"High Explosive round penetration" Topic

Does anyone have info on HE round penetration or formula to generate it? One of the only references I found was a Sherman 75 claiming to penetrate both sides of a Panzer IV turret from 100m.

Wolfhag

I always mutter at posts that say Sorry, can't help (because why bother) but in this case as well as not being able to help I'm also astonished.

I thought the idea of HE was that the fuse set it off the instant it so much as touched anything? That way it didn't bury itself well into the ground before exploding relatively uselessly.

An HE round that didn't go off after going through both sides of a tank turret must surely have been a dud or an accidentally-loaded training round, or something. Wasn't the idea that it would explode almost immediately, meaning outside the armour?

In Malaya the Commonwealth artillery gunners found that firing the 25-pounder's AP round at Japanese tanks had almost no effect on them. It just went clean through the tank, leaving a pair of matching holes 88mm in diameter on opposite sides. They resorted to firing HE at them instead because then this problem did not arise. The round exploded against the armour but still completely and reliably wrecked the target.

Good luck with your question, it's bemused me!

It is odd, maybe the question was meant to relate to Armour Piercing but then there have always been so many types and calibres of that.

The idea of a 25lb shell going through both sides of and AFV with even the thinnest armour and not wiping out the crew is amazing. Much splash of "shrapnel" from the armour itself surely? I can well imagine 25lb HE doing the job though….ouch.

Hi deadhead

The 25-pounder AP round may have been solid shot, in which case it would have messed up anything it hit, but not a lot else. At close range, it went clean through Japanese tanks.

The rule of thumb a wargaming buddy of mine used to apply was that 1lb of HE shell weight wrecks 1 ton of tank. To determine if a given HE shell wrecks a given tank, you compare pounds' weight of the shell to tons' weight of the tank.

It's crude, but it gives quite credible outcomes. A 25-pounder HE round wrecks a 17-ton Chi Ha. It is a push against a Panzer IV and doesn't trouble a Panther much. An SU-152's shell wrecks everything it hits.

The side of a Panzer IV turret was 30mm so to go through both sides requires a penetration ability of 60mm at the indicated 100m. The 75mm AP round easily had that, but as noted, I'd be surprised if the HE would have worked – unless the fuse setting allowed the explosion to be very delayed.

I like that…1lb of shell + 1 ton of tank.

I can now see what Wolfhag was getting it. I always thought a 25 lb HE shell would stop just about any AFV, if fired as a intended, as a howitzer at long range. The plunging shell hits the top of the tank, makes a loud bang and then either brings it to a halt or scratches and scorches the paint. Not too likely to happen of course, pure chance really.

Very interesting indeed thanks

You can use US concrete penetration values in various manuals and convert concrete to steel.
Or,
Here's an abstract way:
link

6. Penetration of Homogeneous Steel Plate By Projectile Fragments or By Projectiles Exploding While In Contact With The Plate

D. Penetration by Projectile Middle-Body Fragments at a Distance

Tphe(noADF) = (2.576 x 10-20)(D)V5.6084COS[2(Ob2 – 45°)] + (0.156)(D)

Tphe(ADF) = [(0.00013333)(D)V + 0.033333]COS[2(Ob2 – 45°)]

This data from TM9-1907, "Ballistic Data Performance of Ammunition" (1947). It relates to the ability of general purpose aerial bombs dropped in level bombing from a minimum of 5,000ft, and physically striking a plate of STS steel to damage or defeat said plate.

Notes:
> The left-hand value represents "maximum thickness of plate perforated without break-up or low order detonation fusing".
> The right-hand value represents "maximum thickness of plate punched through by detonation quick fusing; these perforations are obtained using an instantaneous nose fuze. Using a non-delay tail fuze should increase thickness punched through by possibly 20%."

100 lb GP – – – – – 1.0 inch – – – – – 1.8 inch

250 lb GP – – – – – 1.3 inch – – – – – 2.3 inch

500 lb GP – – – – – 1.5 inch – – – – – 3.0 inch

Notes –
> The explosive charge weight of a US GP bomb was approximately 50 pct of overall weight.
> STS plate was considered more or less equivalent to hard homogeneous armor.
> Perforation/punching ability seem to vary (more or less) as the 4th root of the explosive weight.

