Random thoughts on future techs

[Kaiser Kirk]

Information
Current "aviation ship design"

Conversions
Conversions are inherently inefficient. Multiply required weights by 1.5.

That was based on the oddly small airgroups of the BB/BC conversions.

Going forward, should be changed to 'weights and space'


Comment / Explanation :
One great concern to me is that carriers & in particular their air groups are underpriced in Navalism.

I feel that we look at WW2 and the host of small carriers the RN and USN had, and feel we should have some of the same.  However, this neglects these were a wartime contingency the two largest economic powers in the world, larger and richer than any N7 PC.

That is why I was proposing the brand new 'mercantile construction carrier'
to meet these historical categories, which would be cheaper but not cheap.
I freely admit it violates Snip's KISS, so folks may not wish to explore that route. 

[Jefgte]

...We'd build the original hulls of a Langley or an Argus as mercantile hulls (1/4 cost) and get a warship out of it - that would be the problem.

1/4 cost, certainly not , air groups count as armament therefore would exceed 2% => Cost 100%.

"A 12,000t oiler costs $3 & 3BP (armament 2% max) with mercantille rules.
If you rebuild it as an aircraft carrier, its weight will be a maximum of 12000t, its additional cost will be 9$ & 9BP."

[Kaiser Kirk]

This has been quiet for a couple days, so I'll try to write a considered post tomorrow (Weds) to move the conversation forward :)

[Kaiser Kirk]

So I was up for watching TV and playing with the Naval Artillery tool,
but not for reading/digesting/ and replying to the carrier discussion.

The following table might be a little hard to understand...at least in the preview the columns are all offset.
the key part is the middle with the KG Short and Shortfall columns.

The KG short is the shortfall between the N7 max allowed shell weight, and the historical
weights. As you can see, there really is not a shortfall.

the Shortfall is just the ME needed for the historical gun, vs. the ME provided on the chart.

I was only looking at the last generation of Pre-WWII guns,
with the Italian and French being earlier in the 1930s.

There seems to be a consistent shortfall for guns over 12"
of roughly 83% of the ME they should have.
0.83 * 1.2 = 0.996

That is consistent with my having noted that the current 12"- MR numbers seem "high"

In My Opinion :
A 1937 tech allowing 20% more ME for guns of 311mm+ seems in order.
A 1942 tech would then add Automatic for guns 210mm -




        Historic                                        Navalism 7                   
        KG    LBS            Date of Design                            KG    Lbs           
Gun    Cal    Shell        MV    ME            KG short    Shortfall        Actual Cal    max cal    Max Shell +20%        ME    MV   
USN 16"    50    1227    2700    739    7886    1939        99%    83%        50    60    1221    2686    6550    673   
USN 16"    45    1227    2700    701    7100    1936        99%    83%        45    60    1221    2686    5895    639   
USN 14" mk11    50    682    1500    823    5470.5    1937        110%    86%        50    60    753    1656    4725    728   
12    50    518    1140    762    3562.5    1939        99%    105%        50    60    515.1    1133    3750    859   
RN 16    45    1080    2375    747    7139.5    1938        113%    83%        45    60    1221    2686    5895    639   
                                                                   

[Kaiser Kirk]

Trying to get back to the carrier discussion.

Conversions - I rather like Jefgte's take.
You can take an 'Aux' Hull that is existing, and just pay the additional build cost to 'convert' to a carrier?

Still the air group penalty present, reducing potential airgroup and making building a warship in the beginning more appealing.

Long ago I came up with a standard "Hog Island" freighter, but as we will have to invent rules for taking ships out of the merchant marines as well. It is likely also overdue to come up with some more "stock" merchant vessels.

I will note that with the idea of fairly isolationist neutrals and without the tremendous US economy and commerce with Europe, I expect there are far far fewer ocean liners in existence. "Cargo-liners" would likely be the more common vessel.

reduced hull strength
We see with Ranger, Wasp, Ryujo, Colossus, and famously Independence classes efforts to build carriers with lighter hull girders.
However, many of these also had reduced stores - Colossus being the exception.

How about adding to the 1938 carrier tech "Carriers can be built to cruiser hull standards.".
?

[Kaiser Kirk]

The following is basically semi-random notes I've made examine various books and sites.


