Avisos, Sloops, and Escorts

[The Rock Doctor]

Definition

Small, ocean-going warships with deck/hoist-served weapons of 152mm and below.  Not armored.

Nomenclature

Initially, named for Belgian cities and towns, except where those names overlap with provinces.

[The Rock Doctor]

Ghent Class Aviso

Basic oceangoing sloops laid down in Britain on behalf of Belgium.  As the first Belgian warships, they were involved in the blockade of Monrovia; Charleroi was lightly damaged in a battle with a Liberian blockade-runner that sparked the brief Belgian/Liberian War of 1898.

The sloops include miscellaneous weight for passengers and cargo; this allows rapid movement of small amounts of personnel and freight outside scheduled service to Liberia or the Congo Free State.  In emergencies, it also allows dedicated boarding parties to be carried aboard for extended periods.

Ghent, laid down 1895
Leuven, laid down 1895
Charleroi, laid down 1896

Flight 1 Sloop, laid down 1895

Displacement:
   1,006 t light; 1,046 t standard; 1,308 t normal; 1,517 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (262.47 ft / 262.47 ft) x 39.37 ft x (9.84 / 10.95 ft)
   (80.00 m / 80.00 m) x 12.00 m  x (3.00 / 3.34 m)

Armament:
      2 - 4.02" / 102 mm 45.0 cal guns - 32.65lbs / 14.81kg shells, 250 per gun
     Breech loading guns in deck mounts, 1895 Model
     2 x Single mounts on centreline ends, evenly spread
      4 - 2.24" / 57.0 mm 45.0 cal guns - 5.71lbs / 2.59kg shells, 350 per gun
     Quick firing guns in deck mounts, 1895 Model
     4 x Single mounts on sides, evenly spread
      4 - 0.31" / 8.0 mm 45.0 cal guns - 0.02lbs / 0.01kg shells, 15,000 per gun
     Machine guns in deck mounts, 1895 Model
     4 x Single mounts on sides, evenly spread
      Weight of broadside 88 lbs / 40 kg
      Main Torpedoes
      1 - 16.0" / 406 mm, 13.12 ft / 4.00 m torpedo - 0.324 t total
   In a deck mounted carriage/fixed tube

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.97" / 50 mm   0.98" / 25 mm            -
   2nd:   0.98" / 25 mm         -               -

Machinery:
   Coal fired boilers, complex reciprocating steam engines,
   Direct drive, 2 shafts, 2,000 ihp / 1,492 Kw = 15.62 kts
   Range 6,000nm at 10.00 kts
   Bunker at max displacement = 471 tons (100% coal)

Complement:
   108 - 141

Cost:
   £0.087 million / $0.348 million

Distribution of weights at normal displacement:
   Armament: 15 tons, 1.2 %
      - Guns: 15 tons, 1.2 %
      - Weapons: 0 tons, 0.0 %
   Armour: 22 tons, 1.7 %
      - Armament: 22 tons, 1.7 %
   Machinery: 339 tons, 25.9 %
   Hull, fittings & equipment: 495 tons, 37.9 %
   Fuel, ammunition & stores: 302 tons, 23.1 %
   Miscellaneous weights: 134 tons, 10.2 %
      - Hull above water: 134 tons
        -40 t:  Passenger/Board Party Accommodation for 20
        -60 t:  Cargo
        -34 t:  Weight Reserve / Wireless

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     2,440 lbs / 1,107 Kg = 75.4 x 4.0 " / 102 mm shells or 3.2 torpedoes
   Stability (Unstable if below 1.00): 1.67
   Metacentric height 2.9 ft / 0.9 m
   Roll period: 9.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.04
   Seaboat quality  (Average = 1.00): 2.00

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.450 / 0.469
   Length to Beam Ratio: 6.67 : 1
   'Natural speed' for length: 16.20 kts
   Power going to wave formation at top speed: 41 %
   Trim (Max stability = 0, Max steadiness = 100): 35
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: -1.64 ft / -0.50 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  13.12 ft / 4.00 m,  13.12 ft / 4.00 m
      - Forward deck:   30.00 %,  13.12 ft / 4.00 m,  13.12 ft / 4.00 m
      - Aft deck:   35.00 %,  13.12 ft / 4.00 m,  13.12 ft / 4.00 m
      - Quarter deck:   15.00 %,  13.12 ft / 4.00 m,  13.12 ft / 4.00 m
      - Average freeboard:      13.12 ft / 4.00 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 99.6 %
      - Above water (accommodation/working, high = better): 152.2 %
   Waterplane Area: 6,591 Square feet or 612 Square metres
   Displacement factor (Displacement / loading): 149 %
   Structure weight / hull surface area: 50 lbs/sq ft or 245 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.90
      - Longitudinal: 2.39
      - Overall: 1.00
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

[The Rock Doctor]

Liege Class Aviso

The Liege class is a follow-on to the Ghent class, and features only modest changes to the original design.  The class was built in Belgium, with British assistance.

