Confederate Depot Ship

[Carthaginian]

Opinions...?


Realizing the need for support ships and infrastructure, the Confederate Navy has observed other navies as they created such ships and has now begun putting forth it's own designs for dedicated support ships. The Ingalls class depot ship is a small, fully mobile naval base in it's own right, capable of supporting a destroyer or patrol flotilla for extended periods of time with little or no strain on it's facilities.

Carrying over 3400t of fuel oil, the ship's massive bunkers have enough fuel for virtually any ship in the Confederate Navy to top off, and still allowing for the ship itself to make trans-Atlantic voyages. Large quantities of ammunition and torpedoes also are carried, enabling the Ingals to support combat operations even at the high tempo of modern warfare. Two 9000shp turbines can propel the ship at fleet speeds (in excess of 20 knots), while a single 2000shp VTE cruising engine can provide a cruise speed of slightly over 10 knots.

The ship is also armed against TB and destroyer attack, and includes anti-airship guns and machine guns for use against light targets.

*picture forthcoming*


Ingalls, Confederate States of America Light Depot Ship laid down 1910 (Engine 1909)

Displacement:
   4,000 t light; 4,187 t standard; 7,592 t normal; 10,316 t full load

Dimensions: Length overall / water x beam x draught
   350.00 ft / 350.00 ft x 50.00 ft x 24.00 ft (normal load)
   106.68 m / 106.68 m x 15.24 m  x 7.32 m

Armament:
      2 - 3.50" / 88.9 mm guns in single mounts, 25.00lbs / 11.34kg shells, 1909 Model
     Quick firing guns in deck mounts
     on centreline ends, evenly spread
      4 - 3.50" / 88.9 mm guns in single mounts, 25.00lbs / 11.34kg shells, 1909 Model
     Quick firing guns in deck mounts
     on side, evenly spread
      2 - 3.50" / 88.9 mm guns in single mounts, 25.00lbs / 11.34kg shells, 1910 Model
     Anti-airship guns in deck mounts
     on centreline, evenly spread, all raised mounts
      4 - 1.00" / 25.4 mm guns (2x2 guns), 0.50lbs / 0.23kg shells, 1910 Model
     Machine guns in deck mounts
     on side, all amidships
      4 - 1.00" / 25.4 mm guns (2x2 guns), 0.50lbs / 0.23kg shells, 1910 Model
     Machine guns in deck mounts
     on centreline ends, evenly spread, all raised mounts
   Weight of broadside 204 lbs / 93 kg
   Shells per gun, main battery: 250

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   1.00" / 25 mm   200.00 ft / 60.96 m   16.00 ft / 4.88 m
   Ends:   Unarmoured
     Main Belt covers 88 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.50" / 13 mm         -               -
   2nd:   0.50" / 13 mm         -               -
   3rd:   0.50" / 13 mm         -               -
   4th:   0.25" / 6 mm         -               -
   5th:   0.25" / 6 mm         -               -

   - Armour deck: 0.50" / 13 mm, Conning tower: 0.50" / 13 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 3 shafts, 20,000 shp / 14,920 Kw = 21.59 kts
   Range 33,000nm at 11.70 kts
   Bunker at max displacement = 6,130 tons

Complement:
   406 - 528

Cost:
   £0.286 million / $1.143 million

Distribution of weights at normal displacement:
   Armament: 22 tons, 0.3 %
   Armour: 277 tons, 3.6 %
      - Belts: 143 tons, 1.9 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 8 tons, 0.1 %
      - Armour Deck: 122 tons, 1.6 %
      - Conning Tower: 4 tons, 0.1 %
   Machinery: 909 tons, 12.0 %
   Hull, fittings & equipment: 1,567 tons, 20.6 %
   Fuel, ammunition & stores: 3,592 tons, 47.3 %
   Miscellaneous weights: 1,225 tons, 16.1 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     12,687 lbs / 5,755 Kg = 591.8 x 3.5 " / 89 mm shells or 2.2 torpedoes
   Stability (Unstable if below 1.00): 1.27
   Metacentric height 2.7 ft / 0.8 m
   Roll period: 12.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.03
   Seaboat quality  (Average = 1.00): 1.25

