kbluck

29 Aug 03, 20:53

I've long had a nagging feeling that mortars were being shortchanged in ATF. The relative impotence of mortars in the game just doesn't jibe with my historical reading. So, I did a little research, did a little math, and came up with some interesting results and what I think is a justification to improve the kill effectiveness of mortars. Comments welcome.

It seems to me that the best way to evaluate the comparative effect of different artillery rounds is to compare their weights rather than their caliber. I believe this would most accurately account for their relative explosive power and fragmentation potential without getting into a lot of complicated physics.

If you accept that, then lets look at the rounds in question. A M107 155mm HE round weighs in at around 95lbs, while a M933 120mm HE bomb tips the scales at around 30lbs, about 1/3 the total weight. So, you would expect the mortar to be about 1/3 as effective.

But wait! We're not talking about equal areas of effect here! If we're assuming that the concussion and fragmentation is being distributed evenly through the area of effect (a game abstraction) then we find that the 120mm, with its 20m radius, is "attacking" a total area of only 1/6 that of the 50m radius covered by the 155mm. (Pi*r^2, if you've forgotten elementary geometry.) So, it seems to me that if you keep the radius at 20m, the 120mm round should be roughly twice as effective as the 155mm over that reduced radius!

If we expand the mortar's radius to 30m, which would have an area roughly 1/3 that of 50m, we get a pleasing concordance: the 120's "effect per square foot" runs about 85% of the 155. Given the "declining return" per pound for large charges vs. small ones, and the denser fragmentation pattern typically generated by cast iron mortar bombs vs. machined steel artillery shells, I think it is reasonable to "upgrade" the mortar a few percent to 95% or so over the 30m radius.

So, I think there is a compelling case here that mortars have been seriously shortchanged in database1. Am I deluded?

--- Kevin

It seems to me that the best way to evaluate the comparative effect of different artillery rounds is to compare their weights rather than their caliber. I believe this would most accurately account for their relative explosive power and fragmentation potential without getting into a lot of complicated physics.

If you accept that, then lets look at the rounds in question. A M107 155mm HE round weighs in at around 95lbs, while a M933 120mm HE bomb tips the scales at around 30lbs, about 1/3 the total weight. So, you would expect the mortar to be about 1/3 as effective.

But wait! We're not talking about equal areas of effect here! If we're assuming that the concussion and fragmentation is being distributed evenly through the area of effect (a game abstraction) then we find that the 120mm, with its 20m radius, is "attacking" a total area of only 1/6 that of the 50m radius covered by the 155mm. (Pi*r^2, if you've forgotten elementary geometry.) So, it seems to me that if you keep the radius at 20m, the 120mm round should be roughly twice as effective as the 155mm over that reduced radius!

If we expand the mortar's radius to 30m, which would have an area roughly 1/3 that of 50m, we get a pleasing concordance: the 120's "effect per square foot" runs about 85% of the 155. Given the "declining return" per pound for large charges vs. small ones, and the denser fragmentation pattern typically generated by cast iron mortar bombs vs. machined steel artillery shells, I think it is reasonable to "upgrade" the mortar a few percent to 95% or so over the 30m radius.

So, I think there is a compelling case here that mortars have been seriously shortchanged in database1. Am I deluded?

--- Kevin