WesWorld

An idea I'm toying with for the Dutch- this is no more than a draft. Interested in both conceptual and technical comments.




With good radar, prox fuses and soon RPC, and no substantial Air-sea combat to test them, the Dutch are feeling pretty good about the ability of a coherent squadron to beat off at least some air attack.

However, some air cover to intercept & disrupt incoming attacks is a large plus, and the ability to intercept and destroy maritime recon flights is desirable.

Combine that with the old belief that between detection and attack, you can only launch so many fighters. Radar has extended detection, but flight speeds are up. Having 100 fighters is worthless if you can only fuel/arm/start/launch/intercept with 24 due to time. CAP is an extremely expensive drain on fuel, men & machines and so reserved for high threat times.

So...if the purpose is to launch a limited number of fighters, what would a carrier to fit that role look like?


Possibly too slow as she can't accompany the light cruiser divisions at top speed, but that might be an acceptable sacrifice. She can manage to back up the battleships, heavy cruisers, carriers and could be put on convoys or scout for a raiding squadron if needed.

Draft , Netherlands Fighter Carrier laid down 1943

Displacement:
9,497 t light; 9,960 t standard; 11,084 t normal; 11,983 t full load

Dimensions: Length overall / water x beam x draught
583.93 ft / 557.74 ft x 68.90 ft x 16.73 ft (normal load)
177.98 m / 170.00 m x 21.00 m x 5.10 m

Armament:
8 - 3.54" / 90.0 mm guns in single mounts, 22.05lbs / 10.00kg shells, 1943 Model
Dual purpose guns in deck mounts with hoists
on side ends, evenly spread
4 - 3.54" / 90.0 mm guns (2x2 guns), 22.05lbs / 10.00kg shells, 1943 Model
Dual purpose guns in deck mounts with hoists
on side, all amidships, all raised mounts - superfiring
8 - 1.57" / 40.0 mm guns in single mounts, 1.98lbs / 0.90kg shells, 1943 Model
Anti-aircraft guns in deck mounts with hoists
on side, evenly spread, all raised mounts
32 - 1.57" / 40.0 mm guns (16x2 guns), 1.98lbs / 0.90kg shells, 1943 Model
Anti-aircraft guns in deck mounts with hoists
on side, evenly spread
16 - 0.91" / 23.0 mm guns (1x16 guns), 0.44lbs / 0.20kg shells, 1943 Model
Anti-aircraft guns in deck mount
on side
Weight of broadside 351 lbs / 159 kg
Shells per gun, main battery: 1,000

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 2.95" / 75 mm 387.14 ft / 118.00 m 9.97 ft / 3.04 m
Ends: Unarmoured
Main Belt covers 107 % of normal length

- Torpedo Bulkhead:
0.98" / 25 mm 387.14 ft / 118.00 m 15.78 ft / 4.81 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.97" / 50 mm 2.95" / 75 mm 1.97" / 50 mm
2nd: 1.97" / 50 mm 2.95" / 75 mm 1.97" / 50 mm
3rd: 0.39" / 10 mm 1.77" / 45 mm 0.20" / 5 mm
4th: 0.39" / 10 mm 1.77" / 45 mm 0.20" / 5 mm
5th: 0.39" / 10 mm - -

- Armour deck: 1.97" / 50 mm, Conning tower: 0.98" / 25 mm

Machinery:
Oil fired boilers, steam turbines,
Electric motors, 4 shafts, 76,263 shp / 56,892 Kw = 31.00 kts
Range 9,500nm at 15.00 kts
Bunker at max displacement = 2,023 tons

Complement:
539 - 702

Cost:
£4.222 million / $16.887 million

Distribution of weights at normal displacement:
Armament: 44 tons, 0.4 %
Armour: 1,919 tons, 17.3 %
- Belts: 481 tons, 4.3 %
- Torpedo bulkhead: 222 tons, 2.0 %
- Armament: 135 tons, 1.2 %
- Armour Deck: 1,070 tons, 9.7 %
- Conning Tower: 11 tons, 0.1 %
Machinery: 1,970 tons, 17.8 %
Hull, fittings & equipment: 4,415 tons, 39.8 %
Fuel, ammunition & stores: 1,587 tons, 14.3 %
Miscellaneous weights: 1,150 tons, 10.4 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
24,787 lbs / 11,243 Kg = 1,114.4 x 3.5 " / 90 mm shells or 3.5 torpedoes
Stability (Unstable if below 1.00): 1.15
Metacentric height 3.7 ft / 1.1 m
Roll period: 15.0 seconds
Steadiness - As gun platform (Average = 50 %): 76 %
- Recoil effect (Restricted arc if above 1.00): 0.10
Seaboat quality (Average = 1.00): 1.50

