Kingdom costal defence ship.

Started by Korpen, March 31, 2009, 02:25:27 PM

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Korpen

While unlikely to be built, I find it an interesting study none the less.
Her shallow draft makes her usefull in all kinds of shallow and congested seas, such as the North Sea and around the Indonesian archipelago; it makes her less suited to high seas work however.
The 12cm belt and 25mm deck gives her adequate to very good protection against guns carried by ships of equal size as well as ships quite allot larger.
I would have preferred larger main guns, but that would have pushed size over 5000 ton. Still, combined with her firecontrol (250ton) it should be enough to give ships three times as large a run for their money. In fact just her 8x12cm gun secondary broadside is in fact greater then many similar sized ships got in for main battery.


Lombok, Netherlands CBB laid down 1916

Displacement:
   4 500 t light; 4 966 t standard; 5 272 t normal; 5 517 t full load

Dimensions: Length overall / water x beam x draught
   305,12 ft / 305,12 ft x 56,76 ft x 15,16 ft (normal load)
   93,00 m / 93,00 m x 17,30 m  x 4,62 m

Armament:
      4 - 12,01" / 305 mm guns (2x2 guns), 903,90lbs / 410,00kg shells, 1916 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread
      8 - 4,72" / 120 mm guns (4x2 guns), 52,91lbs / 24,00kg shells, 1916 Model
     Breech loading guns in deck mounts with hoists
     on side, all amidships
      4 - 4,72" / 120 mm guns (2x2 guns), 52,91lbs / 24,00kg shells, 1916 Model
     Breech loading guns in deck mounts with hoists
     on centreline ends, evenly spread, all raised mounts
   Weight of broadside 4 251 lbs / 1 928 kg
   Shells per gun, main battery: 148
   2 - 17,7" / 450 mm submerged torpedo tubes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   4,72" / 120 mm   193,57 ft / 59,00 m   9,84 ft / 3,00 m
   Ends:   Unarmoured
     Main Belt covers 98 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   7,87" / 200 mm   3,15" / 80 mm      6,69" / 170 mm
   2nd:   2,95" / 75 mm   0,98" / 25 mm      1,97" / 50 mm
   3rd:   2,95" / 75 mm   0,98" / 25 mm      1,97" / 50 mm

   - Armour deck: 0,98" / 25 mm, Conning tower: 7,87" / 200 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 4 000 shp / 2 984 Kw = 14,73 kts
   Range 4 100nm at 12,00 kts
   Bunker at max displacement = 551 tons

Complement:
   309 - 402

Cost:
   £0,996 million / $3,982 million

Distribution of weights at normal displacement:
   Armament: 512 tons, 9,7 %
   Armour: 1 156 tons, 21,9 %
      - Belts: 408 tons, 7,7 %
      - Torpedo bulkhead: 0 tons, 0,0 %
      - Armament: 443 tons, 8,4 %
      - Armour Deck: 253 tons, 4,8 %
      - Conning Tower: 51 tons, 1,0 %
   Machinery: 149 tons, 2,8 %
   Hull, fittings & equipment: 2 402 tons, 45,6 %
   Fuel, ammunition & stores: 772 tons, 14,6 %
   Miscellaneous weights: 281 tons, 5,3 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     5 676 lbs / 2 575 Kg = 6,6 x 12,0 " / 305 mm shells or 1,3 torpedoes
   Stability (Unstable if below 1.00): 1,15
   Metacentric height 2,8 ft / 0,9 m
   Roll period: 14,3 seconds
   Steadiness   - As gun platform (Average = 50 %): 57 %
         - Recoil effect (Restricted arc if above 1.00): 0,92
   Seaboat quality  (Average = 1.00): 1,50

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0,703
   Length to Beam Ratio: 5,38 : 1
   'Natural speed' for length: 17,47 kts
   Power going to wave formation at top speed: 45 %
   Trim (Max stability = 0, Max steadiness = 100): 38
   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:      16,40 ft / 5,00 m
      - Forecastle (20 %):   13,12 ft / 4,00 m
      - Mid (50 %):      11,48 ft / 3,50 m
      - Quarterdeck (15 %):   11,48 ft / 3,50 m
      - Stern:      13,12 ft / 4,00 m
      - Average freeboard:   12,44 ft / 3,79 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 94,1 %
      - Above water (accommodation/working, high = better): 101,8 %
   Waterplane Area: 13 917 Square feet or 1 293 Square metres
   Displacement factor (Displacement / loading): 90 %
   Structure weight / hull surface area: 129 lbs/sq ft or 632 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,90
      - Longitudinal: 2,34
      - 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

Card-carrying member of the Battlecruiser Fan Club.

miketr

neither fish nor fowl... its too slow to run away from anything, can't threaten the newest DN's, wait too small to take punishment.  Its slow speed makes it a sitting target for subs and torpedo boats.  As said while IMing I think some of the NPC's might like it or something like it.

Michael

Jefgte

#2
IMO, too slow.

If 5000t is your limit, Increase to 5000t for higher speed.
( test in 120m hull max...?...)

;)
"You French are fighting for money, while we English are fighting for honor!"
"Everyone is fighting for what they miss. "
Surcouf

Korpen

Quote from: Jefgte on March 31, 2009, 04:50:52 PM
IMO, too slow.
Not for a defensive ship. If the enemy run away from her, superb; mission accomplished and the thing she is defending is safe. If the enemy still press on they are likely to be several times stronger, and a ship such as this at least got the potential to strike outside her weight class. A hit or two from her main guns are likely to cause significant damage to a CL, making trying to swarm her a very risky proposition.   

Also bear in mind that in allot of areas were ships such as this operate larger ships are often incapable of going much faster if they want to avoid the sandbanks and rocks on the bottom anyway.

The ship is also cheap enough to have a degree of expendability, something usefull in close to shore operation with mines, reefs, rocks and costal defences. Risking anchoring a 20kton dreadnought in area were there is risk for attack is stupid, but the huge increase in accuracy might motivate doing so with a 4,5kton ship.


QuoteIf 5000t is your limit, Increase to 5000t for higher speed.
( test in 120m hull max...?...)
Increasing size by 11%, length by 10m and speed would result in a ship just 3kts faster, something that would not affect tactical function at all.
Card-carrying member of the Battlecruiser Fan Club.

Guinness

I'm with Korpen on this one. Sit her in a nice deep defensive minefield and in nice shallow water and she'd be a tough nut to crack, and could tie up the enemy for a good long time, hopefully until some nice fast Dutch frigates come along to help.

My main criticism is that I think she ought to be better protected, so she can take punishment longer.

Still, for high enough value targets, unsinkable heavy shore batteries might be a better buy for the money.