Panzergranate 44 - German APFSDS

[schwarzpanzer]

Hi Shortround,

Thanks for the HE info. In a tank, HE is used for 2 different things:

1. Attacking targets out in the open - such as ATGs, infantry etc. This often means not a direct hit, often relies on frag blast effect. I expect this could disable tank tracks? (if very close - which is possible on a tank @ long range, as are even direct hits).

2. Attacking buildings and bunkers etc. Now this is where I fall down. As I see it though, the explosive detonates on contact and rips the target apart - I would expect the same to happen to metal plates, if they were brittle or thin enough, or badly joined. I know about HESH, but I would expect HE to work slightly similar? (only with less velocity on the 'scab').

BTW, apparently Soviet HE shells were very simple and effective - having a 2-positon 'switch' - one for blast (number 1., above) and one for contact (2.).

If you use a big enough shell and detonate it close enough you may get spalling effect.

Thats what I'm pretty much meaning. It depends a lot on the exact shell (size quality) vs the exact armour (thickness, quality cconstruction) though. I'm only talking of direct hits (unless for track jamming).

True the thickness and quality of the armor will have some effect but how thick was the armor of the T-34 prototype that was supposed to "shell proof" against 75-77mm shells?

45mm sloped @ 60 degrees. Aprox 60-70mm @ round IIRC (turret front). Turret sides rear were somewhere inbetween (all aprox equal). 'Shell-proof' was actually referring to 76.2mm Soviet AP shells - not just artillery fragments (which the pre - shell-proof BT could keep out). T-34 prototypes were good quality though, but unreliable - the exact opposite of production versions!

I am sure that by searching hard enough you can come up with freak happenings for a lot of weapons. Most of the discussions may be post war by war gamers of the "Timmy, the power gamer" type. I am not sure you could even fire Karl-Gerat at zero degrees elevation. Loading rates, traverse, and low velocity mean these would be short range, limited, one shot wonders at best. And just when does the rocket on the 380mm Stormtiger kick in? after it has left the muzzle? does wonders for accuracy. doesn't matter against large building or group of trucks or at 200-300 yds but for a long range weapon?

lol. The Sturmtiger thing actually happened - apparently 12 Shermans were destroyed in a single hit IIRC. Of course though, this was, as you say, a freak happening. Probably in desperation, or set up with the help of an observer, pure luck, skill or pure accident - but I used it to hopefully illustrate that a smaller, higher velocity weapon, such as a SiG-33 could easily destroy a single Sherman with a direct hit?

I'm not sure Zero Elevation was what was suggested? - but then, it was Krupp, so who knows?

Rommel made the same point you did, to Hitler, because of what Krupp said. Probably Krupp was a gigantomaniac loon, but then again?... I think it wasnt so much Hitler that was the loon, but his designers (Henschel, Porsche, MAN Krupp all seemed to have produced no end of idiotic ideas).


Of course HE isnt ideal for Anti-tank use, but if its all thats available... I'm trying to find out just how useful that was. BTW the 1st tanks to be destroyed (in WW1) were very likely destroyed by HE shells.

I was thinking that, as the KwK 37 had a high trajectory, that the shells would not hit it flat-on. I wondered whether I shouldve put 'comfortably' but IIRC it was the best option. There was also the turret to consider. The Matilda was a small target though (but slow) and the KwK 37 hard to get hits with - especially early war, as training with this round had been sabotaged by infighting. It did score hits on the fast-moving, low-slung T-34 though (some of them by Michael Wittman). Once it hit though, the cramped confines of the Matilda would have made the effets devastating. True that variations in rounds would also have hindered though - but was it really that bad?

I have heard of HEAT rounds skidding/ricocheting, though this has been something I'm always researching (no answer yet!). I wonder if this is why the Bazooka had problems with the T-34 in Korea?


hartmann, tomo and I are discssing the PPS round, I thought you were too, sorry. It seems to have been developed for anti-armour performance though. What problems btw? ?(though I am guessing they may have been menioned already).

The AT and Tank guns that used APDS got about a 30-40% increase in penetration and had to pay the price of Tungsten carbide use for that. Maybe you can fire a standard 75mm APCBC projectile out of a 105 barrel by using sabots but is it going to be any faster/better than a normal 75mm AT gun? And you have the bigger size/weight of the 105.

I meant the lighter APCR shell would have a higher MV? Your idea for a 75mm sub-projectile is a good one though ( would remove the need for tungsten), but IIRC the APCR penetrator wouldve been more like 40mm. Also, at this point, I'm not sure APC 75mm ammo was available? Again, this is a round for desperation - until the PaK 40 comes online in sufficient numbers ( for desperate self-defense).

I think you are.

No I am not!! (though I do tend to lump the two together, as they are near as damnit).

and the plates could crack right across

Wouldnt this make penetration easier? - though I suppose it would spread the load...

There are many advantages to a Cap, in addition to your points: It reduces ricocheting (esp. off sloped armour), and acts as a 'damper' or 'cushion'.

It stressed a local point on the armor and weakened it and tended to push material aside rather than trying to shear out a plug like a high speed flat faced punch.

