"Real World" Ship SIMs

[Kaiser Kirk]

Rather than keep cluttering the tech thread, I thought I'd put these here.

The goal is to model real-world ships as close as we can, to see what can be done within the confines of our current rules, and where we might consider tech for help.

Others who have reference material that gives them hints like block coefficient, width of belt, tons of fuel oil, etc ... feel free to add.

Others, feel free to comment :)

[Kaiser Kirk]

So this is my attempt at the HMS Aresthusa, exploring where the 0.75 cap should be.

This illustrates Option #3.

It seems close enough to the real ship to be a plausible SIM,
and would suggest the tech support a 0.75 at 5,000t allowance

Option 1 - use SHP to determine BC
The supporting information on the ship is problematic.
32.5knts with 64,000shp allow determining the BC.
1325 tons of fuel oil is listed....and for the British fleet speed of 14knots
works out to 10,230nm.

The range is a bit irrelevant, the tons of fuel oil should be right
and would effect light displacement and standard displacement.

world-war.co.uk  puts the tonnage at 5220 std, 6665 full load.

With this fuel loading it has 5229 Normal- maybe a mix up
but 4493 Std. and 4282 Light. So way off. .

And the Comp Str. Does not work out.

option 2- use alternative range
Elsewhere is listed 5300nm at 13 knots-
But that pushes the standard displacement  to 4892-still low, and max disp. is far to low.

The Comp Str. is near correct at 0.73.


option 3- adjust BC to get right 5220 Std displacement, freeboard for 1.0+, then 1325 oil fuel

This gets us near the right max disp, and near the right standard,
while using the right fuel loading, and a reasonable range result.

5300nm & 18knots would take 1387tons fuel. -62 tons more.
Very close.

My guess is a handwritten 5300@18 was mis-copied at 5300@18.

The SHP is too high now, 72,000 vs. 64,000. 
A small Transom nearly fixes things, 0.75comp str, 1.0 seakeeping
SHP 66,374 instead of 64,000 ...but all the plans show a cruiser stern.

Perhaps it only made 32 on trials at overload of 72,000,
while 31.1 knots gets 64,000shp for normal speed?
Comp St. is 0.79 for 31.1

Aresthusa, Enter country Enter ship type laid down 1934

Displacement:
    4,939 t light; 5,164 t standard; 5,934 t normal; 6,550 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
    (480.00 ft / 480.00 ft) x 51.00 ft x (14.00 / 15.20 ft)
    (146.30 m / 146.30 m) x 15.54 m  x (4.27 / 4.63 m)

Armament:
      6 - 6.00" / 152 mm 50.0 cal guns - 114.33lbs / 51.86kg shells, 200 per gun
      Quick firing guns in deck and hoist mounts, 1934 Model
      3 x 2-gun mounts on centreline ends, majority forward
        1 raised mount - superfiring
      8 - 4.00" / 102 mm 45.0 cal guns - 32.28lbs / 14.64kg shells, 200 per gun
      Dual purpose guns in deck and hoist mounts, 1934 Model
      4 x 2-gun mounts on sides, evenly spread
      16 - 0.50" / 12.7 mm 90.0 cal guns - 0.07lbs / 0.03kg shells, 2,000 per gun
      Anti-air guns in deck mounts, 1934 Model
      4 x 4 row quad mounts on side ends, evenly spread
        4 raised mounts
      Weight of broadside 945 lbs / 429 kg

Armour:
  - Belts:        Width (max)    Length (avg)        Height (avg)
    Main:    2.25" / 57 mm    182.00 ft / 55.47 m    18.36 ft / 5.60 m
    Ends:    Unarmoured
    Upper:    2.25" / 57 mm      50.85 ft / 15.50 m    12.71 ft / 3.87 m
      Main Belt covers 58 % of normal length
      Main belt does not fully cover magazines and engineering spaces

  - Gun armour:    Face (max)    Other gunhouse (avg)    Barbette/hoist (max)
    Main:    1.00" / 25 mm    1.00" / 25 mm        1.00" / 25 mm
    2nd:    1.00" / 25 mm          -                  -
    3rd:    1.00" / 25 mm          -                  -

  - Armoured deck - single deck:
    For and Aft decks: 1.28" / 33 mm
    Forecastle: 1.00" / 25 mm  Quarter deck: 1.00" / 25 mm

Machinery:
    Oil fired boilers, steam turbines,
    Geared drive, 4 shafts, 72,156 shp / 53,829 Kw = 32.00 kts
    Range 5,300nm at 18.00 kts
    Bunker at max displacement = 1,387 tons

