Torpedo Cruiser

[Carthaginian]

I'm thinking about using these as patrol cruisers. She's small, and lightly armed when you first look at her- and then you see a whole mess of torpedo wakes coming at you.

My question is, would it be something that could actually be built? Would that number of tubes fit into this small hull? Is it's speed sufficient to keep it out of danger?


CSA Torpedo Cruiser proposal #1

Displacement:
   2,000 t light; 2,079 t standard; 2,310 t normal; 2,495 t full load

Dimensions: Length overall / water x beam x draught
   350.00 ft / 350.00 ft x 35.00 ft x 15.50 ft (normal load)
   106.68 m / 106.68 m x 10.67 m  x 4.72 m

Armament:
      3 - 4.50" / 114 mm guns in single mounts, 50.00lbs / 22.68kg shells, 1907 Model
     Quick firing guns in deck mounts with hoists
     on centreline, evenly spread, 1 raised mount
     Aft Main mounts separated by engine room
      4 - 4.50" / 114 mm guns in single mounts, 50.00lbs / 22.68kg shells, 1907 Model
     Quick firing guns in deck mounts with hoists
     on side ends, evenly spread
   Weight of broadside 350 lbs / 159 kg
   Shells per gun, main battery: 150
   7 - 19.5" / 495.3 mm submerged torpedo tubes

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.00" / 25 mm         -         1.00" / 25 mm
   2nd:   1.00" / 25 mm         -         1.00" / 25 mm

   - Armour deck: 2.30" / 58 mm, Conning tower: 2.10" / 53 mm

Machinery:
   Oil fired boilers, steam turbines,
   No drive to shaft, 2 shafts, 15,170 shp / 11,317 Kw = 25.00 kts
   Range 6,000nm at 10.00 kts
   Bunker at max displacement = 416 tons

Complement:
   166 - 216

Cost:
   £0.200 million / $0.800 million

Distribution of weights at normal displacement:
   Armament: 40 tons, 1.7 %
   Armour: 352 tons, 15.3 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 18 tons, 0.8 %
      - Armour Deck: 326 tons, 14.1 %
      - Conning Tower: 8 tons, 0.3 %
   Machinery: 690 tons, 29.9 %
   Hull, fittings & equipment: 887 tons, 38.4 %
   Fuel, ammunition & stores: 310 tons, 13.4 %
   Miscellaneous weights: 31 tons, 1.3 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1,357 lbs / 616 Kg = 29.8 x 4.5 " / 114 mm shells or 0.5 torpedoes
   Stability (Unstable if below 1.00): 1.21
   Metacentric height 1.5 ft / 0.4 m
   Roll period: 12.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.50
   Seaboat quality  (Average = 1.00): 1.53

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.426
   Length to Beam Ratio: 10.00 : 1
   'Natural speed' for length: 18.71 kts
   Power going to wave formation at top speed: 53 %
   Trim (Max stability = 0, Max steadiness = 100): 46
   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:      21.00 ft / 6.40 m
      - Forecastle (20 %):   13.00 ft / 3.96 m
      - Mid (50 %):      13.00 ft / 3.96 m
      - Quarterdeck (15 %):   13.00 ft / 3.96 m
      - Stern:      13.00 ft / 3.96 m
      - Average freeboard:   13.64 ft / 4.16 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 144.2 %
      - Above water (accommodation/working, high = better): 114.4 %
   Waterplane Area: 7,669 Square feet or 712 Square metres
   Displacement factor (Displacement / loading): 111 %
   Structure weight / hull surface area: 60 lbs/sq ft or 292 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.90
      - Longitudinal: 2.45
      - 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
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

7 submerged torpedo tubes:
1 forward
3 starboard beam
3 port beam

[P3D]

- no drive to shaft
- hull below water is a bit extreme 144%
- block coefficient way too low

How many torpedo reloads it is carrying?

[Carthaginian]

- no drive to shaft

That's no problem... won't change anything.

- hull below water is a bit extreme 144%
- block coefficient way too low

I can try and get it down, but it's cramped, I'll have to remove a pair of broadside tubes. I only have one site I can go to to find BC's for ships, and it's not up right now. What would be a 'proper' BC for a small, fast ship. This isn't so much a cruiser as it is a 'super-sized' torpedo boat. A destroyer-like BC wouldn't be out of the ordinary, I would think.

How many torpedo reloads it is carrying?

3 per tube, for 21 torps total.

[Desertfox]

Not enough torpedoes. My own cruisers have a broadsied of 4 torpedoes. You could get a license from NS, my own ships have more tubes, more speed, and more guns.

[P3D]

The problem is that you have to cram your torpedoes into a very limited underwater volume in addition to the engines and magazines. The broadside TTs also have to be at an angle to the sides otherwise they won't fit into the beam - and with the fine (low BC hull) you would have even less beam where the torpedo room(s) would be located.

I like the idea of keeping the TTs protected underwater, but SS is unfortunately not detailed for such a design.

[Carthaginian]

Not enough torpedoes. My own cruisers have a broadsied of 4 torpedoes. You could get a license from NS, my own ships have more tubes, more speed, and more guns.

The offer from NS is appreciated, but the CSN is requiring this design be home-built in order to gain more experience for it's shipwrights.

OoC Translation - I gotta get more practice building ships in.
I don't really know what I'm doing quite yet.

[Carthaginian]

The problem is that you have to cram your torpedoes into a very limited underwater volume in addition to the engines and magazines. The broadside TTs also have to be at an angle to the sides otherwise they won't fit into the beam - and with the fine (low BC hull) you would have even less beam where the torpedo room(s) would be located.

