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Tuesday, March 13th 2012, 9:05pm

Bulgarian Ships for 1942

There will only be one new vessel laid down by Bulgaria in 1942.

Quoted

[SIZE=3]Trigradsko zhdrelo, Bulgarian Training Ship laid down 1942[/SIZE]
The Trigradsko zhdrelo is designed to serve as a small training vessel for use by navigators, deck officers, antiaircraft gunners, and antisubmarine specialists. Secondary use will be hydrographic survey and inspection duties.

Displacement:
187 t light; 215 t standard; 288 t normal; 346 t full load

Dimensions: Length overall / water x beam x draught
172.25 ft / 154.20 ft x 23.29 ft x 6.56 ft (normal load)
52.50 m / 47.00 m x 7.10 m x 2.00 m

Armament:
4 - 1.57" / 40.0 mm guns in single mounts, 1.95lbs / 0.89kg shells, 1942 Model
Anti-aircraft guns in deck mounts
on centreline ends, evenly spread, 2 raised mounts - superfiring
4 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1942 Model
Anti-aircraft guns in deck mounts
on side, all amidships
Weight of broadside 9 lbs / 4 kg
Shells per gun, main battery: 4,000

Machinery:
Diesel Internal combustion generators,
Electric motors, 2 shafts, 1,017 shp / 759 Kw = 16.00 kts
Range 4,500nm at 15.00 kts
Bunker at max displacement = 131 tons

Complement:
34 - 45

Cost:
£0.071 million / $0.285 million

Distribution of weights at normal displacement:
Armament: 1 tons, 0.4 %
Machinery: 27 tons, 9.2 %
Hull, fittings & equipment: 106 tons, 36.9 %
Fuel, ammunition & stores: 101 tons, 35.1 %
Miscellaneous weights: 53 tons, 18.4 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
676 lbs / 307 Kg = 346.3 x 1.6 " / 40 mm shells or 0.7 torpedoes
Stability (Unstable if below 1.00): 1.21
Metacentric height 0.8 ft / 0.2 m
Roll period: 11.0 seconds
Steadiness - As gun platform (Average = 50 %): 81 %
- Recoil effect (Restricted arc if above 1.00): 0.03
Seaboat quality (Average = 1.00): 1.85

Hull form characteristics:
Hull has raised forecastle
Block coefficient: 0.428
Length to Beam Ratio: 6.62 : 1
'Natural speed' for length: 12.42 kts
Power going to wave formation at top speed: 56 %
Trim (Max stability = 0, Max steadiness = 100): 44
Bow angle (Positive = bow angles forward): 35.00 degrees
Stern overhang: 6.56 ft / 2.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 16.40 ft / 5.00 m
- Forecastle (20 %): 14.76 ft / 4.50 m (7.55 ft / 2.30 m aft of break)
- Mid (50 %): 7.38 ft / 2.25 m
- Quarterdeck (15 %): 7.38 ft / 2.25 m
- Stern: 7.87 ft / 2.40 m
- Average freeboard: 9.05 ft / 2.76 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 62.0 %
- Above water (accommodation/working, high = better): 93.6 %
Waterplane Area: 2,252 Square feet or 209 Square metres
Displacement factor (Displacement / loading): 251 %
Structure weight / hull surface area: 27 lbs/sq ft or 133 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.86
- Longitudinal: 3.86
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Breakdown of Miscellaneous Weights:
- 15 tons for ASW gear and practice depth charges
- 35 tons for trainee officers and crew
- 3 tons for communications equipment

2

Tuesday, March 13th 2012, 9:14pm

She's almost 50% oil at full load. Seems rather excessive.

I like the utility of the ship, though.

3

Tuesday, March 13th 2012, 9:20pm

Quoted

Originally posted by The Rock Doctor
She's almost 50% oil at full load. Seems rather excessive.

Hum. Kinda forgot to pay attention to that, actually. I suppose I could write that off as "deep-stowed ballast in the cargo hold" or something like that.

I was actually trying to get a ship with a very exacting light displacement, as I'm going to spend all of Bulgaria's 1942 production on IP - so I needed to "use or lose" precisely 187 tons. This seemed to be the most efficient way of doing so.

4

Tuesday, March 13th 2012, 9:37pm

I can understand that challenge...