Mine Warfare ships

[Korpen]

The positional fighters.

[Korpen]

Space for more then 200 mines and a small radio set.
A candidate for "Ugliest ship in the navy". But the class is considered good for their purpose, to carry (protected from the elements) and lay large amounts of mines. A secondary function is to work as fast transports (of goods) for the fleet, as the sheltered mine hangar aft is capable of carrying almost a full ammunition load for an armoured frigate.

Prikkeldraad, The Netherlands Minelayer laid down 1906 (Engine 1905)
Friese ruiter
Gracht, Sunk during the war.
Fussangel

Displacement:
   1 250 t light; 1 283 t standard; 1 588 t normal; 1 832 t full load

Dimensions: Length overall / water x beam x draught
   295,28 ft / 295,28 ft x 39,37 ft x 9,84 ft (normal load)
   90,00 m / 90,00 m x 12,00 m  x 3,00 m

Armament:
      1 - 3,94" / 100 mm guns in single mounts, 37,48lbs / 17,00kg shells, 1906 Model
     Breech loading gun in deck mount
     on centreline forward
   Weight of broadside 37 lbs / 17 kg
   Shells per gun, main battery: 80

Machinery:
   Coal and oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 6 000 shp / 4 476 Kw = 20,32 kts
   Range 4 000nm at 12,00 kts
   Bunker at max displacement = 548 tons (90% coal)

Complement:
   125 - 163

Cost:
   £0,116 million / $0,465 million

Distribution of weights at normal displacement:
   Armament: 4 tons, 0,2 %
   Machinery: 495 tons, 31,2 %
   Hull, fittings & equipment: 531 tons, 33,4 %
   Fuel, ammunition & stores: 338 tons, 21,3 %
   Miscellaneous weights: 220 tons, 13,9 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1 663 lbs / 754 Kg = 54,5 x 3,9 " / 100 mm shells or 0,6 torpedoes
   Stability (Unstable if below 1.00): 1,41
   Metacentric height 2,3 ft / 0,7 m
   Roll period: 11,0 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0,01
   Seaboat quality  (Average = 1.00): 1,39

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0,486
   Length to Beam Ratio: 7,50 : 1
   'Natural speed' for length: 17,18 kts
   Power going to wave formation at top speed: 52 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   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:      19,69 ft / 6,00 m
      - Forecastle (20 %):   13,12 ft / 4,00 m
      - Mid (50 %):      9,84 ft / 3,00 m
      - Quarterdeck (15 %):   9,84 ft / 3,00 m
      - Stern:      9,84 ft / 3,00 m
      - Average freeboard:   11,52 ft / 3,51 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 118,1 %
      - Above water (accommodation/working, high = better): 123,5 %
   Waterplane Area: 7 647 Square feet or 710 Square metres
   Displacement factor (Displacement / loading): 128 %
   Structure weight / hull surface area: 48 lbs/sq ft or 232 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,96
      - Longitudinal: 1,48
      - Overall: 1,00
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is excellent
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

[Korpen]

Capacity for 30ton of minesweeping equipment, or mines, and has a small radioroom.
Built out of Teak and other woods. Machinery of civilian type to speed up construction.

24 vessels in service.

A-Class, Netherlands Minesweeper laid down 1908 (Engine 1909)

Displacement:
   200 t light; 207 t standard; 255 t normal; 293 t full load

Dimensions: Length overall / water x beam x draught
   149,62 ft / 146,98 ft x 21,00 ft x 4,59 ft (normal load)
   45,60 m / 44,80 m x 6,40 m  x 1,40 m

Armament:
      1 - 3,46" / 88,0 mm guns in single mounts, 19,84lbs / 9,00kg shells, 1908 Model
     Breech loading gun in deck mount
     on centreline forward, 1 raised gun
      2 - 1,97" / 50,0 mm guns in single mounts, 3,81lbs / 1,73kg shells, 1908 Model
     Breech loading guns in deck mounts
     on centreline, all aft, all raised mounts - superfiring
      2 - 0,31" / 8,0 mm guns in single mounts, 0,02lbs / 0,01kg shells, 1908 Model
     Breech loading guns in deck mounts
     on side, all amidships, all raised mounts - superfiring
   Weight of broadside 28 lbs / 12 kg
   Shells per gun, main battery: 120

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0,20" / 5 mm         -               -
   2nd:   0,20" / 5 mm         -               -
   3rd:   0,20" / 5 mm         -               -

Machinery:
   Coal fired boilers, complex reciprocating steam engines,
   Direct drive, 4 shafts, 829 ihp / 618 Kw = 15,00 kts
   Range 2 000nm at 12,00 kts  3200nm@10kts  5700nm@8kts
   Bunker at max displacement = 86 tons (100% coal)

