WesWorld

CLs aren't a type I'm good at; their necessities war with my instincts. Nevertheless, the Nords have a lot of them, and seem to have a two-tier approach to the type - there are the 'fleet' type, the carrier escort Luleas, and a smaller, more affordable type that I suspect is used more for things like commerce protection and raiding.

The mainstay of the latter, however, are refitted Tampere class ships laid down in 1915. Obviously, as part of my ongoing 'update all the things!' project, these will need to be replaced.

So I'm looking at something like this...

Looks cheap. Perhaps too cheap to be really effective though. The seakeeping is poor and oceanic work will be their mainstay. I think its worth making the hull a little bigger to improve the seaworthiness. The armament seems fine, belt armour is ok but I would perhaps add 10-15mm to the deck armour but that's a matter of personal preference I guess. I think you can get something perfect within 6,000tons or less and that's still fairly economic by CL standards.

I find myself in agreement with Hood - as is, this design is trying to carry too much armament on too little hull. There are two approaches to resolving the issue - increase the size of the vessel, or adjust the armament.

I'll speak to the latter first. The OTL British Arethusa was designed in the 1930s as a 'minimum' trade protection cruiser. Six carried only six 6-inch guns, and if you really want such a small cruiser for trade protection work, I think you should limit your main armament to six 15cm. I suspect that doing so would increase the seakeeping a bit. It might also allow you to adjust the belt armor, which I think is too thin.

A better alternative, in my mind, is a larger vessel of 6,500 - 7,000 tons light; that would allow you to carry the armament you've chosen on a much better seaboat, would permit you to provide better protection, and perhaps allow for more speed - at 30 knots the current design would be hard pressed to run down a raiding cruiser or escape from a superior enemy.

I've taken the liberty of offering an unsolicited proposal; I think it meet your needs or at least serve as a starting point for further refinement.



Deschimag Export Proposal, Nordmark Light Cruiser laid down 1943

Displacement: 7,075 t light; 7,388 t standard; 8,300 t normal; 9,029 t full load

Dimensions: Length overall / water x beam x draught

557.71 ft / 547.90 ft x 56.10 ft x 17.22 ft (normal load) [169.99 m / 167.00 m x 17.10 m x 5.25 m]

Armament:

8 - 5.91" / 150 mm guns (4x2 guns), 102.98lbs / 46.71kg shells, 1943 Model Breech loading guns in turrets (on barbettes) on centreline ends, evenly spread, 2 raised mounts - superfiring
8 - 4.33" / 110 mm guns (4x2 guns), 40.61lbs / 18.42kg shells, 1943 Model Anti-aircraft guns in deck mounts with hoists on side, all amidships
32 - 1.57" / 40.0 mm guns (4x8 guns), 1.95lbs / 0.89kg shells, 1943 Model Anti-aircraft guns in deck mounts on centreline, all amidships, all raised mounts - superfiring
Weight of broadside 1,211 lbs / 549 kg
Shells per gun, main battery: 200
8 - 24.0" / 610 mm above water torpedoes

Armour:

Belts: Width (max) Length (avg) Height (avg)
Main: 3.15" / 80 mm 328.08 ft / 100.00 m 10.83 ft / 3.30 m
Ends: Unarmoured
Main Belt covers 92 % of normal length

Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 3.94" / 100 mm 1.97" / 50 mm 1.97" / 50 mm
2nd: 0.98" / 25 mm 0.98" / 25 mm -
3rd: 0.59" / 15 mm - -

Armour deck: 1.97" / 50 mm, Conning tower: 3.15" / 80 mm

Machinery:

Oil fired boilers, steam turbines, Geared drive, 3 shafts, 69,306 shp / 51,702 Kw = 32.00 kts
Range 3,000nm at 24.00 kts
Bunker at max displacement = 1,641 tons

Complement: 434 - 565

Cost: £4.093 million / $16.374 million

Distribution of weights at normal displacement:

Armament: 151 tons, 1.8 %
Armour: 1,529 tons, 18.4 %
- Belts: 474 tons, 5.7 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 215 tons, 2.6 %
- Armour Deck: 812 tons, 9.8 %
- Conning Tower: 28 tons, 0.3 %
Machinery: 1,790 tons, 21.6 %
Hull, fittings & equipment: 3,455 tons, 41.6 %
Fuel, ammunition & stores: 1,225 tons, 14.8 %
Miscellaneous weights: 150 tons, 1.8 %

Overall survivability and seakeeping ability:

Survivability (Non-critical penetrating hits needed to sink ship): 13,013 lbs / 5,902 Kg = 126.4 x 5.9 " / 150 mm shells or 1.7 torpedoes
Stability (Unstable if below 1.00): 1.10
Metacentric height 2.5 ft / 0.8 m
Roll period: 14.8 seconds
Steadiness - As gun platform (Average = 50 %): 72 %
- Recoil effect (Restricted arc if above 1.00): 0.53
Seaboat quality (Average = 1.00): 1.28

Hull form characteristics:

Hull has a flush deck and transom stern
Block coefficient: 0.549
Length to Beam Ratio: 9.77: 1
'Natural speed' for length: 26.62 kts
Power going to wave formation at top speed: 59 %
Trim (Max stability = 0, Max steadiness = 100): 56
Bow angle (Positive = bow angles forward): 18.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 30.18 ft / 9.20 m
- Forecastle (20 %): 24.93 ft / 7.60 m
- Mid (50 %): 19.69 ft / 6.00 m
- Quarterdeck (15 %): 19.69 ft / 6.00 m
- Stern: 19.69 ft / 6.00 m
- Average freeboard: 21.94 ft / 6.69 m

Ship space, strength and comments:

Space - Hull below water (magazines/engines, low = better): 87.2 %
- Above water (accommodation/working, high = better): 156.6 %
Waterplane Area: 22,305 Square feet or 2,072 Square metres
Displacement factor (Displacement / loading): 128 %
Structure weight / hull surface area: 93 lbs/sq ft or 453 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.93
- Longitudinal: 1.99
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

Considering the seastate that Nordish vessels might have to sail in I think that one is better.