20000yds – eff spotting  = 18,282m

Technology introduction

1922 -planned 2 ftr, 1 spotter, 1 top bomber per dn
1922 - 1st compressed air catpult
1937 – shinsu maru – stern ramp, side doors
lvp -higgins – late 30s
lca-
1939 - HFDF – direction finding
1941-iff transponder
1941- fighter catapult ships CAM
1942 – hull weights reduced 18% since 1908 – better & more rational framing, welding
1943 – general board reviewed & approved automatic-gun cruisers

1907 – Bulbous bow introduced USS Delaware.
Taylor's towing tests with ram bow models detected a resistance reduction, leading to his work on a more effective version. They work better for broader hull forms with U shaped rather than V shaped hulls, at a certain Speed : Length relationship. The following Ini bow was introduced in 1962, and works for a wider range.  Sadly, neither setting does anything in SS2.

Tidbit : Queen Elizabeth's reconstruction was ....Designed to extend its service life by fifteen years
Fits with Reconstruction/Refurbishment being for 12-15 years.

Baltimore cruisers in ww2
1st laid 31 May 1934.

37.6%  16-18 kts
28.4% 18-20 kts
1.6% 25-32knts

hull stresses 9.5-10 tons/psi, vs 8.9 for Quincy/
reduced to 60days stores from 90
"the light construction necessary to keep the prototype Brooklyn class within the 10,000 ton treaty limit has led to a greater number of lost bows than we expected"

Steam plants
Brooklyn : 700degrees/565psi
Older ships : 648/400psi
Cleveland : 850/565psi

1929 Salt Lake City – 107,000shp, 1765engine wt : 60.62 shp/t
1934 New Orleans class -107,000sh, 1970.15engine wt. : 54.3 SHP/T
1938 Brooklynn class – 100,000shp, 1792 : 55.80 SHP/T
1939 Cleveland : 90,000 ihp 1600 : 56.25 ihp/t

New Orleans Class
-had 5.75"side, 2.125"top magazine boxes , and thin belts over machinery 2.25 (equiv 2.6") side, 1" deck, 1.25" end belt+25mm hull

*Wide use of welding*

Brooklyns
42ft deep hull, stern aviation
"Armor on scale of New Orleans, with vitals proof against 6-inch fire at a 90-degree angle from 10,000 yards out".  Per pg 194, that is 5.5"
pg194-floatplaneloc, La Glassoine mattress


Eirie Class development
Preferred 4 singles over 2 twins.
Estimated Twins only fired 1.5 times faster than singles....

N7 #s – Single = 100%,   Twin = 2*0.8 = 1.6, so close.

Transom

Great Britain: HMS Vanguard (1945), HMS Swiftsure (1943)

United States: nearly all cruisers following (and derived from) USS Brooklyn(1936)

France: Gloire-class cruisers (1935)

Germany: K-Class Light Cruisers (1927)

The minelaying cruiser Adventure was laid down November 1922 launched in 1924.
So effectively a 1923 vessel.
BUT while a transom was used for propulsive efficiences, it sucked the mines in behind the ship.
So that was not fully understood.

The 1927 Konigsberg class has what looks like a transom, but none of the descriptions mention it a design feature. Perhaps this was not a true transom? Further, if it was understood, why were later German vessels without ?

So we get to Brooklyn and Gloire Classes in 1936 and 1935 respectively.


Shell Splinters
Previously I had been working from the mention about the USN that they expected the 2" armor on the 5" mounts to be proof against all BB shell splinters.  I presumed they were working from the 16" gun expectations, which would be 8 : 1.

In Nathan Okun's discussion of Bismarck's armor, he mentions you need at least 32mm to stop all 38cm blast and splinters. That is 12:1

Friedman's Cruisers Tidbits
Pensacolas and Northhamptons had a magazine box in addition to the thin belt.
Friedmans mentions intermediate radio range was to be 1000nm, but they planned to go with a shorter mast reducing range 30% to 700nm.
Further, it notes that HF long range communications were unreliable, but short and intermediate range were reliable.
Upgrading from a Cruiser squadron Flag to Fleet Flag would add 75 tons.
New Orleans heavily welded to a degree the brits were impressed by the weight savings.
Light ship weight was 9353.18

30lb plate (0.75mm) not adequate against splinters, 50-60lb (1.25-1.5") neededd

Desired flight deck length on Flight Deck Cruiser was 332 feet with an elevator forward, and 32.5knot speed. With 24 aircraft on deck, 130ft would be available to take off on.  Only 12 planes could be spotted forward while landing.

pg168 bottom – carriers large vs. small.
234 clear flight deck for fdc
130ft to fly off w 30knts over deck
sb2u-2 needed 332ft 225knts
1.25min for cat launch
2.5-3min for elevator

spotting
omaha rof 3.5rpg when spotting.

