Parthian Ships 1928 +

Kaiser Kirk · September 15, 2024, 12:24:45 PM

I don't have room for this in my 1934HY2,

I am thinking a new version of the 'Royal Mail' fast mail/cargo/passengers is useful.
The Royal Marriages in Wilno and Azteca helped drive home just how far it is.

I have finished my Ahanita 'Mercy' ships, and will be building the 8th Hamberkastig Fleet Supply
vessel, and 6/8 planned Royn Oilers. That will bring me to 18 Fleet Supply Vessels, 8 oilers, and a bunch of fleet light tenders. Plus some supply barges.

I don't know how many I really need, but that seems a reasonable investment, and will support most of my fleet on extended overseas deployments.

After those runs are done...I'll have some spare BP to allocate.

At 14880 they cost the same.
The fuel faction is about the maximum (slightly over) you see with USN ships.

A handful of these would provide regular high speed service across Parthia.
More than a handfull would be an unreasonabley high storyline cost.

On Auxiliaries and conversions
The problem of avoiding making a vessel that would be a logical carrier conversion
but keeping the cruise speed high was one I had to think on. This also relates to Foxy's old distaste for limiting 'reasonable' speeds for auxiliaries and what a 'reasonable' call would be for that.

I think turbines can run at like 80% power reliably. I am unsure about Marine Diesel engines.
But the D-E drive and a 75% need should mean some can be offline for regular maintenance while the ship proceeds at full cruise. Picking a high % meant I only needed a little power over that,
so max speed is only 24 knots - below everyone's newer capital ships, and lower than early carrier launch speeds. So too slow to magically become a stealth fleet Carrier.

QuoteWabash, Parthia Cargo-Liner laid down 1935

Displacement:
14,880 t light; 15,324 t standard; 18,942 t normal; 21,836 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(622.17 ft / 610.24 ft) x 85.30 ft x (19.69 / 22.17 ft)
(189.64 m / 186.00 m) x 26.00 m x (6.00 / 6.76 m)

Armament:
8 - 4.72" / 120 mm 47.0 cal guns - 55.12lbs / 25.00kg shells, 200 per gun
Dual purpose guns in deck mounts, 1935 Model
8 x Single mounts on sides, evenly spread
16 - 1.18" / 30.0 mm 80.0 cal guns - 0.94lbs / 0.43kg shells, 2,000 per gun
Anti-air guns in deck mounts, 1929 Model
6 x 2-gun mounts on sides, evenly spread
6 raised mounts
2 x 2-gun mounts on centreline ends, evenly spread
2 double raised mounts
Weight of broadside 456 lbs / 207 kg

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Ends: Unarmoured

- Torpedo Bulkhead - Additional damage containing bulkheads:
0.98" / 25 mm 396.65 ft / 120.90 m 18.90 ft / 5.76 m
Beam between torpedo bulkheads 45.93 ft / 14.00 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: 0.79" / 20 mm - -
2nd: 0.79" / 20 mm - -

Machinery:
Diesel Internal combustion generators,
Electric motors, 4 shafts, 42,358 shp / 31,599 Kw = 24.00 kts
Range 7,632nm at 22.00 kts
Bunker at max displacement = 6,512 tons

Complement:
806 - 1,049

Cost:
£3.631 million / $14.524 million

Distribution of weights at normal displacement:
Armament: 95 tons, 0.5 %
- Guns: 95 tons, 0.5 %
Armour: 295 tons, 1.6 %
- Torpedo bulkhead: 273 tons, 1.4 %
- Armament: 22 tons, 0.1 %
Machinery: 1,203 tons, 6.4 %
Hull, fittings & equipment: 6,060 tons, 32.0 %
Fuel, ammunition & stores: 4,062 tons, 21.4 %
Miscellaneous weights: 7,227 tons, 38.2 %
- Hull below water: 2,692 tons
- Hull void weights: 50 tons
- Hull above water: 2,050 tons
- On freeboard deck: 2,240 tons
- Above deck: 195 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
60,820 lbs / 27,588 Kg = 1,153.6 x 4.7 " / 120 mm shells or 9.4 torpedoes
Stability (Unstable if below 1.00): 1.33
Metacentric height 6.6 ft / 2.0 m
Roll period: 14.0 seconds
Steadiness - As gun platform (Average = 50 %): 100 %
- Recoil effect (Restricted arc if above 1.00): 0.03
Seaboat quality (Average = 1.00): 2.00

Hull form characteristics:
Hull has a flush deck,
a ram bow and small transom stern
Block coefficient (normal/deep): 0.647 / 0.662
Length to Beam Ratio: 7.15 : 1
'Natural speed' for length: 26.68 kts
Power going to wave formation at top speed: 47 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 22.00 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 %, 29.53 ft / 9.00 m, 29.53 ft / 9.00 m
- Forward deck: 30.00 %, 29.53 ft / 9.00 m, 29.53 ft / 9.00 m
- Aft deck: 35.00 %, 29.53 ft / 9.00 m, 29.53 ft / 9.00 m
- Quarter deck: 15.00 %, 29.53 ft / 9.00 m, 29.53 ft / 9.00 m
- Average freeboard: 29.53 ft / 9.00 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 93.7 %
- Above water (accommodation/working, high = better): 284.7 %
Waterplane Area: 40,798 Square feet or 3,790 Square metres
Displacement factor (Displacement / loading): 186 %
Structure weight / hull surface area: 104 lbs/sq ft or 506 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.93
- Longitudinal: 1.87
- Overall: 1.00
Adequate machinery, storage, compartmentation space
Excellent accommodation and workspace room
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

With the Royal Marriage to the Aztecs, and increasing links to Wilno,
there is a perceived need for a new "Royal Mail"
style vessel to deliver passengers or cargo at speed over long distances.

