing things such as the guns, boats, etc with more suitable versions. Sure it takes more time this way but I prefer to draw things myself rather than kitbash in final drawings so the collage is only a guide.

Any thoughts, comments or questions on the process or the design? I'm somewhat happy with this overall layout. Matches my idea of what a Sieranian carrier should look like.

In terms of the actual carriers design, that information from Operation Frostbite seems to indicate that provided you have the right equipment, operations should still be possible. Sieranian aircraft are kept within the hangar until shortly before launch to minimize the exposure time to the environment, hence a 30 aircraft airwing would likely make sense here as I think all the aircraft could fit into the hangar.

[denodon]

Well here is a quick springsharp for the above carrier design. I have added misc weight to cover the air wing and flight deck however I am not certain if I need to add more to adequately cover the weight of the hangar atop of the hull (not sure how Springsharp handles this). Armament and Armour is provisional. Range is identical to the Rozhestvensky class and machinery for these two carriers comes from a cancelled one of those cruisers, each carrier receiving half of the turbines and boilers only coupled to a geared drive instead of turbo generators to save weight and cost.

Of course Springsharp is not ordinarily used for simming carriers however I used a reference guide to produce a rough idea. I am undecided as yet as to whether I should have a single squadron of each for fighters, scout bombers and patrol aircraft, double the fighter squadrons and keep one of scout bombers or keeping the current listed arrangement. It's also worth keeping in mind that the TB-31 whilst being a scout bomber/torpedo bomber was also adapted to the role of a long range fighter. Sure they would not be able to compare with a zero but they still provide some additional capability for escorting strike aircraft and keeping the high performance fighters in the CAP or over the main fleet.

Code: Select all

Design A1, Socialist Republic of Sieran Scout Aircraft Carrier laid down 1939

Displacement:
	9,780 t light; 10,103 t standard; 11,739 t normal; 13,047 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
	(632.50 ft / 622.50 ft) x 60.00 ft x (20.00 / 21.69 ft)
	(192.78 m / 189.74 m) x 18.29 m  x (6.10 / 6.61 m)

Air Wing:
      9 (7 Assembled) - Interceptor/Fighters
      18 (14 Assembled) - Scout Bombers
      3 - Long range patrol aircraft
      = 30 Aircraft total, 24 Operational


Armament:
      8 - 4.70" / 119 mm 45.0 cal guns - 52.35lbs / 23.75kg shells, 300 per gun
	  Dual purpose guns in deck mounts, 1939 Model
	  8 x Single mounts on sides, evenly spread
      16 - 1.57" / 40.0 mm 45.0 cal guns - 1.97lbs / 0.89kg shells, 800 per gun
	  Anti-air guns in deck mounts, 1939 Model
	  8 x Twin mounts on sides, evenly spread
		2 raised mounts
      24 - 0.79" / 20.0 mm 45.0 cal guns - 0.25lbs / 0.11kg shells, 1,500 per gun
	  Anti-air guns in deck mounts, 1939 Model
	  12 x Twin mounts on sides, evenly spread
		4 raised mounts
      Weight of broadside 456 lbs / 207 kg

Armour:
   - Belts:		Width (max)	Length (avg)		Height (avg)
	Main:	2.00" / 51 mm	250.00 ft / 76.20 m	9.30 ft / 2.83 m
	Ends:	Unarmoured
	  Main Belt covers 62 % of normal length

   - Torpedo Bulkhead - Additional damage containing bulkheads:
		3.00" / 76 mm	404.63 ft / 123.33 m	18.36 ft / 5.60 m
	Beam between torpedo bulkheads 50.00 ft / 15.24 m

   - Gun armour:	Face (max)	Other gunhouse (avg)	Barbette/hoist (max)
	Main:	0.50" / 13 mm	      -			      -

   - Armoured deck - multiple decks:
	For and Aft decks: 2.00" / 51 mm

Machinery:
	Oil fired boilers, steam turbines, 
	Geared drive, 2 shafts, 57,501 shp / 42,896 Kw = 29.22 kts
	Range 8,000nm at 18.00 kts
	Bunker at max displacement = 2,944 tons

Complement:
	563 - 733

Cost:
	£3.391 million / $13.564 million

Distribution of weights at normal displacement:
	Armament: 87 tons, 0.7 %
	   - Guns: 87 tons, 0.7 %
	Armour: 1,866 tons, 15.9 %
	   - Belts: 208 tons, 1.8 %
	   - Torpedo bulkhead: 825 tons, 7.0 %
	   - Armament: 10 tons, 0.1 %
	   - Armour Deck: 824 tons, 7.0 %
	Machinery: 1,556 tons, 13.3 %
	Hull, fittings & equipment: 4,271 tons, 36.4 %
	Fuel, ammunition & stores: 1,959 tons, 16.7 %
	Miscellaneous weights: 2,000 tons, 17.0 %
	   - Hull above water: 500 tons
	   - On freeboard deck: 1,000 tons (25t allocated per aircraft + additional margin for equipment)
	   - Above deck: 500 tons (Radar equipment, cranes, etc)

Overall survivability and seakeeping ability:
	Survivability (Non-critical penetrating hits needed to sink ship):
	  26,666 lbs / 12,096 Kg = 513.7 x 4.7 " / 119 mm shells or 5.4 torpedoes
	Stability (Unstable if below 1.00): 1.10
	Metacentric height 2.8 ft / 0.9 m
	Roll period: 15.1 seconds
	Steadiness	- As gun platform (Average = 50 %): 66 %
			- Recoil effect (Restricted arc if above 1.00): 0.06
	Seaboat quality  (Average = 1.00): 1.32

