Czas na uzupełnienia dla flotylli rzecznych na Wiśle i
Niemnie, które – jak widać po przebiegu linii frontu - aktywnie biorą udział w
walkach i wspierają działania własnych wojsk lądowych.
Nowe jednostki należą do dwóch klas – są to małe kanonierki
rzeczne i kutry uzbrojone. Kanonierki są stosunkowo małymi jednostkami o
wyporności 30 ton, ale mają sporą siłę ognia, bowiem noszą pojedynczą haubicę
kal. 100 mm w stanowisku chronionym kolistą pancerną osłoną. Kadłub chroniony
jest 20 mm pancerzem, który powinien zapewnić osłonę przed ogniem broni
strzeleckiej. Okręty są napędzane silnikami diesla i mają relatywnie małe
wymiary i nieduże zanurzenie wynoszące ok 0,5 m, co pozwoli im na znaczną swobodę
w operowaniu na naszych krajowych, niezbyt rozległych i głębokich rzekach.
Z kolei kutry uzbrojone są mikroskopijnymi jednostkami o
wyporności rzędu 5 ton, noszącymi pojedynczy km w stanowisku o konstrukcji
podobnej jak opisane wyżej w przypadku kanonierek. Na uwagę zasługuje fakt, iż
mimo tak mizernych rozmiarów, udało się
te okręciki lekko opancerzyć, dzięki czemu są jako tako zabezpieczone
przynajmniej przed odłamkami.

Czujna, polish river gunboat laid down 1915
Displacement:
28 t light; 29 t standard; 30 t normal; 31 t full load
Dimensions: Length overall / water x beam x draught
59,61 ft / 59,12 ft x 15,91 ft x 1,67 ft (normal load)
18,17 m / 18,02 m x 4,85 m x 0,51 m
Armament:
1 - 3,94" / 100 mm guns in single mounts, 30,51lbs / 13,84kg shells, 1900 Model
Howitzers in a deck mount with hoist
on centreline forward
1 - 1,46" / 37,0 mm guns in single mounts, 1,55lbs / 0,70kg shells, 1914 Model
Quick firing gun in deck mount
on centreline aft
Weight of broadside 31 lbs / 14 kg
Shells per gun, main battery: 120
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 0,79" / 20 mm 30,81 ft / 9,39 m 2,99 ft / 0,91 m
Ends: Unarmoured
Main Belt covers 80% of normal length
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0,59" / 15 mm 0,59" / 15 mm -
2nd: 0,39" / 10 mm - -
Machinery:
Diesel Internal combustion motors,
Hydraulic drive, 1 shaft, 50 shp / 37 Kw = 9,00 kts
Range 450nm at 7,00 kts
Bunker at max displacement = 1 tons
Complement:
12
Cost:
£0,004 million / $0,016 million
Distribution of weights at normal displacement:
Armament: 2 tons, 6,0%
Armour: 5 tons, 17,4%
- Belts: 4 tons, 12,4%
- Torpedo bulkhead: 0 tons, 0,0%
- Armament: 2 tons, 5,1%
- Armour Deck: 0 tons, 0,0%
- Conning Tower: 0 tons, 0,0%
Machinery: 2 tons, 6,3%
Hull, fittings & equipment: 19 tons, 62,6%
Fuel, ammunition & stores: 2 tons, 7,7%
Miscellaneous weights: 0 tons, 0,0%
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
82 lbs / 37 Kg = 6,4 x 3,0 " / 75 mm shells or 0,3 torpedoes
Stability (Unstable if below 1.00): 1,51
Metacentric height 0,6 ft / 0,2 m
Roll period: 8,3 seconds
Steadiness - As gun platform (Average = 50 %): 31 %
- Recoil effect (Restricted arc if above 1.00): 0,11
Seaboat quality (Average = 1.00): 0,38
Hull form characteristics:
Hull has a flush deck
Block coefficient: 0,667
Length to Beam Ratio: 3,72 : 1
'Natural speed' for length: 7,69 kts
Power going to wave formation at top speed: 56 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 0,00 degrees
Stern overhang: 0,49 ft / 0,15 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 2,99 ft / 0,91 m
- Forecastle (20%): 2,99 ft / 0,91 m
- Mid (50%): 2,99 ft / 0,91 m
- Quarterdeck (15%): 2,49 ft / 0,76 m
- Stern: 2,00 ft / 0,61 m
- Average freeboard: 2,79 ft / 0,85 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 66,6%
