WesWorld

A Destroyer design I'm considering at the moment. The 4500ton "heavy destroyers" are really too expensive and not particularly well suited for anti-submarine work. Something smaller and cheaper is desired, preferably with extensive anti-submarine armament.

The result is a bit strange. There's a big hull for good seakeeping. Gun armament is limited to 4x135 LA. 2x2x152/53 are just too heavy for the size of ship. There's currently a twin 127/64 mounting under development, but it's going to take a while to appear. Light AA armament is emphasised with 5 quadruple 37/54 mounts in nice high positions for good arcs of fire. Same anti-submarine weapons fit as the frigates, which is about as good as can be done at the moment. 4x600mm torpedoes on the centreline for sinking big ships. Can't realistically fit another quadruple mounting in.

Sensors with the latest mark of sonar and made room for a nice air warning radar of reasonable size. Probably not going to have enough surface warning radars around to mount them on the ship, EC3 is just a bit big as well.

Range is pretty good as well, with as much fuel as can be reasonably fitted into the ship.

The major sacrifice is in powerplant and so speed in calm seas. I was thinking about a single shaft arrangement to save money and simplify things. Two boilers and a single turbine. I was also considering lifting half the diesel-electric machinery from the Gabbiano Class corvettes (2000shp) for low speed cruising and creeping. Speed isn't too bad at 31knts, as combined with the large hull and high freeboard it's still going to be one of the fastest destroyers around in a seaway. The need for speed in calm seas wasn't felt worth the couple of hundred tons extra.



laid down 1940

Displacement:
1,984 t light; 2,117 t standard; 2,485 t normal; 2,778 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(410.24 ft / 393.70 ft) x 39.37 ft x (14.76 / 15.82 ft)
(125.04 m / 120.00 m) x 12.00 m x (4.50 / 4.82 m)

Armament:
4 - 5.31" / 135 mm 45.0 cal guns - 70.55lbs / 32.00kg shells, 300 per gun
Breech loading guns in deck and hoist mounts, 1940 Model
2 x Twin mounts on centreline ends, evenly spread
20 - 1.46" / 37.0 mm 54.0 cal guns - 1.66lbs / 0.75kg shells, 2,000 per gun
Anti-air guns in deck mounts, 1940 Model
5 x Quad mounts on sides, evenly spread
5 raised mounts
Weight of broadside 315 lbs / 143 kg
4 - 23.6" / 600 mm, 0.00 ft / 0.00 m torpedoes - 0.000 t each, 0.000 t total
In 1 sets of deck mounted carriage/fixed tubes

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.18" / 30 mm 0.79" / 20 mm -
2nd: 0.79" / 20 mm 0.79" / 20 mm -

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 1 shaft, 30,000 shp / 22,380 Kw = 31.07 kts
Range 2,200nm at 25.00 kts
Bunker at max displacement = 661 tons

Complement:
175 - 228

Cost:
£1.279 million / $5.115 million

Distribution of weights at normal displacement:
Armament: 74 tons, 3.0 %
Armour: 36 tons, 1.4 %
- Armament: 36 tons, 1.4 %
Machinery: 802 tons, 32.3 %
Hull, fittings & equipment: 903 tons, 36.3 %
Fuel, ammunition & stores: 501 tons, 20.2 %
Miscellaneous weights: 169 tons, 6.8 %
- Hull below water: 15 tons
- Hull above water: 10 tons
- On freeboard deck: 69 tons
- Above deck: 75 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
2,059 lbs / 934 Kg = 27.4 x 5.3 " / 135 mm shells or 0.7 torpedoes
Stability (Unstable if below 1.00): 1.24
Metacentric height 1.8 ft / 0.6 m
Roll period: 12.2 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.29
Seaboat quality (Average = 1.00): 1.46

