Parthian vessels 1916 onwards

[Jefgte]

Bakr, Parthian Empire Escort Cruiser laid down 1919

Navalism & the Escort Cruiser dilemme.
Escort Cruiser question is once again asked after N3, N4, N5...

...All of this suggests having a specialized 'escort' ship, which simply needs sufficient speed to manuever around fleet elements.
While the Parthian battleline is 20knots, the newest heavy ships are 26 knots, and the older ACs are 27knots. So a speed of roughly 27-28 knots is needed to ensure widest utlitily.

I must admit that the reasoning is unstoppable.
;)
27kts is sufficient to scout, escort, and engage enemy DDs and Scout Cruisers ... if BBs are 20-21kts.

Our Navies must be built according to our tactical and strategic needs not according to the ships that have existed even if these constitute a reference.

It is a formula that I have already used.

[Kaiser Kirk]

Footnote : USN 6"/53 on the Omahas were expected to penetrate 102mm at 6,300yards, and 51mm at 13,800yards. 

It wasn't just about the thin armor, but more the tons of ammo needed to feed all those guns. Golden BB has a lot higher chance to hit a critical spot. Note that at least for Japanese destroyer squadrons, they have one or two light cruisers present as leaders, specifically to provide cover fire against ships like these. Also the Fubukis are designed to take a bit more of a cruiser role and would have AP for the HV 5" guns.
[/quote]

I wouldn't know that about the Fubukis at this point, but I also wouldn't advocate AP for 5" - or planning on engaging a cruiser in a gun fight.

Against the 50mm version, you're correct, a 90deg shot could likely penetrate at 10km or less. So that may be a little light.
I ran expected penetration for the various Parthian guns so I have an idea of the 5" probably can do.
You'd probably only be able to penetrate a normal cruiser on a 90deg shot under about 6km, less at an angle.


Which is likely a night engagement, and so a closing engagement.
Presumably, you'd skirmish with DDs first, then meeting this vessel - a mixed line of Parthian cruisers. Only some of which would be this type.
At which point you have to unload (fire) the HE in your guns/lockers/hoists, bring up AP, and use that, ...if facing a cruiser which you ID as the right type.
If you pass the cruiser and start engaging a destroyer, you'll need to swap back.
Which would make for very limited utility.

As I recall, shots that penetrate have a chance at crits, shots that don't do very little. HE does 3x (?) shellwt and AP 1x, SAP 1.5x ? 
So, a single 130mm (or one of your 5") would drop one of your ~450floatation DDs to 'half health', while my DD above would be down to 2/3rds.
While one of my 165mm HE shells will pretty much kill any DD it hits.
While a 5" round- or lots of them - will sting and have a chance to crit.
The floatation on the Bakr is 5600, unless you get a mag explosion, it would take a very long time to kill with 5".


As for the magazines, I think that's an inherent risk, and good reason to fit the splinterproof armor deck.
It might be reason to convert the armor deck to a protective deck. At the ranges, no one will arc over the belt to strike the slopes.

[Kaiser Kirk]

Our Navies must be built according to our tactical and strategic needs not according to the ships that have existed even if these constitute a reference.

It is a formula that I have already used.

It's an excellent point.

This ship, with the high mast, the kite balloon, over-water acoustics, underwater acoustics, proximity alert (hulesmeyer) is a response to the heavy torpedo attack waves we've seen here.  So that I can find and respond quickly. It's a different challenge than they were looking at the real world. My newest battlewagons have heavy secondaries, TDS, and torpedo nets...but it's still best to find and engage the foe as far from the battleline as possible.

But at this point I'm expecting the battlewagons to engage at specific points - repelling a landing somewhere, controlling a strait, protecting landing at a foreign shore, or as a 'fall back' for raiders.
And so mass light craft attacks, or distant surface approaches by subs, would be part of the counter...especially if these actions are anywhere near the Red Sea and the Byzantine swarms. But I don't think the Byzantines will oblige to sailing into the Persian Gulf...

None of those battleline uses require a ton of speed. If my fleet gets alot faster because everyone else is, the ship looses alot of utility. Likewise, as better future tech comes available it will loose some utility, but most of our 10-15 year old ships are showing their age... .