Complement:
    337 - 439

Cost:
    £2.755 million / $11.019 million

Distribution of weights at normal displacement:
    Armament: 280 tons, 4.7 %
      - Guns: 280 tons, 4.7 %
    Armour: 913 tons, 15.4 %
      - Belts: 453 tons, 7.6 %
      - Armament: 46 tons, 0.8 %
      - Armour Deck: 414 tons, 7.0 %
    Machinery: 2,076 tons, 35.0 %
    Hull, fittings & equipment: 1,563 tons, 26.3 %
    Fuel, ammunition & stores: 995 tons, 16.8 %
    Miscellaneous weights: 107 tons, 1.8 %
      - On freeboard deck: 54 tons
      - Above deck: 53 tons

Overall survivability and seakeeping ability:
    Survivability (Non-critical penetrating hits needed to sink ship):
      3,735 lbs / 1,694 Kg = 34.6 x 6.0 " / 152 mm shells or 0.8 torpedoes
    Stability (Unstable if below 1.00): 1.31
    Metacentric height 2.9 ft / 0.9 m
    Roll period: 12.5 seconds
    Steadiness    - As gun platform (Average = 50 %): 51 %
            - Recoil effect (Restricted arc if above 1.00): 0.39
    Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
    Hull has rise forward of midbreak,
      a ram bow and a cruiser stern
    Block coefficient (normal/deep): 0.606 / 0.616
    Length to Beam Ratio: 9.41 : 1
    'Natural speed' for length: 21.91 kts
    Power going to wave formation at top speed: 64 %
    Trim (Max stability = 0, Max steadiness = 100): 50
    Bow angle (Positive = bow angles forward): 0.00 degrees
    Stern overhang: 0.00 ft / 0.00 m
    Freeboard (% = length of deck as a percentage of waterline length):
                Fore end,    Aft end
      - Forecastle:    20.00 %,  27.00 ft / 8.23 m,  24.00 ft / 7.32 m
      - Forward deck:    38.00 %,  24.00 ft / 7.32 m,  22.00 ft / 6.71 m
      - Aft deck:    29.50 %,  14.00 ft / 4.27 m,  14.00 ft / 4.27 m
      - Quarter deck:    12.50 %,  14.00 ft / 4.27 m,  14.00 ft / 4.27 m
      - Average freeboard:        19.66 ft / 5.99 m

Ship space, strength and comments:
    Space    - Hull below water (magazines/engines, low = better): 129.0 %
        - Above water (accommodation/working, high = better): 194.0 %
    Waterplane Area: 18,005 Square feet or 1,673 Square metres
    Displacement factor (Displacement / loading): 97 %
    Structure weight / hull surface area: 59 lbs/sq ft or 286 Kg/sq metre
    Hull strength (Relative):
        - Cross-sectional: 0.64
        - Longitudinal: 1.34
        - Overall: 0.69
    Caution: Hull subject to strain in open-sea
    Cramped machinery, storage, compartmentation space
    Excellent accommodation and workspace room

Warning: Beam between bulkheads too wide

The Aresthusa is my trial at what displacement the 0.75 / 0.9 break should be.

Option 1 - use SHP to determine BC
The supporting information on the ship is problematic.
32.5knts with 64,000shp allow determining the BC.
1325 tons of fuel oil is listed....and for the British fleet speed of 14knots
works out to 10,230nm.

The range is a bit irrelevant, the tons of fuel oil should be right
and would effect light displacement and standard displacement.

world-war.co.uk  puts the tonnage at 5220 std, 6665 full load.

With this fuel loading it has 5229 Normal- maybe a mix up
but 4493 Std. and 4282 Light. So way off. .

And the Comp Str. Does not work out.

option 2- use alternative range
Elsewhere is listed 5300nm at 13 knots-
But that pushes the standard displacement  to 4892-still low, and max disp. is far to low.

The Comp Str. is near correct at 0.73.


option 3- adjust BC to get right 5220 Std displacement, freeboard for 1.0+, then 1325 oil fuel

This gets us near the right max disp, and near the right standard,
while using the right fuel loading, and a reasonable range result.

5300nm & 18knots would take 1387tons fuel. -62 tons more.
Very close.

My guess is a handwritten 5300@18 was mis-copied at 5300@18.

The SHP is too high now, 72,000 vs. 64,000. 
A small Transom nearly fixes things, 0.75comp str, 1.0 seakeeping
SHP 66,374 instead of 64,000 ...but all the plans show a cruiser stern.

Perhaps it only made 32 on trials at overload of 72,000,
while 31.1 knots gets 64,000shp for normal speed?
Comp St. is 0.79 for 31.1






The Armor scheme is quite problematic.
The 1" deck/gun protection is clear.
The magazines had 1-3" protection... ok Magazine box, but how much 1", how much 3" ?