Hull form characteristics:
Hull has a flush deck,
a normal bow and large transom stern
Block coefficient (normal/deep): 0.380 / 0.397
Length to Beam Ratio: 10.00 : 1
'Natural speed' for length: 23.03 kts
Power going to wave formation at top speed: 60 %
Trim (Max stability = 0, Max steadiness = 100): 34
Bow angle (Positive = bow angles forward): 30.00 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20.00 %, 22.97 ft / 7.00 m, 16.40 ft / 5.00 m
- Forward deck: 30.00 %, 16.40 ft / 5.00 m, 16.40 ft / 5.00 m
- Aft deck: 35.00 %, 16.40 ft / 5.00 m, 16.40 ft / 5.00 m
- Quarter deck: 15.00 %, 16.40 ft / 5.00 m, 16.40 ft / 5.00 m
- Average freeboard: 16.93 ft / 5.16 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 120.1 %
- Above water (accommodation/working, high = better): 174.5 %
Waterplane Area: 9,775 Square feet or 908 Square metres
Displacement factor (Displacement / loading): 118 %
Structure weight / hull surface area: 49 lbs/sq ft or 240 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.66
- Longitudinal: 2.62
- Overall: 0.75
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent
Good seaboat, rides out heavy weather easily

12t = 4x600/650 torpedoes
7t = Scaricabombe
50t = 150 Depth Chargers
15t = D5 sonar
10t = Diesel Emergency Generator
55t = 18t per quadruple 37mm mount (35t already in sim)
20t = RA.1 Air Warning radar
10t = 1x GDR.101 FCS

I have to say a sing of thing to come.
A dedicated ASW warship.

edit:
Of this size

Quoted

Originally posted by Marek Gutkowski
I have to say a sing of thing to come.
A dedicated ASW warship.

Nothing wrong with that. Lots of people have made ASW warships already (though never this big).

I newer said it was wrong, in fact I totally approve of this design.

My comment was about Dedicated ASW Ships getting bigger.

Quoted

4 - 23.6" / 600 mm, 0.00 ft / 0.00 m torpedoes - 0.000 t each, 0.000 t total
In 1 sets of deck mounted carriage/fixed tubes

Seems to be a problem here...

Though the zero length messes up the deckspace calculation.

Quoted

A dedicated ASW warship.

Well, it's not a dedicated ASW ship, it's got a fairly potent anti-air armament as well. Not really enough range from the 37mm gun to give good cover to other ships though. Will have to wait a little while for the 76/62 automatic. Needs a fairly large ship to mount all the armament and get good seakeeping and range.

The torpedo weights are more than accounted for by misc. weight. Deckspace isn't a problem as they definitely fit on the drawing. In the position they are, they don't impinge on superstructure for living spaces.

This is Q1/1939....

It really should be stated, the length though, because of the affect on stability and seakeeping. I don't think any destroyer designer would put just four torpedoes on a destroyer, and hope to keep their job.

Quoted

Originally posted by TexanCowboy
I don't think any destroyer designer would put just four torpedoes on a destroyer, and hope to keep their job.

Worked okay for the Tribal, J, K, N, O, and P-classes. Among many, many others...

RA's stated the ship is primarily an ASW platform, the torpedoes are possibly insurance, much like they are on my Archer AA destroyers in the Danish Fleet.

Shows my ignorance of naval design. I normally consider six a minimum for my designs, but *shrugs*

3 tubes is totally acceptable not every destroyer is a part of Tokyo express.
Torpedo heavy DD's a an option not a norm.

I like to clarify my earlier statement.

I like this ship for it represent a futuristic approach to warship design. It is primary a ASW ship but will do good in any situation, it fast(enough) ,good seaboat, can defend it self from surface and air attacks.

Its a all around ship and the designers recognise that other ships are not the only enemy to a ship anymore.

I would mention that the 5.31'' guns are not DP, but I do realize that Italy doesn't have a DP mount between 4'' and 6''.

Red Admiral was posting since 2005 back stories about his navy building and developing advanced mounts.
With this we can say that his 135mm as at least as good as US Navy 5'' DP

Putting in a value for the length (8.5m) makes no difference to seakeeping or stability.

Another set of torpedoes would be nice, but they can't reasonably be fitted onto the ship. Torpedoes are heavy and sizeable. Lots of the WWII period destroyers started losing torpedo tubes in order to make way for radar and light AA.