[Jefgte]

...None of those battleline uses require a ton of speed. If my fleet gets alot faster because everyone else is, the ship looses alot of utility. Likewise, as better future tech comes available it will loose some utility, but most of our 10-15 year old ships are showing their age... .

These 27kts escort cruisers will always be used to scout and protect the Parthians 20kts BBs, Gilgamesh, Enki, Tiamat, Vazra.
The downgrading of these escort cruisers will not happen if they are modernized in 12 or 15 years.

[Kaiser Kirk]

So trying to include the critiques I toyed with the little Cruiser.

Still not sure if the 8x T2 130mm or 8x T1 165mm is a better choice, but the 130mm weigh 369tons while the 165mm weigh 300 tons.
Adding in Fore & Aft fire control, that's 443t vs. 360t - a 83ton difference.
Two 130mm rounds kill a DD, but do little to a Cruiser.
One 165mm round kills a DD, and hurts a Cruiser.
But 130mm fire faster...

Anyhow, the main difference is the end belts vanish and the forecastle is unarmored.
While the main belt drops to +1.5 above WL to -1m below WL, and thins to 90mm.
That's the minimum to be hardened and so can better defeat non-AP.

with a 4 m freeboard, and a ~2.5m deck, the 1.5m is the main armor deck, and so the belt covers from that to underwater 1m.
Should be satisfactory.

I could convert the armored deck to a protective deck, to give a 30mm slope behind the belt.
At this short ranges, the chance of a shell arcing over the belt to hit the slope is minimal....but does provide that Golden BB path>
I could close that path, but that would mean thinning the belt to 75mm pr less..which removes most of the reason to have a protective deck
So armored deck it is.

Speed ticks up to a full 28knots.

So...130mm or 165mm....I am leaning 165mm

Bakr, Parthian Empire Escort Cruiser laid down 1919

Displacement:
   4,495 t light; 4,806 t standard; 5,603 t normal; 6,240 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (460.96 ft / 456.04 ft) x 47.57 ft x (19.03 / 20.61 ft)
   (140.50 m / 139.00 m) x 14.50 m  x (5.80 / 6.28 m)

Armament:
      16 - 5.12" / 130 mm 50.0 cal guns - 77.16lbs / 35.00kg shells, 250 per gun
     Quick firing guns in deck and hoist mounts, 1919 Model
     4 x 2-gun mounts on centreline ends, evenly spread
      2 raised mounts - superfiring
     4 x 2-gun mounts on side ends, evenly spread
      4 - 3.54" / 90.0 mm 50.0 cal guns - 24.25lbs / 11.00kg shells, 500 per gun
     Anti-air guns in deck and hoist mounts, 1919 Model
     4 x Single mounts on side ends, evenly spread
      4 raised mounts
      Weight of broadside 1,332 lbs / 604 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   3.54" / 90 mm   310.11 ft / 94.52 m   8.20 ft / 2.50 m
   Ends:   Unarmoured
     Main Belt covers 105 % of normal length

   - Hull void:
      0.00" / 0 mm     0.00 ft / 0.00 m   0.00 ft / 0.00 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   3.94" / 100 mm   1.18" / 30 mm      3.54" / 90 mm
   2nd:   0.24" / 6 mm         -               -

   - Armoured deck - single deck:
   For and Aft decks: 1.18" / 30 mm
   Forecastle: 0.00" / 0 mm  Quarter deck: 1.18" / 30 mm

   - Conning towers: Forward 3.54" / 90 mm, Aft 1.97" / 50 mm

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 3 shafts, 38,089 shp / 28,415 Kw = 28.00 kts
   Range 6,600nm at 16.00 kts
   Bunker at max displacement = 1,434 tons

