Gas turbine propulsion

I am curious to know about naval gas turbine propulsion. I have heard from a knowledgeable source that the power output of turbines might be able to be increased considerably beyond the nominal figures. We now have some quite large naval ships, such as the new American helicopter carriers, that are gas turbine powered. We could be talking 40,000 ton or larger ships. If we want to speculate about maximum speeds, we would need to have some idea about what is possible.

Lou Coatney has more drawings of the same sort

If you have a need, these are really useful. Lou Coatney points out on the NavWarGames Yahoo Group that he has even more of the ONI ship drawings.

Lou Coatney has ONI WWII ship drawings

Thanks to Paolo Disalvo, on the NavWarGames Yahoo Group, I found out about Lou Coatney's page of links to the U.S.Navy ONI WWII ship drawings.

More about the Makin Island

I wondered if by lightening the ship if the Makin Island could make a higher speed than 25 knots. I was not very successful, but I thought that I would make the Springsharp report available to those who are interested. I did not attempt to do anything except get a reasonably good speed for the dimensions, power, number of shafts, and displacement. I didn't attempt to deal with the actual ship configuration:

Makin Island, United States LHD laid down 1950

Displacement:
 35,420 t light; 36,197 t standard; 38,843 t normal; 40,960 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (808.09 ft / 780.00 ft) x 106.00 ft x (27.00 / 28.17 ft)
 (246.31 m / 237.74 m) x 32.31 m  x (8.23 / 8.58 m)

Machinery:
 Diesel Internal combustion motors, 
 Geared drive, 2 shafts, 70,363 shp / 52,491 Kw = 25.46 kts
 Range 9,500nm at 15.00 kts
 Bunker at max displacement = 4,762 tons

Complement:
 1,383 - 1,798

Cost:
 £11.535 million / $46.139 million

Distribution of weights at normal displacement:
 Armament: 0 tons, 0.0 %
 Machinery: 1,683 tons, 4.3 %
 Hull, fittings & equipment: 33,737 tons, 86.9 %
 Fuel, ammunition & stores: 3,423 tons, 8.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   358,561 lbs / 162,641 Kg = 3,320.0 x 6 " / 152 mm shells or 29.2 torpedoes
 Stability (Unstable if below 1.00): 1.05
 Metacentric height 6.0 ft / 1.8 m
 Roll period: 18.1 seconds
 Steadiness - As gun platform (Average = 50 %): 100 %
   - 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,
   an extended bulbous bow and large transom stern
 Block coefficient (normal/deep): 0.609 / 0.616
 Length to Beam Ratio: 7.36 : 1
 'Natural speed' for length: 32.28 kts
 Power going to wave formation at top speed: 44 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 30.00 degrees
 Stern overhang: 5.00 ft / 1.52 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 20.00 %,  40.00 ft / 12.19 m,  40.00 ft / 12.19 m
    - Forward deck: 30.00 %,  40.00 ft / 12.19 m,  40.00 ft / 12.19 m
    - Aft deck: 35.00 %,  40.00 ft / 12.19 m,  40.00 ft / 12.19 m
    - Quarter deck: 15.00 %,  40.00 ft / 12.19 m,  40.00 ft / 12.19 m
    - Average freeboard:  40.00 ft / 12.19 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 16.0 %
  - Above water (accommodation/working, high = better): 350.2 %
 Waterplane Area: 63,568 Square feet or 5,906 Square metres
 Displacement factor (Displacement / loading): 1,000 %
 Structure weight / hull surface area: 343 lbs/sq ft or 1,674 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 2.40
  - Longitudinal: 6.34
  - Overall: 2.64
 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

The Makin Island (LHD-8)

I was interested in seeing some photographs of the new amphib, Makin Island (LHD-8). From some angles, the ship seems pretty warlike and impressive. Wikipedia is saying that the ship can only make 20 knots, but gives the dimensions and the power. The ship is about 780ft LWL x 106ft x 27ft. A reasonable normal displacement is 41,000 tons. With power of 70,000 SHP, I thought that a higher speed should be possible. I ran an experiment with Springsharp and it seems that the ship, at about 41,500 tons should be able to make 25 knots.

I was interested in the story behind the ship name, and Carlson's Raiders attack on Makin Island in 1942. The Nautilus and Argonaut seem to have been originally intended as cruiser submarines when they were designed. The German success with cruiser submarines in the Great War seemed to argue for the type having usefulness, but the Japanese were the only great power to have any success at all with the type after 1918.