WesWorld

Musings on the Italian Navy's new construction and refits.

First up, a few subs.

The V-Class is a test of a H2O2 drive. There would be a small number constructed for testing. Unarmed.
Date 1945
Coastal
Armament: None
H2O2HP 100
DieselHP 400
CREW 13
Misc Weight 100 (representative of additional safety measures put in place for the H2O2 systems and other non-standard equipment relating to H2O2)
wt fuel&batts 30
Light weight 241
kerb wt 271
disp 320
res buoyancy 15%
Max Surf Spd 10.7knts
Max Sub Spd 6.7knts

L: 40m
Beam: 4m
D: 4m
Crush depth 225
#TT 0
Tons: Oil 20
Tons H2O2: 10

Surface Range: 3063@10knts
Underwater range: 1375@4knts


The X-Class. Designed to be the standard Oceanic boat going forward, it features a underwater speed almost as fast as its surface speed and is designed for prolonged underwater operation. Equipped with a Snorkel.
Date 1945
Oceanic
Armament: 2x 25 in hydrodynamic mounting
ElecHP 3000
DieselHP 3600
CREW 43
Misc weight 20 (representative of 25mm AA guns, Snorkel and radar)
wt fuel&batts 560
Light weight 1225
kerb wt 1445
disp 1775
res buoyancy 19%
Max Surf Spd 15.5knts
Max Sub Spd 14.2knts

L 75.0m
Beam 8.6m
D 5.5m
Crush depth 317.5
#TT 6 x 533mm (6 bow)
Mines 20 (used to sim reload torps)
Tons Oil 200.0
Tons Battery 360.0

Surface Range 10350@10knts
Underwater range 715@4knts


The Y-Class is meant to be the coastal analog of the X-Class. Hull based on the V-Class Small subs still have a place in the Med. Equipped with a Snorkel.
Date 1945
Coastal
Armament 1x 25 in hydrodynamic mount
ElecHP 600
DieselHP 400
CREW 14
Misc Weight 15 (representative of 25mm AA gun, Snorkel and radar)
wt fuel&batts 70
Light weight 227
kerb wt 271
disp 320
res buoyancy 15%
Max Surf Spd 10.7knts
Max Sub Spd 12.2knts

L 40m
Beam 4m
D 4m
Crush depth 225
#TT 4 x 533mm (4 bow)
Mines 4 (used to sim reload torps)
Tons Oil 40.0
Tons Battery 30.0

Surface Range 6125@10knts
Underwater range 177@4knts

Quoted from "snip"

The V-Class is a test of a H2O2 drive. There would be a small number constructed for testing. Unarmed.

Good idea to build multiple test vessels. That way when one catches fire / blows up and sinks, you have spares! :D

Quoted from "Brockpaine"

Quoted from "snip"

The V-Class is a test of a H2O2 drive. There would be a small number constructed for testing. Unarmed.

Good idea to build multiple test vessels. That way when one catches fire / blows up and sinks, you have spares!

Indeed

I guess that the Italian Navy has enough guinea pigs sailors who are stupid brave enough to board those subs...

They should be the X-class, not the V-class, so you could name them Exploder and Excrutiator. ;)

As an aside... out of curiosity... I simmed the X-class and I can't make my Subsim arrive at all of the same figures you're posting. The weights for all of the systems seem to be off somewhere - my sim is coming out eighty tons heavier across the board, even though I've got all the same figures inputted that you've stated. Would you double-check that you've posted all the specs correctly?

This should do, I will look and see what I messed up in transcribing.


EDIT: Looks like I missed the "mines" (reload torps) and misc, weight. Adding those into the OP.

Okay, I sorted it out. Instead of entering 2.5 into the Gun Caliber box, you put in 20 tons into miscellaneous weight and left gun caliber empty. That changes things quite a bit.

In the future, perhaps note what figure you're using for miscellaneous weight, and perhaps add a note explaining when it stands for something like deck guns. Because I didn't understand how you were simming them, I did it a different way than you did and thus arrived at a different conclusion. :)

I added some notes into the OP, does that clarify what I did?

Yes, it means I can replicate the sim on my own.

The first big project of the year, a major refit of Duca degli Abruzzi and Duca d'Aosta. The highlights: Improvements to the 152mm battery & increase in the ammunition count by 200 rounds. Replacement of the 47mm AA battery with modern 76mm and 37mm weaponry. Removal of torpedo and associated protection systems. Addition of modern electronics. General refurbishment. Cost: 1990.5t per ship. Time: 4.24 months (two quarters).

Duca degli Abruzzi (Refit), Italian Cruiser laid down 1934

Displacement:
7,962 t light; 8,398 t standard; 9,777 t normal; 10,880 t full load

Dimensions: Length overall / water x beam x draught
579.02 ft / 557.74 ft x 65.62 ft x 18.70 ft (normal load)
176.48 m / 170.00 m x 20.00 m x 5.70 m

Armament:
8 - 5.98" / 152 mm guns (4x2 guns), 99.21lbs / 45.00kg shells, 1934 Model
Dual purpose guns in turrets (on barbettes)
on centreline ends, evenly spread
12 - 2.99" / 76.0 mm guns (6x2 guns), 14.86lbs / 6.74kg shells, 1945 Model
Breech loading guns in deck mounts with hoists
on side, all amidships
16 - 1.46" / 37.0 mm guns (4x4 guns), 1.55lbs / 0.70kg shells, 1945 Model
Breech loading guns in deck mounts
on side, evenly spread
12 - 0.98" / 25.0 mm guns (6x2 guns), 0.48lbs / 0.22kg shells, 1934 Model
Breech loading guns in deck mounts
on side, evenly spread
Weight of broadside 1,002 lbs / 455 kg
Shells per gun, main battery: 400

