How destructive is a real-life WW2 75mm HE tank shell?

[Bulletpoint]

I suppose most of the damage to soldiers would be caused by shrapnel, but how physically destructive would the actual bursting charge be?

Please, no links to grisly pages. I would like to know what kind of damage would be caused to things like a brick wall, a tree, etc.. can't seem to find any real info on the web about it.

[womble]

Actually, by WW2, ordnance designers had realised that shrapnel wasn't the biggest component of the havoc HE munitions wreak. Designs were maximising filler (rather than replacing mass/volume with "grape shot"), in order to get the greatest blast effects out of a given shell mass and shape.

[Bulletpoint]

Actually, by WW2, ordnance designers had realised that shrapnel wasn't the biggest component of the havoc HE munitions wreak. Designs were maximising filler (rather than replacing mass/volume with "grape shot"), in order to get the greatest blast effects out of a given shell mass and shape.

That's interesting, I didn't know that. Perhaps it's due to debris and pebbles making up for the smaller amount of metal shrapnel.

So, anyone knows how big a hole a tank shell makes in a brick wall?

[womble]

That's interesting, I didn't know that. Perhaps it's due to debris and pebbles making up for the smaller amount of metal shrapnel.

Not as I understand it; the compression ("blast") wave of the HE detonation is what does the damage to people, and, close up, structures. AIUI, shrapnel is largely irrelevant close to the point of detonation (the blast is more than enough to kill you), and serves mostly to extend the radius of lethality-to-personnel, and shrapnel isn't a great leveller of buildings at any distance from the point of burst.

Of course, if the larger explosion happens to set a lot of hard, sharp fragments of environment in motion, you will get the best (or worse, depending on your viewpoint) of both worlds.

It's probably not as simple as I'm laying it out, and there's probably a point of size (grenades, AP land mines, light mortars) below which adding some fragments is more effective than adding explosive because you want a larger lethal radius more than you want intense blast, and have no aspirations to property damage.

Not that that helps address your main question Sorry.

[YankeeDog]

Actually, by WW2, ordnance designers had realised that shrapnel wasn't the biggest component of the havoc HE munitions wreak. Designs were maximising filler (rather than replacing mass/volume with "grape shot"), in order to get the greatest blast effects out of a given shell mass and shape.

Eh... not exactly. What they realized is that a thin-walled shell with a higher HE load produces a large number of small, but very high velocity fragments. The velocity makes up for the small size and these fragments still have more than enough energy to incapacitate.

In contrast, a thick-walled shell with less HE produces fewer, large fragments with a lower velocity. These large fragments are quite deadly but since there's fewer of them they don't cover the area of effect as thoroughly.

Regardless, the primary wounding mechanism is still from the shell fragments, not the "blast." Even for a thin wall, high HE load shell, the lethal blast radius from something like a 75mm HE shell is very small and on average only produces a small percentage of the casualties against a typical infantry target. Casualty records show that the vast majority of casualties from artillery and other types of HE fire are shell fragment injuries, not blast-type injuries.

[womble]

Oh. My misunderstanding there, then.

[MikeyD]

Interestingly, the more modernized the guns got the less effective the HE became. The US 75mm round could trace its origins all the way back to the French 75 cannon model 1897(!). German Panther 75mm HE and British 17 pounder HE were said to be less effective due to the need to thickened the round walls to withstand the high hamber pressures. Extending this to modern day, Stryker MGS mounts a 105mm high pressure gun BUT its primary munition is a low-pressure squash head round with a very low muzzle velocity and hardly anything at all by way of shell body. Its almost all HE filler.

[Michael Emrys]

Extending this to modern day, Stryker MGS mounts a 105mm high pressure gun BUT its primary munition is a low-pressure squash head round with a very low muzzle velocity and hardly anything at all by way of shell body. Its almost all HE filler.

But is the main purpose of such a round anti-personnel wounding or demolition of cover or obstacles?

Michael

[GLynn41]

The Sherman M_3 75 mm carried over a pound of HE filler-one and a half pounds IIRC- the fragments were around #800-1000 pieces in a butterfly pattern in the direction the shell was going when it exploded - largest frags are ant the front and back-- largest amount out the sides- the 76 mm had only 8 oz or so of He filler

the 75 had kill radius of 20-30 meters//depends on who you read after-- and is dangerous upwards of three times that distance

[postfux123]

One of my teachers told a story of tanks firing at our school (or rather the SS firing from it). That most likely would have been Shermans against a massive stone wall not causing structural relevant damage but making quite a mess. My grandfather told of a direct hit (no idea by what weapon) against a wooden structure pretty much bringing it down.

Thats very vague, but the best I have to offer.

[Hister]

A massive amount of calculations would need to be done for proper "destruction effect" on objects. Hope CM tackles it one day. Current destruction model to buildings definitely needs a more detailed visual and hardcoded representation.