The plan shows the deck raised amidships and a big patch of 2.25" belt armor there. About the same height as draft
amid ships, and with a strake aft, but not all along the waterline.
I wound up taking a image to Paint and counting the armor area to
figure the bet area, splitting the two strakes to the main and upper belts.


SS gives a Machinery length of 426.20 ft.
We know that destroyers, and over-engined ships like the Lexington BCs, had engines above the WL.

I am guessing this was the case here, that the engines extended above the WL,
and so they put a patch of armor on the sides and raised the armor deck 2 levels.
While fore/aft the deck was a protective deck and the  magazines were under the protective deck with 3" sides

So you wind up with the Armor belt being about 16ft high forward, 8ft aft, for an average of 125


Misc Wt
28    FC
25    LR Radio

5t    Paravanes
24    2TT3 21" 34

20t  Floatplane
5t    Catapult


Armor :
308 armor deck 1"
71  magazine box 3"

[Logi]

Springsharp uses Holtren-Mennen to predict resistance and propulsive power. H&M doesn't really work for Fn > 0.45, LB > 9.5, or Cp < 0.55. As designed, Aresthusa is pretty close to the limit there with Fn 0.4345, Cp,est ~ 0.62, LB 9.41.

In general, it's not good for small, slender, and fast vessels. Which is why it basically doesn't work for destroyers and barely works here for Aresthusa. H&M is also for displacement-mode ships and I suspect destroyers and light cruisers vastly exceeding hull speed were operating in semi-displacement mode instead - although the produced lift was small. Many destroyers had rather V-shaped bottoms after all due to the fineness of their lines.

Here the hull speed is 29.36 kn and so the mismatch wouldn't be as large. I don't remember how SS3 calculated the transom stern effect, but I'm inclined to think it was a hack given it's not well understood even today and side-stepped via CFD.

So I would understand the use of "transom stern" in SS as a way to make up for H&M's shortcomings rather than an indication of whether the hull actually uses a transom stern.

[Kaiser Kirk]

Interesting Logi, I had no idea about the hull equations differing like that.
Actually saves me some planned work as I was going to try to sim some USN DD designs and see how they fit out system.

For Brooklyn, the 'transom, small' seems to produce good results,
as it would with this Aresthusa.

However, one of the key points to me is that this historical design
does not work under our current 0.75@3000 or 0.9@8000 tech points

I'd like to find another vessel in this tonnage range with good info and validate that, or perhaps use some of the USN design studies for smaller cruisers.

Meanwhile I'm still trying to figure out if Brooklyn's belt was the magazine box & thin side over machinery of the early USN cruisers, or the magazine box plus 5" belt you find later. Friedman's just not terribly clear, sounds like the change was made with the New Orlean's class, in which case the latter. Now home, I can check some other sources.

[TacCovert4]

Overall I'm content with the cruiser rules.  I would like small transom to be added for DDs as that was becoming a thing circa WW1

[Logi]

I tried doing a sim based on Fletcher based on Friedman's book. The freeboard is based on Friedman's drawing and the reported draft + depth. Had to use "Transom stern - large" to get it to somewhat work (small transom only yields 0.46 strength), but some issues remain:

1. "Minimum main belt length to cover machinery and magazines is excessive at 406.17 ft. There are no warnings in the report simply because the current design doesn't use belt armor.

2. Sea-keeping is excessively low even for a wet destroyer. But this is an issue we've known about since SS2.

3. Lightship is overweight; this seems to be true of all designs not just DDs. In this case it seems to be mostly from over-reported machinery weight. SS3 has it at 1382 tons vs 862.4~897.3 (dry) in Friedman. If this difference is subtracted from SS3's reported lightship, the discrepancy narrows from 532~435 (overweight) to 12.4 ~ -49.7.

4. Its difficult to simulate the box over machinery & magazines. It's supposed to be 30# (0.75") on the sides and 20# (0.5") on the deck. Can't really simulate the sides as is; would need some way to pick a good midway point to simulate this. If I pick 30# instead of 20# for the sides, the composite strength drops to 0.47 even without FC/QD deck armors.

In the text section, Friedman mentions the 5" only have 2100 rounds in total even though it's listed as 600 per gun. He also mentions "4 reloads" for the torpedoes but I'm not sure if its 4 sets or just 4. Here I assumed it was sets.

So ultimately the issue is the resistance/propulsive model SS3 uses (H&M). At least in Fletcher's case the other inaccuracies in estimation mostly cancel out.

