Parthian vessels 1916 onwards

Kaiser Kirk · March 10, 2022, 04:38:26 PM

was tinkering around and came up with this for ~1924/25 as a successor to the Zemaka class ACRs.
Doubt I will build it, but I wanted to see what the combination would 'Cost for the new guns I'm building, with a 29-31knot speed and 240mm belt.

Ultimately, it 'costs' 4000 tons (aka 3 destroyers) more than a Zemaka, is slightly slower and the only thing it can 'beat' that a Zemaka can not
is likely an older 'battlecruiser'.

On the other hand, by time I get to 1924-25 there may be other things out there this could be useful for. We shall see.

Quote
RPN Rustahem Suren, Parthian Heavy Armored Cruiser laid down 1923 (Engine 1925)

Displacement:
   22,599 t light; 24,238 t standard; 25,342 t normal; 26,225 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (622.54 ft / 615.16 ft) x 82.02 ft (Bulges 85.30 ft) x (30.18 / 31.05 ft)
   (189.75 m / 187.50 m) x 25.00 m (Bulges 26.00 m) x (9.20 / 9.47 m)

Armament:
8 - 12.99" / 330 mm 43.9 cal guns - 1,322.77lbs / 600.00kg shells, 154 per gun
     Breech loading guns in turret on barbette mounts, 1923 Model
     2 x 4-gun mounts on centreline ends, evenly spread
16 - 5.12" / 130 mm 50.0 cal guns - 70.55lbs / 32.00kg shells, 250 per gun
     Quick firing guns in deck and hoist mounts, 1923 Model
     6 x 2-gun mounts on side ends, majority forward
      2 raised mounts - superfiring
     2 x 2-gun mounts on centreline ends, evenly spread
      2 raised mounts
8 - 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, 1923 Model
     4 x 2-gun mounts on side ends, evenly spread
      4 raised mounts
4 - 2.24" / 57.0 mm 60.0 cal guns - 6.61lbs / 3.00kg shells, 750 per gun
     Anti-air guns in deck and hoist mounts, 1923 Model
     2 x Twin mounts on centreline ends, evenly spread
      2 double raised mounts
16 - 0.59" / 15.0 mm 70.0 cal guns - 0.11lbs / 0.05kg shells, 5,000 per gun
     Machine guns in deck mounts, 1923 Model
     8 x Twin mounts on sides, evenly spread
      8 double raised mounts
Weight of broadside 11,933 lbs / 5,413 kg

Armour:
- Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   9.45" / 240 mm   449.08 ft / 136.88 m   13.25 ft / 4.04 m
   Ends:   1.57" / 40 mm   166.08 ft / 50.62 m   13.25 ft / 4.04 m
     Main Belt covers 112 % of normal length
     Main Belt inclined -15.00 degrees (positive = in)

- Torpedo Bulkhead - Additional damage containing bulkheads:
      1.50" / 38 mm   449.08 ft / 136.88 m   28.12 ft / 8.57 m
   Beam between torpedo bulkheads 64.30 ft / 19.60 m

- Hull Bulges:
      0.35" / 9 mm   407.64 ft / 124.25 m   23.62 ft / 7.20 m

- Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   12.2" / 310 mm   7.09" / 180 mm      9.45" / 240 mm
   2nd:   2.95" / 75 mm   1.77" / 45 mm      1.77" / 45 mm
   3rd:   1.38" / 35 mm   0.98" / 25 mm      0.98" / 25 mm
   4th:   0.51" / 13 mm     -           -
   5th:   0.31" / 8 mm     -           -

- Armoured deck - single deck:
   For and Aft decks: 2.76" / 70 mm
   Forecastle: 1.38" / 35 mm Quarter deck: 2.76" / 70 mm

- Conning towers: Forward 9.45" / 240 mm, Aft 2.95" / 75 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 3 shafts, 122,369 shp / 91,288 Kw = 30.00 kts
   Range 5,165nm at 14.00 kts
   Bunker at max displacement = 1,987 tons

Complement:
   1,003 - 1,305

Cost:
   £6.628 million / $26.511 million

Distribution of weights at normal displacement:
   Armament: 2,205 tons, 8.7 %
     - Guns: 2,205 tons, 8.7 %
   Armour: 6,725 tons, 26.5 %
     - Belts: 2,461 tons, 9.7 %
     - Torpedo bulkhead: 699 tons, 2.8 %
     - Bulges: 126 tons, 0.5 %
     - Armament: 1,461 tons, 5.8 %
     - Armour Deck: 1,747 tons, 6.9 %
     - Conning Towers: 231 tons, 0.9 %
   Machinery: 3,973 tons, 15.7 %
   Hull, fittings & equipment: 9,010 tons, 35.6 %
   Fuel, ammunition & stores: 2,743 tons, 10.8 %
   Miscellaneous weights: 687 tons, 2.7 %
     - Hull below water: 228 tons
     - Bulge void weights: 110 tons
     - Hull above water: 48 tons
     - On freeboard deck: 30 tons
     - Above deck: 271 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     29,603 lbs / 13,428 Kg = 27.0 x 13.0 " / 330 mm shells or 4.1 torpedoes
   Stability (Unstable if below 1.00): 1.13
   Metacentric height 4.7 ft / 1.4 m
   Roll period: 16.5 seconds
   Steadiness   - As gun platform (Average = 50 %): 51 %
         - Recoil effect (Restricted arc if above 1.00): 0.88
   Seaboat quality (Average = 1.00): 1.02

