Belted or protected - which better?

[Borys]

Ahoj!
I'm thinking of building a couple of Flotilla Leaders for the Meditteranean.
I'm not sure whethr to go with a belted design, or a classical protected layout.

Gun arangment is "clasical German", i.e. pairs on sides, the fore and aft pair crossdecking. TT are twins  on each side.

Belted version:
SMS Schneeblitz, Austria Klein kreuzer laid down 1911 (Engine 1909)

Displacement:
   1 972 t light; 2 043 t standard; 2 268 t normal; 2 448 t full load

Dimensions: Length overall / water x beam x draught
   360,00 ft / 360,00 ft x 37,50 ft x 14,00 ft (normal load)
   109,73 m / 109,73 m x 11,43 m  x 4,27 m

Armament:
      6 - 4,00" / 102 mm guns in single mounts, 35,00lbs / 15,88kg shells, 1911 Model
     Quick firing guns in deck mounts with hoists
     on side, evenly spread, 2 raised mounts
      4 - 0,43" / 11,0 mm guns in single mounts, 0,04lbs / 0,02kg shells, 1911 Model
     Machine guns in deck mounts
     on side, all amidships
      2 - 0,43" / 11,0 mm guns in single mounts, 0,04lbs / 0,02kg shells, 1911 Model
     Machine guns in deck mounts
     on side, evenly spread
   Weight of broadside 210 lbs / 95 kg
   Shells per gun, main battery: 220
   4 - 18,0" / 457,2 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   1,30" / 33 mm   310,00 ft / 94,49 m   12,00 ft / 3,66 m
   Ends:   Unarmoured
     Main Belt covers 132% of normal length

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 18 700 shp / 13 950 Kw = 26,50 kts
   Range 4 000nm at 12,00 kts
   Bunker at max displacement = 405 tons

Complement:
   163 - 213

Cost:
   £0,208 million / $0,833 million

Distribution of weights at normal displacement:
   Armament: 24 tons, 1,1%
   Armour: 192 tons, 8,5%
      - Belts: 192 tons, 8,5%
      - Torpedo bulkhead: 0 tons, 0,0%
      - Armament: 0 tons, 0,0%
      - Armour Deck: 0 tons, 0,0%
      - Conning Tower: 0 tons, 0,0%
   Machinery: 850 tons, 37,5%
   Hull, fittings & equipment: 878 tons, 38,7%
   Fuel, ammunition & stores: 296 tons, 13,1%
   Miscellaneous weights: 28 tons, 1,2%

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1 815 lbs / 823 Kg = 56,7 x 4,0 " / 102 mm shells or 0,6 torpedoes
   Stability (Unstable if below 1.00): 1,32
   Metacentric height 1,9 ft / 0,6 m
   Roll period: 11,5 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0,25
   Seaboat quality  (Average = 1.00): 1,37

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0,420
   Length to Beam Ratio: 9,60 : 1
   'Natural speed' for length: 18,97 kts
   Power going to wave formation at top speed: 56 %
   Trim (Max stability = 0, Max steadiness = 100): 52
   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:      20,87 ft / 6,36 m
      - Forecastle (20%):   13,28 ft / 4,05 m
      - Mid (50%):      13,28 ft / 4,05 m
      - Quarterdeck (15%):   13,28 ft / 4,05 m
      - Stern:      13,28 ft / 4,05 m
      - Average freeboard:   13,89 ft / 4,23 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 131,5%
      - Above water (accommodation/working, high = better): 111,0%
   Waterplane Area: 8 416 Square feet or 782 Square metres
   Displacement factor (Displacement / loading): 107%
   Structure weight / hull surface area: 58 lbs/sq ft or 284 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,92
      - Longitudinal: 2,13
      - Overall: 1,00
   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

[Borys]

Protected:
SMS Schneeblitz, Austria Klein kreuzer laid down 1911 (Engine 1909)

Displacement:
   1 983 t light; 2 054 t standard; 2 280 t normal; 2 461 t full load

Dimensions: Length overall / water x beam x draught
   360,00 ft / 360,00 ft x 37,70 ft x 14,00 ft (normal load)
   109,73 m / 109,73 m x 11,49 m  x 4,27 m

