Naval Weaponry

[Kaiser Kirk]

Order coming right up, do the Inca want the the 3 barrel one available now, or do they want to wait for the improved 5 barrel version?

The design can easily be modified for more shells if the Inca are interested in that particular TB.

A) It fine to use historical weapons like the Hotchkiss rotary cannon.
Modeling it as a triple or quintuple mount is ok.
B) Rounding :
                     -It is fine to round those to the nearest 5mm. so if it's 37mm and you use 35mm..or 40.. go ahead.
                     -The guns on the TB are 50.8... which happens to be the nearest English measurement, that's fine.
D) Maddox mentions 58mm, that is not ok under either of the two rounding measures, Historical 6pdr/40 Hotchkiss did exist, but were single-barrel and 40 not 50 calibers.
E) Once "active" You need to have a naval artillery list. New weapons not already mounted in the pre-build fleet must be purchased, or researched.

OOC
That Hotchkiss is a rather mechanicaly simple. I could build one in my own workshop. And with some help, I can build a modern electricaly cranked and fired caseless version of it.
(could start a Kickstarter on that.  Join the club Desertfox?)

Well the Japanese 4-pounder is 2" (50.8mm) not 57mm. That said, I haven't started researching it, but a bigger 57mm shell would be nice to have. Kirk, would a rotary that big be doable? The 50.8mm ones should work just fine. Now the real question... can it be scaled up to 3" (75mm)?

Working on getting that list up, got distracted by the war. I thought I had a 5 barrel one in one of my ships but went back and checked and I do not... So yeah the 5 barrel one will have to be researched, the Incas saw the prototype version.

OOC Don't tempt me...

Answers

Pregame, the options were to use the gun research rules to make weapons.
We agreed using historical weapons was acceptable.

As part of the rule updates, I added a clarifications that the breakpoints in the gun research table can be rounded to a 5mm break.
The goal was to make it so folks can field weapons at even intervals if they want.

Here I was clarifying that rounding should apply to historical weapons as well.
However, using historical weapons means...they have to have been historical weapons in general use.

The idea of scaling up, that the gun is simple, has merit.
BUT - We generally stick to the historical weapons.

For sub-75mm weapons, I may allow some "progression" for "storyline" purposes.
These would not be things like an electrified gatling gun, and no the fact they made one in the 1880s does not count.
These would be "mistakes" or "for "storyline" - they might even be "adequate", but not a means of making a war-winning weapon.

An example is the Gardner gun Parthian ships have. They worked, they were reliable but heavy, so they are decent Naval guns,
but they really aren't "better" than a Colt MG. They will lead to the GAST gun, because I like Twin Barrels....but the GAST
wasn't that much better than 2 seperate MGs.

As for the 5-barrel 57mm Hotchkiss..

One would assume that Hotchkiss had the very same idea of scaling up.
One would assume that Hotchkiss tried it.
Yet the 57mm they produced for service was a single-barrel.

Why?
There are a number of options
A) SS puts the weight of a single barrel at .8t, but a 5 barrel at 3.6t, for which you could have 4 regular 57mm guns, or 2x75mm guns. Considering Navweaps puts the 47mm 5-barrel ROF at 30  and the 57mm 1barrel  ROF at 20... and a 75mm ROF at 15... this is not an efficient use of tonnage.  When one looks at the Hotchkiss guns, there was a high short term ROF which fell off, in this case 60 design, 30 practical, with single barrels being 20-25.

B) For land use, in WWII the Infantry did not want to give up the 50-57mm guns, as they could still be manhandled. A 5x57mm would be unweildy and require assistance from animal or machine.

C) For naval use, a weapon with a MV in the 550-650m/s  range, and a 6pdr shell is just not that useful by 1912. Increasing the MV would increase the stresses and increase the weight of the gun and mount. With the current MV it needs to be at 20degrees just to get a round over 6000m, it's reduced to lobbing shots at a swiftly moving TB.... not useful.

D) These were reloaded by clips, loading a 10 round clip of 37mm took about 18lbs, but each 57mm round weighs 9.5lbs, so the clips would get shorter and the loading times longer.

E) These were handcranked and pointed guns. Increasing the weight means it's harder to train, and takes a great deal more power to crank to get the barrels to rotate. Which likely reduces the ROF.