Complement:
   31 - 41

Cost:
   £0,019 million / $0,076 million

Distribution of weights at normal displacement:
   Armament: 4 tons, 1,4 %
   Armour: 1 tons, 0,3 %
      - Belts: 0 tons, 0,0 %
      - Torpedo bulkhead: 0 tons, 0,0 %
      - Armament: 1 tons, 0,3 %
      - Armour Deck: 0 tons, 0,0 %
      - Conning Tower: 0 tons, 0,0 %
   Machinery: 64 tons, 25,0 %
   Hull, fittings & equipment: 92 tons, 36,2 %
   Fuel, ammunition & stores: 55 tons, 21,5 %
   Miscellaneous weights: 40 tons, 15,7 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     359 lbs / 163 Kg = 17,3 x 3,5 " / 88 mm shells or 0,3 torpedoes
   Stability (Unstable if below 1.00): 1,30
   Metacentric height 0,8 ft / 0,2 m
   Roll period: 10,1 seconds
   Steadiness   - As gun platform (Average = 50 %): 59 %
         - Recoil effect (Restricted arc if above 1.00): 0,12
   Seaboat quality  (Average = 1.00): 1,17

Hull form characteristics:
   Hull has rise forward of midbreak, low quarterdeck
   Block coefficient: 0,630
   Length to Beam Ratio: 7,00 : 1
   'Natural speed' for length: 12,12 kts
   Power going to wave formation at top speed: 57 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 15,00 degrees
   Stern overhang: 0,00 ft / 0,00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      9,84 ft / 3,00 m
      - Forecastle (20 %):   8,20 ft / 2,50 m
      - Mid (50 %):      7,55 ft / 2,30 m (7,22 ft / 2,20 m aft of break)
      - Quarterdeck (10 %):   3,28 ft / 1,00 m (7,22 ft / 2,20 m before break)
      - Stern:      3,28 ft / 1,00 m
      - Average freeboard:   7,35 ft / 2,24 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 109,0 %
      - Above water (accommodation/working, high = better): 106,9 %
   Waterplane Area: 2 320 Square feet or 216 Square metres
   Displacement factor (Displacement / loading): 130 %
   Structure weight / hull surface area: 27 lbs/sq ft or 131 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,92
      - Longitudinal: 2,13
      - Overall: 1,00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is adequate

[Korpen]

Enlarged A-class sweeper. Also built out of wood.


BM1, The Kingdom B-Class laid down 1910 (Engine 1909)
10 ships in service

Displacement:
   400 t light; 415 t standard; 576 t normal; 706 t full load

Dimensions: Length overall / water x beam x draught
   168,96 ft / 167,32 ft x 30,12 ft x 6,56 ft (normal load)
   51,50 m / 51,00 m x 9,18 m  x 2,00 m

Armament:
      1 - 3,46" / 88,0 mm guns in single mounts, 19,84lbs / 9,00kg shells, 1910 Model
     Quick firing gun in deck mount
     on centreline forward
      2 - 1,97" / 50,0 mm guns in single mounts, 3,81lbs / 1,73kg shells, 1910 Model
     Quick firing guns in deck mounts
     on side, all forward
      4 - 0,59" / 15,0 mm guns in single mounts, 0,10lbs / 0,05kg shells, 1910 Model
     Machine guns in deck mounts
     on side, all forward, all raised mounts - superfiring
   Weight of broadside 28 lbs / 13 kg
   Shells per gun, main battery: 150

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0,39" / 10 mm         -               -
   2nd:   0,39" / 10 mm         -               -
   3rd:   0,39" / 10 mm         -               -

Machinery:
   Oil fired boilers, complex reciprocating steam engines,
   Direct drive, 2 shafts, 1 300 ihp / 969 Kw = 14,92 kts
   Range 6 000nm at 12,00 kts
   Bunker at max displacement = 291 tons

Complement:
   58 - 76

Cost:
   £0,030 million / $0,119 million

Distribution of weights at normal displacement:
   Armament: 4 tons, 0,6 %
   Armour: 2 tons, 0,3 %
      - Belts: 0 tons, 0,0 %
      - Torpedo bulkhead: 0 tons, 0,0 %
      - Armament: 2 tons, 0,3 %
      - Armour Deck: 0 tons, 0,0 %
      - Conning Tower: 0 tons, 0,0 %
   Machinery: 91 tons, 15,8 %
   Hull, fittings & equipment: 224 tons, 38,9 %
   Fuel, ammunition & stores: 176 tons, 30,5 %
   Miscellaneous weights: 80 tons, 13,9 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1 589 lbs / 721 Kg = 76,4 x 3,5 " / 88 mm shells or 0,8 torpedoes
   Stability (Unstable if below 1.00): 1,33
   Metacentric height 1,4 ft / 0,4 m
   Roll period: 10,8 seconds
   Steadiness   - As gun platform (Average = 50 %): 66 %
         - Recoil effect (Restricted arc if above 1.00): 0,04
   Seaboat quality  (Average = 1.00): 2,00