Fletcher, USN DD laid down 1941

Displacement:
   2,400 t light; 2,532 t standard; 2,806 t normal; 3,026 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (376.50 ft / 369.00 ft) x 39.67 ft x (13.45 / 14.21 ft)
   (114.76 m / 112.47 m) x 12.09 m  x (4.10 / 4.33 m)

Armament:
      5 - 5.00" / 127 mm 38.0 cal guns - 59.33lbs / 26.91kg shells, 420 per gun
     Dual purpose guns in deck and hoist mounts, 1941 Model
     5 x Single mounts on centreline ends, majority aft
      2 raised mounts - superfiring
      2 - 1.57" / 40.0 mm 56.0 cal guns - 2.12lbs / 0.96kg shells, 2,000 per gun
     Anti-air guns in deck mount, 1941 Model
     1 x Twin mount on centreline, forward deck aft
      6 - 0.79" / 20.0 mm 70.0 cal guns - 0.26lbs / 0.12kg shells, 2,000 per gun
     Machine guns in deck mounts, 1941 Model
     2 x Single mounts on sides, aft deck centre
     2 x Twin mounts on sides, forward deck centre
      2 raised mounts
      Weight of broadside 302 lbs / 137 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.13" / 3 mm   0.13" / 3 mm      0.13" / 3 mm

   - Box over machinery & magazines:
   0.50" / 13 mm
   Forecastle: 0.50" / 13 mm  Quarter deck: 0.50" / 13 mm

   - Conning towers: Forward 0.75" / 19 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 60,263 shp / 44,956 Kw = 35.10 kts
   Range 4,364nm at 15.00 kts
   Bunker at max displacement = 494 tons

Complement:
   192 - 250

Cost:
   £1.868 million / $7.471 million

Distribution of weights at normal displacement:
   Armament: 74 tons, 2.6 %
      - Guns: 74 tons, 2.6 %
   Armour: 229 tons, 8.2 %
      - Armament: 4 tons, 0.2 %
      - Armour Deck: 221 tons, 7.9 %
      - Conning Tower: 3 tons, 0.1 %
   Machinery: 1,383 tons, 49.3 %
   Hull, fittings & equipment: 491 tons, 17.5 %
   Fuel, ammunition & stores: 406 tons, 14.5 %
   Miscellaneous weights: 223 tons, 7.9 %
      - On freeboard deck: 216 tons
      - Above deck: 7 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     544 lbs / 247 Kg = 8.7 x 5.0 " / 127 mm shells or 0.4 torpedoes
   Stability (Unstable if below 1.00): 1.08
   Metacentric height 1.4 ft / 0.4 m
   Roll period: 13.9 seconds
   Steadiness   - As gun platform (Average = 50 %): 37 %
         - Recoil effect (Restricted arc if above 1.00): 0.23
   Seaboat quality  (Average = 1.00): 0.30

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and large transom stern
   Block coefficient (normal/deep): 0.499 / 0.509
   Length to Beam Ratio: 9.30 : 1
   'Natural speed' for length: 22.05 kts
   Power going to wave formation at top speed: 72 %
   Trim (Max stability = 0, Max steadiness = 100): 91
   Bow angle (Positive = bow angles forward): 19.00 degrees
   Stern overhang: 0.55 ft / 0.17 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  20.17 ft / 6.15 m,  14.79 ft / 4.51 m
      - Forward deck:   30.00 %,  14.79 ft / 4.51 m,  9.41 ft / 2.87 m
      - Aft deck:   35.00 %,  9.41 ft / 2.87 m,  7.61 ft / 2.32 m
      - Quarter deck:   15.00 %,  7.61 ft / 2.32 m,  7.61 ft / 2.32 m
      - Average freeboard:      11.14 ft / 3.39 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 169.4 %
      - Above water (accommodation/working, high = better): 102.2 %
   Waterplane Area: 10,132 Square feet or 941 Square metres
   Displacement factor (Displacement / loading): 73 %
   Structure weight / hull surface area: 35 lbs/sq ft or 172 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.51
      - Longitudinal: 0.68
      - Overall: 0.52
   Cramped machinery, storage, compartmentation space
   Adequate accommodation and workspace room
   Caution: Lacks seaworthiness - very limited seakeeping ability

Geared +10% range = 4800 nm @ 15 kn

7t: FCS
40t: 2x5 21" torps
160t: 4 sets of reloads for 21" torps

2t: 2 DC throwers
14t: 28 DCs + 14 mobilization allowance

From archive.org/embed/usdestroyersillu0000frie


Scheme 10-C generally being the Fletcher

[TacCovert4]

The issue at play with the engine weight is most likely engines are presumed to be standard pressure stuff.   While the US was using high pressure plants.