Hull form characteristics:
   Hull has a flush deck,
     a ram bow and a cruiser stern
   Block coefficient (normal/deep): 0.560 / 0.563
   Length to Beam Ratio: 7.21 : 1
   'Natural speed' for length: 24.80 kts
   Power going to wave formation at top speed: 59 %
   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 %, 27.56 ft / 8.40 m, 25.26 ft / 7.70 m
     - Forward deck:   35.00 %, 25.26 ft / 7.70 m, 22.64 ft / 6.90 m
     - Aft deck:   38.00 %, 22.64 ft / 6.90 m, 22.64 ft / 6.90 m
     - Quarter deck:   7.00 %, 22.64 ft / 6.90 m, 24.28 ft / 7.40 m
     - Average freeboard:      23.86 ft / 7.27 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 112.1 %
      - Above water (accommodation/working, high = better): 157.1 %
   Waterplane Area: 35,544 Square feet or 3,302 Square metres
   Displacement factor (Displacement / loading): 105 %
   Structure weight / hull surface area: 180 lbs/sq ft or 878 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.92
      - Longitudinal: 2.08
      - Overall: 1.00
   Cramped machinery, storage, compartmentation space
   Excellent accommodation and workspace room

The goal of this vessel is to explore if the new 330L43.9 can be used to
produce a superior armored cruiser to the Zemaka class without exorbidant displacement.

3 (5) 7
(b) (d)
A (1) [a] [f] (2) B
(c) (e)
4 (6) 8
A-B Main
1-6 2nd
a-f AA
( ) 1 up
[ ] 2 up

The ship can fire 10x 130 forward, 10x 130 on either beam and 10x 130 aft.
The AA suite is increased to 8x 90AA, with 4 in each direction, and twin 57AA fore & Aft covering 270deg arcs.

The resulting vessel is nearly the size of an early Gilgamesh but
50% faster.

It is expected to be able to dominate all older armored cruisers at any range.
There are big fast ships that have comparable or better armanent and are 50% to 100%
larger, but precious few are expected to be able to catch it.

Belt
3.9 cos (15) = 4.03+

The TDS is only twinned 19mm plates, but spaced a full 3m inboard, with a 0.5m bulge on each side for standoff distance. A liquid/void loading with simple hull dividing is used.

Misc Wt :
110t - Reserve

221t - FC
25t - Searchlight Tower
25t - LR Radio

25t - Hulesmeyer
5t - Paravanes

23t - CO2 Air Compressor AC
25t - Enhanced Fire Suppression

25t - Enhanced Pumps
15t - Enhanced hydrophones.
188t - Torpedo nets

Decks

6.9 - Forecastle
4.4 - Weather
1.9 - Main Armor Deck, top TDS, Top Main Belt
-0.6 - Deck
- 2.0 Bottom Main Belt.
-3.1- Deck
-6.9 - Engineering
-8.1 - Double Bottom

Jefgte · March 10, 2022, 05:15:41 PM

Quote...Ultimately, it 'costs' 4000 tons (aka 3 destroyers)...

Byzantium reduces the cost of these cruisers and adopts the Panzerschiff format => 2T3.
AC9 class (Isparta) 13750t is reduced to 11485t and allows the construction of 8 additional torpedo boats for colonies.

Kaiser Kirk · March 10, 2022, 07:14:21 PM

Different design goals.

The designs I have that are similar to the Isparta are what I call Light Armored Cruisers, usually 230mm armed,
or various Capharact designs with either 255 or 300.

The AC9 was just laid down, so the Parthians do not have any real data on it.
The Zemaka class was designed without reference to it.

Looking at the design I note : Beam between torpedo bulkheads 71,59 ft / 21,82 m
Which since your beam is 21,82m, means your TDS is just a 40mm plate behind the hull.
You may want to revise the vessel some.
At least 2-2.5m on each side, so an internal beam of 16.82-17.82.

That may mean you need a longer citadel
and have to adjust your forecastle and stern to get the longer belt/TDS/Armor deck

Sorry to bring this up late but I have been busy enough I don't browse designs alot recently.
actually, what tends to draw my eye is if some other nation's player comments on a thread.
But even then, I haven't had the time.

Kaiser Kirk · March 11, 2022, 07:58:42 PM

The 1905 Rustam class AC would have completed in 1907.
So it is only 14 years old. The Royal navy estimated capital ship lifespans at 26 years, so it is a little past half.

At 23.5 knots it is slightly faster than the Byzantine battleline, but slower than anything else.
The 20knot predreads like Rohk and Smurgh are expected to be slow and tough, but ACs are meant to go mix it up

So this class is planned for refurbishment as well.
As such, this class will also be the testbed for the new 1918 fire control, and the first operational ship launched spotter planes.
Then fleet wide FC upgrades can be rolled out in 1922.

The 1913 230L44 gun, was designed so it could replace the twin mount 245L40s in Bucephalus and Sparabara classes,
and it was just light enough to fit as a single where the Rustam's twin 180L40 turrets were.
Then the refits were delayed

So Option A ) Change to 2T2 255L49, the new gun, with 4T2 180L43 for spotting.
Or Option B ) Change to a uniform 8x 230L44 battery.

While replacing the original 255L50 2T2 is a loss of power, that would have to mix with the 180s for spotting - inflicting the 'multiship firing' penalty on solo fights.