I think this may be where you may be getting confused. When vs tank armour, the projectile is better going into the interior (though the 'plug' will add to the damage). I suppose on ship armour it is the most important part?

(around 2000fps ?)

Yup. IIRC I've heard 2600fps, but 2-3k fps is a good base. As I like to over-compensate, I like to work with 2k fps. 1250 fps is enough for steel LRPs though.

the body would remain a bit softer but tougher (bend a bit before breaking).

This point you mention though apparently have some advantages when vs angled plates, but I'm not so sure...

An HE shell body breaking up under the stress of impact and spilling it's load isn't really the same thing.

Even solid shots can break up though - /HE content just makes this worse. I think even 'shatter' and 'blunting' are 2 different things though - making 3 different effects under the 'shatter' umbrella.

that device has 42 oz of TNT or explosive in it. or almost 1.2 kg. How much in a 105 shell?

No idea. - but I wouldve thought more than 5 or 6 potato mashers lumped together?

Some accounts speak of trying to throw/place the charge on the engine deck/grates which are hardly 60mm thick.

Thats true, but I think it was just usually lobbed at the side armour? 45mm of vertical, brittle armour there, so?... It would at least immobilise it? Maybe even cause mechanical shock (stopping the engine/trans?).

a mighty near miss. I think a 150-155 had to land under 10 yds away to have reasonable chance of disabling a tank and the 105s carried 25-33% of the explosive of a 150-155mm?

This would be easily achievable on a StuH (more likely a diret hit). A Wespe or LFH 18 though?... I think it would be possible?

Well, you have to start somewhere and a look at the drawings shows why it wasn't very good. In 1938-1940 a lot of people knew the general principal which dated back to before 1900. It was turning this laboratory trick into a usable weapon that took a few years. The fact it wasn't issued in numbers and that the version which replaced it was only marginally better than the AP shot indicates the first version wasn't very good.

I remember the guy who invented the Bazooka got totally laughed at - but he was driven, and made a good presentation... KE was seen as the way to go. The Soviets were the only ones who ever really treated ( treat) HEAT as a viable ATG round. Perhaps its just National doctrine more than anything else? Of course, I believe the KwK 40 to have been a better weapon than the KwK 37 - but the KwK 40 wasnt available then... Again, its trying to make the most of what the Germans had at the time (KwK 37, LFH 18 later PaK 38 - but no KwK/PaK 40s; then later150mms, but no105/128mm ATGs). These methods were used though, which backs up my arguement, but what I want to know is, how well? Of course, you are right in saying that they arent ideal - but thats not the point I'm trying to debate.

Not according to one source.

Which one is that please?

I actually have found 105mm HEAT penetration figures, these are: 103, 116 128mm - for A, B C types.

The short 75mm's, from the same source, are: 90, 96 128mm. Odd that the last 2 should be the same... (though the 75mm was considerd to need it more).

The longer 75mms also fired HEAT, but data for that doesnt come easy to had ( would be from a different source).

The source given is notoriously bad for HEAT data though, I should add, but it gives a rough view.

Still, it may be that 105mm HEAT performance was not much above the 75mms - but that would likely change, if the 105mm was developed to the same extent as the 75mm.

BTW, from that source, the 150mm 'A' shell is given as 206mm. ('C' shell was estimated on here as being 230mm, IIRC?).

 

[schwarzpanzer]

Hi Shortround (Part 2),

Lousy penetration. about 2 in or 50mm and you needed a 90 degree impact angle to get that.

More than enough to deal with a Panzer though? - except later PzIIIs turret glacis IVs glacis'.

I think it was OK, even @ that figure. The source above gives 89mm - enough to deal with a Tiger! (but horribly wrong, I take it?).

Once you got through the 30mm armor of a MK III or IV with an angled impact did it really have much more effect inside the tank than an anti-tank rifle bullet

I think anything was better than the Boyes? (Though in Japan its greater accuracy might make it better?).


I hold 'shatter' as distinct from 'blunting'. Impact velocity is a big part of it, yes, but apparently overmatch and you really reduce the chances of this happening (maybe even nullify it?). Of course, I know that often it is not a problem (or was in WW2 even) - but I like to factor it in anyway. I think the lack of quality armour in WW2 is what allowed designers to get away with not factoring it in. Then again though, no tank (apart from the Tiger) really had armour that could usefully exploit this (exept for some PzIIIs maybe IVs).

Penetration in spite of shatter can happen - but I wouldnt like to rely on this, if I was a designer (?).

At long range the dispersion is greater and more shells are going to be needed to get hits. The longer the range the more shells needed per hit. so how many shells per hit or tank knocked out is acceptable? also consider that for towed AT or open topped vehicles the longer the engagement goes on the greater the likelihood of the enemy artillery joining in. Depends on your HE shells, high explosives may be in shorter supply than steel, fuses aren't cheap and good HE shells require high quality steel. Mediocre ones don't.

I suppos it depends on the ranges, the ranges I propose are 1-2km, using direct fire (possible?). Indirect fire is something different altogether. I may create an 'Indirect Arty AT Fire' Thread later as I dont want this one to become bogged down with it ( its something I will find hard to understand - though hits on roof armour are guaranteed kills?).

