WesWorld

Looking for comments on how to improve this. Carriers are not my forte and I've only just started looking at everyone else's take on CVs.

RAM indicated he wanted to lay down 2x 18,000 ton carriers in 1928- which is the quarters I'm supposed to be working on, so I need a carrier design to lay down , but I found no proposed designs. Earlier he had talked about 16,000 seeming the lower limit, I tried for a 15,000 "declared". As RAM had observed, if he could keep to the 15k range, Holland could fit an extra CV into her allocation.

Eendracht, Netherlands Carrier laid down 1928

Displacement:
14,862 t light; 15,268 t standard; 17,413 t normal; 19,129 t full load

Dimensions: Length overall / water x beam x draught
787.38 ft / 771.00 ft x 77.10 ft x 20.51 ft (normal load)
239.99 m / 235.00 m x 23.50 m x 6.25 m

Armament:
4 - 3.94" / 100 mm guns in single mounts, 30.51lbs / 13.84kg shells, 1928 Model
Dual purpose guns in deck mounts with hoists
on side, all amidships, all raised mounts - superfiring
8 - 3.94" / 100 mm guns in single mounts, 30.51lbs / 13.84kg shells, 1926 Model
Dual purpose guns in deck mounts with hoists
on side ends, evenly spread
24 - 1.57" / 40.0 mm guns (6x4 guns), 1.95lbs / 0.89kg shells, 1924 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
20 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1927 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 418 lbs / 190 kg
Shells per gun, main battery: 200

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 2.95" / 75 mm 442.91 ft / 135.00 m 13.12 ft / 4.00 m
Ends: Unarmoured
Main Belt covers 88 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.57" / 40 mm 0.98" / 25 mm 0.98" / 25 mm
2nd: 0.51" / 13 mm - -
3rd: 0.51" / 13 mm - -

- Armour deck: 1.97" / 50 mm, Conning tower: 1.57" / 40 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 95,879 shp / 71,525 Kw = 31.00 kts
Range 11,500nm at 15.00 kts
Bunker at max displacement = 3,861 tons

Complement:
757 - 985

Cost:
£3.749 million / $14.997 million

Distribution of weights at normal displacement:
Armament: 52 tons, 0.3 %
Armour: 2,219 tons, 12.7 %
- Belts: 728 tons, 4.2 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 26 tons, 0.1 %
- Armour Deck: 1,442 tons, 8.3 %
- Conning Tower: 23 tons, 0.1 %
Machinery: 2,985 tons, 17.1 %
Hull, fittings & equipment: 6,356 tons, 36.5 %
Fuel, ammunition & stores: 2,551 tons, 14.6 %
Miscellaneous weights: 3,250 tons, 18.7 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
29,760 lbs / 13,499 Kg = 975.4 x 3.9 " / 100 mm shells or 2.9 torpedoes
Stability (Unstable if below 1.00): 1.18
Metacentric height 4.6 ft / 1.4 m
Roll period: 15.1 seconds
Steadiness - As gun platform (Average = 50 %): 81 %
- Recoil effect (Restricted arc if above 1.00): 0.06
Seaboat quality (Average = 1.00): 1.62

Hull form characteristics:
Hull has raised forecastle
Block coefficient: 0.500
Length to Beam Ratio: 10.00 : 1
'Natural speed' for length: 27.77 kts
Power going to wave formation at top speed: 47 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 15.00 degrees
Stern overhang: 8.20 ft / 2.50 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 30.54 ft / 9.31 m
- Forecastle (20 %): 28.38 ft / 8.65 m (22.97 ft / 7.00 m aft of break)
- Mid (50 %): 22.97 ft / 7.00 m
- Quarterdeck (15 %): 22.97 ft / 7.00 m
- Stern: 22.97 ft / 7.00 m
- Average freeboard: 24.22 ft / 7.38 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 79.1 %
- Above water (accommodation/working, high = better): 228.9 %
Waterplane Area: 39,606 Square feet or 3,680 Square metres
Displacement factor (Displacement / loading): 147 %
Structure weight / hull surface area: 107 lbs/sq ft or 520 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.02
- Longitudinal: 1.04
- Overall: 1.02
Hull space for machinery, storage, compartmentation is excellent
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

LxB = 235m x 23.5m =5,522.5 / 70 =78.9
LxB = 771' x 77.1x59444 /750 =79.3
Misc : SQRT (3250) = 57 aircraft

Lower hanger has flying off deck and two catapults. Main flight deck has two catapults.
Two Elevators provided, one foreward of the last crash barrier, and one prior to the first crash barrier.