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0,610
   Length to Beam Ratio: 5,56 : 1
   'Natural speed' for length: 12,94 kts
   Power going to wave formation at top speed: 57 %
   Trim (Max stability = 0, Max steadiness = 100): 33
   Bow angle (Positive = bow angles forward): 0,00 degrees
   Stern overhang: 1,64 ft / 0,50 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      19,69 ft / 6,00 m
      - Forecastle (20 %):   16,40 ft / 5,00 m
      - Mid (60 %):      16,40 ft / 5,00 m (8,20 ft / 2,50 m aft of break)
      - Quarterdeck (15 %):   8,20 ft / 2,50 m
      - Stern:      8,20 ft / 2,50 m
      - Average freeboard:   13,39 ft / 4,08 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 72,0 %
      - Above water (accommodation/working, high = better): 161,9 %
   Waterplane Area: 3 720 Square feet or 346 Square metres
   Displacement factor (Displacement / loading): 197 %
   Structure weight / hull surface area: 34 lbs/sq ft or 168 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,80
      - Longitudinal: 7,04
      - Overall: 1,00
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is excellent
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

[Korpen]

Class of initially twelve boats, first dedicated sweepers built for European service. Armed and equipped to be able to function as a costal and North Sea escort in addition to its primary function of mine laying and sweeping.
Some of the ships will be stationed with the submarine school in peace time, were they can assist in training engine room crews (one of the reason for diesel engines), torpedo recovery and as accommodation ship (considering that the O2-subs only have a crew of ten, there is space enough for that).

Top speed is estimated to 17,5kts, as the central shafts placement gives it a highly inefficient water flow at top speed with all three props running. Cruising speed is set to the ideal effect of a single engine. So under longer cruises the ship is usually only having one engine running, and the others undergoing maintenance.   


Zeeland (34-class), Netherlands Minesweeper laid down 1911 (Engine 1909)

24 ships in class

Displacement:
   340 t light; 353 t standard; 460 t normal; 545 t full load

Dimensions: Length overall / water x beam x draught
   182,76 ft / 178,81 ft x 24,93 ft x 6,56 ft (normal load)
   55,71 m / 54,50 m x 7,60 m  x 2,00 m

Armament:
      1 - 3,94" / 100 mm guns in single mounts, 37,48lbs / 17,00kg shells, 1911 Model
     Quick firing gun in deck mount
     on centreline forward
      2 - 1,97" / 50,0 mm guns in single mounts, 3,81lbs / 1,73kg shells, 1911 Model
     Breech loading guns in deck mounts
     on side, all aft
      2 - 0,31" / 8,0 mm guns in single mounts, 0,02lbs / 0,01kg shells, 1911 Model
     Breech loading guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 45 lbs / 20 kg
   Shells per gun, main battery: 151

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0,59" / 15 mm         -               -
   2nd:   0,39" / 10 mm         -               -
   3rd:   0,39" / 10 mm         -               -

   - Conning tower: 1,57" / 40 mm

Machinery:
   Diesel Internal combustion motors,
   Direct drive, 3 shafts, 2 250 shp / 1 679 Kw = 18,13 kts
   Range 3 793nm at 12,98 kts
   Bunker at max displacement = 192 tons

Complement:
   49 - 64

Cost:
   £0,030 million / $0,121 million

Distribution of weights at normal displacement:
   Armament: 5 tons, 1,0 %
   Armour: 4 tons, 0,9 %
      - Belts: 0 tons, 0,0 %
      - Torpedo bulkhead: 0 tons, 0,0 %
      - Armament: 2 tons, 0,4 %
      - Armour Deck: 0 tons, 0,0 %
      - Conning Tower: 2 tons, 0,4 %
   Machinery: 102 tons, 22,2 %
   Hull, fittings & equipment: 160 tons, 34,9 %
   Fuel, ammunition & stores: 120 tons, 26,1 %
   Miscellaneous weights: 68 tons, 14,8 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     703 lbs / 319 Kg = 23,0 x 3,9 " / 100 mm shells or 0,5 torpedoes
   Stability (Unstable if below 1.00): 1,25
   Metacentric height 0,9 ft / 0,3 m
   Roll period: 10,8 seconds
   Steadiness   - As gun platform (Average = 50 %): 61 %
         - Recoil effect (Restricted arc if above 1.00): 0,09
   Seaboat quality  (Average = 1.00): 1,22

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0,550
   Length to Beam Ratio: 7,17 : 1
   'Natural speed' for length: 13,37 kts
   Power going to wave formation at top speed: 61 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 15,00 degrees
   Stern overhang: 0,00 ft / 0,00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      14,76 ft / 4,50 m
      - Forecastle (20 %):   13,12 ft / 4,00 m
      - Mid (40 %):      13,12 ft / 4,00 m (6,56 ft / 2,00 m aft of break)
      - Quarterdeck (15 %):   6,56 ft / 2,00 m
      - Stern:      6,56 ft / 2,00 m
      - Average freeboard:   9,32 ft / 2,84 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 96,9 %
      - Above water (accommodation/working, high = better): 103,8 %
   Waterplane Area: 3 111 Square feet or 289 Square metres
   Displacement factor (Displacement / loading): 146 %
   Structure weight / hull surface area: 32 lbs/sq ft or 155 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,89
      - Longitudinal: 2,68
      - Overall: 1,00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is adequate
   Good seaboat, rides out heavy weather easily

The ships dimension and general capabillity is based on the IRL Arhomla-class sweepers.