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.633
   Length to Beam Ratio: 7.00 : 1
   'Natural speed' for length: 18.71 kts
   Power going to wave formation at top speed: 59 %
   Trim (Max stability = 0, Max steadiness = 100): 40
   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:      23.00 ft / 7.01 m
      - Forecastle (20 %):   20.00 ft / 6.10 m
      - Mid (50 %):      20.00 ft / 6.10 m (12.00 ft / 3.66 m aft of break)
      - Quarterdeck (15 %):   12.00 ft / 3.66 m
      - Stern:      12.00 ft / 3.66 m
      - Average freeboard:   16.24 ft / 4.95 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 60.0 %
      - Above water (accommodation/working, high = better): 97.1 %
   Waterplane Area: 13,194 Square feet or 1,226 Square metres
   Displacement factor (Displacement / loading): 217 %
   Structure weight / hull surface area: 70 lbs/sq ft or 343 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.91
      - Longitudinal: 2.32
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is adequate
   Good seaboat, rides out heavy weather easily

1225 t Miscellaneous Weight Breakdown:
500t - Parts, Plating, Etc
  50t - Machine Shop Equipment (includes fuel transfer pumps)
140t - Armored Torpedo Reloads (40)
250t - Armored Ammunition Storage
  60t - 2 Kitchens & Food Storage
  10t - Commodore's Quarters
  10t - Commodore's Offices
  50t - Staff Quarters
  50t - Staff Offices
  50t - Repair Crew Quarters
  25t - Transient Quarters
  10t - Heavy Lift Crane
  10t - 2 Whaleboats (5t each)
  10t - Ethanol Fuel

All 'Quarters' entries take into account weight for heads, showers, and other sundry sanitation needs in addition to furniture. Staff officers are 25@2.5t each, repair crews are 25@2.5t each and transients are 50@0.5t each (just a bed and a locker).

[The Rock Doctor]

I think I'd want to see more freeboard, but there's not a lot of tonnage for accommodation and the like, so I guess I can let it slide.

For the hull size - considering you've got fuel pumps, workshops, and all that stuff - I think you're overgunning her. 

The breakdown of miscellaneous weight is greatly appreciated.

[Korpen]

I think I'd want to see more freeboard, but there's not a lot of tonnage for accommodation and the like, so I guess I can let it slide.

For the hull size - considering you've got fuel pumps, workshops, and all that stuff - I think you're overgunning her. 

The breakdown of miscellaneous weight is greatly appreciated.

I think spring sharp works really bad with using only misc weight for accommodations.
This for the same reason it does not work on more modern warships, accommodations are volume, not weight dependent.  After all, a person does only rarely weight even as much as 100kg, and even with food, water and clothing for an indefinite amount of time would not weight all that much more.  Add to this that much of the space are paid for in weight by the freeboard, as that includes the walls, floors and such stuff for the passengers.

Not that I really got any real solution to this problem, but we got to be aware of it.

[Carthaginian]

Rock,

The low freeboard aft was to facilitate movement of supplies; she is either only slightly taller or of equal height to my destroyers. This means that heavy-lifting equipment isn't necessary to pick up or lower things like hull plates or torpedoes. I do have a heavy-lift crane, but it's mostly for the whaleboats.


I did kind of over-gun her, I guess... I might reduce the armament to 2 side-mounted guns rather than 4. I just wanted a ship that could frighten off anything that was shallow-draft enough to come into harbor chasing her. I also put in a rather heavy (for her size) anti-airship armament because she is going to be stationary for long periods of time, and it wouldn't do for aerial reconnaissance assets to escape with her location.


I'll draw her out soon, and see if it'll all fit. If not, she will change. :)