An attempt with a sub. A exprimental submarine cruiser (like the X-1) from 1918. The HMUb (His Majesty's Submarine) Jona, in service 1923-1942.

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**Jona**

(*Odysseus*)

Sweden

Submarine Cruiser laid down 1918

Displacement:

1 754 t light; 1 805 t standard; 2 000 t normal; 2 156 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)

(278,96 ft / 278,87 ft) x 26,25 ft x (19,69 / 20,82 ft)

(85,03 m / 85,00 m) x 8,00 m x (6,00 / 6,35 m)

Armament:

2 - 5,98" / 152 mm 30,0 cal guns - 98,76lbs / 44,80kg shells, 80 per gun

Breech loading guns in deck and hoist mounts, 1918 Model

2 x Single mounts on centreline, forward deck aft

4 - 2,24" / 57,0 mm 45,0 cal guns - 5,70lbs / 2,58kg shells, 150 per gun

Quick firing guns in deck mounts, 1918 Model

4 x Single mounts on sides, forward deck aft

4 raised mounts

Weight of broadside 220 lbs / 100 kg

Main Torpedoes

6 - 21,0" / 533 mm, 26,25 ft / 8,00 m torpedoes - 1,662 t each, 9,972 t total

submerged bow tubes

2nd Torpedoes

2 - 21,0" / 533 mm, 22,97 ft / 7,00 m torpedoes - 1,468 t each, 2,937 t total

submerged bow & stern tubes

Armour:

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)

Main: 0,79" / 20 mm 0,79" / 20 mm 0,39" / 10 mm

Machinery:

Diesel Internal combustion engines plus batteries,

Electric cruising motors plus geared drives, 2 shafts, 4 363 shp / 3 255 Kw = 18,00 kts

Range 8 000nm at 10,00 kts

Bunker at max displacement = 351 tons

Complement:

75-90

Cost:

£0,194 million / $0,777 million

Operational depth: 230ft/ 69m

Emerg. dive depth: 345ft/ 103m

Crush depth: 575ft/ 172m

Distribution of weights at normal displacement:

Armament: 65 tons, 3,3 %

- Guns: 40 tons, 2,0 %

- Weapons: 26 tons, 1,3 %

Armour: 12 tons, 0,6 %

- Armament: 12 tons, 0,6 %

Machinery: 157 tons, 7,9 %

Hull, fittings & equipment: 1 019 tons, 51,0 %

Fuel, ammunition & stores: 246 tons, 12,3 %

Miscellaneous weights: 500 tons, 25,0 %

- Hull below water: 500 tons

Overall survivability and seakeeping ability:

Survivability (Non-critical penetrating hits needed to sink ship):

1 490 lbs / 676 Kg = 13,9 x 6,0 " / 152 mm shells or 0,5 torpedoes

Stability (Unstable if below 1.00): 1,10

Metacentric height 0,8 ft / 0,2 m

Roll period: 12,2 seconds

Steadiness - As gun platform (Average = 50 %): 2 %

- Recoil effect (Restricted arc if above 1.00): 0,03

Seaboat quality (Average = 1.00): 0,00

Hull form characteristics:

Hull has a flush deck,

a normal bow and a cruiser stern

Block coefficient (normal/deep): 0,486 / 0,495

Length to Beam Ratio: 10,63 : 1

'Natural speed' for length: 16,70 kts

Power going to wave formation at top speed: 43 %

Trim (Max stability = 0, Max steadiness = 100): 50

Bow angle (Positive = bow angles forward): 15,00 degrees

Stern overhang: 0,00 ft / 0,00 m

Freeboard (% = length of deck as a percentage of waterline length):

Fore end, Aft end

- Forecastle: 20,00 %, 0,33 ft / 0,10 m, 0,33 ft / 0,10 m

- Forward deck: 30,00 %, 0,33 ft / 0,10 m, 0,33 ft / 0,10 m

- Aft deck: 35,00 %, 0,33 ft / 0,10 m, 0,33 ft / 0,10 m

- Quarter deck: 15,00 %, 0,33 ft / 0,10 m, 0,33 ft / 0,10 m

- Average freeboard: 0,33 ft / 0,10 m

Ship tends to be wet forward

Ship space, strength and comments:

Space - Hull below water (magazines/engines, low = better): 72,1 %

- Above water (accommodation/working, high = better): 2,0 %

Waterplane Area: 4 815 Square feet or 447 Square metres

Displacement factor (Displacement / loading): 209 %

Structure weight / hull surface area: 131 lbs/sq ft or 637 Kg/sq metre

Hull strength (Relative):

- Cross-sectional: 2,61

- Longitudinal: 2,21

- Overall: 2,30

Excellent machinery, storage, compartmentation space

Extremely poor accommodation and workspace room

Ship has quick, lively roll, not a steady gun platform

Caution: Lacks seaworthiness - very limited seakeeping ability