Hull form characteristics:
	Hull has raised forecastle,
	  a normal bow and large transom stern
	Block coefficient (normal/deep): 0.550 / 0.564
	Length to Beam Ratio: 10.38 : 1
	'Natural speed' for length: 28.24 kts
	Power going to wave formation at top speed: 51 %
	Trim (Max stability = 0, Max steadiness = 100): 50
	Bow angle (Positive = bow angles forward): 12.00 degrees
	Stern overhang: 5.00 ft / 1.52 m
	Freeboard (% = length of deck as a percentage of waterline length):
				Fore end,	 Aft end
	   - Forecastle:	20.00 %,  23.50 ft / 7.16 m,  20.50 ft / 6.25 m
	   - Forward deck:	30.00 %,  18.50 ft / 5.64 m,  18.50 ft / 5.64 m
	   - Aft deck:	35.00 %,  18.50 ft / 5.64 m,  18.50 ft / 5.64 m
	   - Quarter deck:	15.00 %,  18.50 ft / 5.64 m,  18.50 ft / 5.64 m
	   - Average freeboard:		19.14 ft / 5.83 m
	Ship tends to be wet forward

Ship space, strength and comments:
	Space	- Hull below water (magazines/engines, low = better): 61.6 %
		- Above water (accommodation/working, high = better): 169.9 %
	Waterplane Area: 27,137 Square feet or 2,521 Square metres
	Displacement factor (Displacement / loading): 163 %
	Structure weight / hull surface area: 105 lbs/sq ft or 511 Kg/sq metre
	Hull strength (Relative):
		- Cross-sectional: 1.22
		- Longitudinal: 1.24
		- Overall: 1.23
	Excellent machinery, storage, compartmentation space
	Excellent accommodation and workspace room
	Good seaboat, rides out heavy weather easily

[odysseus1980]

Seems good!

[denodon]

Thanks.
I've been thinking more about the air group and leaning more towards 18 fighters split into two squadrons (one for CAP, one for escort and limited bombing duty) then a squadron of 9 scout bombers equipped with torpedoes available for use once an enemy is spotted/has already been located.
Torpedoes are more effective at sinking ships than bombs and given the limited air wing available, torpedo bombers being used to supplement the long range patrol aircraft might work best for the intended role of the carriers.
In this case, the TB-31 whilst designed as a torpedo bomber was also able to be used to a limited extent as a dive bomber. It had decent range as well so scouting was possible.

[eswube]

That's an interesting addition, and thanks for showing us Your design method.
As for the air group - note that until around middle of war it was more typical to have around squadron each of fighters, dive bombers and torpedo bombers (btw. it seems that if capabilities were combined in single airframe, it was rather dive bomber + scout (Dauntless), rather than torpedo + scout), and only late in the war it was more and more often 2-3 x fighters, 1 (2) x strike aircraft - when modern fighters (like Hellcat or Corsair) become truly capable of being dual-role (fighter and attack).
Of course, considering that You have both limited economical capacity, and limited size of carriers, multi-role strike-recce aircraft might be in a way a necessity, though I'm unsure how effective such dive/torpedo bomber could actually be (given the constraints of late 1930s technology).

[denodon]

Yeah I agree about the difficulty faced by multi role types however outside of the USN and IJN there were a few, both purpose built and modified designs such as the Stukas modified for the GZ and the Fairey Barracuda.
Another example actually is the Fairey Albacore, considered perfectly capable of dive bombing and used for such despite its designed torpedo bombing/scout role. Such a design is also about the right time period for Sieran however it is likely to be a monoplane with slightly more power.

In the case of the TB-31s replacement of around 1940 or so the torpedo and scout roles take priority with longer range achieved via improved aerodynamics and carrying the weapons load semi-recessed. Localised strengthening would allow for limited dive bombing capability (around 50 degrees or so) which would also allow the aircraft to follow an approach similar to that the RN used for torpedo bombers; entering a dive close to the target and pulling out just above the surface to deliver the torpedo, reducing the time spent in the vulnerable low level position.

In terms of armament, the aircrafts defensive weapons would be reduced from the TB-31 I'm thinking to a single rear firing 20mm and another firing forward in the wing. Offensive armament would be either a single torpedo or 1000lb bomb under the fuselage or 2x 500lb bombs under the wings. A single 500lb bomb under the fuselage would allow for max fuel to be carried which would likely be the configuration of the bombers when used for scouting.

[Bombhead]

That's certainly an interesting way to design a carrier.

[denodon]

Not the carrier but here is another collage this time for the TSB (Torpedo-Scout-Bomber) aircraft, first flown end of 1940 and entering service in 1942 just as the war starts. Akin to the Avenger it has an internal bomb bay for the torpedo and hardpoints under the folding wings for bombs. It is compared to the TB-31 which it will be replacing. Main changes are the slightly reduced firepower but much increased engine power. Performance is improved by refined aerodynamics and the internal carriage of the main drag inducing weapon. Fuel load is also increased as per the scout role.

I don't have final stats for the design now however I do know that like the TB-31 it will be a 3 crew aircraft, all under the extended canopy. The plane is probably about the same size as the TB-31, perhaps larger.

Any thoughts/questions/ideas?

[Rodondo]

Just an idea but maybe a few water cannons/hose outlets up on deck, around the island and have a small water heating plant to help provide hot water to wash the decks free of snow and ice? Also help reduce corrosion from salt spray which IIRC the Bering can serve easily