WesWorld

A large MTB for baltic or Caribean work



T-10, Sweden Torpedoboat laid down 1926

Displacement:
630 t light; 644 t standard; 670 t normal; 691 t full load

Dimensions: Length overall / water x beam x draught
267,11 ft / 252,62 ft x 26,25 ft x 9,84 ft (normal load)
81,41 m / 77,00 m x 8,00 m x 3,00 m

Armament:
2 - 2,24" / 57,0 mm guns (1x2 guns), 5,65lbs / 2,56kg shells, 1918 Model
Dual purpose guns in deck mount
on centreline forward
8 - 0,51" / 13,0 mm guns (2x4 guns), 0,07lbs / 0,03kg shells, 1925 Model
Machine guns in deck mounts
on centreline, evenly spread
Weight of broadside 12 lbs / 5 kg
Shells per gun, main battery: 150
6 - 21,0" / 533 mm above water torpedoes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0,20" / 5 mm - -
2nd: 0,12" / 3 mm - -

Machinery:
Diesel Internal combustion motors,
Direct drive, 3 shafts, 37 731 shp / 28 147 Kw = 38,00 kts
Range 800nm at 16,00 kts (Bunkerage = 47 tons)
Caution: Delicate, lightweight machinery

Complement:
65 - 85

Cost:
£0,271 million / $1,085 million

Distribution of weights at normal displacement:
Armament: 1 tons, 0,2 %
Armour: 0 tons, 0,1 %
- Belts: 0 tons, 0,0 %
- Torpedo bulkhead: 0 tons, 0,0 %
- Armament: 0 tons, 0,1 %
- Armour Deck: 0 tons, 0,0 %
- Conning Tower: 0 tons, 0,0 %
Machinery: 395 tons, 58,9 %
Hull, fittings & equipment: 223 tons, 33,3 %
Fuel, ammunition & stores: 40 tons, 6,0 %
Miscellaneous weights: 10 tons, 1,5 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
134 lbs / 61 Kg = 23,6 x 2,2 " / 57 mm shells or 0,2 torpedoes
Stability (Unstable if below 1.00): 1,00
Metacentric height 0,7 ft / 0,2 m
Roll period: 13,4 seconds
Steadiness - As gun platform (Average = 50 %): 46 %
- Recoil effect (Restricted arc if above 1.00): 0,03
Seaboat quality (Average = 1.00): 0,53

Hull form characteristics:
Hull has raised forecastle
and transom stern
Block coefficient: 0,359
Length to Beam Ratio: 9,63 : 1
'Natural speed' for length: 18,57 kts
Power going to wave formation at top speed: 78 %
Trim (Max stability = 0, Max steadiness = 100): 81
Bow angle (Positive = bow angles forward): 40,00 degrees
Stern overhang: 0,00 ft / 0,00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 17,26 ft / 5,26 m
- Forecastle (30 %): 16,40 ft / 5,00 m (10,99 ft / 3,35 m aft of break)
- Mid (50 %): 10,99 ft / 3,35 m
- Quarterdeck (20 %): 10,99 ft / 3,35 m
- Stern: 10,99 ft / 3,35 m
- Average freeboard: 12,72 ft / 3,88 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 193,4 %
- Above water (accommodation/working, high = better): 50,7 %
Waterplane Area: 4 174 Square feet or 388 Square metres
Displacement factor (Displacement / loading): 27 %
Structure weight / hull surface area: 25 lbs/sq ft or 121 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,41
- Longitudinal: 3,54
- Overall: 0,50
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is cramped
Caution: Lacks seaworthiness - very limited seakeeping ability

If it was 5-10 times smaller, you'd have a good design.

She is intened to be a large Torpedoboat like the Plejad-class of 1955. She is quite big, I made a new attemt,

T-test, Sweden MTB laid down 1928

Displacement:
398 t light; 408 t standard; 420 t normal; 430 t full load

Dimensions: Length overall / water x beam x draught
199,64 ft / 187,01 ft x 24,61 ft x 9,84 ft (normal load)
60,85 m / 57,00 m x 7,50 m x 3,00 m

Armament:
2 - 2,24" / 57,0 mm guns (1x2 guns), 5,65lbs / 2,56kg shells, 1928 Model
Quick firing guns in a deck mount with hoist
on centreline forward
8 - 0,51" / 13,0 mm guns (2x4 guns), 0,07lbs / 0,03kg shells, 1928 Model
Machine guns in deck mounts
on centreline, evenly spread
Weight of broadside 12 lbs / 5 kg
Shells per gun, main battery: 150
6 - 21,0" / 533 mm above water torpedoes

Machinery:
Petrol Internal combustion motors,
Geared drive, 3 shafts, 23 102 shp / 17 234 Kw = 35,00 kts
Range 350nm at 18,00 kts (Bunkerage = 22 tons)
Caution: Delicate, lightweight machinery

Complement:
46 - 60

Cost:
£0,186 million / $0,745 million

Distribution of weights at normal displacement:
Armament: 1 tons, 0,4 %
Machinery: 240 tons, 57,2 %
Hull, fittings & equipment: 146 tons, 34,9 %
Fuel, ammunition & stores: 22 tons, 5,2 %
Miscellaneous weights: 10 tons, 2,4 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
96 lbs / 43 Kg = 16,9 x 2,2 " / 57 mm shells or 0,1 torpedoes
Stability (Unstable if below 1.00): 1,01
Metacentric height 0,6 ft / 0,2 m
Roll period: 13,1 seconds
Steadiness - As gun platform (Average = 50 %): 27 %
- Recoil effect (Restricted arc if above 1.00): 0,06
Seaboat quality (Average = 1.00): 0,27

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0,325
Length to Beam Ratio: 7,60 : 1
'Natural speed' for length: 16,47 kts
Power going to wave formation at top speed: 81 %
Trim (Max stability = 0, Max steadiness = 100): 55
Bow angle (Positive = bow angles forward): 35,00 degrees
Stern overhang: 0,00 ft / 0,00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 18,04 ft / 5,50 m
- Forecastle (20 %): 16,40 ft / 5,00 m
- Mid (50 %): 9,58 ft / 2,92 m
- Quarterdeck (15 %): 9,58 ft / 2,92 m
- Stern: 9,58 ft / 2,92 m
- Average freeboard: 12,10 ft / 3,69 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 189,9 %
- Above water (accommodation/working, high = better): 14,0 %
Waterplane Area: 2 938 Square feet or 273 Square metres
Displacement factor (Displacement / loading): 29 %
Structure weight / hull surface area: 23 lbs/sq ft or 113 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,38
- Longitudinal: 6,43
- Overall: 0,51
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is extremely poor
Ship has quick, lively roll, not a steady gun platform
Caution: Lacks seaworthiness - very limited seakeeping ability

I've been trying for a similar thing for Greece but the delicate lightweight machinery gives me reason to pause. I'd used a curved armoured deck over the machinery (also delicate lightweight)in my first series of TB (it actually helped with stability) but I've now gone to just the mini-destroyer idea at only 32knts and more robust machinery but I did retain 2 of the TT fixed.

Petrol engines to drive something this large?

Cheers,

Hull strength is way, way, way too low.

Cross-sectional hull strength should be at least 0.50...