WesWorld

Just having fun with small(er) vessels. Basically, a ship made for the North Atlantic, checking to make sure everyone's trawlers are playing fair. During wartime, a bit of a minelayer or an ASW ship. Based on the Black Swan-class sloop. She's a bit heavy for what she is supposed to do, I think, but it's a bit of a tradeoff to get a nice seaboat rating. The way I see it, you deserve at least one creature comfort if you go mucking about chasing trawlers up in the northern seas... plus there's room for adding weight during wartime. Theoretically...

Deirdre, Republic of Ireland Fisheries Patrol Vessel laid down 1935

1,327 t light; 1,379 t standard; 1,596 t normal; 1,770 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(298.55 ft / 290.00 ft) x 39.00 ft x (13.00 / 13.89 ft)
(91.00 m / 88.39 m) x 11.89 m x (3.96 / 4.23 m)

Armament:
4 - 4.00" / 102 mm 50.0 cal guns - 33.88lbs / 15.37kg shells, 70 per gun
Dual purpose guns in deck and hoist mounts, 1935 Model
4 x Single mounts on centreline ends, evenly spread
2 raised mounts - superfiring
6 - 1.57" / 40.0 mm 45.0 cal guns - 1.97lbs / 0.89kg shells, 500 per gun
Quick firing guns in deck and hoist mounts, 1935 Model
2 x Twin mounts on side ends, majority forward
1 x Twin mount on centreline amidships (forward deck)
6 - 0.79" / 20.0 mm 45.0 cal guns - 0.25lbs / 0.11kg shells, 1,500 per gun
Quick firing guns in deck mounts, 1935 Model
6 x Single mounts on sides, evenly spread
Weight of broadside 149 lbs / 67 kg
8 - 21.0" / 533 mm, 19.00 ft / 5.79 m torpedoes - 1.304 t each, 10.430 t total
In 2 sets of deck mounted centre rotating tubes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 1.50" / 38 mm 250.00 ft / 76.20 m 8.05 ft / 2.45 m
Ends: Unarmoured
Main Belt covers 133 % of normal length

- Torpedo Bulkhead:
1.00" / 25 mm 137.50 ft / 41.91 m 8.59 ft / 2.62 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 2.50" / 64 mm 1.00" / 25 mm 1.00" / 25 mm
2nd: 0.50" / 13 mm 0.50" / 13 mm 0.50" / 13 mm
3rd: 0.50" / 13 mm 0.50" / 13 mm -

- Armoured deck - multiple decks: 0.50" / 13 mm For and Aft decks

- Conning towers: Forward 2.00" / 51 mm, Aft 0.00" / 0 mm

Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 7,856 shp / 5,861 Kw = 22.00 kts
Range 9,000nm at 12.00 kts
Bunker at max displacement = 391 tons

Complement:
126 - 164

Cost:
£0.478 million / $1.913 million

Distribution of weights at normal displacement:
Armament: 59 tons, 3.7 %
- Guns: 48 tons, 3.0 %
- Torpedoes: 10 tons, 0.7 %
Armour: 286 tons, 17.9 %
- Belts: 120 tons, 7.5 %
- Torpedo bulkhead: 44 tons, 2.7 %
- Armament: 70 tons, 4.4 %
- Armour Deck: 46 tons, 2.9 %
- Conning Tower: 6 tons, 0.4 %
Machinery: 223 tons, 14.0 %
Hull, fittings & equipment: 674 tons, 42.2 %
Fuel, ammunition & stores: 269 tons, 16.9 %
Miscellaneous weights: 85 tons, 5.3 %
- Hull above water: 15 tons
- On freeboard deck: 45 tons
- Above deck: 25 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
3,756 lbs / 1,704 Kg = 117.4 x 4.0 " / 102 mm shells or 1.6 torpedoes
Stability (Unstable if below 1.00): 1.16
Metacentric height 1.6 ft / 0.5 m
Roll period: 12.9 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.17
Seaboat quality (Average = 1.00): 1.40

Hull form characteristics:
Hull has a flush deck,
a normal bow and a cruiser stern
Block coefficient (normal/deep): 0.380 / 0.394
Length to Beam Ratio: 7.44 : 1
'Natural speed' for length: 17.03 kts
Power going to wave formation at top speed: 53 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 2.00 ft / 0.61 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 30.00 %, 18.00 ft / 5.49 m, 12.00 ft / 3.66 m
- Forward deck: 30.00 %, 12.00 ft / 3.66 m, 12.00 ft / 3.66 m
- Aft deck: 25.00 %, 12.00 ft / 3.66 m, 12.00 ft / 3.66 m
- Quarter deck: 15.00 %, 12.00 ft / 3.66 m, 12.00 ft / 3.66 m
- Average freeboard: 12.72 ft / 3.88 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 116.3 %
- Above water (accommodation/working, high = better): 95.2 %
Waterplane Area: 6,870 Square feet or 638 Square metres
Displacement factor (Displacement / loading): 164 %
Structure weight / hull surface area: 63 lbs/sq ft or 308 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.00
- Longitudinal: 2.57
- Overall: 1.10
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
Good seaboat, rides out heavy weather easily

Decent size, moderate arms. Basically a slow destroyer with armor. I have some like that

Length is likely long enough for the wave period, not sure. I know around 70m was too short, while 90m was enough, just don't know what the minimum was.

The armor- both belt and deck are in line with the protection of the USS...Somers class I think. Anti-strafing, light splinters. Not unreasonable for a dual use.

The TDS, I'd really suggest scrapping. Right now you have a "Cramped" rating for machinery. As I recall, Springsharp is likely removing about 13ft of usable beam for the internal bulges of the TDS. The trade off is likely not worth the minimal protection the TDS offers.

