Explosive effectiveness

[Milano]

I have been working on doubling weapon damages and such stuff and have run into a question.

How much damage in real life does shrapnel do?

Doesn't it depend upon the projectile size also? (I have thought of having different damage values based on the weapon. Hand grenades, 60mm mortars in one. Then anything up to 125mm. Then the big boys bigger than that.)


Studies have said that artillery are huge casualty producers on the battle fields but in game terms, excluding concossion effects, it doesn't do more than a hand grenade. Any thoughts would be appreciated.

[simonmark6]

I think that the differences in destructiveness are modeled by the blast range. The larger shells are more deadly because they have a larger blast range and thus have more chance of hitting more people. For instance, a grenade's bast has a chance of harming anyone in a radius of about 30m whilst a 122mm shell's danger zone covers over twice that much.

[HorseSoldier]

In terms of trauma, shrapnel will be like any projectile, with power determined by mass and velocity -- of the fragments, not the shell, grenade or whatever launching it. I'd think you have much greater potential for heavier and more energetic projectiles coming from large artillery and bombs and the like -- but still a chance of small and weak. Maybe if using the 1st edition rules for damage use the standard d6 x d6 roll, but any time a 6 comes up reroll with a d10. Gives a potential up to 100 points of damage which would effectively model the occasional fragment powerful enough to just rip someone apart. Or maybe have a primary and secondary drag zone, with d10xd10 in the primary and d6 x d6 in the secondary.

[Legbreaker]

How long is a piece of string?
The larger/faster shrapnel is moving, the higher the likelyhood it will do serious injury/damage. The shape and even how jagged it is will all likely have some influence on the end result.
All in all though it's a bit of a crap shoot. A weapon designer can prefragment the detonating device to (hopefully) evenly spread shrapnel of approximately equal size and (again hopefully) with predictable results, but there will always be an element of randomness.

Throw improvised charges into the mix, not one which is the same as another, and the situation gets even less predictable.

Without carrying out some fairly complex calculations for each and every blast, it's doubtful a truely accurate game mechanic could be developed. Take your best guess based on what you know and what you've been able to research - it's not like the players will know the difference when they're either catching a grenade in their teeth or putting up the bullet proof umbrella during a 203mm HE hailstorm.

[HorseSoldier]

The emphasis has been on getting more consistent and relatively small fragments from HE weapons intended to fragmentation effects, the better to ensure hits on personnel or other targets in a kill zone. I don't recall the exact numbers, but read years ago about some experimental tests on fragmentation, where there was a higher probability of hits from fragments from mortar bombs but artillery (I think 105mm, 122mm, and 155mm were all listed) was much less consistent in fragment dispersion . . . but there tended to be some very notable "sucks to be you" fragments coming off those rounds, made up of large enough chunks of the shell a target might be killed or incapacitated even if the frag hit body armor or helmets. Getting howitzer projectiles downrange at the pressures and velocities they run at meant the shells had to be sufficiently heavy that they were not optimized for fragmentation, whereas lower pressure mortars were much better in that respect.

[Legbreaker]

I wonder if angle of impact has anything to do with it too? A mortar round is fired on a high arc, so would usually impact in a more vertical position allowing fragments to be relatively evenly spread sideways, while an artillery shell is usually fired at a flatter trajectory. If it were optimised to spread sideways from the round, a large proportion of the fragments would be directed downwards into the ground while more would go up into the air.
That's overly simplified, but I hope you can understand the general idea.

All in all though, a 105mm round is going to be about as healthy for you as catching a 4.2".