WesWorld

...are introducing anti-submarine mortars a mere eleven years ahead of historical, I gather?

Huh? Standard practise is to use a 5 charge pattern.

1. 1 DC rolls off the stern
2. 1. DC is fired from the projector on each beam + 1 rolled off the stern
3. 1 more rolled off the stern.

For a pattern like this, hopefully bracketing the submarine.

------X------
-------------
X-----X-----X
-------------
------X-----

Projector like these are in common usage at this time.



Unless you mean something else.

So this doesn't ring a bell, then?



Vespa Class, Corvetta Cacciasommergibili

Ships in Class ; Vespa, Maggiolino, Lucciola, Libellula

Vespa, Italian Frigate laid down 1930

Displacement:
1,000 t light; 1,065 t standard; 1,453 t normal; 1,763 t full load

Dimensions: Length overall / water x beam x draught
272.91 ft / 262.47 ft x 32.81 ft x 9.84 ft (normal load)
83.18 m / 80.00 m x 10.00 m x 3.00 m

Armament:
4 - 100mm / 47 guns (2x2 guns), 33.07lbs / 15.00kg shells, 1930 Model
Anti-aircraft guns in deck mounts
on centreline ends, evenly spread
10 - 0.98" / 25.0 mm guns ( 10 mounts), 0.52lbs / 0.24kg shells, 1930 Model
Anti-aircraft guns in deck mounts
on side, all amidships
Weight of broadside 139 lbs / 63 kg
Shells per gun, main battery: 450

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 0.79" / 20 mm 0.39" / 10 mm -
2nd: 0.39" / 10 mm - -

- Conning tower: 0.79" / 20 mm

Machinery:
Oil fired boilers, steam turbines plus batteries,
Electric motors, 2 shafts, 6,000 shp / 4,476 Kw = 20.16 kts ( Electric "creeping" motors)
Range 3,850nm at 20.00 kts
Bunker at max displacement = 698 tons

Complement:
116 - 152

Cost:
£0.309 million / $1.236 million

Distribution of weights at normal displacement:
Armament: 16 tons, 1.1 %
Armour: 8 tons, 0.6 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 6 tons, 0.4 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 2 tons, 0.1 %
Machinery: 182 tons, 12.5 %
Hull, fittings & equipment: 724 tons, 49.8 %
Fuel, ammunition & stores: 453 tons, 31.2 %
Miscellaneous weights: 70 tons, 4.8 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
4,267 lbs / 1,936 Kg = 139.9 x 3.9 " / 100 mm shells or 1.5 torpedoes
Stability (Unstable if below 1.00): 1.23
Metacentric height 1.4 ft / 0.4 m
Roll period: 11.7 seconds
Steadiness - As gun platform (Average = 50 %): 76 %
- Recoil effect (Restricted arc if above 1.00): 0.18
Seaboat quality (Average = 1.00): 1.95

Hull form characteristics:
Hull has low quarterdeck
Block coefficient: 0.600
Length to Beam Ratio: 8.00 : 1
'Natural speed' for length: 16.20 kts
Power going to wave formation at top speed: 57 %
Trim (Max stability = 0, Max steadiness = 100): 39
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 19.69 ft / 6.00 m
- Forecastle (20 %): 16.40 ft / 5.00 m
- Mid (50 %): 16.40 ft / 5.00 m
- Quarterdeck (25 %): 8.20 ft / 2.50 m (16.40 ft / 5.00 m before break)
- Stern: 8.20 ft / 2.50 m
- Average freeboard: 14.62 ft / 4.46 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 57.3 %
- Above water (accommodation/working, high = better): 169.6 %
Waterplane Area: 6,298 Square feet or 585 Square metres
Displacement factor (Displacement / loading): 255 %
Structure weight / hull surface area: 62 lbs/sq ft or 303 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.16
- Longitudinal: 5.31
- Overall: 1.35
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

10 tons for 10x25mm single mounts

8 tons for 8x25mm single mounts
40 tons for main ASW weapon
20tons for towed torpedoes + depth charges

Its not you think it is. I'll have to explain in my next news update. 1930 ship as well.

I'll point out that with the historical Italian sonar and weapons, the RN reckoned that a submarine faced a 12.5% chance of being destroyed if it came near a convoy. The Med. is awful for subs, especially large ones.