FWIW.

B

Fuses were removed from HE shells before firing to allow them to function as ersatz AP.

1.5 – 2.5 X the diameter of the HEAT round for WWII, range is immaterial. Modern HEAT rounds are much more effective.

pjm

Thanks guys, that's what I was looking for.

Ethan, didn't 75mm HE use super quick, delayed fuses (0.05 to 0.15 seconds)? Delay fuse lets the round penetrate a gunshield or building and explode inside. The delay could also ricochet off the ground and explode as an airburst 25m-30m from impact if on firm ground. Super quick explodes on contact.

Here is a good site for the 25lb gun:
nigelef.tripod.com/anti-tank.htm

25lb Mk 2 AP penetration at 30 degrees:
62 mm @ 500m
54 mm @ 1000m

The British did an experiment running a Churchill through a 25lb barrage (WO 291/399). The results were that direct hits on the roof caused no adverse effect to the crew and the armor was not penetrated.

Dumb artillery against tanks: imgur.com/gallery/gIjCo
The fragments of a modern 155 mm HE shell will penetrate a 16 mm RHA plate with a fragment density of 1.5 fragments/square meter from a distance of 7 meters.

The rule of thumb a wargaming buddy of mine used to apply was that 1lb of HE shell weight wrecks 1 ton of tank. To determine if a given HE shell wrecks a given tank, you compare pounds' weight of the shell to tons' weight of the tank.

However, not all caliber shells had the same amount HE filler. The same caliber HE content could vary 50%-70%.

Dumb artillery against tanks: imgur.com/gallery/gIjCo
The fragments of a modern 155 mm HE shell will penetrate a 16 mm RHA plate with a fragment density of 1.5 fragments/square meter from a distance of 7 meters.

The rule of thumb a wargaming buddy of mine used to apply was that 1lb of HE shell weight wrecks 1 ton of tank. To determine if a given HE shell wrecks a given tank, you compare pounds' weight of the shell to tons' weight of the tank.

However, not all caliber shells had the same amount HE filler. The same caliber HE content could vary 50%-70%.

The HEAT penetration sound right.

Wolfhag

1.5 – 2.5 X the diameter of the HEAT round for WWII

That's a little optimistic. It's more like 1-1.5.

And then again … IIRC correctly it was in Death Traps where there was an anecdote about a German 150mm shell that hit a Sherman. Didn't penetrate the armor… it just split the armor in half and went through the tank. Similar accounts of Su-152 not pentratrating armor of German Big Cat tanks… they just jammed or blew off the turrets. US Tankers would rapid fire HE at German tanks … not pentrating the armor or knocking them out … but causing enough ancillary damage to make them withdraw. I had a friend who trained tankers on the M1 and went to war with them … he told me their biggest fear was not penetration or RPGs (What can penetrate an M1?) but rather the lowly mortars landing a round on the turret top or engine deck was really hazardous to the TCs health when unbuttoned. Decapitated TC = no penetration but your tank winds up operating at something less than peak efficiency while the crew mops up the remains.

Real life … unlike Wargaming… is not all about the "penetration". Cheers!

@ Wolfhag

Fair point about differential shell size, but that's why it was a rule of thumb. And of course in most games, there were normally only one or two weapons and targets on the table close enough that you needed to know the shell and tank weight accurately. If you were doing eastern front 1943, you probably had SU152, whose 100lb shell wrecked anything it hit.

If you fired 100mm HE against a Jagdpanzer IV then it's more finely balanced. I'd expect the shell to weigh (4^3/6^3) x 100 = roughly 30lbs. You'd then need to know whether the target weighed more or less than 30 tons. It's just under so this would be an edge case, but they are rare.

The 25pdr versus Churchill experiment sounds about like I'd expect. Churchills weigh more than 25 tons :-)

No doubt a large HE round could do some serious damage to most AFVs. In many cases KO'ing the target.