Quoted

Originally posted by TheCanadian
Considering the seastate that Nordish vessels might have to sail in I think that one is better.

Quite so; whether the North Atlantic or the Roaring Forties, Nordmark has commitments in areas of rough seas. Seakeeping is a paramount concern. I suppose one could cut a couple hundred tons off the design, but to me that would be cheese-paring.

Yeah, I don't think I'm going to do any better than that.

Especially not anywhere near that weight.

Quoted

Originally posted by Valles
Yeah, I don't think I'm going to do any better than that.

Especially not anywhere near that weight.

I tried a variant of the design with only six 15cm guns, and slightly smaller dimensions. It only saved about 500 tons. I really didn't see the value in it; minimal cruisers would be eaten up by anything larger.

Valles take a look at this thread; Argentine Light Cruiser Competition

The submissions all came out around what Bruce has proposed here. Some we slightly bigger and some slightly smaller but the 7,000 ton mark is a good general purpose design. I'd prefer three triples to four twins myself but that again is personal preference. I agree with Bruce that 3x2 is too weak.


I've also taken the liberty of an unsolicited proposal. Slightly heavier than the German but with triples and more seaworthiness but slightly lower range (still ~7,500 @ 15kts).

Vickers Export Light Cruiser, Great Britain Light Cruiser laid down 1943

Displacement:
7,360 t light; 7,687 t standard; 8,544 t normal; 9,230 t full load

Dimensions: Length overall / water x beam x draught
566.65 ft / 555.00 ft x 56.60 ft x 17.00 ft (normal load)
172.71 m / 169.16 m x 17.25 m x 5.18 m

Armament:
9 - 5.91" / 150 mm guns (3x3 guns), 102.98lbs / 46.71kg shells, 1943 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, majority forward, 1 raised mount - superfiring
8 - 4.33" / 110 mm guns (4x2 guns), 40.61lbs / 18.42kg shells, 1943 Model
Dual purpose guns in deck mounts with hoists
on side, all aft
24 - 1.57" / 40.0 mm guns (6x4 guns), 1.95lbs / 0.89kg shells, 1943 Model
Anti-aircraft guns in deck mounts
on side ends, evenly spread, all raised mounts - superfiring
8 - 0.79" / 20.0 mm guns (4x2 guns), 0.24lbs / 0.11kg shells, 1943 Model
Anti-aircraft guns in deck mounts
on side ends, evenly spread, all raised mounts - superfiring
Weight of broadside 1,301 lbs / 590 kg
Shells per gun, main battery: 200
8 - 23.6" / 600 mm above water torpedoes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 3.15" / 80 mm 330.00 ft / 100.58 m 10.00 ft / 3.05 m
Ends: Unarmoured
Main Belt covers 91 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 3.00" / 76 mm 2.00" / 51 mm 2.00" / 51 mm
2nd: 1.00" / 25 mm 1.00" / 25 mm 1.00" / 25 mm
3rd: 0.50" / 13 mm - -

- Armour deck: 2.00" / 51 mm, Conning tower: 2.00" / 51 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 70,750 shp / 52,780 Kw = 32.01 kts
Range 2,750nm at 24.00 kts
Bunker at max displacement = 1,542 tons

Complement:
443 - 577

Cost:
£4.254 million / $17.017 million

Distribution of weights at normal displacement:
Armament: 163 tons, 1.9 %
Armour: 1,503 tons, 17.6 %
- Belts: 441 tons, 5.2 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 191 tons, 2.2 %
- Armour Deck: 853 tons, 10.0 %
- Conning Tower: 18 tons, 0.2 %
Machinery: 1,827 tons, 21.4 %
Hull, fittings & equipment: 3,688 tons, 43.2 %
Fuel, ammunition & stores: 1,184 tons, 13.9 %
Miscellaneous weights: 180 tons, 2.1 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
14,456 lbs / 6,557 Kg = 140.4 x 5.9 " / 150 mm shells or 1.8 torpedoes
Stability (Unstable if below 1.00): 1.13
Metacentric height 2.7 ft / 0.8 m
Roll period: 14.5 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.56
Seaboat quality (Average = 1.00): 1.37

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0.560
Length to Beam Ratio: 9.81 : 1
'Natural speed' for length: 26.75 kts
Power going to wave formation at top speed: 59 %
Trim (Max stability = 0, Max steadiness = 100): 51
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 32.00 ft / 9.75 m
- Forecastle (20 %): 25.00 ft / 7.62 m
- Mid (75 %): 25.00 ft / 7.62 m (14.00 ft / 4.27 m aft of break)
- Quarterdeck (15 %): 14.00 ft / 4.27 m
- Stern: 14.00 ft / 4.27 m
- Average freeboard: 22.81 ft / 6.95 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 87.5 %
- Above water (accommodation/working, high = better): 179.7 %
Waterplane Area: 23,044 Square feet or 2,141 Square metres
Displacement factor (Displacement / loading): 129 %
Structure weight / hull surface area: 95 lbs/sq ft or 462 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.91
- Longitudinal: 2.19
- Overall: 1.00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

Misc weight includes
Two radar sets
Provision for two aircraft and catapult
8 reload torpedoes and handling gear