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 3.94" / 100 mm 328.08 ft / 100.00 m 10.47 ft / 3.19 m
Ends: Unarmoured
Main Belt covers 90 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 5.31" / 135 mm 2.76" / 70 mm 3.94" / 100 mm
2nd: 1.18" / 30 mm 0.79" / 20 mm 0.79" / 20 mm
3rd: 0.39" / 10 mm - -
4th: 0.39" / 10 mm - -

- Armour deck: 2.36" / 60 mm, Conning tower: 5.31" / 135 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 66,000 shp / 49,236 Kw = 31.02 kts
Range 3,500nm at 25.00 kts
Bunker at max displacement = 2,482 tons

Complement:
491 - 639

Cost:
£3.213 million / $12.853 million

Distribution of weights at normal displacement:
Armament: 131 tons, 1.3 %
Armour: 2,033 tons, 20.8 %
- Belts: 581 tons, 5.9 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 291 tons, 3.0 %
- Armour Deck: 1,108 tons, 11.3 %
- Conning Tower: 52 tons, 0.5 %
Machinery: 1,899 tons, 19.4 %
Hull, fittings & equipment: 3,574 tons, 36.6 %
Fuel, ammunition & stores: 1,815 tons, 18.6 %
Miscellaneous weights: 325 tons, 3.3 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
15,814 lbs / 7,173 Kg = 147.6 x 6.0 " / 152 mm shells or 2.2 torpedoes
Stability (Unstable if below 1.00): 1.16
Metacentric height 3.5 ft / 1.1 m
Roll period: 14.7 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.20
Seaboat quality (Average = 1.00): 1.06

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.500
Length to Beam Ratio: 8.50 : 1
'Natural speed' for length: 27.31 kts
Power going to wave formation at top speed: 58 %
Trim (Max stability = 0, Max steadiness = 100): 67
Bow angle (Positive = bow angles forward): 30.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 31.17 ft / 9.50 m
- Forecastle (26 %): 21.33 ft / 6.50 m
- Mid (60 %): 21.33 ft / 6.50 m (13.12 ft / 4.00 m aft of break)
- Quarterdeck (25 %): 13.12 ft / 4.00 m
- Stern: 13.12 ft / 4.00 m
- Average freeboard: 19.07 ft / 5.81 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 79.4 %
- Above water (accommodation/working, high = better): 185.1 %
Waterplane Area: 25,357 Square feet or 2,356 Square metres
Displacement factor (Displacement / loading): 136 %
Structure weight / hull surface area: 97 lbs/sq ft or 473 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.96
- Longitudinal: 1.34
- Overall: 1.00
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

50t RaA.6 Air Search radar
20t RaA.5 Air Search radar
20t RaS.4 Surface Search radar
30t 2 x GDR1R FC Systems
30t 6 x GDR5 FC Systems
40t Improved 152mm mountings (5t per gun)
50t Improved AA mountings
45t Enhanced Command Facilities
15t Emergency Diesel
5t Construction Reserve

Thoughts?

To my thinking, addition of ammunition for the main battery requires a magazine alteration.

Quoted from "The Rock Doctor"

To my thinking, addition of ammunition for the main battery requires a magazine alteration.

I cannot seem to find a reference to magazine alteration in the current refit rules[1]. As such, I presumed that this increase was covered under the "Alterations to guns of 66mm-195mm not involving barbette alteration" clause, seeing as the barbettes themselves are not being changed.

[1] I know Navalism has a section regarding enlargement of magazines, perhaps we are thinking of that rule.

I assume the magazine is inside the barbette, which would not have any void space for the magazine to expand into. If that assumption is wrong, then fine.

Quoted from "The Rock Doctor"

I assume the magazine is inside the barbette, which would not have any void space for the magazine to expand into. If that assumption is wrong, then fine.

I found this GIF illustrating the fireing process for a 15"/42 Mk 1. One of a few source pages for the image.


Given the description found here which gives the blue-tinted section as the revolving mass, it seems to me that the revolving mass of the turret does not contain any, or at lest the majority of, the main gun shells.

Consider me corrected, then.

Quoted from "The Rock Doctor"

Consider me corrected, then.

I too thought there was provision in our refit rules for changes to magazines, but there is none in the current revision. Was there one at some point in time? Perhaps the older hands would recall...

Quoted from "BruceDuncan"

Quoted from "The Rock Doctor"

Consider me corrected, then.

I too thought there was provision in our refit rules for changes to magazines, but there is none in the current revision. Was there one at some point in time? Perhaps the older hands would recall...

For the record, I have altered the 152mm ammo counts on the two previously refitted classes, but, those were both Partial Reconstructions (50%) because they needed new engines to free up weight to be used elsewhere. The Abruzzi and sister do not need new engines to achieve the goals of the refit unlike the previous classes, so I did not feel it necessary to give them anything more then a Major Refit (25%).

I don't recall there ever being a written rule about increasing magazine capacity - even doubling it - but I do remember several years ago that a few players were browbeaten into reducing magazine capacity on the basis of refit level. Since then I've been pretty sensitive to that when adopting my own refit schemes, but since this is the first time it's come up recently, I'd been getting a little more liberal on that count.