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.603
Length to Beam Ratio: 8.10 : 1
'Natural speed' for length: 27.10 kts
Power going to wave formation at top speed: 61 %
Trim (Max stability = 0, Max steadiness = 100): 51
Bow angle (Positive = bow angles forward): 25.00 degrees
Stern overhang: 13.12 ft / 4.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 28.02 ft / 8.54 m
- Forecastle (20 %): 28.02 ft / 8.54 m
- Mid (50 %): 28.02 ft / 8.54 m
- Quarterdeck (15 %): 28.02 ft / 8.54 m
- Stern: 28.02 ft / 8.54 m
- Average freeboard: 28.02 ft / 8.54 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 105.5 %
- Above water (accommodation/working, high = better): 291.0 %
Waterplane Area: 29,386 Square feet or 2,730 Square metres
Displacement factor (Displacement / loading): 151 %
Structure weight / hull surface area: 93 lbs/sq ft or 453 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.90
- Longitudinal: 2.71
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

Warning: Raised guns + low guns > total guns - 3rd battery


This vessel is intended to provide fighter cover for various fleet efforts.

With the foreseen wingloading of the Dutch carrier fighters, it is expected they may fly off the decks unassisted, as may the T-VI torpedo-scout biplane. Provision is made for some autogyros or helicopters with the expectation they may serve a use for ship-shore communications, Air/Sea rescue, ASW and aerial reconn.

Twin catapults allow for heavier aircraft to be carried, but sortie rate will be low.

The ship is intended to carry a limited number of helicopters/autogyros.

The ship's structure ends at 5.04m above WL, and a 3.5m high hanger crowns that.

Most of the Anti-aircraft suite is arranged at deck edge, but twin 90mm are fore/aft of the island, and superimposed 40mm tubs also sit there.

Magazine size is doubled from 500rpg to 1000rpg to allow for an additional 120 tons aircraft munitions.
Likewise the last 1000nm of fuel is 133tons of AVGAS tanks.

Misc weight is arranged as follows
900 tons : Aircraft - 18 fighters, 6 reconn/torpedo planes, 6 autogyros / helicopters. (LxB)/70 = 51
200 tons : Electronics and "stuff"
50 tons : Extra

Perhaps not a novel idea, Italy had the converted cruisers Alberico da Barbiano and Bartolomeo Colloeoni which served as fighter carriers until they were sold to Siam in 1940.

I've toyed with the idea myself a few times and it makes sense to provide a pure fighter carrier to leave the bigger fleet carriers free to carry the strike wings with their heavier aircraft and larger payloads. Catapults are a useful addition for future growth, or for use when mass launches aren't neccessary or when conditions aren't favourable for unassisted take-off. Certainly by not using the catapults you'll save on airframe fatigue too.

IMO the light AA armament seems a excessive for a carrier this size, 40x 40mm in a majority of twin mounts is going to congest the flight deck sides. I know its a draft but a single 16x 23mm mount is going to be impressive! I assume these will also be twins? That's at least four 90mm, eleven 40mm mounts and eight 23mm mounts on each side of the ship (of course excluding the twin 90mm and two twin 40mm around the island).

Armour looks ok, not too heavy but good enough to absorb some damage, speed and range seem ok as well. With good radar and a decent CIC and Interception Control I'd expect either a sizable island or, more likely, a big internal command space within the hull. Growth is going to be a big factor though, future fighters will on only grow in weight and size, with a theoretical space for 24 aircraft that's not bad but beyond 1945 that airgroup will shrink. Once you get to a 12-fighter sqaudron strength then the practicality of the concept declines.

It's an interesting concept though, and one that might have its uses in the Far East.

Grengam was laid down in 1940 to provide scouting and CAP for non-CV-centered task forces. Russia has 5 carriers with normal displacement around 16,000 tons. Strike aircraft are fast exceeding a size that will fit comfortably on them, so RF naval staff will have the refitted as they need it to serve the CAP/scouting role for both battle groups and carrier groups.

