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Frag radius for BLU 26, 36, 59, 63,86

weberoed

Well-Known Member
Ordnance approved
Does anyone know the lethal fragmentation radius (90% kill) for the listed submunitions? I have 6 .7m for the 26 and 16m for the 63, but I can not confirm those ranges.

Thanks
 
Hi
(sorry for my English)

Well, I can try to calculate this, according to russian website http://saper.etel.ru/mines-2/razlet-osk.html

BLU-26 contain 600 embedded steel fragments.

According to the website mentioned above, the average human body area in frontal projection is 1,08 m2 (square meter). If you need 90% probability of hit, you need 1 fragment at (1,08/0,9) = 1,2 m2. There is 600 fragments so the spherical area of such fragmentation density is 600 x 1,2 = 720 m2.

The formula for calculation sphere area is S = 4 x (pi) x r^2 ~= 12,6 x r^2. So the radius r = sqrt(S/12,6) = sqrt(720/12,6) = 7,6 m
 
Hi Speedy,
thank you for your nice calculation. Mathematics was one of my worst subjects at school. But, I don't think that you can calculate 90% kill radius like that, without having much more data like : weight of 1 fragment, velocity(here you could enter some reasonable value), dispersion pattern (here also you could enter some reasonable value if its a ballshape). Normallly the 90% value is established in a fragment garden by tests. For a single hit to have such an effect, the fragment would have to be quite large and to have a very high velocity. So, I think that you can not calcualate this value so easily.
Regards,
Bellifortis.
 
Speedy hit the calc's right on the head and is correct in the initial determination of lethal frag distances. But you are also correct the items get tested in an arena. In my case the people needing the distance were working in an area littered with BLU families and their safety rep wanted them to post lethal frag distances. Why ??? who knows there are so many BLU 26 (and family) laying around in some places you would almost have to calc the frag distance if more then 3 went of at one time to meet the safety reps request.
 
Hi

Bellifortis: you are right, of course for the full calculation we need also to consider the energy of fragment, it's shape, weight etc. But such data aren't easy to obtain. And i'm pretty sure that from such short distance, less than 10 m, a fragment always had enough energy to injure or kill someone.

weberoed: so maybe you don't need lethal fragmentation radius but safety distance, from which the probability of kill or injure human is near zero? For this I need some data about fragments. I think the fragments in BLU-26 were steel balls embedded in light alloy shell; but as minimum I need weight or diameter of such ball.
 
There are differences in the some of the bomblets in the group I asked about. These bomblets come from the old COFRAM project (controlled fragmentation) getting the pre formed frag piece weight and size is near impossible. I have a few books that use the same formula as Speedy used, plus there are a number of other programs that give general frag distances. I also have several arena test pictures and a couple vid's which are pretty interesting.

On another note I have seen items like these go off with a soldiers standing well within the lethal range and walk away without a single frag strike
 
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