Block coefficient- 0.38 is the minimum allowed, and you're there. Do you need to be? I've got the impression that long fine hulls can be less effective as sea boats (despite SS's text), particularly at slower speeds and for turns- both of which may matter.

Freeboard - I'd suggest bringing the forepart of the vessel up by a deck level, to 20ft, along with the stem.

Leaving the reserve strength is a bonus on such a vessel.

Okay, here's what I've got now. A 20ft forecastle, and the TDS removed. It definitely made a difference to the cramped engine spaces! Seakeeping and steadiness also went through the roof compared to the earlier design. I did look at the rules regarding block coefficient when I designed her - she was actually a slight bit smaller until I changed the BC.

Deirdre, Republic of Ireland Fisheries Patrol Vessel laid down 1935

Displacement:
1,327 t light; 1,379 t standard; 1,596 t normal; 1,770 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(299.28 ft / 290.00 ft) x 39.00 ft x (13.00 / 13.89 ft)
(91.22 m / 88.39 m) x 11.89 m x (3.96 / 4.23 m)

Armament:
4 - 4.00" / 102 mm 50.0 cal guns - 33.88lbs / 15.37kg shells, 70 per gun
Dual purpose guns in deck and hoist mounts, 1935 Model
4 x Single mounts on centreline ends, evenly spread
2 raised mounts - superfiring
6 - 1.57" / 40.0 mm 45.0 cal guns - 1.97lbs / 0.89kg shells, 500 per gun
Quick firing guns in deck and hoist mounts, 1935 Model
2 x Twin mounts on sides forward
1 x Twin mount on centreline amidships (forward deck)
6 - 0.79" / 20.0 mm 45.0 cal guns - 0.25lbs / 0.11kg shells, 1,500 per gun
Quick firing guns in deck mounts, 1935 Model
6 x Single mounts on sides, evenly spread
Weight of broadside 149 lbs / 68 kg
8 - 21.0" / 533 mm, 19.00 ft / 5.79 m torpedoes - 1.304 t each, 10.430 t total
In 2 sets of deck mounted centre rotating tubes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 1.50" / 38 mm 250.00 ft / 76.20 m 8.05 ft / 2.45 m
Ends: Unarmoured
Main Belt covers 133 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 2.50" / 64 mm 1.00" / 25 mm 1.00" / 25 mm
2nd: 0.50" / 13 mm 0.50" / 13 mm 0.50" / 13 mm
3rd: 0.50" / 13 mm 0.50" / 13 mm -

- Armoured deck - multiple decks: 0.50" / 13 mm For and Aft decks

- Conning towers: Forward 2.00" / 51 mm, Aft 0.00" / 0 mm

Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 7,856 shp / 5,861 Kw = 22.00 kts
Range 9,000nm at 12.00 kts
Bunker at max displacement = 391 tons

Complement:
126 - 164

Cost:
£0.478 million / $1.913 million

Distribution of weights at normal displacement:
Armament: 59 tons, 3.7 %
- Guns: 48 tons, 3.0 %
- Torpedoes: 10 tons, 0.7 %
Armour: 242 tons, 15.2 %
- Belts: 120 tons, 7.5 %
- Armament: 70 tons, 4.4 %
- Armour Deck: 46 tons, 2.9 %
- Conning Tower: 6 tons, 0.4 %
Machinery: 223 tons, 14.0 %
Hull, fittings & equipment: 718 tons, 45.0 %
Fuel, ammunition & stores: 269 tons, 16.9 %
Miscellaneous weights: 85 tons, 5.3 %
- Hull above water: 15 tons
- On freeboard deck: 45 tons
- Above deck: 25 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
3,861 lbs / 1,751 Kg = 120.7 x 4.0 " / 102 mm shells or 1.6 torpedoes
Stability (Unstable if below 1.00): 1.16
Metacentric height 1.6 ft / 0.5 m
Roll period: 12.9 seconds
Steadiness - As gun platform (Average = 50 %): 76 %
- Recoil effect (Restricted arc if above 1.00): 0.18
Seaboat quality (Average = 1.00): 1.85

Hull form characteristics:
Hull has raised forecastle,
a normal bow and a cruiser stern
Block coefficient (normal/deep): 0.380 / 0.394
Length to Beam Ratio: 7.44 : 1
'Natural speed' for length: 17.03 kts
Power going to wave formation at top speed: 53 %
Trim (Max stability = 0, Max steadiness = 100): 41
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 2.00 ft / 0.61 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 30.00 %, 20.00 ft / 6.10 m, 20.00 ft / 6.10 m
- Forward deck: 30.00 %, 14.00 ft / 4.27 m, 12.00 ft / 3.66 m
- Aft deck: 25.00 %, 12.00 ft / 3.66 m, 12.00 ft / 3.66 m
- Quarter deck: 15.00 %, 12.00 ft / 3.66 m, 12.00 ft / 3.66 m
- Average freeboard: 14.70 ft / 4.48 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 56.6 %
- Above water (accommodation/working, high = better): 99.5 %
Waterplane Area: 6,870 Square feet or 638 Square metres
Displacement factor (Displacement / loading): 172 %
Structure weight / hull surface area: 61 lbs/sq ft or 300 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.97
- Longitudinal: 3.88
- Overall: 1.11
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

I think that looks closer to your design goal. Nice to see poor neglected Eire get a ship. Erin go bragh! I should know how to spell that... but I don't.

Now we'll see what others have to say about the ship

The fun thing is- look at the survivability and #torpedoes the two designs can take... virtually identical.