Cruisers for South America

[Blackbuck]

Ideally I think something like this would be the desired layout, perhaps using an existing drawing hull wasn't the best practice!



Sticking with the four shafts it'd allow them to be quite compact rather than the current ad-hoc layout

[Garlicdesign]

Hello again!

Here's my five cents; I needed a Brazilian CA for the WW2 edition of 'Thiaria: Other People's Ships' anyway, mostly as cannon fodder for the Thiarians: An early to mid 1930s vintage design for Brazil based upon the Apollo/Sydney-Type of the RN. The catapult installation amidships resembles the one installed in HMS Essex, with two fixed cats facing forward and outboard in a 60 degree angle and a single big crane in between. Unfortunately, my Springsharp crashed, so I have not yet checked it for feasibilty, but the hull at 180m (cwl) x 17,5m x 6,5m should easily be large enough for the equipment installed including a standard 80.000hp engine.



Greetings
GD

[Krakatoa]

Blackbuck: I like the design (I have always liked the G3/Nelson designs) but in comparison to the G3/Nelson you have a very short length of bow from A turret forward. There is a lot of weight forward without the buoyancy to counteract it. Also the turrets are the mk.1 twins with no modifications and called triples. There is normally a slight increase in length of the turret to balance out the extra breadth. I can see your problem with shafts and engine rooms, it may be that you have to put your power output through two shafts a'la Nelson. Anything up to 100,000shp through two shafts should be ok. After all the French were doing that regularly with their destroyers and cruisers.

Hey GD,
nice looking cruiser. The Amphion/Sydney design was in my opinion one of the best looking ever done. The only reason I didn't use it for this challenge is I thought the design might be a bit too old for the timespan.

[Blackbuck]

I should add that the following drawing is what I'm basing the nucleus of my idea off of...



The turrets are indeed stock doubles because short of making them up there's no real way around making them realistic(ish) other than what is on the plan here which I'm guessing is entirely notional at that point.
Two shafts might not actually be such a bad idea come to think of it.

[Krakatoa]

The turrets on the plan look like enlarged triple 6" as used on the Towns.

Maybe the turrets Rowdy36 did for his 8" Recherché cruiser might suit.

Having another look at the Ypres in Rowdy36's topic, it would probably suit one of the South American countries as is. If a tad big.

[Blackbuck]

After some tinkering and poking, progress!

[apdsmith]

Hi all,

I'm not sure quite how cheeky this is, but I've been thinking about an NSWE-ish solution ... I've yet to commit pen to paper (or mouse to PNG, I guess) but thought I'd get comment on whether that meets with the spirit of the rules, and also, any thoughts on feasibility of the spoiler'd SpringSharp...

This ship is deliberately overbuilt in the Treaty configuration, as a switch to 3x2 203mm (that is, three twin turrets) is planned for. If it's a good design, might well keep it as NSWE's WNT Light Cruiser, although it does sacrifice some machinery space to a longer-than-usual forecastle and stern (note the good seakeeping, always a concern for NSWE)

SchnellKreuzer 1930, New Saxe-Weimar-Eisenach Light Cruiser laid down 1930

Displacement:
8,774 t light; 9,074 t standard; 9,916 t normal; 10,590 t full load

Dimensions: Length overall / water x beam x draught
599.37 ft / 574.15 ft x 59.06 ft x 21.33 ft (normal load)
182.69 m / 175.00 m x 18.00 m x 6.50 m

Armament:
9 - 5.87" / 149 mm guns (3x3 guns), 100.31lbs / 45.50kg shells, 1930 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, majority aft, 1 raised mount aft - superfiring
10 - 3.46" / 88.0 mm guns in single mounts, 22.05lbs / 10.00kg shells, 1930 Model
Quick firing guns in deck mounts with hoists
on side, all amidships, 4 raised mounts - superfiring
12 - 1.46" / 37.0 mm guns (6x2 guns), 1.64lbs / 0.74kg shells, 1930 Model
Quick firing guns in deck mounts
on side, evenly spread
Weight of broadside 1,143 lbs / 518 kg
Shells per gun, main battery: 150
12 - 21.0" / 533 mm above water torpedoes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 3.94" / 100 mm 315.78 ft / 96.25 m 9.22 ft / 2.81 m
Ends: 0.79" / 20 mm 258.33 ft / 78.74 m 9.22 ft / 2.81 m
Main Belt covers 85 % of normal length
Main belt does not fully cover magazines and engineering spaces

