Mk84 blast radius

[Cobra360]

Fragments of a bomb case can achieve velocities from 3,000 to 11,000 fps depending on the type of bomb (for example GP bomb fragments have velocities of 5,000 to 9,000 fps). The fragmentation effects generated from the detonation of a high-explosive bomb have greater effective range than blast, usually up to approximately 3,000 feet regardless of bomb size. The fragmentation effect can be maximized by using a bomb specifically designed for this effect, or by using a GP bomb with an airburst functioning fuze.

[Weta43]

Yes, but that drops away with inverse square also...

This is well outside my area of expertise (pretending for a moment I have one) but it seems to me that - ignoring the debris, the blast will push fairly evenly over your body & pick you up & throw you, but you can survive rapid accelerations as long as the force isn't focused in particular spots - With a proper harness think of the forces acting on an F1 driver that hits a brick wall - & they get out & walk away cause the forces were distributed properly. Even the airbag in your car will (de)accelerate your head from 50km/hour to 0 in about 1/50th of a second & over a meter & you'll survive

You won't enjoy it but I doubt that the overpressure alone would kill you at that distance.

[Cobra360]

Safe escape data is generally limited to release airspeeds between 450 KTAS [Knots True Airspeed] and 600 KTAS. For the A-10, safe escape is generally limited to release airspeeds between 300 KTAS and 400 KTAS. For the B-1, safe escape is limited to release airspeeds between 340 KTAS and 560 KTAS. For the B-52, safe escape is limited to release airspeeds between 350 KIAS [Knots Indicated Airspeed]and 390 KIAS. [Airspeed may also be expressed as KCAS - Knots Calibrated Airspeed, or KGSP Knots Groundspeed].

 

WEAPON/FUSE -34 LIMITS:

 

FMU-54 / MK-82 AIR

 

 

MIN 330 KCAS

 

FMU-54 / MK-82 SE

 

 

MIN 350 KCAS

 

FMU-54 / MK-84 AIR

 

 

MIN 550 KCAS

 

FMU-54 / M117R

 

 

MIN 175 KCAS

 

FMU-139 / MK-82 AIR

 

 

MIN 280 KCAS

 

FMU-139 / MK-82 SE

 

 

MIN 310 KCAS

 

FMU-139 / MK-84 AIR

 

 

MIN 450 KCAS

 

FMU-139 / M117R

 

 

MIN 280 KCAS

 

MK-82 SE

 

 

450 to 500 KCAS

[Cobra360]

I'd say the overpressure would probably break most of the bones of your body. Overpressure would get you first and then you'd be riddeled by frags. Even if you were not killed by that you wouldn't be doing very much ever again.

[Weta43]

The fact that a peice of shrapnel will kill or maim you at 3000' doesn't mean that you're very likely to get hit by a peice of shrapnel at 3000' feet from a blast. In fact I'd say at 3000' you're pretty unlikely to get hit. The peices get far apart quite quickly, it's just that if you're unlucky enough to be in one's path, you're ferked.

[Weta43]

A 3' diameter 5' long device breaking into 1/2' square bits will have 1 peice every 7.5 sq ft at 110' from the blast - so you've probably got a less than 50% chance of getting hit by a piece. At 220' it's 1 piece every 30 sq ft. If a person is about 6 sq ft in area, that means 4 out of 5 people at 220' would not be hit by fragments.

[GGTharos]

That depends on the detonation. ;)

 

No, it doesn't. A bigger detonation will get you a bigger lethal range from overpressure effects, as will an air-burst vs. a ground-burst, but in the end the released energy is always reduced in the same manner from the point of detonation.

For the same type of weapon you'll end up calculating lethal range from overpressure the same way - put in more energy, get more range. That's it. In general, most weapons will obey something pretty close to the same mathematical equation for this, I'm sure.

 

110 feet is just slightly longer than half a city block, GG. Again...not very big...and a Mk-84 is a HUGE weapon.

 

I don't understand why people think that it would have more effect - it isn't a nuclear weapon. A 1kt warhead has less then 1km overpressure fatality radius IIRC for example. Why would you expect the Mk84, which is 1/1000 of that, to have a greater radius than 30m?

[Guest IguanaKing]

No, it doesn't. A bigger detonation will get you a bigger lethal range from overpressure effects, as will an air-burst vs. a ground-burst, but in the end the released energy is always reduced in the same manner from the point of detonation.

For the same type of weapon you'll end up calculating lethal range from overpressure the same way - put in more energy, get more range. That's it. In general, most weapons will obey something pretty close to the same mathematical equation for this, I'm sure.

 

Yes, it does. Would you compare the ignition of several hundred pounds of JP4 with the ignition of the same amount of high explosives? Of course you wouldn't, if you were a rational person. ;)

 

 

 

I don't understand why people think that it would have more effect - it isn't a nuclear weapon. A 1kt warhead has less then 1km overpressure fatality radius IIRC for example. Why would you expect the Mk84, which is 1/1000 of that, to have a greater radius than 30m?

 

Because SOME of us have a pretty good concept of what 100 ft is, and, again, its not that big. ;) No nukes required...a high order detonation equal to 1 ton of TNT at FAR MORE than 100 ft will DEFINITELY f*** you up, and, most-likely, KILL YOU. :D

[GGTharos]

http://www.gruntonline.com/US_Forces/US_Artillery/arty13d.htm

 

Table at the bottom.

 

As for the 1Kt detonation, as I -said- the lethal overpressure effects are not that long-ranged. ;) You will likely get screwed up by the other effects (primarily heat) outside the blast effect.

 

Insofar as 100' goes? It is PRETTY DARNED large. I mean, what are you comparing it to to say it's 'small'? THat is -just- the overpressure range - you have frag doing damage farther out.

