Parthian vessels 1916 onwards

[Jefgte]

They are in the same spirit as the Byzantine projects for 1924:
2T3x191 - 32kts & 3T3x191 - 32kts.

;)

[The Rock Doctor]

It looks powerful on paper but I remain skeptical that a mount-and-hoist with such heavy projectiles will be effective.

[Kaiser Kirk]

A) I rather expected the Byzantines would have something similar

B) The weight problems are ones the Parthians are concerned with...and I've tried to ensure the mountings will at least be 'adequate'.

The historical Pensacola class was 8"/55 in mount & hoist
but the US laid down a whole bunch of the Pensacolas and their successors before the first were in service.
Then on the next class...they went for proper turrets

Which to me says the Pensacola's mounts were not entirely satisfactory.
edit : generally I do not view the fact they ordered or made something as proof it worked well or was a good idea.
It's if after having it in service a bit, they order more like that.   


Here, I've tried to do several things to change that answer.
1.  a 180L47 is far lighter than a 203/55. The 3-gun vs triple is 152t vs. 212t  Even with the armor, the overall structure is lighter.   
2.  That weight is still 'high', which is why the mounts were researched as designed for power assist
2.  While I could have gone with the 90kg shell, I went with the 85kg, keeping it at the upper limits, and again power assist

I'm not saying I have the magic answer, it's a valid concern, that I've tried to address.

[Kaiser Kirk]

Under Ship Design, I long ago added guidelines, one is about mounting weights and shell weights.

The Parthian 3-Gun is over that 70t  before armor, and well over with.
The 2-gun is better off.
The power assist should help.
Functionally I would expect both to be able to traverse fast enough for somewhat distant targets, but - esp the 3-gun- struggle with close-in small fast targets.
Historically the 8-inch US cruisers had real problems with the night actions and short range, these should be better...but not perfect.

The Omaha-style mounts, all singles, should actually do just fine :)

As a practical matter, a mount over 45tons rotating weight will be slower to train, power assist or a turret may be recommended. This may be a Twin 152mm/53, or a Single 19cm/45.   At weights over 70t, rate of train will be slow and turrets are strongly recommended.

As a practical matter, shells between 60 and 95kg are heavy and the ROF will slowly decrease as the crew gets tired.  Power assist will delay this. Hoists are highly recommended.

Shells over 90kg are difficult to handle and are slow to handload. Power hoists and ramming with a turret is recommended.

[The Rock Doctor]

I acknowledge that the guidelines provide guidance and that you're also trying to address concerns.

It's just not the path I'd take forward, I guess.

[Kaiser Kirk]

I'd be curious to hear your opinion on how to draw that line between clearly to heavy, needs turret,
and clearly doable in mount and hoist.... versus doable in M&H but only with power assist.

I really don't know. The guidelines are what I gleaned from reading comments about guns and mounts on Navweaps
and background discussions on the Washington treaty.  Then there's Furutaka with single 200mms, and the Pensacolas
exploring those boundaries.

So come one, come all, comment on where the lines should be !

Oh, and because I researched a 3-gun Mount and hoist doesn't mean I have to fit it,
if trials find it's inadequate I could always just use the 2-gun mount, which is 2/3rds the weight
...
and that's why the Omaha-variant was developed - all singles, all clearly in the weight range for use.

[Desertfox]

Personally, I wouldn't go above single8" or twin 6" for M&H. The 7" twins, I would assume, would be toeing the line but okish especially if given power assist, I could see the triples having issues in service. You can always build them as flawed ships.

Edit: I just saw the secondaries, they are... quite heavy. Do you really need all that AA and all those 120mms?

[The Rock Doctor]

I guess I see three functional differences between M&H and turrets, at least in the "modern" era:

1)  I assume M&H is manually rotated/elevated, while turrets have some sort of built-in mechanical movement on account of sheer weight. 

2)  I assume M&H shells are manually loaded once they arrive at the gun, whereas I assume the turret shells are entirely mechanically loaded.

3)  I assume the M&H below-decks protection is much more compact than the barbette.  I assume the former literally only protects the hoist itself, whereas the barbette protects the powder and shell rooms.

