Eli5: How are artillery aimed?

Question

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.

In: 723

Answer 1

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.