With the 230L44s, they expect the all-big-gun arrangement of more modern and faster firing to be able to maintain long range spotting.
The guns loose ~10-15% penetration compared to the original battery, but they can still destroy a cruiser-armored foe at decent ranges.

The 28knots means the ship can operate with the current Parthian cruisers and there are only a handful of ships out there both significantly faster (2-3knts) to force battle and more powerful.

1921 Refurbishment

Old Engines : 2791
Old Bunker : 1777
Old main mag : 143

Main : Gun + Mounts : 442
Sec : Gun + Mounts : 324

Armanent :
New 230 2-G : 399
New 230 singles : 319
Turret Armor : 104+182 : 286
New Mag : 300t

Replace 90mm with 130mm casements
New 130C : 164
New Armor: 121
Mag :75

Replace 60mm with 90mm AA, install Twin 57AA
New AA :37.4
New Armor :22.44
Mag :27.8

Total Guns & Mounts : 919t
Total Armor: 429
Total Mag : 403

New Oil-fired Engines : 2486
New Bunkers : 1732

Laminate +15 mm to main armor deck :267
Effective thickness 37 / (25+52) / 52

New Misc. Weight :
60t void weight.

92t - Fire Control
25t - Searchlight tower (NF)
25t - Hulesmeyer

5t - Gunpowder catapult
20t - Reconnaisance floatplane
25t War Tuba
5t Paravanes

13t - CO2 compressor AC
25t - Enhanced Fire Ext.

148t - Torpedo Nets
25t - enhanced pumps
15t - enhanced hydrophones

148t - Torpedo Nets

Costs :
A) 20% of 12296/1000 : 2.4592$
B) Machinery : 2486
Guns : 919
Subttoal : 3405
Cost : $6.81, 3.405B
C) Armor : 429 +267 = 696
Func (all but void) = 423
Subtotal : $1.119, 1.119BP
D) Hull : 4,203/5000 - Note I actually made no change tothe Hull other than non-functional bow angle, I have decided as a storyline aspect for 'repairs' of wear and tear. Though I think that is the 20% up front cost.
....and then decided if I'm doing that I can raise the bow ever so slightly to +0.5m
which just pushes it to 1.01 seakeeping from 1.00.
= $0.8406
E) Fuel, Mag, NF misc : 1732 + 403 + 60t = 2195/2000 = $1.0975

Subtotal :
2.4592
6.810 3.405
1.119 1.119
0.8406
1.0975
---------------------
$12.3263 4.524B
--------------------
$12.33 4.52B

5.55 4th Deck, top of upper belt, 25mm armor deck .
3.05 3rd Deck
1.05 Top of Main Belt, bottom uppe belt
0.55 2nd Deck, Crown of 40mm Protective Deck
-1.95 1st deck, bottom of Protective deck,bottom of Main belt.
-6.95 Engineering Deck (2 decks height)

Quote
Rustam, Parthian Armored cruiser laid down 1905 (Engine 1921)

Displacement:
   12,280 t light; 12,961 t standard; 13,924 t normal; 14,693 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (492.13 ft / 485.56 ft) x 68.90 ft x (24.61 / 25.72 ft)
   (150.00 m / 148.00 m) x 21.00 m x (7.50 / 7.84 m)

Armament:
4 - 9.06" / 230 mm 44.0 cal guns - 392.42lbs / 178.00kg shells, 164 per gun
     Breech loading guns in turret on barbette mounts, 1904 Model
     2 x 2-gun mounts on centreline ends, evenly spread
4 - 9.06" / 230 mm 44.0 cal guns - 392.42lbs / 178.00kg shells, 180 per gun
     Breech loading guns in turret on barbette mounts, 1913 Model
     4 x Twin mounts on side ends, evenly spread
12 - 5.12" / 130 mm 50.0 cal guns - 70.55lbs / 32.00kg shells, 160 per gun
     Quick firing guns in casemate mounts, 1913 Model
     12 x Single mounts on sides, evenly spread
      12 hull mounts in casemates- Limited use in heavy seas
4 - 3.54" / 90.0 mm 50.0 cal guns - 24.25lbs / 11.00kg shells, 350 per gun
     Anti-air guns in deck and hoist mounts, 1911 Model
     4 x Single mounts on side ends, evenly spread
      4 raised mounts
4 - 2.24" / 57.0 mm 60.0 cal guns - 6.61lbs / 3.00kg shells, 600 per gun
     Anti-air guns in deck and hoist mounts, 1917 Model
     2 x Twin mounts on centreline ends, evenly spread
      2 raised mounts
Weight of broadside 4,109 lbs / 1,864 kg

Armour:
- Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   7.09" / 180 mm   315.62 ft / 96.20 m   9.84 ft / 3.00 m
   Ends:   3.54" / 90 mm   169.91 ft / 51.79 m   9.84 ft / 3.00 m
   Upper:   3.54" / 90 mm   282.81 ft / 86.20 m   14.76 ft / 4.50 m
     Main Belt covers 100 % 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:   7.48" / 190 mm   3.54" / 90 mm      7.09" / 180 mm
   2nd:   7.48" / 190 mm   3.54" / 90 mm      5.31" / 135 mm
   3rd:   3.94" / 100 mm   1.77" / 45 mm      1.77" / 45 mm
   4th:   0.98" / 25 mm   0.98" / 25 mm      0.98" / 25 mm
   5th:   0.31" / 8 mm     -         0.31" / 8 mm

