The 'fireball'- and it is really just an almost instantaneous flash over(Unless there is a secondary)- is usually somewhat smaller than the blast radius, and is therefore generally not a factor in wounding- though it will obviously ignite flammable liquids and gases.
The blast radius could also be called the concussion radius, or overpressure radius. It is 'generally' 1/2-1/4 the size of the lethal radius(fragmentation radius), depending on the given munition type and especially the fuzing.
If you have a hard target and you want to dig it out you request fuzing to be set to HE-D(High Explosive Delay), and keep your FFE in a tight cluster centered on a precise 8 or 10 digit grid(10 digit for GPS).
This packs the ordnance together and the Delay(.01 sec) fuzing allows it to penetrate several feet of concrete before detonation. You generally need a direct hit or a very near miss to destroy bunkers, armored vehicles etc with anything up to 155mm.
At 8"(203mm) you start to get some serious shock damage and can collapse bunkers/toss APC's with reasonably close misses.
The 16" shell is a WHOLE different category. That(HE-D) creates a crater 45 feet across and 30 feet deep.
The shock and over pressure damage of a nine gun salvo is awe inspiring to behold- even in photo's.
Iowa's have cut the top 30-40 feet off of mountains in Korea and Vietnam, and actually literally severed several acres of Tiger Island off the coast of Vietnam during the war.
During the Normandy landings a British battlecruiser with 14" guns(i think it was a brit ship) shelled Nazi Panzergruppen attempting to reinforce the Atlantic wall and tossed 50 ton Tiger tanks on their back after near misses as far away as 50 feet.
Rommel commented that he could do nothing against the Allies heavy battleships- he could not reinforce, he could not shift his forces, and he could not withdraw in an orderly fashion.
LOL, little did he know they weren't even battleships.
For APERS duties against TIO(Troops In Open), you want to use VT-fuzing(Prox), and may wish to call for walking fire if the enemy troops are moving, or TOT(Time On Target- my favorite

if they are stationary. With GPS aids FO's can normally dispense with the adjusting round and go directly to the FFE. That is a huge improvement in the effective lethality of artillery fire.
For troops in trenches and fighting holes- or soft skin vehicles you want a mix of of VT and HE-Q(Quick timed- IOW contact, .001 sec).
I know you like airpower, but 85% of casualties in war are historicly caused by artillery.... figured i'd point that out
Edited by - m21 Sniper on Feb 04 2003 10:58 PM