The Azov class and its follow-on classes are big enough to handle strike aircraft and their long-range escorting fighters.

And even jets!

I don't think a carrier this small is going to age well.

The hanger doesn't seem very high at all - I recall reading that the Implacables were historically junked because their ~4.2 metre hangers weren't high enough in the late '40s.

Quoted

Originally posted by The Rock Doctor
I don't think a carrier this small is going to age well.

The hanger doesn't seem very high at all - I recall reading that the Implacables were historically junked because their ~4.2 metre hangers weren't high enough in the late '40s.

Yeah, I did some digging in HMS Illustrious after I posted, and the 3.5m hangers are too short, limiting which planes can be there. It's still fighter-centric, so smaller overall, and 4.5m hanger works at 10,000tons.

Of course some folks don't bother modeling a hanger, ascribing it to the 'misc weight' set aside, but I've come round to 'paying' for that part of the structure.

And it may be it doesn't age well. That's a useful critique. I tried to make it chunky to provide a decent hanger space, and 30 planes in a 51 space hanger is 3/5 - par for good ops.

But early jets did have lousy take off rolls.

I'll have to look at some pics to see if the AA is excessive.

Hmm they are closer to the USS Independence class than I realized.

To chime in with Hood and AdmK, the Canadians have operated Hermes in this capacity during several Fleet Problems over the years, as well. That's been her envisioned role with the RCN in wartime ever since I aquired the Weird Sisters.

I agree that her AA suit is too large. Make a sketch and I doubt you will find enough space - then count in top weight and crew numbers plus the need to support all those guns with ammo and you will see it will not work.

I'd also try a hull a tad bit longer and less beamy. But that's probably just me.

Hull: Longer may be necessary to unsure viability in the longer run- as Rocky critiqued. Here the idea was something that could be built and repaired in the more common type 3 docks.



I’m willing to “sacrifice” the long term capability to operate jet attack aircraft, but SAE and the Netherlands are exploring (in our oh-so-copious writing) jet fighters, so those basic parameters should be part of the Dutch consideration.

I think jet fighters with CAT assist could launch….but could they land? I haven’t a clue. Wingloading would be part of it. I suppose I could scale out the arrestor gear section of the USS United States to get an idea of the space requirements.

Beam however is controlled by a couple factors- the desire to have sufficient aircraft working space, and the desire to have a functioning TDS, thus a 15m Cruiser sized hull + ~3m each side = 21m, I don’t really want to go less. Likewise the boxy BC is deliberate, as I want a wider hanger for as much space as possible.

Armament.
Normally I don’t do scale drawings. Tried some in the past, took forever, and really not my talent.

Generally the way I double check is to look at the deck plans for a similar vessel, and ask if what I envision looks like it fits. Here, I think the objections- at least for the 90mm & 40mm- may be correct, the 23mm really don't take up much space though- look at how packed the gun galleries on a BB were- a 23mm every 10ft or so.



So, here's "the next step up".... a bit longer, a fair bit greater in displacement. Runs about 40 AC easily. I stepped the AA down, though with the greater length it may now work. Something like a Colossus class now, less a Bouge. Problem is, she's already starting to get kinda pricey, though at 720ft OA, probably more utility than 584ft OA, and more useful in the jet age... and I suppose that in 1943 jets were just about to be used. The 170m carrier might be too late, may have been more reasonable in 1938.

Draft , Netherlands Fighter Carrier laid down 1943

Displacement:
12,748 t light; 13,255 t standard; 14,686 t normal; 15,831 t full load

Dimensions: Length overall / water x beam x draught
720.83 ft / 688.98 ft x 68.90 ft x 18.86 ft (normal load)
219.71 m / 210.00 m x 21.00 m x 5.75 m

Armament:
8 - 3.54" / 90.0 mm guns (4x2 guns), 22.05lbs / 10.00kg shells, 1943 Model
Dual purpose guns in deck mounts with hoists
on side ends, evenly spread
8 - 1.57" / 40.0 mm guns (2x4 guns), 1.98lbs / 0.90kg shells, 1943 Model
Anti-aircraft guns in deck mounts with hoists
on side, evenly spread, all raised mounts
24 - 1.57" / 40.0 mm guns (6x4 guns), 1.98lbs / 0.90kg shells, 1943 Model
Anti-aircraft guns in deck mounts with hoists
on side, evenly spread
16 - 0.91" / 23.0 mm guns in single mounts, 0.44lbs / 0.20kg shells, 1943 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 247 lbs / 112 kg
Shells per gun, main battery: 1,300