Cruise speed is meant to be maintained on 75% oower indefinitely.
Metagame : That seems a reasonable buffer for machinery reliability, but limits top speed to 24knots, reducing the reasonableness to be magically transformed to a stealth carrier.

High Cruise speed is thought to offer protection against subs and interception. The vessel will move over 1000nm in 2 days.

Crucially, the ship will steam 12,000nm in 23 days.

A TDS is mounted, meant to prevent mines and aerial torpedos from dealing critical damage. An AA Battery is mounted, with a secondary capacity against the unlikely pirate, or more likely destroyer that catches the vessel.
Against cruisers, surrender would be the option.

Normal Displacement : 18,942
2% = 378 military equipment allowed

273 TDS
95 Guns, Mounts, Armor
-----
368

Motive Power

Engines : 1203 * (1+0.3+0.25) = 1865 total
662 misc

Range : 7632 * 1.9 = 14,500.8nm
This allows a high speed run to the other side of the world.

Misc weight
50t - Reserve

AD
95t - Fire Control 1930
25t - LR Radio
0t - SR Radio
25t - Hulesmeyer proximity detector

OD
5t - Paravanes
200t - 10 VIP passengers
2000t - 250 1st Class passengers
30t - Mail Plane (Walrus-style amphibian)
5t - Catapult on fantail.

HAW
5t - Hanger in Stern
1000t - 250 2nd Class Passengers
1000t - Cargo
30t - CO2 compressor AC
15t - Extra Fire Ext.

HBW
2000t - Cargo
15t - Extra Pumps
15t - Extra Fire Ext.
662t - Diesel-Electric Drive

Decks

9.00 Weather Deck
6.50 3rd Deck
4.00 2nd Deck
1.50 Main Deck
-1.00 1st Deck
-4.75 Engineering
-5.76 Double Bottom
-6.00 Keel

Kaiser Kirk · October 04, 2024, 09:23:57 AM

I have scores of small aux ships - sloops and gunboats- which are generally assigned to Coast Guard squadrons and provide localized law enforcement and wartime auxiliaries. These all tend towards 500 ton maxs so I can build them in 6 months.

I was thinking a larger vessel, more capable of deep ocean operations and solo operations might be nice to have in the arsenal. Kinda doubt I can find the BPs for it. But...

QuoteEnter ship name, Parthian Fleet Auxiliary laid down 1935

Displacement:
   900 t light; 942 t standard; 1,050 t normal; 1,137 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (259.19 ft / 252.62 ft) x 36.09 ft x (7.38 / 7.86 ft)
   (79.00 m / 77.00 m) x 11.00 m x (2.25 / 2.40 m)

Armament:
2 - 3.54" / 90.0 mm 54.0 cal guns - 24.25lbs / 11.00kg shells, 300 per gun
     Dual purpose guns in deck mounts, 1935 Model
     2 x Single mounts on centreline, forward evenly spread
      1 raised mount
8 - 1.18" / 30.0 mm 80.0 cal guns - 0.94lbs / 0.43kg shells, 3,000 per gun
     Anti-air guns in deck mounts, 1935 Model
     4 x 2-gun mounts on side ends, evenly spread
      4 raised mounts
Weight of broadside 56 lbs / 25 kg

Armour:
- Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.79" / 20 mm     -           -
   2nd:   0.31" / 8 mm     -           -

Machinery:
   Diesel Internal combustion generators,
   Electric motors, 2 shafts, 4,893 shp / 3,650 Kw = 20.00 kts
   Range 2,500nm at 16.00 kts
   Bunker at max displacement = 195 tons

Complement:
   91 - 119

Cost:
   £0.279 million / $1.116 million

Distribution of weights at normal displacement:
   Armament: 16 tons, 1.5 %
     - Guns: 16 tons, 1.5 %
   Armour: 5 tons, 0.5 %
     - Armament: 5 tons, 0.5 %
   Machinery: 139 tons, 13.2 %
   Hull, fittings & equipment: 437 tons, 41.6 %
   Fuel, ammunition & stores: 150 tons, 14.3 %
   Miscellaneous weights: 304 tons, 29.0 %
     - Hull below water: 102 tons
     - Hull void weights: 62 tons
     - Hull above water: 9 tons
     - On freeboard deck: 56 tons
     - Above deck: 75 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     3,291 lbs / 1,493 Kg = 148.0 x 3.5 " / 90 mm shells or 1.3 torpedoes
   Stability (Unstable if below 1.00): 1.28
   Metacentric height 1.7 ft / 0.5 m
   Roll period: 11.6 seconds
   Steadiness   - As gun platform (Average = 50 %): 76 %
         - Recoil effect (Restricted arc if above 1.00): 0.06
   Seaboat quality (Average = 1.00): 1.62

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.546 / 0.555
   Length to Beam Ratio: 7.00 : 1
   'Natural speed' for length: 15.89 kts
   Power going to wave formation at top speed: 57 %
   Trim (Max stability = 0, Max steadiness = 100): 47
   Bow angle (Positive = bow angles forward): 20.00 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 %, 18.04 ft / 5.50 m, 15.58 ft / 4.75 m
     - Forward deck:   30.00 %, 15.58 ft / 4.75 m, 13.12 ft / 4.00 m
     - Aft deck:   35.00 %, 13.12 ft / 4.00 m, 13.12 ft / 4.00 m
     - Quarter deck:   15.00 %, 13.12 ft / 4.00 m, 13.12 ft / 4.00 m
     - Average freeboard:      14.18 ft / 4.32 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 60.7 %
      - Above water (accommodation/working, high = better): 181.7 %
   Waterplane Area: 6,339 Square feet or 589 Square metres
   Displacement factor (Displacement / loading): 168 %
   Structure weight / hull surface area: 44 lbs/sq ft or 213 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.88
      - Longitudinal: 3.28
      - Overall: 1.00
   Excellent machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Warning: Beam between bulkheads too wide