Thank for the HE expenses info. I suppose thats another compromise.

Wrought Iron is still pretty brittle though? - but I suppose it depends on the quality? Why didnt they use malleable steel instead? (low carbon IIRC). I suppose its similar to a Katana? I know a plumber, I'll ask - though its all copper, lead or plastic think - no iron? I was actually a plumbers mate, and had hell on with a lead pipe once (was concreted in!).

Layered armour was tried in WW2 - on the Kleiner Tiger (baby KT). Katana-like armour got into mass production, on the Pz III apparently, Tiger.

I am not sure but at the time it was considered that spinning the projectile (rifling) cut the ability of a given shaped charge design in half.

Thats probably, right, and a good way to remember it, thankyou. IIRC, I read that the RPG spun - can't be right?? - will need to check (thought it seemed wrong @ the time - which is probably why its stuck in my head).

A source gives the HEAT penetration of the 15cm howitzer shell as 160mm so it should have the ability. But in WW II there was a fusing problem and HEAT shells wouldn't function properly at high impact velocities. In some cases the heat shells were fired at less than full charge even by howitzers. So you have the ability to penetrate IF you hit but a lower chance to hit at ranges over 500meters and the chances get worse the longer the range.

Sorry, I meant LFH 18 (105mm). HEAT shells are never meant to strike @ high velocities - a gunner who knows what hes doing will not often use them above 500m.

I think the KwK 37 had a max range of 1,200m - maybe more with a very good gunner (even upto 2km maybe). Still, this is mostly using 'bracketing' techniques though - lots of ammo expenditure. I would expect the LFH 18 to do better though?

Not only were some later Japanese tanks more heavily armored (Type 97) but single penetrations of vehicles by even 12.7-14.5mm bullets doesn't lead to destruction in most cases.

Thanks for the Indian HEAT info. Grants used 75mm AP shells against bunkers - so I think this would be their intended use (though AT work would be interesting, but pointless - unless vs German vehicles, which you said didnt happen - pity!). I would expect a Boyes to keep shooting (but its recil was terrible). It was a really poor weapon, but still useful here (an AT backwater). Jap tanks were cramped though - riveted, which would help. They were so cramped that they required padding! (but were thus a small target - no problem for the accurate Boyes?).

Doesn't it also degrade HE performance though?

Why should it? unless you are trying to shove HE shells through thick armor.

Doesnt what, sorry? (I'll have to look that up!). I think I meant 'Can HE shells withstand greater impact velocities than HEAT can?'

I am not denying that this ping-pong effect happened at times but It is my opinion that there are too many variables (range, different targets, different impact angles on the same target) to try to design it into a gun/ammo combination. If somebody can show me a design breif that say sthis was a requirement then OK but until then....

It is the only way certain projectiles can work (the ones I mentioned). I've seen reports of damage caused to a Panther by a Bazooka that showed this, also pretty much every report I've come across. I think your 'plug' idea is also a good one, but I would consider this secondary to the 'ping-pong' (though maybe about equal now). The other effect would be incandescent properties. BTW, I wonder if a succesful APHE detonation would actually reduce the incendiary effects...

the 1,000yds thing is very Dependant on the year and theater. Early battles in the Dessert often meant holding fire to 600yds or so and the 25pdrs when used as AT guns often held their fire to 400yds or less.

A very good point. 400-600yds is scary! I read though, that if the Pont Du Fahs 6pdr gunners had've opened fire at ranges below what they did (aprox 500m) they would not have suceeded. I found an awesome article on this ( shatter-gap), that I posted here in about 2006, but I cant find it for love nor money! (deleted?).

You seem obsessed with this shatter thing.

Ive explained abve, but guilty as charged.

Yes it did happen, more to certain gun/projectile vs enemy tank combinations than others. Some guns never suffered from it. The British 2pdr had a problem with it but that was also because of the face hardened plates the Germans were using on the MK IIIs and MK IVs. Earlier introduction of a capped projectile would have gone a long way in solving that problem.

True. The PaK 36s rounds were APCBC though - but I suppose you design to defeat your own armour really (strange, but true!). The lack of /HE in the 2pdr allowed much better penetration than the German 37mm (pity about the shatter/quality). Later spaced armour on the PzIII IV disabled Caps btw... - could tumble AP rounds too.

As far as the caps deforming on penetration, they would have been stripped away having done their job. However the cap action was discovered back before 1900 when a target plate was installed backwards on a test range and a projectile went through more armor than it was figured to by entering the soft side first. So if your recapped projectile is trying to exit face hardened armor it may not need it's own cap.

Thats a good point. However, on spaced armour (esp. on the PzIII) this would not be the case.

If it had tumbled though, I reckon it wouldnt exit (very likely to happen).

Again, do you have any proof of this?

There is no other way the 'K' bullet could work? - the 'plug' would only be a 8x8mm disk (unless it was good quality - in which case the armour would just tear, with no plug?). When inside a tank, a ping-ponging round is going to be either very damaging, or at least very scary. Especially with multiple hits. I think I've seen a demo vid of it happening - if I stumble across it, I'll post it. ANy more ping-pong info I happen upon, Ill also post.

