WesWorld

20 MTB-81 class (Atlantis)


18 Type 1 Motor launch (license built)


SOLD to Columbia Q3/40

4 MAS (ex-Phillipines)

SOLD to Argentina Q1/41

6 River Gunboat (RGB):
DECOMISSIONED

12 River Patrol Boat (RPB):
DECOMISSIONED

Avispa Class MTB



10 built

Displacement: 100 tons
Armament: 2x47mm, 2x20mm 4x21"TT or 10 D.C.
Machinery: 4x 1200 hp Roth-Packard liquid cooled engines
Speed: 34 knots
Cruising radius: 2000 nm
Crew: 20

G-1 class, Mexico Patrol Craft laid down 1940

Displacement:
127 t light; 131 t standard; 141 t normal; 149 t full load

Dimensions: Length overall / water x beam x draught
154.02 ft / 150.00 ft x 15.50 ft x 5.30 ft (normal load)
46.95 m / 45.72 m x 4.72 m x 1.62 m

Armament:
2 - 1.85" / 47.0 mm guns in single mounts, 3.17lbs / 1.44kg shells, 1940 Model
Dual purpose guns in deck mounts
on centreline ends, evenly spread
4 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1940 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 7 lbs / 3 kg
Shells per gun, main battery: 300

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.00" / 25 mm - -

Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 3,393 shp / 2,531 Kw = 24.10 kts
Range 2,700nm at 10.00 kts
Bunker at max displacement = 18 tons

Complement:
19 - 26

Cost:
£0.087 million / $0.347 million

Distribution of weights at normal displacement:
Armament: 1 tons, 0.6 %
Armour: 2 tons, 1.2 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 2 tons, 1.2 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 67 tons, 47.4 %
Hull, fittings & equipment: 47 tons, 33.7 %
Fuel, ammunition & stores: 14 tons, 10.0 %
Miscellaneous weights: 10 tons, 7.1 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
49 lbs / 22 Kg = 15.5 x 1.9 " / 47 mm shells or 0.1 torpedoes
Stability (Unstable if below 1.00): 1.07
Metacentric height 0.3 ft / 0.1 m
Roll period: 11.1 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.08
Seaboat quality (Average = 1.00): 1.00

Hull form characteristics:
Hull has raised forecastle
Block coefficient: 0.400
Length to Beam Ratio: 9.68 : 1
'Natural speed' for length: 12.25 kts
Power going to wave formation at top speed: 70 %
Trim (Max stability = 0, Max steadiness = 100): 70
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: 15.00 ft / 4.57 m
- Forecastle (14 %): 12.00 ft / 3.66 m (7.00 ft / 2.13 m aft of break)
- Mid (50 %): 7.00 ft / 2.13 m
- Quarterdeck (15 %): 7.00 ft / 2.13 m
- Stern: 7.00 ft / 2.13 m
- Average freeboard: 7.87 ft / 2.40 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 165.7 %
- Above water (accommodation/working, high = better): 100.4 %
Waterplane Area: 1,431 Square feet or 133 Square metres
Displacement factor (Displacement / loading): 71 %
Structure weight / hull surface area: 15 lbs/sq ft or 71 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.50
- Longitudinal: 3.80
- Overall: 0.61
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