F) All and all, it seems reasonable one COULD upscale the Hotchkiss design, but there are many reasons why it would likely not produce a workable weapon. Adding  that to the historical fact they don't seem to have bothered to make a 5 barrel 57mm, it seems reasonable to conclude that it's not an effective weapon design at that scale.

...so sure, go ahead.... but be warned it may not be the best result.

[maddox]

IC
If a naval engineer can explain this all to Sapa Inca, it would be clear it isn't the war-winning invention he sees in it.

Unfortunatly, the Japanese salesmen did do a good job selling it.

OOC,
Yes, I know. But if I wanted the best ships for the job, I wouldn't put on the cap on the big ones on 10Ktons, and I would accept destroyers in the fleet-mix.

[snip]

For sub-75mm weapons, I may allow some "progression" for "storyline" purposes.

To really hyper-fixate on something, I would like to see something like this codified in the rules. Since its going to encompass a majority of Anti-Aircraft weapons, its kinda major.

Personally, I would propose allowing declaration of any weapon under say 60mm (lets these 57mm rotary cannon in, but cuts of small anti-shipping weapons in the 75mm range), but require development of anything other than a single mount for them. Discretion could then come into play with what constitutes a single mount. [e.g. In 1917H1 Rome declares to have created a 14.5mm heavy machine gun for naval use. Roman ships can mount these in single mounts immediately, but must research any twin/tripple/octuple mounts as they would any other weapon]

[Kaiser Kirk]

I was only planning on allowing "declaring" for weapons "developed" as part of the prebuild setup process.

Once in regular play, you are expected to develop weapons according to the tech.
That should be Machineguns on up.

The question here is about developing a "quintuple mount" weapon- which would not be allowed under the tech.
However the practical effect is 1 autocannon, and it is an logical expansion of a historic weapon which is likely either useless, or equal to similar weapons.
If someone wants to burn research on that..ok. ....but there's reasons people didn't choose to field that weapon.

[Desertfox]

To be fair, the weapon Japan has been offering is the 2"/50.8mm/4-pounder, not the bigger 57mm/6-pounder. I knew it was already pushing practical limits, which is why the Japanese use a 3-barrel and not a 5-barrel version (also I was scaling up from the 37mm version, not realizing a 47mm version existed...).

That said, Japan did note that mechanically there is no reason why a 57mm version can't be developed. Is it practical? That is a different question, but mechanically it can be done. Kirk, I think you hit on all the issues. Is a 5-barrel 57mm gatling better than 4 single 57mm or 2 single 75mm guns? I would say that in most cases its not, especially if it needs a 100mm gun style mount. But are there cases where it would be better? Perhaps. The main advantage large caliber gatlings have over single-barrel guns is not necessarily max RoF but max sustained RoF, since they will not overheat. The single barrel 57mm could hit 20 rpm but might only be able to sustain it for a sort period of time, while the gatling is only slightly better at 30 rpm but can sustain it as long as its supplied with ammo.

So for a secondary for ship-to-ship combat in the high seas, the drawbacks very likely outweigh the advantages, but as the main weapon on a river gunboat that requires short-range sustained suppressive fire? maybe that is its niche.

[Kaiser Kirk]

I would say the only advantage is it looks way cooler,
and that it takes less space - which sometimes matters.

If 1 5-barrel has an ROF of.. 30 (and that may be generous since some poor guy is handcranking 3 tons,and then you have the feed issue)
and you could otherwise have 4 guns firing 20rpm.. or 2 firing 15rpm, the weight of fire stays with separate guns.

as for sustained ROF, I believe in  WWI the French would use their 75s at 15rpm for sustained bombardments, as they lacked many larger guns.

[Desertfox]

Maybe in a riverboat you want all-around protection which is easier to do with less guns, and the weight is not as much of an issue since you have an armored gunhouse. Perhaps also require "mount and hoist" to account for the extra weight of the machinery? Maybe also going with say 3-barrels, would keep most of the advantages while mitigating some of the disadvantages?

[Kaiser Kirk]

Yes, a limited space like that is what I was referring to.
The Dragonfly III incorporating the 5x Barrel concept (Japanese guns bought by the Inca and installed on Parthain GB) in casement mounts is an example. There's not room for 8 guns on the broadside, and 2 casement mounts at the corners of the casement give better angles than 8 squeezed together broadside.