Complement:
   323 - 420

Cost:
   £1.041 million / $4.163 million

Distribution of weights at normal displacement:
   Armament: 369 tons, 6.6 %
      - Guns: 369 tons, 6.6 %
   Armour: 794 tons, 14.2 %
      - Belts: 367 tons, 6.5 %
      - Armament: 106 tons, 1.9 %
      - Armour Deck: 283 tons, 5.1 %
      - Conning Towers: 37 tons, 0.7 %
   Machinery: 1,353 tons, 24.1 %
   Hull, fittings & equipment: 1,593 tons, 28.4 %
   Fuel, ammunition & stores: 1,107 tons, 19.8 %
   Miscellaneous weights: 387 tons, 6.9 %
      - Hull below water: 60 tons
      - Hull void weights: 25 tons
      - Hull above water: 50 tons
      - On freeboard deck: 130 tons
      - Above deck: 122 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     4,940 lbs / 2,241 Kg = 73.7 x 5.1 " / 130 mm shells or 1.0 torpedoes
   Stability (Unstable if below 1.00): 1.10
   Metacentric height 2.0 ft / 0.6 m
   Roll period: 14.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 51 %
         - Recoil effect (Restricted arc if above 1.00): 0.65
   Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
   Hull has a flush deck,
     a ram bow and a cruiser stern
   Block coefficient (normal/deep): 0.475 / 0.489
   Length to Beam Ratio: 9.59 : 1
   'Natural speed' for length: 21.36 kts
   Power going to wave formation at top speed: 55 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 15.00 degrees
   Stern overhang: -3.28 ft / -1.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  18.37 ft / 5.60 m,  16.08 ft / 4.90 m
      - Forward deck:   35.00 %,  16.08 ft / 4.90 m,  13.45 ft / 4.10 m
      - Aft deck:   33.00 %,  13.45 ft / 4.10 m,  13.45 ft / 4.10 m
      - Quarter deck:   12.00 %,  13.45 ft / 4.10 m,  13.45 ft / 4.10 m
      - Average freeboard:      14.62 ft / 4.46 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 103.9 %
      - Above water (accommodation/working, high = better): 117.8 %
   Waterplane Area: 14,135 Square feet or 1,313 Square metres
   Displacement factor (Displacement / loading): 109 %
   Structure weight / hull surface area: 77 lbs/sq ft or 376 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.86
      - Longitudinal: 1.33
      - Overall: 0.90
   Caution: Hull subject to strain in open-sea
   Adequate machinery, storage, compartmentation space
   Adequate accommodation and workspace room

The Parthians are concerned that naval combat is looking
like rock>paper>scissors>rock.

The descriptions from the Sino-Japanese war of 'skirmish' lines seems to be an effective means of dealing with light fast raider forces. There seems to be further emerging threats such as aerial or undersea, both of which can likely be best handled if detected further out.

All of this suggests having a specialized 'escort' ship, which simply needs sufficient speed to manuever around fleet elements.
While the Parthian battleline is 20knots, the newest heavy ships are 26 knots, and the older ACs are 27knots. So a speed of roughly 27-28 knots is needed to ensure widest utlitily.

As they would conceptually be advanced to ~18000m towards any onrushing MTB/DD night attack, they need to be fitted with sufficient fire control to divide fire and rapidly destroy attackers on both sides of the vessel.

Seakeeping is not critical, as those light attackers would do poorly in heavier seastates.

Due to poor development of ASW techniques, they are fitted with depth charges and hydrophones, and equipped for battery use 'on station' while hunting. In reality they are far to big and expensive to be good choices in this role. The hydrophones will help pick up distant propellors though.

Misc Wt
25t - Wt Reserve

74t - Dual Fire Control
25t - LR radio
23t - 30m cage mast (battleship level sight lines)

25t - Hulesmeyer
25t - War Tubas
25t - Night Fighting
25t - Kite Balloon


22t - 2x T3 21" torpedoes on fantail
8t - depth charge rack on fan tail.

25t - Imp Fire suppression
5t - A/C
20t - additional accomodations

15t - Hydrophones
20t - Reserve space
25t - Imp Pumps


Decks :
4.1m: Weather deck
1.5m : Battery Deck, Top Main Belt, Crown protective deck deck
-1.0m : Main Deck,  Bottom main belt, lower edge protective deck
-4.5 : Engineering
-5.0 : Double bottom (liquid filled)

[Kaiser Kirk]

So the semi-final iteration of Bakr is above.
I've shown the Oceanic Destroyer. 1500 tons is worth it for the Pacific.

For the Fleet Destroyer, I wanted more in the 1000-1200 ton range.