- Protected deck - multiple decks:
   For and Aft decks: 3.15" / 80 mm
   Forecastle: 1.57" / 40 mm Quarter deck: 2.17" / 55 mm

- Conning towers: Forward 7.09" / 180 mm, Aft 3.54" / 90 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 72,194 shp / 53,856 Kw = 28.00 kts
   Range 6,400nm at 14.00 kts
   Bunker at max displacement = 1,732 tons

Complement:
   640 - 833

Cost:
   £1.105 million / $4.419 million

Distribution of weights at normal displacement:
   Armament: 920 tons, 6.6 %
     - Guns: 920 tons, 6.6 %
   Armour: 4,188 tons, 30.1 %
     - Belts: 1,819 tons, 13.1 %
     - Armament: 916 tons, 6.6 %
     - Armour Deck: 1,320 tons, 9.5 %
     - Conning Towers: 133 tons, 1.0 %
   Machinery: 2,486 tons, 17.9 %
   Hull, fittings & equipment: 4,203 tons, 30.2 %
   Fuel, ammunition & stores: 1,644 tons, 11.8 %
   Miscellaneous weights: 483 tons, 3.5 %
     - Hull below water: 188 tons
     - Hull void weights: 60 tons
     - Hull above water: 38 tons
     - On freeboard deck: 55 tons
     - Above deck: 142 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     18,732 lbs / 8,497 Kg = 50.5 x 9.1 " / 230 mm shells or 2.2 torpedoes
   Stability (Unstable if below 1.00): 1.14
   Metacentric height 3.7 ft / 1.1 m
   Roll period: 15.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 50 %
         - Recoil effect (Restricted arc if above 1.00): 0.58
   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): 0.592 / 0.598
   Length to Beam Ratio: 7.05 : 1
   'Natural speed' for length: 22.04 kts
   Power going to wave formation at top speed: 62 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 12.00 degrees
   Stern overhang: -6.56 ft / -2.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
     - Forecastle:   20.00 %, 28.05 ft / 8.55 m, 26.41 ft / 8.05 m
     - Forward deck:   30.00 %, 26.41 ft / 8.05 m, 26.41 ft / 8.05 m
     - Aft deck:   35.00 %, 18.21 ft / 5.55 m, 18.21 ft / 5.55 m
     - Quarter deck:   15.00 %, 18.21 ft / 5.55 m, 19.85 ft / 6.05 m
     - Average freeboard:      22.56 ft / 6.88 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 82.9 %
      - Above water (accommodation/working, high = better): 159.0 %
   Waterplane Area: 24,285 Square feet or 2,256 Square metres
   Displacement factor (Displacement / loading): 109 %
   Structure weight / hull surface area: 123 lbs/sq ft or 600 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.91
      - Longitudinal: 2.32
      - Overall: 1.00
   Excellent machinery, storage, compartmentation space
   Excellent accommodation and workspace room

TacCovert4 · March 11, 2022, 08:39:38 PM

I think the 230 variant is correct. Going with the 255/180 split, you're basically the worst of both worlds. The 230s at least make it competitive with the next generation that is coming out.

Kaiser Kirk · March 11, 2022, 11:00:42 PM

Yeah, I am leaning towards that as well.

Hmm, I forgot the 25t for a LR radio.
Guess I can take it out of Misc wt or...oh I will ditch the war tuba.
I think I've had them in service enough to realize they are not
terribly useful at sea under way.

Kaiser Kirk · March 13, 2022, 06:00:29 PM

A couple turns ago there was a brief discussion about how many cruisers, how fast and how heavily gunned.
I am slowly assembling my Warships tab for my turn sheet, so I finally happen to have a place I can look to provide an answer

This also reflects all the recent upgrade work on older vessels.

In terms of vessels in service, Jan 1, 1922 :

27+kts : 8 cruisers, all 165
: 6x ACs : 2x 230, 4x255

28+kts : 9 cruisers, 5x 180, 1x 165, 3x 120
: 2x AC, 2x 230

29+kts : 14 cruisers, 2x 180, 12x 165

30+kts : 2 cruisers, 1x 180, 1x 165

Total 27kts +, 165mm + : 30 cruisers, 8 ACs

Kaiser Kirk · March 15, 2022, 12:36:15 AM

More tinkering with future potential vessels.

This one started as a USS Omaha- like vessel.
The originals were weakly built - their fuel tanks leaked in seaways- and lightly armored.
In N7 terms, they likely had insufficient comp hull.

In this case I was taking advantage of the 1920 Cruiser Tech 0.9 for 8000 and less.

This effort was upgunned to the Parthian 165mm,
but in recognition of Byzantine's 191mm ships, the 180L43 was fitted
and the vessel uparmored, costing speed and increasing tonnage.

The E and F iterations also featured the new 180L47 with the 90kg shell and power assist mounts.
I am really unsure how much weight to allocate for this...1 ton per feature (load/ram/train), 5% of rotating weight, 10% ?
Here I went with 10%

Two-gun mounts would actually be 'cheaper' weight wise, but the Parthians continue
to put a premium on limiting total mount weight and shell weight to keep the ability of the main
gun to track and engage fast close targets. A two-gun mount would then lead them to mount a secondary,
removing the advantage. The new 180L47 is in purpose-designed power assist mountings for that reason.

