Firing a Mortar for Dummies (OurPastimes Week 1)

mortar fire

HowStuffWorks week was so much fun that the staff voted to feature another website for a week. In reality, what brought that on was noticing just how doofus some of the posts at Leaf Group's OurPastimes.com niche are, not to mention how easy it is to follow a trail of links from one candidate to another. We already had a pile of candidates in the files, though, so we'll start with one from returning DotD Brittany Prock: her take on "How to Aim a Mortar,"

The weird notion that aiming a mortar is a "pastime" notwithstanding, we polled the staff and found that none had ever fired a mortar, which puts us in the same boat as the diet and travel blogger who wrote the article. We do, however, have staffers who have at least some knowledge of ballistics, the physical science that appears to escape Prock.

We say that because, as Prock notes in her introduction, we know that

"...[a mortar's] aiming system is different from most as it is designed to be fired at targets... that the person firing the weapon may not actually be able to see."

We won't harp on Brittany's grammar, 'cause it's immaterial here. She's correct, though, in saying that mortars are typically fired at unseen targets. That means – to us, at least – that the mortar must be positioned so that the barrel points at the correct azimuth and is raised to an angle (elevation) that will land the projectile at the necessary range from the firing position. This is basic physics! Firing at random is so... random.

Prock, however, did not seem to understand the two elements of aiming. She went through a long, involved process of describing how to set up the mortar and set out aiming stakes (from a reference on black-powder cannons, FWIW), after which her instructions frankly went batshit crazy. Brittany says to, "Determine the azimuth of fire by finding the direction between the two points. Look up the elevation settings for that azimuth in the mortar elevation guide, which comes with all mortars." We guess that's an acceptable definition of "azimuth," although the mortar manual she claimed to have used is a little more detailed:

"...direction is a horizontal angle measured from a fixed reference. The indirect fire team normally measures direction in mils clockwise from grid north, which is the direction of the north-south grid lines on a tactical map..."

Things get worse from that point: the second quantity in the targeting ballistics is range, which in the case of a mortar translates to the angle of elevation of the barrel. According to Prock, however, the person aiming a mortar must,

"Look up the elevation settings for that azimuth in the mortar elevation guide, which comes with all mortars."

Say what? We hate to tell you, Brittany, but the elevation settings are for the range, not the azimuth! And that doesn't even take into account several other factors like charge weight, wind velocity, difference in elevation between the mortar position and the target, temperature, ballistic drift...
Nope Brittany had no earthly idea what she was talking about, which is all we needed to know to give her another Dumbass of the Day award for her mantel.

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