WesWorld

Gentlemen,

the early month of the South American War have revealed the potential of light and (very) fast light cruisers. The "Pony Express" made of the four Arion-class CLs (laid down 1927) is causing havoc among Argentinean shipping time and again. Thus the RSAN discusses if a follow-on design should be laid down (which is based on OTL Emile Bertin).

What is your opinion?

South African Light Cruiser laid down 1936

Displacement:
7.871 t light; 8.207 t standard; 9.077 t normal; 9.772 t full load

Dimensions: Length overall / water x beam x draught
555,57 ft / 541,34 ft x 61,68 ft x 19,03 ft (normal load)
169,34 m / 165,00 m x 18,80 m x 5,80 m

Armament:
9 - 5,91" / 150 mm guns (3x3 guns), 110,23lbs / 50,00kg shells, 1936 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, majority forward, 1 raised mount - superfiring
8 - 4,13" / 105 mm guns (4x2 guns), 35,32lbs / 16,02kg shells, 1936 Model
Dual purpose guns in deck mounts with hoists
on side, all amidships, all raised mounts - superfiring
12 - 1,57" / 40,0 mm guns (3x4 guns), 1,95lbs / 0,88kg shells, 1936 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
12 - 0,79" / 20,0 mm guns (6x2 guns), 0,24lbs / 0,11kg shells, 1936 Model
Machine guns in deck mounts
on side, evenly spread, 2 raised mounts
Weight of broadside 1.301 lbs / 590 kg
Shells per gun, main battery: 200
8 - 21,0" / 533 mm above water torpedoes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 1,97" / 50 mm 402,62 ft / 122,72 m 10,50 ft / 3,20 m
Ends: Unarmoured
Main Belt covers 114% of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 3,15" / 80 mm 1,97" / 50 mm 3,15" / 80 mm
2nd: 1,38" / 35 mm 0,98" / 25 mm 1,18" / 30 mm
3rd: 0,59" / 15 mm - -
4th: 0,39" / 10 mm - -

- Armour deck: 1,38" / 35 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 100.000 shp / 74.600 Kw = 34,74 kts
Range 8.000nm at 15,00 kts
Bunker at max displacement = 1.566 tons

Complement:
464 - 604

Cost:
£4,208 million / $16,832 million

Distribution of weights at normal displacement:
Armament: 154 tons, 1,7%
Armour: 1.163 tons, 12,8%
- Belts: 342 tons, 3,8%
- Torpedo bulkhead: 0 tons, 0,0%
- Armament: 231 tons, 2,5%
- Armour Deck: 590 tons, 6,5%
- Conning Tower: 0 tons, 0,0%
Machinery: 2.806 tons, 30,9%
Hull, fittings & equipment: 3.728 tons, 41,1%
Fuel, ammunition & stores: 1.205 tons, 13,3%
Miscellaneous weights: 20 tons, 0,2%

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
8.534 lbs / 3.871 Kg = 82,9 x 5,9 " / 150 mm shells or 1,3 torpedoes
Stability (Unstable if below 1.00): 1,07
Metacentric height 2,8 ft / 0,8 m
Roll period: 15,6 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0,39
Seaboat quality (Average = 1.00): 1,00

Hull form characteristics:
Hull has raised forecastle
and transom stern
Block coefficient: 0,500
Length to Beam Ratio: 8,78 : 1
'Natural speed' for length: 26,83 kts
Power going to wave formation at top speed: 64 %
Trim (Max stability = 0, Max steadiness = 100): 70
Bow angle (Positive = bow angles forward): 25,00 degrees
Stern overhang: 0,00 ft / 0,00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 30,51 ft / 9,30 m
- Forecastle (40%): 26,90 ft / 8,20 m (19,03 ft / 5,80 m aft of break)
- Mid (50%): 19,03 ft / 5,80 m
- Quarterdeck (15%): 19,03 ft / 5,80 m
- Stern: 19,03 ft / 5,80 m
- Average freeboard: 22,76 ft / 6,94 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 114,4%
- Above water (accommodation/working, high = better): 150,9%
Waterplane Area: 23.135 Square feet or 2.149 Square metres
Displacement factor (Displacement / loading): 113%
Structure weight / hull surface area: 99 lbs/sq ft or 482 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,92
- Longitudinal: 2,08
- Overall: 1,00
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform

An option would be to lay down a new multi-purpose/AAA cruiser, a follow-on to the class of 1934 but enlarged.