Potential General Auxiliary Hull

Goals :
- Faster than a surfaced submarine
- More powerful than a porpoise
- leap through the waves in single bound (seakeeping)

Other goals :
18 month (3 HY) build time = 900 tons maximum displacement
BP cost evenly dividable by 4 (0.9/4 = 2.25, ok!)
2200+nm range for transit between bases
Cruise @ 75% max speed
Fit in 80m docks

Need 1520 / 3/4 = 2027shp for cruise = 17.25
Need 17+2-3kts higher for > Sub

Military Spec
Normal Displacement : 1050tons
2% = 21t

Engines
139 * (0.3+0.25) = 77

Range : 2500 * (1+.75+.15) = 4750nm

Miscellaneous Weight
Reserve
62t

AD :
2t - FC 1930
25t - LR Radio
0t - SR Radio
23t - Cage Mast
25t - Hulesmeyer proximity detector

OD :
5t - Paravanes
20t - DC
6t - 6 x DC Throwers
25t - MSW Gear

HAW:
9t - CO2 compressor AC

HBW :
10t - Sonar
15t - Enhanced Hydrophones
77t - Diesel-Electric Drive

Jefgte · October 04, 2024, 10:10:07 AM

Quote...BP cost evenly dividable by 4 (0.9/4 = 2.25, ok!)...

0.225 BP & $.

Kaiser Kirk · October 04, 2024, 10:37:27 AM

correct , and $ :)

I do not mind 'rounding' up fractional $ costs,
but I like my BP to be even x.xx numbers when I can...and remember to plan for.

TacCovert4 · October 04, 2024, 09:32:27 PM

Looks good. Very similar in form and function to my OPVs (the 28 and 33 series). Good all around escort for convoy duty and general purpose coastal patrolling, but still enough to go across the open ocean. Enough AA to slot into a convoy's AA screen, and enough surface guns for a couple of them to make a credible threat to a DD. Only real difference is that my OPVs have a brace of torpedoes to give them a credible surface threat in the event they get jumped by a proper surface raider.

Kaiser Kirk · October 04, 2024, 10:55:17 PM

If I skipped gun shields I could fit a pair of 18" torps and still be under 21 tons.

I have done similar in the past, and have gone with underwater bow tubes, as they could present a small (bow on profile), which lines up with their DP guns - and not have obvious launches. Underwater tubes historically didn't function past roughly 20 knots, so counter-indicated for fleet vessels, but practical for these.

The other side of that is - do I think surface combatants or strafing aircraft are more likely ?

I am not so worried about 18" in my supply lines, I have them already, plenty of bases and fleet support ships. But I also wonder about the 'storyline' aspect in that I do not know how much or little ongoing maintenance torpedoes needed. Would a dedicated torpedo specialist, or team of them, be needed on the auxiliary to keep them ready and use them properly? Conceptually I view my auxiliaries as staffed by a Naval cadre ~1/4 of the crew, with reservists rounding out the numbers. In Peacetime, the Naval cadres are probably concentrated on one active vessel, while others are tied up in standby.

Kaiser Kirk · October 13, 2024, 03:51:39 PM

The following is a long document I wrote mainly for myself, considering the design foes and goals for my next ACs .

Comments/corrections/observations are welcome.

In 1935 I am continuing work on a wide variety of ships,
and coming close to finishing my 3rd & 4th "Light Armored Cruiser".

The category that seems to need help is the standard 'armored cruiser' or 'heavy armored cruiser'.

Big enough to quickly and decisively beat cruisers, fast enough to be hard to chase down,
and small & cheap enough that they can be risked outside the layers of protection around a battleline.
These are the scout squadrons, the skirmishers, the detached mission ships.

The question is ...what to design against?

Japan's fleet is hard to tell.

So I could see versions of the 'Amagi' design and particularly the B-65 design being built.

The B-65 seems perfectly suited for an asymmetric approach, armed with 3T3 310mm, a 180mm belt and 125mm deck, and 33knts.

That ship could choose to engage or not engage any part of my fleet, it's 310mm guns will be superior to my AC's 255mm and it's deck would be fairly proof against even my battleline at range. Foxy might have gone with the 105mm deck of his last battleships as he wasnt' keen on armor, but 105mm would also future proof it against dive bombers so I can see him spending that tonnage.

From what Tac's shared, and what I saw of Foxy's designs and statements, an asymmetrical fleet would be his goal. He seemed to want to pick a fight with Parthia. I can't see him investing in a bunch of big slow battlewagons- Japan lacks the BP to compete there. A limited number of big heavy ships fast enough to avoid mine or choose to fight at range, and a great deal of smaller ships meant for night and torpedo actions. All of which would be expected to work with his carriers once he got them.

The torpedo attack role is difficult, at range the hit % drops dramatically. As the doc on NavWeaps demonstrates, in WW2 the IJN did not achieve a good enough hit rate to have made their warplan viable. The hit % gets even worse if the earliest battles where the 'long lance' was not suspected are eliminated. You need lots of ships, lots of torpedoes, night time and speed to get in close. Which Parthia has tried to make very hard to do, and then Parthian ships can soak up a lot of torpedoes.

The Byzantines Heavy Armored Cruisers have not really been replaced and are ageing.
They have made a pair of 29 knot full-size battleships, but if those are put as scouts or heavy support, the existing Stormbringer class should still suffice to stiffen the skirmish lines. Between the Byzantine and Roman ships, the Parthians may wind up building some 30knot battlewagons to compete.

