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Saturday, January 4th 2020, 2:47am

Miracle Class

Hello everyone


Uff. Feels like ages since I finished this ship the last year, but somehow I keep forgotting it. And just when I remembered it, was far to late. But finally my heavy cruiser is here. When I looked the desing before publish it I realize of how much you have helped me. Thank you all. :)



Class Miracle, Hevy Cruiser laid down 1922


Displacement:
9.233 t light; 9.657 t standard; 10.788 t normal; 11.693 t full load


Dimensions: Length overall / water x beam x draught
617,97 ft / 590,55 ft x 59,06 ft x 19,69 ft (normal load)
188,36 m / 180,00 m x 18,00 m x 6,00 m


Armament:
8 - 8,00" / 203 mm guns (4x2 guns), 256,00lbs / 116,12kg shells, 1922 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
10 - 4,00" / 102 mm guns in single mounts, 32,00lbs / 14,51kg shells, 1922 Model
Quick firing guns in deck mounts
on side, evenly spread
8 - 1,50" / 38,1 mm guns (4x2 guns), 1,69lbs / 0,77kg shells, 1922 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
4 - 1,50" / 38,1 mm guns in single mounts, 1,69lbs / 0,77kg shells, 1922 Model
Dual purpose guns in deck mounts
on centreline, all amidships, all raised mounts - superfiring
24 - 0,99" / 25,1 mm guns (8x3 guns), 0,49lbs / 0,22kg shells, 1922 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 2.400 lbs / 1.089 kg
Shells per gun, main battery: 150


Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 4,72" / 120 mm 324,80 ft / 99,00 m 9,22 ft / 2,81 m
Ends: Unarmoured
Main Belt covers 85 % of normal length


- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 5,91" / 150 mm 1,18" / 30 mm 3,94" / 100 mm
2nd: 1,18" / 30 mm - -
3rd: 1,18" / 30 mm - -
4th: 1,18" / 30 mm 0,79" / 20 mm -
5th: 1,18" / 30 mm - -


- Armour deck: 3,94" / 100 mm, Conning tower: 3,94" / 100 mm


Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 61.043 shp / 45.538 Kw = 29,00 kts
Range 5.000nm at 18,00 kts
Bunker at max displacement = 2.036 tons


Complement:
529 - 688


Cost:
£2,359 million / $9,437 million


Distribution of weights at normal displacement:
Armament: 300 tons, 2,8 %
Armour: 2.828 tons, 26,2 %
- Belts: 606 tons, 5,6 %
- Torpedo bulkhead: 0 tons, 0,0 %
- Armament: 408 tons, 3,8 %
- Armour Deck: 1.773 tons, 16,4 %
- Conning Tower: 41 tons, 0,4 %
Machinery: 2.071 tons, 19,2 %
Hull, fittings & equipment: 4.014 tons, 37,2 %
Fuel, ammunition & stores: 1.556 tons, 14,4 %
Miscellaneous weights: 20 tons, 0,2 %


Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
15.836 lbs / 7.183 Kg = 61,9 x 8,0 " / 203 mm shells or 1,9 torpedoes
Stability (Unstable if below 1.00): 1,22
Metacentric height 3,3 ft / 1,0 m
Roll period: 13,7 seconds
Steadiness - As gun platform (Average = 50 %): 53 %
- Recoil effect (Restricted arc if above 1.00): 0,58
Seaboat quality (Average = 1.00): 1,06


Hull form characteristics:
Hull has low forecastle
Block coefficient: 0,550
Length to Beam Ratio: 10,00 : 1
'Natural speed' for length: 24,30 kts
Power going to wave formation at top speed: 52 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 40,00 degrees
Stern overhang: 16,40 ft / 5,00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 13,12 ft / 4,00 m
- Forecastle (20 %): 9,84 ft / 3,00 m (22,97 ft / 7,00 m aft of break)
- Mid (50 %): 22,97 ft / 7,00 m
- Quarterdeck (15 %): 9,84 ft / 3,00 m
- Stern: 9,84 ft / 3,00 m
- Average freeboard: 16,34 ft / 4,98 m
Ship tends to be wet forward


Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 84,6 %
- Above water (accommodation/working, high = better): 170,3 %
Waterplane Area: 24.339 Square feet or 2.261 Square metres
Displacement factor (Displacement / loading): 115 %
Structure weight / hull surface area: 109 lbs/sq ft or 532 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,99
- Longitudinal: 1,04
- Overall: 1,00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent




I also want to ask you something. Since the sim is on it's ending I'm not going to be able to enter on the sim. But when I reed about WesWorld2 I got prety exited. For that reason I started to read some ideas about that. I realaized abot how much debate there is about the investigation. Since I'm not a playe and I don't have any experiense I don't know how good are my ideas in that respect, but I think I have one good. Let me know if you want to hear it

2

Saturday, January 4th 2020, 6:53pm

Overall, this looks like a pretty nice little heavy cruiser design for the early 1920s. You're definitely improving as a Springsharp designer.