[John Kettler]

Bulletpoint,

Here is the principal data on the 75 mm M48 HE shell used on a bunch of AFVs, including the Sherman.

http://64.78.11.86/uxofiles/mulvaney/techdatasheets/75mm-GUN-HE-M48.pdf

The destructiveness of the shell is a function of target type and fuze setting. Default is Fuze SQ (Super Quick), which detonates on contact. Delay settings on the PD (Point Detonating) setting are either 0.05 seconds or 0.15 seconds and are used for penetrating structures before detonation and for ricochet fire.

There is no hard answer for the projectile's destructiveness unless the engagement parameters are very well defined. I can say that 75 mm HE fire on Delay from a Crocodile blew apart a wooden house. This is reported in Wilson, Flame Thrower. Effectiveness vs a stone wall is a function of wall material, wall construction, state of repair, wall thickness and more. A stone wall separating, say, farm fields is one thing, whereas stout house walls of stone are something else altogether, and that's without considering the type of stone used.

This should give some sense of relative destructiveness from blast. Admittedly, this is 105 mm HE, not 75 mm. The 105 mm HE is not even twice as powerful as the 75 mm when it comes to blast, because to double blast, the weight of explosive has to be cubed. The cube of the explosive weight for the 75 mm HE is 3.3 lbs, and the 105 HE has a TNT fill of 4.8 lbs, as seen here.

http://64.78.11.86/uxofiles/mulvaney/techdatasheets/105mm-HE-M1.pdf

Demolition fire vs earth infilled log roadblock 4" thick. Sequence begins at 10:22.

Regards,

John Kettler

[postfux123]

Having spent a monday in the office I found this one:

http://www.bote-aus-der-buckligen-welt.at/flash/bote149/files/assets/pages/page0024.swf

weapon: russian tank - not very helpfull again

[Bulletpoint]

Thanks everybody for your comments and answers.

The 105 mm HE is not even twice as powerful as the 75 mm when it comes to blast, because to double blast, the weight of explosive has to be cubed. The cube of the explosive weight for the 75 mm HE is 3.3 lbs, and the 105 HE has a TNT fill of 4.8 lbs, as seen here.

So, to be twice as powerful as the 75mm, it would need at least 3.3 lbs. of HE. But if the 105mm has 4.8 lbs. then surely it is more than twice as powerful?

[John Kettler]

Bulletpoint,

In the cold light of day, following a terrible and all but sleepless night, I now painfully see I screwed up. And can't fix the blasted post! The 75 mm HE has a 1.49 lb TNT fill. To double that blast yield, the other shell under evaluation, the 105 mm HE, must have a fill equal to or exceeding the cube of that number, which is 3.3. The fill of the 105 shell is 4.8 lbs of TNT. It is, therefore, more than twice as powerful. Sorry for the confusion!

Regards,

John Kettler

[c3k]

The design of weapons has gone for a more "even" footprint. As mentioned above, thick walls produce large, irregular fragments. They go quite far and are quite nasty.

Wounds are similar to high velocity sabre wounds; a British soldier, standing in a field had both legs amputated at the shin, for example, from a round which went off about 100 yards away. Meanwhile, several men within spitting range of the explosion were completely unharmed.

The ability to fine-turn metallurgy allows for metal crystallization to form in a specific manner which helps create these shards.

These wound mechanisms aren't reliable enough.

Rather, the new approach has a much more dense field of fragments which assure wounding within a certain radius of the impact. Given that radius, and the number of men, and their cover, you can calculate how many rounds will produce a % of casualties to them.

See a company in light field works and you want 50% casualties? Hmm, spin the death-o-meter, and tell the arty how many of what type to fire.

Small filler, thick walls: big chunks that go far and are sporadic in coverage.

High filler, thin walls: small pieces that give uniform coverage over a short range.

(Large bombs are tuned for this effect: the casing shears at a uniform sharp angle, producing hundreds of spinning "swords", 2 to 4 feet in length. The edges are, literally, razor sharp.)

[c3k]

Here's an image:

Cut a bomb shell in half and look down it: O.

That annular cross-section zoomed in, upon detonation, produces these: <-- //////// --> (Imagine they continue in a circle. This is just a small section of the circumference.

Each "/" from the top the character to the bottom ( _ ), is the thickness of the bomb case, about 1 1/2 inches. That's the cross-section. The edges, as stated, are razor sharp. If you handle it, you'll slice your fingers open. (Ask me how I know.) Plus, along it's length (think of a sword, because that's what they look like. The curve follows the bomb shape.), it's serrated, based on the metal pattern. They're up to 4 feet long. Whizzing about at supersonic speed after detonation.

'Nuff on bombs.

Arty shells are similar. Or were. Now, the frag pattern is the standard, or the frag warhead.

[Daroc]

Here's an image:

(Ask me how I know.)

Ok, I'll ask.

[c3k]

Grabbed hold of one. Several bloody fingers later, I decided not to grab it that way again.