Friday, January 14, 2005

My first cut at the 1915 large battleship

My first design study for the German 1915 large battleship to be built in numbers was too short, but I was able to make the design work in Springsharp pretty well. The ship carried 9-18in/45 and 12-5in QF guns and was 65,000 tons. Due to the vagaries of Springsharp, I was able to drive the ship at 27 knots, not 20 knots. The biggest issue was getting sufficient stability. I had to reduce the draft by almost 4 feet and decrease armor. To actually get stability to 1.0, I had to increase the speed. 700 feet is really too short for a ship with 9-18in guns.
Ger/BB/1915 design study c1, Germany Battleship laid down 1915

Displacement:
	60,911 t light; 63,446 t standard; 65,117 t normal; 66,453 t full load

Dimensions: Length overall / water x beam x draught
	703.03 ft / 700.00 ft x 120.00 ft x 39.00 ft (normal load)
	214.28 m / 213.36 m x 36.58 m  x 11.89 m

Armament:
      9 - 18.00" / 457 mm guns (3x3 guns), 2,916.00lbs / 1,322.68kg shells, 1915 Model
	  Breech loading guns in turrets (on barbettes)
	  on centreline ends, majority forward, all raised mounts - superfiring
      12 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1915 Model
	  Quick firing guns in deck mounts 
	  on side, evenly spread, all raised mounts
	Weight of broadside 27,540 lbs / 12,492 kg
	Shells per gun, main battery: 80

Armour:
   - Belts:		Width (max)	Length (avg)		Height (avg)
	Main:	16.0" / 406 mm	420.00 ft / 128.02 m	18.00 ft / 5.49 m
	Ends:	Unarmoured
	  Main Belt covers 92 % of normal length

   - Gun armour:	Face (max)	Other gunhouse (avg)	Barbette/hoist (max)
	Main:	16.0" / 406 mm	9.00" / 229 mm		14.0" / 356 mm
	2nd:	2.00" / 51 mm	      -			      -

   - Armour deck: 8.00" / 203 mm, Conning tower: 9.00" / 229 mm

Machinery:
	Oil fired boilers, steam turbines, 
	Geared drive, 4 shafts, 148,126 shp / 110,502 Kw = 27.00 kts
	Range 4,500nm at 12.00 kts
	Bunker at max displacement = 3,007 tons

Complement:
	2,037 - 2,649

Cost:
	£8.450 million / $33.798 million

Distribution of weights at normal displacement:
	Armament: 3,443 tons, 5.3 %
	Armour: 20,623 tons, 31.7 %
	   - Belts: 5,496 tons, 8.4 %
	   - Torpedo bulkhead: 0 tons, 0.0 %
	   - Armament: 4,887 tons, 7.5 %
	   - Armour Deck: 9,926 tons, 15.2 %
	   - Conning Tower: 314 tons, 0.5 %
	Machinery: 5,611 tons, 8.6 %
	Hull, fittings & equipment: 31,234 tons, 48.0 %
	Fuel, ammunition & stores: 4,206 tons, 6.5 %
	Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
	Survivability (Non-critical penetrating hits needed to sink ship):
	  84,790 lbs / 38,460 Kg = 29.1 x 18.0 " / 457 mm shells or 5.8 torpedoes
	Stability (Unstable if below 1.00): 1.00
	Metacentric height 6.6 ft / 2.0 m
	Roll period: 19.6 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 rise forward of midbreak
	Block coefficient: 0.696
	Length to Beam Ratio: 5.83 : 1
	'Natural speed' for length: 26.46 kts
	Power going to wave formation at top speed: 57 %
	Trim (Max stability = 0, Max steadiness = 100): 50
	Bow angle (Positive = bow angles forward): 4.00 degrees
	Stern overhang: 1.00 ft / 0.30 m
	Freeboard (% = measuring location as a percentage of overall length):
	   - Stem:		29.00 ft / 8.84 m
	   - Forecastle (20 %):	28.00 ft / 8.53 m
	   - Mid (67 %):		28.00 ft / 8.53 m (20.00 ft / 6.10 m aft of break)
	   - Quarterdeck (15 %):	20.00 ft / 6.10 m
	   - Stern:		20.00 ft / 6.10 m
	   - Average freeboard:	25.44 ft / 7.75 m
	Ship tends to be wet forward

Ship space, strength and comments:
	Space	- Hull below water (magazines/engines, low = better): 67.6 %
		- Above water (accommodation/working, high = better): 161.7 %
	Waterplane Area: 67,069 Square feet or 6,231 Square metres
	Displacement factor (Displacement / loading): 110 %
	Structure weight / hull surface area: 337 lbs/sq ft or 1,646 Kg/sq metre
	Hull strength (Relative):
		- Cross-sectional: 1.29
		- Longitudinal: 2.72
		- Overall: 1.39
	Hull space for machinery, storage, compartmentation is excellent
	Room for accommodation and workspaces is excellent

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