I like the idea of keeping the TTs protected underwater, but SS is unfortunately not detailed for such a design.

Advice I'll listen to.
I'll make her a bit 'fatter' and try again.
The CSA is not going to mount above water torps unless absolutely necessary, so if there are torpedo tubes on our larger ships, they will continue to be submerged.

[Carthaginian]

OK, this one's a bit heavier, and the BC is almost .500.
It's little faster too, at 26 knots instead of 25 knots.
All tubes are moved to the broadsides, in a fashion similar to a modern nuke submarine's torpedo layout. The 4.5" guns get a strange layout, with three forward in a triangle layout and four aft, two on either beam.


CSA Torpedo Cruiser proposal #2

Displacement:
   2,500 t light; 2,595 t standard; 2,986 t normal; 3,299 t full load

Dimensions: Length overall / water x beam x draught
   380.00 ft / 380.00 ft x 40.00 ft x 14.00 ft (normal load)
   115.82 m / 115.82 m x 12.19 m  x 4.27 m

Armament:
      1 - 4.50" / 114 mm guns in single mounts, 50.00lbs / 22.68kg shells, 1907 Model
     Quick firing gun in a deck mount with hoist
     on centreline forward
      2 - 4.50" / 114 mm guns in single mounts, 50.00lbs / 22.68kg shells, 1907 Model
     Quick firing guns in deck mounts with hoists
     on side, all forward
      4 - 4.50" / 114 mm guns in single mounts, 50.00lbs / 22.68kg shells, 1907 Model
     Quick firing guns in deck mounts with hoists
     on side, all aft
   Weight of broadside 350 lbs / 159 kg
   Shells per gun, main battery: 150
   8 - 19.5" / 495.3 mm submerged torpedo tubes

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.00" / 25 mm         -         1.00" / 25 mm
   2nd:   1.00" / 25 mm         -         1.00" / 25 mm
   3rd:   1.00" / 25 mm         -         1.00" / 25 mm

   - Armour deck: 2.30" / 58 mm, Conning tower: 2.10" / 53 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 20,795 shp / 15,513 Kw = 26.00 kts
   Range 6,000nm at 12.00 kts
   Bunker at max displacement = 704 tons

Complement:
   201 - 262

Cost:
   £0.253 million / $1.013 million

Distribution of weights at normal displacement:
   Armament: 40 tons, 1.3 %
   Armour: 455 tons, 15.2 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 18 tons, 0.6 %
      - Armour Deck: 427 tons, 14.3 %
      - Conning Tower: 9 tons, 0.3 %
   Machinery: 945 tons, 31.7 %
   Hull, fittings & equipment: 1,026 tons, 34.4 %
   Fuel, ammunition & stores: 486 tons, 16.3 %
   Miscellaneous weights: 34 tons, 1.1 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1,722 lbs / 781 Kg = 37.8 x 4.5 " / 114 mm shells or 0.5 torpedoes
   Stability (Unstable if below 1.00): 1.24
   Metacentric height 1.9 ft / 0.6 m
   Roll period: 12.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.27
   Seaboat quality  (Average = 1.00): 1.05

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.491
   Length to Beam Ratio: 9.50 : 1
   'Natural speed' for length: 19.49 kts
   Power going to wave formation at top speed: 56 %
   Trim (Max stability = 0, Max steadiness = 100): 66
   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:      20.00 ft / 6.10 m
      - Forecastle (20 %):   12.00 ft / 3.66 m
      - 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:   12.64 ft / 3.85 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 144.3 %
      - Above water (accommodation/working, high = better): 114.2 %
   Waterplane Area: 10,046 Square feet or 933 Square metres
   Displacement factor (Displacement / loading): 111 %
   Structure weight / hull surface area: 64 lbs/sq ft or 310 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.97
      - Longitudinal: 1.37
      - 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

8 submerged torpedo tubes; 4 on each beam
tubes are canted outwards 45 degrees from centerline
3 torpedoes per tube; one in tube + 2 reloads per tube

[Borys]

Ahoj!
IMO put the tubes on deck.
http://www.kuk-kriegsmarine.at/
click on "schiffe", then "rapidkreuzer"
Borys

[Carthaginian]

Right now, the idea is that the ship's firepower will be 'camouflaged' in the underwater tubes, in addition to being more well protected by being placed below the armored deck. Not the best decision, but as these are being envisioned for defense of the Gulf, the fact that they are slightly more cramped is tolerable.

The performance of this class will be analyzed before the next group is constructed, and if attitudes change, then the above deck tubes will possibly be adopted then.

[maddox]

Kitikamen anyone?

One of the reasons that in the N-verse anyone would use ships like this is a torough analysation of the ambush at Yantai.  Problem is. New Swiss didn't advertise its losses there, and the Middle Kingdom introvert as always didn't tell it either.

The other event that gives torpedo's a reason to excist, is the sinking of Neptune, where 4 ACM torpedo's struck the battleship and sunk it.  But again, this was swept under the rugs...

And camoflaged firepower...... Talk to the MK about that. If you can get any contanct.... 14 underwatertubes on small CCBB's.

[Carthaginian]

Well, Maddox, I didn't intend to camouflage THAT much firepower... but you are giving me ideas. Maybe I can design something like that later on, when I get back home form camp, and when I have some decent fleet BB's to replace my pre-dreads.

[Borys]

Ahoj!
Azores, Panzerkreuzer SMS Prag - sunk by single torpedo.
Borys