Quoted

Red Admiral was posting since 2005 back stories about his navy building and developing advanced mounts. With this we can say that his 135mm as at least as good as US Navy 5'' DP

Not the 135/45. It's basically the historical gun in a twin mounting. Fairly good against surface targets, but not so great against aeroplanes, especially given the low elevation. Of course, before proximity fuses, large AA was pretty ineffectual. Italy did have a big experiment with the 152/53 dual purpose gun, but it's just too heavy to mount on destroyers. Hence a new 127mm is being developed, essentially being a scaled up version of the 76/62 (not automatic).

Are you going to make an 50s version aswell? This looks pretty good!

As a destroyer it makes perfect sense, actually its one of the better Italian destroyers of recent years IMHO. The ASW weapons are probably more crucial to future fleet safety than the torpedo or the gun. Look at RLHB's Nordmark news for just some of the views.

I've been messing around with future destroyers as numbers of main calibre guns will fall from 6-8 now to around 4. Newer and heaver semi-auto and auto mounts just eat into the weight limits and hull space. AA armament would be good with a 76mm auto but it would lack power for a surface engagement. The design probably has more seaworthiness than Italy would consider OTL but given Italy's commitments it makes sense. Personally I'd see a surface radar as a better bet than an aerial radar purely because this type of ship might not be suited to stand-off/ picket roles and because it lacks any serious AA firepower of its own. Saying that its not hard to see an AA variant of this design in the future.

Have you thought about a quintuple 600mm torpedo mount?

I still have problems with what my future destroyers will look like. Speed looks less and less worth pursuing, torpedo heavy concept that I was going for is rapidly becoming outdated with introduction of RADAR.


Basic idea behind this ship is probably what my next class will look like.

Quoted

As a destroyer it makes perfect sense, actually its one of the better Italian destroyers of recent years IMHO.

Recent Italian destroyers have been a bit all over the place. This is a more realistic appraisal of requirements.

For future RN destroyers, George Moore was pretty keen on a Daring with only two turrets. It'd be nice to get something with enough room to mount SeaCat later on. Might be able to squeeze in a single SeaSlug launcher with a few missiles.

Quoted

Personally I'd see a surface radar as a better bet than an aerial radar purely because this type of ship might not be suited to stand-off/ picket roles and because it lacks any serious AA firepower of its own.

The only surface radar Italy currently has (and not many of them) is EC3 which is shown in the inset view below. It's rather big and difficult to mount. Range is a bit low when mounted low down as well (~10-15km). A nice size air warning (proper search radars being a way off) radar seems a more useful investment. Below I've drawn in a EC7 microwave surface radar set on the mainmast. Longer range (25-30km) and much easier to fit in.

I'm not sure exactly what you mean about this ship lacking in AA firepower. It'd be difficult to cram any more light AA onto the ship. The quadruple powered weatherproof 37mm mountings should be very good for shooting down aeroplanes at short range, they just weigh 18tons which rather restricts things.

Quoted

Saying that its not hard to see an AA variant of this design in the future.

Future version with 4x127/64 dual purpose and 5x76/62 automatic. Anti-submarine rocket launcher aft of the torpedo tubes.

Quoted

Have you thought about a quintuple 600mm torpedo mount?

Not really, though I suppose it would fit. Probably not a bit enough gain to warrant spending design effort on it. Just use the standard quadruple mounting instead.

Quoted

Originally posted by Red Admiral
For future RN destroyers, George Moore was pretty keen on a Daring with only two turrets. It'd be nice to get something with enough room to mount SeaCat later on. Might be able to squeeze in a single SeaSlug launcher with a few missiles.

Hey stop reading my mind... maybe even Red Slug SSM version...



Well it doesn't lack firepower but since your describing a threat-warning set rather than a long-range set my former comment is no longer to this disscussion. IMO a vessel with a long-range set needs the tools to act on the info. No point knowing an aircraft is 20 miles away and you've only got a few popguns to defend yourself. You want something to reach out and knock 'em down. In this case it doesn't apply. I was thinking more of the later 40s.

The future version looks cool. I love that 1950s RN look, kinda like a super Type 15 on acid.