Design Bureau Guangzhou

[The Rock Doctor]

Setting aside concerns about the carrier's overall size - you've not allowed adequate height for the hangers.  You're going to need something like 14-16 feet to stow a torpedo-bomber.  You've only got ten feet now.

Also, the freeboard break implies that the upper hanger only covers the forward 50% of the ship, which would have implications for total aircraft stowage.

[Logi]

??? The thread says that is how you simulate a hurricane bow.

Also noted for the height of the torpedo-bomber, I mistakenly assumed ten feet would be enough.

EDIT: Also, the BC of 0.457 is basically a copy of the BC on the USS Ranger.

[Sachmle]

??? The thread says that is how you simulate a hurricane bow.

Why would you want to do that? They didn't get used IRL until 1927. We have NO experience w/ CVs to indicate that a hurricane bow, which adds topweight and overall weight, does anything for performance yet.

[Logi]

We don't see the point of having a gaping hole in the front where seawater might wash in.

Not to mention we already have more than enough AA on the ship already, so that open space really isn't needed.

[The Rock Doctor]

The 15% forecastle would be your hurricane bow, then (as currently simmed) 35% for the upper hanger, then a hull break to the roof of the lower hanger.  At least, that's how I interpret it.

[Logi]

There, now a flying-off-deck carrier.

Maximum space would be ~46 planes, at 70% capacity, the ship can carry 32 planes, thereby negating the need for a second hangar.

AA armament is reduced to 8 40mm Pom-poms per side (two quads).

Anti-ship armament is boosted to 8 105mm guns per side. The weapons will greatly aid in stopping destroyers attacks on the taskforce.

It is about twice the size of the original seaplane tender (which was designed to fit in a type 1 Dock, this one fits in a type 2 dock).

The B/C used is that of Yorktown.

Deck is armored (3") to make sure the flight deck is operational and will not break down (and thus be in need for are repairs of a long time) if hit by a stray shell.

Yichang, RRC Carrier Escort laid down 1920 (Engine 1916)

Displacement:
   8,000 t light; 8,249 t standard; 9,023 t normal; 9,642 t full load

Dimensions: Length overall / water x beam x draught
   557.74 ft / 557.74 ft x 63.00 ft x 17.00 ft (normal load)
   170.00 m / 170.00 m x 19.20 m  x 5.18 m

Armament:
      16 - 4.13" / 105 mm guns (8x2 guns), 35.32lbs / 16.02kg shells, 1920 Model
     Quick firing guns in deck mounts with hoists
     on side, evenly spread
      16 - 1.60" / 40.6 mm guns (4x4 guns), 2.05lbs / 0.93kg shells, 1920 Model
     Anti-aircraft guns in deck mounts with hoists
     on side, evenly spread
   Weight of broadside 598 lbs / 271 kg
   Shells per gun, main battery: 200

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.50" / 13 mm         -               -
   2nd:   0.50" / 13 mm         -               -

   - Armour deck: 4.00" / 102 mm, Conning tower: 4.00" / 102 mm

One Lightweight Hangar

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 36,790 shp / 27,445 Kw = 26.00 kts
   Range 8,000nm at 12.00 kts
   Bunker at max displacement = 1,392 tons

Complement:
   462 - 601

Cost:
   £1.264 million / $5.055 million

Distribution of weights at normal displacement:
   Armament: 75 tons, 0.8 %
   Armour: 1,833 tons, 20.3 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 17 tons, 0.2 %
      - Armour Deck: 1,779 tons, 19.7 %
      - Conning Tower: 37 tons, 0.4 %
   Machinery: 1,371 tons, 15.2 %
   Hull, fittings & equipment: 3,446 tons, 38.2 %
   Fuel, ammunition & stores: 1,023 tons, 11.3 %
   Miscellaneous weights: 1,276 tons, 14.1 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     12,215 lbs / 5,541 Kg = 345.8 x 4.1 " / 105 mm shells or 2.2 torpedoes
   Stability (Unstable if below 1.00): 1.14
   Metacentric height 3.2 ft / 1.0 m
   Roll period: 14.8 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.08
   Seaboat quality  (Average = 1.00): 1.03

Hull form characteristics:
   Hull has raised forecastle
   Block coefficient: 0.529
   Length to Beam Ratio: 8.85 : 1
   'Natural speed' for length: 23.62 kts
   Power going to wave formation at top speed: 48 %
   Trim (Max stability = 0, Max steadiness = 100): 68
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      21.00 ft / 6.40 m
      - Forecastle (15 %):   21.00 ft / 6.40 m (11.00 ft / 3.35 m aft of break)
      - Mid (50 %):      11.00 ft / 3.35 m
      - Quarterdeck (15 %):   11.00 ft / 3.35 m
      - Stern:      11.00 ft / 3.35 m
      - Average freeboard:   12.50 ft / 3.81 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 72.1 %
      - Above water (accommodation/working, high = better): 109.0 %
   Waterplane Area: 24,039 Square feet or 2,233 Square metres
   Displacement factor (Displacement / loading): 140 %
   Structure weight / hull surface area: 106 lbs/sq ft or 519 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 1.37
      - Longitudinal: 0.90
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is adequate
   Ship has slow, easy roll, a good, steady gun platform

Hurricane Bow

Misc Weight (1276 tons)
1024 tons - 32 Aircrafts (4 scouts, 28 torpedo-bombers)
100 tons - Fire Control System/Director (for Anti-Ship/AAW operation)
25 tons - Long Range Wireless
25 tons - Radar
102 tons - 102 21" tons

[Sachmle]

We don't see the point of having a gaping hole in the front where seawater might wash in.

