Shipbucket

Krakatoa, Had a go at doing the sums (using a mix of navweps and springsharp).

It depends what guns you use for the 11' you have 2 options the PB 280mm/52(11') or the S&G 280mm/54.5(11') and you have to guess for the 350mm(13.75') (I have assumed 50cal and shell weight of 600kg (1930) but you might go for 55cal and 660kg but that will make the number even bigger) as the only ones are WW1 and they would probably have built a better new gun.

So number. (all installations have 9 guns in 3 triples, I have gone with the same protection 12' face 5' sides/roof 12' Barbette in all cases, all number in t)

Gun weight = 414 /437 /659
Mounts = 938 / 992 /1367
Armour = 300 / 300 /409
Total = 1,652 / 1,730 / 2,773 So just the turrets are 1043t more and that's all high up. (38%)

Shell mags is complicated as the guns all OTL used different number of shells
Shell number = 120 / 150 / 90
Shell weights = 397 / 546 / 595 , but I'm not sure that 90 rounds for a raider is sensible so here it is with all guns with 120 shells (IMO minimum I would want)
Shells weights (120) = 397 / 437 / 794 (= +357t for the 35cm guns or 45%) this is nearly double in size so you will have to add in much more belt weight.....

The difference is massive and I think you will have to ether drop to 6 guns (OTL 15' modification style) or make the ship much bigger.
(I'm not sure but are there not rules of thumb that weapons should not be more than 1/3 or 1/10 of a ship ? We are talking about adding 2000+t and 1/2 of that high up in the ship, IMO it would add 30%+ to the ships displacement ?)

I think it depends what you want 9x11' will be better v CAs but 6x 13.8' would be better v a BB (IMO) but it would scare the RN so may not work with rearmament especially if the RN thinks it will be limited to 12' guns on some of its BBs (the lighter ones that it would like to use to balance the Germans in Europe rather than v Nagato ?) ?

JSB

ADD Re the 6 x 35cm v 9x 280cm/54.5
guns 513/437
mount 1,063/ 992
Ar 309/300
mag 529/ 437
toatl = 1,985 / 1,730
So close (255t) and may work without the changes needed for the 15' conversion in OTL

I'm numerically dyslexic so I'll have to leave the calculations to you superior beings.
JSB has done more than I could even contemplate.

K and JSB. Weight is not the end of the story. Stability matters and it's weight x square of distance above centre of buoyancy (or below) that counts. I suspect your ship K may become unstable as you fire off the ammunition. Ships roll in heavy seas, when any turning moment can have greater effect. Of course, if you stick to normal practice and replace turrets with others weighing the same (fewer if larger barrels) you can worry less about such things.

I was not trying to pass off the Gneisenau as the finished deal, just that it was possible to do the changeover, I did not want to have to do a complete rebuild just to satisfy everyones cravings, I said right at the start of the preamble for that drawing that all I had changed was the barrels and added a 37mm mounting - that was it, nothing else. I keep saying it. Stop criticising - start drawing, if you think it is wrong - draw it right. If you want to offer criticisms also offer solutions. And yes Rusel us "Superior Beings" who actually do drawings do deserve some respect not just criticisms.

To actually build S&G with 13.8" would require about 15 feet of extra length and 4-5 feet of extra beam, displacement would also rise. Turrets could remain the same with larger guns fitted. I had a look at Navweaps and the magazine and handling equipment would not require much, the problem would be to alter the hoists and handling equipment to raise 600kg not 300kg. The longest 13.8" shell is 54 inches, the longest 11" is 50.5 inches. So the magazines would also not require too much alteration to ship the 13.8" in place of the 11". There is no reason why that when the ammunition is being shot away at 12,000lbs a salvo that 'counterflooding' of some kind can be used to maintain stability. Think of the 15/16" battleships who also do not have a lot of reserve buoyancy, shooting away their ammunition, I am sure they would have to have something to maintain stability as well.

Remember we would not be rebuilding the S&G, they would be designed with 13.8" from scratch.

The change from 11" to 13.8" may well be possible. What is not possible is to prove whether it will or not by simply calculating weight changes and ignoring stability. "4-5 feet of extra beam" goes a long way to dealing with any such problems. As a guide, when HMS Exeter was to be approved, she was expected to be about 130tons more than the approved 8400tons for HMS York, largely due to gun turrets some 90tons heavier than initially planned, and changes to the bridge [not the later change to a streamlined tower]. These extra weights 'high up' were compensated for by increasing the beam from 57' to 58'. That more of that extra weight was forward had to be compensated by shifting fuel storage aft, and bringing other lighter stores forward, but that meant some inflammable liquids would have to be stored above the waterline. Nothing of that would show in a profile drawing. In the end, about 200tons was saved during construction.

So I have finished my American 25000 ton battleship. I have went back and forth with cruiser like ships to the early concepts of the Alaska and none of them worked. So I looked in my copy of Friedmans US Battleships and looked at some of the 1928-34 battleships design, and I have made a version using some of the designs from there, and it works.