South African AA cruiser laid down 1936

Displacement:
7.631 t light; 7.970 t standard; 8.884 t normal; 9.615 t full load

Dimensions: Length overall / water x beam x draught
557,75 ft / 544,62 ft x 55,77 ft x 19,69 ft (normal load)
170,00 m / 166,00 m x 17,00 m x 6,00 m

Armament:
12 - 5,31" / 135 mm guns (6x2 guns), 75,07lbs / 34,05kg shells, 1936 Model
Dual purpose guns in turrets (on barbettes)
on centreline ends, evenly spread, 4 raised mounts - superfiring
16 - 1,57" / 40,0 mm guns (8x2 guns), 1,95lbs / 0,88kg shells, 1936 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
24 - 0,79" / 20,0 mm guns (4x6 guns), 0,24lbs / 0,11kg shells, 1936 Model
Machine guns in deck mounts
on side, evenly spread, all raised mounts
6 - 0,79" / 20,0 mm guns in single mounts, 0,24lbs / 0,11kg shells, 1936 Model
Machine guns in deck mounts
on side, evenly spread
Weight of broadside 939 lbs / 426 kg
Shells per gun, main battery: 300
8 - 21,0" / 533 mm above water torpedoes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 3,15" / 80 mm 384,19 ft / 117,10 m 11,48 ft / 3,50 m
Ends: Unarmoured
Main Belt covers 109% of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1,77" / 45 mm 1,38" / 35 mm 2,36" / 60 mm
3rd: 0,59" / 15 mm - -
4th: 0,39" / 10 mm - -
5th: 0,39" / 10 mm - -

- Armour deck: 1,57" / 40 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 93.834 shp / 70.000 Kw = 34,29 kts
Range 8.500nm at 15,00 kts
Bunker at max displacement = 1.645 tons

Complement:
456 - 594

Cost:
£3,872 million / $15,487 million

Distribution of weights at normal displacement:
Armament: 117 tons, 1,3%
Armour: 1.424 tons, 16,0%
- Belts: 573 tons, 6,4%
- Torpedo bulkhead: 0 tons, 0,0%
- Armament: 227 tons, 2,6%
- Armour Deck: 625 tons, 7,0%
- Conning Tower: 0 tons, 0,0%
Machinery: 2.633 tons, 29,6%
Hull, fittings & equipment: 3.386 tons, 38,1%
Fuel, ammunition & stores: 1.253 tons, 14,1%
Miscellaneous weights: 70 tons, 0,8%

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
9.301 lbs / 4.219 Kg = 123,9 x 5,3 " / 135 mm shells or 1,3 torpedoes
Stability (Unstable if below 1.00): 1,05
Metacentric height 2,3 ft / 0,7 m
Roll period: 15,5 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0,44
Seaboat quality (Average = 1.00): 1,01

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0,520
Length to Beam Ratio: 9,76 : 1
'Natural speed' for length: 26,62 kts
Power going to wave formation at top speed: 63 %
Trim (Max stability = 0, Max steadiness = 100): 69
Bow angle (Positive = bow angles forward): 20,00 degrees
Stern overhang: 2,62 ft / 0,80 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 28,87 ft / 8,80 m
- Forecastle (25%): 23,95 ft / 7,30 m
- Mid (59%): 23,95 ft / 7,30 m (15,75 ft / 4,80 m aft of break)
- Quarterdeck (15%): 15,75 ft / 4,80 m
- Stern: 15,75 ft / 4,80 m
- Average freeboard: 21,08 ft / 6,43 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 108,5%
- Above water (accommodation/working, high = better): 149,6%
Waterplane Area: 21.447 Square feet or 1.992 Square metres
Displacement factor (Displacement / loading): 115%
Structure weight / hull surface area: 93 lbs/sq ft or 454 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,94
- Longitudinal: 1,86
- 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

Option 3 is a follow-on to the class of 1929 and represents a heavily armed multi-purpose cruiser for fleet service.

So which to choose? Free capacity in the yards is rare as are resources.

Displacement:
8.640 t light; 9.021 t standard; 9.989 t normal; 10.763 t full load

Dimensions: Length overall / water x beam x draught
563,09 ft / 552,82 ft x 59,06 ft x 21,00 ft (normal load)
171,63 m / 168,50 m x 18,00 m x 6,40 m

Armament:
12 - 5,91" / 150 mm guns (4x3 guns), 110,23lbs / 50,00kg shells, 1936 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
8 - 4,53" / 115 mm guns (4x2 guns), 46,40lbs / 21,05kg shells, 1936 Model
Dual purpose guns in deck mounts with hoists
on side, all amidships, all raised mounts - superfiring
8 - 1,57" / 40,0 mm guns (4x2 guns), 1,95lbs / 0,88kg shells, 1936 Model
Breech loading guns in deck mounts
on side, evenly spread, all raised mounts
16 - 0,79" / 20,0 mm guns (4x4 guns), 0,24lbs / 0,11kg shells, 1936 Model
Breech loading guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 1.713 lbs / 777 kg
Shells per gun, main battery: 180