The difference in weight between the two types is close enough that I'm comfortable with adding 10% of mount weight to cover off the power-assist elements of #1.

If power-assist is meant to also capture the loading process, then I dunno.  My admittedly limited reading suggests that manually loading 6" was a real hassle on smaller ships (cruisers or liners, not so much), and that the British 7.5" is noted as "cumbersome".  There are certainly strong guys with good backs to recruit, but nobody's going to be speed-running the loading of hundred-pound projectiles for long (and I acknowledge that's about where the guidelines step in).

I think if you want the training and loading perks of a turret but don't want a big ring of steel under it to protect your shells and powder storage, you just go with a turret and keep the barbette at 0mm rather than M&H with extra weight.

I think my other issue is I'm not sure why a cruiser with M&H 190mm guns should benefit from a lower composite hull strength than a cruiser with those guns on barbettes. 

[TacCovert4]

I look at the difference between M&H and T&B as a bit different.

T&B has a multi-deck rotating structure with powder handling level and shell level, all on the rotating stalk and all power driven.

M&H has a single deck penetration, with a combined Powder/Shell handling space, that functions as the top of the hoist from the magazine, just below the mount itself.  The mount itself rotates on a ring, but the hoist-top and handling space remains stationary.  These are manual spaces with a power hoist and powder/shell tray.  Basically the powder and shell ride the hoist up to the handling point, then are manually shifted onto a tray that's on the orientation of the gun itself (as the hoist doesn't reorient to the gun like a barbette's rotating structure does).

I agree that M&H is 'unpowered, power ready'.  Adding in power equipment adds in electric traverse and elevation, so now the mount can be power driven to track with the fire control.  I also treat powered M&H as having power ramming, a powered ram that rotates over and rams the shell and powder off the tray into the gun before the breech is closed manually. 

Basically an electrified Mount and Hoist has the powder and shell move up to the handling space via the powered hoist, get manhandled onto the loading tray, power rammed into the breech, breech is closed manually, and traverse and elevation is done electrically.

[Kaiser Kirk]

I'm happy to see a conversation,
unfortunately, I got busy last night, then everything today ran long
and I have an out of town trip Thus,
so I'll chime back in Friday , debate away !

[The Rock Doctor]

I dunno, I said my bit but will go with whatever the rules are.

[Kaiser Kirk]

I was hoping to encourage folks to share knowledge.

Several bits
A) Guidelines <> Rules
The Ship Design bit by Snip - those are rules.
The Guidelines part... they aren't called rules - just guidelines.
They were meant to be like hints as we added new players who might want to know general limits.
They currently are just based on what I've gleaned, and snip chimed in...but I do not pretend
to get it perfect ! 

SO they certainly open to being added to or modified based
on better knowledge. 

B) Intent
I expect the hoist element has a narrowed armored column connecting down to the armored deck, with a flashproof door connecting to the handling room.

My intent was to provide power assist for elevation and train,
and power ramming. Putting aside 10% actually seems high to me,  thought about 5%, but I wanted to clearly pay 'more than enough'.
HMS Hawkins  7.5" were 46ton and took a 10hp motor, which I would be astounded if it weighed 4.6tons.

C) End results
I think the 3-gun +armor is likely pushing 'too far' in terms of rotating weight. On borderline of mistake or not.
Pensacolas triple worked with limitations, but slow traverse is acceptable in long range combat.
The USN went to turrets later and fitted more armor on them.

A redeeming factor is I researched two 3-gun mounts so I could use the 'better' one.

I could see Parthia refitting the ship to field 4 x 2 to 'fix' that problem, or refitting the mounts with only splinter protection.

D) Background babbling

So some expounding from memory and elsewhere ..

Historically, the breakpoint seems
There were some M&H 8" weapons, but reportedly the Japanese
specifically lobbied for this for Heavy cruisers as
the shells would demand power ramming by all nations,
where a smaller gun might be handloadable by bigger Western
sailors but not the typical Japanese.
For example Pensacola's 8" was 118kg and power rammed.