I present to you the USS North Carolina as designed in 1934:


USS North Carolina, USA, Battleship, laid down in 1936

Displacement:
23 691 t light; 24 630 t standard; 25 600 t normal; 26 376 t full load

Dimensions: Length overall / water x beam x draught
709,00 ft / 689,00 ft x 101,50 ft x 30,00 ft (normal load)
216,10 m / 210,01 m x 30,94 m x 9,14 m

Armament:
9 - 12,00" / 305 mm guns (3x3 guns), 864,00lbs / 391,90kg shells, 1936 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, majority forward, 1 raised mount - superfiring
10 - 5,00" / 127 mm guns (5x2 guns), 62,50lbs / 28,35kg shells, 1936 Model
Dual purpose guns in deck mounts with hoists
on side, all amidships
16 - 1,10" / 27,9 mm guns (4x4 guns), 0,67lbs / 0,30kg shells, 1936 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 8 412 lbs / 3 815 kg
Shells per gun, main battery: 90

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 12,0" / 305 mm 440,50 ft / 134,26 m 13,00 ft / 3,96 m
Ends: Unarmoured
Main Belt covers 98 % of normal length

- Torpedo Bulkhead:
4,00" / 102 mm 440,50 ft / 134,26 m 10,00 ft / 3,05 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 11,0" / 279 mm 5,00" / 127 mm 10,0" / 254 mm

- Armour deck: 5,00" / 127 mm, Conning tower: 10,00" / 254 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 73 844 shp / 55 088 Kw = 27,00 kts
Range 10 000nm at 10,00 kts
Bunker at max displacement = 1 746 tons

Complement:
1 011 - 1 315

Cost:
£10,558 million / $42,234 million

Distribution of weights at normal displacement:
Armament: 1 051 tons, 4,1 %
Armour: 9 532 tons, 37,2 %
- Belts: 2 955 tons, 11,5 %
- Torpedo bulkhead: 652 tons, 2,5 %
- Armament: 1 685 tons, 6,6 %
- Armour Deck: 4 053 tons, 15,8 %
- Conning Tower: 187 tons, 0,7 %
Machinery: 2 072 tons, 8,1 %
Hull, fittings & equipment: 11 035 tons, 43,1 %
Fuel, ammunition & stores: 1 909 tons, 7,5 %
Miscellaneous weights: 0 tons, 0,0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
49 391 lbs / 22 403 Kg = 57,2 x 12,0 " / 305 mm shells or 9,1 torpedoes
Stability (Unstable if below 1.00): 1,13
Metacentric height 6,4 ft / 2,0 m
Roll period: 16,8 seconds
Steadiness - As gun platform (Average = 50 %): 84 %
- Recoil effect (Restricted arc if above 1.00): 0,49
Seaboat quality (Average = 1.00): 1,68

Hull form characteristics:
Hull has raised forecastle, rise aft of midbreak
Block coefficient: 0,427
Length to Beam Ratio: 6,79 : 1
'Natural speed' for length: 26,25 kts
Power going to wave formation at top speed: 46 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 23,72 degrees
Stern overhang: 5,50 ft / 1,68 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 33,00 ft / 10,06 m
- Forecastle (20 %): 28,00 ft / 8,53 m (27,00 ft / 8,23 m aft of break)
- Mid (50 %): 18,00 ft / 5,49 m (27,00 ft / 8,23 m aft of break)
- Quarterdeck (15 %): 18,00 ft / 5,49 m
- Stern: 20,50 ft / 6,25 m
- Average freeboard: 23,51 ft / 7,17 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 71,9 %
- Above water (accommodation/working, high = better): 185,8 %
Waterplane Area: 43 820 Square feet or 4 071 Square metres
Displacement factor (Displacement / loading): 116 %
Structure weight / hull surface area: 175 lbs/sq ft or 855 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,93
- Longitudinal: 1,87
- 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

That looks really good Karle94, I just love that split twin/single funnel.

Springsharp for these ships seems to be showing very similar results for size of hull, displacement, even armament. It is only those designs where we have added in a bit of a cheat factor that come out bigger and better armed.

This is an American ship, there is no cheat factor It is a twin funnel, joined at the cap ala SoDak. You can see it here: https://dl.dropboxusercontent.com/u/939 ... 1934-3.png

I am not entirely certain if that set of funnels matches battleship powerplants. it looks small to me, but I might be wrong.
I would suggest some air vents or intakes for the machinery spaces and boilers
other then that, looks good, and may I congratulate you with an, as far as I can see on first glance, spot on set of hull shading

_________________
Drawings are credited with J.Scholtens
I ask of you to prove me wrong. Not say I am wrong, but prove it, because then I will have learned something new.
Shipbucket Wiki admin

Looks very nice, a few Q if you don't mind.
- what date is it ? 34 or 36 ?
- would it be worth moving the stern 1.1' guns to get them free of blast ? and improve the 5' arcs ?
- is that 2 or one funnel ?

Re Krakatoa,
I agree but I would put that against the fact that Spring sharp doesn't factor in nationality and therefore different construction standards like welding or the massive use of STS steel that might save weight in return for more money.

JSB