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 4,72" / 120 mm 342,85 ft / 104,50 m 10,66 ft / 3,25 m
Ends: Unarmoured
Main Belt covers 95% of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 4,72" / 120 mm 2,56" / 65 mm 4,72" / 120 mm
2nd: 1,38" / 35 mm 0,98" / 25 mm 1,38" / 35 mm
3rd: 0,59" / 15 mm - -
4th: 0,39" / 10 mm - -

- Armour deck: 1,97" / 50 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 85.791 shp / 64.000 Kw = 33,02 kts
Range 8.400nm at 15,00 kts
Bunker at max displacement = 1.742 tons

Complement:
499 - 649

Cost:
£4,272 million / $17,088 million

Distribution of weights at normal displacement:
Armament: 203 tons, 2,0%
Armour: 2.029 tons, 20,3%
- Belts: 729 tons, 7,3%
- Torpedo bulkhead: 0 tons, 0,0%
- Armament: 469 tons, 4,7%
- Armour Deck: 832 tons, 8,3%
- Conning Tower: 0 tons, 0,0%
Machinery: 2.407 tons, 24,1%
Hull, fittings & equipment: 3.951 tons, 39,6%
Fuel, ammunition & stores: 1.349 tons, 13,5%
Miscellaneous weights: 50 tons, 0,5%

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
12.862 lbs / 5.834 Kg = 124,9 x 5,9 " / 150 mm shells or 1,6 torpedoes
Stability (Unstable if below 1.00): 1,11
Metacentric height 2,8 ft / 0,8 m
Roll period: 14,9 seconds
Steadiness - As gun platform (Average = 50 %): 51 %
- Recoil effect (Restricted arc if above 1.00): 0,52
Seaboat quality (Average = 1.00): 1,00

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0,510
Length to Beam Ratio: 9,36 : 1
'Natural speed' for length: 26,94 kts
Power going to wave formation at top speed: 61 %
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: 28,22 ft / 8,60 m
- Forecastle (20%): 24,93 ft / 7,60 m
- Mid (48%): 24,93 ft / 7,60 m (17,06 ft / 5,20 m aft of break)
- Quarterdeck (15%): 17,06 ft / 5,20 m
- Stern: 17,06 ft / 5,20 m
- Average freeboard: 21,10 ft / 6,43 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 95,4%
- Above water (accommodation/working, high = better): 178,3%
Waterplane Area: 22.833 Square feet or 2.121 Square metres
Displacement factor (Displacement / loading): 117%
Structure weight / hull surface area: 105 lbs/sq ft or 513 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,93
- Longitudinal: 1,79
- Overall: 1,00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent

The armor of Option Three is attractive, but it doesn't have as high a seaboat and gunnery rating as the other two, and loses a knot of speed besides. In terms of cost, I think Option Two is the best blend of speed, guns, and armor of the three designs...

I like option 2 myself...

Fast, seaworthy, stable, sacrifacing weight of fire but countered somewhat by what would surely be a higher rate of fire, 6 turrets minimise the loss of capability from a single turret hit, lots and lots of AA (Dido-kyrie's big sister?)

Given the SAE's propencity for smaller ships I'd say design 3 would be very valuable due to her firepower.
She does suffer from lack of seakeeping and steadiness though. Perhaps if she looses a half know speed she should turn out nicely. Shes also only slightly more expencive than design 1.

So there seems to be a preference for design 2 - which I actually did not expect. Instead I thought you guys would be voring for option three because of her superior broadside. There are many 12x6" cruisers around in WesWorld but the RSAN has laid down only one such class so far....

Anyway, thanks for your opinions. I got what I asked for. :o)

I think you're probably better off going with smaller and faster and more speciallised rather than trying to cram all hte requirements into a larger ship that'll spend most of it's life cruising at 12-15knts in the Southern Ocean.

I would go with option three.

I've never been convinced that AA Cruisers are worthy of the expense. Older types can be refitted much more cheaply.

I think the extra armour and firepower of design three is worth the loss of some speed. Option one is quite good for fast raiding etc but maybe its too much of a luxury if funds are tight.

I'll second what Gavin said. The Pony Express were fast, heavily armed, and expendable. The AA cruiser lacks the punch of the Arions, and the other designs are not nearly as expendable.

I recognize that repeating Arion is not possible with newer hull strength guidelines, but your current Fenris class could probably do much the same job.

Repeating the Arions is possible (see below). I shaved away 0,15kn and 400nm range and increased secondary caliber instead. That´s a trade-off worth it, methinks.

This really is a decision about strategy. Cruiser size will generally go up without any treaty. We´ve already seen many large light cruisers with 12 and more main guns. So the question is if the RSAN should follow that trend or instead bet on small "expendable" units and let CAs or larger units deal with the heavy armed but slow (in most cases) super-CLs?