Armament:
      6 - 4,00" / 102 mm guns in single mounts, 35,00lbs / 15,88kg shells, 1911 Model
     Quick firing guns in deck mounts with hoists
     on side, evenly spread, 2 raised mounts
      4 - 0,43" / 11,0 mm guns in single mounts, 0,04lbs / 0,02kg shells, 1911 Model
     Machine guns in deck mounts
     on side, all amidships
      2 - 0,43" / 11,0 mm guns in single mounts, 0,04lbs / 0,02kg shells, 1911 Model
     Machine guns in deck mounts
     on side, evenly spread
   Weight of broadside 210 lbs / 95 kg
   Shells per gun, main battery: 220
   4 - 18,0" / 457,2 mm above water torpedoes

Armour:

   - Armour deck: 1,25" / 32 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 18 773 shp / 14 005 Kw = 26,50 kts
   Range 4 000nm at 12,00 kts
   Bunker at max displacement = 406 tons

Complement:
   164 - 214

Cost:
   £0,209 million / $0,836 million

Distribution of weights at normal displacement:
   Armament: 24 tons, 1,1%
   Armour: 196 tons, 8,6%
      - Belts: 0 tons, 0,0%
      - Torpedo bulkhead: 0 tons, 0,0%
      - Armament: 0 tons, 0,0%
      - Armour Deck: 196 tons, 8,6%
      - Conning Tower: 0 tons, 0,0%
   Machinery: 853 tons, 37,4%
   Hull, fittings & equipment: 882 tons, 38,7%
   Fuel, ammunition & stores: 297 tons, 13,0%
   Miscellaneous weights: 28 tons, 1,2%

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1 833 lbs / 831 Kg = 57,3 x 4,0 " / 102 mm shells or 0,6 torpedoes
   Stability (Unstable if below 1.00): 1,32
   Metacentric height 1,9 ft / 0,6 m
   Roll period: 11,5 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0,24
   Seaboat quality  (Average = 1.00): 1,36

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0,420
   Length to Beam Ratio: 9,55 : 1
   'Natural speed' for length: 18,97 kts
   Power going to wave formation at top speed: 56 %
   Trim (Max stability = 0, Max steadiness = 100): 52
   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:      20,87 ft / 6,36 m
      - Forecastle (20%):   13,28 ft / 4,05 m
      - Mid (50%):      13,28 ft / 4,05 m
      - Quarterdeck (15%):   13,28 ft / 4,05 m
      - Stern:      13,28 ft / 4,05 m
      - Average freeboard:   13,89 ft / 4,23 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 131,3%
      - Above water (accommodation/working, high = better): 111,0%
   Waterplane Area: 8 461 Square feet or 786 Square metres
   Displacement factor (Displacement / loading): 107%
   Structure weight / hull surface area: 58 lbs/sq ft or 286 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,92
      - Longitudinal: 2,11
      - Overall: 1,00
   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

[P3D]

As your belted cruiser has not even splinter protection over magazines/machinery, it has only marginally longer life expectancy than the Swiss flotilla leaders. The protected deck, however, is less effective after getting rid of the extra protection provided by the coal bunkers.

[Sachmle]

If you're gonna go w/ any armor at all then you should uses enough to matter. 33mm is not gonna stop much, the protected actually has better survivability.  For 11t of displacement you get 18t of survivability. Until your coal bunkers get too low, you're better off w/ the protected deck version, but if you could but 2" plate on the other, or thicker, you're probably better off in the end.

[Borys]

Ahoj!
Problem is that I have NO coal bunkers :)
Well, it seems that there are limits of what one can achieve on 2000 tonnes.
Maybe I will just build four or six repeat Ulans.
Actually, I reworked the Ulan a bit ...
Borys


Austria Klein kreuzer laid down 1911 (Engine 1909)

Displacement:
   2 494 t light; 2 580 t standard; 2 797 t normal; 2 971 t full load

Dimensions: Length overall / water x beam x draught
   360,89 ft / 360,89 ft x 39,37 ft x 16,40 ft (normal load)
   110,00 m / 110,00 m x 12,00 m  x 5,00 m