Post war British APDS ( they didn't really design much post war shot) depended on blowing a hole through the armor. Given the thickness of the targets (no more 15-30mm tin cans) there would be enough secondary projectiles blown out of the armor to cover the question of leathiality

- but it wouldnt start a fire?... Youd need the incandescent penetrator for that. If the armour 'tore' - then youd get no 'plug'?.

Front line 88mm AA guns are targets for normal artillery. Once they fire at aircraft their positions are reveled and it would take hours to shift them. This gives the opposing artillery plenty of time to shell them.

Thanks for the info. So you're in agreement then? Wonder if we've any AA Arty fans on here? Rommel was often hated by the Luftwaffe for stealing their guns for 'improper use'. It seems he was 100% right though? What about the 3.7in 'Morale' guns in Britain? Still, AAA was apparently very useful against V1s.

 

[schwarzpanzer]

Hi Shortround (Part 3 - sorry, almost missed this one),

Quote:
Originally Posted by schwarzpanzer (Part 3).Arty HE fire doesn't depend on sights so much though? – rather plotting corrections from an observer?

Sorry, it would appear your answer to this has been lost.

loading 40-50kg projectiles vs 25kg projectiles? book figures for towed howitzers list same rate of fire 3-4 per minute but that is with a large gun crew.

Thanks, but the German 88mm had a higher RoF than a 7.62mm NATO rifle bullet! (apparently in certain circumstances).

The later D-25T improved the RoF much further. Do you think those Wikipedia figures are wrong? How many loaders for the towed versions?

Yes it was, but this needs a thread of it's own.

I heard that from a guy whos relative fought in the war. For e.g. DYK that the T-55s had night vision - but the Centurions didnt? The T-55 was later upgraded by the Israelis, but the base models were better too. They were too small for Israeli crews though.

It depends on original design. If you are trying to fit synchros into an existing gear case you have to make the gears thinner and less strong.

I have experience with 2 boxes - the 1st was designed in the 1950s (or even earlier) so OK, but the seccond was more like the 80s. "Shouldn't" and "much"?... Would dog-engagement (?) be OK for a tank? Do Preselectors use Synchro? Is Synchro redundant in a Preselector? I suppose Spur gears will create a constant whine though - but IIRC bigger gears cause less, rather than more noise? Plus, you have that bulkhead... (though not in the Panzers). Perhaps Helical gears on final drives only? Spur gears are also much easier to manufacture? (though once setup, it wouldnt cause much difference - for the production levels wanted?).

If you are designing from scratch and transmission case size is unrestricted there shouldn't be much problem.

I think a smaller transmisson is better - to reduce external vehicle dimensions /or interior room?

With low rpm engines you have less over lap of gears. I drive a 34 ton fire truck with a 450hp engine and a 4 speed automatic. While much faster than a tank I think the same principles appliy. Max engine speed is 2200rpm. While it will do 55mph on the level it often is down to 30mph on hill, max rpm in second gear, 1st is good for 15mph. if it shifts to 3rd gear on the hill it is below it's torque and power peaks and can't rev up. More gears mean more options and better mobility in less than flat smooth conditions.

You actually have a fire engine? Swank! Theres a joke based around that, wont say it, as you may not get it (but last time I used it on an AMerican, he understood). Anyway, back to seriousnessness You're truck will have a lower rolling resistance (about the same that the soles of your feet have). The power and rpm levels are very similar though, and would be useful for comparisons. BTW, do you have the torque levels, hp levels of your engine - @ rpms? It would be very useful for these discussions!8) The rolling resistance of tracks is much higher than your tyres - on one hand it hurts top speed (which is why your truck ha higher top speed), yet when it comes to hills, that rollin resistance is lessened, equated into sheer inertia-beating traction, something your truck could never come near - if it had more power, it would just spin its wheels. Of course, momentum is desireable in a tank too (but less vital). There is a nasty little trick that yuppies like to do to vehicles such a yours in the UK.

Too many gears can cause headaches too, apparently, 3rd gear is the most often used in a tank, but I would say 4 gears is enough? I wonder how many the M18 Hellcat had?...

Power spreads are a different matter...

Other things that can affect tank speed are the rolling resistance of the track itself, some designs had twice the rolling resistance of others and track tension. slack track having less rolling resistance. But each of these choices have there down sides too

True, but this is not something I often have had to bother calculating (though I can, really should've). What are the plusses minuses on tracks btw? Do you happen to have data on calculating tank rolling resistances? (I suppose I could figure it out myself though - I might have to make a spreadsheet!).

Do you mean rolling resistance vs grip ground pressure?

 

[Shortround6]

1. Attacking targets out in the open - such as ATGs, infantry etc. This often means not a direct hit, often relies on frag blast effect. I expect this could disable tank tracks? (if very close - which is possible on a tank @ long range, as are even direct hits).

For those targets close was good enough, a direct may have been a bonus. But for disabling tanks you need a lot more luck, and effect on tracks is related to the size of the shell and the size of the track. It's a lot easier to break the track or break the road wheel of a Bren carrier that a Tiger tank

2. Attacking buildings and bunkers etc. Now this is where I fall down. As I see it though, the explosive detonates on contact and rips the target apart - I would expect the same to happen to metal plates, if they were brittle or thin enough, or badly joined. I know about HESH, but I would expect HE to work slightly similar? (only with less velocity on the 'scab').