A solution might be to have a powerplant tech for lighter machinery that gives a 15 to 20% increase to power output, shown as maximum speed, due to high pressure machinery.  This would only apply to steam turbines.

[Kaiser Kirk]

Cruiser rules
The idea of trying 'RW' ships is to see if our Rule set works vs. SS.
Something like Aresthusa isn't possible under our rules, and to me that's a problem. Likewise there's the issue of cruisers using turrets, more welding, high stresses accepted on the hulls, more destroyer like machinery...all of which should reduce weights, and adopted in the 1920s-30s, so I'm curious if our 0.9 threshold should move.

Transom
While there were some designs with transoms in the 1920s, they seem to have been really adopted in the 1930s by some nations. Seems a difference between theory and adoption, and also that they pay off more in the high speed ranges not used much WWI & Interwar.

Using Brooklyn as evidence, for the tech to be available in 1934, a 1932 Cruiser tech would need to be available.


Fletcher Class
I've used some British interwar destroyers as base designs before, my 'Pirate' grew out of the 'R' Class, but never have tried USN WW2 designs.
I do have Friedman's book, but have not found the reading time to get far into it.

Looks like perhaps I should borrow that hull form :)

1.Belt Length - Walter (Roojen) and I explored that early. The volume is the underwater hull, probably comprising the entire citadel area.

My understanding was not all Destroyer engines wholey fit below the waterline, making them more difficult to protect.

Further, destroyers were built with few redundant systems, the machinery used was lightweight, more prone to breaking and high PSI. So the volume is likely off.

Walter's math said that up to 133% would be the volume below WL, so we used that as the design guideline for where protective decks work.

2. Snip did some work on Destroyer seakeeping, and decided 0.76 was plenty.
In the Caicos war he did loose a couple 0.67 seakeeping in a hurricane.

Some comments in US Destroyers, and I think elsewhere, seem to indicate that the normal top speed of a DD was 3-4 knots under trials, and that they really could only hit those in low sea states. Basically, reported Destroyer top speeds are not indicative of their operational top speeds.
I still aim for 1.0.

3. The Box choice in SS is ~3m(3.5?) high as I remember.
  I expect the path here is to sim the belt as 0.25" and specify the bulkheads of the box are 0.75".


4. There's discussion in US Cruisers & Destroyers on how the original shell loadouts were ~200, with room for ~400, but as the war went on they found they needed more. The text here talks about some designs with 480 and some with 600.
They may have decided to plan 'mobilization' space for 600, but plan on less for
other reasons such as meeting a chosen speed.

5. Hmm, so apparently Large Transom should be in the conversation for Destroyers.

*argh* almost lost another post.

[TacCovert4]

Maybe Small Transom on ships under 10,000t is a 1933 or 34 tech, and Large Transom for Ships under 3001 tons is a 1936 or 38 tech?

[Kaiser Kirk]

Maybe Small Transom on ships under 10,000t is a 1933 or 34 tech, and Large Transom for Ships under 3001 tons is a 1936 or 38 tech?

Unless we have further Destroyer type things to 'unlock', consolidating all transoms on Cruisers is my preference.

Doing as you suggest and splitting them Large/Small seems reasonable,
perhaps the 3000t limit as the breakpoint.

An upper tonnage limit does not seem required.
Both Alaska and Baltimore appear to have transom sterns, and I could swear I read it was considered for the Nelson class (where it would not do much).

Sadly I've got some other pressing things, so I am not playing with ship designs for a bit, or reading books. My efforts at Brooklyn require reading a tad more, and I think Baltimore is close to done. I want to try some more small cruisers, or perhaps the French Super-Destroyers, and I haven't started on revisiting the Colossus class.

[Kaiser Kirk]

This was a ship I had mostly completed- the USS Baltimore.
The design seems to use a transom, which makes the numbers work out pretty well.

On the Brooklyn, I am still trying to decide if it mimiced New Orleans's mag box + thin belt, or the later ships mag box + heavy belt. Baltimore is clearly past that change,
and I strongly suspect Brooklyn IS that change point.

But really I shouldn't even be pausing to post this, I should be doing other things, but procrastination is one of the few things I'm really really good at !

