Ronis class, Latvian Destroyer laid down 1940
The Ronis is an export variant of the Russian Pechora class destroyer., laid down for export in 1940 by the Russians. A total of four ships were built over a number of years.
Displacement:
2,106 t light; 2,241 t standard; 2,540 t normal; 2,779 t full load
Dimensions: Length overall / water x beam x draught
409.99 ft / 393.70 ft x 37.40 ft x 15.09 ft (normal load)
124.96 m / 120.00 m x 11.40 m x 4.60 m
Armament:
6 - 5.12" / 130 mm guns (3x2 guns), 79.37lbs / 36.00kg shells, 1940 Model
Automatic rapid fire guns in deck mounts with hoists
on centreline ends, majority forward, 1 raised mount - superfiring
4 - 1.46" / 37.0 mm guns (1x4 guns), 1.55lbs / 0.70kg shells, 1940 Model
Anti-aircraft guns in a deck mount with hoist
on centreline aft, all raised guns - superfiring
8 - 1.46" / 37.0 mm guns (4x2 guns), 1.55lbs / 0.70kg shells, 1940 Model
Anti-aircraft guns in deck mounts with hoists
on side, evenly spread
4 - 0.55" / 14.0 mm guns in single mounts, 0.08lbs / 0.04kg shells, 1940 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 495 lbs / 225 kg
Shells per gun, main battery: 300
8 - 20.9" / 530 mm above water torpedoes
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.98" / 25 mm 0.20" / 5 mm -
2nd: 0.98" / 25 mm 0.20" / 5 mm -
3rd: 0.98" / 25 mm 0.20" / 5 mm -
Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 49,907 shp / 37,231 Kw = 35.00 kts
Range 4,000nm at 18.00 kts
Bunker at max displacement = 538 tons
Complement:
178 - 232
Cost:
£1.746 million / $6.983 million
Distribution of weights at normal displacement:
Armament: 63 tons, 2.5 %
Armour: 13 tons, 0.5 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 13 tons, 0.5 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 1,176 tons, 46.3 %
Hull, fittings & equipment: 753 tons, 29.7 %
Fuel, ammunition & stores: 434 tons, 17.1 %
Miscellaneous weights: 101 tons, 4.0 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
644 lbs / 292 Kg = 9.6 x 5.1 " / 130 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.12
Metacentric height 1.4 ft / 0.4 m
Roll period: 13.2 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.74
Seaboat quality (Average = 1.00): 1.01
Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.400
Length to Beam Ratio: 10.53 : 1
'Natural speed' for length: 22.85 kts
Power going to wave formation at top speed: 66 %
Trim (Max stability = 0, Max steadiness = 100): 70
Bow angle (Positive = bow angles forward): 25.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 27.89 ft / 8.50 m
- Forecastle (20 %): 19.69 ft / 6.00 m
- Mid (49 %): 19.36 ft / 5.90 m (11.15 ft / 3.40 m aft of break)
- Quarterdeck (15 %): 11.15 ft / 3.40 m
- Stern: 13.12 ft / 4.00 m
- Average freeboard: 16.09 ft / 4.90 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 174.5 %
- Above water (accommodation/working, high = better): 94.5 %
Waterplane Area: 9,407 Square feet or 874 Square metres
Displacement factor (Displacement / loading): 77 %
Structure weight / hull surface area: 40 lbs/sq ft or 197 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 1.86
- Overall: 0.57
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform
Breakdown of Miscellaneous Weights:
Air search radar - 10 tons
Extra machinery and ammo for twin automatic 130mm DP mounts - 30 tons
Asdic - 10 tons
ASW weapons and torpedoes - 51 tons
Ships in Class:
- Ronis: Laid down 1940.
- Imanta: Laid down 1940.
- Visvaldis: Laid down 1943.
- Talivaldis: Laid down 1943.