Requests of Indochinese Navy

Started by ciders, September 14, 2010, 01:42:19 PM

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Kaiser Kirk

Quote from: Guinness on September 15, 2010, 09:32:52 AM

So for me, I've abandoned SS's seakeeping value for ships I design under the TB/DD rules entirely, and instead think in terms of deck heights and structural strength.


The issue I see here is that the 1920 Rules Changes (advanced draft) thread didn't mention this becoming official, or any official means of adjudicating how acceptable seakeeping will be determined. Until then the 'seakeeping' stat is all we have.  So if we start willy nilly building TBs with horrid seakeeping on this premise, do we risk a War-mod deciding 'gee these things barely float, only usable in dead calms'.  ?
Did they beat the drum slowly,
Did they play the fife lowly,
Did they sound the death march, as they lowered you down,
Did the band play the last post and chorus,
Did the pipes play the flowers of the forest

Logi

I try to think in terms of bow wave crest and trough, traverse wave length, and the proportional scaling down the wave as going along. I try if the ship's freeboard is above the bow wave crest (as well as the crest of the waves in the general area) it can move through the wave. Especially it the speed/length ratio is between 0.94 and 1.34 so that the hull does not climb and fall down waves.

The TB design by Guinness going at 34kts creates a bow wave of 7.46'. The bow height is 9.51'. Granted it might get a bit iffy driving through seas with above 2' wave heights, but it should be able to float and move around quite well. Terrible working conditions aside, it should be able to withstand even higher waves without sinking.

Carthaginian

The Confederate entry has the size, speed and firepower that you're looking for.
*does Jedi mind trick*
34.25 knots top speed, 2000+ mile range @ 15 knots and a triple 21" torpedo launcher
Seakeeping should be fine for coastal applications in the South Pacific.
The guns would be built to order from II plans.

Quotelaid down 1920

Displacement:
   300 t light; 308 t standard; 350 t normal; 384 t full load

Dimensions: Length overall / water x beam x draught
   230.00 ft / 225.00 ft x 20.00 ft x 6.00 ft (normal load)
   70.10 m / 68.58 m x 6.10 m  x 1.83 m

Armament:
     1 - 2.95" / 75.0 mm guns in single mounts, 13.23lbs / 6.00kg shells, 1920 Model
     Quick firing gun in deck mount
     on centreline forward
     4 - 0.50" / 12.7 mm guns in single mounts, 0.05lbs / 0.02kg shells, 1920 Model
     Machine guns in deck mounts
     on side, all amidships
   Weight of broadside 13 lbs / 6 kg
   Shells per gun, main battery: 100
   3 - 21.0" / 533.4 mm above water torpedoes

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 12,500 shp / 9,325 Kw = 30.06 kts
   Range 2,050nm at 15.00 kts
   Bunker at max displacement = 75 tons

Complement:
   39 - 52

Cost:
   £0.092 million / $0.366 million

Distribution of weights at normal displacement:
   Armament: 2 tons, 0.5 %
   Machinery: 192 tons, 54.8 %
   Hull, fittings & equipment: 101 tons, 28.9 %
   Fuel, ammunition & stores: 50 tons, 14.2 %
   Miscellaneous weights: 6 tons, 1.7 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     91 lbs / 41 Kg = 7.0 x 3.0 " / 75 mm shells or 0.1 torpedoes
   Stability (Unstable if below 1.00): 1.19
   Metacentric height 0.6 ft / 0.2 m
   Roll period: 10.7 seconds
   Steadiness    - As gun platform (Average = 50 %): 50 %
           - Recoil effect (Restricted arc if above 1.00): 0.05
   Seaboat quality  (Average = 1.00): 0.61

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.454
   Length to Beam Ratio: 11.25 : 1
   'Natural speed' for length: 15.00 kts
   Power going to wave formation at top speed: 71 %
   Trim (Max stability = 0, Max steadiness = 100): 82
   Bow angle (Positive = bow angles forward): 22.60 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:        12.00 ft / 3.66 m
      - Forecastle (20 %):    9.00 ft / 2.74 m
      - Mid (50 %):        8.00 ft / 2.44 m
      - Quarterdeck (15 %):    7.00 ft / 2.13 m
      - Stern:        7.00 ft / 2.13 m
      - Average freeboard:    8.27 ft / 2.52 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space    - Hull below water (magazines/engines, low = better): 182.1 %
       - Above water (accommodation/working, high = better): 60.5 %
   Waterplane Area: 2,879 Square feet or 267 Square metres
   Displacement factor (Displacement / loading): 39 %
   Structure weight / hull surface area: 19 lbs/sq ft or 93 Kg/sq metre
   Hull strength (Relative):
       - Cross-sectional: 0.50
       - Longitudinal: 1.28
       - Overall: 0.55
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is cramped
   Caution: Lacks seaworthiness - very limited seakeeping ability

34.25 knots trial speed
So 'ere's to you, Fuzzy-Wuzzy, at your 'ome in old Baghdad;
You're a pore benighted 'eathen but a first-class fightin' man;
We gives you your certificate, an' if you want it signed
We'll come an' 'ave a romp with you whenever you're inclined.

Logi

I like this one better, seems to have enough bow height and length to ensure a relatively smooth ride.