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 2.95" / 75 mm 447.83 ft / 136.50 m 9.97 ft / 3.04 m
Ends: Unarmoured
Main Belt covers 100 % of normal length
Main belt does not fully cover magazines and engineering spaces

- Torpedo Bulkhead:
0.98" / 25 mm 447.83 ft / 136.50 m 17.55 ft / 5.35 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.97" / 50 mm 2.95" / 75 mm 1.97" / 50 mm
3rd: 0.39" / 10 mm 1.77" / 45 mm 0.20" / 5 mm
4th: 0.39" / 10 mm 1.77" / 45 mm 0.20" / 5 mm
5th: 0.39" / 10 mm - -

- Armour deck: 1.57" / 40 mm, Conning tower: 0.98" / 25 mm

Machinery:
Oil fired boilers, steam turbines,
Electric motors, 4 shafts, 92,550 shp / 69,042 Kw = 32.00 kts
Range 10,100nm at 15.00 kts
Bunker at max displacement = 2,576 tons

Complement:
666 - 867

Cost:
£5.280 million / $21.121 million

Distribution of weights at normal displacement:
Armament: 31 tons, 0.2 %
Armour: 1,956 tons, 13.3 %
- Belts: 551 tons, 3.7 %
- Torpedo bulkhead: 286 tons, 1.9 %
- Armament: 78 tons, 0.5 %
- Armour Deck: 1,028 tons, 7.0 %
- Conning Tower: 13 tons, 0.1 %
Machinery: 2,390 tons, 16.3 %
Hull, fittings & equipment: 6,342 tons, 43.2 %
Fuel, ammunition & stores: 1,938 tons, 13.2 %
Miscellaneous weights: 2,030 tons, 13.8 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
35,104 lbs / 15,923 Kg = 1,578.2 x 3.5 " / 90 mm shells or 4.3 torpedoes
Stability (Unstable if below 1.00): 1.11
Metacentric height 3.5 ft / 1.1 m
Roll period: 15.5 seconds
Steadiness - As gun platform (Average = 50 %): 80 %
- Recoil effect (Restricted arc if above 1.00): 0.08
Seaboat quality (Average = 1.00): 2.00

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.574
Length to Beam Ratio: 10.00 : 1
'Natural speed' for length: 29.72 kts
Power going to wave formation at top speed: 54 %
Trim (Max stability = 0, Max steadiness = 100): 40
Bow angle (Positive = bow angles forward): 25.00 degrees
Stern overhang: 16.40 ft / 5.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 33.14 ft / 10.10 m
- Forecastle (20 %): 33.14 ft / 10.10 m
- Mid (50 %): 33.14 ft / 10.10 m
- Quarterdeck (15 %): 33.14 ft / 10.10 m
- Stern: 33.14 ft / 10.10 m
- Average freeboard: 33.14 ft / 10.10 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 101.1 %
- Above water (accommodation/working, high = better): 334.5 %
Waterplane Area: 35,293 Square feet or 3,279 Square metres
Displacement factor (Displacement / loading): 163 %
Structure weight / hull surface area: 94 lbs/sq ft or 461 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.87
- Longitudinal: 3.38
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

The second design surely is more useful - simply because of her size. THe reduction od guns and the more lengthy deck is what I noted first. Less guns means less topweght and less crews or ammo lying around while a longer deck buys you deck space for a/c operations, probably deck parking and obviously more runway area.

If the Dutch can afford it, I recommend the second design.

I compared your first design with the RSAN CVL Michael Endress and you second to CVL Anvil. Size is almost identical but there is at least a decade of design experience between them and the Dutch design philosophy is different. Your second design has more guns, more armor and more speed than the Anvil, but has no double storey hangar and only 2/3 of the Anvils aircraft complement. Given the advance of the jet age your design is prepared for, the latter probably is not really a problem.

I think the extra cost is well worth it. The additional space should allow for a longer service life.

Note that the belt length may need a touch-up.

Looks better. I wouldn't go too crazy about "the jet age" but even piston fighters are going to grow, even something like a Sea Fury is bigger than the early 30s types.
I wonder whether it might save a bit of weight to just armour the magazines and do away with a traditional belt?
The AA armament looks much better now too.