HE worked better if it could penetrate, even if only part way. Think of trying to blow a brick building up (or down) with just a few pounds of explosive. Explode it outside, a few feet from the building? Put it inside one of the rooms? or drill a hole in the wall and put explosive in the wall?

HE against tanks will not form scabs if there is any real distance (air space) from the explosion and the armor.

45mm sloped @ 60 degrees. Aprox 60-70mm @ round IIRC (turret front). Turret sides rear were somewhere inbetween (all aprox equal). 'Shell-proof' was actually referring to 76.2mm Soviet AP shells - not just artillery fragments (which the pre - shell-proof BT could keep out).

according to one book the 25mm armor of the A-20 prototype satisfied the 'Shell-proof' requirement.

- but I used it to hopefully illustrate that a smaller, higher velocity weapon, such as a SiG-33 could easily destroy a single Sherman with a direct hit?

that things COULD happen isn't in dispute. That such happenings are the basis for good vehicle design or possible tactics are.

Consider that the SiG-33 has a MV of 240M/s with max charge for the HE shell. This means about a 265 meter point blank range. Point blank range being the distance (given a suitable elevation) that the shell will neither pass over or hit below a normal tank sized target. A standard 75m Sherman has got a point blank range about 2 1/2 times further. A Sherman gunner could simply set his sight for about 500m meters or so and be fairly confident of a hit (somewhere on the enemy tank) out to around 680meters. aiming at a particular point on the tank takes a bit more refinement.
Our German gunner at 600 meters distance, if he misjudges the range by just 25 meters or so will either shoot over or under the Sherman ( under might not be so bad but lobbing the shell over the top isn't likely to throw the Sherman gunner off that much). Then the Sherman with it's much faster firing gun gets 2-3-4 "free shots" while the SiG -33 is being reloaded, or moves a hundred meters

Giving such guns AT ammunition in case of emergency is one thing. trying to use them as part of a planned anti-tank defense is a poor use of assets.

Of course HE isnt ideal for Anti-tank use, but if its all thats available... I'm trying to find out just how useful that was. BTW the 1st tanks to be destroyed (in WW1) were very likely destroyed by HE shells.

It 150mm howitzers are all that is available then the battle plan has gone seriously wrong and you are trying for a miracle solution of near biblical proportions to save it.
BTW the tanks in WW I were destroyed by HE shells but then the WW I tanks had armor of about 8-9mm in thickness and none too great a quality either. A dud HE shell could punch through it.

I was thinking that, as the KwK 37 had a high trajectory, that the shells would not hit it flat-on..... True that variations in rounds would also have hindered though - but was it really that bad?

The difference in trajectory can be amazing but the difference in hit angle isn't that great. one degree equals 5 ft at 100yds. so for a two degree change in impact in your favor your projectile would have had to be about 10 ft higher than the point of aim at a little less than 100 yds out. Now figure the target is not sitting on a billiard table but maybe siting on a bit of an angle itself and may not be facing you square. Armor penetration figures given in most tables are an average of 10 shots or so depending on nations test procedure.

I wonder if this is why the Bazooka had problems with the T-34 in Korea?

I don't know but consider that if the Bazooka had a proving ground figure of 120mm and hit a 45mm plate at 60 degrees it actually has to penetrate 90mm of armor by geometry. throw in a little skid and/or not hitting dead on in horizontal plane and the margin becomes even narrower. How much over penetration is needed to have a telling effect?

I meant the lighter APCR shell would have a higher MV? Your idea for a 75mm sub-projectile is a good one though ( would remove the need for tungsten), but IIRC the APCR penetrator wouldve been more like 40mm. Also, at this point, I'm not sure APC 75mm ammo was available? Again, this is a round for desperation - until the PaK 40 comes online in sufficient numbers ( for desperate self-defense).

If you have enough time to design, test, develop and manufacture trick ammo, shouldn't you have enough time to produce real anti-tank guns?
The full bore 10.5cm AP projectile was enough to handle everything but a Matilda (and there weren't that many of them) up until 1941.

No I am not!! (though I do tend to lump the two together, as they are near as damnit).

Even solid shots can break up though - /HE content just makes this worse. I think even 'shatter' and 'blunting' are 2 different things though - making 3 different effects under the 'shatter' umbrella.

To keep things straight, shatter is what happens when the hard point of the projectile shatters or breaks up on hitting the armor, blunting if you like because that is what happens. like trying use a blunt knife or dull drill. The shell body breaking up is different. The shell walls were not strong enough to withstand the compression forces (still moving rear of shell pushes the shell walls behind the rapidly stopping shell nose). It may be possible to have a broken shell body with a relatively intact nose.

No idea. - but I wouldve thought more than 5 or 6 potato mashers lumped together?

Thats true, but I think it was just usually lobbed at the side armour? 45mm of vertical, brittle armour there, so?... It would at least immobilise it? Maybe even cause mechanical shock (stopping the engine/trans).