Here's just a few comments that I'd mention. I don't view any of them as major items.

Deck Armour
In a general sense, I've noticed that most of the designs you've posted feature extremely heavy deck armour - probably about twice the amount of historical contemporaries - and this ship is no exception. I went back to check numbers, and most of the heavy cruisers I'm familiar with would have deck armour in the 40mm to 60mm range.
- Duquesne-class (France): 30mm deck
- Pensacola-class (United States): 44mm maximum
- Furutaka-class (Japan): 35mm
- County-class (UK): 65mm maximum (on a box citadel, so it's not even a proper 'armour deck' in the sense used by Springsharp)
- Trento-class (Italy): 50mm maximum

Note that most of these vessels fit in the very earliest categories of heavy cruiser design, and most were rather lightly armoured as designers figured out what could, and could not, be done on the 10,000 ton limits. Also, in many of these cases, the deck thickness was not uniform, which Springsharp doesn't model.

I believe 100mm deck armour was more common on period battleships (ships such as the Hood, the QEs, etc). I will suggest dropping the deck armour to 60mm (which is going to be quite good for a ship of this era) and re-investing that weight savings elsewhere.

Guns
I see two things that I'd like to suggest taking a closer look at.

First, the secondary 4" battery is quite decent. However, with a total of ten guns in total (and five on each beam), those guns will be using a fairly sizeable "footprint" of your available deck area. I'd like to instead suggest that eight 4" guns (in two twin mounts on each side) might in fact be preferable to the ten singles. You'd lose one gun on each broadside, but the amount of deck area would improve. (The twin mount would take up more footprint than a single mount, but probably no more than 25% more than the single mounting.)

Second, I note that you have four single 1.5" anti-aircraft guns placed on the centerline amidships. In this position, their firing arcs would definitely be constrained heavily by virtue of being surrounded by funnels, masts, etc. I'd instead recommend that you place them in two raised twin mountings on "centerline, ends"; in this position they'd be superfiring over the raised 8" guns, and their arcs of fire would be somewhere on the order of 180-deg forward (or aft) or greater. If they remain amidships, their firing arcs would probably be 30-deg or so on each beam.

Speed
29 knots is acceptable but hardly competitive against most of this ship's contemporaries, most of which are able to do 31+ knots. I think that, if you make the deck armour changes and the freeboard changes (below), you should be able to wring another knot or two of speed out of this ship.

As a general notation, Springsharp penalizes higher speeds far more than it really should, however (the calculations work best for battleships and battlecruisers). Thus, for ships like cruisers and destroyers, Springsharp's horsepower calculations for speed start rising precipitously past 32-34 knots, to the point where SS2 destroyers may end up with 200% more horsepower than comparable ships in real life. It's less of a problem with cruisers, but it's still something to keep in mind.

Hull Form
A couple oddities I noted here.

There's some very... interesting stuff going on with the freeboard. The prow of the ship starts with 4m of freeboard, drops to 3m, and then rises precipitously to 7m; it then slopes back down to 3m. That leaves the forecastle rather low in comparison to the average freeboard (it's marked out on the sim) and would result in the ship taking water over the bows in heavy seas.

Without re-simming the ship myself, I can't offer precise numbers, but I'd suggest starting with the values:
- Stem: 6.5m
- Forecastle: 6.0m
- Mid (50 %): 5.5m
- Quarterdeck: 3.25m
- Stern: 3.25m

As I said, without simming it myself (I'm on the wrong computer for SS2) those figures are very rough, but I think they should get you above 1.00 seakeeping without changing your hull strength values too much.

Miscellaneous
Given the era, this ship probably ought to have a floatplane (or three) for scouting work. If that's the case, I'd figure on adding about 25 tons of miscellaneous weight for every floatplane embarked aboard.

3

Saturday, January 4th 2020, 10:13pm

Your calculations on the freeboard are completly perfect. It took me a while to implement everything, especially because of the speed. Maybe I am beeing to obsesive with the seakeeping, tring to let it in 1 as minimun. For that reason I didn't dare put the speed over 30 knot. With all of your advises I have learn a lot. Thank you.