South African Light Cruiser laid down 1936

Displacement:
5.840 t light; 6.103 t standard; 6.841 t normal; 7.432 t full load

Dimensions: Length overall / water x beam x draught
541,22 ft / 524,93 ft x 50,36 ft x 19,52 ft (normal load)
164,97 m / 160,00 m x 15,35 m x 5,95 m

Armament:
8 - 5,91" / 150 mm guns (4x2 guns), 110,23lbs / 50,00kg shells, 1936 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
8 - 4,13" / 105 mm guns (4x2 guns), 35,32lbs / 16,02kg shells, 1936 Model
Dual purpose guns in deck mounts
on side, all amidships, all raised mounts - superfiring
8 - 1,57" / 40,0 mm guns (4x2 guns), 1,95lbs / 0,89kg shells, 1936 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, 3 raised mounts
8 - 0,79" / 20,0 mm guns (4x2 guns), 0,24lbs / 0,11kg shells, 1936 Model
Machine guns in deck mounts
on side, evenly spread, 2 raised mounts
Weight of broadside 1.182 lbs / 536 kg
Shells per gun, main battery: 180
16 - 21,0" / 533 mm above water torpedoes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 1,57" / 40 mm 462,60 ft / 141,00 m 9,84 ft / 3,00 m
Ends: Unarmoured
Main Belt covers 136% of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1,77" / 45 mm 0,98" / 25 mm 1,38" / 35 mm
2nd: 0,98" / 25 mm 0,39" / 10 mm -
3rd: 0,59" / 15 mm - -
4th: 0,39" / 10 mm - -

- Armour deck: 0,59" / 15 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 88.472 shp / 66.000 Kw = 35,36 kts
Range 8.000nm at 15,00 kts
Bunker at max displacement = 1.329 tons

Complement:
375 - 488

Cost:
£3,532 million / $14,130 million

Distribution of weights at normal displacement:
Armament: 140 tons, 2,1%
Armour: 595 tons, 8,7%
- Belts: 284 tons, 4,1%
- Torpedo bulkhead: 0 tons, 0,0%
- Armament: 118 tons, 1,7%
- Armour Deck: 194 tons, 2,8%
- Conning Tower: 0 tons, 0,0%
Machinery: 2.482 tons, 36,3%
Hull, fittings & equipment: 2.547 tons, 37,2%
Fuel, ammunition & stores: 1.002 tons, 14,6%
Miscellaneous weights: 75 tons, 1,1%

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
4.071 lbs / 1.846 Kg = 39,5 x 5,9 " / 150 mm shells or 0,8 torpedoes
Stability (Unstable if below 1.00): 1,09
Metacentric height 2,1 ft / 0,6 m
Roll period: 14,6 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0,61
Seaboat quality (Average = 1.00): 1,00

Hull form characteristics:
Hull has rise forward of midbreak
and transom stern
Block coefficient: 0,464
Length to Beam Ratio: 10,42 : 1
'Natural speed' for length: 26,18 kts
Power going to wave formation at top speed: 62 %
Trim (Max stability = 0, Max steadiness = 100): 70
Bow angle (Positive = bow angles forward): 30,00 degrees
Stern overhang: 0,00 ft / 0,00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 28,22 ft / 8,60 m
- Forecastle (27%): 22,64 ft / 6,90 m
- Mid (50%): 22,64 ft / 6,90 m (14,76 ft / 4,50 m aft of break)
- Quarterdeck (15%): 14,76 ft / 4,50 m
- Stern: 14,76 ft / 4,50 m
- Average freeboard: 19,30 ft / 5,88 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 135,0%
- Above water (accommodation/working, high = better): 94,0%
Waterplane Area: 17.728 Square feet or 1.647 Square metres
Displacement factor (Displacement / loading): 101%
Structure weight / hull surface area: 81 lbs/sq ft or 394 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,83
- Longitudinal: 1,80
- 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 adequate
Ship has slow, easy roll, a good, steady gun platform

Hi...

Here´s a first sketch of what the AAA cruiser could look like. Comments?

Quoted

Originally posted by HoOmAn
This really is a decision about strategy. Cruiser size will generally go up without any treaty. We´ve already seen many large light cruisers with 12 and more main guns. So the question is if the RSAN should follow that trend or instead bet on small "expendable" units and let CAs or larger units deal with the heavy armed but slow (in most cases) super-CLs?

The Dutch see two roles for the lighter cruisers. One is the expendable raider/high seas scout/night striker/destroyer associate - faster and lighter, using speed to dictate terms of engagement.

The second is that 12-gun CL, expected to be useful in close quarters island fighting, night fighting, and provide the screen against enemy light elements in a fleet engagement- overwhelming speed not be necessary.

However, the latter roles also do not fit the RSAN as well.
The majority of tasks are high seas, not inter-island. I'd say an increased number of hulls with higher speeds would be more important from an overall war fighting consideration.