The Romans are expected to support the Byzantines in a conflict due to a presumed secret part of the Malta treaty. It's a bit hard to tell what the Roman fleet would be,
but it looks like Snip's aiming for a speed around 30 knots- he tends to overshoot.
240mm guns+cruiser protection for the ACs and 340mm + battleline protection for the BCs- really fast battleships.

Analysis :
To keep the Byzantines/Romans from running my ships down I will need 30-31 knots.
To CATCH them, I need 33 or so.
The Japanese B-65 type would be 32-33 knots, so I'm not catching or getting away from that. I just have to beat it.

Deck hits really don't matter
Belt hits vs. the cruiser proof armor of the Romans and Japanese are valid. Ironically vs. an IJN Night attack, most hits would be vs. belts

The question is what it takes to penetrate battleline level armor...and that's really big guns that drive the costs way up, at which point the ship can't be purchased in great numbers, and is a bit too valuable to risk.

So I need guns that can kill the B-65 (180mm), a 1926B (165mm) or a Respublica clone (240mm), or perhaps even an Eupatoria (320mm) style follow on design. The 37,000 ton Konias are fast battleships. Then there's the variety of Byzantine 6x343 AC designs with ~200-230mm belts. Oh and the 'Colonial Battleships' with 300mm belts.

There's 3 guns under consideration for this
The 333L43 has quite a lot of 'punch', and would work on everything except the Konia, and even them at reasonable fighting ranges.

The 300L47 was developed as a hedge. It has about 20mm more belt penetration than the 265mm at most ranges. Deck penetration is 28% better, but there won't be penetrations under ~25km, and the hit rate from 25-30km is expected to be low enough that it would not be decisive.

The 265mm gun was hoped to be the next ACR gun. To get the shell weight/penetration desired had to move up from the 255mm.
Granted, it can only punch through Byzantine/Roman battleline belt armor at night time combat ranges, but I am not looking for my ACs to fight BBs. They could close to range and fight the Byzantine Colonial Battleships.

Against their intended foes - other 'ACs' and Cruisers – such as a Hypothecal B-65, they should be able to punch through their AC belts under ~23km, and start penetrating decks beyond that.

4 x 31,000 = 124,000 tons if the IJN has 4 x B-65.
= 4.3 Dahae "R"
= 5.2 Zambag VIII
= 6.5 Zemaka II

Jefgte · October 13, 2024, 04:11:17 PM

For info:

Quote... Oh and the 'Colonial Battleships' with 300mm belts...

Byzantine Colonial 24kts BBs are:

Atlantique BB9 Koloni - Kumkoy - 2T3x381
Atlantique BB4 Alexander - Leonidas - 8x343
Atlantique BB4 Pericles - Constantin - 8x343
Australia BB3 Kilkis - Lemnos - 6x343
Madagascar BB7 Kalin - Kurnaz - 6x343

Old PDNs with 254/45 guns are nearly all scrapped.

Kaiser Kirk · October 13, 2024, 07:02:02 PM

I think I had forgotten about the Koloni class being 381mm, I think of them all as 343mm.

But yes, those have long been a consideration for me. They are part of why I have bothered to rebuild my older BBs & DNs. That and I think they can stand in battle vs. NPCs and the IJN.

I'd like to build more of my Frawar class BBs to do the same role. But I built 1...and scrapped 2 Tortoise BBs.

Looking at my available BP in 1935, and more as the Xiyons complete, I may lay down 3-4 hulls,
one of which may be a Frawar.

Kaiser Kirk · October 16, 2024, 12:17:05 AM

The interwar B-65 that the IJN looked at building was late 1930s, but aimed at the same goals I think would appeal to Foxy - big and fast enough to catch my cruisers and my Armored Cruisers, but uncatchable by my battlewagons. Having the foe field ships that can hunt down my lighter units easily would be annoying.

The B-65 supposedly had :

Type:	Super Type A cruiser
Displacement:	Standard: 31,905 t (31,401 long tons)[1]
Full-load: 35,000 t (34,000 long tons)
Length:	240 m (790 ft) length at the waterline[1]
246.2 m (808 ft) length overall[1]
Beam:	27.2 m (89 ft)[1]
Draft:	8.8 m (29 ft) (trial)[1]
Propulsion:	Four sets of geared turbines and eight Kampon boilers would yield 170,000 metric horsepower (167,674 shaft horsepower); this would have been able to drive the ship at 34 kn (39 mph; 63 km/h)[1]
Endurance:	8,000 mi (13,000 km) at 18 kn (21 mph; 33 km/h)[1]
Armament:	9 × 310 mm (12.2 in)/50 caliber guns (3×3)[1]
16 × 100 mm (3.9 in)/65 caliber dual-purpose guns (8×2)[1]
12 × 25 mm (0.98 in) anti-aircraft guns (6×2)[1]
4 × 13 mm (0.51 in) machine guns (2×2)[1]
8 × 610 mm (24 in) torpedo tubes (4×2)[1]
Armor:	Sources do not give any specifics outside of a 190 mm (7.5 in) side belt sloped at 20° and 125 mm (4.9 in) deck[1]

The Brits thought 2-3 knots margin of speed was needed to ensure a usable speed advantage. For Foxy that would be 31-33 knots over my 29knot and 30knot cruisers.

Presuming he made the first class in 1924-26, they would be 31+ knots,
but once the Royal Nisseans came out they would need to be 32+ knots.

Mid - late 1920s, it would be very expensive tonnage wise to drive a ship that fast.
The Romans showed it's doable with their fast big ships. The 33-34knots the IJN was looking at are probably not feasible at this time frame.

Overall I think he would try to minimize tonnage, and try to keep speed and guns over armor.
So 31-32 knots, but less deck armor, say 4", but perhaps down to 2.5-3" as he'd simply plan on
not fighting my battlewagons, so that would drop the deck armor needed. I don't think he'd drop much below because he'd be looking to what was needed against divebombers years ahead.

The Zemaka class and rearming the Asbara would have given me something to oppose these,
so late 1920s / Early 1930s the 2nd batch of B-65s would seem likely, adding speed and perhaps a little deck armor.

Kaiser Kirk · October 17, 2024, 12:28:29 AM

While this is basically self-musing over the options,

Others comments are of course welcome.

The range of potential vessels to face these opfors span 10,000 tons.
Over the course of 4 ships, that's 40,000 tons - a battleship or a cruiser division.
I'd actually like to build more, but 4 is what I need to replace those ageing out.

I could even build mixtures, as I tend to field them in 2 ship groups.
Perhaps 2 Dahaes and 4 Zemakas? 8 Zemakas? 6 Zambags?

So there's a range. The Zemakas are the Armored Cruisers, but they should be able to take on the IJN's version of the B-65, or most of the ships discussed above- though the fast battleships would have to be a night combat. The 265mm I developed specifically because it would be 'good enough'.

The Zambags have the 300L49 gun, which was designed to be slightly larger, but slightly better vs. belt and a fair bit better on Decks.

The Dahaes depart from the 31 knot speed for a 30 knot speed.
As 'Heavy Armored Cruisers' they are the Parthian version of a battlecruiser but we aren't calling them that. As a result, they are powerful enough they don't really need to run from much. The 333L43 was designed mainly to regun the 345L40 ships, but also as it has a decent mix of penetration characteristics.

From memory, I think the 50/50 belt/deck hit spot is ~16km, while seeing the whole ship is 18km, and mast tops were somewhere from 21-23km depending on the ships. Historically the longest hits were ~26km.

Searchlights are ~12km, starshell 16km...I would need to check that. But 16km would seem about the outer band for night engagements.

Of course weather can bring all those ranges in and make long range fire impractical.

Interestingly (well to me) the specs on the Dutch 1047 BC included accelerating from 20knots to 30knots in 15 minutes. I looked at Nevada at Pearl and came up with 1knt/min as I recall. Might be 1 knt/2min. Either way, not hideously off.

Anyhow as I ponder, I post up some of the SS designs. Probably not all of them.

Horizontal

Vertical

Gun

Shell

Velocity

180mm

200mm

230mm

320mm

50mm

75mm

100mm

125mm

265L49

339kg

850mps

27km

25km

22km

16km

22km

26km

28km

never

300L49

490kg

779mps

29km

27km

24km

17km

20km

23km

26km

28km

333L43

605kg

794mps

all

29km

25km

18km

20km

24km

27km

29km

Horizontal

Vertical

Max

Cruise

Class

Light Tons

Main Btty

Sec Btty

Magazines

Machinery

Magazines

Machinery

TDS / Torps

Speed

Range

Zemaka II

19000

8x265L49

12x130DP

267

232

116

83

4m / 4.9

31

16

8146

Zemaka III

19750

8x265L49

12x130DP

267

232

116

83

4m / 5.5

31

18

10142

Zambag XV

23000

8x300L49

16x130DP

267

232

116

83

4m / 5.9

31

18

8184

Dahae Q

26000

8x333L43

16x130DP

349

309

123

105

6.5m / 8.2

30

16

8744

Zambag IX

26750

8x300L49

16x130DP

331

294

125

87

4m / 7.9

31

18

9894

Dahae R

27000

8x333L43

16x130DP

376

339

148

110

6.5m / 8.5

30

16

8396

Dahae S

28770

8x333L43

16x130DP

376

339

148

110

5m / 8.1

31

16

8084

Kaiser Kirk · October 18, 2024, 03:30:50 PM

So this is the 'Zemaka III' from the above table.

The key of moving from 255mm to 265mm was that with the new tech I could fire a shell weighing the same as a 12" shell, but with a 10.5" cross-section.

I provided a very high number of shells for the main guns. You'll see that on the Zambag as well.
I am concerned that if ships try to fight at very long ranges, the 'to hit' % will be very low.
As I expect it is divided between AP, SAP and HE shells, a long battle with low hit rate might run me low in a shell size.
The other aspect is if these ships are sent on individual runs, they may have to fight more than one battle.

Overall a design choice I'm still debating.

I think the 1/4 more range at higher speed is 'worth' 750 tons.
Granted that's 1,250tons more than the Zemaka I, which is not desirable. That's a destroyer.

The II ships 3500t fuel oil, the III has 5973t, that additional hull volume also giving more floatation adn >5.0 torpedoes.

QuoteZemaka III, Parthian Armored Cruiser laid down 1935

Displacement:
   19,750 t light; 21,237 t standard; 24,555 t normal; 27,210 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (617.53 ft / 610.24 ft) x 78.74 ft (Bulges 85.30 ft) x (30.18 / 32.90 ft)
   (188.22 m / 186.00 m) x 24.00 m (Bulges 26.00 m) x (9.20 / 10.03 m)

Armament:
8 - 10.43" / 265 mm 49.0 cal guns - 747.37lbs / 339.00kg shells, 180 per gun
     Breech loading guns in turret on barbette mounts, 1935 Model
     2 x 4-gun mounts on centreline ends, evenly spread
12 - 5.12" / 130 mm 47.0 cal guns - 85.98lbs / 39.00kg shells, 360 per gun
     Dual purpose guns in deck and hoist mounts, 1935 Model
     2 x 2-gun mounts on centreline ends, evenly spread
      2 raised mounts - superfiring
     4 x 2-gun mounts on side ends, evenly spread
32 - 1.46" / 37.0 mm 70.0 cal guns - 1.72lbs / 0.78kg shells, 5,000 per gun
     Anti-air guns in deck and hoist mounts, 1935 Model
     6 x 2 row quad mounts on side ends, majority forward
      6 raised mounts
     2 x 2 row quad mounts layout not set
      2 double raised mounts
32 - 0.91" / 23.0 mm 90.0 cal guns - 0.44lbs / 0.20kg shells, 5,000 per gun
     Anti-air guns in deck mounts, 1935 Model
     16 x Twin mounts on sides, evenly spread
      16 double raised mounts
Weight of broadside 7,080 lbs / 3,211 kg

Armour:
- Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   7.09" / 180 mm   396.65 ft / 120.90 m   16.99 ft / 5.18 m
   Ends:   1.38" / 35 mm   213.55 ft / 65.09 m   8.20 ft / 2.50 m
     Main Belt covers 100 % of normal length
     Main Belt inclined -15.00 degrees (positive = in)

- Torpedo Bulkhead - Additional damage containing bulkheads:
      2.24" / 57 mm   396.65 ft / 120.90 m   28.97 ft / 8.83 m
   Beam between torpedo bulkheads 59.06 ft / 18.00 m

- Hull Bulges:
      0.35" / 9 mm   405.18 ft / 123.50 m   23.29 ft / 7.10 m

- Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   10.0" / 255 mm   4.72" / 120 mm      8.27" / 210 mm
   2nd:   2.56" / 65 mm   1.38" / 35 mm      1.97" / 50 mm
   3rd:   0.31" / 8 mm     -           -
   4th:   0.31" / 8 mm     -           -

- Armoured deck - multiple decks:
   For and Aft decks: 4.20" / 107 mm
   Forecastle: 1.38" / 35 mm Quarter deck: 2.56" / 65 mm

- Conning towers: Forward 7.09" / 180 mm, Aft 1.38" / 35 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 4 shafts, 124,468 shp / 92,853 Kw = 31.00 kts
   Range 10,142nm at 18.00 kts
   Bunker at max displacement = 5,973 tons

Complement:
   980 - 1,275

Cost:
   £9.014 million / $36.056 million

Distribution of weights at normal displacement:
   Armament: 1,474 tons, 6.0 %
     - Guns: 1,474 tons, 6.0 %
   Armour: 6,617 tons, 26.9 %
     - Belts: 2,116 tons, 8.6 %
     - Torpedo bulkhead: 954 tons, 3.9 %
     - Bulges: 124 tons, 0.5 %
     - Armament: 846 tons, 3.4 %
     - Armour Deck: 2,422 tons, 9.9 %
     - Conning Towers: 154 tons, 0.6 %
   Machinery: 3,536 tons, 14.4 %
   Hull, fittings & equipment: 7,587 tons, 30.9 %
   Fuel, ammunition & stores: 4,805 tons, 19.6 %
   Miscellaneous weights: 537 tons, 2.2 %
     - Hull below water: 50 tons
     - Bulge void weights: 116 tons
     - Hull above water: 48 tons
     - On freeboard deck: 65 tons
     - Above deck: 258 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     34,601 lbs / 15,695 Kg = 60.9 x 10.4 " / 265 mm shells or 5.5 torpedoes
   Stability (Unstable if below 1.00): 1.11
   Metacentric height 4.3 ft / 1.3 m
   Roll period: 17.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.61
   Seaboat quality (Average = 1.00): 1.01

Hull form characteristics:
   Hull has rise forward of midbreak,
     a ram bow and small transom stern
   Block coefficient (normal/deep): 0.547 / 0.556
   Length to Beam Ratio: 7.15 : 1
   'Natural speed' for length: 26.84 kts
   Power going to wave formation at top speed: 61 %
   Trim (Max stability = 0, Max steadiness = 100): 69
   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:   20.00 %, 27.23 ft / 8.30 m, 26.57 ft / 8.10 m
     - Forward deck:   44.00 %, 26.57 ft / 8.10 m, 25.92 ft / 7.90 m
     - Aft deck:   21.00 %, 17.72 ft / 5.40 m, 17.72 ft / 5.40 m
     - Quarter deck:   15.00 %, 17.72 ft / 5.40 m, 17.72 ft / 5.40 m
     - Average freeboard:      23.29 ft / 7.10 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 96.2 %
      - Above water (accommodation/working, high = better): 156.4 %
   Waterplane Area: 34,263 Square feet or 3,183 Square metres
   Displacement factor (Displacement / loading): 124 %
   Structure weight / hull surface area: 153 lbs/sq ft or 747 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.92
      - Longitudinal: 1.95
      - Overall: 1.00
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

The Zemaka II is the follow on to the 'Zemaka' aka 'Storm Winds' class.

Weaponry :

The 265L49 gu9n fires a 339kg shell at 850mps - that's as fast as I'll allow for large guns
as real life guns over this were generally derated becuase they stripped their rifling.
A slightly lower limit could be argued for, but as I run alot of the battles, I want to give player designs the benefit of the doubt. The guns could always be derated in service to ~825mps
if the 'game master' felt that was the maximum reasonable.

The shell weight is about that of a 12" shell, but with a smaller cross section, so less wind drag and more Kinetic Energy at impact. This gives very good belt penetration.

The deck penetration is not great because the shell does not plunge, but the shell is heavy enough to compensate. Worse case, they could do what the USN did and simply have a range table for firing the gun with 1 less bag of powder to cause a lower MV.
This is not seen as a serious flaw as gains in deck penetration tend to be slow and at the outer limits of accuracy. Barring catastrophic hits, two ships might seriously deplete their magazines at very long ranges without landing enough hits to reduce the foe to a sinking condition.

3 5
(b) (d) (f)
A (1) [a] z (6) Y
(c) (e) (g)
2 4

Armor :
The armor scheme is unusual for a Parthian ship.

