Amazon Ad

Sunday, June 18, 2006

I underestimated the displacement necessary for the Ger/BB/1916 CDV

I have this really anachronistic drawing of a German coast defense battleship with 4-18in BLR and 16-4in QF guns. The armour basis is just 10in, with a 6in deck. The original concept is for 10in + 2in decks. Springsharp calculates that the weight would be more than 14,000 tons for a such a protection scheme, not the 10,039 tons that I had envisioned. I was able to keep the machinery weight down to around what was specified (2,170 tons). This is the Springsharp report:
Ger/BB/1916 CDV, Germany Coast Defense Battleship laid down 1916 (Engine 1931)

Displacement:
 27,390 t light; 28,602 t standard; 29,800 t normal; 30,759 t full load

Dimensions: Length overall / water x beam x draught
 650.00 ft / 650.00 ft x 118.00 ft x 27.00 ft (normal load)
 198.12 m / 198.12 m x 35.97 m  x 8.23 m

Armament:
      4 - 18.00" / 457 mm guns (2x2 guns), 2,916.00lbs / 1,322.68kg shells, 1916 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread
      16 - 4.00" / 102 mm guns (8x2 guns), 32.00lbs / 14.51kg shells, 1916 Model
   Quick firing guns in deck mounts with hoists
   on side, all amidships
 Weight of broadside 12,176 lbs / 5,523 kg
 Shells per gun, main battery: 90
 4 - 23.6" / 600.0001 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 10.0" / 254 mm 375.00 ft / 114.30 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 89 % of normal length

   - Torpedo Bulkhead:
  4.00" / 102 mm 375.00 ft / 114.30 m 26.00 ft / 7.92 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 10.0" / 254 mm 7.00" / 178 mm  10.0" / 254 mm
 2nd: 4.00" / 102 mm 4.00" / 102 mm  4.00" / 102 mm

   - Armour deck: 6.00" / 152 mm, Conning tower: 10.00" / 254 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 76,193 shp / 56,840 Kw = 26.00 kts
 Range 4,500nm at 15.00 kts
 Bunker at max displacement = 2,157 tons

Complement:
 1,133 - 1,474

Cost:
 £4.183 million / $16.731 million

Distribution of weights at normal displacement:
 Armament: 1,522 tons, 5.1 %
 Armour: 11,479 tons, 38.5 %
    - Belts: 2,732 tons, 9.2 %
    - Torpedo bulkhead: 1,443 tons, 4.8 %
    - Armament: 1,405 tons, 4.7 %
    - Armour Deck: 5,691 tons, 19.1 %
    - Conning Tower: 207 tons, 0.7 %
 Machinery: 2,278 tons, 7.6 %
 Hull, fittings & equipment: 12,111 tons, 40.6 %
 Fuel, ammunition & stores: 2,410 tons, 8.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   52,046 lbs / 23,607 Kg = 17.8 x 18.0 " / 457 mm shells or 11.2 torpedoes
 Stability (Unstable if below 1.00): 1.39
 Metacentric height 11.5 ft / 3.5 m
 Roll period: 14.6 seconds
 Steadiness - As gun platform (Average = 50 %): 54 %
   - Recoil effect (Restricted arc if above 1.00): 0.20
 Seaboat quality  (Average = 1.00): 1.09

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.504
 Length to Beam Ratio: 5.51 : 1
 'Natural speed' for length: 25.50 kts
 Power going to wave formation at top speed: 51 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 0.00 degrees
 Stern overhang: -1.00 ft / -0.30 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  22.00 ft / 6.71 m
    - Forecastle (20 %): 18.00 ft / 5.49 m
    - Mid (50 %):  18.00 ft / 5.49 m
    - Quarterdeck (15 %): 18.00 ft / 5.49 m
    - Stern:  18.00 ft / 5.49 m
    - Average freeboard: 18.32 ft / 5.58 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 76.5 %
  - Above water (accommodation/working, high = better): 148.1 %
 Waterplane Area: 51,274 Square feet or 4,763 Square metres
 Displacement factor (Displacement / loading): 106 %
 Structure weight / hull surface area: 189 lbs/sq ft or 923 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.46
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent

No comments:

Amazon Context Links