Blast only damage

[Desert Mariner]

Does anyone know what formula is used to determine explosive blast damage? I’m working on specs for the SOHG (Scalable Offensive Hand Grenade) as a replacement for the MK3A2 but haven’t found the formula anywhere.

For those unfamiliar with the SOHG, its like grenades crossed with Legos. The user can “stack” up to three at a time to adjust the level of blast and destruction. One article on the munition puts it better than I could…“To visualize what this hand grenade offers, think about a small wooden shed that you’d buy at Home Depot. If you use just one module, you’ll blow the door open and the windows out. Select two modules and you’ll knock the shed off its foundation. But screw on all three sections and the real magic happens; you’ll transform the shed into splinters.”

It's plastic case is 53mm in diameter and comes in two sizes 85mm and 135mm, containing 115g and 225g of Comp B (Heksotol 60/40) respectively.

[mmartin798]

If you are just looking for the explosive damage as in whole body damage, you can use the RE of Comp B and do the math against the damage C4 does. Comp B has an RE of 1.01, so in the quantities you list it won't be much different.

If you are looking for how much damage the fragments do, you will need to do more math using the Gurney Equations to get the speed of the fragments and then make a guess on fragment size and run the EFactor numbers from there. I think the spherical model would still apply for just about any hand grenade. The cylindrical equation is generally used for bombs.

I hope this helps.

[Desert Mariner]

Yes, that helps immensely. I was over thinking it, figured the real answer was too simple.
Cheers!

[nuke11]

An interactive Gurnery Equations website: https://www.un.org/disarmament/un-saferguard/gurney/

It can also have 130g of PBXN-110 filler as well.

Edited: Article I used may have a transcribing error.

[Desert Mariner]

Originally Posted by nuke11

It can also have 130g of PBXN-11 filler as well.

I saw a mention of this in an article but nothing on the manufacturer's site. I also don't have a RE factor for PBXN-11.

[nuke11]

Originally Posted by Desert Mariner

I saw a mention of this in an article but nothing on the manufacturer's site. I also don't have a RE factor for PBXN-11.

It might actually be PBXN-110 as NAMMO list this as 130 gr per SOHG module. PBXN-110 is 88% HMX and 12% HTPB-based binders. It's MP RE I'm calculating as 1.12.

I'm guessing PBXN-11 is a transcribing error by dropping the 0, as I have looked high and low for a reference to PBXN-11.

[Desert Mariner]

Based on your info, looks like there are actually three (3) SOHGs:

SOHG 115-3.5 - 115g Comp B; Wt. 0.0205kg, EX 268
SOHG 225-3.5 - 225g Comp B; Wt. 0.35kg, EX 525
SOHG 260-3.5 - 260g PBXN 110; Wt. 0.35kg, EX 672

The 3.5 refers to the delay.

[mmartin798]

PBXN-109 and PBXN-135 EB both have a TNT RE of 1.17. Using MP's C4 normalized RE would make it 0.87. I didn't find PBXN-110 specifically.

[Desert Mariner]

My current thinking is to use the 115 model. My intent was to replace the MK3A2 (0.44kg; 295 EX) and the others get pretty heavy in comparison.

115 - 1 module (0.205kg, 268 EX); 2 modules (0.41kg, 536 EX); 3 modules (0.615kg, 804 EX)
225 - 1 module (0.35kg, 525 EX); 2 modules (0.7kg, 1050 EX); 3 modules (1.05kg, 1575 EX)

The 260's overall weight is the same as the 225, just a matter of figuring the best EX value for the filler.

[mmartin798]

If you want the velocity of the fragments to calculate their EFactor, you will need to know the mass of the fragmentation body. If the link above does not have the proper explosive filler listed, I can help by using my spreadsheet.

AH! Nevermind. It's not a fragmentation type, so nothing to calculate.

[Desert Mariner]

Thanks again!

Has anyone ever run the stats for the Arges HG 86 (mini-frag)? I'm considering it as an addition as well.

[nuke11]

Originally Posted by Desert Mariner

Thanks again!

Has anyone ever run the stats for the Arges HG 86 (mini-frag)? I'm considering it as an addition as well.

I have not (yet), you may want to look at the Dutch V40 as well.

Here is what I have come up for HG 86

Arges HG 86

Weight, Total: 0.18 kg
Weight, Filler: 0.017 grams PETN
Size, Length: 76 mm
Size, Diameter: 43 mm
Effective Range: 40 m - MASS 1
Fuse Delay: 4 sec +1.5/-0.5 sec
Lethal Burst Radius: 5 m
DPW: 490
E-Factor: 5 per fragment
Notes: 1600 2-2.3 mm fragments (spheres). Each fragment has a velocity 879 m/s (average fragment size is 2.1 mm)

[mmartin798]

Originally Posted by nuke11

Arges HG 86

Weight, Total: 0.18 kg
Weight, Filler: 0.017 grams PETN
Size, Length: 76 mm
Size, Diameter: 43 mm
Effective Range: 40 m - MASS 1
Fuse Delay: 4 sec +1.5/-0.5 sec
Lethal Burst Radius: 5 m
DPW: 490
E-Factor: 5 per fragment
Notes: 1600 2-2.3 mm fragments (spheres). Each fragment has a velocity 879 m/s (average fragment size is 2.1 mm)

Your specs don't match up with my research. I edited your stat block and included only the information I found or have calculated.

