Guns, and More Guns, and All the Guns

[TacCovert4]

Because naturally the 2nd Amendment applies to ships, everyone aboard must have a gun to man.

I'm looking at several options for my build plan going into the 30s.  Mostly in the AA and DP varieties.  As they aren't explicitly stated in the techs, I wanted to check on possibilities.

Octuple 30mm M&H.  Naturally the Octuple Pom-Pom is a possibility in real life, and I'd like to duplicate it.  I figure one this big would need the M&H with the associated powered kit that comes with that system.

2 row quad 80mm DP.  As it's still Lighter than a 2 gun 180mm, which is accepted as the upper limit of what a M&H can accommodate without being overly unwieldy, I think it's fine as a M&H.

For the more mundane, I'm looking at the following guns:

80mm DP.  This will replace a lot of the 100mm guns on older vessels, be a primary gun on small craft and auxiliaries, and will come in a single and 2 gun surface mount. 

115mm DP.  This will replace a lot of the single-purpose 130s on older vessels and be a primary gun option for DDs and a secondary gun option for larger vessels, probably in a single Deck and 2 gun M&H.

And I keep bandying the idea of a 140mm DP gun, which is the upper limit of DP.  Would be a great gun for an Dido/Atlanta style cruiser, but at this point I'm so heavily wedded to the 180mm gun that I just don't know if I can find purpose for it.

[Kaiser Kirk]

 - As long as SS has a dropdown menu for it, you can build it.  We're exploring options here.
- Octuple will take time per the rules because of the number of barrels. 
- it's multiple barrel rotary weapons that don't fit well, like Fox's 2" gatlings or my GAST 15mm...or my old handcranked twin barrel 15mms.   There's no real drop down for them, but they can be treated as a single-slide set of barrels. I am unsure how to model revolver guns.
- if the drop down gives a warning message, can't do it. So Snip is researching the 28/55 automatic, but I think he'll find that it won't model as automatic until after 1930. So on his SS it will have to be AA or MG.
- Under Ship design guidelines, way down, there's a meandering bit I wrote about which mount rotating tonnage ranges tend to get called out as problematic on navweaps and other sources I've read.  The barbette armor shouldn't matter, but the gunhouse + gun portion should.
- The twin 180 with power assist is what we are using as guess at the practical max, based on history of what seemed to work and what didn't. I personally keep the armor down, though not treaty cruiser level.
- I believe you're the one that pointed out that Pensacola had triple 8" M&H (semi-stalked) ...and lay down follow-on ships/classes before Pensacola was completed....    but my reading found that once they had them in service, they dropped that concept and ponied up the tonnage for turrets.
-Likewise numerous sources indicate that the IJN is the source of the 6" / 8" treaty break , as they felt there was a size/strength difference between IJN and European sailors, and wanted to force that upper size into a place where powered mounts were required for Europeans as well. That killed the historical 7-7.5" weapons found in many navies...which again points to 7-7.5" as the upper size/weight limit. 
- Just because a player CAN...., doesn't guarantee it was a good idea to do so....
-
History has all sorts of weapons that proved poor in service, for all sorts of reason, while others were fantastic successes. .  but maybe only in conjunction with other measures.

HMS Invincible when completed featured electric drive turrets, which were such a colossal failure that they were eventually gutted and replaced with hydraulics. Likewise she didn't have a battle practice beyond 6000 yards until WW1. Had the BCs fought Scharnhorst & Gniesenau shortly after commissioning, may have been a different end result.

HMS Renown's triple mounts (like many triple mounts) were not deemed a success.

The Brit 5.25 had all sorts of issues, overall weight and rate of traverse being some, cramped interior being another.

The Italians kept cramming barrels together in single-slide twin mounts with high velocity that led to barrel stripping and dispersion.
The 5/38 first deployed with a pedestal mount, but the ROF was high enough to make feed a problem.
But with the base ring, and later M&H it became far better, but only when paired with the best AA fire control directors did it really shine. It was noted to rotate and elevate much faster than the 5/51.

Many powers tried for mid-sized 6-8" DP ability, which just didn't work – ROF/Rate of train being fatal flaws.

For my part, I try to 'fight' these by researching extra mounts, and re-researching guns. I could just 'refresh' them as well. But with each new gun type, you'll see me take the free mounting...and then pay for one so that I develop 2 (at least) and then theoretically my Navy will use the one that works better.