Not to mention we already have more than enough AA on the ship already, so that open space really isn't needed.

Fair enough, but no one else ever thought the 'gaping hole' was an issue until one got stuck in a hurricane. Remember, even with your previous success on land w/ planes, and the recent 'success' at sea, most rational people are still going to see them as toys, and wasting valuable tonnage on a special ship just for toys is probably not going to be a 'popular' idea in a lot of circles (black shoes anyone?). So making them as cost effective as possible is the best way to win support until they're proven, unequivocally to be effective. That's why almost all 1st try carriers/sea plane tenders were converted merchant ships with minimum of structure added. That's why they had the open bow. Just supports and a wooden deck forward usually.

[Logi]

Actually I knew such would be unpopular that's why I attempted it as small as possible, the 4000 tons Yichang being the result of that.

I would have used a converted merchant ship but the problem is as follows: Merchants ships are not capable of speeds of 26 kts. That is requires for operating with the task force.

However perhaps we can built the ship to mercantile standard (rather than convert it). That would be nice and cheap.

[Logi]

Merchant Standard Version, the extra weight had to go somewhere so it went to increasing the number of planes carried.

It now carries the full 46 planes possible and has two hangars.

Yichang, RRC Carrier Escort laid down 1920 (Engine 1916)

Displacement:
   8,000 t light; 8,266 t standard; 9,842 t normal; 11,103 t full load

Dimensions: Length overall / water x beam x draught
   557.74 ft / 557.74 ft x 63.00 ft x 18.00 ft (normal load)
   170.00 m / 170.00 m x 19.20 m  x 5.49 m

Armament:
      16 - 4.13" / 105 mm guns (8x2 guns), 35.32lbs / 16.02kg shells, 1920 Model
     Quick firing guns in deck mounts with hoists
     on side, evenly spread
      16 - 1.60" / 40.6 mm guns (4x4 guns), 2.05lbs / 0.93kg shells, 1920 Model
     Anti-aircraft guns in deck mounts with hoists
     on side, evenly spread
   Weight of broadside 598 lbs / 271 kg
   Shells per gun, main battery: 200

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.50" / 13 mm         -               -
   2nd:   0.50" / 13 mm         -               -

   - Conning tower: 3.70" / 94 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 38,959 shp / 29,064 Kw = 26.00 kts
   Range 16,000nm at 12.00 kts
   Bunker at max displacement = 2,837 tons

Complement:
   493 - 642

Cost:
   £1.291 million / $5.162 million

Distribution of weights at normal displacement:
   Armament: 75 tons, 0.8 %
   Armour: 53 tons, 0.5 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 17 tons, 0.2 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 37 tons, 0.4 %
   Machinery: 1,452 tons, 14.7 %
   Hull, fittings & equipment: 3,986 tons, 40.5 %
   Fuel, ammunition & stores: 1,842 tons, 18.7 %
   Miscellaneous weights: 2,434 tons, 24.7 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     18,378 lbs / 8,336 Kg = 520.3 x 4.1 " / 105 mm shells or 2.1 torpedoes
   Stability (Unstable if below 1.00): 1.10
   Metacentric height 3.0 ft / 0.9 m
   Roll period: 15.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 66 %
         - Recoil effect (Restricted arc if above 1.00): 0.19
   Seaboat quality  (Average = 1.00): 2.00

Hull form characteristics:
   Hull has raised forecastle
   Block coefficient: 0.545
   Length to Beam Ratio: 8.85 : 1
   'Natural speed' for length: 23.62 kts
   Power going to wave formation at top speed: 49 %
   Trim (Max stability = 0, Max steadiness = 100): 33
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      43.00 ft / 13.11 m
      - Forecastle (15 %):   43.00 ft / 13.11 m (27.00 ft / 8.23 m aft of break)
      - Mid (50 %):      27.00 ft / 8.23 m
      - Quarterdeck (15 %):   27.00 ft / 8.23 m
      - Stern:      27.00 ft / 8.23 m
      - Average freeboard:   29.40 ft / 8.96 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 81.4 %
      - Above water (accommodation/working, high = better): 254.5 %
   Waterplane Area: 24,399 Square feet or 2,267 Square metres
   Displacement factor (Displacement / loading): 164 %
   Structure weight / hull surface area: 84 lbs/sq ft or 409 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.86
      - Longitudinal: 3.82
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is excellent
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Two Lightweight Hangars
Hurricane Bow

Misc Weight (2434 tons)
2116 tons - 46 Aircraft
100 tons - Fire Control System/Director (for directing Anti-ship and AAW)
25 tons - Long Range Wireless
25 tons - Radar
168 tons - 168 Aerial 21" Torpedoes

[damocles]

Analysis: not possible in 1920.

