Swiss Minelayer

[Desertfox]

The Martin Luthers revisited, this time as minelayers. Mines have been succesful and the time has come for a dedicated minelayer. She carries 100 mines plus minesweeping equipment and a light wireless.


5 to be built:

Martin Luther
Jan Hus
John Wycliffe
William Tyndale
Huldrych Zwingli

Protestant class, New Switzerland Minelayer laid down 1908 (Engine 1909)

Displacement:
   745 t light; 821 t standard; 931 t normal; 1,020 t full load

Dimensions: Length overall / water x beam x draught
   270.00 ft / 270.00 ft x 27.00 ft x 10.40 ft (normal load)
   82.30 m / 82.30 m x 8.23 m  x 3.17 m

Armament:
      2 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1908 Model
     Breech loading guns in deck mounts
     on centreline ends, evenly spread
      4 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1908 Model
     Quick firing guns in deck mounts
     on side, all amidships
      4 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1908 Model
     Breech loading guns in deck mounts
     on side, evenly spread
   Weight of broadside 344 lbs / 156 kg
   Shells per gun, main battery: 270

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.00" / 25 mm         -               -

   - Armour deck: 1.00" / 25 mm, Conning tower: 2.00" / 51 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 8,144 shp / 6,075 Kw = 24.00 kts
   Range 5,100nm at 10.00 kts
   Bunker at max displacement = 200 tons

Complement:
   83 - 109

Cost:
   £0.102 million / $0.407 million

Distribution of weights at normal displacement:
   Armament: 43 tons, 4.6 %
   Armour: 96 tons, 10.3 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 7 tons, 0.8 %
      - Armour Deck: 85 tons, 9.1 %
      - Conning Tower: 4 tons, 0.4 %
   Machinery: 283 tons, 30.4 %
   Hull, fittings & equipment: 209 tons, 22.4 %
   Fuel, ammunition & stores: 186 tons, 20.0 %
   Miscellaneous weights: 115 tons, 12.3 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     302 lbs / 137 Kg = 2.8 x 6.0 " / 152 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.20
   Metacentric height 1.0 ft / 0.3 m
   Roll period: 11.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.56
   Seaboat quality  (Average = 1.00): 1.21

Hull form characteristics:
   Hull has low quarterdeck
   Block coefficient: 0.430
   Length to Beam Ratio: 10.00 : 1
   'Natural speed' for length: 16.43 kts
   Power going to wave formation at top speed: 58 %
   Trim (Max stability = 0, Max steadiness = 100): 58
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      15.00 ft / 4.57 m
      - Forecastle (25 %):   11.00 ft / 3.35 m
      - Mid (50 %):      10.00 ft / 3.05 m
      - Quarterdeck (25 %):   7.00 ft / 2.13 m (10.00 ft / 3.05 m before break)
      - Stern:      7.00 ft / 2.13 m
      - Average freeboard:   10.03 ft / 3.06 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 150.1 %
      - Above water (accommodation/working, high = better): 107.7 %
   Waterplane Area: 4,578 Square feet or 425 Square metres
   Displacement factor (Displacement / loading): 72 %
   Structure weight / hull surface area: 25 lbs/sq ft or 123 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.21
      - Overall: 0.55
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is adequate
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily




The rules are seriously skewed, my original design had slightly longer range, better seakeeping, and more misc weight but was twice the size. Using DD rules I cut down size in half.

For comparision:

Protestant class, New Switzerland Minelayer laid down 1908 (Engine 1909)

Displacement:
   1,520 t light; 1,613 t standard; 1,865 t normal; 2,067 t full load

Dimensions: Length overall / water x beam x draught
   310.00 ft / 310.00 ft x 32.00 ft x 14.00 ft (normal load)
   94.49 m / 94.49 m x 9.75 m  x 4.27 m

Armament:
      2 - 6.00" / 152 mm guns in single mounts, 105.00lbs / 47.63kg shells, 1908 Model
     Breech loading guns in deck mounts
     on centreline ends, evenly spread
      4 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1908 Model
     Quick firing guns in deck mounts
     on side, all amidships
      4 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1908 Model
     Breech loading guns in deck mounts
     on side, evenly spread
   Weight of broadside 338 lbs / 153 kg
   Shells per gun, main battery: 270
   4 - 18.0" / 457.2 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Ends:   Unarmoured
   Upper:   1.00" / 25 mm   100.00 ft / 30.48 m   5.00 ft / 1.52 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.00" / 25 mm         -               -

   - Armour deck: 1.00" / 25 mm, Conning tower: 2.00" / 51 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 12,115 shp / 9,038 Kw = 24.00 kts
   Range 7,700nm at 10.00 kts
   Bunker at max displacement = 454 tons

Complement:
   141 - 184

Cost:
   £0.166 million / $0.666 million

Distribution of weights at normal displacement:
   Armament: 43 tons, 2.3 %
   Armour: 157 tons, 8.4 %
      - Belts: 24 tons, 1.3 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 7 tons, 0.4 %
      - Armour Deck: 119 tons, 6.4 %
      - Conning Tower: 7 tons, 0.4 %
   Machinery: 551 tons, 29.5 %
   Hull, fittings & equipment: 596 tons, 32.0 %
   Fuel, ammunition & stores: 345 tons, 18.5 %
   Miscellaneous weights: 174 tons, 9.3 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1,408 lbs / 638 Kg = 13.0 x 6.0 " / 152 mm shells or 0.5 torpedoes
   Stability (Unstable if below 1.00): 1.20
   Metacentric height 1.3 ft / 0.4 m
   Roll period: 11.9 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.36
   Seaboat quality  (Average = 1.00): 1.57

Hull form characteristics:
   Hull has low quarterdeck
   Block coefficient: 0.470
   Length to Beam Ratio: 9.69 : 1
   'Natural speed' for length: 17.61 kts
   Power going to wave formation at top speed: 57 %
   Trim (Max stability = 0, Max steadiness = 100): 45
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      17.00 ft / 5.18 m
      - Forecastle (20 %):   14.00 ft / 4.27 m
      - Mid (50 %):      14.00 ft / 4.27 m
      - Quarterdeck (25 %):   10.00 ft / 3.05 m (14.00 ft / 4.27 m before break)
      - Stern:      10.00 ft / 3.05 m
      - Average freeboard:   13.24 ft / 4.04 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 125.2 %
      - Above water (accommodation/working, high = better): 96.9 %
   Waterplane Area: 6,435 Square feet or 598 Square metres
   Displacement factor (Displacement / loading): 105 %
   Structure weight / hull surface area: 47 lbs/sq ft or 227 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.80
      - Longitudinal: 2.62
      - Overall: 0.91
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is adequate
   Ship has slow, easy roll, a good, steady gun platform
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

[The Rock Doctor]

The armored deck on the larger design seems unnecessary - if she's facing gunfire, it's probably from destroyer or CL guns firing on flat-ish trajectories at close range in a night action.  Lose the deck and you can probably get the hull strength up to 1.00

[swamphen]

Also - while there were exceptions, I found an Italian CL or two - once you're going above 80% of your bunkerage as oil, the armoured-deck-only loses its attractiveness as the coal bunkerage doesn't provide side protection anymore.

(Yes, Seeadler is the same way - but it's one ship and somewhat experimental as a modification of the previous, mostly-coal, design.)