Though a funny aside – the casement 5" (refitted from 5/51 to 5/38) on USS Maryland were used for AA fire against torpedo bombers. A local author wrote a book including that tidbit. 
Which Navweaps now has :
During World War II Lt. McNaughton, the secondary battery officer on USS Maryland (BB-46), obtained ten 5"/38 (12.7 cm) AA common projectiles per gun which were all set for 2 seconds fuze time. He computed and painted a table on each gun giving the necessary lead angle based upon the target angle. The gun crews trained for engaging torpedo planes and this training paid off when these guns shot down a Nakajima B5N "Kate" Type 97 torpedo plane on 18 June 1944 during the Saipan invasion.

[The Rock Doctor]

I haven't scoped out the difference in weight for DP vs. existing mounts but generally assume I'm going to stick with the existing calibers.

130mm would continue to be the most widespread, as secondaries on capital ships and primary on a lot of smaller stuff.

Maybe one or two of 50/75/100 as well, mainly for smaller patrol and river assets.

As Kirk notes, 150mm and 200mm were historically attempted but I kind of don't feel like going down retrospectively obvious dead-ends.

I suspect most of the mountings will be 1 and 2 guns, maybe quads for small weapons.  Triples were a passing fad for the Union.

I have to admit I've always thought octuple pom-poms were just overkill in a really big mount. 

[Kaiser Kirk]

Between researching these two

1914: True Quadruple turrets, Sloped external belts
1920:  No restriction (high or low) on caliber of turreted guns
and this one
1920:  No restriction (high or low) on caliber of turreted guns. Cruisers under 3000 tons may have composite hull strength > 0.75, Cruisers under 8000 tons may have composite hull strength >0.90

I figure once past these 1920 gatekeepers all restrictions on barrels / mount mix are past.

For example, I'd consider the RN's 5.25" MK 1 with it's semi stalk to be ..M&H initially ..but the Mk II with the long trunk and RPC..  Turret in the later incarnation?   

Actually I think the 8 barrel pom pom is kinda an interesting beast.
But I'm more interested in figuring out some plausible way to justify a gatling for close in defense.

The 1874 twin barrel Gardner gun was a cool hand cranked beastie,
and logically led to the GAST design, which historically could scale to the 15mm range.
The Soviets were the ones with GAST 23mms, which should be a logical endpoint for my light AA.
But... I have a fondness for the gatling look and mechanism, so want 5-barrel 23mm guns studding my ships firing all tracer.
But I need the nuisance value of light bombers to be high enough to justify the investment.

I'm also considering bringing back casements as a sort of Deck-edge mounting, like the dual 4.5" on some british Aircraft carriers,
allowing nice flat shots over the water at incoming Torpedo bombers for 90mms or 57mms. The 'secondary' guns would be at deck level, but have clear arcs of fire.

[TacCovert4]

Smiles

Looks at doing gatling 30mm.

[TacCovert4]

Kirk, I blame you

After a deep dive, a 37/55 AA Gatling is now on my radar.  In a single mount and hoist and a paired turret.  Probably a 4 or 5 barrel weapon.

[Kaiser Kirk]

You think it's feasible with 1920s-40s tech?
They do have trouble scaling things up, and that is a lot of mass and vibration,
paired with that short a barrel, I'd think MV would be an issue for actual engagement.

One advantage of ships though...having 'tons of ammo' is very possible.

[TacCovert4]

You think it's feasible with 1920s-40s tech?
They do have trouble scaling things up, and that is a lot of mass and vibration,
paired with that short a barrel, I'd think MV would be an issue for actual engagement.

One advantage of ships though...having 'tons of ammo' is very possible.

37/55 is a bit longer than the 37 Hotchkiss.   Given the Hotchkiss is late 1880s tech, I think you could realistically do a 37mm powered gatling with a useful rof.  I'm thinking a rof between 5 and 900 rpm per gun. 

I don't think you're going to get a gau-7 in 1930.  But there's not a whole lot technically in the way of it either.

[Jefgte]

...One advantage of ships though...having 'tons of ammo' is very possible.

Yeah, you can add AA lockers everywhere on the deck... like on HMS Hood.

[TacCovert4]

...One advantage of ships though...having 'tons of ammo' is very possible.

Yeah, you can add AA lockers everywhere on the deck... like on HMS Hood.

Precisely why mount AND hoist is probably a requirement.   Turret is best.  The ammo handling kit is going to be more important than the gun.

[TacCovert4]

Given that we were able to observe the Japanese 50mm gatlings, albeit manual old guns without the right shells, I'm starting an AA gatling next hy.

4 barrel hydraulic drive gatling.  Figure a 200 to 300 rotations per minute maximum,  giving 800 to 1200 rounds per minute.   While it's not really any faster than 4 separate single barrel weapons, the concept is to concentrate a hail of fire under the command of a single gunner that can work in an enclosed and powered mount with the benefit of all FC that he can get. 