Liege, laid down 1898
Hasselt, laid down 1898
Arlon, laid down 1899

Flight Two Sloop, laid down 1898

Displacement:
   979 t light; 1,019 t standard; 1,308 t normal; 1,539 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (262.47 ft / 262.47 ft) x 39.37 ft x (9.84 / 11.07 ft)
   (80.00 m / 80.00 m) x 12.00 m  x (3.00 / 3.37 m)

Armament:
      2 - 4.02" / 102 mm 45.0 cal guns - 32.65lbs / 14.81kg shells, 250 per gun
     Breech loading guns in deck mounts, 1898 Model
     2 x Single mounts on centreline ends, evenly spread
      4 - 2.24" / 57.0 mm 45.0 cal guns - 5.71lbs / 2.59kg shells, 350 per gun
     Quick firing guns in deck mounts, 1898 Model
     4 x Single mounts on sides, evenly spread
      4 - 0.31" / 8.0 mm 45.0 cal guns - 0.02lbs / 0.01kg shells, 15,000 per gun
     Machine guns in deck mounts, 1898 Model
     4 x Single mounts on sides, evenly spread
      Weight of broadside 88 lbs / 40 kg
      Main Torpedoes
      1 - 13.8" / 350 mm, 13.12 ft / 4.00 m torpedo - 0.278 t total
   In a deck mounted carriage/fixed tube

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.97" / 50 mm   0.98" / 25 mm            -
   2nd:   0.98" / 25 mm         -               -

Machinery:
   Coal fired boilers, complex reciprocating steam engines,
   Direct drive, 2 shafts, 2,000 ihp / 1,492 Kw = 15.62 kts
   Range 7,000nm at 10.00 kts
   Bunker at max displacement = 520 tons (100% coal)

Complement:
   108 - 141

Cost:
   £0.084 million / $0.335 million

Distribution of weights at normal displacement:
   Armament: 15 tons, 1.2 %
      - Guns: 15 tons, 1.2 %
      - Weapons: 0 tons, 0.0 %
   Armour: 22 tons, 1.7 %
      - Armament: 22 tons, 1.7 %
   Machinery: 323 tons, 24.7 %
   Hull, fittings & equipment: 481 tons, 36.8 %
   Fuel, ammunition & stores: 329 tons, 25.1 %
   Miscellaneous weights: 138 tons, 10.6 %
      - Hull above water: 138 tons
        -40 t:  Passenger/Board Party Accommodation for 20
        -60 t:  Cargo
        -38 t:  Weight Reserve / Wireless


Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     2,548 lbs / 1,156 Kg = 78.7 x 4.0 " / 102 mm shells or 3.9 torpedoes
   Stability (Unstable if below 1.00): 1.69
   Metacentric height 2.9 ft / 0.9 m
   Roll period: 9.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.04
   Seaboat quality  (Average = 1.00): 2.00

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.450 / 0.471
   Length to Beam Ratio: 6.67 : 1
   'Natural speed' for length: 16.20 kts
   Power going to wave formation at top speed: 41 %
   Trim (Max stability = 0, Max steadiness = 100): 35
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: -1.64 ft / -0.50 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  13.12 ft / 4.00 m,  13.12 ft / 4.00 m
      - Forward deck:   30.00 %,  13.12 ft / 4.00 m,  13.12 ft / 4.00 m
      - Aft deck:   35.00 %,  13.12 ft / 4.00 m,  13.12 ft / 4.00 m
      - Quarter deck:   15.00 %,  13.12 ft / 4.00 m,  13.12 ft / 4.00 m
      - Average freeboard:      13.12 ft / 4.00 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 96.0 %
      - Above water (accommodation/working, high = better): 152.2 %
   Waterplane Area: 6,591 Square feet or 612 Square metres
   Displacement factor (Displacement / loading): 154 %
   Structure weight / hull surface area: 49 lbs/sq ft or 238 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.90
      - Longitudinal: 2.39
      - Overall: 1.00
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather