GraniteStater wrote:COMMENT
I am experienced, but not an expert on artillery and certainly no expert on ACW artillery. I do have a fair idea of the tech used then and can make some fair guesses. An informative point is that the shrapnel used, like Lee at Gettysburg, was fused by wick fuses - I mention Lee, becuase it turns out that his rounds at Gettysburg came from another factory than was used by the ANV up 'til then. QA/QC slightly different; the historian speculated that the ineffective barrage on the third day may have been due to just a fractional difference in fusing length for the wick fuses.
So when one is aware of this, wick fuses (lit by the propulsive charge) are hard to time for "air bursts", to give an example. They had one, two, three second fuses that could be divvied up into maybe quarter-second increments, at best, I would guess. Half second was probably all they expected. So timing anything like an air burst...does one see the problem in physics? With plunging fire? At a moving target perhaps a thousand yards distant or more? Yeah, you could rain shrapnel - if one gets it just right, 1/100, 1/1000, you get the drift.
Also, shredding sails, etc., ain't really all that effective - ask the French navy in their long experience with the Royal Navy. French doctrine was to to dismast - the British went for hull shots. The latter was more effective, as experience showed.
Hence my case of skepticism. Nothing ill meant.
Sea mortars - I'll have to click.
Dusting off my knowledge from my re-enacting days with Kerney's Frontier Regulars out of Fort Phil Kerney in Northern Wyoming...
I've serviced an 1841 Mountain Howitzer and a 12 pounder Howitzer. In this case the term refers to the gun design. Howitzers were constructed with tapered chambers so as to use approximately half the charge of the full gun. (A two pound powder charge in the case of a Napoleon is reduced to 1 pound, but the shot remains the same). The trajectory is less flat than a gun, so howitzers could be used to create plunging fire in siege operations, but it remained a direct fire weapon. In general, the federals got rid of the howitzers (except in the west) because they performed less well in battles than field guns, and mortars did the plunging work in sieges.
The standard federal fuse was the threaded Bormann fuse. A neat little contraption with a powder lined tube marked in increments to 5 and 1/4 seconds. Rounds would be fixed and stored in the limbers with the fuses attached. The gunner would estimate the range, and according to range tables inside the limber, the fuse would be "punched" for the appropriate time. The discharge of the cannon would light the fuse and the shell or spherical case (a shell filled with led balls, the explosive only served to break open the sphere not to accelerate the shrapnel balls) and the projectile explodes at the exact time desired. (If you find yourself low of canister, load case and punch 0 on the Bormann fuse)
In practice it didn't work so well. Ft. PK has a great display item of a recovered unexploded spherical case fired at Red Cloud's people, with the fuse clearly punched for 3 seconds. Bormanns also had a reputation of going off too soon, and Federal troops didn't enjoy their guns shooting over their heads.
The Confederates used Bormanns as well, but tin and other metal shortages limited their production capacity. So their guns tended to rely on "paper" fuses. Imagine a powder paste wrapped in a paper tube and marked with lines indicating burn time. Cut to the time needed and insert in the fuse plug. Relatively speaking, these fuses had big variability issues from batch to batch. (Which is why Bormann invented his fuse in the first place).
Assuming the fuse burns as intended, you still have to estimate the range correctly. This is another reason gunners liked to position for enfilade fire (beyond the art of skipping a ball down a file), you can fudge the range a bit and still hit something. My understanding is that most of Porter Alexander's guns were firing directly and they over shot the range. The troops on the ridge were fine but the wagon's and Mead's Headquarters just behind the ridge got knocked about. (And in fairness the per-invasion bombardment in Normandy did a pretty good job of hitting the fields behind the beach defenses.)
All mortars above 8 inches were classified as "Seacoast Mortars." The Dictator of Petersburg fame was a M 1861 13in Sea Coast mortar. So it would be totally accurate for the siege mortars modeled in the game to be used for coastal defense.
Now how would you hit a ship? You cheat and use range buoys. Before the enemy shows up, divide the harbor into per-assigned fire zones, measure the ranges, put out the range buoys, and practice. When the ships show up, point the gun, cut the fuze, and wait until he crosses the buoys. As far as fuses go, coastal mortars would be firing shells, so one simply uses the maximum fuse setting. The idea is for the shell to penetrate the wooden deck and explode inside. Even a solid shot plunging down would have enough kinetic energy through a deck and below the waterline.
Of course all this works best when the enemy fleet sticks around to slug it out and helpfully stays by your range buoyes. Rivers are a different story. Also remember that a naval force attacking coastal forts is likely going to be stationary. You think hitting a moving ship is hard, try hitting anything from a wildly maneuvering ship.
Oh and how do you turn your mortar?
These swivels would have been standard for coastal forts and mortar sloops/barges, but too heavy for field sieges. (Which is why Civil War photos of 13 in Sea Coast mortars have them fixed in one direction). Also, since the recoil of the mortar is mostly down, the gun doesn't really move after firing which helps with the next shot.
I haven't looked at the stats, but the "siege mortar" should have a long range, large hitting power, low rate of fire, and a long optimum range. Good for defending harbors, but poor in rivers.
