"Effective radius of a 500 lbs bomb?" Topic

After watching Vietnam footage of F4 strikes and a couple of Arclight missions, I wanted to ask the following question: what is the effective radius of a 500 lbs bomb vs. unprotected human? 200 yards, 500 yards, 1000 yards? for a Vietnam era weapon.

Thanks,

Binhan

The stats I use for Afganistan games are based on the usage data in 'Joint Force Harrier'. Main thing with a 500 pounder is whether it is an airburst or a ground burst.

An airburst is around 200-250 yards against all targets not in trenches with overhead cover or in sturdy buildings.

A ground burst around half that (but is obviously more effective against targets dug in close to the point of impact).

By 'effective' I mean almost very team in the danger zone is going to get pinned with a risk of casualties or be destroyed unless they are in decent cover.

The MK-82 iron bombs have an effective casualty radius of about 60 meters according to the chart attached.

One thing to keep in mind is that they aren't dropped singly, but in pairs, or multiples depending upon the mission, thus the area covered will be overlapping blast circles.

Note, too, that the costs per unit listed are fantasy. MK-82's run between $200 USD-$300 dollars per unit depending upon the fin arrangement, whether it had retarding fins, fuze, etc.

link

IIRC, a B-52 could carry about 13 tons of bombs on a strike … I remember seeing pics of bombs clustered along the wings, plus what it could carry internally. Of course now B-52s can carry SLAM Cruise Missiles as well, IIRC …

Fragmentation range is important to look at … There will be larger and large fragments that travel a long way. Density falls off sharply because of the combined effects of the distribution of fragment sizes (few large fragments) and the effects of the square law, but you still need to watch out, especially for larger, soft targets like trucks.

ouch!

An airburst is around 200-250 yards against all targets not in trenches with overhead cover or in sturdy buildings.

Two football fields plus in any direction seems to me to be somewhat overly wide, even for an airburst. As emckinney mentioned, at that range the fragmentation effect would be greatly diminished by dispersion, and the concussive effect would also have dropped a good bit.

Doug

Doug,

Agreed. I spoke with an Aviation Ordnanceman (Navy) I served with and he said a 500lb iron bomb had a lethal fragmentation area of around 100yds.

As I posted above, they are almost always dropped in pairs, or multiple pairs, so that you'd have a string of overlapping blast circles along the flight path.

Also, most of the proximity fuzes for airbursts aren't used anymore, as the cluster bombs are much more effective for that purpose, as is field artillery.

Key word is *lethal* fragmentation area. A basic M67 hand grenade has a lethal radius of 5m and an injury radius of 15m.

And what do you want to bet that the ordie hasn't even seen an airburst fuze since A-school, so he gave you the ground-blast radius (which would fit nicely with what Martin said)?

An airburst is around 200-250 yards against all targets not in trenches with overhead cover or in sturdy buildings.

A ground burst around half that (but is obviously more effective against targets dug in close to the point of impact).

By 'effective' I mean almost very team in the danger zone is going to get pinned with a risk of casualties or be destroyed unless they are in decent cover.

I'd call it a 30m "everything's dead" radius and a "pinned and check for casualties" radius of 100m.

"Two football fields plus in any direction seems to me to be somewhat overly wide, even for an airburst."

I'm only quoting what the pilots said, and those were the guidlines used by the FACs for weapon selection. It doesn't mean that everyone within 250m of the bomb is killed, but it will suppress that area. I'm pretty sure no-one used 500 pounder airbusts in Vietnam though as I don't think they had the fusing tech then.

In my damage model there are three zones of lethality, in the outer ring (outer 50% of radius) suppression is the only likely adverse outcome, things get a bit more dangerous closer in if targets are not in cover and very dangerous indeed in the (small) lethal inner zone.

That very dangerous ring for a regular 500 pound bomb the blast radius (injury from blast pressure) out to 13 meters, beyond that you are seeing the principle would generation being fragment (bomb bits) or shrapnel (everything else that has been sent flying.

Standing at 700 feet you have a 1 percent chance of being hit by a lethal fragment. Fragmentation normally travel beyond 4,300 feet, large pieces like base plates can travel well over a mile.

The blast pressure is amazing too. Anyone within 50 feet should expect to die from nice things like lung hemorrhages, air bubbles in the circulation system, organ bruising and swelling.

Thanks for the info. I'll probably go with the 100 yard radius for automatic wound and pinned and the 200 yard radius for possible wound/pinned.

-Binhan