Artilery Airburst effects on tanks

[Fionn]

Mike,

Well, I didn't say great . Someone else said that. HE in shells was rare after 41 really since they figured out it wasn't much use.

Thus you're more likely to find it in sub-75mm shells since those were the early war shells.

[Rattus]

Fionn, Mike,

Can't speak for German AP but Allied AP definitely (I'm looking at Hogg's Birt & Ami Arty of WWII, which includes many allied tank guns) adopted burster charges during the war. E.g for US 3" AT gun, M79 AP (no cap no burster) replaced by M62(!) APCBC containing burster. Similary for Sherman's 75. The US 90mm was originally issued with the solid M77 AP round - but this was declared substitute standard & replace by the APHE M82 round. The only exception was for HVAP rounds. Whilst it is true that a solid tungsten round (at much higer m/v) can cause

more high velocity splinters (if nothing else!) than an ordinary AP round with burster, the AP round with burster produces splinters with a higher velocity and greater spread than an equivalent solid steel AP round at the same mv. That is the purpose of the burster - not to casue damage by "blast" effects. With really small rounds, the difference becomes less significant. The 2pdr AT gun had an APHE shot developed for it but tests showed it to be only a marginal improvement over the solid shot - & there were problems with losing the base fuze. Similarly the US 37mm used only solid AP shot.

The presence of the burster makes little difference to penetration, but compared to solid shot at same mv increases lethality & permanent damage IF a penetration is achieved. A solid tungsten APCR/APDS round is travelling at such a higher mv that it's splinter causing capacity leaves the others for dead. It needs no burster to do the job disregarding the manufacturing/engineering problems with putting one in. It was the widespread adoption of the tungsten penetrator that spelled obsolecense for the APHE round.

Michael

[:USERNAME:]

Just want to add that HE effects falls off at about an inverse cube, or 1/x^3. So the closer the better of course but the further the very much less effective.

Todays armor has (or should have) baffled armor plates over the radiators, etc. Sometimes with Kevlar slabs under the steel baffles (alternating slanted armor) so as to defeat airfrags (yeah johns right, they are splinters not frags).

WWII electronics were tube based and fragile. HE detonations would play hell with them and the antennas of course. Either way communications would be hindered/stopped as the poor radio guy swapped out fuzes to get his orange glow again.

Ive read that tanks like the sherman had weak armor over the tracks (under the sponsons) and ricochets and big frags were a problem till this area was reinforced because ammo was stored directly there. Perhaps other vehicles also had this problem. We can guage HE arty effects on armor by looking at land mines. Consider the HE content of a landmine and the need for a "direct hit" of a vehicle running it over. Theres no velocity component of course...

In general, Indirect HE, either ground detonating or airburst, would need to be in very close proximity (meters)to the armor to have a KO effect. Other effects listed here might extend up to a dozen meters or so at best (for 150mm shells and above). Antennas, vision blocks, C-Rats, etc would be vulnerable at greater ranges. Carburators on gas run tanks might flood, stall the vehicle from a heavy detonation.

Airbursts really kick ass on infantry and everyone should read Burgetts account from his Holland book where his company of airborne after landing get slapped around by 3 88 AA guns firing into the woods they are crossing. The shells are definitly exploding in the air from treebursts (or time fuze) and take out 30 percent of the troopers. I want to make a point here that HE shells with point detonating fuzes in WWII might have been extremely sensitive (and not self burying). Company commander by MacDonald states that pine tree tops detonated tank shells at the top of the trees. The germans had a variable time fuze on alot of tank HE shells and could either have it point detonate or delay with an adjustment up to 0.15 seconds). So if they wanted a shell to explode against a wall to clear out a street of infantry they could use PD. If they wanted to get an internal explosion in a building, they would delay the explosion. Again, Burgett describes a german weapon invading the house walls as everyone is making a dash for the cellar. Ive also read of GIs getting killed without a scratch from these deadly confined explosions. Sometimes getting flung about and stripped of boots/clothes. Kind of wierd.

Lewis

[This message has been edited by :USERNAME: (edited 08-19-2000).]

