Image originally by thesmilingassassin and modified by me.
SF/LF-164t, Irish Subchaser/Light Minesweeper laid down 1936
Displacement:
148 t light; 153 t standard; 164 t normal; 173 t full load
Dimensions: Length overall / water x beam x draught
145.53 ft / 134.51 ft x 19.36 ft x 5.58 ft (normal load)
44.36 m / 41.00 m x 5.90 m x 1.70 m
Armament:
1 - 1.57" / 40.0 mm guns in single mounts, 1.95lbs / 0.88kg shells, 1936 Model
Anti-aircraft gun in deck mount
on centreline forward
2 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1936 Model
Anti-aircraft guns in deck mounts
on side, all amidships
1 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1936 Model
Anti-aircraft gun in deck mount
on centreline aft
Weight of broadside 3 lbs / 1 kg
Shells per gun, main battery: 650
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.50" / 13 mm 0.50" / 13 mm -
2nd: 0.50" / 13 mm - -
- Conning tower: 0.50" / 13 mm
Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 1,514 shp / 1,129 Kw = 19.00 kts
Range 2,500nm at 10.00 kts
Bunker at max displacement = 19 tons
Complement:
22 - 29
Cost:
£0.060 million / $0.241 million
Distribution of weights at normal displacement:
Armament: 0 tons, 0.2 %
Armour: 1 tons, 0.6 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 1 tons, 0.4 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.2 %
Machinery: 42 tons, 25.9 %
Hull, fittings & equipment: 85 tons, 51.7 %
Fuel, ammunition & stores: 15 tons, 9.4 %
Miscellaneous weights: 20 tons, 12.2 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
310 lbs / 141 Kg = 158.8 x 1.6 " / 40 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.11
Metacentric height 0.5 ft / 0.2 m
Roll period: 11.3 seconds
Steadiness - As gun platform (Average = 50 %): 55 %
- Recoil effect (Restricted arc if above 1.00): 0.02
Seaboat quality (Average = 1.00): 1.63
Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.395
Length to Beam Ratio: 6.95 : 1
'Natural speed' for length: 11.60 kts
Power going to wave formation at top speed: 66 %
Trim (Max stability = 0, Max steadiness = 100): 34
Bow angle (Positive = bow angles forward): 40.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 13.12 ft / 4.00 m
- Forecastle (20 %): 11.48 ft / 3.50 m
- Mid (50 %): 9.02 ft / 2.75 m
- Quarterdeck (15 %): 8.20 ft / 2.50 m
- Stern: 8.20 ft / 2.50 m
- Average freeboard: 9.75 ft / 2.97 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 100.1 %
- Above water (accommodation/working, high = better): 129.7 %
Waterplane Area: 1,598 Square feet or 148 Square metres
Displacement factor (Displacement / loading): 151 %
Structure weight / hull surface area: 24 lbs/sq ft or 118 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.77
- Longitudinal: 10.01
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Excellent seaboat, comfortable, can fire her guns in the heaviest weather
Breakdown of Weights:
-20t for depth charges (LF-class)
-20t for minesweeping gear (SF-class)
Vessels in class:
In Minesweeper configuration
- LÉ
Aisling (SF-1) (sold to Britain 1941)
- LÉ
Emer (SF-2) (sold to Britain 1941)
- LÉ
Fola (SF-3) (sold to Britain 1941)
- LÉ
Banba (SF-4) (sold to Britain 1941)
- LÉ
Maeve (SF-5) (sold to Britain 1941)
- LÉ
Cliona (SF-6) (sold to Britain 1941)
- LÉ
Fand (SF-7) (sold to Britain 1941)
- LÉ
Ness (SF-8) (sold to Britain 1941)
In Subchaser configuration
- LÉ
Orla (LF-1)
- LÉ
Etain (LF-2)
- LÉ
Macha (LF-3)
- LÉ
Achall (LF-4)
- LÉ
Roisin (LF-5)
- LÉ
Scathach (LF-6)
- LÉ
Uathach (LF-7)
- LÉ
Ciara (LF-8)
Notes and Comments:
The
Aisling-class minesweepers are small minesweepers designed for use in shallow coastal conditions. The ships are designed to be easily converted to serve as submarine chasers, depending upon the needs of the Naval Service.