Quote
Omaha F 180mm, Parthian Cruiser laid down 1924

Displacement:
   7,999 t light; 8,436 t standard; 9,336 t normal; 10,055 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (589.65 ft / 583.99 ft) x 58.40 ft x (20.34 / 21.48 ft)
   (179.72 m / 178.00 m) x 17.80 m x (6.20 / 6.55 m)

Armament:
4 - 7.09" / 180 mm 47.0 cal guns - 198.42lbs / 90.00kg shells, 160 per gun
     Breech loading guns in deck and hoist mounts, 1924 Model
     4 x Single mounts on centreline ends, evenly spread
      2 raised mounts - superfiring
8 - 7.09" / 180 mm 47.0 cal guns - 198.42lbs / 90.00kg shells, 160 per gun
     Breech loading guns in casemate mounts, 1924 Model
     8 x Single mounts on side ends, evenly spread
      4 raised mounts
4 - 3.54" / 90.0 mm 50.0 cal guns - 24.25lbs / 11.00kg shells, 400 per gun
     Anti-air guns in deck and hoist mounts, 1924 Model
     2 x 2-gun mounts on sides amidships
      2 raised mounts
4 - 2.24" / 57.0 mm 60.0 cal guns - 6.61lbs / 3.00kg shells, 800 per gun
     Breech loading guns in deck mounts, 1924 Model
     2 x Twin mounts on centreline ends, evenly spread
      2 double raised mounts
16 - 0.59" / 15.0 mm 70.0 cal guns - 0.12lbs / 0.05kg shells, 5,000 per gun
     Machine guns in deck mounts, 1924 Model
     8 x Twin mounts on sides, evenly spread
      8 double raised mounts
Weight of broadside 2,506 lbs / 1,137 kg

Armour:
- Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   3.54" / 90 mm   420.47 ft / 128.16 m   10.89 ft / 3.32 m
   Ends:   Unarmoured
     Main Belt covers 111 % of normal length
     Main Belt inclined -15.00 degrees (positive = in)

- 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:   2.95" / 75 mm   1.77" / 45 mm      1.97" / 50 mm
   2nd:   1.97" / 50 mm   1.77" / 45 mm      1.77" / 45 mm
   3rd:   0.31" / 8 mm     -           -
   4th:   0.31" / 8 mm     -           -
   5th:   0.31" / 8 mm     -           -

- Armoured deck - single deck:
   For and Aft decks: 1.97" / 50 mm
   Forecastle: 1.38" / 35 mm Quarter deck: 1.38" / 35 mm

- Conning towers: Forward 3.54" / 90 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 3 shafts, 80,203 shp / 59,832 Kw = 32.00 kts
   Range 7,930nm at 14.00 kts
   Bunker at max displacement = 1,619 tons

Complement:
   474 - 617

Cost:
   £2.497 million / $9.988 million

Distribution of weights at normal displacement:
   Armament: 466 tons, 5.0 %
     - Guns: 466 tons, 5.0 %
   Armour: 1,614 tons, 17.3 %
     - Belts: 652 tons, 7.0 %
     - Armament: 147 tons, 1.6 %
     - Armour Deck: 781 tons, 8.4 %
     - Conning Tower: 34 tons, 0.4 %
   Machinery: 2,642 tons, 28.3 %
   Hull, fittings & equipment: 2,902 tons, 31.1 %
   Fuel, ammunition & stores: 1,337 tons, 14.3 %
   Miscellaneous weights: 375 tons, 4.0 %
     - Hull below water: 40 tons
     - Hull void weights: 100 tons
     - Hull above water: 33 tons
     - On freeboard deck: 105 tons
     - Above deck: 97 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     7,614 lbs / 3,454 Kg = 42.8 x 7.1 " / 180 mm shells or 1.3 torpedoes
   Stability (Unstable if below 1.00): 1.12
   Metacentric height 2.8 ft / 0.8 m
   Roll period: 14.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.56
   Seaboat quality (Average = 1.00): 1.06

Hull form characteristics:
   Hull has rise forward of midbreak,
     a ram bow and a cruiser stern
   Block coefficient (normal/deep): 0.471 / 0.480
   Length to Beam Ratio: 10.00 : 1
   'Natural speed' for length: 24.17 kts
   Power going to wave formation at top speed: 55 %
   Trim (Max stability = 0, Max steadiness = 100): 66
   Bow angle (Positive = bow angles forward): 12.00 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 %, 26.61 ft / 8.11 m, 24.15 ft / 7.36 m
     - Forward deck:   18.00 %, 24.15 ft / 7.36 m, 21.69 ft / 6.61 m
     - Aft deck:   54.00 %, 13.45 ft / 4.10 m, 13.45 ft / 4.10 m
     - Quarter deck:   8.00 %, 13.45 ft / 4.10 m, 14.44 ft / 4.40 m
     - Average freeboard:      17.53 ft / 5.34 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 109.8 %
      - Above water (accommodation/working, high = better): 140.7 %
   Waterplane Area: 22,143 Square feet or 2,057 Square metres
   Displacement factor (Displacement / loading): 106 %
   Structure weight / hull surface area: 90 lbs/sq ft or 441 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.87
      - Longitudinal: 1.14
      - Overall: 0.90
   Caution: Hull subject to strain in open-sea
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

Warning: Too many mounts in specific locations - 2nd Battery

Modeled on USS Omaha
with above-deck casements for end-on fire
and 180 vs. the US 6"

The belt is facehardened 90mm, outsloped 15 degrees
and capped by the armor deck.