[19 Echo]

Speaking of Charles MacDonald, here's a quote from A Time For Trumpets:

"The German tanks became even more vulnerable under the pounding of the 2d Division's four artillery battalions reinforced by three corps battalions, for even when that fire failed to knock out a tank, it might break a track or a sprocket wheel...."(p. 398)

MacDonald relates many instances where German tanks were turned back by artillery fire (at one point there were 348 guns backing up the Elsenborn Ridge defenses, from the 105mm howitzers of the regimental Cannon Companies to 8-inch howitzers of corps artillery), and states that "the artillery turned out to be the most effective antitank weapon of all."

-- Mike Zeares

[dNorwood]

<BLOCKQUOTE>quote:</font><HR>Originally posted by John Kettler:

blast falls off dramatically as range decreases (forget the exact mathematical expression, though).

John Kettler <HR></BLOCKQUOTE>

John,

A simple-minded conservation of energy argument would suggest that the blast would derease the the inverse square of distance - is it that simple (and if not, is there a simple explanation for the deviation)?

[:USERNAME:]

<BLOCKQUOTE>quote:</font><HR>Originally posted by dNorwood:

John,

A simple-minded conservation of energy argument would suggest that the blast would derease the the inverse square of distance - is it that simple (and if not, is there a simple explanation for the deviation)?<HR></BLOCKQUOTE>

Its an inverse cube professor

[John Kettler]

In light of the burgeoning discussion on this topic, it would be great to hear from current/former artillery types about the range of artillery fragment sizes and weights for common HE artillery rounds (75mm/105mm/155mm or similar) and mortar rounds (60mm/81mm/107/120). I believe this would be a big help to many in understanding what we're trying to describe in this thread.

Can anyone put some real numbers to our hypothetical discussion?

Sincerely,

John Kettler

[:USERNAME:]

As a motion control engineer, I want to say that the ballistic properties of splintering shells are pretty bad. The smaller ones scrub their velocities quickly.

while a bullet can be fired in the air and represent a danger on the way down, the same is not true for splinters. Shrapnel shells are different with preloaded spherical balls that have enough weight and a fairly decent shape to represent as much danger as say a riffle from the 1800's. Perhaps hundreds of yards.

In heavy payload arty and aerial bombs, an airburst has great effect to the point of flipping vehicles. I believe A10 aircraft prefer these nowadays when not firing maverick. But arty of about 105mm and lower would be better off with a ground detonation against fullly armored AFVs. Theres the chance of getting one directly on/around/under and it would pay off better than an airburst.

Lewis

DNorwood you really a teacher or just putting us on? There is a teacher with your name at the university with your mail name. I have seen some of his work on light scattering (digital imaging research).

[WARPIG101st]

I can't give any factual numbers but I can tell you what I have witnessed while I was ARTY. I currently posses a peice of "shrapnel" from a 155mm shell that was produced in 1944 and was fired during a NTC rotation in 1998. It is 14 inches long and was found inside of an M60 tank where the loader would be sitting. That particular fire mission we fired PD and there was still enough power to puncture the turret. So I would have no doubt that an airburst round could easily immobilize anything available durring WW2. By the way I spent 7 of my last 8 years as a connon fire direction specialist (13E) in the U.S.Army

Shandorf, it's good to see other people from my hometown. Used to live over by Birchgrove Elementary.

[This message has been edited by WARPIG101st (edited 08-19-2000).]

[Guest Michael emrys]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Fionn:

Mike,

Well, I didn't say great . Someone else said that.<HR></BLOCKQUOTE>

True, you didn't. Even the article Kwazydog quoted didn't. It did use the word 'common', which in this context is a sufficient synonym for 'great many' I think. Anyway, that's what I was responding too.

<BLOCKQUOTE>quote:</font><HR>HE in shells was rare after 41 really since they figured out it wasn't much use.<HR></BLOCKQUOTE>

This is kind of what I would have thought. In the previously mentioned article, it was somewhere claimed that the blasting charge "finished the job of penetrating the armor", or words to that effect, which sounds totally bogus to me. I expect the blasting charge, if present, would have been intended to harm the crew and interior of the vehicle *after* the armor had been penetrated. In fact, since a shot containing a blasting charge would be slightly lighter in weight, I would have thought that its penetration performance would be slightly degraded. There is also some question of it being more likely to break up upon striking the armor, though I suppose that is an engineering problem that would yield to good design.

Michael

[:USERNAME:]

I forget the book but it was about St Lo and was written by a major in the US army (Johns?). there was an ASL scenario based around an attack by german engineers on his position at night?