Real life … unlike Wargaming… is not all about the "penetration". Cheers!

Bingo !

Yes, my wife mentioned something similar. I never knew she was interested in tank warfare. Live and learn

On the Tank Archives blog there is an interesting post about using Russian 76mm HE as improvised AT rounds. Essentially the fuse was disabled.

Capable of knocking out all German light and medium tanks at ranges up to 1000m, according to the Russians.

Soviet 152mm guns didn't really need an AT round as the sheer mass of the shell was sufficient to demolish a Tiger, same for the longer barrelled 122.

Real life … unlike Wargaming… is not all about the "penetration". Cheers!

But in my case it last happened almost as long ago.

On the Tank Archives blog there is an interesting post about using Russian 76mm HE as improvised AT rounds. Essentially the fuse was disabled.

There was another one recently. The date was early war as there was an AP shell shortage going on.

Soviet 152mm guns didn't really need an AT round as the sheer mass of the shell was sufficient to demolish a Tiger

Didn't the Soviets have a bunker-busting anti-concrete shell (G-530?) that they used as AP? Or did until they realized the HE round was just as capable of getting a kill?

For penetration of HE rounds, I had been using as a rule of thumb 1/3 of the diameter of the round. For damage, I've been using the shells weight in kg as a damage modifier plus a small addition if it had a small HE charge.

I model the blast damage based on HE filler weight, not shells size. That makes the US 75 HE much better than other rounds.

If a 152mm HE round hits a tank I don't think you need to worry about penetration but then there are claims of Tigers surviving hits from them.

He is the excerpt Mobius mentioned:

I think I'll be going with the 75 HE penetration 50mm at 100m. We want to model some way that multiple 75 HE rounds would damage or jam the turret of a Tiger or Panther. We model the Panther mantlet shot trap with AP or HE burst causing spall damage through the hull roof. One playtester claimed a 75 HE with a point detonating fuse hitting the turret front of a Tiger II and mantlet of the Tiger I could have the same effect on the hull roof too. Looking at their profile a burst on the mantlet/turret front would affect the hull roof and hatches. Are there any examples of that actually happening.

Wolfhag

Didn't the Soviets have a bunker-busting anti-concrete shell (G-530?) that they used as AP? Or did until they realized the HE round was just as capable of getting a kill?

They had Naval semi-armored and anti-concrete shells. The guy at Tank Archives was saying at the battle of Kursk only HE was used by the Russian 152mm guns. I couldn't find official records of when the pointy AP BR-540 entered service. Let alone the blunt improved BR-540B AP.

Again, a 152mm HE shell would do a lot of damage to most German AFVs, regardless …

Found this on my hard drive. It is an excerpt from an old yahoogroups discussion in the 90's, when a lot of old-timers with hands-on experience were still alive and posting. I saved a fair amount of this stuff for reference.

FWIW.

"HEAT ammunition that fails to penetrate, will still explode. Small HEAT rounds have about the same effect as a hand grenade, and can damage optics or set fuel containers alight. Larger HEAT rounds might blow a wheel off. High explosive rounds can blow parts off a tank, or even "strip it" of all attachments. Some targets have HE pockets, which are areas which trap the HE, and increase its effect: look at the lower mantlet of a Panther, or the turret bustles on many post-war tanks. A 25 pounder round hitting such a pocket can knock a turret back, or even throw it into the air. In general, 30mm of armour is enough to keep out any HE
round, but their have been exceptions. Soviet 122mm HE hitting the front glacis of a Tiger II blew a 30cm diameter hole in it, due to the very poor armour quality. Against thin armour (less than 20mm typically), most field guns (about 75mm) used normal HE against light tanks with good effect.