3.2m/cos(15) = 3.312 = 3.32m

47t - Fire Control
25t - LR Radio
25t - Searchlight tower (NF)

18t - 2TT3 21" 3t
25+5 - Fighter Float + Gunpwdr CAT
57t - 10% rotating wt Power Assist for 180L47

8t - CO2 Compresser A/C
25t - Enhanced Fire Ext.

15t - Enhanced Hydrophones
25t - Extra Pumps.

Decks
+7.2
+4.7
+2.2 Top belt, Armored Deck
-0.3
-1.1 Bottom main belt
-2.8
-5.24 Engineering

-5.24 Double Bottom
-6.5 Keel

Kaiser Kirk · March 16, 2022, 12:25:58 AM

There are 3 real 'versions' of this concept.
The smallest is a 3m draft, coal/oil burning armed with 165mm and ~2400tons.
The jump to 27 knots, with oil firing, and a deeper draft for seakeeping ....is only 2600 tons.
This is the 3000 ton version, allowing 3 of the 180L43 mounts.

In all cases the Parthians see a need for a smaller cruiser that can be built in numbers and risked.

The 180mm were originally designed for their rotating weight and shell weight to be well within the range for unpowered use, and are provided with hoists so that shell supply can be kept up.

Both the 165mm 65kg and the 180mm 80kg can one-shot a destroyer, but the 180 is more effective against heavier targets.

Originally intended to replace the aged Dolphin gunboats in the far territories, the Porpoise is much like a USN Erie class.

The current version is meant as more a multi-role vessel.
The 4.4m draft is still suited for littoral work and can ascend major rivers.

However, the ship is given speed sufficient to work around the 20kt battleline if pressed into service.

As a Close Escort it would serve as an intermediate screen against MTBs and DDs, while also being equipped to detect and prosecute ASW attacks. It is thought that smaller cruisers like this could be used for 'Sprint and Drift', while the hull form allows good turns and the ability to prosecute the contact.

Against attacking destroyers, the single 180/ 165mm battery is expected to wreck havok. Against smaller cruisers, it is expected to at least give reasonable "punch", as speed will be insufficient to choose range, which is why the 180 is preferred.

Any offensive role would be at night for torpedo attacks, possibly as a follow up to an earlier attack. The Hulesmeyer device has not proved an effective early warning system, but is viewed as promising for night time formation steaming.

The way the gun layout is arranged, the B and Y guns are superimposed to clear A and the aft depth charge deck respectively.
The Torpedo tubes bracke the aft superstructure, which houses the fire control for them.

(3)
A(B) [1] TT (TDC) TT [4] (Y) [Depth Charges]
(4)

The protective deck is 35mm on the flat and 80mm on the slopes. Giving protection against QF weapons, but HE and SAP.

Porpoise, Parthian Frigate laid down 1923

Displacement:
   3,000 t light; 3,153 t standard; 3,770 t normal; 4,264 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (393.58 ft / 387.96 ft) x 51.67 ft x (14.44 / 15.78 ft)
   (119.96 m / 118.25 m) x 15.75 m x (4.40 / 4.81 m)

Armament:
3 - 7.09" / 180 mm 43.0 cal guns - 176.37lbs / 80.00kg shells, 200 per gun
     Breech loading guns in deck and hoist mounts, 1923 Model
     1 x Single mount on centreline forward
     2 x Single mounts on centreline ends, evenly spread
      2 raised mounts
8 - 2.24" / 57.0 mm 60.0 cal guns - 6.61lbs / 3.00kg shells, 600 per gun
     Anti-air guns in deck and hoist mounts, 1923 Model
     2 x Twin mounts on sides amidships
      2 raised mounts
     2 x Twin mounts on centreline ends, evenly spread
      2 double raised mounts
8 - 0.59" / 15.0 mm 60.0 cal guns - 0.11lbs / 0.05kg shells, 3,000 per gun
     Machine guns in deck mounts, 1923 Model
     4 x Twin mounts on side ends, evenly spread
      4 double raised mounts
Weight of broadside 583 lbs / 264 kg

Armour:
- Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   1.77" / 45 mm   252.17 ft / 76.86 m   12.01 ft / 3.66 m
   Ends:   Unarmoured
     Main Belt covers 100 % 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:   2.95" / 75 mm   1.38" / 35 mm      1.97" / 50 mm
   2nd:   0.24" / 6 mm     -           -

- Protected deck - single deck:
   For and Aft decks: 1.38" / 35 mm
   Forecastle: 0.00" / 0 mm Quarter deck: 1.38" / 35 mm

- Conning towers: Forward 1.97" / 50 mm, Aft 1.38" / 35 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 28,300 shp / 21,112 Kw = 27.00 kts
   Range 6,840nm at 16.00 kts
   Bunker at max displacement = 1,111 tons

