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1

Friday, February 15th 2008, 8:05am

Bulgarian Torpedo Boats

I've been poking around through the current Bulgarian list of ships, and my eight German-designed torpedo boats are rather lacking a Springsharp.

They are based off the T35.

I tried to get everything according to the Design Rules, but these things don't want to give me a very good result. Which, I'd suppose, is historical... but can you folks spot some improvements? I tried raising the freeboard but then my cross-sectional hull strength dips below .5 :-/

Hristo Botev, Bulgarian Torpedo Boat laid down 1933

Displacement:
757 t light; 777 t standard; 845 t normal; 898 t full load

Dimensions: Length overall / water x beam x draught
281.41 ft / 276.57 ft x 28.28 ft x 9.28 ft (normal load)
85.77 m / 84.30 m x 8.62 m x 2.83 m

Armament:
1 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1933 Model
Breech loading gun in deck mount
on centreline aft
1 - 1.46" / 37.0 mm guns in single mounts, 1.55lbs / 0.70kg shells, 1933 Model
Breech loading gun in deck mount
on side forward
2 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1933 Model
Breech loading guns in deck mounts
on side, evenly spread
Weight of broadside 37 lbs / 17 kg
Shells per gun, main battery: 150
6 - 21.0" / 533.4 mm above water torpedoes

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 37,305 shp / 27,830 Kw = 35.00 kts
Range 1,200nm at 19.00 kts
Bunker at max displacement = 121 tons

Complement:
77 - 101

Cost:
£0.467 million / $1.868 million

Distribution of weights at normal displacement:
Armament: 5 tons, 0.6 %
Machinery: 488 tons, 57.8 %
Hull, fittings & equipment: 264 tons, 31.3 %
Fuel, ammunition & stores: 87 tons, 10.3 %
Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
195 lbs / 88 Kg = 5.5 x 4.1 " / 105 mm shells or 0.2 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 0.9 ft / 0.3 m
Roll period: 12.5 seconds
Steadiness - As gun platform (Average = 50 %): 52 %
- Recoil effect (Restricted arc if above 1.00): 0.06
Seaboat quality (Average = 1.00): 0.57

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.407
Length to Beam Ratio: 9.78 : 1
'Natural speed' for length: 16.63 kts
Power going to wave formation at top speed: 74 %
Trim (Max stability = 0, Max steadiness = 100): 91
Bow angle (Positive = bow angles forward): 15.00 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 %): 10.99 ft / 3.35 m
- Mid (50 %): 10.99 ft / 3.35 m
- Quarterdeck (15 %): 10.99 ft / 3.35 m
- Stern: 10.99 ft / 3.35 m
- Average freeboard: 11.56 ft / 3.52 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 190.9 %
- Above water (accommodation/working, high = better): 62.0 %
Waterplane Area: 4,835 Square feet or 449 Square metres
Displacement factor (Displacement / loading): 38 %
Structure weight / hull surface area: 29 lbs/sq ft or 143 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.91
- Overall: 0.57
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is cramped
Caution: Lacks seaworthiness - very limited seakeeping ability

2

Friday, February 15th 2008, 11:27am

The WW T-1 type can be found here: http://88.198.26.117/kunden/oponn/wbblit…eadid=3191&sid= they're (currently) the last entry.

3

Friday, February 15th 2008, 3:49pm

Quoted

I tried to get everything according to the Design Rules, but these things don't want to give me a very good result. Which, I'd suppose, is historical... but can you folks spot some improvements? I tried raising the freeboard but then my cross-sectional hull strength dips below .5 :-/


Well, maybe someone else can do better than me with this one:

Hristo Botev, Bulgaria Torpedo Boat laid down 1933

Displacement:
757 t light; 777 t standard; 837 t normal; 885 t full load

Dimensions: Length overall / water x beam x draught
288.74 ft / 283.46 ft x 26.25 ft x 9.84 ft (normal load)
88.01 m / 86.40 m x 8.00 m x 3.00 m

Armament:
1 - 4.13" / 105 mm guns in single mounts, 35.32lbs / 16.02kg shells, 1933 Model
Dual purpose gun in deck mount
on centreline aft
1 - 1.46" / 37.0 mm guns in single mounts, 1.55lbs / 0.70kg shells, 1933 Model
Anti-aircraft gun in deck mount
on centreline forward
2 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1933 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 37 lbs / 17 kg
Shells per gun, main battery: 150
6 - 21.0" / 533.4 mm above water torpedoes

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 29,324 shp / 21,876 Kw = 35.00 kts
Range 1,200nm at 19.00 kts
Bunker at max displacement = 107 tons

Complement:
77 - 101

Cost:
£0.449 million / $1.796 million

Distribution of weights at normal displacement:
Armament: 5 tons, 0.6%
Machinery: 461 tons, 55.1%
Hull, fittings & equipment: 282 tons, 33.6%
Fuel, ammunition & stores: 80 tons, 9.5%
Miscellaneous weights: 10 tons, 1.2%

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
240 lbs / 109 Kg = 6.8 x 4.1 " / 105 mm shells or 0.2 torpedoes
Stability (Unstable if below 1.00): 1.20
Metacentric height 0.9 ft / 0.3 m
Roll period: 11.4 seconds
Steadiness - As gun platform (Average = 50 %): 51 %
- Recoil effect (Restricted arc if above 1.00): 0.07
Seaboat quality (Average = 1.00): 0.80

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.400
Length to Beam Ratio: 10.80 : 1
'Natural speed' for length: 19.35 kts
Power going to wave formation at top speed: 72 %
Trim (Max stability = 0, Max steadiness = 100): 64
Bow angle (Positive = bow angles forward): 15.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 19.69 ft / 6.00 m
- Forecastle (20%): 12.14 ft / 3.70 m
- Mid (50%): 12.14 ft / 3.70 m
- Quarterdeck (15%): 12.14 ft / 3.70 m
- Stern: 12.14 ft / 3.70 m
- Average freeboard: 12.74 ft / 3.88 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 183.4%
- Above water (accommodation/working, high = better): 63.4%
Waterplane Area: 4,753 Square feet or 442 Square metres
Displacement factor (Displacement / loading): 48%
Structure weight / hull surface area: 27 lbs/sq ft or 134 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 2.85
- Overall: 0.59
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is cramped
Poor seaboat, wet and uncomfortable, reduced performance in heavy weather