LW cannon ineffective against tanks?

[Fishu]

At least luftwaffies in this airwar are real heros... fightning with peashots and bricks, while allies are killing with UFOs.. right!

[flakbait]

 

I wish we had some ordinance experts around here that could tell us the effective blast radius of a 500lb bomb.

You asked for it!
The maximum effective blast radius for a 500 pound HE bomb is 83.5 feet according to a Vietnam vet I know. He approved the Arc Light [B-52] strikes, and received the BDA reports. The Air Force manuals only admitted a 50 foot blast radius, but from what he's seen and read anything beyond 85 feet wasn't touched by the bang. Except, of couse, glass. He told me he's seen a 500 pound bomb hit as close as 20 feet from a mud-log bunker the VC build and not flatten it. Amazing. Against tanks, about the only thing you can do is hit one directly. A bomb strike within 20 feet or so might throw a track, but with the side plating on out Panzer IV the fragments wouldn't be all that effective.

From what he told me "If you really wanna kill something like a tank, you've got to plant that bomb right on top of him. If you wanna damage him, use 1,000 pounders and lay 'em down real close. If you get lucky, you might kill him with a near miss."

Flakbait
A man standing in the shadows of giants

[Greg 'wmutt' Cook]

 

The maximum effective blast radius for a 500 pound HE bomb is 83.5 feet according to a Vietnam vet I know.
<snip>The Air Force manuals only admitted a 50 foot blast radius, but from what he's seen and read anything beyond 85 feet wasn't touched by the bang. Except, of couse, glass.

You sure that's feet or meters?  
A lot depends on the type of fusing that is being modeled.  General purpose demolition bombs were fused basicly 2 ways (i know that there were several target specific fusing methods, but they are not relevent to this discussion): Surface blast, or delayed action.  The delayed action GP demo bombs were found to be vastly more effective.  The Detonation train of a GP(d) was something like this: Primer (various highly sesitive materials were used for this), Delay (normaly compressed black powder that required around a 1/10 of a second to be consumed) Mercury Fulminate detonator, followed by a tetryl booster, and then the main charge of ammonium-nitrate or composition B.  I can't without digging through my old engineer demo manuals (burried under 10 years of civilian life in the garage) do a demo calculation on a 500lb bomb.  But I do have the Airforce figures for a 100 bomb from a study in 1944.  A 100 lb GP bomb surface detonated on sandy soil (normal dirt) left an avarage crater 2 feet deep, 9 feet in diameter, and displaced 40 cubic feet of dirt.  A delayed action GP bomb tested under the same conditions left an avarage crater 5 feet deep, 20 feet in diameter, and displaced 800 cubic feet of dirt.
I think our bombs are a bit undermodeled when it comes to concusive force.  I would like to see them start fliping tanks.  In our arsenal today the US Army uses the M15 anti-tank mine.  This mine is able to flip a 60ton tank up on it's side when hit by a track.  It's main explosive charge is around 25 pounds of composition B.

------------------
Greg 'wmutt' Cook
332nd Flying Mongrels

[This message has been edited by Greg 'wmutt' Cook (edited 05-24-2000).]