USS Baltimore, USA Heavy Cruiser laid down 1941

Displacement:
   14,391 t light; 15,291 t standard; 16,942 t normal; 18,263 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (674.32 ft / 664.00 ft) x 70.81 ft x (24.02 / 25.43 ft)
   (205.53 m / 202.39 m) x 21.58 m  x (7.32 / 7.75 m)

Armament:
      9 - 8.00" / 203 mm 55.0 cal guns - 334.99lbs / 151.95kg shells, 150 per gun
     Breech loading guns in turret on barbette mounts, 1941 Model
     3 x 3-gun mounts on centreline ends, majority forward
      1 raised mount - superfiring
      12 - 5.00" / 127 mm 38.0 cal guns - 55.12lbs / 25.00kg shells, 500 per gun
     Dual purpose guns in deck and hoist mounts, 1941 Model
     4 x 2-gun mounts on side ends, evenly spread
     2 x 2-gun mounts on centreline ends, evenly spread
      2 double raised mounts
      48 - 1.57" / 40.0 mm 56.3 cal guns - 2.05lbs / 0.93kg shells, 2,000 per gun
     Anti-air guns in deck mounts, 1941 Model
     12 x Quad mounts on sides, evenly spread
      6 raised mounts
      28 - 0.79" / 20.0 mm 70.0 cal guns - 0.26lbs / 0.12kg shells, 4,000 per gun
     Breech loading guns in deck mounts, 1941 Model
     28 x Single mounts on sides, evenly spread
      28 raised mounts
      Weight of broadside 3,782 lbs / 1,716 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   5.25" / 133 mm   431.60 ft / 131.55 m   10.50 ft / 3.20 m
   Ends:   2.50" / 64 mm   232.38 ft / 70.83 m   10.50 ft / 3.20 m
     Main Belt covers 100 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   8.00" / 203 mm   3.00" / 76 mm      6.30" / 160 mm
   2nd:   1.00" / 25 mm   0.75" / 19 mm      0.75" / 19 mm
   3rd:   0.13" / 3 mm         -               -
   4th:   0.13" / 3 mm         -               -

   - Armoured deck - single deck:
   For and Aft decks: 3.30" / 84 mm
   Forecastle: 2.50" / 64 mm  Quarter deck: 2.50" / 64 mm

   - Conning towers: Forward 6.50" / 165 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 4 shafts, 120,009 shp / 89,526 Kw = 33.06 kts
   Range 10,000nm at 15.00 kts
   Bunker at max displacement = 2,972 tons

Complement:
   742 - 965

Cost:
   £8.033 million / $32.134 million

Distribution of weights at normal displacement:
   Armament: 1,055 tons, 6.2 %
      - Guns: 1,055 tons, 6.2 %
   Armour: 3,888 tons, 22.9 %
      - Belts: 1,211 tons, 7.1 %
      - Armament: 655 tons, 3.9 %
      - Armour Deck: 1,930 tons, 11.4 %
      - Conning Tower: 92 tons, 0.5 %
   Machinery: 3,171 tons, 18.7 %
   Hull, fittings & equipment: 5,933 tons, 35.0 %
   Fuel, ammunition & stores: 2,551 tons, 15.1 %
   Miscellaneous weights: 343 tons, 2.0 %
      - On freeboard deck: 95 tons
      - Above deck: 248 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     23,567 lbs / 10,690 Kg = 92.1 x 8.0 " / 203 mm shells or 2.4 torpedoes
   Stability (Unstable if below 1.00): 1.10
   Metacentric height 3.6 ft / 1.1 m
   Roll period: 15.8 seconds
   Steadiness   - As gun platform (Average = 50 %): 51 %
         - Recoil effect (Restricted arc if above 1.00): 0.57
   Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
   Hull has a flush deck,
     a straight bulbous bow and small transom stern
   Block coefficient (normal/deep): 0.525 / 0.535
   Length to Beam Ratio: 9.38 : 1
   'Natural speed' for length: 27.68 kts
   Power going to wave formation at top speed: 57 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 16.00 degrees
   Stern overhang: 2.00 ft / 0.61 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  29.00 ft / 8.84 m,  25.00 ft / 7.62 m
      - Forward deck:   30.00 %,  25.00 ft / 7.62 m,  21.00 ft / 6.40 m
      - Aft deck:   35.00 %,  21.00 ft / 6.40 m,  19.00 ft / 5.79 m
      - Quarter deck:   15.00 %,  19.00 ft / 5.79 m,  19.00 ft / 5.79 m
      - Average freeboard:      22.07 ft / 6.73 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 82.2 %
      - Above water (accommodation/working, high = better): 180.3 %
   Waterplane Area: 32,836 Square feet or 3,051 Square metres
   Displacement factor (Displacement / loading): 122 %
   Structure weight / hull surface area: 129 lbs/sq ft or 631 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.97
      - Longitudinal: 1.36
      - Overall: 1.00
   Excellent machinery, storage, compartmentation space
   Excellent accommodation and workspace room

Displacements in US Cruisers is confusing, I think because the summary table combines data from different vessels in the series.

Full load is given as 17031, which likely lines up with the "Normal" of 16942.