I have a couple different versions.
I have a 4x 120mm with 6x 18"TTs
and a 3x 120mm with 6x 21" TTs.
I could do the 4x90mm instead of the 3x120mm.

I have the Misc weight to 21" on both, but at the cost of some of the ship's utility.
The real advantage of the 3x120mm is I have more spare wait for that utility aspect,
and I still have 2 guns forward, and a 'stinger' if pursued.

Anyhow, the 4x 120mm Fleet Destroyer.
I don't like the survivability being so low, but it's tight design.

Fleet Destroyer, Parthian Empire Fleet Destroyer laid down 1919

Displacement:
   996 t light; 1,049 t standard; 1,221 t normal; 1,359 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (325.48 ft / 321.52 ft) x 30.61 ft x (10.17 / 11.00 ft)
   (99.21 m / 98.00 m) x 9.33 m  x (3.10 / 3.35 m)

Armament:
      4 - 4.72" / 120 mm 43.0 cal guns - 55.12lbs / 25.00kg shells, 200 per gun
     Quick firing guns in deck mounts, 1919 Model
     4 x Single mounts on centreline ends, evenly spread
      2 raised mounts - superfiring
      1 - 3.54" / 90.0 mm 50.0 cal gun - 24.25lbs / 11.00kg shells, 300 per gun
     Anti-air gun in deck mount, 1919 Model
     1 x Single mount on centreline, aft deck forward
      1 raised mount
      Weight of broadside 245 lbs / 111 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.24" / 6 mm         -               -
   2nd:   0.24" / 6 mm         -               -

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 1 shaft, 23,173 shp / 17,287 Kw = 30.33 kts     Trial Speed: 31.28
   Range 4,800nm at 14.00 kts
   Bunker at max displacement = 310 tons

Complement:
   103 - 134

Cost:
   £0.287 million / $1.147 million

Distribution of weights at normal displacement:
   Armament: 39 tons, 3.2 %
      - Guns: 39 tons, 3.2 %
   Armour: 3 tons, 0.2 %
      - Armament: 3 tons, 0.2 %
   Machinery: 613 tons, 50.2 %
   Hull, fittings & equipment: 289 tons, 23.6 %
   Fuel, ammunition & stores: 225 tons, 18.5 %
   Miscellaneous weights: 52 tons, 4.2 %
      - Hull below water: 15 tons
      - Hull void weights: 6 tons
      - Hull above water: 7 tons
      - On freeboard deck: 20 tons
      - Above deck: 4 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     356 lbs / 161 Kg = 6.8 x 4.7 " / 120 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.52
   Metacentric height 1.7 ft / 0.5 m
   Roll period: 9.8 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.27
   Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
   Hull has a flush deck,
     a ram bow and a cruiser stern
   Block coefficient (normal/deep): 0.427 / 0.440
   Length to Beam Ratio: 10.50 : 1
   'Natural speed' for length: 17.93 kts
   Power going to wave formation at top speed: 64 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 15.00 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 %,  14.76 ft / 4.50 m,  13.12 ft / 4.00 m
      - Forward deck:   30.00 %,  13.12 ft / 4.00 m,  11.48 ft / 3.50 m
      - Aft deck:   35.00 %,  11.48 ft / 3.50 m,  11.48 ft / 3.50 m
      - Quarter deck:   15.00 %,  11.48 ft / 3.50 m,  11.48 ft / 3.50 m
      - Average freeboard:      12.19 ft / 3.72 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 173.9 %
      - Above water (accommodation/working, high = better): 128.4 %
   Waterplane Area: 5,853 Square feet or 544 Square metres
   Displacement factor (Displacement / loading): 68 %
   Structure weight / hull surface area: 28 lbs/sq ft or 138 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.28
      - Overall: 0.54
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room

Intended as a potential  Fleet destroyer.

Excellent seakeeping from a raised forecastle.
Range to reach a base and return at fleet speeds

Good light gun armanent
AA gun 
Heavy torpedo loadout
Enhanced Hydrophones for an ASW role

                                                   DC
A(B)          TT(AA)TT          (X) Y
                                                   DC

Range @ Speeds :
29.5kts(90%) :  605nm (20hrs)
25.5kts (50%) : 955nm (37hrs)
16kts : 3,400nm

With the fleet at 12-14knots,
14 or 16 knots allows reasonable range when working with the fleet from bases.