The old 70mm AA gun is sort of useless Given that it's not in sufficient quantity on all but the newest ships,  and the slow rate of fire and old gun just don't stack against modern aircraft doing almost twice the speed of the early aircraft and zeppelins it was designed to shoot.

The 30mm is fine as light AA, but doesn't get any sort of help in controlled fires against the new concept of squadrons of torpedo planes.  So a 40mm/55 gun is what's in the works.  In a lore sense the gun has multiple uses.  The Navy is looking at these gatling installations for its larger combatants as an aircraft decimating system.   The army wants the single barrel 40mm as a field AA gun and to replace the old 40mm mountain gun for armor killing.  And the navy's light craft, MTBs and such,  need the 40mm as a primary weapon.

[Kaiser Kirk]

The question is... is that a weapon that is really doable?
Lots of weapons don't scale well to higher sizes.
Since the Gatling system had been widely used, why the search for higher
ROF went for multiple single guns linked rather than the gatling arrangement is suspicious.

In general volumes scale on a cube, so 30mm GAU -> 40mm, is a +136% increase
The larger the gatling, the greater the rotational weight, and the larger rounds impart more shock to the mounting, the faster you fire, the more kinetic energy you are absorbing.

The largest gatling actually developed was 37mm T250, -> 40mm is still a +26% increase.
Looking at the write up on the T250, it's not promising. Development started 1956, and reached prototype stage in 1960.. though apparently fireing trials did knock it out of battery sometimes.
and then never entered production, despite being considered for several difference applications over the years,
including being converted to 35mm for the DIVAD competition, which it did not succeed in, loosing out to the Sergeant York...
which as I recall failed trails because it's radar never worked right, leading to it locking onto a porta-potty exhaust fan and obliterating it.

https://www.guns.com/news/2018/12/18/vigilante-that-time-the-army-tried-to-make-a-37mm-gatling-gun-photos

Granted, Developing things that don't work are cool also - Foxy's hand cranked 50mm mounts are cool. They worked for what they were designed for - short bursts vs. MTBs. Also low MV and KE.

For my part, the 57mm AAs on my ships are really not a great compromise caliber. Dated to 1917 means - too low a ROF, but before auto-fuse setters and not a great burst radius,  But I will update the guns and probably wind up replacing them with quad 37s or 30s.
Sadly the GAST action seems to top out about 23mm, but that will be my light AA. From there I might go to 23->30mm Gatlings.

[TacCovert4]

The question is... is that a weapon that is really doable?
Lots of weapons don't scale well to higher sizes.
Since the Gatling system had been widely used, why the search for higher
ROF went for multiple single guns linked rather than the gatling arrangement is suspicious.

In general volumes scale on a cube, so 30mm GAU -> 40mm, is a +136% increase
The larger the gatling, the greater the rotational weight, and the larger rounds impart more shock to the mounting, the faster you fire, the more kinetic energy you are absorbing.

The largest gatling actually developed was 37mm T250, -> 40mm is still a +26% increase.
Looking at the write up on the T250, it's not promising. Development started 1956, and reached prototype stage in 1960.. though apparently fireing trials did knock it out of battery sometimes.
and then never entered production, despite being considered for several difference applications over the years,
including being converted to 35mm for the DIVAD competition, which it did not succeed in, loosing out to the Sergeant York...
which as I recall failed trails because it's radar never worked right, leading to it locking onto a porta-potty exhaust fan and obliterating it.

https://www.guns.com/news/2018/12/18/vigilante-that-time-the-army-tried-to-make-a-37mm-gatling-gun-photos

Granted, Developing things that don't work are cool also - Foxy's hand cranked 50mm mounts are cool. They worked for what they were designed for - short bursts vs. MTBs. Also low MV and KE.

For my part, the 57mm AAs on my ships are really not a great compromise caliber. Dated to 1917 means - too low a ROF, but before auto-fuse setters and not a great burst radius,  But I will update the guns and probably wind up replacing them with quad 37s or 30s.
Sadly the GAST action seems to top out about 23mm, but that will be my light AA. From there I might go to 23->30mm Gatlings.

While the Hotchkiss isn't precisely a Gatling, they have subtle differences, the US did deploy a 5 barrel 37mm rotary cannon....in the late 1800s.  I think that I'm staying within the realm of reasonable with the concept I've put forward.  And in some ways, no, this gun system is not as reliable as just having 4 completely separate guns on the same mount.  That's going to give you more reliability.  What I'm primarily aiming at, in the idiom of the Sultanate, is the concept of improving the actual control of the anti-aircraft fires by centralizing it down from widely dispersed single guns/barrels.  This has two purposes:  1)  Reduce footprint space, as more and more deck space is being taken over with AA weapons.  2)  Put the most firepower in the hands of well-controlled and highly trained personnel, to get the maximum effectiveness out of the guns.