Standard is listed but specified as 1/2 stores and 5gal water per man, which is not the Standard of the treaty.

There is a Light ship of 12576-13040.

I dunno- Length, beam, draft, BC, range are all right. #shells/gun come from Navweaps.
Freeboard is calculated from "hull depth" listed.

With Small Transom, 120,000shp yields the 33 knot speed typically cited.
Design speed was 34 knots, but trial speed was 33 knots.

trial was 133,649 for 33knots
design was 120,000 for 33.5 knots
CA29 made 32.85knts  at 118536ihp at 16570tons
Pittsburgh did 33knts at 16200,
original trial disp 15800-15900

US cruisers gives 10,000/15 as design, and 7900/15 as service.


Armor :
Belt
The belt is very hard to figure out.
The earlier USN cruiser belts were 9.5ft high ...I think.
I believe they were deepened, but I can't find to what.
Based on beam, this defaults to 10.1 feet.

Aslo this one tapered from 6" to 3"
Further, the USN took to using thinner belts abreast the magazine, but
backed by what seems to be a magazine box.

So I am going to model this as 10.5 feet high,
with the last 2 feet tapering down from 6" to 3"  adjacent to machinery
and the last 2 feet tapering down from 3" to 2" adjacent to magazines
all of which makes 4 belt sections.
And with the belt over magazines and that over machinery seperate.


91.14 feet for Magazine Belt
340.46 feet for Machinery Belt

150t   91.14ft x 8.5' @ 3"
29t     91.14ft x 2' @ 3->2"

686    304.46 x 8.5' @ 6"
121   304.46 x 2' @ 6->3"
-----
986t
= average thickness 5.25"

Deck
1531t        2.5" Deck
295t          2.5" box over magazines
100t          1" floor under magazines (from US cruisers)
-------
1926

Weight Budgeted : 1930t

Miscellaneous Weight

AD
98t   Fire Control
25t     LR Radio
125t   5 Radars

OD
5t  Paravanes
80t  4x Scout floatplanes, stern hanger
10t  2x Stern CATs

[Kaiser Kirk]

The Baltimore above demonstrates a couple points
- doesn't need lower than 1.0
- still used small transom
- works out ok with our Misc weight 'guesses'.

The Brooklyn was difficult to model.
This is the USS Brooklyn class.
Getting it 'right' is somewhat critical, as it would mark
- turrets in cruisers
- 0.9 comp hull @10,000 tons
- which transom stern to use. (Small)

The Armor has been the hardest part.
The New Orleans Class had a Magazine Boxes, and then a thin belt.
Unlike the preceeding classes the Magazine boxes on the New Orleans were not above the waterline.

However, most resources give a 5" belt for the Brooklyn class, which gives a composite strength of 0.90, but other speak of mixed armor.
The heavier belt certainly seems to have been true of the cruiser designs that followed after this class, with the magazine box retained for additional armor.

The www.navygeneralboard.com  page states
"Armor protection was light, though not non-existent. The main armored belt was 5" (127mm) over the machinery with lighter armor of 2" (51mm) over the 6" magazines. It might seem odd to have a lighter belt over the magazines but the cruisers had thicker 6" (152mm) protecting the barbettes of the main armament.  Deck armor was about 2" (51mm) at its thickest.  The turrets featured armor of 6.5" (165mm) on the faceplates and 2" (51mm) roofs."

That description makes sense if they were considering the Magazine box thickness as the 'barbettes',
and then a 2" belt abutting that magazine armor. 

If that is the case with Brooklyn, then a magazine box & 2" belt abreast, but 5" elsewhere  would SIM the ship
which it does for a composite strength of 0.91

US Cruisers says that it is 1" less at the magazines than the New Orleans Class. The New Orleans class were 5.75" at the magazines, so a Brooklyn should be 4.75".

A 2" Belt and Deck with a magazine box adding 2.75" would bring it up to 4.75".

So that's how it's been modeled.

Belt Armor
88t    2" belt Belt adjacent to Magazine : 65ft
656t  5" Belt over Machinery & for flotation : 293ft (325ft)
-----
744

Deck Armor
83t   2.75" magazine box
64t   1.5" deck forward of magazines
870t  2".0 deck Citadel & Aft
----
1017


Light Ship should be 9456, inc 164t ballast, or 9292t
Standard was 9799.7,
normal 113799

This sim is
9792  light
10263 standard
11700 normal

*SHP is the nominal 100,000, not the 101 gained on trials.
Design speed was 32.5knts
111,000SHP is needed to get the 33.7 the ship got on trials,
but that is undoubtably light ship, so riding higher in the water for less draft.