The ability to make a 36hr sweep of 900m allows
them to interdict substantial areas, acting as Coastal Torpedo boats for that purpose.



Misc wt :
6t     Reserve Wt.
3.9FC
12t   2TT3 18"
8t     DC
1t     CO2 A/C
1t     ASW Kite
5t     Paravanes
15t   Enhanced Hydrophone package

[Kaiser Kirk]

I was expecting some discussion on the Fleet Destroyer and the merits of 4x120 vs. 3x120 & more "stuff" vs. 4x 90.

Anyhow the Next is a 1913 'Never Built' for 'sharing'.

Anyhow, Tac's experiments with 180mm "frigates" put me in mind of the whole series of ships I was intending on building,
and then I needed to build land units and deployment points.

That was Waaaaay back for 1913.   I did a range of ships with 180mm in the 11-13,000t and 230mm in the 14-17,000t.
Anyhow, while most of those were 10x 180mm in single M&H, I did do this one with Twin M&H- wasn't paying attention to the rotating weight.


I'm calling these 'Light Armored Cruisers', as folks were starting to build 28,000 ton 'heavy armored cruisers'.
I still thought that if the idea is to kill off PCs/CLs, a smaller ship could do.

So, in hindsight, this would have been interesting to build in 1913.

Fusilade, Parthian Armored Cruiser laid down 1913 (Engine 1916)

Displacement:
   12,997 t light; 13,623 t standard; 15,030 t normal; 16,155 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (606.01 ft / 598.75 ft) x 72.18 ft x (22.97 / 24.30 ft)
   (184.71 m / 182.50 m) x 22.00 m  x (7.00 / 7.41 m)

Armament:
      12 - 7.09" / 180 mm 43.0 cal guns - 187.39lbs / 85.00kg shells, 190 per gun
     Breech loading guns in deck and hoist mounts, 1913 Model
     4 x 2-gun mounts on centreline ends, evenly spread
      2 raised mounts - superfiring
     2 x 2-gun mounts on centreline, forward deck aft
      1 raised mount - superfiring
      8 - 4.72" / 120 mm 45.0 cal guns - 55.12lbs / 25.00kg shells, 250 per gun
     Quick firing guns in casemate mounts, 1913 Model
     8 x Single mounts on centreline, forward deck aft
      1 raised mount
      4 - 3.54" / 90.0 mm 50.0 cal guns - 24.25lbs / 11.00kg shells, 500 per gun
     Anti-air guns in deck and hoist mounts, 1913 Model
     4 x Single mounts on sides, evenly spread
      4 double raised mounts
      Weight of broadside 2,787 lbs / 1,264 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   6.50" / 165 mm   496.98 ft / 151.48 m   14.76 ft / 4.50 m
   Ends:   0.98" / 25 mm   101.77 ft / 31.02 m   14.76 ft / 4.50 m
     Main Belt covers 128 % of normal length

   - Torpedo Bulkhead - Additional damage containing bulkheads:
      0.98" / 25 mm   496.98 ft / 151.48 m   20.77 ft / 6.33 m
   Beam between torpedo bulkheads 52.49 ft / 16.00 m

   - Hull void:
      0.00" / 0 mm     0.00 ft / 0.00 m   0.00 ft / 0.00 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   6.69" / 170 mm   2.56" / 65 mm      6.50" / 165 mm
   2nd:   0.98" / 25 mm   0.98" / 25 mm      0.98" / 25 mm
   3rd:   0.98" / 25 mm         -         0.59" / 15 mm

   - Armoured deck - single deck:
   For and Aft decks: 1.57" / 40 mm
   Forecastle: 0.79" / 20 mm  Quarter deck: 1.18" / 30 mm

   - Conning towers: Forward 5.71" / 145 mm, Aft 3.54" / 90 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 92,722 shp / 69,171 Kw = 30.50 kts
   Range 7,800nm at 14.00 kts
   Bunker at max displacement = 2,532 tons

