US Fast Battleship Scheme C 1918

Syzmo

Post subject: US Fast Battleship Scheme C 1918

Posted: March 14th, 2014, 12:02 am

Posts: 285
Joined: August 13th, 2011, 4:03 am
Location: Baltimore MD

I have been very happy to see the number of real life US dreadnoughts and "what if there was no Washington Treaty" BBs popping up lately and I was inspired to start my own, based on CanisD's drawing (do I credit him in the SB drawing?) of a springstyle plan for Scheme C of a proposed fast BB for the USN.

I believe this design would have been the starting point for a follow up class for both the South Dakota and the Lexington. With the "standard battleship" speed of 21 knots already negated by both the 23kt sodaks and the 33kt lexs, as well as the worldwide trend towards fast BBs especially in Britain and Japan a 30kt fast battleship in the US Navy is not too much of a stretch. Otherwise this ship shares most of its design features with contemporary standard BBs and CCs.

Once this drawing is squared away I intend to post a picture of what I believe this ship would have looked like if she was built in the 1920's so feel free to comment on the actual design in addition to my drawing.

[ img ]

Proposed Fast Battleship Sceme C, United States Battleship laid down 1919

Displacement:
50,009 t light; 52,877 t standard; 54,500 t normal; 55,798 t full load

Dimensions: Length overall / water x beam x draught
924.00 ft / 900.00 ft x 106.00 ft x 32.40 ft (normal load)
281.63 m / 274.32 m x 32.31 m x 9.88 m

Armament:
12 - 16.00" / 406 mm guns (4x3 guns), 2,048.00lbs / 928.96kg shells, 1919 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, 1919 Model
Breech loading guns in casemate mounts
on side, evenly spread, 8 raised mounts
4 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1919 Model
Breech loading guns in deck mounts
on side, evenly spread, all raised mounts
4 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1919 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 26,358 lbs / 11,956 kg
Shells per gun, main battery: 120
8 - 21.0" / 533.4 mm above water torpedoes, 2 - 21.0" / 533.4 mm submerged torpedo tubes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 12.0" / 305 mm 540.00 ft / 164.59 m 17.50 ft / 5.33 m
Ends: 8.00" / 203 mm 320.00 ft / 97.54 m 8.00 ft / 2.44 m
40.00 ft / 12.19 m Unarmoured ends
Main Belt covers 92 % of normal length
Main belt does not fully cover magazines and engineering spaces

- Torpedo Bulkhead:
0.10" / 3 mm 540.00 ft / 164.59 m 16.00 ft / 4.88 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 16.0" / 406 mm 9.00" / 229 mm 12.0" / 305 mm

- Armour deck: 5.00" / 127 mm, Conning tower: 16.00" / 406 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 170,973 shp / 127,546 Kw = 30.00 kts
Range 8,000nm at 10.00 kts
Bunker at max displacement = 2,921 tons

Complement:
1,783 - 2,318

Cost:
£11.712 million / $46.847 million

Distribution of weights at normal displacement:
Armament: 3,295 tons, 6.0 %
Armour: 16,856 tons, 30.9 %
- Belts: 5,645 tons, 10.4 %
- Torpedo bulkhead: 32 tons, 0.1 %
- Armament: 4,125 tons, 7.6 %
- Armour Deck: 6,558 tons, 12.0 %
- Conning Tower: 496 tons, 0.9 %
Machinery: 6,071 tons, 11.1 %
Hull, fittings & equipment: 23,738 tons, 43.6 %
Fuel, ammunition & stores: 4,491 tons, 8.2 %
Miscellaneous weights: 50 tons, 0.1 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
60,755 lbs / 27,558 Kg = 29.7 x 16.0 " / 406 mm shells or 5.2 torpedoes
Stability (Unstable if below 1.00): 1.08
Metacentric height 6.3 ft / 1.9 m
Roll period: 17.7 seconds
Steadiness - As gun platform (Average = 50 %): 51 %
- Recoil effect (Restricted arc if above 1.00): 0.83
Seaboat quality (Average = 1.00): 1.02

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.617
Length to Beam Ratio: 8.49 : 1
'Natural speed' for length: 30.00 kts
Power going to wave formation at top speed: 48 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 40.60 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 28.00 ft / 8.53 m
- Forecastle (22 %): 25.00 ft / 7.62 m
- Mid (50 %): 21.00 ft / 6.40 m
- Quarterdeck (20 %): 18.25 ft / 5.56 m
- Stern: 18.25 ft / 5.56 m
- Average freeboard: 21.74 ft / 6.63 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 102.5 %
- Above water (accommodation/working, high = better): 151.7 %
Waterplane Area: 70,896 Square feet or 6,586 Square metres
Displacement factor (Displacement / loading): 98 %
Structure weight / hull surface area: 243 lbs/sq ft or 1,188 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.11
- Longitudinal: 0.96
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent

_________________
"All men dream, but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find that it was vanity, but the dreamers of the day are dangerous men, for they may act their dreams with open eyes, to make it possible. This I did." Thomas Edward Lawrence, The Seven Pillars of Wisdom

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US Fast Battleship Scheme C 1918

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