WesWorld

Here is my design for a huge oil tanker built in memory of the first tanker of the same name (Knock Nevis ) and scapped as Mont in 2010. Feel free to comment on the design.


Knock Nevis II, United States World's Largest Oil Tanker

Displacement: 496,683 t light; 507,997 t standard; 565,714 t normal; 611,888 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(1,616.00 ft / 1,600.00 ft) x 220.00 ft x (75.00 ft / 80.34 ft)
(492.56 m / 487.68 m) x 67.06 m x (22.86 m / 24.49 m)

Machinery:
• Diesel Internal Combustion Motors,
• Direct drive, 4 shafts, 436,000 shp = 27.37 kts
• Range 40,000nm at 16.00 kts
• Bunker at max displacement = 103,891 tons (Diesel Oil)

Typical Complement: 20

Cost: £147.327 million / $589.309 million

Distribution of weights at normal displacement:
• Machinery: 10,431 tons, 1.8 %
• Hull, fittings & equipment: 121,252 tons, 21.4 %
• Fuel, ammunition & stores: 69,031 tons, 12.2 %
• Miscellaneous weights: 365,000 tons, 64.5 %
o Hull below water: 150,000 tons
o Hull above water: 100,000 tons
o On freeboard deck: 95,000 tons
o Above deck: 20,000 tons

Overall Survivability and Seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,082,976 lbs / 491,230 Kg = 10,027.6 x 6 " / 152 mm shells or 21.4 torpedoes
Stability (Unstable if below 1.00): 1.21
Metacentric height 23.1 ft / 7.0 m
Roll period: 19.2 seconds
Steadiness - As gun platform (Average = 50 %): 80 %
- Recoil effect (Restricted arc if above 1.00): 0.00
Seaboat quality (Average = 1.00): 2.00

Hull Form Characteristics:
Hull has a flush deck,
a straight bulbous bow and small transom stern
Block coefficient (normal/deep): 0.750 / 0.757
Length to Beam Ratio: 7.27 : 1
'Natural speed' for length: 42.94 kts
Power going to wave formation at top speed: 35 %
Trim (Max stability = 0, Max steadiness = 100): 40
Bow angle (Positive = bow angles forward): 5.27 degrees
Stern overhang: 10.00 ft / 3.05 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20.00 %, 65.00 ft / 19.81 m, 60.00 ft / 18.29 m
- Forward deck: 30.00 %, 60.00 ft / 18.29 m, 60.00 ft / 18.29 m
- Aft deck: 35.00 %, 60.00 ft / 18.29 m, 60.00 ft / 18.29 m
- Quarter deck: 15.00 %, 60.00 ft / 18.29 m, 60.00 ft / 18.29 m
- Average freeboard: 60.40 ft / 18.41 m

Ship Space, Strength and Comments:
Space - Hull below water (magazines/engines, low = better): 55.0 %
- Above water (accommodation/working, high = better): 335.6 %
Waterplane Area: 302,804 Square feet or 28,131 Square metres
Displacement factor (Displacement / loading): 147 %
Structure weight / hull surface area: 282 lbs/sq ft or 1,375 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.97
- Longitudinal: 1.30
- Overall: 1.00
Excellent machinery, storage, compartmentation space
Excellent accommodation and workspace room
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, rides out heavy weather easily

I don't think a tanker would care 115,000 tons of cargo on or above the deck...

This design has way way too much power. You could easily do with 1/4th of what you've got now.
Top speed shouldn't be more than 18kts at most, 16kts is more likely. And on commercial ships like this top speed is their cruise speed.