- Above water (accommodation/working, high = better): 65,5%
Waterplane Area: 724 Square feet or 67 Square metres
Displacement factor (Displacement / loading): 128%
Structure weight / hull surface area: 23 lbs/sq ft or 111 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,91
- Longitudinal: 2,73
- Overall: 1,02
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is cramped
Caution: Lacks seaworthiness - very limited seakeeping ability
Czujna (1915)
Odważna (1915)
Bystra (1915)
Grożna (1915)
Wytrwała (1916)
Szybka (1916)
Gniewna (1916)
Sroga (1916)

RKU-8, polish river cutter laid down 1916
Displacement:
5 t light; 5 t standard; 5 t normal; 6 t full load
Dimensions: Length overall / water x beam x draught
31,39 ft / 30,91 ft x 8,04 ft x 1,48 ft (normal load)
9,57 m / 9,42 m x 2,45 m x 0,45 m
Armament:
1 - 0,30" / 7,6 mm guns in single mounts, 0,01lbs / 0,00kg shells, 1908 Model
Breech loading gun in a deck mount with hoist
on centreline forward
Weight of broadside 0 lbs / 0 kg
Shells per gun, main battery: 3 000
Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 0,39" / 10 mm 21,95 ft / 6,69 m 1,51 ft / 0,46 m
Ends: Unarmoured
Main Belt covers 109% of normal length
Main belt does not fully cover magazines and engineering spaces
Machinery:
Petrol Internal combustion motors,
Direct drive, 1 shaft, 75 shp / 56 Kw = 12,00 kts
Range 400nm at 8,00 kts
Bunker at max displacement = 1 tons
Complement:
3
Cost:
£0,001 million / $0,003 million
Distribution of weights at normal displacement:
Armament: 0 tons, 0,0%
Armour: 1 tons, 11,7%
- Belts: 1 tons, 10,7%
- Torpedo bulkhead: 0 tons, 0,0%
- Armament: 0 tons, 1,0%
- Armour Deck: 0 tons, 0,0%
- Conning Tower: 0 tons, 0,0%
Machinery: 2 tons, 45,6%
Hull, fittings & equipment: 2 tons, 35,0%
Fuel, ammunition & stores: 0 tons, 7,7%
Miscellaneous weights: 0 tons, 0,0%
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
4 lbs / 2 Kg = 303,6 x 0,3 " / 8 mm shells or 0,0 torpedoes
Stability (Unstable if below 1.00): 1,74
Metacentric height 0,3 ft / 0,1 m
Roll period: 6,4 seconds
Steadiness - As gun platform (Average = 50 %): 8 %
- Recoil effect (Restricted arc if above 1.00): 0,00
Seaboat quality (Average = 1.00): 0,02
Hull form characteristics:
Hull has a flush deck
Block coefficient: 0,517
Length to Beam Ratio: 3,84 : 1
'Natural speed' for length: 5,56 kts
Power going to wave formation at top speed: 83 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 13,00 degrees
Stern overhang: 0,00 ft / 0,00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 2,10 ft / 0,64 m
- Forecastle (20%): 2,00 ft / 0,61 m
- Mid (50%): 1,51 ft / 0,46 m
- Quarterdeck (15%): 2,00 ft / 0,61 m
- Stern: 2,00 ft / 0,61 m
- Average freeboard: 1,85 ft / 0,56 m
Ship tends to be wet forward
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 148,2%
- Above water (accommodation/working, high = better): 54,2%
Waterplane Area: 162 Square feet or 15 Square metres
Displacement factor (Displacement / loading): 87%
Structure weight / hull surface area: 9 lbs/sq ft or 43 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,90
- Longitudinal: 3,34
- Overall: 1,02
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is cramped
Ship has quick, lively roll, not a steady gun platform
Caution: Lacks seaworthiness - very limited seakeeping ability
RKU-8 (1916)
RKU-9 (1916)
RKU-10 (1916)
RKU-11 (1916)
RKU-12 (1916)
RKU-13 (1916)
RKU-14 (1916)
RKU-15 (1917)
RKU-16 (1917)
RKU-17 (1917)
RKU-18 (1917)
RKU-19 (1917)
RKU-20 (1917)