Complement:
   239 - 312

Cost:
   £0.848 million / $3.393 million

Distribution of weights at normal displacement:
   Armament: 148 tons, 3.9 %
     - Guns: 148 tons, 3.9 %
   Armour: 587 tons, 15.6 %
     - Belts: 226 tons, 6.0 %
     - Armament: 43 tons, 1.1 %
     - Armour Deck: 300 tons, 8.0 %
     - Conning Towers: 17 tons, 0.5 %
   Machinery: 946 tons, 25.1 %
   Hull, fittings & equipment: 1,076 tons, 28.5 %
   Fuel, ammunition & stores: 770 tons, 20.4 %
   Miscellaneous weights: 243 tons, 6.4 %
     - Hull below water: 63 tons
     - Hull void weights: 45 tons
     - Hull above water: 15 tons
     - On freeboard deck: 55 tons
     - Above deck: 65 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     3,781 lbs / 1,715 Kg = 21.2 x 7.1 " / 180 mm shells or 1.1 torpedoes
   Stability (Unstable if below 1.00): 1.22
   Metacentric height 2.7 ft / 0.8 m
   Roll period: 13.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.31
   Seaboat quality (Average = 1.00): 1.01

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.456 / 0.472
   Length to Beam Ratio: 7.51 : 1
   'Natural speed' for length: 19.70 kts
   Power going to wave formation at top speed: 60 %
   Trim (Max stability = 0, Max steadiness = 100): 69
   Bow angle (Positive = bow angles forward): 17.00 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, 15.91 ft / 4.85 m
     - Forward deck:   40.00 %, 15.91 ft / 4.85 m, 13.45 ft / 4.10 m
     - Aft deck:   25.00 %, 13.45 ft / 4.10 m, 13.45 ft / 4.10 m
     - Quarter deck:   15.00 %, 13.45 ft / 4.10 m, 13.45 ft / 4.10 m
     - Average freeboard:      14.63 ft / 4.46 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 98.2 %
      - Above water (accommodation/working, high = better): 145.5 %
   Waterplane Area: 12,851 Square feet or 1,194 Square metres
   Displacement factor (Displacement / loading): 116 %
   Structure weight / hull surface area: 61 lbs/sq ft or 296 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.70
      - Longitudinal: 1.34
      - Overall: 0.75
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

Misc Wt
45- Reserve

15t - FC (16t)
25t - Hulesmeyer
25t - Seachlight tower (Night fighting)

3t : CO2 Compressor A/C Air conditioning
36t : 4 x T3 21" Torpedoes
16t : Depth charges

15t : Extra Fire Fighting

15t : Bow Enhanced Hydrophone station
15t : Amidships Enhanced Hydrophone Station
15t : Extra pumps
18t : Set torpedo reloads
5t : Batteries for silent hunting

Decks :
4.1m : Weather Deck
1.6m : Battery Deck - crown of protective deck
-0.9m : bottom protective deck. 1st Deck
-3.4m : Engineering deck
-4.4 m : Keel

Jefgte · March 16, 2022, 01:53:29 AM

Byzantium has a similar approach with the Colonial Cruisers (AGB4600). 3000t to 6000t and able of escorting BBs. From 2T2x152 , 2T2x191 to 2T2x254 all 27kts.
However, older 27kts cruisers are going to be affected to colonies.
27kts is a correct speed for Colonial Cruisers.

The most modern cruisers will be assigned to the "Home Fleet".

Kaiser Kirk · March 16, 2022, 08:15:14 AM

I see your logic with that, and this smaller ship is emulating that.
I also see a greater need for numbers for presence, so small is good.
The 8000 ton cruiser is an interesting concept, but pricey, and not armored like I would prefer.

Also your bigger guns are why I went with my 'midsize' 180s.

Kaiser Kirk · March 17, 2022, 12:49:49 AM

More musing done while watching TV as my brain slowly turns off for the evening.

This is a smaller, slower, weaker armed version of the above,
but mainly meant for a different role - more coast guard cutter / gunboat

The old Dolphin and Recalde classes will eventually age out.
and something new needs to be the 'heavy' associate of
the CPC-1 gunboats and PS-1 patrol ships.

This does have 4 sets of torpedo tubes,
but I am thinking removing them for less on-deck hazards
and just going with a set of submarine-style bow tubes.

Then taking the deck space and weight for launches/marines.

Sabari, Parthian Patrol Corvette laid down 1923

Displacement:
   1,999 t light; 2,121 t standard; 2,208 t normal; 2,277 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (366.31 ft / 360.89 ft) x 42.65 ft x (9.84 / 10.08 ft)
   (111.65 m / 110.00 m) x 13.00 m x (3.00 / 3.07 m)

Armament:
6 - 5.12" / 130 mm 50.0 cal guns - 70.55lbs / 32.00kg shells, 250 per gun
     Quick firing guns in deck and hoist mounts, 1923 Model
     1 x 2-gun mount on centreline forward
     2 x 2-gun mounts on centreline ends, evenly spread
      2 raised mounts
8 - 2.24" / 57.0 mm 60.0 cal guns - 6.61lbs / 3.00kg shells, 600 per gun
     Anti-air guns in deck and hoist mounts, 1923 Model
     2 x Twin mounts on sides amidships
      2 raised mounts
     2 x Twin mounts on centreline ends, evenly spread
      2 double raised mounts
8 - 0.59" / 15.0 mm 60.0 cal guns - 0.11lbs / 0.05kg shells, 3,000 per gun
     Machine guns in deck mounts, 1923 Model
     4 x Twin mounts on side ends, evenly spread
      4 double raised mounts
Weight of broadside 477 lbs / 216 kg