German 10.5 howitzer shell had just over 48oz of explosive. The Grenade used a time fuse. Pulling the string out of the handle ignited a compound like the head of a match which in turn lite a burning fuse. timing was approximate, 4-6 seconds? timing your throw for impact detonation would require large amounts of luck. throwing too soon and the charge could bounce/ roll off and explode on the ground, throwing too late could mean "Hans" get caught in his own blast. Trying for the engine deck means it might not roll off or if placed there means "Hans" has 4-6 seconds to get away.

I remember the guy who invented the Bazooka got totally laughed at - but he was driven, and made a good presentation... KE was seen as the way to go. The Soviets were the only ones who ever really treated ( treat) HEAT as a viable ATG round. Perhaps its just National doctrine more than anything else? Of course, I believe the KwK 40 to have been a better weapon than the KwK 37 - but the KwK 40 wasnt available then... Again, its trying to make the most of what the Germans had at the time (KwK 37, LFH 18 later PaK 38 - but no KwK/PaK 40s; then later150mms, but no105/128mm ATGs). These methods were used though, which backs up my arguement, but what I want to know is, how well? Of course, you are right in saying that they arent ideal - but thats not the point I'm trying to debate.

Bazooka warhead was from a "rifle grenade" design for the .50 cal machine gun. Not very practical.
Russians use/d HEAT because for many years their guns/propellant wasn't up to western standards and they could not get the velocities of KE projectiles up to western levels for a given gun size. National doctrine?

Again, using your divisional, corp or army artillery as anti-tank guns in the front or even second lines of defense is a gross miss use of the asset. Most Armies didn't have enough of them to begin with (except maybe the Russians).
From a tactical standpoint they are large, difficult to dig in/emplace, almost immovable once combat starts, have low rates of fire and with their heavy barrels have difficulty tracking moving targets even if their carriage has enough traverse.

 

[Shortround6]

(Part 2),
More than enough to deal with a Panzer though? - except later PzIIIs turret glacis IVs glacis'.
I think anything was better than the Boyes? (Though in Japan its greater accuracy might make it better?).

British introduced it in 1940 and were getting rid of it in1941 except for "home guard" use which ought to tell us something about what they thought of it.

A classic case of "shatter" was the US 76mm gun in France. It was called the "Shatter gap". At close range it was discovered the gun could penetrate the front of Panthers and as the range lengthened it could not. Pretty standard right?
Except that as the range lengthened a bit more it started penetrating again and then failed as the range got even longer. The explanation (judge for yourself) was that at close range (0-200yds?) the gun over matched the Panther armor enough that the projectile went through anyway. at the 200-6/800yds(?) ranges the point shattered in spite of the cap and failed to penetrate. At over 6/800yds(?) the velocity had fallen to where the point did not shatter and everything worked as designed and the projectile penetrated. extend the range a bit more (another few hundred yards)and velocity (and energy) had fallen to point where the projectile no longer penetrated.

Wrought Iron is still pretty brittle though? -

It depends, saying wrought iron is a bit like saying steel, it varied in actual composition and in how it was worked so it's tensile strength and other properties varied quite a bit. It is possible to bend wrought iron railings quite a bit before they break.

Sorry, I meant LFH 18 (105mm). HEAT shells are never meant to strike @ high velocities - a gunner who knows what hes doing will not often use them above 500m.

Perhaps for the same reason as the British 25pdr gunners held fire until 400yds or so. With their slow rates of fire and low chances of long range hits they had to take the enemy by surprise and inflict losses with the first shots. engaging in a long range "ranging dual" with the faster firing tanks was a loosing game. The tanks higher velocity guns meant range estimation was less critical, the higher rate of fire meant more feed back on errors quicker and near misses by HE shells on AT guns had a much greater effect on the un-armored AT gun crew than a near miss would have on the tanks

I think the KwK 37 had a max range of 1,200m - maybe more with a very good gunner (even upto 2km maybe). Still, this is mostly using 'bracketing' techniques though - lots of ammo expenditure. I would expect the LFH 18 to do better though?

There were a few occasions of long range duals in dessert with each side using HE (Grants vs MK IVs) with each side hoping to reduce the opposition's numbers before closing range and deciding the engagement with AP ammo. The Germans had used this tactic against the British before the Grant showed up to advantage but it rarely affected the battle (except to lower morale of the British, hard to take fire and not be able to shoot back) . The LHF 18 might be able to do 15-20% better than the KwK 37 but neither are that great even compared to a Sherman gun.

Thanks for the Indian HEAT info. Grants used 75mm AP shells against bunkers - so I think this would be their intended use (though AT work would be interesting, but pointless - unless vs German vehicles, which you said didnt happen - pity!). I would expect a Boyes to keep shooting (but its recil was terrible). It was a really poor weapon, but still useful here (an AT backwater). Jap tanks were cramped though - riveted, which would help. They were so cramped that they required padding! (but were thus a small target - no problem for the accurate Boyes?).

The 20lb HE shell might have performed better against bunkers than the lighter Grant shell. One source gives an HE filling weight of 2 lbs which is about double that of an american 75mm shell.
Yes the Boyes would keep shooting, point being that the Boyes can't relied upon to stop the Japanese tanks although it can get some of them.