Armament:
      7 - 4,00" / 102 mm guns in single mounts, 35,00lbs / 15,88kg shells, 1911 Model
     Breech loading guns in deck mounts with hoists
     on side, evenly spread, 2 raised mounts
      4 - 0,43" / 11,0 mm guns (2x2 guns), 0,04lbs / 0,02kg shells, 1911 Model
     Machine guns in deck mounts
     on side, evenly spread
   Weight of broadside 245 lbs / 111 kg
   Shells per gun, main battery: 220
   4 - 18,0" / 457,2 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   2,00" / 51 mm   310,00 ft / 94,49 m   10,50 ft / 3,20 m
   Ends:   Unarmoured
     Main Belt covers 132% of normal length

   - Armour deck: 1,00" / 25 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 23 161 shp / 17 278 Kw = 27,00 kts
   Range 5 000nm at 10,00 kts
   Bunker at max displacement = 391 tons

Complement:
   191 - 249

Cost:
   £0,258 million / $1,033 million

Distribution of weights at normal displacement:
   Armament: 28 tons, 1,0%
   Armour: 423 tons, 15,1%
      - Belts: 259 tons, 9,3%
      - Torpedo bulkhead: 0 tons, 0,0%
      - Armament: 0 tons, 0,0%
      - Armour Deck: 164 tons, 5,9%
      - Conning Tower: 0 tons, 0,0%
   Machinery: 1 053 tons, 37,6%
   Hull, fittings & equipment: 960 tons, 34,3%
   Fuel, ammunition & stores: 303 tons, 10,8%
   Miscellaneous weights: 30 tons, 1,1%

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1 906 lbs / 864 Kg = 59,6 x 4,0 " / 102 mm shells or 0,6 torpedoes
   Stability (Unstable if below 1.00): 1,27
   Metacentric height 1,9 ft / 0,6 m
   Roll period: 12,0 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0,21
   Seaboat quality  (Average = 1.00): 1,23

Hull form characteristics:
   Hull has raised forecastle
   Block coefficient: 0,420
   Length to Beam Ratio: 9,17 : 1
   'Natural speed' for length: 19,00 kts
   Power going to wave formation at top speed: 58 %
   Trim (Max stability = 0, Max steadiness = 100): 57
   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:      22,00 ft / 6,71 m
      - Forecastle (25%):   19,00 ft / 5,79 m (12,00 ft / 3,66 m aft of break)
      - Mid (50%):      12,00 ft / 3,66 m
      - Quarterdeck (15%):   12,00 ft / 3,66 m
      - Stern:      12,00 ft / 3,66 m
      - Average freeboard:   14,05 ft / 4,28 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 131,4%
      - Above water (accommodation/working, high = better): 90,9%
   Waterplane Area: 8 858 Square feet or 823 Square metres
   Displacement factor (Displacement / loading): 101%
   Structure weight / hull surface area: 60 lbs/sq ft or 294 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,92
      - Longitudinal: 2,15
      - Overall: 1,00
   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

[Ithekro]

In "Fire When Ready" protected cruisers tend to get pounded and will take lots of criticals as they have little to no armor to stop most of the shells.   In more advanced systems that deal with "over penetration" protected cruiser's lack of armor can be your friend.  Most shells will tend to pass through and due minimal damage for each one as the shell's explosives are not set off.  However if the enemy is smart and switches to High Explosives that do not have high armor penetration, they will probably still explode inside the ship, and thus end your cruiser's career. 

We've had 1910 light cruiser engagements were the thing that killed the German light cruisers against America light cruisers was the slightly heavier armor on the conning tower and the guns.  Those were just thick enough to set off the American shells and wrecked the German ships.

[P3D]

I'd get at a pair of 6"s on the Ulans.

[Borys]

Ahoj!
I think CAP is the most common shell - I think.
Yes, APC will (should) fly through those cruisers, while CAP/HE will go bang.

Ulans with 6 inchers - is the below design better, and why?
Maybe - GASP - I should import 5 inch guns? Or develop a 4,5" 50 pounder?