Anyway, he claimed that 4.2 inch chem mortar HE rounds would splinter along the walls into these long shards (about a foot)that would cut a man in half. He also describes that medium splinters would put such a neat hole in a mortar tube (steel) that it would look like it was expertly drilled. While this is nice, it certainly isnt optimal. Theres alot of 'live' space where you would survive in a case where the shell fractures into these large shards. Its not the best anti personnel effect is my point.

A arms company realized this and produced mortar rounds that were internally scored to enhance this for anti vehicle effect. With todays HE and good steel they would certainly defeat aluminum armor/steel-tracks and maybe even fortifications. I dont know if many nations bought these.

Last thing is that sherman tracks in NO way compare to german tracks. They are largely rubber and the german tracks are hardened steel. I always think its funny when I see a sherman 'bolstering' itself in WWII pictures.

Lewis

[John Kettler]

WARPIG101st,

If possible, please provide a full set of dimensions for this shell fragment, some description of its shape, and its weight.

A photo or photos (w/ visual scale in frame) would be most useful.

Also, please clarify what you said concerning what that recovered fragment did to the M-60. Are you saying that this fragment had so much kinetic energy that it pierced the turret of an M-60? If so, what part of the turret was pierced? Was the tank buttoned at the time? Any details would be most welcome.

Thanks much! This is precisely the kind of response I was looking for. Anyone else?

John Kettler

[:USERNAME:]

Warpig is claiming a 50 year old shell was fired? maybe it was repacked? I wouldnt pull the lanyard on that sucker.

[WARPIG101st]

The fragment is 14 inches long by about 1 inch wide and 1\2 inch thick weighing about 5 pounds. It looked like the fragment entered lengthwise between the matting surface of the turret and the hull, effectively a fast moving sawblade. The vehicle was buttoned and the round landed aprox. 10 meters from the side of the vehicle. As far as the age of the round it is true that it was 50 years old. So much ammo was produced during the war that we still find shell lots that were made back then. Even the Airforce still uses bombs from Vietnam and sometimes older. the age of the shell really doesn't matter anyway it is the age of the powder that is important.

------------------

The only thing more accurate than incomming fire is incoming friendly fire

[This message has been edited by WARPIG101st (edited 08-20-2000).]

[Guest Michael emrys]

Some units in Viet Nam were issued turkeys for Thanksgiving that had been frozen in 1945.

Michael

[willys]

Somehting I think pertains to this topic as well is the concept of scale. In the wargame West front there is a reasoned explanation why the designers chose not to have indirect rounds be a causative agent in tank/armor damage. The showed a photocopy of a report prepared by the us army which showed that less than 3% of tank kills of the ones studied could be traced to indirect fire. (Check it out it is in the very back of the manual if you have the game). But WF is an operational game with much larger maps. Even one hex is equivalent to 250 meters per side of the hex area, creating quite a large targeted area. On this scale a platoon of tanks (say 5), could be widely dispersed within this area and the probability of a round getting close enough to actually damage armor is significantly reduced. On scale with CM you have a much more scaled down area where this could be several rounds landing in a much smaller target zone. I don't feel that there is any question that a 155mm shell landing close enough to an armored vehicle could cause disabling damage, but again it is the scale of the game which could heavily influence this happening.....see my point?

[jshandorf]

<BLOCKQUOTE>quote:</font><HR>Originally posted by WARPIG101st:

I can't give any factual numbers but I can tell you what I have witnessed while I was ARTY. I currently posses a peice of "shrapnel" from a 155mm shell that was produced in 1944 and was fired during a NTC rotation in 1998. It is 14 inches long and was found inside of an M60 tank where the loader would be sitting. That particular fire mission we fired PD and there was still enough power to puncture the turret. So I would have no doubt that an airburst round could easily immobilize anything available durring WW2. By the way I spent 7 of my last 8 years as a connon fire direction specialist (13E) in the U.S.Army

Shandorf, it's good to see other people from my hometown. Used to live over by Birchgrove Elementary.

[This message has been edited by WARPIG101st (edited 08-19-2000).]<HR></BLOCKQUOTE>

Yes, yes. Good old BP. Say.. Since we are in the same time zone we should start a PBEM sometime. Currently I am playing a game with Fionn and I after that I am going to upgrade to 1.04 so in the meantime I don't want to start any new ones. It may take a while since Fionn is 6 hours ahead of me getting our turns to each other is really slow.

Lets stay in touch.

Jeff