A main armored deck is mounted at the top of the belt.
But a protective armored deck for splinters crowns above the waterline and connects to the bottom of the belt.
The TDS seals to the 'knuckle' of the protective deck.

A magazine box meets the protective deck, thickening the plates over the magazine.

Belt
Inclined Waterline Main belt is backed by a protective deck, the TDS, and then the magazine box.

Inclined belt :
5m/ Cos (15) = 5.17638 = 5.18

Math :
180 + 35*1.5/2 + 57/2 + 65/2

Waterline
Magazines : 267mm + slope
Machinery : 232mm + slope

Deck

Vertical :
Main + 1/2 protective + 1/2 magazine

Magazines : 115mm
Machinery : 83mm

1568t 35/65/65mm Armored Deck
717t 0/35/0mm Protective Splinter Deck
136t 65mm Magazine Box - meets bottom of protective deck
------
2,421t needed

2,422t paid

MISC :
116- Reserve wt.

AD :
148t FC 1930
25t LR radio
0t SR Radio
10t RDF/Jammer
25t Hulesmeyer
25t Air Search Radar
25t Searchlight tower (NF)

OD :
5t - Paravanes
10t - 2x Catapults on stern
50t - 2x Floatplanes on stern

HAW :
10t - Hanger in stern
19t - CO2 Air compressor A/C
19t - Extra Fire Extinguishers

HBW :
19t - Extra Pumps
31t - Auxiliary Diesel Generator power

Decks
7.9m : Forecastle
5.40 : Weather
2.90 : Battery, Top Main belt, Armored Deck
0.40 : Main deck, splinter protective deck, top TDS
-2.1 : 2nd deck. Bottom Main Belt
-4.6 : 1st Platform deck
-6.1 : Engineering
-8.08 : Double bottom
-9.20 : Keel

Kaiser Kirk · October 18, 2024, 03:45:26 PM

This would be the Zambag XV

Same armor scheme as a Zemaka, so meant to take on cruisers and armored cruisers, not battlecruisers/fast battleships.

The 300mm gun is an overweight shell with lower MV, so the belt penetration is similar to the 265mm, but the deck penetration is much better. While it still can't penetrate most battleship's deck armor, it can penetrate anything else.

Overall, a better gun than the 265mm, and again with a large magazine for sustained long range fire.

BUT...this won't kill cruisers or armored cruisers much better than the Zemaka III,
and it's protection level means it can not take on the BCs/BBs.

So I'd be paying 3000 tons more for a ship that does pretty much exactly the same task, and has 80% of the range.

QuoteZambag XV, Parthian Heavy Armored Cruiser laid down 1935

Displacement:
   23,000 t light; 24,889 t standard; 27,839 t normal; 30,200 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (617.62 ft / 610.24 ft) x 88.58 ft (Bulges 95.14 ft) x (30.18 / 32.31 ft)
   (188.25 m / 186.00 m) x 27.00 m (Bulges 29.00 m) x (9.20 / 9.85 m)

Armament:
8 - 11.81" / 300 mm 49.0 cal guns - 1,080.27lbs / 490.00kg shells, 180 per gun
     Breech loading guns in turret on barbette mounts, 1935 Model
     2 x 4-gun mounts on centreline ends, evenly spread
16 - 5.12" / 130 mm 47.0 cal guns - 85.98lbs / 39.00kg shells, 360 per gun
     Dual purpose guns in deck and hoist mounts, 1935 Model
     2 x 2-gun mounts on centreline ends, evenly spread
      2 raised mounts - superfiring
     6 x 2-gun mounts on sides, evenly spread
      2 raised mounts
32 - 1.46" / 37.0 mm 70.0 cal guns - 1.72lbs / 0.78kg shells, 5,000 per gun
     Anti-air guns in deck and hoist mounts, 1935 Model
     6 x 2 row quad mounts on side ends, majority forward
      6 raised mounts
     2 x 2 row quad mounts layout not set
      2 double raised mounts
32 - 0.91" / 23.0 mm 90.0 cal guns - 0.44lbs / 0.20kg shells, 5,000 per gun
     Anti-air guns in deck mounts, 1935 Model
     16 x Twin mounts on sides, evenly spread
      16 double raised mounts
Weight of broadside 10,087 lbs / 4,575 kg

Armour:
- Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   7.09" / 180 mm   396.65 ft / 120.90 m   16.67 ft / 5.08 m
   Ends:   1.38" / 35 mm   213.55 ft / 65.09 m   8.20 ft / 2.50 m
     Main Belt covers 100 % of normal length
     Main Belt inclined -15.00 degrees (positive = in)

- Torpedo Bulkhead - Additional damage containing bulkheads:
      2.24" / 57 mm   396.65 ft / 120.90 m   27.82 ft / 8.48 m
   Beam between torpedo bulkheads 68.90 ft / 21.00 m

- Hull Bulges:
      0.35" / 9 mm   405.18 ft / 123.50 m   23.29 ft / 7.10 m

- Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   9.06" / 230 mm   4.72" / 120 mm      8.27" / 210 mm
   2nd:   1.97" / 50 mm   1.57" / 40 mm      1.97" / 50 mm
   3rd:   0.31" / 8 mm     -           -
   4th:   0.31" / 8 mm     -           -

- Armoured deck - multiple decks:
   For and Aft decks: 4.22" / 107 mm
   Forecastle: 1.38" / 35 mm Quarter deck: 2.56" / 65 mm

- Conning towers: Forward 8.27" / 210 mm, Aft 1.38" / 35 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 4 shafts, 136,742 shp / 102,009 Kw = 31.00 kts
   Range 8,184nm at 18.00 kts
   Bunker at max displacement = 5,311 tons