[Kula66]

It would certainly toast a line of a/c ... I've had similar experience with parked a/c ... you have to hit them just so to destroy them.

 

Looking at some of the A2G videos of explosions (having never been targeted by a 2,000lb'er myself) ... the explosion cloud/crater from a 84 is way under modelled ... as for the frags ... hmmm 3000 is the min safe distance, say have a 100% saftey factor, fsay ragments COULD reach 1500' ... so I'd vote for more like anything inside 400' gets badly fragged ... enough to shred a truck, kill Igla man or wreck a parked a/c ... IMHO

[SUBS17]

In the F4:AF tac ref it says that the lethal blast frag radius for infantry out in the open is 110ft for a Mk-84, which seems small to me.

 

At 500m the shrapnel can cut you in half, even 1km away is still not safe.:D

[Guest IguanaKing]

http://www.gruntonline.com/US_Forces/US_Artillery/arty13d.htm

 

Table at the bottom.

 

As for the 1Kt detonation, as I -said- the lethal overpressure effects are not that long-ranged. ;) You will likely get screwed up by the other effects (primarily heat) outside the blast effect.

 

Insofar as 100' goes? It is PRETTY DARNED large. I mean, what are you comparing it to to say it's 'small'? THat is -just- the overpressure range - you have frag doing damage farther out.

 

What am I comparing it to? Did you NOT read what I said about half a city block? Again...pretty friggin' small in reality. Thanks for the link, BTW...perhaps you should read the table at the bottom which covers MSD for friendly troops as a guideline for FACs. ;)

[SUBS17]

I challenge you to hold a lit firecracker in your hand :P

 

The point is that overpressure effects diminish very quickly. ;)

 

Frag will likely do a good job of killing people beyond 110', but again, the effect decreases with distance - this is exactly the same effect as you have with hand grenades. You expect a hand grenade to kill everyone within some 2-3m, beyond that chances diminish quite quickly - which doesn't mean you won't get nailed by a ball bearing, it's just less likely.

 

Kill distance for a grenade is 10-20m;) Outside that you can still get killed or wounded by shrapnel.

[Kula66]

Interesting figures GGT ... strange how a 3000lb'er is a BIG jump over a 2000lb'er ... but a 500 and a 2000 are almost the same. Why is that? And why is a 750 bigger than a 2000?

[GGTharos]

What am I comparing it to? Did you NOT read what I said about half a city block? Again...pretty friggin' small in reality. Thanks for the link, BTW...perhaps you should read the table at the bottom which covers MSD for friendly troops as a guideline for FACs. ;)

 

You're out of line.

 

I also happened to read the paragraph above which says what the MSD is based on.

 

So anyway, what'st he Pk for that 110' figure? ;)

 

What's the Pk for whatever it is you're imagining?

 

(In other words, you don't seem to have any more of a clue or basis of comparison than I do)

 

 

Kula, could be for a number of reasons, such as a larger number of fragments, or a larger proportion of explosive, etcetc.

[Kula66]

Checked on the explosive content ... doesn't compute ...

[Weta43]

How about rather than just everybody saying " it seems small", "it seems too much" maybe S/one could just work out some rough probabilities.

There's bound to be s/one here with the total weight of the 84 to hand. take away the weight of the warhead & assume say 80% of the remaining weight turns into fragments. Pick a size for them, get the specific weight of steel off the internet & work out how many of those sized bits you get from that much steel (size gives you volume, volume gives you weight of each bit).

Assume a person is - what - 6sq ft? - same as the combined area of teh block & box on a vehicle? Work out what radius gives a sphere with a surface area such that the probability of any 6 sq ft area getting hit by a fragment is 60% (about 1 every 10 sq ft) & make that the lethal range.

Or use & give some better assumptions.

Post the weights here in the next 15min & I'll do it..

[Kula66]

Have a look at http://www.fas.org/man/dod-101/sys/dumb/index.html ...

[Guest IguanaKing]

You don't think I read that paragraph as well? What do you mean I am "out of line"? BTW...since those figures of MSD are in meters, you should multiply by, roughly, three to get feet. BTW...I have just a little bit more of a "clue" about this than you seem to realize.

[GGTharos]

Correct. And that still says nothing about overpressure effects - they're strictly concerned about fragments penetrating the skin.

 

Everything I've read has -always- suggested that the overpressure effect was not the major kill mechanism of a bomb at range - it's /always/ frag.

 

Unfortunately, finding any useful documentation for this discussion is proving pretty fruitless. :(

[Weta43]

Yes a fragment might kill you at 1km, so might a bullet from an AK47. But what's the chance of s/one hitting you at 1km - & they're aiming specifically at you. So it's lethal if it hits you, but odds are high it won't. Are you inside an effective lethal range or outside?

[Cobra360]

It could depend on the bomb filling. Demolition bombs use more explosive material at the expanse of frag damage. While frag bombs use less explosive material. There are no frag bombs in the US inventory any more as demolition bombs a deemed to have enough frag damage.

 

For a 2,000lb er the lethal blast over pressure radius for infantry is said to be 110ft yet frag resulting from that can be lethal out to around 3,000ft regardless of bomb size. Bomb size mainly effects blast radius size and not frag radius, just frag intensity, as a bigger bomb casing has more poetential frag material. Thats what I can make sense of from various sources anyway.

[Kula66]

GGT, I think that depends on the bomb ... a Daisy Cutter has very little frag effect and all blast ...

[Guest IguanaKing]

Just out of curiosity, what is everyone's definition of "kill" in the PK?

[GGTharos]

Do you know what the weight of that thing is?

 

In addition, the explosive is dispersed over a rarge area before detonation - it's a completely different type of weapon.