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 3.94" / 100 mm 1.97" / 50 mm 3.94" / 100 mm
2nd: 1.97" / 50 mm 0.98" / 25 mm 1.97" / 50 mm
3rd: 1.57" / 40 mm 0.79" / 20 mm -

- Armour deck: 1.57" / 40 mm, Conning tower: 1.97" / 50 mm

Machinery:
Oil fired boilers, steam turbines plus diesel motors,
Electric motors, 2 shafts, 82,470 shp / 61,522 Kw = 33.00 kts
Range 4,000nm at 19.00 kts
Bunker at max displacement = 1,515 tons

Complement:
496 - 645

Cost:
£3.246 million / $12.986 million

Distribution of weights at normal displacement:
Armament: 142 tons, 1.4 %
Armour: 1,545 tons, 15.6 %
- Belts: 560 tons, 5.7 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 294 tons, 3.0 %
- Armour Deck: 672 tons, 6.8 %
- Conning Tower: 20 tons, 0.2 %
Machinery: 2,499 tons, 25.2 %
Hull, fittings & equipment: 4,438 tons, 44.8 %
Fuel, ammunition & stores: 1,142 tons, 11.5 %
Miscellaneous weights: 150 tons, 1.5 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
13,914 lbs / 6,311 Kg = 137.6 x 5.9 " / 149 mm shells or 1.7 torpedoes
Stability (Unstable if below 1.00): 1.12
Metacentric height 2.8 ft / 0.9 m
Roll period: 14.8 seconds
Steadiness - As gun platform (Average = 50 %): 64 %
- Recoil effect (Restricted arc if above 1.00): 0.40
Seaboat quality (Average = 1.00): 1.28

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.480
Length to Beam Ratio: 9.72 : 1
'Natural speed' for length: 27.47 kts
Power going to wave formation at top speed: 58 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 32.50 degrees
Stern overhang: 3.28 ft / 1.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 34.45 ft / 10.50 m
- Forecastle (25 %): 24.61 ft / 7.50 m
- Mid (60 %): 24.61 ft / 7.50 m
- Quarterdeck (20 %): 14.76 ft / 4.50 m
- Stern: 14.76 ft / 4.50 m
- Average freeboard: 22.64 ft / 6.90 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 95.0 %
- Above water (accommodation/working, high = better): 152.9 %
Waterplane Area: 23,064 Square feet or 2,143 Square metres
Displacement factor (Displacement / loading): 127 %
Structure weight / hull surface area: 110 lbs/sq ft or 539 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.03
- Longitudinal: 2.31
- Overall: 1.12
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent
Good seaboat, rides out heavy weather easily

Regards,
Adam

[eswube]

Lots of great looking designs here!
Maybe I'll add something during the wekeend as I have a certain (bit twisted) idea.

[Krakatoa]

That's looking a lot better B.B.
Might I suggest updating the funnels to maybe 2 instead of 3 and use something like the Amphions for straight ones, or if you want to try the angled ones as per the plan, use a Southampton/Belfast funnel. That would bring everything together into the same timespan, funnels, bridge, guns.

Apdsmith
In the real world the only ships with 6x8 are Kinugasa, Kako, York types. To get anything else in a similar size requires a light cruiser hull of similar size that you can upgrade/new build. The only thing to be wary of is to make sure your triple 6" turrets are big enough (or have enough space around them) to be replaced with the twin 8" turrets you have in mind.

[apdsmith]

Hi Krakatoa,

Thanks for the comment. The AU storyline would have the CL-30s (I still haven't decided the exact year) designed from the outset to take 203mm turrets for a relatively cheap upgrade, so they'll have too much space for the 149.1mm triples they ship with initially.

I'm also pondering some work on the engines - assuming that they're coming up on about 8 years service when they go for refit (and that they're the smallest turbo-electric ships NSWE operates) would it be feasible, while replacing the turrets, to replace the boilers, turbines and diesels with the higher-pressure stuff that the Kriegsmarine was experimenting with? On SpringSharp the gains are marginal - almost a knot at top speed, +300nm range - so I'm wondering if it's worth it, even if it's not such a big job as it would be on a geared turbine ship (the SpringSharp modelling indicates that this engine replacement would result in roughly 10% greater horsepower, so original motors would suffice with extra cooling?)

Oh, also, a further question. We already have many excellent parts sheets for both real life and Ashley's KM'46 AU. Does anybody want the stuff I'm making for NSWE on a parts sheet of it's own? On the face of it, I think it's a little redundant, but don't want to (effectively) take stuff away from people if somebody does want the stuff.

Regards,
Adam