Complement:
   1,076 - 1,400

Cost:
   £11.097 million / $44.386 million

Distribution of weights at normal displacement:
   Armament: 2,033 tons, 7.3 %
     - Guns: 2,033 tons, 7.3 %
   Armour: 7,183 tons, 25.8 %
     - Belts: 2,111 tons, 7.6 %
     - Torpedo bulkhead: 916 tons, 3.3 %
     - Bulges: 124 tons, 0.4 %
     - Armament: 1,081 tons, 3.9 %
     - Armour Deck: 2,760 tons, 9.9 %
     - Conning Towers: 191 tons, 0.7 %
   Machinery: 3,885 tons, 14.0 %
   Hull, fittings & equipment: 9,225 tons, 33.1 %
   Fuel, ammunition & stores: 4,839 tons, 17.4 %
   Miscellaneous weights: 674 tons, 2.4 %
     - Hull below water: 69 tons
     - Bulge void weights: 170 tons
     - Hull above water: 56 tons
     - On freeboard deck: 65 tons
     - Above deck: 314 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     38,523 lbs / 17,474 Kg = 46.8 x 11.8 " / 300 mm shells or 6.0 torpedoes
   Stability (Unstable if below 1.00): 1.13
   Metacentric height 5.2 ft / 1.6 m
   Roll period: 17.5 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.64
   Seaboat quality (Average = 1.00): 1.00

Hull form characteristics:
   Hull has a flush deck,
     a ram bow and small transom stern
   Block coefficient (normal/deep): 0.556 / 0.563
   Length to Beam Ratio: 6.41 : 1
   'Natural speed' for length: 26.98 kts
   Power going to wave formation at top speed: 62 %
   Trim (Max stability = 0, Max steadiness = 100): 70
   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:   20.00 %, 27.56 ft / 8.40 m, 25.59 ft / 7.80 m
     - Forward deck:   32.50 %, 25.59 ft / 7.80 m, 24.93 ft / 7.60 m
     - Aft deck:   32.50 %, 24.93 ft / 7.60 m, 24.93 ft / 7.60 m
     - Quarter deck:   15.00 %, 24.93 ft / 7.60 m, 24.93 ft / 7.60 m
     - Average freeboard:      25.33 ft / 7.72 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 98.2 %
      - Above water (accommodation/working, high = better): 172.7 %
   Waterplane Area: 38,877 Square feet or 3,612 Square metres
   Displacement factor (Displacement / loading): 118 %
   Structure weight / hull surface area: 172 lbs/sq ft or 842 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.91
      - Longitudinal: 2.23
      - Overall: 1.00
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

The lightest of the Zambag efforts.

3 5 7
(b) (d) (f)
A (1) [a] z (6) Y
(c) (e) (g)
2 4 6

Armor :

Belt
Inclined Waterline Main belt is backed by a protective deck, the TDS, and then the magazine box.

Inclined belt :
+2.8 to -2.1m
4.9m/ Cos (15) = 5.07285= 5.08

Math :
180 + 35*1.5/2 + 57/2 + 65/2

Waterline
Magazines : 267mm + incline
Machinery : 232mm + incline

Deck

1780t 35/65/65mm Armored Deck
813t 0/35/0mm Protective Splinter Deck
167t 65mm Magazine Box - meets bottom of protective deck
------
2,760t needed

2,760t paid

Vertical
Magazines : 133mm
Machinery : 83mm

MISC :
170t- Reserve wt.

AD :
204t FC 1930
25t LR radio
0t SR Radio
10t RDF/Jammer
25t Hulesmeyer
25t Air Search Radar
25t Searchlight tower (NF)

OD :
5t - Paravanes
10t - 2x Catapults on stern
50t - 2x Floatplanes on stern

HAW :
10t - Hanger in stern
23t - CO2 Air compressor A/C
23t - Extra Fire Extinguishers

HBW :
23t - Extra Pumps
31t - Auxiliary Diesel Generator power 500ke
15t - Enhanced Hydrophones

Decks
7.6m : Forecastle
5.20 : Weather
2.80 : Battery, Top Main belt, Armored Deck
0.40 : Main deck, splinter protective deck, top TDS
-2.1 : 2nd deck. Bottom Main Belt
-4.6 : 1st Platform deck
-6.1 : Engineering
-8.08 : Double bottom
-9.20 : Keel

TacCovert4 · October 18, 2024, 04:22:45 PM

How will they match up against "HMS Courageous but with more HMS Courageous"? I'm working on a ship design with Foxy's input.....and that's the direction he's going for a carrier escort capital ship.

Kaiser Kirk · October 18, 2024, 04:59:14 PM

Quote from: TacCovert4 on October 18, 2024, 04:22:45 PMHow will they match up against "HMS Courageous but with more HMS Courageous"? I'm working on a ship design with Foxy's input.....and that's the direction he's going for a carrier escort capital ship.

No clue, I'd have to see it.
I was guessing he'd go fast and light, which is why I was looking at the B-65 and Dutch 1047.
The problem with HMS Courageous is even my existing 215mm-255mm ACs can kill it most of the time.

4 Barrels has a substantial FC penalty without aerial spotting, and even with, that's a low max ROF.
Now if you are far enough out, ROF declines so you can adjust. But that ship doesn't have a ton of deck armor either.

Overall, guessing fairly darn well, as they are nearly the same speed, but with twice the barrels and higher ROF, so they would punch many many holes in HMS Courageous armor before it got a any hits. They would both punch right through each other, so more holes the better.

The 'Heavy Armored Cruiser' designs would just dominate an HMS Courageous style ship, though they outweigh it. I will probably post one of those 4 designs once I decide which is best suited for my needs.

But it might be a good reason to delay my making a decision.