The modern 'rotary autocannon' as we think about it today is an electric driven 5-7 barrel gun between 20-35mm in caliber, firing 4000-9000 rounds per minute.  Some of these systems are capable of being bolted on, so they'd fall into Springsharp as a 'deck mount'.  What I'm describing here is a 4 barrel, 40mm cannon, rotating at 1/6th to 1/2 the speed of the modern GAU-8, 100  and 300 rotations a minute for 400 or 1200 rounds per minute as opposed to the modern gatling doing 600 rotations for 4200 rounds.  It being mount and hoist means that it's getting ammunition fed up to where the crew can load the gun for bursts of fire of up to 200rds per hopper with 2 hoppers available to feed from (10 and 20 seconds of fire per hopper).  The M&H, and the fully enclosed (lightly armored) mount also means that you have quite a bit of mass and a solid tie-in with the ship itself, to help alleviate vibration issues you'd have on such a weapon.  But more importantly for what I'm trying to represent....you have 1200 rounds per minute centralized on a single line of bearing, under the control of a single gunner......the ability to reach out and work over an anticipated bomber or even torpedo bomber at that sweet spot where it hasn't deployed its weapon, and you have the maximum use of your fire control aids.  That's the concept that's driving this development.   

Overall, I would say that this will be a unique weapon system, if not as rugged as something like a quad bofors.  Basically, in universe, I'd see this system, in the hands of a trained gunner, as being able to rip planes out of the sky for short bursts of action, with a lot of required maintenance and a somewhat higher chance that the gun goes down mid-burst while they clear a jam (as opposed to the crew clearing a single jammed gun in a multi-pack of guns).

As for development, I'm building the gun out as a rotary, and I'll pay for the single-barrel mount separate, to account for the engineering costs of having just a single 40mm gun, even though they use a lot of the same components and ammunition.  The slow rate is to track onto target with the fast rate being the second stage of the trigger. 

I'm also anticipating teething issues, and am planning for a 5 hy development rather than 4hy.

No, it's not what we would personally know from experience as the 'best' option....25-30mm really is the best practical size for a high speed rotary cannon pushing 4000+RPM.  This will be a storyline thread for the Sultanate, of an experimental AA system that's going to 'change the game'.....only for it to take longer in development and then come into service with its high-speed setting very prone to jamming and still requiring tweaks.  Thus initially the 'revolutionary' weapon is merely a somewhat compact footprint of a 4 barrel AA gun that has little better than half the rate of fire of 4 of the single guns bolted together.  And over a period of time, the kinks with the 'second trigger' are worked out (mainly the jamming/feeding issues) and the gun reaches its potential a decade after it enters service.

[Kaiser Kirk]

[quote author=TacCovert4 link=topic=7962.msg102152#msg102152 date=1694399796
What I'm describing here is a 4 barrel, 40mm cannon, rotating at 1/6th to 1/2 the speed of the modern GAU-8, 100  and 300 rotations a minute for 400 or 1200 rounds per minute as opposed to the modern gatling doing 600 rotations for 4200 rounds.  It being mount and hoist means that it's getting ammunition fed up to where the crew can load the gun for bursts of fire of up to 200rds per hopper with 2 hoppers available to feed from (10 and 20 seconds of fire per hopper).  The M&H, and the fully enclosed (lightly armored) mount also means that you have quite a bit of mass and a solid tie-in with the ship itself, to help alleviate vibration issues you'd have on such a weapon.  But more importantly for what I'm trying to represent....you have 1200 rounds per minute centralized on a single line of bearing, under the control of a single gunner......the ability to reach out and work over an anticipated bomber or even torpedo bomber at that sweet spot where it hasn't deployed its weapon, and you have the maximum use of your fire control aids.  That's the concept that's driving this development.   

[/quote]

That goal sounds a great deal more practicable.  The burst rate is faster , but not tremendously so, and you're not looking for a lead hose with a ton of recoil energy the system has to take.
I like the 'wirblewind'  look to much to skip that for the bigger AA autocannon, but I'll either have a Gatling or a GAST for my lighter 23mm mounts. I'll probably go with the GAST as I've got a better lineage back to the Nordenfeldt, and somebody else is stealing the beautiful concept of Gatling AAGs...

[TacCovert4]

Pretty much.  The one perk of a rotary is that with each barrel firing at precisely the same point in space, that can be balanced on the mount so that the entire mount's structure is supporting against recoil.  While jamming will be a teething issue to work out, I won't have the vibration issues that guns like the 28mm or even some of the varieties of 40mm had due to offset recoil.