I don’t understand how they can accurately aim artillery. When they fire the whole machine moves a great deal and it would seem any calibration of its position would be lost.
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The word “Computer” originated from the Army MOS with the same name whose job it was to literally computer firing solutions.
My father was an artillery engineer at Fort Sill , Oklahoma in WWII. His unit was responsible for calibrating the heavy artillery pieces that came from the factories. As he described it, they would fire dummy rounds into a precisely mapped range, each with it’s own unique registration number marked on it. They’d document things like size of the charge, elevation, temperature, wind speed and direction, etc before firing each one. Once the firing stopped, a group of enlisted men were sent down range to collect each shell, noting the exact location where each was found. Once all the data was collected, they’d create slide rules for each artillery piece. As others have noted, though, that was just to get the first rounds close in actual combat. Forward observers we’re still needed to fine tune the final barrage.
I remember as a kid, we had a few of those slide rules laying around, and one of the dummy rounds for a very large door stop in our basement.
It’s all trigonometry, so it’s hard to simplify. I was US Army field artillery from 01-07. We had the M109A6, so things could be easy. We also had Captain America as a battery commander, so we trained manual A LOT (which probably helped us win the Henry Knox award).
You essentially set up several references. One of the most important references is the collimator. As you rotate (traverse) the canon, your aming site can tell you to the mil (6400 mils in a circle vs 360 degrees). As a backup to the collimator, a set of aiming poles are ran out that can act as the collimator in a similar, but less accurate manner.
The collimator is set up off an aming circle, which again is another reference. There’s also a safety circle, which is a second aming circle to make sure the numbers aren’t too far off.
Everything above needs to be done in 2 minutes.
After all this setup, your gun is “laid”. Fire direction control does other stuff that I didn’t get to see. But once everyone is set up, a forward observer sends you a **FIRE MISSION** and the fun begins. With a **FIRE MISSION** you get a shell/fuse combination, a charge (bags in my day but they’ve updated those), a deflection (left or right), and an elevation (up or down).
If the Army could have promised me to shoot the howitzer at least once a week, I would have never left.
I’m not sure if its been mentioned, but wartime mathematicians were faced with this problem. You have a ‘boundary value problem’ i.e the bad guys are at the boundary (you dont want to shoot passed them do you?). But you only have information regarding your ‘initial conditions’ i.e you know what angle your mortar is facing. So how do we hit them?
The [Shooting Method](https://en.m.wikipedia.org/wiki/Shooting_method) is the answer to this. Its a way to numerically reduce the boundary value problem into an initial condition problem.
Warning: link contains differential equations
Artillery are aimed *extremely* precisely. You know 360 degrees in a circle. The military uses mils with artillery, of which there are 6,400 in a circle. I know we have fancy electronics these days such as GPS and high-precision gyrocompasses, but I’ll go through the old way to perfectly aim an emplacement.
For very accurate long-range shots, surveyors put down marks on the ground at very precise locations. The artillery is emplaced. Towed artillery will be dug in. Mobile artillery has lockouts on the suspension to make it a stable platform (think of putting a solid steel rod across your shocks and springs to the axle so there is no movement). Very precise survey equipment is used, at mil increments, to point artillery based on those marks. This is related to the stuff you see surveyors using on the roads, extremely accurate, extremely expensive.
Then the weight of shell, atmospheric conditions, wind, etc., are all crunched to determine the elevation and azimuth, and sometimes amount of powder (larger artillery), needed to hit a target from your point. The forward observer, the person looking at the target, also has responsibility for properly designating the target’s location (they can get that wrong).
Then you aim the artillery and shoot. A forward observer spots where it hits, and this is called the spotting round. Sometimes you need multiple spotting rounds to “walk” onto the target. Once you’re dialed in on the target, well, you’ve probably heard the term “fire for effect” in the movies. Whole artillery batteries will just hammer the target over and over until someone decides it’s enough.
They can avoiding giving warning to the enemy with a spotting round. Say your target is at 1000 mils at 10 km. They can shoot a spotting round in the direction of 1400 mils at 10 km so it doesn’t spook the target. If it lands where they expect, then move back to 1000 mils and fire for effect.
You seen those movies where snipers are doing their calibrations/calculations for their shot? It’s like a slightly more ball-parked version of that (because: explosion)
Something id also like to add here: nowadays we use gps guided ammunition.
The shells have a guiding package and little wings. The guidance package has a lot of sensors and a computer that calculates the trajectory and the necessary adjustments.
To demonstrate its effectiveness: before, a 150mm would hit in the general area of the target. You target a house in a city? Might aswell hit the house next to if, or any other one in a 100m radius (rough estimate). Nowadays a guided shell can precisely hit one house in a city
I havent seen this in the upper comments so let me try and shed some light. I used to shoot, load, operate radio, prepare ammo (13B, whats the sound of artillery!? BOOM BOOM!) howitzers in the US Army for my credentials. Without giving away the boat here it is as simple as i can. When you ‘lay’ a howitzer you essentially use a fixed/known point on a map by putting what is more or less a survey stick in the ground. Its got a bunch of ‘doohickeys’ to help you with that. From that point you sight into that fixed point from the howitzer, and with the distance and angle from the howitzer to the known point the super smart guys in a truck behind all the gunners triangulate your position on a map.
Your howitzer is now ‘laid’ at this point. You now shove a smaller fixed targeting device in front of your howitzers sights. This device has essentially a targeting reticle in it. Your initial laid position will be 0’0′ degrees on the reticle.
With that out the way heres my attempt at a explain like im five. Smart guys in a truck in the back know where the big boomy gun is right? So they use Big Maths (trignomotery) that you will only ever use if you are an engineer to tell you where to aim and how high to point the barrel of the big boomy gun. After you fire you use another sight that was put out before you fired to get back to the same relative position as before.
I realize im not cut out to be a elementary school teacher. To brag slightly and to express the effectivemess of this. During a training exercise i once was given coordinates to fire on a truck, not moving, which was about 7 km away. Four rounds fired and four rounds steel on target. Shit seems like magic but it works.
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