Weight, Total: 0.465 kg
Weight, Filler: 125 grams RDX/TNT (55%/45%)
Size, Length: 97 mm
Size, Diameter: 65 mm
Effective Range: 30 m - MASS 1
Fuse Delay:
Lethal Burst Radius: 10 m
DPW:
E-Factor: 10 per fragment (Based on fragments penetrating NIJ II armor)
Notes: 2000 2.8 mm fragments (spheres).

We may have to do more research on this to clear up the discrepancies.

[Desert Mariner]

Here's a cut-sheet for the HG 86 by Rheinmettal

...and a quote from Jane's On-line circa 2003...

Arges Type HG 86 Mini fragmentation hand grenade

Description
The Arges HG 86 (Mini 86) is the smallest type in the Arges range and is a further development of the
Arges HG 80 Mini. The principal improvement is in the control of fragment distribution. An HG 86
detonated 1 m above the ground, 5 m from a 20 mm soft wood target, averages a fragment density of
3.05/m2.
The HG 86 Mini can also be supplied as an offensive grenade (OFF HG 86) in which case it has a
plastic core without fragments and a smooth surface.

Specifications
Weight: 180 ±10 g
Length: 76 ±1 mm
Diameter: 43 ±1 mm
Weight of explosive charge: ca 17 g
Diameter of fragments: 2-2.3 mm
Number of fragments: ca 1,600
Delay time: 4 s +1.5/-0.5 s at 21ºC

[mmartin798]

Ah, I see my error. The numbers I have there are for the HG85. Different grenade.

[nuke11]

Originally Posted by mmartin798

Ah, I see my error. The numbers I have there are for the HG85. Different grenade.

What information source(s) do you have for the HG85? It doesn't seem to match any of the published information I have from many different Jane's Infantry books I have looked thru.

[mmartin798]

Originally Posted by nuke11

What information source(s) do you have for the HG85? It doesn't seem to match any of the published information I have from many different Jane's Infantry books I have looked thru.

The sources I found are below. The last one contains scans of the HG 85 manual, though it is in German:

http://www.weaponsystems.net/weapons...1+-+HG+85.html
https://www.militaryfactory.com/smal...allarms_id=435
https://www.lexpev.nl/grenades/europ...g85uehg85.html

The filler may just be TNT, though the sources conflict on this point. Since I put up those specs above, I have found a source that claims the fragmentation liner is composed of 3mm balls, which is very close to what I calculated.

[Desert Mariner]

My Jane's lists:

The Arges HG 85 is the medium size in the Arges HG range. As with other Arges designs it consists of a plastic body, an inner liner carrying the preformed fragments, and a filling of PETN high explosive.

Fragment distribution covers the full 360° area around the grenade and an HG 85, detonated 1 m above the ground and 5 m from a 20 mm soft wood target gives an average fragment density of 8.1/m2.

An offensive pattern, OFF HG 85, is available and differs from the HG 85 by having a plastic core without fragments, a smooth `lemon skin' surface and being slightly lighter.

Specifications
Weight: 340 ±20 g
Length: 96 ±2 mm
Diameter: 57 ±1 mm
Weight of explosive charge: 50 ±3 g
Diameter of fragments: 2-2.3 mm
Number of fragments: ca 3,500
Delay time: 4 s +1.5/-0.5 s at 21ºC

[mmartin798]

If we want HG 85 game specs, we need to nail down at least the weight of the filler. We have 50g on the low side and 155g on the high end. Same with the grenade weight, though I was able to calculate the size and number of fragments using the 0.1g per fragment weight I found, which puts the fragments alone at 200g. I haven't looked up the weight of the DM 82 fuze yet.

[Desert Mariner]

Is the difference in the age of the source? It seems that the entries showing the heavier grenade are all older. The three you cited appear to contain specifications from 2003, 1995 and 1985 (ish).

[nuke11]

We are looking at and talking about 2 different HG85 hand grenades.

The Arges HG85 (Austrian) is this version: https://www.lexpev.nl/grenades/europ.../splhgr85.html

The other version as discussed is the Swiss HG-85: https://www.lexpev.nl/grenades/europ...g85uehg85.html

This Swiss version seems to be cast and the Austrian version is molded. They both have different specs and that is what was throwing my searches off.

[mmartin798]

Ah, how convenient that they both share the same designation. But that does explain a lot.