Gun Talk Thread

Started by Sachmle, September 20, 2011, 03:33:53 PM

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Tanthalas

oh on that point I agree compleatly, the "dreadnaughts" I simed for the period were just for laughs, Sort of What if projects never ment to be built but interesting to play with.
"He either fears his fate too much,
Or his desserts are small,
Who dares not put it to the touch,
To win or lose it all!"

James Graham, 5th Earl of Montrose
1612 to 1650
Royalist General during the English Civil War

Korpen

One way would be to include a cp on muzzle velocity depending on which for of powder is being used; say 450m/s for pure black powder, 600m/s for prismatic powder (and similar) and whatever when one gets smokeless powder. Perhaps only going into ME limits when one gets to smokeless powder?

Card-carrying member of the Battlecruiser Fan Club.

Logi

As I noted when writing my programs- it's easy to approximate the muzzle energy of various powders by changing the coefficient of the muzzle energy formula that P3D came up with:

Of course, I don't know what the actual names of propellants are (Cordite for example is just a period name, it's not a propellant)...

Black Powder (0.018) - pre-1865
Early Smokeless (0.032) - 1865-1880
TNT (0.038) - 1880-1910
Cordite (0.040) - 1910-1950

These variable coefficients form a soft cap on the muzzle velocity (restricting the amount of muzzle energy per caliber-diameter, but not how large the gun can be).

Korpen

Quote from: Logi on September 21, 2011, 07:41:53 AM
As I noted when writing my programs- it's easy to approximate the muzzle energy of various powders by changing the coefficient of the muzzle energy formula that P3D came up with:

Of course, I don't know what the actual names of propellants are (Cordite for example is just a period name, it's not a propellant)...

Black Powder (0.018) - pre-1865
Early Smokeless (0.032) - 1865-1880
TNT (0.038) - 1880-1910
Cordite (0.040) - 1910-1950

These variable coefficients form a soft cap on the muzzle velocity (restricting the amount of muzzle energy per caliber-diameter, but not how large the gun can be).
TNT???
Trinitrotoluen has never been used as a propellent charge (tto insensetive), and cordite was only used by quite few countries...
Card-carrying member of the Battlecruiser Fan Club.

Nobody

I think I also found a viable solution.
These really big guns all used black powder, and most were muzzle loaders <=30 calibers in length, right?

Then why not say every black powder or muzzle loading gun has a maximum length of 30 calibers and no limit on the bore diameter. Performance is limited by a chosen (rather low) value for the average pressure.
For breech loaders or guns using more modern propellants we make a table which list for each tech level how long a gun of certain caliber can be(similar to the one used in N3) and the gas pressure for this tech. And yes these limits require a bit physic & math knowledge or my program to be useful. And yes, it's likely and intended that muzzle loaders might be superior until the 1890s.

miketr

I split this off as its sorta off topic for the main thread.  I feel it does deserve to be talked about and can so here.

Michael

Tanthalas

Quote from: Nobody on September 21, 2011, 09:02:50 AM
I think I also found a viable solution.
These really big guns all used black powder, and most were muzzle loaders <=30 calibers in length, right?

Then why not say every black powder or muzzle loading gun has a maximum length of 30 calibers and no limit on the bore diameter. Performance is limited by a chosen (rather low) value for the average pressure.
For breech loaders or guns using more modern propellants we make a table which list for each tech level how long a gun of certain caliber can be(similar to the one used in N3) and the gas pressure for this tech. And yes these limits require a bit physic & math knowledge or my program to be useful. And yes, it's likely and intended that muzzle loaders might be superior until the 1890s.

less than 20 cals in length man, the 10 and 11 inch ones I have been playing around with were only 13.2 cal in the 1860s/1870s
"He either fears his fate too much,
Or his desserts are small,
Who dares not put it to the touch,
To win or lose it all!"

James Graham, 5th Earl of Montrose
1612 to 1650
Royalist General during the English Civil War

Nobody

Quote from: Tanthalas on September 21, 2011, 01:48:15 PM
Quote from: Nobody on September 21, 2011, 09:02:50 AM
I think I also found a viable solution.
These really big guns all used black powder, and most were muzzle loaders <=30 calibers in length, right?

Then why not say every black powder or muzzle loading gun has a maximum length of 30 calibers and no limit on the bore diameter. Performance is limited by a chosen (rather low) value for the average pressure.
For breech loaders or guns using more modern propellants we make a table which list for each tech level how long a gun of certain caliber can be(similar to the one used in N3) and the gas pressure for this tech. And yes these limits require a bit physic & math knowledge or my program to be useful. And yes, it's likely and intended that muzzle loaders might be superior until the 1890s.

less than 20 cals in length man, the 10 and 11 inch ones I have been playing around with were only 13.2 cal in the 1860s/1870s
What about the Italia class's 17"/26 (or was it 28)?

Logi

Korpen...
Quote from: Logi on September 21, 2011, 07:41:53 AMOf course, I don't know what the actual names of propellants are (Cordite for example is just a period name, it's not a propellant)...
That's just a name of the period that the explosives were used. They're just placeholder names for actual propellants of the period- simply because I don't know the propellant names!

Quote from: Nobody on September 21, 2011, 09:28:17 AM"Energy Density", I think that's the value Logi mentioned increasing over time (but in metric units). The figure on the right shows that it is actually non-linear.
Nobody - The energy constant I mention is derived by the equation P3D gave:

Muzzle Energy = coefficient * Diameter^3 * Caliber

Your energy density graphs are on the right track, but lack the crucial diameter information- the diameter of the gun. Your current graph displays energy density in only one-dimension, hardly fit to be called density (cubing the same value doesn't make it density unless your gun happens to be a cube whose sides the caliber length long).

If you could post a new graph with that in the y-axis, that would be great- considering I don't have the specific data values you have on hand. It should make the graph on the left show jumps over specific periods of time.

I say should because most of my testing has been backwards deriving the muzzle energy of the gun from it's muzzle velocity etc. to determine the approximate coefficient.

Quote from: Nobody on September 21, 2011, 09:02:50 AMAnd yes, it's likely and intended that muzzle loaders might be superior until the 1890s.
I don't think this would be desirable- considering that by 1880 the de Bange system made the muzzle velocities of the two gun types virtually equivalent.

Ofc, that's post-1880, not pre-1880...

Kaiser Kirk

Quote from: Carthaginian on September 20, 2011, 10:55:27 PM
Logi and I agree, actually.
This is really the best argument there is against building a large, dreadnought-type ship ATM.
IT JUST WON'T WORK.

Sam, we're just going to have to accept some risk if we want this freedom.
In order to have freedom, there has to be freedom to abuse the freedom.

One of the things I had thought might be "fun" in this period would be a steam ram with a truely massive gun fixed along the centerline- a "wave motion gun" if you would.  Closest in application would be the USN's "dynamite" guns.  Transitioning from the hard cap on ME to a caliber-cap allows folks to explore wierd options and establish why they might fail. That should be one of the joys of a simulation. - just my 2 cents.
Did they beat the drum slowly,
Did they play the fife lowly,
Did they sound the death march, as they lowered you down,
Did the band play the last post and chorus,
Did the pipes play the flowers of the forest