Austria Klein kreuzer laid down 1911 (Engine 1909)

Displacement:
   2 486 t light; 2 588 t standard; 2 763 t normal; 2 903 t full load

Dimensions: Length overall / water x beam x draught
   360,00 ft / 360,00 ft x 39,00 ft x 16,40 ft (normal load)
   109,73 m / 109,73 m x 11,89 m  x 5,00 m

Armament:
      2 - 6,00" / 152 mm guns in single mounts, 100,00lbs / 45,36kg shells, 1911 Model
     Breech loading guns in deck mounts with hoists
     on side, evenly spread, 1 raised mount
      4 - 4,00" / 102 mm guns in single mounts, 35,00lbs / 15,88kg shells, 1911 Model
     Quick firing guns in deck mounts
     on side, all amidships
      4 - 0,43" / 11,0 mm guns (2x2 guns), 0,04lbs / 0,02kg shells, 1911 Model
     Machine guns in deck mounts
     on side, evenly spread
   Weight of broadside 340 lbs / 154 kg
   Shells per gun, main battery: 220
   4 - 18,0" / 457,2 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   2,00" / 51 mm   310,00 ft / 94,49 m   10,50 ft / 3,20 m
   Ends:   Unarmoured
     Main Belt covers 132% of normal length
     Main belt does not fully cover magazines and engineering spaces

   - Armour deck: 1,00" / 25 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 22 995 shp / 17 154 Kw = 27,00 kts
   Range 4 000nm at 10,00 kts
   Bunker at max displacement = 316 tons

Complement:
   189 - 247

Cost:
   £0,267 million / $1,067 million

Distribution of weights at normal displacement:
   Armament: 43 tons, 1,6%
   Armour: 421 tons, 15,2%
      - Belts: 259 tons, 9,4%
      - Torpedo bulkhead: 0 tons, 0,0%
      - Armament: 0 tons, 0,0%
      - Armour Deck: 162 tons, 5,9%
      - Conning Tower: 0 tons, 0,0%
   Machinery: 1 025 tons, 37,1%
   Hull, fittings & equipment: 967 tons, 35,0%
   Fuel, ammunition & stores: 277 tons, 10,0%
   Miscellaneous weights: 30 tons, 1,1%

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1 799 lbs / 816 Kg = 16,7 x 6,0 " / 152 mm shells or 0,6 torpedoes
   Stability (Unstable if below 1.00): 1,26
   Metacentric height 1,8 ft / 0,6 m
   Roll period: 12,0 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0,26
   Seaboat quality  (Average = 1.00): 1,25

Hull form characteristics:
   Hull has raised forecastle
   Block coefficient: 0,420
   Length to Beam Ratio: 9,23 : 1
   'Natural speed' for length: 18,97 kts
   Power going to wave formation at top speed: 58 %
   Trim (Max stability = 0, Max steadiness = 100): 56
   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:      22,00 ft / 6,71 m
      - Forecastle (26%):   19,00 ft / 5,79 m (12,00 ft / 3,66 m aft of break)
      - Mid (50%):      12,00 ft / 3,66 m
      - Quarterdeck (15%):   12,00 ft / 3,66 m
      - Stern:      12,00 ft / 3,66 m
      - Average freeboard:   14,13 ft / 4,31 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 134,1%
      - Above water (accommodation/working, high = better): 90,6%
   Waterplane Area: 8 753 Square feet or 813 Square metres
   Displacement factor (Displacement / loading): 96%
   Structure weight / hull surface area: 61 lbs/sq ft or 296 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,91
      - Longitudinal: 2,24
      - Overall: 1,00
   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

[P3D]

Overall WWI experience showed that 6" is much more effective. The Austrians Rapidkreuzers, while fast, were undergunned in WWI. Against cruisers that can stand up to damage you need something with punch. I'd suggest 2x6"+6x4".

The range is unacceptable for an Austrian cruiser, especially with oil firing. Helgoland has 1600@24 radius and a 700t bunker. While long range itself is not important, Austrian ships supposed to operate at high speeds during war - the limited theater of the Adriatic allowed for that. I noted at other places, that Austrian destroyers had the requirement to sail from Cattaro to the Straits of Otranto and back - on full power (27-32kts).

[Borys]

Ahoj!
So, the 2x6" and 4x4" design is OK?

This is a different world - the KuKK is not limited to the Adriatic. Austrian ships are no logner 440 yard runners - they are the milers, with a burts of speed when needed.

With those 174 tonnes of oil the ship can run 450 nm at 24 knots.

Borys

[Ithekro]

Won't that depend on who is trying to suppress your fleet during a time of war?

[Borys]

There also is the issue of the ships these cruisers are to lead ... look at the Gtb 1909 aka the H6.
Borys