HESH ammunition is similar to HE, but more deadly. The explosion is intimate with the tank armour, so more of the explosive gets behind the wheels, or into any gaps in the armoured envelope. I don't mean flaws in the armour, but gaps such as at the turret ring, or around a gun mantlet.
Finally, there is the matter of disruptive attack. Their isn't much agreement over exactly what a disruptive attack is, but I think Richard Simkin has about the best definition. This generally relates to shock-loading on the target. Let's look at some examples. A large HE round might not be able to penetrate the armour it hits, but the shock
is so great that the weld joint or rivets are broken, and the target bursts apart. There was an example in WWII of a Tiger II hit by an ISU-152: it didn't penetrate, but it did strip the gears on the final drive so the Tiger couldn't move. Painted interiors on tanks have caused many casualties, when non-penetrating rounds have forced flakes
to come off at high velocity, causing cuts or eye-damage. In WWII, Germany found that too many wounds were caused by equipment attached to the sides of hull and turret being blown off, so spacers were used in an attempt to reduce this effect. Brittle armour, particularly when face-hardened, caused problems with minor scabbing, which could wound crew, puncture fuel tanks or cartridge cases."

B

. Soviet 122mm HE hitting the front glacis of a Tiger II blew a 30cm diameter hole in it, due to the very poor armour quality.

Good luck finding evidence of that.
Here is a Soviet firing test.
link

With the bigger calibre artillery shells, it is mainly about the energy transferred (mass x velocity and all that).

The German K18 100mm gun was an effective improvised AT gun as it ha a far higher muzzle velocity than its 105mm and 150mm howitzer pals.

Similarly I wouldn't confuse the effect of a Russian 122mm howitzer with that of a long barrelled 122mm Corps Gun.

Bear in mind the 152mm gun (or long US 155) was like a direct hit from a light cruiser.

The Parola Tank Museum had a display of a T-55 turret that was hit by various shells. A 100mm HE hit on the rear part of about 60mm armor made cracks on the inside and a dent.

Not a Tiger II but maybe about the same effect.

Wolfhag

Looks like a kill to me !

I have been reading "The Day of the Panzer: A story of American Heroism and sacrifice in Southern France" by Jeff Danby. It is an attempt to trace the actions by his grandfather, 1st Lt Edgar Danby as a replacement Sherman platoon commander in Southern France.

He talks at one point about the Sherman crews replenishing their ammunition and adjusting the fuses on the new HE rounds. In his footnotes, as a result of several interviews he did with veterans, he has this comment:
"The rounds consisted of HE, AP (or "shot") and "Smoke." The most common was HE. The crews preferred to adjust the fuse from the "Super Quick" factory setting to the highest "Delay" possible. The change represented only a fraction of a second in timing, but was the difference between an HE round exploding outside a vehicle or structure on impact or penetrating the object and going off inside with more destructive effects. Most battlefield situations called for delayed explosion"

Give original post started with 75mm Sherman thought some would find these observations interesting. And the book is very good and highly recommended

Not a Tiger II but maybe about the same effect.

I think that's from an AP round.

I think that's from an AP round.

It is. The caption reads "Glacis of a Panther tank struck by 152mm armour-piercing round. The hole measures 360 x 470mm. The round ricocheted. Range to target 1200m."

Did I read that correctly? It ricocheted and still punched a whole in the armor?

Judging from the "postbox" driver slit, the target Panther was an early Ausf D model – perhaps a souvenir from Kursk. IIRC, this model featured a face-hardened glacis which was replaced by RHA in the later Ausf A.

The 152mm AP = a huge overmatch versus the front glacis plate. If one expands the photo image, it appears that the armor suffered a brittleness failure: the hole is very large and appears to have been broken out rather than plastically deformed; there is also a large concentric crack in the plate passing all the way around the hole; there is also evidence of what appears to be a piece broken out at the join between the upper and lower glacis plates.

Evidence of very great shock effect IMO.

B

In addition the Russians didn't have a good ballistic model for their 152mm AP shell. In one document they use the same model for the aerodynamic HE shell as the ogive AP shell. Thus the 1200m striking is more like 600m.

Interestingly, the British 4.5-inch and 5.5-inch medium artillery pieces did not have an AP round at all. They did, however, have an anti-tank drill and even aimed over open-sights in practice anti-tank shoots.