USS Brooklyn, United states Cruiser laid down 1934

Displacement:
   9,792 t light; 10,263 t standard; 11,700 t normal; 12,849 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (607.74 ft / 600.00 ft) x 61.60 ft x (21.47 / 23.04 ft)
   (185.24 m / 182.88 m) x 18.78 m  x (6.54 / 7.02 m)

Armament:
      15 - 6.00" / 152 mm 47.0 cal guns - 112.35lbs / 50.96kg shells, 200 per gun
     Quick firing guns in turret on barbette mounts, 1934 Model
     5 x Triple mounts on centreline ends, majority forward
      2 raised mounts - superfiring
      8 - 5.00" / 127 mm 25.0 cal guns - 53.99lbs / 24.49kg shells, 200 per gun
     Anti-air guns in deck mounts, 1934 Model
     4 x Single mounts on sides, forward deck aft
      8 - 0.50" / 12.7 mm 90.0 cal guns - 0.07lbs / 0.03kg shells, 5,000 per gun
     Breech loading guns in deck mounts, 1934 Model
     8 x Single mounts on sides, evenly spread
      8 raised mounts
      Weight of broadside 2,118 lbs / 961 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   4.87" / 124 mm   390.00 ft / 118.87 m   9.50 ft / 2.90 m
   Ends:   Unarmoured
     Main Belt covers 100 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   6.50" / 165 mm   2.00" / 51 mm      5.50" / 140 mm
   2nd:   0.13" / 3 mm   0.13" / 3 mm            -
   3rd:   0.13" / 3 mm         -               -

   - Armoured deck - single deck:
   For and Aft decks: 2.21" / 56 mm
   Forecastle: 1.50" / 38 mm  Quarter deck: 2.00" / 51 mm

   - Conning towers: Forward 5.00" / 127 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 4 shafts, 95,697 shp / 71,390 Kw = 32.82 kts
   Range 5,350nm at 20.00 kts
   Bunker at max displacement = 2,586 tons

Complement:
   562 - 731

Cost:
   £4.452 million / $17.806 million

Distribution of weights at normal displacement:
   Armament: 447 tons, 3.8 %
      - Guns: 447 tons, 3.8 %
   Armour: 2,407 tons, 20.6 %
      - Belts: 744 tons, 6.4 %
      - Armament: 591 tons, 5.1 %
      - Armour Deck: 1,017 tons, 8.7 %
      - Conning Tower: 56 tons, 0.5 %
   Machinery: 2,753 tons, 23.5 %
   Hull, fittings & equipment: 4,000 tons, 34.2 %
   Fuel, ammunition & stores: 1,908 tons, 16.3 %
   Miscellaneous weights: 185 tons, 1.6 %
      - On freeboard deck: 115 tons
      - Above deck: 70 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     14,659 lbs / 6,649 Kg = 135.7 x 6.0 " / 152 mm shells or 1.8 torpedoes
   Stability (Unstable if below 1.00): 1.14
   Metacentric height 3.1 ft / 0.9 m
   Roll period: 14.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 51 %
         - Recoil effect (Restricted arc if above 1.00): 0.55
   Seaboat quality  (Average = 1.00): 1.22

Hull form characteristics:
   Hull has a flush deck,
     a straight bulbous bow and small transom stern
   Block coefficient (normal/deep): 0.516 / 0.528
   Length to Beam Ratio: 9.74 : 1
   'Natural speed' for length: 26.28 kts
   Power going to wave formation at top speed: 58 %
   Trim (Max stability = 0, Max steadiness = 100): 42
   Bow angle (Positive = bow angles forward): 16.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  27.00 ft / 8.23 m,  24.50 ft / 7.47 m
      - Forward deck:   40.00 %,  24.50 ft / 7.47 m,  22.00 ft / 6.71 m
      - Aft deck:   25.00 %,  22.00 ft / 6.71 m,  20.53 ft / 6.26 m
      - Quarter deck:   15.00 %,  20.53 ft / 6.26 m,  20.53 ft / 6.26 m
      - Average freeboard:      22.80 ft / 6.95 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 91.8 %
      - Above water (accommodation/working, high = better): 195.1 %
   Waterplane Area: 25,596 Square feet or 2,378 Square metres
   Displacement factor (Displacement / loading): 119 %
   Structure weight / hull surface area: 98 lbs/sq ft or 478 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.84
      - Longitudinal: 1.62
      - Overall: 0.90
   Caution: Hull subject to strain in open-sea
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Good seaboat, rides out heavy weather easily

misc
45t FC
25t LR radio

5t paravanes
80t 4x floatplanes
10t - 2x Catapults
20t - hanger in stern