WesWorld

The RCN has taken a momentary surplus of naval funding to modernize the Diana class; Considered too small for real cruiser duties, they are being rebuilt into Destroyer flagships. To this end, they've been reengined for weight reduction and a slight increase in top speed, with the elderly SP guns replaced with prototypes of the automated DP mounts designed for the upcoming batch of Fleet Destroyers, and a heavy Flak battery to replace the superflous 4" single mounts.



HMCS Diana, Canadian (Ex-British) Light Cruiser laid down 1925 (Engine 1937)

Displacement:
4,400 t light; 4,587 t standard; 5,240 t normal; 5,762 t full load

Dimensions: Length overall / water x beam x draught
445.89 ft / 440.00 ft x 44.00 ft x 18.00 ft (normal load)
135.91 m / 134.11 m x 13.41 m x 5.49 m

Armament:
6 - 5.50" / 140 mm guns (3 mounts), 83.19lbs / 37.73kg shells, 1940 Model
Automatic rapid fire guns in turrets (on barbettes)
on centreline ends, majority aft, 3 raised guns - superfiring
48 - 1.57" / 40.0 mm guns (6x8 guns), 1.95lbs / 0.89kg shells, 1937 Model
Anti-aircraft guns in deck mounts
on side, all amidships, all raised mounts - superfiring
12 - 0.79" / 20.0 mm guns (6x2 guns), 0.24lbs / 0.11kg shells, 1925 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 596 lbs / 270 kg
Shells per gun, main battery: 225
8 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 1.50" / 38 mm 416.00 ft / 126.80 m 8.00 ft / 2.44 m
Ends: Unarmoured
Main Belt covers 145 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 2.00" / 51 mm 0.50" / 13 mm 0.50" / 13 mm
2nd: 0.50" / 13 mm - -

- Armour deck: 0.80" / 20 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 70,208 shp / 52,375 Kw = 32.50 kts
Range 8,000nm at 15.00 kts
Bunker at max displacement = 1,175 tons

Complement:
307 - 400

Cost:
£1.635 million / $6.538 million

Distribution of weights at normal displacement:
Armament: 87 tons, 1.7 %
Armour: 434 tons, 8.3 %
- Belts: 196 tons, 3.7 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 43 tons, 0.8 %
- Armour Deck: 196 tons, 3.7 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 1,946 tons, 37.1 %
Hull, fittings & equipment: 1,838 tons, 35.1 %
Fuel, ammunition & stores: 840 tons, 16.0 %
Miscellaneous weights: 95 tons, 1.8 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
3,619 lbs / 1,642 Kg = 43.5 x 5.5 " / 140 mm shells or 0.7 torpedoes
Stability (Unstable if below 1.00): 1.25
Metacentric height 2.2 ft / 0.7 m
Roll period: 12.5 seconds
Steadiness - As gun platform (Average = 50 %): 51 %
- Recoil effect (Restricted arc if above 1.00): 0.47
Seaboat quality (Average = 1.00): 1.01

Hull form characteristics:
Hull has low quarterdeck
Block coefficient: 0.526
Length to Beam Ratio: 10.00 : 1
'Natural speed' for length: 20.98 kts
Power going to wave formation at top speed: 65 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 15.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 22.00 ft / 6.71 m
- Forecastle (20 %): 21.00 ft / 6.40 m
- Mid (50 %): 21.00 ft / 6.40 m
- Quarterdeck (35 %): 13.00 ft / 3.96 m (21.00 ft / 6.40 m before break)
- Stern: 13.00 ft / 3.96 m
- Average freeboard: 18.28 ft / 5.57 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 135.6 %
- Above water (accommodation/working, high = better): 123.2 %
Waterplane Area: 13,215 Square feet or 1,228 Square metres
Displacement factor (Displacement / loading): 102 %
Structure weight / hull surface area: 72 lbs/sq ft or 353 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.81
- Longitudinal: 2.37
- Overall: 0.90
Caution: Hull subject to strain in open-sea
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent

40 tons - additional weight of DP mounts
30 tons - ASW and Radar
20 tons - Flagship Facilities

Quoted

Originally posted by ShinRa_Inc
The RCN has taken a momentary surplus of naval funding to modernize the Diana class;

Oh, the SAE could also make good use of some canadian surplus funding. Just send you rmoney and we´ll build something nice. :o)

Quoted

Originally posted by ShinRa_Inc
Armament:
6 - 5.50" / 140 mm guns (3 mounts), 83.19lbs / 37.73kg shells, 1940 Model
Automatic rapid fire guns in turrets (on barbettes)
on centreline ends, majority aft, 3 raised guns - superfiring

Suggest "2 raised guns" rather than 3. Might be more correct.

Yeah, that's an artifact from another rebuild Idea I had a few years ago....fixing it frees up another .01 hull strength, but I can't think of much else to do with it. My attempts to get true Destroyer-level speed would mean stripping off all the ship's armour, which doesn't seem that practical, and they probably have more flak than is really neccesary already. The only thing I could think of is a bit more Misc weight and put some aviation facilities on them, but I'm iffy on that for a platform this small.

Another pass at the concept; essentially a .5 knot loss in speed, a bit more range, and swapping two of the octuple 40mm for another 5.5" turret midships. This seems less 'doable' from an objective standpoint, but would result in a better cruiser-weight ship.



HMCS Diana, Canadian (Ex-British) Light Cruiser laid down 1925 (Engine 1937)

Displacement:
4,327 t light; 4,528 t standard; 5,240 t normal; 5,809 t full load

Dimensions: Length overall / water x beam x draught
445.89 ft / 440.00 ft x 44.00 ft x 18.00 ft (normal load)
135.91 m / 134.11 m x 13.41 m x 5.49 m

Armament:
8 - 5.50" / 140 mm guns (4x2 guns), 83.19lbs / 37.73kg shells, 1940 Model
Automatic rapid fire guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
32 - 1.57" / 40.0 mm guns (6 mounts), 1.95lbs / 0.88kg shells, 1937 Model
Anti-aircraft guns in deck mounts
on side, all amidships, all raised guns - superfiring
12 - 0.79" / 20.0 mm guns (6x2 guns), 0.24lbs / 0.11kg shells, 1925 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 731 lbs / 331 kg
Shells per gun, main battery: 225
8 - 21.0" / 533.4 mm above water torpedoes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 1.50" / 38 mm 416.00 ft / 126.80 m 8.00 ft / 2.44 m
Ends: Unarmoured
Main Belt covers 145 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 2.00" / 51 mm 0.50" / 13 mm 0.50" / 13 mm
2nd: 0.50" / 13 mm - -

- Armour deck: 0.80" / 20 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 65,743 shp / 49,044 Kw = 32.00 kts
Range 8,750nm at 15.00 kts
Bunker at max displacement = 1,280 tons

Complement:
307 - 400

Cost:
£1.627 million / $6.510 million

Distribution of weights at normal displacement:
Armament: 108 tons, 2.1 %
Armour: 446 tons, 8.5 %
- Belts: 196 tons, 3.7 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 55 tons, 1.0 %
- Armour Deck: 196 tons, 3.7 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 1,822 tons, 34.8 %
Hull, fittings & equipment: 1,855 tons, 35.4 %
Fuel, ammunition & stores: 913 tons, 17.4 %
Miscellaneous weights: 95 tons, 1.8 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
3,817 lbs / 1,731 Kg = 45.9 x 5.5 " / 140 mm shells or 0.7 torpedoes
Stability (Unstable if below 1.00): 1.24
Metacentric height 2.1 ft / 0.7 m
Roll period: 12.6 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0.59
Seaboat quality (Average = 1.00): 1.04