Weaponry is arranged with 4 single 100mm mounts fore/aft of the island, and the remaining 8 mounts in galleries below the flight deck, much like CV 6's 5" guns.

The flying off deck is for the same reason other navies tried it early on, it fits the developement stage and would theoretically boost scramble rate. The deck space far exceeds the air group size already.

I'd say she looks preaty good, allthough I wonder if the Dutch would be tempted to put a heavier main armament aboard.

I'd lower the freeboard a little bit, and replace the 4 100mm at deck level with 6"/15cm guns in shielded mounts. That's just because of the times, in the 1920s a carrier isn't necessarily going to be kept in the middle of the fleet, and the 100mms aren't going to dissuade much of anything larger than a torpedo boat from an attack on her.

I'd have said the same thing about lowering freeboard, except that he'll want the flying-off deck to high and dry. If the ship is wet forward, the deck will be useless.

I didn't think catapults were necessary at this point in history, even for flying-off decks.

The Dutch were in an AANM exercise that saw the Hund "sunk", apparently by surface forces. This might influence the final armament and speed.

There is a thread on the carrier designs RAM did propose - the search function should pull it up, I was just looking at it last week.

Well the biggest lack seems to be the guns.

Several options-
- use the 125mm DP of the newest DDs
- split battery with 152mm adjacent to the island, keeping the 100mm at the ends.
- adding aft casement guns much like Kaga.

I guess I'll have to look again for RAM's CVs, I may have skipped one of his pages when I was going back through his posts- say gone page 14, 12, etc. ?

Hund got "sunk" already? Darn I was going to take care of that !

RAM's thread is under "Future Dutch Carriers" on page 7 of the Ship Design area (ie, here where we are with this thread).

I wouldn't reduce the freeboard so much as to get the flying-off deck wet, I'd probably try to keep sea-keeping above 1.40 or so. But right now it's VERY high, so could stand some reduction.

Thanks Hrolf,

The sad thing is most of RAM's replies on that thread I have read already, but I had missed the carriers. Which means I missed reading one of the 21 pages that pop up when I search for RAM's 418 posts, and I don't know which one...

I see he was working with 12x125mm.

I can tinker with the freeboard, right now I think it's +2' over the default, as I was looking to keep my planes dry in all weather.

The other amusing thing is that your design here fits with his idea of building 4 x 15,000+ standard displacement ton ships and reporting them as 15,000 displacement ton ships. So you're pretty close already. Given his comments in that thread, though, you might want to go down a little in airgroup and up a little in protection, aim for an airgroup of 48 or so + some spares. Who knows, if the ships work out, Germany might be interested in an updated version of them in the mid-30s....

Sunk in the exercise, not physically sunk.

-The air group needs to be a bit over 48 to meet the needs based on some made up numbers I did

-yes, the 4x15 makes better sense given the expanse of sea routes than the 3x20

- I got the sunk in excercise , It's something I had planned on doing in the next Tri-annual.

-Freeboard, others need to chime in. When I dropped it the 1.08m to default, I lost (unusually) comp hull, so I'd rather not loose that 1.08m.

So here's a quick revamp. As RAM's 16k design had 30.5kts and 125mm guns, I changed to those.

================================
Eendracht, Netherlands Carrier laid down 1928

Displacement:
14,793 t light; 15,268 t standard; 17,413 t normal; 19,129 t full load

Dimensions: Length overall / water x beam x draught
787.50 ft / 771.00 ft x 77.10 ft x 20.51 ft (normal load)
240.03 m / 235.00 m x 23.50 m x 6.25 m

Armament:
8 - 4.92" / 125 mm guns (4x2 guns), 59.59lbs / 27.03kg shells, 1926 Model
Dual purpose guns in deck mounts with hoists
on side, all amidships, 2 raised mounts - superfiring
8 - 4.92" / 125 mm guns in single mounts, 59.52lbs / 27.00kg shells, 1926 Model
Dual purpose guns in deck mounts with hoists
on side ends, evenly spread
24 - 1.57" / 40.0 mm guns (6x4 guns), 1.95lbs / 0.88kg shells, 1924 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
20 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1927 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 1,004 lbs / 456 kg
Shells per gun, main battery: 200