Complement:
   678 - 882

Cost:
   £1.262 million / $5.047 million

Distribution of weights at normal displacement:
   Armament: 627 tons, 4.2 %
      - Guns: 627 tons, 4.2 %
   Armour: 3,553 tons, 23.6 %
      - Belts: 1,959 tons, 13.0 %
      - Torpedo bulkhead: 376 tons, 2.5 %
      - Armament: 247 tons, 1.6 %
      - Armour Deck: 849 tons, 5.7 %
      - Conning Towers: 121 tons, 0.8 %
   Machinery: 3,455 tons, 23.0 %
   Hull, fittings & equipment: 4,989 tons, 33.2 %
   Fuel, ammunition & stores: 2,033 tons, 13.5 %
   Miscellaneous weights: 373 tons, 2.5 %
      - Hull below water: 45 tons
      - Hull void weights: 90 tons
      - Hull above water: 25 tons
      - On freeboard deck: 60 tons
      - Above deck: 153 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     20,615 lbs / 9,351 Kg = 115.9 x 7.1 " / 180 mm shells or 2.9 torpedoes
   Stability (Unstable if below 1.00): 1.20
   Metacentric height 4.3 ft / 1.3 m
   Roll period: 14.6 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.45
   Seaboat quality  (Average = 1.00): 1.20

Hull form characteristics:
   Hull has rise forward of midbreak,
     a ram bow and a cruiser stern
   Block coefficient (normal/deep): 0.530 / 0.538
   Length to Beam Ratio: 8.30 : 1
   'Natural speed' for length: 24.47 kts
   Power going to wave formation at top speed: 57 %
   Trim (Max stability = 0, Max steadiness = 100): 58
   Bow angle (Positive = bow angles forward): 15.00 degrees
   Stern overhang: -6.56 ft / -2.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   10.00 %,  27.07 ft / 8.25 m,  26.25 ft / 8.00 m
      - Forward deck:   50.00 %,  26.25 ft / 8.00 m,  25.43 ft / 7.75 m
      - Aft deck:   33.00 %,  17.22 ft / 5.25 m,  17.22 ft / 5.25 m
      - Quarter deck:   7.00 %,  17.22 ft / 5.25 m,  18.04 ft / 5.50 m
      - Average freeboard:      22.49 ft / 6.86 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 123.8 %
      - Above water (accommodation/working, high = better): 186.4 %
   Waterplane Area: 29,602 Square feet or 2,750 Square metres
   Displacement factor (Displacement / loading): 116 %
   Structure weight / hull surface area: 117 lbs/sq ft or 570 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.95
      - Longitudinal: 1.57
      - Overall: 1.00
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

Designed to revert to the original missions of the armored cruiser, in a vessel roughly 50% larger than a protected cruiser, but the final design is closer to twice as large.
This is the follow on the prior Fusilade, ditching the wing mounts for a centerline turret arrangement, like a minature battleship.

A raised forecastle, an additional 1/2 knot of speed, the sacrifice of the upper belt, and an extra meter of beam to add a TDS mark vast changes in the basic design. The main armored deck has been raised to allow greater room for the engines, and consolidated to one 40mm deck, which should stop any armor cruiser round.

The new TDS is 3 m deep on each side and rises from the bilges at -6.33m to the bottom of the armored deck at 2.25m above the waterline. This allows the 25mm bulkhead to also serve as a splinter bulkhead.

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Miscellaneous Weight :
90t - Construction Reserve

126t - 2x Fire Control
25t -  LR Radio

60t - 'Windtower' evaporative cooling

25t- Extra pumps
20t - Underwater Torpedoes. Located aft of citadel, above quarterdeck armor. 2 TT2 18" each side. 6 reload TT below.

Decks :
7.75 - Forecastle deck.
5.25 - Weather Deck
2.75 - 50mm armored Battery Deck, top of main belt.
0.25 - Main deck
             - 1.75 Bottom Main Belt
-2.25 - 1st deck, 
-5.75 - Engineering Deck, 4m high
-6.33 - Double Hull.

[The Rock Doctor]

You may have mentioned it before, but why just 18" torps on the 1919 destroyer? 

[Desertfox]

I was expecting some discussion on the Fleet Destroyer and the merits of 4x120 vs. 3x120 & more "stuff" vs. 4x 90.