Before that there was a range of the 'upper end of handloading'
often with successor guns - the French went 19cm, 194mm and 194mm.
These large handloaders and shell weights were :
French 194mm 86kg,
UK 7.5", 91kg - this is the Hawkins gun
AH 19cm 97kg,
US 7" 75kg
Italy : AH 19cm / UK 7.5"

Then there was the next step down
Germany  : 17cm 64kg
France : 164.7mm 55kg

I'm looking at HMS Hawkin's 7.5/45 mkIV.  The brits had mounted the 7.5"91kg  I-III on prior classes, and a 7" before that.
The earlier mounts seem without power assist,
I think from Navweaps they started with a simple pedestal mount, and then added power assist and ramming.
At the top it sasy "This gun and its projectiles were rather heavy for use in a simple, open mount and proved somewhat cumbersome in service." while the mount description states  "This mounting was essentially a hand-worked center pivot type with additional power training and elevation provided by a 10 HP electric motor and hydraulic pump. Run-out was spring-powered."

What's my point ?
Hmm, I had one, put it down, where is that thing...
Oh yeah - so for decades multiple navies found this shell size as the upper limit for handloading, and despite notes about crews tiring out, they were deemed good enough they seemed to have kept developing new versions and fielding them.

So power assist is nice bonus, but not required for them.


Other Issue : AA and Secondaries.
the 1924 French Cruiser Suffren had 8x 75mm, 8x 37mm, 12x MG for AA.
The proposed armament is quite similar.

Also, the entire approach I have taken in this game is Protection & Guns > Speed.
Look at my steps for torpedo defense -   
My larger ships not only have TDSs, but deep ones, with an external bulge for more depth,
and then I still add a couple hundred tons of torpedo nets. All to address that one vulnerability.
However the best torpedo defense is not getting hit - by disrupting and destroying the attackers
so I've shoved a large number of secondary guns on many of my ships.

I fully plan to take the same proactive approach with AA.
All it takes is for someone in the Navy to take the local Billy Mitchell very seriously
and proactively provide a heavy defense o this threat....for a minimal tonnage investment.

The weight is trivial, there's plenty deck space- particularly when I stick the 120mm in casements
but remember the old dreadnaughts with 20-odd 3" guns bolted on for Torpedo boat defense.


Other issue : Turret vs Mount and structural weight :
Admittedly, I didn't design the tech chart in the first place.
I know the turret part of the cruiser rules is a bit of a kludge,
so that there would be an easily enforceable spot.
Functionally, a turret has an amored barbette that extends down
and transfers the load to the keel.
The mount is supported by the deck members, and may need some
additional support, but by it's nature is a much lighter feature
and so  the ship isn't built around it in the same way,

[Kaiser Kirk]

My opinion :
Single 166-199mm : Manual traverse ok, ROF slows down in long engagements w/o Power assist
Twin/2G 166-199mm : 10% - or 5%?  Power assist needed for full capability.
Triple/3G 166-199mm : Even with power assist, won't traverse fast enough to engage for short range high speed foes.

Though really it should be tied to shell weights and rotating weights, if you put 250mm of armor on a single pedestal mount, it won't turn fast.

Anyhow, if folks have ideas on better expressing this, it could be added to the guidelines.

[TacCovert4]

I would agree with your assessment.  Technically the armor is a factor, but the armor is also right on the axis of rotation on a mount like that, and honestly isn't stupid amounts of tonnage, so the armor unless it's obscenely thick shouldn't factor in.  I'd say that singles can do just fine, with a slowdown in RoF over an extended engagement, twins need power assist to engage faster maneuvering targets and to keep RoF up, and triples need power assist (or a turret) otherwise they're really no better than twins.

[TacCovert4]

On a side note, this difference between mounts and mount/hoists is why I went with M&H for the twin 30mm AA gun.  I wanted an AA gun that could really pump out rates of fire to allow it to supplant machine guns, as machine guns aren't useful against torpedo boats before they launch (but a 30mm gun would be) and we've already seen the trend towards faster aircraft as well as zepplins and large aircraft that might not be threatened by a 'normal' machine gun.  The 30mm AA gun in M&H allows for better ammo feed as well as the supporting room (non rotating) below the gun for the gun/magazine crew to speed up feeding of the gun off the deck and out of the weather and light splinters/MG bullets.