Hull form characteristics:
Hull has low quarterdeck
Block coefficient: 0.526
Length to Beam Ratio: 10.00 : 1
'Natural speed' for length: 20.98 kts
Power going to wave formation at top speed: 64 %
Trim (Max stability = 0, Max steadiness = 100): 48
Bow angle (Positive = bow angles forward): 15.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 22.00 ft / 6.71 m
- Forecastle (20 %): 21.00 ft / 6.40 m
- Mid (50 %): 21.00 ft / 6.40 m
- Quarterdeck (35 %): 13.00 ft / 3.96 m (21.00 ft / 6.40 m before break)
- Stern: 13.00 ft / 3.96 m
- Average freeboard: 18.28 ft / 5.57 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 131.0 %
- Above water (accommodation/working, high = better): 123.2 %
Waterplane Area: 13,215 Square feet or 1,228 Square metres
Displacement factor (Displacement / loading): 104 %
Structure weight / hull surface area: 73 lbs/sq ft or 356 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.80
- Longitudinal: 2.35
- Overall: 0.90
Caution: Hull subject to strain in open-sea
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent

40 tons - additional weight of DP mounts
30 tons - ASW and Radar
20 tons - Flagship Facilities

Where to place the magatins for that midship turret? Propellant needs to be protected from heat,

The magazine for the amidships turret would be in the forward engine room. You only seem to get a 60° firing arc on each beam as well so it's probably not worth it.

Agreed.

That's pretty much what I thought; In theory, the ship is being reengined and could be worked around a new turret, but that's a long shot. I can't really think of anything else to try doing to improve the ships, sadly.

Add vertical armour? 1.5" belt isn't spectacular, IMHO...

Not sure if belt alterations are all that important for what's going to be essentially a Destroyer Leader.

Fiddling a bit, I could get up to a 3 inch belt and 32 knots...or lose the belt entirely and get 33.25 knots.

Opinions? Keeping in mind these ships are supposed to operate (in theory) with the 35 knot DDs I have.

I agree with Shin on the armour belt, its good enough for a DDL and I'd hate to lose it either. My suggestion would be to use design 'A' but with an additional 40mm mount between the bridge and the forward 5.5" mount.

You'd also benifit from more AA dirrectors, perhaps a new dirrector design as well?

Yeah, directors I can replace (I've got the ones on the Manitoba and Labrador graphics). Fitting a 7th Octuple40mm is doable...but I thought I was already pushing feasibility with the 6 of 'em.

In general, if anyone's got any ideas either for specifics or even their place in the RCN, feel free to chime in; They're too small to fit in with the rest of the cruiser fleet, and there's not enough of them to establish a mission for them seperate from my other cruisers. And on the other end of the spectrum, they aren't much better armed than my Tribal DDs, but heavier and slower. Disposing of them seems a waste (they're not particularly old ships), it's just hard finding a role for them.

I would stick to Design A. Six 40mm seems more than enough. Another two torpedo mounts might be a worthy addition though.

I wouldn't change the armour, I don't think its worth it nor seriously messing around with the machinery.
As DDLs they might prove a little slow but as you say they are too new to scrap but I suppose you could convert them to training ships.

Yes, ditto what Hood said.

They would make excellent training ships acctually.

That's a thought. the Chesters are probably killing more recruits through Tetanus than training them at this point...

That'd mean doing something about the Chesters tho...I don't think I need 5 cruisers and a carrier dedicated to training.

Quoted

Originally posted by ShinRa_Inc
That's a thought. the Chesters are probably killing more recruits through Tetanus than training them at this point...

If Canada thinks the Chesters are old, then Bulgaria will point out Stara Zagora... There are a few Bulgarian COs who are younger than their navy's fourth-largest warship!

Quoted

That'd mean doing something about the Chesters tho...I don't think I need 5 cruisers and a carrier dedicated to training.

The answer is obvious. You must sell the carrier!

Considering that it is possible that every nation can turn against your nation, the Philippines is the best nation to sell it to. By the time you go to battle against them, the Carrier would have suffered a serious case of *KABOOM* and can't be used against you. You get money and you do not have to worry that it will become a pain later.