Minesweepers/frigates, reclassified as patrol boats.
7 bought
Note: One gun usually removed during peacetime.
Maple class, Mexico (ex-SAE) Frigate laid down 1918
Displacement:
473 t light; 497 t standard; 629 t normal; 735 t full load
Dimensions: Length overall / water x beam x draught
182.00 ft / 182.00 ft x 24.60 ft x 8.20 ft (normal load)
55.47 m / 55.47 m x 7.50 m x 2.50 m
Armament:
2 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1932 Model
Breech loading guns in deck mounts
on centreline ends, evenly spread
2 - 1.57" / 40.0 mm guns (1x2 guns), 1.95lbs / 0.89kg shells, 1918 Model
Anti-aircraft guns in deck mount
on centreline amidships
4 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1918 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 130 lbs / 59 kg
Shells per gun, main battery: 150
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.00" / 25 mm - -
2nd: 0.50" / 13 mm - -
Machinery:
Coal fired boilers, complex reciprocating steam engines,
Direct drive, 2 shafts, 1,609 ihp / 1,200 Kw = 15.91 kts
Range 6,500nm at 10.00 kts
Bunker at max displacement = 239 tons (100% coal)
Complement:
62 - 81
Cost:
£0.090 million / $0.359 million
Distribution of weights at normal displacement:
Armament: 16 tons, 2.6 %
Armour: 6 tons, 0.9 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 6 tons, 0.9 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 104 tons, 16.6 %
Hull, fittings & equipment: 296 tons, 47.1 %
Fuel, ammunition & stores: 156 tons, 24.8 %
Miscellaneous weights: 50 tons, 7.9 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,019 lbs / 462 Kg = 16.3 x 5.0 " / 127 mm shells or 0.6 torpedoes
Stability (Unstable if below 1.00): 1.24
Metacentric height 0.9 ft / 0.3 m
Roll period: 10.9 seconds
Steadiness - As gun platform (Average = 50 %): 72 %
- Recoil effect (Restricted arc if above 1.00): 0.29
Seaboat quality (Average = 1.00): 1.76
Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.600
Length to Beam Ratio: 7.40 : 1
'Natural speed' for length: 13.49 kts
Power going to wave formation at top speed: 56 %
Trim (Max stability = 0, Max steadiness = 100): 41
Bow angle (Positive = bow angles forward): 0.00 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 (20 %): 9.50 ft / 2.90 m
- Mid (50 %): 9.50 ft / 2.90 m
- Quarterdeck (15 %): 9.50 ft / 2.90 m
- Stern: 9.50 ft / 2.90 m
- Average freeboard: 9.94 ft / 3.03 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 83.0 %
- Above water (accommodation/working, high = better): 95.6 %
Waterplane Area: 3,275 Square feet or 304 Square metres
Displacement factor (Displacement / loading): 159 %
Structure weight / hull surface area: 52 lbs/sq ft or 252 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.31
- Longitudinal: 4.96
- Overall: 1.49
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