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 2.95" / 75 mm 442.91 ft / 135.00 m 12.30 ft / 3.75 m
Ends: Unarmoured
Main Belt covers 88 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.18" / 30 mm 0.79" / 20 mm 0.79" / 20 mm
2nd: 1.18" / 30 mm 0.79" / 20 mm 0.79" / 20 mm
3rd: 0.51" / 13 mm - -
4th: 0.51" / 13 mm - -

- Armour deck: 1.97" / 50 mm, Conning tower: 1.57" / 40 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 90,083 shp / 67,202 Kw = 30.50 kts
Range 11,500nm at 15.00 kts
Bunker at max displacement = 3,861 tons

Complement:
757 - 985

Cost:
£3.879 million / $15.516 million

Distribution of weights at normal displacement:
Armament: 126 tons, 0.7 %
Armour: 2,207 tons, 12.7 %
- Belts: 683 tons, 3.9 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 59 tons, 0.3 %
- Armour Deck: 1,442 tons, 8.3 %
- Conning Tower: 23 tons, 0.1 %
Machinery: 2,805 tons, 16.1 %
Hull, fittings & equipment: 6,406 tons, 36.8 %
Fuel, ammunition & stores: 2,620 tons, 15.0 %
Miscellaneous weights: 3,250 tons, 18.7 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
29,580 lbs / 13,417 Kg = 496.4 x 4.9 " / 125 mm shells or 2.9 torpedoes
Stability (Unstable if below 1.00): 1.16
Metacentric height 4.5 ft / 1.4 m
Roll period: 15.3 seconds
Steadiness - As gun platform (Average = 50 %): 83 %
- Recoil effect (Restricted arc if above 1.00): 0.14
Seaboat quality (Average = 1.00): 1.67

Hull form characteristics:
Hull has raised forecastle
Block coefficient: 0.500
Length to Beam Ratio: 10.00 : 1
'Natural speed' for length: 27.77 kts
Power going to wave formation at top speed: 46 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 15.00 degrees
Stern overhang: 8.20 ft / 2.50 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 30.97 ft / 9.44 m
- Forecastle (20 %): 28.38 ft / 8.65 m (22.97 ft / 7.00 m aft of break)
- Mid (50 %): 22.97 ft / 7.00 m
- Quarterdeck (15 %): 22.97 ft / 7.00 m
- Stern: 22.97 ft / 7.00 m
- Average freeboard: 24.26 ft / 7.39 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 79.1 %
- Above water (accommodation/working, high = better): 228.9 %
Waterplane Area: 39,606 Square feet or 3,680 Square metres
Displacement factor (Displacement / loading): 144 %
Structure weight / hull surface area: 107 lbs/sq ft or 524 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.99
- Longitudinal: 1.04
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
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

LxB = 235m x 23.5m =5,522.5 / 70 =78.9
LxB = 771' x 77.1x59444 /750 =79.3
Misc : SQRT (3250) = 57 aircraft

Lower hanger has flying off deck and two catapults. Main flight deck has two catapults.
Two Elevators provided, one foreward of the last crash barrier, and one prior to the first crash barrier.

Weaponry is arranged with 4 single 100mm mounts fore/aft of the island, and the remaining 8 mounts in galleries below the flight deck, much like CV 6's 5" guns.

Quoted

Freeboard, others need to chime in. When I dropped it the 1.08m to default, I lost (unusually) comp hull, so I'd rather not loose that 1.08m.

Well, 1.08 meters is a lot. The others mentioned "a little bit".
I messed around a bit with the design and when lowering the freeboard aft of the forecastle by a mere 25 centimeters (6.75 meters instead of 7 meters), you'll have a situation where Cross-sectional strength is equal to Longitudinal strength. If you drop the freeboard by 1.08 meters (more than 4 times as much as I did in my test), Overall strength will definitely drop below 1.00. My guess would be about 0.97 or so.
If you were to lower that aft section by 0.25 meters, you will end up with an overall strength of 1.01. It's not much but it might be enough in case you want an 80 mm belt.