Well I stuffed 4x5" into 750tons so you know what I'd be leaning towards. In this day and age of 1500t DDs, the 90mm guns are mere popguns.

[Kaiser Kirk]

I didn't go into detail, but I did mention it.
I can spare the extra 6 tons to upgrade to 21" , but
then I either have no reserve, or give up some utility.

As for the merits of 21" vs. 18",
It's something I'm toying with.
I'm unsure of the proper choice of action.

Against most targets, which have no TDS, they both make a big hole that lets in huge amounts of water.
That hole is actually about the same size for both.

Against a target with a TDS, which should be the minority, it seems likely that most designs will be intended
to thwart the 1908 or 1913 tech 21" version, and so presumably a 1 or 2 torpedo hit kill is unlikely with either.

So the main effect is rupturing the side shell and causing flooding ... which both do...and slow down the enemy vessel.
OR...if it's already battered, then a whole bunch of torpedoes can be used, in which case the TDS can be overwhelmed.

I have a couple different versions.
I have a 4x 120mm with 6x 18"TTs
and a 3x 120mm with 6x 21" TTs.
I could do the 4x90mm instead of the 3x120mm.

I have the Misc weight to 21" on both, but at the cost of some of the ship's utility.
The real advantage of the 3x120mm is I have more spare wait for that utility aspect,
and I still have 2 guns forward, and a 'stinger' if pursued.

[Kaiser Kirk]

In this day and age of 1500t DDs, the 90mm guns are mere popguns.

I would prefer a 100mm option, for a better ROF/shell wt trade off, but I don't have that gun.
The 1,500tonners just can't take much damage, and would degrade quickly from it.
So I am trying to have capable and smaller DDs which I can afford in more reasonable numbers.

[TacCovert4]

In this day and age of 1500t DDs, the 90mm guns are mere popguns.

I would prefer a 100mm option, for a better ROF/shell wt trade off, but I don't have that gun.
The 1,500tonners just can't take much damage, and would degrade quickly from it.
So I am trying to have capable and smaller DDs which I can afford in more reasonable numbers.

Nothing wrong with small and reasonable.  That's why I have a swarm of GTBs in service.  I needed something 'dd-ish', I needed a lot of them, and I couldn't afford to wait due to losses in the Caicos War.  So I build 500 tonners en masse to create the DD-like torpedo threat and as close to a DD gun threat as possible for literal peanuts.

I mean, I don't like 3 gun DDs, 4 guns is sort of a minimum in my opinion, but 3 is somewhat doable for a DD because of the relatively shorter ranges involved in DD combat.

I understand your 'generalist destroyer' needs, with those in mind the 3x120 is adequate I think.  I'd shy away from 90mm as it's not heavy enough to even threaten a cruiser at all, which is problematic for something this size. 

No, it's not going to match up with things like my D class fleet destroyers.  Or the upcoming F class.  But they're fleet destroyers with little or even no built in ASW. 

[Desertfox]

I would prefer a 100mm option, for a better ROF/shell wt trade off, but I don't have that gun.
The 1,500tonners just can't take much damage, and would degrade quickly from it.
So I am trying to have capable and smaller DDs which I can afford in more reasonable numbers.

I feel your pain, being in an even worse position not having anything between 75mm and 127mm, with sizes increasing its no longer as big of an issue, but did push Japanese destroyer design primarily towards surface warfare.

As for torpedo sizes the other advantage a 21" torpedo has is range. Japan didnt go with heavy 21" for warhead size but for range and speed capabilities. You can either hit them from further away, or you can hit them faster from the same range. Or you go with batteries and hit them silently from closer up.

[The Rock Doctor]

The 4x120mm design seems more optimized for a defensive role than an offensive one.

I suppose you could swap out two triple 18" carriages for a pair of double 21". 

You're having the same problem with destroyer guns that I have with cruiser guns:  Big gap in the inventory, lack of time/funding to fix it.

[TacCovert4]

Same problem that I have.  130mm, 180mm, 280mm in modern guns.  The 150s and 210s are really too old to be putting in new ships but I don't want to burn up my research on a lot of guns.