Reason:

USS Langley

General characteristics
Displacement:    19,360 long tons (19,670 t) (as Jupiter)
11,500 long tons (11,700 t) (as Langley)
13,000 tons (normal as Langley)
Length:    542.3 ft (165.3 m)
Beam:    65.3 ft (19.9 m)
Draft:    27 ft 8 in (8.43 m) (as Jupiter)
18 ft 11 in (5.77 m) (as Langley)
Installed power:    6,500 shp (4,800 kW)
Propulsion:    General Electric turbo-electric drive
3 × boilers
2 × shafts
Speed:    15.5 kn (17.8 mph; 28.7 km/h)
Complement:    163 officers and men (as Jupiter)
468 officers and men (as Langley)
Armament:    4 × 4 in (100 mm)/50 cal guns (as Jupiter)
4 × 5 in (130 mm)/51 cal guns (as Langley)
Armor:    None
Aircraft carried:    None (as Jupiter)
34 (as Langley)

HIJMS Ryujo.

Class and type:    Ry?j? class light aircraft carrier
Displacement:    10,600 tons (standard)
13,650 tons (loaded)
Length:    179.9 m (590.3 ft)
Beam:    20.8 m (68.2 ft)
Draught:    7.1 m (23.3 ft)
Propulsion:    Steam turbines,
6 boilers, 2 shafts,
48.5 MW (65,000 hp)
Speed:    54 km/h (29 knots)
Range:    19,000 km at 26 km/h
  (10,000 nmi at 14 kts)
Complement:    924
Armament:    8 × 127 mm (5 in) guns,
4 × 25 mm anti-aircraft guns,
24 × 13 mm machine guns
Aircraft carried:    48 (operational maximum 37)

My own test carrier was modeled blind on a Ryujo type design.

40 planes on < 10,000 tons is ridiculous especially with that many heavy guns. I wouldn't even consider 35 possible.

[Logi]

Analysis, you need to read the previous posts.

The USS Langley was a conversion, conversations are very inefficient and thus carry less planes.

EDIT: Actually Langely fits into the given rule set as conversions need 1.5 times the mic weight to carry the same amount of aircraft as a true aircraft carrier. That means it carries 66% of the planes it would if it was build as a aircraft carrier in the first place.

As a result, if the Langley were not a conversion it would be able to carry 51 planes.

Also Ryujo goes at 29 knots, that's a lot more machinery space and weight that the Yichang does not need.

[damocles]

Analysis, you need to read the previous posts.

The USS Langley was a conversion, conversations are very inefficient and thus carry less planes.

I did and noted the comments you made as invalid as your own "merchant conversion of 40 planes" was technically not possible. As for Ryujo, it was not a conversion.  So two benchmarks for the two test cases.   

Your 8000 ton light carriers cannot have 40 planes. We have to make some kind of sense here, don't we?

D.

[Logi]

The Ryujo also goes at 29 knots.

If the Yichang were to go at 29 knots, that would result in 784 tons more machinery weight. Most certainly at 29 knots, a Yichang-sized aircraft carrier can not hope to carry such a large hangar. But it goes at a slow 26kts speed.

You would also note that my Yichang has the same number of mounts for it's weapon as tyhe Ryujo and far fewer AA weapon mounts.

I have 8 mounts of 105mm guns (which are not 5" guns) and they are dual. That is why I can fit them on.

I have 4 mounts of 40mm quads, compared to Ryujo's 28 mounts.

Do I even need to metnion that under that rule set, the Ryujo requires 188 tons more for it's aircraft complement and not even counting the additional reloads need?

That means a total of 972 tons of just machinery and aircraft that the Ryujo carries over the Yichang.

Also I should note that the Ryujo, as designed, displaced only 8,000 tons as well. The inability of the Ryujo to weather heavy storms required the addition of weight. The instabilty of the ship was caused by the addtional of a second hangar into the ship halfway through construction, a detail that was not included in the original build plan for the Ryujo, which prompted it's instability.

This instability requires more weight to offset.

Hence, a purpose-designed ship with two hangars from the start would not encounter stability issues as heavily as the Ryujo and there is no need to add the additional 2k tons.

EDIT: I never said Merchant Conversion. I said built to Merchant Standard. Those are two entirely different things.

One is a conversion which leads to inefficiency in hull form and design.

The other is a perfectly well designed ship with cheap materials.

[Desertfox]

Hosho might be a better comparison choice...

[Carthaginian]

I don't know if 26 knots is exactly 'merchant standard.'
Surely a carrier like this would fall more under the 'Tender Rule Clause' intended to prevent 'cheap warships.'

Seriously, the Mods need to rule on this issue before someone starts laying down the keel on a 20,000t fleet carrier built to MS.