Richard Anderson wrote: ↑
16 Nov 2021 01:41
Carl Schwamberger wrote: ↑
15 Nov 2021 17:42
For your shock effect the 500 yard radius is what you want to consider. It might be a bit smaller but fussing over 50 meters might not be the best use of time here.
What size bomb are you talking about? These are 100-lb, 250-lb, and 500-lb bombs. Again, for the B-17 the choice was 52 100-lb or 12 500-lb bombs.
A 155mm cannon projectile M107 with PD fuze weighs 42.2kg & has (from memory) 6.9kg explosive. Again from memory, vs a entrenched defense position with overhead cover of sandbags over steel stakes or timber 90 rounds would be required for initial Neutralization of a 350 meter dia target. Thats 3,807kg, a bit short of four tons projectiles. Extrapolating upwards for a extended Neutralization of that target of 20+ minutes x4 projectile would be fifteen tons. John McManus maps of the US 1st Div assault show the W-61 & W-62 to be apporx 300 & 500 yards Dia respectively. We never planned Neutralization attacks on hard targets like concrete bunkers. Suppression was the preferred technique. Scaling up x2 to 30 tons cannon ammunition would put you in the zone for inflicting the desired level of shock and bleeding ears on men better protected inside concrete. In one of these multiple files on my computer there is a dispersal study for the high altitude attacks of the 8th AF. But, I'm getting mental fatigue & have a few other things on other subjects to get at. For the moment a back of the envelope calculation will assume 25% of bombs hit inside the 500 meter circle. Balkowski has a chart showing nine Wn. targeted with 88 or 82 tons, One with 107 tons, and three with 129 tons. With 25% inside this effect zone gives you 22, 27, 33 tons on target. If its 50% then 44, 53, & 65 tons on each Wn.
I don't know how accurate McManus sketch maps are. For w-61 they show three Tobrucks, two MG & one Renault turret, Also there is a bunker, presumably concrete wi a AT gun, & oddly a AT gun depicted in the open. Presumably that was in some sort of pit/ revetment structure. W-62 is shown with two mortar & one MG Tobruk; Five bunkers three MG, One 'cannon;, and two AT guns; and two cannon & two MG depicted without surrounding bunkers. This suggest not everything was under concrete, but we'd want some collaboration of that.
Temporary concussion from overpressure, temporary hearing loss, and fear. The artillery Effects Tables & guides we used considered 0-2% physical losses sufficient to 'Suppress' a target, & above 2% sufficient to 'Neutralize' the same. I don't have precise information on material damage in W-5, but every account or description leads to it being Neutralized for the following 20-30 minutes. Maybe there is something somewhere that supports they were putting out effective fires on the beach crossing, but I've not seen it yet.
I'll see if I have any of the particulars. IIRC, one of the 4.7cm AT (f) were knocked out, but that was it. The main effect IIRC is the garrison was stunned and did not want to come out of the shelters.
Some claim there was a 88 in W-5, & variously claim it was damaged, or jammed after firing one shot. There also mention of a MG knocked out.
Interpolating what I do have to W-61, W71, or wherever, leads to thinking reducing the overall efficiency of the O Beach defense by 20% or even 10% is better than 0 %. We in our practice never expected to 'destroy' a defense position, or a exposed maneuvering unit. What we hoped for was getting to the 2% or a 5% loss & disorienting the enemy unit long enough to execute our action without effective disruption on us.
Sure, any effect would have been better than the zero effect they got, but aside from changing the attack plan entirely, you also need clear skies and a ground forces command willing to accept the risk to their landing force.
To describe it in another way. If Glockel or Severloh are unable to comprehend what they doing with their weapons, are deafened, or cant even get up off the floor for fifteen or twenty minutes its a better outcome than what occurred. If a half dozen of the MG on O Beach & one or two AT guns are out of action its a bonus.
Sure, but getting there is the problem.
Im guessing you are referring to the safety margin between the bomb targets and the lead assault boats. We had a identical consideration in live fire combined arms exercises. There were variables, but a 3000 meter set back was thought the minimum. Since the ground force was sometimes stationary, & other times moving we assumed someone was approaching or touching the safety line. To keep the distance we did not use the 'delay release' technique described for the 8th AF. Halting everyone was done, but tended to discombobulate the maneuver on the ground. It did keep everyone somewhat safer, but wants though to be the best thing to do with a actual enemy in range. What we did do was extend the safety zone, or the time between bombs on target & the ground maneuver crossing the whatever marker line you are using. Balakoski places the air attacks occurring from H -25 to H-5. Bumping the air attack from H-5 to H -x or -y to increase the safety set back was our technique. There were some other techniques we used, but its late