The drill was simply to fire an H.E. round with the fused removed. The result was big, inert moving lump which was guaranteed to rip the turret off of any tank which it hit. My late father heard of an incident in Normandy where 5.5s fired over open-sights at German tanks on a hilltop and, yes, the turrets were ripped off. It worked.

I live near Titchwell RSPB (Royal Society for the Protection of Birds) in Norfolk, UK, and on the beach are two tank wrecks, two abandoned Covenanters. By reputation they were ex-range targets. Recent tidal wash has removed some sand from around them and exposed more of the vehicles including hits on both chassis.

Most interestingly, one Covenanter has a massive deformation in what looks like 30/40mm plate which could only have been caused by a medium gun. There is no piercing. Coincidentally, British medium guns were trained at Titchwell in anti-tank fire prior to D-Day. I will try to dig out some photos of the two wrecks and the exposed damage and put them up.

Barry

Did I read that correctly? It ricocheted and still punched a whole in the armor?

Yup. That's what it says. 152mm AP fired from 1200m, it smashed a gert hole in the armour and ed off into the ulu!

So if you remove the fuse do you still get an impact explosion at some later than normal point or do you just turn your HE into roundshot?

I'm not surprised the 5.5" took the turret off tanks. Given a 6" round usually weighed 100lbs, a 5.5" arithmetically must have weighed about 75 or 80lbs. That's gotta hurt.

@4th Cuirassier:
You turn it into a solid shot. A very big solid shot.

I have put all the Titchwell tank shots here:
link

All shots are thumbnails and all open up larger when double-clicked.

The deformed plate is this one:
link

The plating is about 30 to 40mm thick and has been deflected downwards by about two inches or 50mm, maybe more. You would require an enormous impact to do that bearing in mind that the tanks were complete when they were hit.

B

@ Warspite – interesting, thanks.

@ Wolfhag – you mentioned earlier that more HE in the shell made for more bang in the case of the US 75mm. I'm not disagreeing with you here because I don't know, but does this necessarily follow? I thought that a factor was also the thickness of the casing. The thicker it is, the more pressure builds up inside it before it bursts, and so the bigger the resulting explosion. This is why the Mills bomb went off more violently and threw fragments further than the German stick hand grenade, even though the Mills had the same or less explosive in it. No?

One of the issues as I understand it is getting a Hit. A HE round from an anti-Tank/Tank gun is probably viable as its is probably a relatively high velocity round whose ballistics are close to an anti-tank round so has similar accuracy.
However field guns are lower velocity (higher yield)and so relatively low accuracy so hitting a moving tank over direct sights is hard I was told by an ex-artillery man from the cold war era.

HE shells didn't have tracers so getting hits from long range is harder as it is more difficult to correct on the fall of shot.

One thing good about the US WP shell is that it had a tracer.

Early German 75mm HL HEAT shell was made from a HE casing and did not have a tracer. Later HL/A..HL/C did have tracers.

4th Cuirassier,
The Stielhandgranate primarily relied on a concussion blast effect, its thin metal container creating little fragmentation compared with many grenades of the time, such as the Mills Bomb and the French F1 Grenade, the later World War II American Mk 2 grenade, and the Soviet F1 Grenade. This is normally called an "Offensive Grenade" to be used when assaulting. The concussion effects the defender to suppress him and the attacker does not have to worry about being hit by fragments. The German had 6 oz of TNT and the Mills Bomb 2.5 oz of Baritol.

The Germans made a Splitterring that was a simple cylindrical steel sleeve, with either a smooth or serrated surface, clipped in place over the head of a stick grenade with three keepers around the base, and secured with a tension ring. This easy modification allowed a single type of grenade to be manufactured and carried by soldiers, whereas other nations often produced separate types of concussion and anti-personnel grenades.

There appears to be a balance of HE filler and shell casing/fragmentation. At Tarawa the Marines in open top Amtracks had 75mm HE rounds fired at them with a times fuse to explode over them. However, the Marines described the effect as "being hit with hot sand" and did not cause causalities. Evidently the rounds had too strong of a filler and too light of a casing.

