I have seen several discussions and what-ifs surrounding the use of the experimental 18"/47 cal guns by the US Navy. So far I have been very silent on this subject, as the USN came to the conclusion that 18 inches as a caliber did not gain enough performance over 16 inch guns to outweigh the cons, namely increased weight and reduction of rate of fire. For a few days now, I have been thinking, and mucking about, producing a bb design of "Ultima Americana", the pinnacle of American battleship design. It has 8x18"/47 caliber gun in a traditional layout, with a very American tradition of armor over speed. The armor layout closely resembles one of the rejected designes for the New Mexico, with armor to rival the Yamato. The ship design it self is very traditional, following the Colorado more than the South Dakota class, which every BB design from 1920 to the early 30s would more or less emulate. This is also my first drawing to include the new style of 3x3 sized portholes.
As designed in 1920:
![[ img ]](https://i.imgur.com/3sJp3yl.png)
As commisioned in 1927:
![[ img ]](https://i.imgur.com/NTeP7Vn.png)
As she appeared in 1934:
![[ img ]](https://i.imgur.com/7Bxtk3P.png)
As she appeared in 1941:
![[ img ]](https://i.imgur.com/4CMuKrt.png)
As she appeared in 1942:
![[ img ]](https://i.imgur.com/eGEtguI.png)
As she appeared in early 1943:
![[ img ]](https://i.imgur.com/hm2e543.png)
USS Rhode Island, United States of America, Battleship laid down in 1926.
Displacement:
45 939 t light; 48 337 t standard; 50 676 t normal; 52 548 t full load
Dimensions: Length overall / water x beam x draught
785,50 ft / 761,00 ft x 114,83 ft x 34,72 ft (normal load)
239,42 m / 231,95 m x 35,00 m x 10,58 m
Armament:
8 - 18,00" / 457 mm guns (4x2 guns), 2 916,00lbs / 1 322,68kg shells, 1926 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
12 - 6,00" / 152 mm guns in single mounts, 108,00lbs / 48,99kg shells, 1926 Model
Breech loading guns in casemate mounts
on side, all amidships
4 - 3,00" / 76,2 mm guns in single mounts, 13,50lbs / 6,12kg shells, 1926 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 24 678 lbs / 11 194 kg
Shells per gun, main battery: 100
2 - 21,0" / 533,4 mm submerged torpedo tubes
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 18,0" / 457 mm 586,00 ft / 178,61 m 10,00 ft / 3,05 m
Ends: Unarmoured
Main Belt covers 118 % of normal length
- Torpedo Bulkhead:
3,00" / 76 mm 856,00 ft / 260,91 m 10,00 ft / 3,05 m
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 25,0" / 635 mm 14,0" / 356 mm 19,0" / 483 mm
2nd: 6,00" / 152 mm 5,00" / 127 mm -
- Armour deck: 7,00" / 178 mm, Conning tower: 19,00" / 483 mm
Machinery:
Oil fired boilers, steam turbines,
Electric motors, 4 shafts, 63 022 shp / 47 014 Kw = 23,00 kts
Range 15 000nm at 10,00 kts
Bunker at max displacement = 4 211 tons
Complement:
1 688 - 2 195
Cost:
£15,481 million / $61,926 million
Distribution of weights at normal displacement:
Armament: 3 085 tons, 6,1 %
Armour: 20 665 tons, 40,8 %
- Belts: 4 426 tons, 8,7 %
- Torpedo bulkhead: 950 tons, 1,9 %
- Armament: 6 570 tons, 13,0 %
- Armour Deck: 8 158 tons, 16,1 %
- Conning Tower: 561 tons, 1,1 %
Machinery: 2 017 tons, 4,0 %
Hull, fittings & equipment: 20 072 tons, 39,6 %
Fuel, ammunition & stores: 4 737 tons, 9,3 %
Miscellaneous weights: 100 tons, 0,2 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
74 816 lbs / 33 936 Kg = 25,7 x 18,0 " / 457 mm shells or 12,4 torpedoes
Stability (Unstable if below 1.00): 1,00
Metacentric height 6,1 ft / 1,9 m
Roll period: 19,5 seconds
Steadiness - As gun platform (Average = 50 %): 75 %
- Recoil effect (Restricted arc if above 1.00): 0,86
Seaboat quality (Average = 1.00): 1,50
Hull form characteristics:
Hull has raised forecastle, rise forward of midbreak, low quarterdeck
Block coefficient: 0,585
Length to Beam Ratio: 6,63 : 1
'Natural speed' for length: 27,59 kts
Power going to wave formation at top speed: 41 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 34,99 degrees
Stern overhang: -4,00 ft / -1,22 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 35,00 ft / 10,67 m
- Forecastle (20 %): 30,00 ft / 9,14 m (28,00 ft / 8,53 m aft of break)
- Mid (50 %): 28,00 ft / 8,53 m (18,00 ft / 5,49 m aft of break)
- Quarterdeck (15 %): 18,00 ft / 5,49 m (19,00 ft / 5,79 m before break)
- Stern: 20,00 ft / 6,10 m
- Average freeboard: 24,13 ft / 7,35 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 72,6 %
- Above water (accommodation/working, high = better): 162,7 %
Waterplane Area: 62 998 Square feet or 5 853 Square metres
Displacement factor (Displacement / loading): 102 %
Structure weight / hull surface area: 230 lbs/sq ft or 1 122 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,95
- Longitudinal: 1,50
- 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
![[ img ]](https://i.imgur.com/KA7Mfud.png)
![[ img ]](https://i.imgur.com/QhfLhqv.png)