Quoted

Sunk in the exercise, not physically sunk.

Well, we can always change that, right?

One thing I noticed about the hull design is that, for it's length and beam, it seems quite shallow in draft. It might be worth trying to trade some length for a little more depth, at least see what it does to the design.

Gee, and I thought Rooijen's Japan was the friendly member of SATSUMA
Physically sink CV Hund indeed!

On the airgroup, 48 is indeed the minimum, I was projecting a "need" for 48 aircraft and 6 spares, so 54. The 57 gives a little room to grow.

I will play with draft and freeboard more.
edit: checking Ranger (730x80x19.75') and Wasp (688x80.75x20), with HMS Collosus (630x80x23) the draft may be ok as is for a vessel her size. Now 4' more beam might be recommended...

When "building" the hull there were a couple considerations
- General intent of a mix of Glorious and Enterprise
- I wanted about 100-150' for the flying off deck, and about 600-650+ for the main flight deck.

The length gave me a default stem height of 9.31m and a hull freeboard of 5.92m. I had a mental picture of this hapless biplane hurtling down the flying off deck towards a 10' high (well, 3.39m) wall. That seemed bad.

Dropping the stem would give me the wet forward remark and limit the intended value of the flying off deck. Simply ramping up would give me a 11% grade (if 100' flying off deck), and I wanted to bring that down a little.

So I brought the hull freeboard up, (which also fit with my desire to maximize the range of operating conditions)
and ramped the forecastle at ~8%. A small ramp fits what hazegray says about HMS Courageous's main flight deck.

Anyhow, thanks for the comments all, I will play with it a bit more this evening.

First, thanks for the comments earlier.

This is my second real effort at the same ship, focused on hull form. I expanded the beam slightly and cut some length. Draft remains 6.25m, as that appears comparable to OTL Wasp and Ranger as listed on Hazegray.

Since raising the freeboard from 5.92m to 7m was an issue on the first version, here's how I approached it :

Freeboard was raised 0.1m from default (5.76m to 5.86m), from stern "2" to "11", then the 1.6m ave 10% ramp of "12" to the bow, which is the default 9.06.

Now the tweaked ship :

Eendracht, Netherlands Carrier laid down 1928

Displacement:
14,604 t light; 15,075 t standard; 17,188 t normal; 18,879 t full load

Dimensions: Length overall / water x beam x draught
747.85 ft / 729.99 ft x 80.38 ft x 20.51 ft (normal load)
227.94 m / 222.50 m x 24.50 m x 6.25 m

Armament:
8 - 4.92" / 125 mm guns (4x2 guns), 59.52lbs / 27.00kg shells, 1926 Model
Dual purpose guns in deck mounts with hoists
on side, all amidships, all raised mounts - superfiring
8 - 4.92" / 125 mm guns in single mounts, 59.52lbs / 27.00kg shells, 1926 Model
Dual purpose guns in deck mounts with hoists
on side ends, evenly spread
24 - 1.57" / 40.0 mm guns (6x4 guns), 1.95lbs / 0.88kg shells, 1924 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
20 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1927 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 1,004 lbs / 455 kg
Shells per gun, main battery: 200

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 2.95" / 75 mm 393.70 ft / 120.00 m 11.48 ft / 3.50 m
Ends: Unarmoured
Main Belt covers 83 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.18" / 30 mm 0.79" / 20 mm 0.79" / 20 mm
2nd: 1.18" / 30 mm 0.79" / 20 mm 0.79" / 20 mm
3rd: 0.51" / 13 mm - -
4th: 0.51" / 13 mm - -

- Armour deck: 1.97" / 50 mm, Conning tower: 1.57" / 40 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 91,877 shp / 68,540 Kw = 30.50 kts
Range 11,500nm at 15.00 kts
Bunker at max displacement = 3,805 tons

