"Artillery and heights?" Topic

A case of laziness as in "someone else might have already done the research". I have period books which, dug inside, have the answers but…

1 Did smoothbore (and later rifled) artillery gain any range firing from heights? (I was tempted to say no even less as no bounce)

2 How to model the inability to shoot down significantly? though of a % of the slope as they give on roads; easy somewhat to calculate for ex., your 2 levels are 30m high and the target, maybe 500m far, so the tentative shooting is 6% down. Obviously best to define broadly when explaining the terrain. What do the remaining guys with good knowledge here say about it?

I don't believe they gained distance from heights and the challenge of depressing the muzzles of the guns would be limiting near the base of the heights. But their opposition would have limited ability to return fire on them, which would be of some help. All IMHO, of course.

Not helping much but game I have has a few batteries on a hill and was ponder this question. To me obviously hight adds to range, no idea of how much a cannon could be depressed but am limiting close range on my game.

Very mild heights seem to have been best, sending the solid shot bouncing down a gentle slope. As they got higher and steeper, the improvement in visibility was counterbalanced by the reduction in bounce. I've never seen it expressed in "real life" numbers. In CLS, we gave a modest (1") range improvement for each of the first three contours, but started "plunging fire" at the fourth contour. For canister, of course, higher was just better. Same with shell.

The simple answer is yes, if a projectile still has some forward momentum the extra height will increase the range. A howitzer firing at maximum range where the projectile is falling vertically when hitting the ground would not be any different.
Conversely, a projectile firing up hill will have a reduced range.

At Lobostitz Frederick sited his batteries on a hill, I believe, and they had some effect. Maybe one to look at.

On the field that plunging thing at the end might be useful (Russian gun/howitzer shells) for getting into defilades and trenches.

The extra-range from a little extra height might be more useful for guns mounted on castle walls.

I seem to have it in my head that besiegers would camp from 1.5 to 3 miles from castle walls – assumably to avoid harassing fire from the castle. (Possibly learned in Cyprus during the 1570 Turkish sieges of Nicosia/Lefkosa and Famagusta/Gazimagusa)

link

Simple answer is yes. How much more? The math gets complicated. Maybe there is a former artillery officer who can chime in with a rule of thumb.

Yes, if only we had a former artillery officer around steeped in the knowledge of period pieces, hmmm.

I think the technical, geometric answer is, yes, height does add to range. But: Did anybody engage at extreme range in the first place? (This is an old wargame argument based on the fact that ammunition is a limited resource and the farther away a target is the greater chance of a miss, and people almost never fired at maximum range the way wargamers do--me included!).

Given a few minutes, you could dig a hole under the trail of the gun, so it could fire at a higher angle, presumably the opposite could be done if you needed to fire down.

Firing down, I think a more common problem is that people who should have known better placed their guns on the physical crest of the hill, rather than on the military crest (usually a bit further forward). This created dead ground in front of the guns, where enemy couldn't be seen or shot at. Examples include the Confederate defenses on Missionary Ridge (1863) and the Spanish earthworks south of Santiago de Cuba in 1898.

Grelber

Forgot to look at Kriegspiel 1824….
"ARTILLERY WITH BAD EFFECT 1) CANISTER SHOT. If the ground is undulating or slopes more than 10° up or down in front of the target, or if there are swamps, ditches, or other obstacles for 150 paces in front of it.

2) SOLID SHOT. When the ground slopes more than 15° up or down, or there are terrain obstacles for a quarter or more of the distance in front of the target.

3) RANDOM SHOT. If the ground is undulating, or slopes for more than 10° up or down in front of the target (as for canister shot), or if there are obstacles of ground within 600 paces of the target. "

Nothing about greater range from up. Obviously better Los.

Indeed Jcfrog! – You never hear of troops masking their own guns when they are uphill.
I think it would be better spotting – especially with the amount of smoke produced in Horse and Musket battles.

Yes.

Physics 101……

An excerpt from an essay on ACW artillery I wrote a long time ago -

"The nature of the terrain in the principal theaters of the Civil War offered very few locales with anything approaching long sight lines. Rolling terrain and substantial forest cover often restricted vision to less than a thousand yards. A site upon a gentle elevation overlooking the surrounding area was quite desirable, as it offered a much better view over the irregular terrain. A position just behind the crest of such an elevation provided good protection from counter-battery fire as well. An elevation too high and steep was not desirable, as it would reduce the effectiveness of the battery's fire and prevent the guns from covering their immediate battery fronts due to insufficient depression of the gun carriages. In the wilder and less cultivated regions of the west (Shiloh, Chickamauga) and Virginia (the Wilderness), life for the artilleryman was much more difficult, as visibility might be anything from two hundred yards down to ten yards within such vast forested expanses. Good battery positions were not always easy to find."

FWIW.

B

As a way to simply simulate the advantage of a height position, my home rules include a negative for firing at targets up-slope. The mechanism settled upon was to simply use the next longer range.
Short range uses medium range, medium uses long and long suffers a -1 modifier to the d6.

1. The height does not add to the range of a cannon. The powder and shot weight determines that. Height allows a cannon to fire at a longer range because there are fewer obstacles like trees and slope to interfere with the flight of the shot.

2. This is more complicated. You do not need to use percentages since that would slow the game. Simple die rolls on the acquisition of a reverse slope target is quicker. A reverse slope target that blocks LOS of guns on the same level would allow some opportunity to a battery on a level one hill but not automatic. A battery on a level two hill, two levels above the reverse slope target would be easy to spot.

Firing at targets at the base of your hill is difficult. If can target them, then they can target you. Back in the 1980s we used a simple measurement. You measure from the front of the firing battery and then the same distance from the edge is the available range. So if you are set up four inches from the edge, then there is a dead zone of four inches down the slope.

Higer ground did extend the range of ball artillery fire as well as provide better visibility for the most part.

However, I am not sure about firing down hill. I doubt that it was any advantage, but if there was some limit to how far the guns could be deflected down, I haven't read about it. It might be true, a limit on downward aiming, but then you have to explain things like the British artillery at Bussaco. Those slopes were STEEP, and yet the British didn't seem to be hampered in hitting the French downhill.

ACW artillerist manuals (Gibson, for example) cautioned that siting a gun on a steep forward slope would cause undue stress to be placed upon the gun carriage when it was fired. A 4 degree slope was considered the practicable limit.

That was one of the factors the often made selection of battery sites such a challenge. Field artillery could not just be dropped anywhere and be expected to deliver best effect.

B

B: Yeah, even uneven ground, where one wheel was higher than the other could cause problems.

Knowing that, including what ACW manuals say about firing downslope, such actions as those at Bussaco remain unexplained. As I said, the slopes there were really steep.

He did do the oar jumping in Viking, local papers had a really good write up about it with pictures.

Another s/ware screw-up. My response to McLaddie re artillery was ambushed by the above Viking oar jumper.

RATS!

B

McLaddie,
The case you refer to = trunnion tilt, which will cause the flight of the projectile to deviate toward the downward cant of the gun more or less consistent with th amount of elevation put on the gun. Big problem in naval gunnery as well.

It's always difficult IMO to make judgments re slopes without access to an accurate small-scale (and ideally contemporary) topo map.

B

I'm going to toss this one in – just for laughs:

The British gun-carriage design allowed greater depression of the barrel without blowing the cap-squares off.

As compared to Franco-pact equipment.