Here's a ship that I put together as part of a larger AU that I'm working on. It's not in Shipbucket style/format (it is '2 pixel:1 foot' scale, 'cause that's all I draw in anyway); but if it seems I can bring it (and the others that I'm planning) up to Shipbucket standards without too much extra work, I might go for it. I have an entire alternative history worked out for the setup, and the ships follow it.
The
Tennessee was the first 'modern' Confederate battleship. Similar to the British
Royal Sovereign class, these ships have open barbette mountings and fixed loading angles and positions. The Tredgar Armory 13"/L34 '1000-pounder' main guns were the largest that the Confederacy could produce domestically; British 13.5"/L35 guns were considered undesirable due to the requirements of 1.) Royal Navy construction having priority and 2.) slowly straining relations between the Confederacy and British Empire over the so-called 'Cotton Laws.' Secondary armament was limited to only eight domestically produced Selma Iron Works 6.4"/L35 '125-pounder' breech loaders. On the
Tennessee class, unlike on their British cousins, these were provided with fully enclosed positions with local armor of 4" and 2" splinter protection for backs and sides.
Protection was extremely important, with the main belt being fully 10' high and 14" thick, extending for 212' of the ship's overall 350' length. An upper belt of 8" ran the 142' between the fore and aft barbettes, and 3" armor protected the ends outside the main belt. The armored deck was 3" thick, extending from the end of the raised fo'c'sle to 50' short of the stern. The conning tower was 14" thick and two decks high.
The
Tennessee's greatest downfall were their engineering plant. At a time when triple-expansion engines dominated naval engineering, the Confederacy deliberately used single-expansion plants in these ships to lessen maintenance costs. This resulted in a rather large portion of the vessel being devoted to propulsion, and as such the space below the armored deck was extremely cramped.
SPRINGSHARP REPORT
Tennessee, Confederate States of America Ironclad laid down 1886
Barbette ship
Displacement:
9,600 t light; 9,990 t standard; 10,800 t normal; 11,448 t full load
Dimensions: Length overall / water x beam x draught
350.00 ft / 350.00 ft x 70.00 ft x 24.00 ft (normal load)
106.68 m / 106.68 m x 21.34 m x 7.32 m
Armament:
4 - 13.00" / 330 mm guns (2x2 guns), 1,000.00lbs / 453.59kg shells, 1886 Model
Breech loading guns in open barbettes
on centreline ends, evenly spread
8 - 6.40" / 163 mm guns in single mounts, 125.00lbs / 56.70kg shells, 1886 Model
Breech loading guns in deck mounts
on side, all amidships
10 - 2.25" / 57.2 mm guns in single mounts, 5.00lbs / 2.27kg shells, 1886 Model
Quick firing guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 5,050 lbs / 2,291 kg
Shells per gun, main battery: 60
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 14.0" / 356 mm 212.00 ft / 64.62 m 10.00 ft / 3.05 m
Ends: 3.00" / 76 mm 138.00 ft / 42.06 m 10.00 ft / 3.05 m
Upper: 8.00" / 203 mm 142.00 ft / 43.28 m 8.00 ft / 2.44 m
Main Belt covers 93 % of normal length
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: - - 12.0" / 305 mm
2nd: 4.00" / 102 mm 2.00" / 51 mm -
3rd: 0.25" / 6 mm - -
- Armour deck: 3.00" / 76 mm, Conning tower: 14.00" / 356 mm
Machinery:
Coal fired boilers, simple reciprocating steam engines,
Direct drive, 2 shafts, 8,300 ihp / 6,192 Kw = 16.03 kts
Range 4,120nm at 10.00 kts
Bunker at max displacement = 1,458 tons (100% coal)
Complement:
529 - 688
Cost:
£1.105 million / $4.418 million
Distribution of weights at normal displacement:
Armament: 646 tons, 6.0 %
Armour: 3,921 tons, 36.3 %
- Belts: 2,000 tons, 18.5 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 739 tons, 6.8 %
- Armour Deck: 1,035 tons, 9.6 %
- Conning Tower: 147 tons, 1.4 %
Machinery: 1,612 tons, 14.9 %
Hull, fittings & equipment: 3,340 tons, 30.9 %
Fuel, ammunition & stores: 1,200 tons, 11.1 %
Miscellaneous weights: 80 tons, 0.7 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
10,072 lbs / 4,569 Kg = 9.8 x 13.0 " / 330 mm shells or 1.6 torpedoes
Stability (Unstable if below 1.00): 1.35
Metacentric height 5.0 ft / 1.5 m
Roll period: 13.2 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.29
Seaboat quality (Average = 1.00): 1.49
Hull form characteristics:
Hull has raised forecastle
Block coefficient: 0.643
Length to Beam Ratio: 5.00 : 1
'Natural speed' for length: 18.71 kts
Power going to wave formation at top speed: 47 %
Trim (Max stability = 0, Max steadiness = 100): 47
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: 15.00 ft / 4.57 m
- Forecastle (14 %): 15.00 ft / 4.57 m (12.00 ft / 3.66 m aft of break)
- Mid (50 %): 12.00 ft / 3.66 m
- Quarterdeck (14 %): 12.00 ft / 3.66 m
- Stern: 12.00 ft / 3.66 m
- Average freeboard: 12.43 ft / 3.79 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 93.0 %
- Above water (accommodation/working, high = better): 80.6 %
Waterplane Area: 18,646 Square feet or 1,732 Square metres
Displacement factor (Displacement / loading): 87 %
Structure weight / hull surface area: 130 lbs/sq ft or 637 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.91
- Longitudinal: 2.18
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is cramped
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily