Design Competition: 200 ton Torpedo Boat

[Kaiser Kirk]

Presuming no one finds some flaw I missed, I see no problems with that arrangement.

[damocles]

Presuming no one finds some flaw I missed, I see no problems with that arrangement.

FAC-200-1, Hoilland torpedojager laid down 1920

Displacement:
   199 t light; 204 t standard; 228 t normal; 247 t full load

Dimensions: Length overall / water x beam x draught
   203.87 ft / 198.00 ft x 18.00 ft x 5.60 ft (normal load)
   62.14 m / 60.35 m x 5.49 m  x 1.71 m

Armament:
     1 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1920 Model
     Quick firing gun in deck mount
     on centreline aft
     4 - 0.59" / 15.0 mm guns (1x4 guns), 0.10lbs / 0.05kg shells, 1920 Model
     Machine guns in deck mount
     on centreline aft
   Weight of broadside 13 lbs / 6 kg
   Shells per gun, main battery: 150
   3 - 21.0" / 530 mm submerged torpedo tubes

Armour:
  - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.39" / 10 mm   0.39" / 10 mm            -

Machinery:
   Diesel Internal combustion generators,
   Electric motors, 2 shafts, 4,491 shp / 3,350 Kw = 25.00 kts
   Range 2,600nm at 12.00 kts
   Bunker at max displacement = 43 tons

Complement:
   29 - 38

Cost:
   £0.056 million / $0.225 million

Distribution of weights at normal displacement:
   Armament: 2 tons, 0.7 %
   Armour: 1 tons, 0.4 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 1 tons, 0.4 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 110 tons, 48.4 %
   Hull, fittings & equipment: 74 tons, 32.3 %
   Fuel, ammunition & stores: 30 tons, 12.9 %
   Miscellaneous weights: 12 tons, 5.3 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     26 lbs / 12 Kg = 2.0 x 3.0 " / 75 mm shells or 0.1 torpedoes
   Stability (Unstable if below 1.00): 1.07
   Metacentric height 0.4 ft / 0.1 m
   Roll period: 11.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 94 %
         - Recoil effect (Restricted arc if above 1.00): 0.10
   Seaboat quality  (Average = 1.00): 1.16

Hull form characteristics:
   Hull has raised forecastle
   Block coefficient: 0.400
   Length to Beam Ratio: 11.00 : 1
   'Natural speed' for length: 14.07 kts
   Power going to wave formation at top speed: 64 %
   Trim (Max stability = 0, Max steadiness = 100): 81
   Bow angle (Positive = bow angles forward): 20.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      16.14 ft / 4.92 m
      - Forecastle (20 %):   14.50 ft / 4.42 m (6.59 ft / 2.01 m aft of break)
      - Mid (50 %):      6.59 ft / 2.01 m
      - Quarterdeck (15 %):   6.59 ft / 2.01 m
      - Stern:      6.59 ft / 2.01 m
      - Average freeboard:   8.30 ft / 2.53 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 281.7 %
      - Above water (accommodation/working, high = better): 95.0 %
   Waterplane Area: 2,194 Square feet or 204 Square metres
   Displacement factor (Displacement / loading): 67 %
   Structure weight / hull surface area: 16 lbs/sq ft or 80 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.54
      - Longitudinal: 1.99
      - Overall: 0.62
   Hull space for machinery, storage, compartmentation is extremely poor
   Room for accommodation and workspaces is adequate
   Ship has slow, easy roll, a good, steady gun platform

12 tons misc.
3 TT (1 reload).
trial  speed=30 knots
Experimental patrol boat designed to incorporate, torpedo tubes with reloads in the hull.

First Illustration is the export model.
Second is the Dutch Standard.

 Consider this my design entry but with 4 x 17.7 inch torpedo tubes and 1 reload.

[Kaiser Kirk]

Nice pic :)

[damocles]

Nice pic :)

Thanks.

[TexanCowboy]

Reloads on a 200 ton boat?  :D :D :D

[Nobody]

Reloads on a 200 ton boat?  :D :D :D

Where's the problem with that?
German S-Boats always carried reloads, even the early versions which were considerably smaller than 100 tons (normal/standard/max).

[TexanCowboy]

At this point, it would be incredibly hard to reload torpedoes on a boat this size without mechanical assistance. You could set it up like the Japanese destroyers, adding the reload at an angle where the release of a lever would knock it into the tube. However, that takes up deckspace, and it would greatly add to the risk of explosion. You could alternatively set it up like the American destroyers, adding the reload below deck, but that would take up crew space, and it would take 2-3 hours, with hard labor and pulleys, to reload.

The S-boats had them, IIRC, because they were meant to operate from shallow coastal beaches and sandbars, and the equivelent, without tenders, leading them to have the ability to reload. In addition, with only two torpedo tubes, even if of a bigger type, they had the additional room nessasary to stow the extra torpedoes, below deck.

[damocles]

At this point, it would be incredibly hard to reload torpedoes on a boat this size without mechanical assistance. You could set it up like the Japanese destroyers, adding the reload at an angle where the release of a lever would knock it into the tube. However, that takes up deckspace, and it would greatly add to the risk of explosion. You could alternatively set it up like the American destroyers, adding the reload below deck, but that would take up crew space, and it would take 2-3 hours, with hard labor and pulleys, to reload.

The S-boats had them, IIRC, because they were meant to operate from shallow coastal beaches and sandbars, and the equivelent, without tenders, leading them to have the ability to reload. In addition, with only two torpedo tubes, even if of a bigger type, they had the additional room nessasary to stow the extra torpedoes, below deck.

The second drawing indicates the track and trolley truck reload system drawn in for the Dutch boats. The torpedoes are stored above deck and chute fed down roller rails into the tubes.

Its feasible and it makes a certain sense as it fits in with Dutch tactical doctrine as it slowly emerges from the Siam war.     

[TexanCowboy]

That's going to interfer with the 75 mm gun's firing angles.

[damocles]

That's going to interfer with the 75 mm gun's firing angles.

How? The torps are ahead of the 75 and well below its zero horizon reference.

[Jefgte]

CTBM200 from NUS

[ctwaterman]

Some Nice Designs there Kirk and Jefgte