Class Miracle, Hevy Cruiser laid down 1922

Displacement:
9.388 t light; 9.809 t standard; 10.949 t normal; 11.862 t full load

Dimensions: Length overall / water x beam x draught
620,26 ft / 599,38 ft x 59,06 ft x 19,69 ft (normal load)
189,06 m / 182,69 m x 18,00 m x 6,00 m

Armament:
8 - 8,00" / 203 mm guns (4x2 guns), 256,00lbs / 116,12kg shells, 1922 Model
Breech loading guns in turrets (on barbettes)
on centreline ends, evenly spread, 2 raised mounts - superfiring
8 - 4,00" / 102 mm guns (4x2 guns), 32,00lbs / 14,51kg shells, 1922 Model
Quick firing guns in deck mounts
on side, evenly spread
8 - 1,50" / 38,1 mm guns (4x2 guns), 1,69lbs / 0,77kg shells, 1922 Model
Dual purpose guns in deck mounts
on side, evenly spread
4 - 1,50" / 38,1 mm guns (2x2 guns), 1,69lbs / 0,77kg shells, 1922 Model
Anti-aircraft guns in deck mounts
on centreline, all aft, all raised mounts - superfiring
24 - 0,99" / 25,1 mm guns (8x3 guns), 0,49lbs / 0,22kg shells, 1922 Model
Anti-aircraft guns in deck mounts
on side, evenly spread
Weight of broadside 2.336 lbs / 1.060 kg
Shells per gun, main battery: 150

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 6,10" / 155 mm 360,89 ft / 110,00 m 9,22 ft / 2,81 m
Ends: Unarmoured
Main Belt covers 93 % of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 5,91" / 150 mm 1,97" / 50 mm 4,72" / 120 mm
2nd: 1,18" / 30 mm 0,79" / 20 mm -
3rd: 1,18" / 30 mm 0,79" / 20 mm -
4th: 1,18" / 30 mm 0,79" / 20 mm -
5th: 1,18" / 30 mm 0,79" / 20 mm -

- Armour deck: 2,76" / 70 mm, Conning tower: 3,94" / 100 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 69.980 shp / 52.205 Kw = 30,00 kts
Range 5.000nm at 18,00 kts
Bunker at max displacement = 2.053 tons

Complement:
534 - 695

Cost:
£2,471 million / $9,886 million

Distribution of weights at normal displacement:
Armament: 292 tons, 2,7 %
Armour: 2.613 tons, 23,9 %
- Belts: 855 tons, 7,8 %
- Torpedo bulkhead: 0 tons, 0,0 %
- Armament: 456 tons, 4,2 %
- Armour Deck: 1.259 tons, 11,5 %
- Conning Tower: 42 tons, 0,4 %
Machinery: 2.374 tons, 21,7 %
Hull, fittings & equipment: 4.039 tons, 36,9 %
Fuel, ammunition & stores: 1.562 tons, 14,3 %
Miscellaneous weights: 70 tons, 0,6 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
13.584 lbs / 6.161 Kg = 53,1 x 8,0 " / 203 mm shells or 1,7 torpedoes
Stability (Unstable if below 1.00): 1,21
Metacentric height 3,2 ft / 1,0 m
Roll period: 13,8 seconds
Steadiness - As gun platform (Average = 50 %): 50 %
- Recoil effect (Restricted arc if above 1.00): 0,48
Seaboat quality (Average = 1.00): 1,00

Hull form characteristics:
Hull has low quarterdeck
Block coefficient: 0,550
Length to Beam Ratio: 10,15 : 1
'Natural speed' for length: 24,48 kts
Power going to wave formation at top speed: 54 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 20,00 degrees
Stern overhang: 13,12 ft / 4,00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 21,33 ft / 6,50 m
- Forecastle (20 %): 19,69 ft / 6,00 m
- Mid (50 %): 18,04 ft / 5,50 m
- Quarterdeck (15 %): 10,66 ft / 3,25 m (11,48 ft / 3,50 m before break)
- Stern: 10,66 ft / 3,25 m
- Average freeboard: 16,49 ft / 5,03 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 92,1 %
- Above water (accommodation/working, high = better): 146,8 %
Waterplane Area: 24.703 Square feet or 2.295 Square metres
Displacement factor (Displacement / loading): 112 %
Structure weight / hull surface area: 108 lbs/sq ft or 526 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1,02
- Longitudinal: 1,00
- Overall: 1,00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is excellent

4

Monday, February 10th 2020, 5:43am

I like this design though as a personal preference a few more knots speed would be useful. You could likely do this by reducing the deck armor another 10mm and/or reduce the conning tower armor slightly but you'd be robbing Peter to pay Paul, you still have a decent design without modifications. That said you could toy around with the design a bit as you have 500-700 tons to play with if you plan on keeping the design under 10,000 tons.

Nicely done!