Armour:
- Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   2.36" / 60 mm   234.58 ft / 71.50 m   9.51 ft / 2.90 m
   Ends:   Unarmoured
     Main Belt covers 100 % 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:   2.36" / 60 mm   0.98" / 25 mm      1.57" / 40 mm
   2nd:   0.24" / 6 mm     -           -

- Armoured deck - single deck:
   For and Aft decks: 1.38" / 35 mm

- Conning towers: Forward 2.36" / 60 mm, Aft 0.98" / 25 mm

Machinery:
   Coal and oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 11,184 shp / 8,343 Kw = 23.00 kts
   Range 3,200nm at 10.00 kts
   Bunker at max displacement = 155 tons (23% coal)

Complement:
   160 - 209

Cost:
   £0.511 million / $2.045 million

Distribution of weights at normal displacement:
   Armament: 144 tons, 6.5 %
     - Guns: 144 tons, 6.5 %
   Armour: 479 tons, 21.7 %
     - Belts: 220 tons, 10.0 %
     - Armament: 30 tons, 1.4 %
     - Armour Deck: 217 tons, 9.8 %
     - Conning Towers: 12 tons, 0.6 %
   Machinery: 382 tons, 17.3 %
   Hull, fittings & equipment: 735 tons, 33.3 %
   Fuel, ammunition & stores: 208 tons, 9.4 %
   Miscellaneous weights: 259 tons, 11.7 %
     - Hull below water: 68 tons
     - Hull void weights: 50 tons
     - Hull above water: 15 tons
     - On freeboard deck: 61 tons
     - Above deck: 65 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     2,887 lbs / 1,310 Kg = 43.1 x 5.1 " / 130 mm shells or 1.0 torpedoes
   Stability (Unstable if below 1.00): 1.12
   Metacentric height 1.7 ft / 0.5 m
   Roll period: 13.6 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.58
   Seaboat quality (Average = 1.00): 1.25

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.510 / 0.514
   Length to Beam Ratio: 8.46 : 1
   'Natural speed' for length: 19.00 kts
   Power going to wave formation at top speed: 52 %
   Trim (Max stability = 0, Max steadiness = 100): 57
   Bow angle (Positive = bow angles forward): 17.00 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 %, 17.72 ft / 5.40 m, 15.42 ft / 4.70 m
     - Forward deck:   30.00 %, 15.42 ft / 4.70 m, 12.80 ft / 3.90 m
     - Aft deck:   35.00 %, 12.80 ft / 3.90 m, 12.80 ft / 3.90 m
     - Quarter deck:   15.00 %, 12.80 ft / 3.90 m, 12.80 ft / 3.90 m
     - Average freeboard:      13.90 ft / 4.24 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 84.3 %
      - Above water (accommodation/working, high = better): 165.1 %
   Waterplane Area: 10,350 Square feet or 962 Square metres
   Displacement factor (Displacement / loading): 110 %
   Structure weight / hull surface area: 53 lbs/sq ft or 261 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.71
      - Longitudinal: 1.21
      - Overall: 0.75
   Caution: Hull subject to strain in open-sea
   Adequate 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

Intended to replace the aged Dolphin gunboats
in the territories.

Named for Persian Dog Breeds, the Sarabi
is the Persian Mastiff, a guard dog.

The alternate name is Sage Mazandarari

A destroyer-esque hull falls in what the Parthians call a Corvette class.

A shallow 3m draft allows ascension of most rivers and littoral shallows. The ship is designed as multirole, capable of patrol, night fighting, and ASW roles.

Armor is sufficient to defeat destroyer rounds at 90deg at over ~7000m.

B and Y guns are superimposed to clear A and the aft depth charge deck respectively.
The Torpedo tubes bracke the aft superstructure, which houses the fire control for them.

(3)
A(B) [1] TT (TDC) TT [4] (Y) [Depth Charges]
(4)

The protective deck is 35mm on the flat and 80mm on the slopes. Giving protection against QF weapons, but HE and SAP.

Misc Wt
50- Reserve

15t - FC
25t - Hulesmeyer
25t - Seachlight tower (Night fighting)

2t : CO2 Compressor A/C Air conditioning
36t : 4 x T3 21" Torpedoes
16t : Depth charges
5t : Paravanes

15t : Extra Fire Fighting

15t : Bow Enhanced Hydrophone station
15t : Amidships Enhanced Hydrophone Station
15t : Extra pumps
18t : Set torpedo reloads
5t : Batteries for silent hunting

Decks :
3.9m : Weather Deck
1.4m : Armor Deck, Top main belt
-1.1m : 1st Deck
: -1.5 bottom main belt
-2.67: Engineering deck
-3.0 m : Keel

Jefgte · March 17, 2022, 01:41:05 AM

For me, 23kts is too low.
I will maintain the speed at 27kts for use in a Colonial Squadron.

--------------------

Older DD could be use in Colonies as GunBoat
If you remove TT from the 500t Spear class you could probably had 4x130(?).

The Rock Doctor · March 17, 2022, 06:54:16 AM

I'd suggest halving the torpedoes, but keeping them on deck for flexible aiming. There are going to be times where they don't want to be heading at the enemy when they launch.

The utility of the second hydrophone installation is what?

TacCovert4 · March 17, 2022, 07:28:51 AM

Also, underwater tubes tend to have issues launching at above 15kts.....above water tubes give you that option.

I'd suggest moving the torps to the aft deck....out of the way of likely incoming fire, and not around a bunch of important superstructure if they are hit and go off.