A very good point. 400-600yds is scary! I read though, that if the Pont Du Fahs 6pdr gunners had've opened fire at ranges below what they did (aprox 500m) they would not have suceeded. I found an awesome article on this ( shatter-gap), that I posted here in about 2006, but I cant find it for love nor money! (deleted?).

As far as the 6pdrs go because of their much higher velocity they could engage from longer ranges than the field artillery guns.

and as far as shatter goes See:

6 Pounder Anti-Tank Gun

Please note the differences between capped and uncapped projectiles against the two different types of armor. In some of the North African battles the early 6pdrs with UNCAPPED shot may very well have had trouble with face hardened armor. With capped shot supplied face hardened armor seems to have been tamed.

True. The PaK 36s rounds were APCBC though - but I suppose you design to defeat your own armour really (strange, but true!). The lack of /HE in the 2pdr allowed much better penetration than the German 37mm (pity about the shatter/quality). Later spaced armour on the PzIII IV disabled Caps btw... - could tumble AP rounds too.

Going by Ian Hoggs book the Pak 36 rounds were not capped but he could be wrong. Allthough pictures seem to show an uncapped projectile.

http://www.quarry.nildram.co.uk/tank1.jpg

The lack of HE had little to do with the 2pdrs penetration. The much heavier projectile (1077 grams vs the German 37's 680grams) and a higher velocity means that the later 2pdr ammo had 392,000 joules of muzzle energy compared to 200,000 joules for the Pak 36.

- but it wouldnt start a fire?... Youd need the incandescent penetrator for that. If the armour 'tore' - then youd get no 'plug'?.

Again with the fire? if you kill the crew you don't need fire. and you don't need an incandescent penetrator. the metal from the plug is going to be several hundred degrees or more. you don't shove a sizable plug of metal out of an metal plate without creating some heat. If the chunks of metal are big enough and they fall into stored ammo they have been known to start fires.

Thanks for the info. So you're in agreement then? Wonder if we've any AA Arty fans on here? Rommel was often hated by the Luftwaffe for stealing their guns for 'improper use'. It seems he was 100% right though? What about the 3.7in 'Morale' guns in Britain? Still, AAA was apparently very useful against V1s.

Uh, no, not in agreement. I am pointing out you can't use AA guns in a forward position. If you want them as AA guns they have to be deployed where enemy artillery can't reach them. Some people think that Rommel, if not 100% wrong, went a little too far in stripping his AA assets. While it does take thousands of AA shells fired to bring down one bomber (cost trade?and this was known either before the war or very soon after the start) it can be said your AA defense has worked if your enemy has failed to get his bombs on target even if he has had no planes shot down. Would Rommel have gotten more supplies through if his 88s had been doing their AA job? A question we probably can't find the answer to.

Properly sited AA guns, connected to fire control predictors with range and hight finding instruments (optical or radar) and up to date meteorological conditions are not "Morale" guns. it may take them several thousand rounds to bring down a bomber but they are a valuable (all weather, round the clock) part of the defense. Sited by themselves with no predictor (gun director, in navy terms) or fuse setting information they become "morale" guns. Aiming and fuse settings depending on the gun captains judgement and a wetted finger held up to the wind they make a satisfying "bang" on the ground and a black puff in the air but success goes into truly astronomical chances

 

[Shortround6]

Part 3

Thanks, but the German 88mm had a higher RoF than a 7.62mm NATO rifle bullet! (apparently in certain circumstances).

Yes," circumstances" Did the 7.62mm NATO rifle have a semi-automatic breech block and a loader?

The later D-25T improved the RoF much further. Do you think those Wikipedia figures are wrong? How many loaders for the towed versions?

Crew is given as 9 for the towed version, not all are loaders and the ammo has to a moved a greater distance. Changes in breech mechanism may speed things up. Field artillery usually has a manual breech. Somebody in the crew has to manually flip a lever to open the breech block and extract the casing. After the shell and powder charge/casing are rammed into place the same crewman has to close the Breech. Tank guns use semi-automatic breech blocks (usually) where cams operate the breech block during recoil and **** a spring, when the loader rams in the cartridge case the rim trips a catch and releases the spring powered breech block to slam shut.

I heard that from a guy whos relative fought in the war. For e.g. DYK that the T-55s had night vision - but the Centurions didnt? The T-55 was later upgraded by the Israelis, but the base models were better too. They were too small for Israeli crews though.

Since both tanks had careers that spanned over 30 years and had many variations you kind of have to match them up version to version. The T-55 was too small for some Russian crews too. Somebody once said of the of the T-54/55 series "when the Russians run out of strong, left handed midgets they are going to be in trouble"

You actually have a fire engine? Swank!

I don't "have" one I Drive one. It's my job. Some of the first Fire trucks I drove were crash boxes and old ones at that. This is a picture of the current truck;

Truck 1

The rolling resistance of tracks is much higher than your tyres - on one hand it hurts top speed (which is why your truck ha higher top speed), yet when it comes to hills, that rollin resistance is lessened, equated into sheer inertia-beating traction, something your truck could never come near - if it had more power, it would just spin its wheels. Of course, momentum is desireable in a tank too (but less vital).