High velocity shells require a thicker shell wall/casing to withstand the shock of firing so less HE filler. If the casing is too thick it breaks into fewer and larger fragments that do not give good coverage. This is why howitzer and mortars have the highest % of HE filler. I think the HE shell for US 75 on the Sherman hit the "sweet spot" regarding HE filler and fragmentation casing. Not all HE filler is equal either. I think RDX is 20% more effective than TNT.

filler

fragmentation

Wolfhag

Here is a Panther D hit by a 152mm HE

Wolfhag

Jaysus! That's gotta chafe! Looks like it penetrated the armour and then exploded inside the turret. I somehow doubt anyone got out.

Yeah … I think that's a total write off …

The soviets did a lot of research on HE shells effectiveness against armour and came to the conclusion that a 122/152 HE round could knock a tank out if it hit it correctly, the story is blowing a turret off, which would have been rare, but more likely affecting its tracks or even knocking the tank over.
As for the Panther, some late war Panther's had poor quality armour, which could shatter. If the picture was knocked out by a single 152mm HE round this could be caused by this type of poor quality armour. This also looks like there was a fire, so some of the metal may have burned, but I do see shatter evidence. It could also have blown up from the inside.
However the big issue with HE round is their low velocity, accuracy beyond 1 second of flight was low due to gravity. Still if you were within 300m and could hit the flank of a tank, it may have proven very effective.
Also note that late in the war the Soviets issues their SU-152's with APHE rounds. This could be an APHE round.

In the Pacific US 37mm. guns sometimes used the M.63 pattern HE shell against Japanese AFV's. The M.63 has a base mounted delay fuse for use against fortifications & structures, so performs much like an APHE or CPHE shell.

There is a possibility that the Sherman 75mm. may have shot a M.63 pattern HE "anti-pillbox" shell at the Panzer IV. Another possibility is that the fuse had been removed or disabled on a conventional 75mm. HE shell before firing.

I have a 1930's US range test here somewhere for the 37mm. L.53 & 75mm. L.36.3 field gun M.63 HE shell versus armour. I'll have to dig it out. It was regarded as a multi-purpose shell in the 1930's.

The British 5.5" howitzer could be fired at AFV's by replacing the fuse on the HE with the provided Hadfield steel AP tip, rendering the shell innert, despite the Torpex filling remaining.

I've heard of tankers & field artillery personnel removing the nose fuses from HE shells to make them suitable for use against AFV's. HE shell carcasses are not as strong as AP shot & shell, but it's still a mass travelling at considerable speed impacting armour.

Unfortunately even the meticulous Germans never conducted range tests on shooting unfused HE shells at armoured targets.

In the Pacific US 37mm. guns sometimes used the M.63 pattern HE shell against Japanese AFV's. The M.63 has a base mounted delay fuse for use against fortifications & structures, so performs much like an APHE or CPHE shell.

There is a possibility that the Sherman 75mm. may have shot a M.63 pattern HE "anti-pillbox" shell at the Panzer IV. Another possibility is that the fuse had been removed or disabled on a conventional 75mm. HE shell before firing.

I have a 1930's US range test here somewhere for the 37mm. L.53 & 75mm. L.36.3 field gun M.63 HE shell versus armour. I'll have to dig it out. It was regarded as a multi-purpose shell in the 1930's.

The British 5.5" howitzer could be fired at AFV's by replacing the fuse on the HE with the provided Hadfield steel AP tip, rendering the shell innert, despite the Torpex filling remaining.

I've heard of tankers & field artillery personnel removing the nose fuses from HE shells to make them suitable for use against AFV's. HE shell carcasses are not as strong as AP shot & shell, but it's still a mass travelling at considerable speed impacting armour.

Unfortunately even the meticulous Germans never conducted range tests on shooting unfused HE shells at armoured targets.

In addition to the question of armor penetration, what about the concussion affects of the explosion?