On the training ship, she's a handy size - 1 year to build, and has slack in the build. You're right, her sisters could be escorts, hadn't considered that in the design though. As for the mixed 100mm and 125mm- purely to make sure gunnery recruits have exposure to both the standard AA mounts.
Whoa, missed that stability warning.
However, the ship had lots of room to trim down, once under 48 it was ok. 38 gives 1.07.
She was built figuring on beating underwater speeds.
...
After fiddling trying high speeds, I found switching to diesel was advisable if I was trying for the higher speeds, and if I went to 21 for +3kts, then 25kts for 0.5 comp hull beckoned. Then the vessel doubled in size, I can't figure it out
SC-1, Netherlands Subchaser laid down 1935
Displacement:
249 t light; 257 t standard; 263 t normal; 268 t full load
Dimensions: Length overall / water x beam x draught
181.94 ft / 177.17 ft x 19.69 ft x 5.74 ft (normal load)
55.46 m / 54.00 m x 6.00 m x 1.75 m
Armament:
1 - 2.95" / 75.0 mm guns in single mounts, 12.87lbs / 5.84kg shells, 1935 Model
Anti-aircraft gun in deck mount
on centreline forward
2 - 1.57" / 40.0 mm guns (1x2 guns), 1.95lbs / 0.88kg shells, 1935 Model
Anti-aircraft guns in deck mount
on centreline aft, all raised guns - superfiring
4 - 0.91" / 23.0 mm guns (2x2 guns), 0.37lbs / 0.17kg shells, 1935 Model
Anti-aircraft guns in deck mounts
on side, all amidships
4 - 0.52" / 13.2 mm guns in single mounts, 0.07lbs / 0.03kg shells, 1935 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 19 lbs / 8 kg
Shells per gun, main battery: 200
Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.39" / 10 mm - -
2nd: 0.31" / 8 mm - -
3rd: 0.31" / 8 mm - -
4th: 0.31" / 8 mm - -
- Conning tower: 0.39" / 10 mm
Machinery:
Diesel Internal combustion motors,
Geared drive, 1 shaft, 2,688 shp / 2,006 Kw = 21.00 kts
Range 1,600nm at 8.00 kts
Bunker at max displacement = 12 tons
Complement:
32 - 42
Cost:
£0.109 million / $0.435 million
Distribution of weights at normal displacement:
Armament: 2 tons, 0.9 %
Armour: 1 tons, 0.4 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 1 tons, 0.3 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.1 %
Machinery: 76 tons, 29.0 %
Hull, fittings & equipment: 122 tons, 46.4 %
Fuel, ammunition & stores: 14 tons, 5.4 %
Miscellaneous weights: 47 tons, 17.9 %
Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
251 lbs / 114 Kg = 19.5 x 3.0 " / 75 mm shells or 0.3 torpedoes
Stability (Unstable if below 1.00): 1.06
Metacentric height 0.5 ft / 0.1 m
Roll period: 11.8 seconds
Steadiness - As gun platform (Average = 50 %): 53 %
- Recoil effect (Restricted arc if above 1.00): 0.09
Seaboat quality (Average = 1.00): 1.05
Hull form characteristics:
Hull has raised forecastle
Block coefficient: 0.460
Length to Beam Ratio: 9.00 : 1
'Natural speed' for length: 13.31 kts
Power going to wave formation at top speed: 63 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 18.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 14.70 ft / 4.48 m
- Forecastle (15 %): 11.02 ft / 3.36 m (7.35 ft / 2.24 m aft of break)
- Mid (50 %): 7.35 ft / 2.24 m
- Quarterdeck (15 %): 7.35 ft / 2.24 m
- Stern: 7.35 ft / 2.24 m
- Average freeboard: 8.12 ft / 2.48 m
Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 120.8 %
- Above water (accommodation/working, high = better): 93.7 %
Waterplane Area: 2,141 Square feet or 199 Square metres
Displacement factor (Displacement / loading): 120 %
Structure weight / hull surface area: 30 lbs/sq ft or 148 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.99
- Longitudinal: 3.10
- Overall: 1.11
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is adequate
An attempt at a more worthy coastal protection vessel.
Equipped with hydrophones (10t) and depthcharges or mines (32t) there is little excess room (5t).
The ship is overbuilt, and not overly fast, but is perfectly capable of bird-dogging a submarine.
The 55m design means 2 should be buildable in a 120m slip, with 10m between