"It had to be admitted that the 8-in gun would be superior at long ranges, both because of it's better range and because of its larger splashes would be easier to spot. However, it could be argued that such ranges would rarely be achieved, given average conditions of weather and light and that the use of aircraft for spotting tended to equalize results between 6- and 8- guns. Since few hits would be made at very long range anyhow, cruisers would normally choose to close to ranges at which the superior volume of fire from the 6-inch gun cruiser would be felt."

pg 181 - speed

Armor Effectiveness
5" for 1,000lb bomb from 10,000ft
2" for 500lb from 11,000ft
2.4" for 1,000 from 10,000ft
.9" for 50cal strafing

Decapping :
Roughly 20% of shell diameter to decap.
From Okun's chart, it looks like 17% is needed to decap.

Misc wt and fittings
75t for Admiral's fittings
90ft for aircraft catapult
Catapult +1 boat handling crane : 125t
Catapult +1 boat handling crane : 175t
Catapult = 70t?
11.6t   SP Fighter Control Radar
5t   Radar countermeasures gear

[Jefgte]

How about adding to the 1938 carrier tech "Carriers can be built to cruiser hull standards.".
?

The method will consist of making the SS of the cruiser with its 150, 180 or 230 guns, then presenting the SS of the cruiser transformed into a CVE.

=> Ditto for a fast AC or BB transformed to CV. (USS Lexington, HMS Glorious)

[Kaiser Kirk]

How about adding to the 1938 carrier tech "Carriers can be built to cruiser hull standards.".
?

The method will consist of making the SS of the cruiser with its 150, 180 or 230 guns, then presenting the SS of the cruiser transformed into a CVE.

=> Ditto for a fast AC or BB transformed to CV. (USS Lexington, HMS Glorious)

Obviously, I need to rephrase what I meant.
That is why we have these discussions :)

I meant built from the keel up with a hull with less than 1.0 when under certain tonnage limits, just like a cruiser.

edit : The Fast AC/BB transformed is already covered in the Aviation ship rules.
You simple refurbish, but there is a penalty to allowed air group size to mimic the smaller airgroups such ships had relative to keel-up construction.

[Kaiser Kirk]

Decapping :
Roughly 20% of shell diameter to decap.
From Okun's chart, it looks like 17% is needed to decap.

Rocky, I could swear we had a different conversation somewhere, where you may have chosen to use the 20%. searching for 'decapping' in meeting room this pops up, and fits with my 17% usage.

[The Rock Doctor]

It's possible we did.

Given that I only have one class building with a decapping plate, I might just go back and adjust how much of the belt I allocated to the belt and how much was for the decapping plate.

[Kaiser Kirk]

I think that's perfectly reasonable.
If we had a discussion and the players wanted 20%, I'd want to do the same on my 1 or 2 classes with one.

[Kaiser Kirk]

Early (1932) and Advanced (1942) Deck Parks

So I wrote up something on this in the Parthian ship thread and lost it. And the carrier. Argh.

So...I can't find anywhere we specified what the "Early" vs. "Advanced" meant.
I think we were going to revisit it later.

For "Advanced" I think the model would be the British carriers as we can find what airgroups they had early war, as designed, and what airgroups they had late war, in the Pacific- and fitting the 1942 tech timeframe.

https://www.armouredcarriers.com/hms-indomitable-lessons-learned

Has a quote :
The upper hangar ... accommodated thirty aircraft. The lower hangar ... stowed fifteen aircraft. The ship, as designed, therefore carried sixty-five aircraft - forty five in the hangars and twenty in the park on the flight deck.

A key point was the Indomitable class had a full upper hanger and a half lower hanger.
Hence why the 30/15 split quoted.
So by our rules, they would be a 60 plane double hanger ship.
That would be 60 * 65 = 3900
While a single hanger vessel would be 3900 / 77 = 50

So either the Deck Park expanded the Airgroup by 33% (double hanger) or by 40% (single hanger).

The Flight Deck space would not scale by number of hangers, but would better reflect the single hanger space.

So Advanced = +40% Single Hanger Airgroup  ....seems logical and defensible.
but then you have to redo the calculation for just the deck park. Which is messy.

Alternately Advanced would be a more conservative : +33% airgroup. 
Which is Simpler, and close enough to be defensible. And so very attractive.
So I like that one.

What is Early ?
1/2 "Advanced"?
1/3rd?
1/4th?

Edit : For that matter - What do we use for "Improved" ?

Opinions, historical examples to draw from?