Complement:
749 - 975

Cost:
£3.884 million / $15.535 million

Distribution of weights at normal displacement:
Armament: 126 tons, 0.7 %
Armour: 2,084 tons, 12.1 %
- Belts: 579 tons, 3.4 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 59 tons, 0.3 %
- Armour Deck: 1,424 tons, 8.3 %
- Conning Tower: 23 tons, 0.1 %
Machinery: 2,860 tons, 16.6 %
Hull, fittings & equipment: 6,398 tons, 37.2 %
Fuel, ammunition & stores: 2,584 tons, 15.0 %
Miscellaneous weights: 3,136 tons, 18.2 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
26,399 lbs / 11,975 Kg = 443.0 x 4.9 " / 125 mm shells or 2.8 torpedoes
Stability (Unstable if below 1.00): 1.21
Metacentric height 5.1 ft / 1.6 m
Roll period: 15.0 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.10
Seaboat quality (Average = 1.00): 1.31

Hull form characteristics:
Hull has raised forecastle
Block coefficient: 0.500
Length to Beam Ratio: 9.08 : 1
'Natural speed' for length: 27.02 kts
Power going to wave formation at top speed: 49 %
Trim (Max stability = 0, Max steadiness = 100): 54
Bow angle (Positive = bow angles forward): 18.00 degrees
Stern overhang: 8.20 ft / 2.50 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 29.72 ft / 9.06 m
- Forecastle (15 %): 24.48 ft / 7.46 m (19.23 ft / 5.86 m aft of break)
- Mid (50 %): 19.23 ft / 5.86 m
- Quarterdeck (15 %): 19.23 ft / 5.86 m
- Stern: 19.23 ft / 5.86 m
- Average freeboard: 20.33 ft / 6.20 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 80.4 %
- Above water (accommodation/working, high = better): 191.1 %
Waterplane Area: 39,095 Square feet or 3,632 Square metres
Displacement factor (Displacement / loading): 144 %
Structure weight / hull surface area: 116 lbs/sq ft or 566 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.09
- Longitudinal: 0.97
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

LxB = 222.5m x 24.5m =5,451.25 / 70 =77.9
LxB = 729.99'x 80.38 x58,676 /750 =78.2
Misc : SQRT (3136) = 56 aircraft

Vessel will be declared as 15,000 tons, but in truth is 0.5% over ! RAM said he wanted to cheat on the CVs, he'd be so pleased

Freeboard was raised 0.1m from default, from stern "2" to "11", then the 1.6m ave ramp of "12" to the bow, which is the default 9.06. Draft remains 6.25m, comparable to OTL Wasp and Ranger.

Lower hanger has 100' flying off deck forward ramped at 10% and two catapults.
Primary use is meant to be unassisted fighter launch.
Main flight deck is 630' long. Two elevators are provided, one forward of the last crash barrier, and one prior to the first crash barrier.

Weaponry is arranged with 4 twin 125mm mounts fore/aft of the island, and the remaining 8 single mounts in galleries below the flight deck fore and aft, much like CV 6's 5" guns.

Quoted

Gee, and I thought Rooijen's Japan was the friendly member of SATSUMA

Friendly? Me? O_O
... guess I am doing something wrong then! :-)

Quoted

Originally posted by Rooijen10

Quoted

Gee, and I thought Rooijen's Japan was the friendly member of SATSUMA

Friendly? Me? O_O
... guess I am doing something wrong then! :-)

OOC : No you're doing great! The mild conciliatory bit after the ranting rhetoric of the SATSUMA announcements, combined with the mention of the 300 years of peaceful trade... I'm completely convinced Japan will invade India on behalf of the Netherlands. !

Anyhow, since there's no further comments, I'll post the CV in the Netherlands fleet and post Q3-4/1928.
I did make one change- I noted it was 2.5m to long for the next lowest slip and so lopped 2.5m off the bow and increased the bc by 0.01. That did the trick.

Thanks all.

-Kaiser Kirk
(edit- darn my sfelling errors! err spelling...)

Quoted

No you're doing great! The mild conciliatory bit after the ranting rhetoric of the SATSUMA announcements, combined with the mention of the 300 years of peaceful trade... I'm completely convinced Japan will invade India on behalf of the Netherlands. !

True the past is important, but the present is even more important. :-)

Quoted

I did make one change- I noted it was 2.5m to long for the next lowest slip and so lopped 2.5m off the bow and increased the bc by 0.01. That did the trick.

I noticed that, but didn't mention it since I thought there was probably some evil plan involved with the decision to use a bigger slip for the carrier.