The Socialist Republic of Sieran

[denodon]

I'm curious if anybody would be interested in seeing some developmental designs much like the proposals made by designers to the Naval Committee and shipyards for evaluation?

I'm thinking such a thing would be a good way of showing how early on Sierans designers had poor knowledge of ship design but gradually improved with outside assistance.

[Raxar]

Sounds interesting, go for it!

[eltf177]

I would as well. Not every design works, but you learn from your failures...

[Raxar]

I would as well. Not every design works, but you learn from your failures...

Exactly.

[denodon]

WIP of Sieran's latest (and second) aircraft carrier design, currently known only as the Project A Class 'Scout Carrier'.



Experience with the SRN Lazarev (posted previously) prooved that a larger carrier that could keep up with the fleet was required. Current Carrier doctrine dictates that these Air Support vessels remain in position behind the battleship and cruiser line providing air cover for the gunships from the projected enemy (The Imperial Japanese Navy and its aircraft).
Aircraft have yet to prove themselves in terms of offensive capabilities to the Naval planners of the SRN so the ships, despite their Dive bomber and torpedo bombers squadrons, are considered predominantly as taking up secondary importance to the big guns and as such have a heavy fighter complement.

Any feedback is most welcome as I'm trying to develop this design. I'm aiming for a 14,000-18,000 tonne carrier with a speed of about 28 knots. I'm also debating whether a hybrid of British and American carrier design in term of hangar location and armor protection might work.
Also, the ships hulls are based upon the design of a cancelled heavy cruiser design (which I shall draw afterwards).

[denodon]

Now I know this is not shipbucket style but it is relevant to this AU; The Korolev TB-31 Torpedo Bomber. (Image represents the TB-31A-2 model)



The Korolev TB-31(named 'Grubyjhouk' after the Rough-legged Buzzard) was the standard shipborne torpedo bomber of the Sieranian Fleet Air Arm from its entry into service in 1937 until well after the second world war. Upon its entry into service it was one of the fastest and most rugged of carrier aircraft then in existence though it was for much of its early years handicapped by under performing engines.
Although primarily used as a carrier-based aircraft, it was also used as a land-based bomber upon occasion. The TB-31 had a crew of three: pilot, navigator/radio operator and dorsal gunner.

Design and development

The TB-31 was designed to a 1934 specification for a new metal monoplane torpedo bomber to replace the aging and outdated Korolev TB-23 biplane for use on the nations current and future Aircraft Carriers. It successfully competed against the SAF TB-29 for the production contract and first flew in October 1936.

Testing of the aircraft revealed few flaws with the overall design other than an unusual cockpit gauge layout and sluggish response from the early model Movich MSh-190 radial engine. The initial prototype lacked the specifications dorsal turret due to lack of availability in time for the completion deadline. As a result, the first prototype instead had a dummy aerodynamic fairing fitted to the rear cockpit to simulate the location and weight of the turret. Later prototypes and production models were fitted with originally twin-gun turrets which were upgraded in the TB-31C-2 with quad-guns.

At the time of development, the Navy was comparing both inline and radial engine configurations for their future aircraft. The Navy preferred the Radial engine for its ease of maintenance and reliability but reports from Europe and the United States indicated that the inline engine could offer greater performance. As a consequence, all development naval aircraft of the period were fitted with both types of engine to allow flying off trials. It was during such a test that the superiority of the radial engine for bombers established itself and the Navy ordered into production the Radial engined variant.

Variants

TB-31A-1
Initial prototype variant without dorsal turret and armament

TB-31A-2
Second and Third prototype variants with dorsal turret

TB-31A-3
Final prototype variant fitted with an inline engine for comparison tests

TB-31B-1
Initial production variant with twin gun dorsal turret and two forward firing machine guns in forward fuselage decking

TB-31B-2
Revised model with guns moved to wings and plumbing provided for carriage of external fuel tanks

TB-31C-1
Most produced variant with four wing-mounted guns and enlarged self-sealing fuel tanks

TB-31C-2
Modified TB-31C-1 with quad guns in dorsal turret

TB-31D-1
Proposed new model with a more powerful Movich MSh-2120 engine

DB-31A-1
Modified version developed into a Dive bomber, featured separately

Specifications (TB-31C-1)

General characteristics

Crew: 3
Length: 11.38 m (37 ft 4 in)
Wingspan: 13.11 m (43 ft)
Height: 4.27 m
Wing area: 32 m (= 342 ft)
Empty weight: 2,279 kg (5,024 lb)
Loaded weight: 3,800 kg (8,380 lb)
Max takeoff weight: 4,100kg (9,040 lb)
Powerplant: 1× Movich MSh-190 9-cylinder Radial engines, 671 kW (900 hp)

Performance

Maximum speed: 378 km/h (235 mph)
Combat radius: 1,255 km (780 mi)
Service ceiling: 8,000 m (26,247 ft)

Armament

2 × 7.7 mm (0.3 in) MG 37 machine guns in dorsal ball turret (drum fed, 97 rounds).
4 × 7.7 mm (0.3 in) MG 37 machine guns in wings (350 rpg)
1 x 1,786 lb (810 kg) Type N aerial torpedo or 1 x 1,760 lb (800 kg) bomb or 2 x 550 lb (250 kg) bombs

---

All of the above is taken from the wiki entry I've been working on of this aircraft; http://wikistates.outwardhosting.com/wiki/Korolev_TB-31

[eswube]

Might be interesting. Judging by that carriers size, it's going to be basically in the same category as UK's Colossus class. But to put there similar amount of aircraft (ca. 50 WW2-era) on a cruiser hull, You'd need to make a much deeper conversion than with Your previous carrier.

[denodon]

Yes my idea was to go for something along the lines of both the Colossus class and the USS Wasp (CV-7) for this. The hull itself here was not a conversion like the previous design but rather a purpose built one, the naval designers just kept the same basic hull structure as preparations had been made to manufacture the cruisers before they were cancelled due to costs and changing demands.

Also, being in the Bering Sea and North Pacific, I'm going to have to reduce the air group to whatever can fit into the hangar itself, however big it might be when I'm done with the design.

[eswube]

I'm not sure how much cruiser hulls (non-battlecruiser that is) are adaptable to being used for carriers (I'm thinking mostly about internal volume issues and the hull shape/width), but I think that air group of some 36 aircraft (3 squadrons, each of 12 fighters, dive bombers and torpedo bombers) with some space for several additional aircraft in case of emergency is entirely possible.

[denodon]

That airgroup is around the size I was thinking of yes, or perhaps reducing the size of the bomber wings to allow for additional fighter airframes on board. The hangar itself is internally subdivided (a result of having an armored flight deck requiring supports) so space within is as such handicapped. In any case, this carrier will most likely be operating within reach of the air forces aircraft (its just over 2,000nm from the capital Ulyanov to Tokyo I think I worked out once).

As for the cruiser hull, it is quite bulky in design (I ran a quick test in SS to see whether the speed might be feasible and for the desired displacement I had a beam of about 78 feet. The cruisers that were being designed were more for keeping trade route open in all-weather than as supporting fleet units (another reason why they were cancelled, Naval Hall wanted a design that could do both in the same hull, even if seakeeping had to be sacrificed).