We don't go off-road. if you think you can spin the tires, eight powered 11.00x 20.00s on the rear bogie going up hill on pavement you are going to need a lot more power. an awful lot more power.

You don't need to tell about momentum, between that and the turbo lag little old ladies with walkers beat us across intersections from a standing start.

Too many gears can cause headaches too, apparently, 3rd gear is the most often used in a tank, but I would say 4 gears is enough? I wonder how many the M18 Hellcat had?...

I would say it depends on power to weight and expected terrain. flat areas need fewer gears than hills.
The Hellcat had 3 gears forward but the torque converter expands the spread quite bit. Torque converters multiply the torque when the input shaft is turning faster than the output shaft until road speed picks up enough that the shaft speeds equalize. Depending on the torque converter you can around double the torque at when the converter is near stall (output shaft near stationary). The WW II torque converters always slipped some but later ones (fire truck included) have "locking" torque converters for better fuel efficiency. sort of makes the 4 speed automatic act like an 8 speed as you watch the tachometer needle.

Do you mean rolling resistance vs grip ground pressure?

No, I mean that slack tracks (loose tracks) have less rolling resistance but are more prone to shedding on turns or in bad terrain.

 

[schwarzpanzer]

Hi tomo,

Sorry, I forgot to reply to your last post, so it's out of order. (hartmann Shotround, you're next. ).

Thats a good point on the ZiS-2s barrel wear. It would have been more expensive because it was a new calibre, probably? - but the construction of the gun itself was very 'Sten-like', so was used to reduce the price of the 76.2mm - the carriage, that is, dunno about the gun. Someone else on here has posted that APCBC was very expensive for the D-10, so maybe it was for the ZiS-2 too? - explaining the higher price (especially per shot). That also explains why the D-10 didn't use APCBC so much - the 57mm was a new calibre, so new ammo could be developed - which was not the case for the old 100mm?

I think the ZiS-2 got a 'second wind' though, and was considered better than the 45mm L66? (Thanks for the info).

It was used in T-34/57 SU-57 tank destroyers, after all - a serious weapon!8)

I suppose its main problem was in being a solution to a problem that didnt exist - then did. Still, better to have something, not need it than...?

100mm info has been posted by Shortround, I'm sure its something we'll get to the bottom of!

I don't have problems reading Serbian forums sites, while my country ( me) was in was with them 15 years ago.

Thats a very good attitude to have IMO, and I respect you for it.

You can take a look at this drawing, with turret almost half of height of KV-2's turret:
KV-1 (107mm gun)

Thanks, very good. I'll have to study KV prototypes more. Battlefield.ru has a good page on it. I dont know whetherthe Beast of Leningrad was a prototype, or a hurriedly re-gunned KV-2 (both turrets look similar). Unfortunately, theres no real good ifo on the net.

My take would be, production versions:
-one version of IS-1 (85mm)

Thats probably about right - there was a 100mm gun version - but it may not have seen service. (The /85 apparently did though).

-two versions of IS-2 (the second version featured glacis plate of constant slope, not cranked)

This is where it might get confusing! The 1st ones were re-gunned IS-1s ( prototypes). There may have been those with the cranked/stepped glacis that were originally built as IS-2s, but I dont know. The 1944 model (sloped glacis) was a production IS-2 at least! There was a proper IS-2M - post-war refitted IS-2s. I think there were 2 version of these?: 1 with the stepped glacis, 1 with the cranked. The info should be on Wikipedia IIRC?

It was good, but not ideal IMO

So long as ATGs were not encountered, it was fine! The obsession with putting such a big gun on turned it into a bad design IMO.

That's vague point...

Lots of drivers commented on it, theres a DVD with a mechanic of one in a Museum saying how bad it was. I don't know if the DVDs available in Croatia? Is there a Croatian Amazon? Anyway, it's called 'Killer Tanks KV'. - a very good DVD! (Also includes pre- post- KV - such as the SMK (IIRC) the IS-2 IS-3). Its cheap too (in the UK).


Thats good info on the KwK 36, thankyou. I think though that HE shells were a lot lighter than AP shells – making for a bigger recoil than HE. Also, I think maybe that HE rounds may have had a reduced load in the cartridge? – further reducing recoil.

The KwK 36 was biased towards AT performance – the 85mm was more evenly balanced.

perhaps the Russkies have done better job converting AA piece to AFV use?

Yes, I think the 85mm should have been much better – it was massively downgraded from its base AA design – whereas the KwK 36 was apparently upgraded ( the 88 had more power than the 85 in the flak role to star with, IIRC). Whether the 85 was cut down to be put on the T-34 I dont know - but it was mouted on the SU-85 1st, the T-34 could almost handle the 100mm, so I dont think so - perhaps the designers were being over-cautious? If it wore the tank out quickly then thats not a problem - as T-34s didnt last that long. Thinking about it though, it was on the KV/85 1st - so maybe problems occured there?

Hmm, the arrogance tends to backfire...

Yes, that often happens - never underestimate your enemy IMO.

Not superior; perhaps even, and that only until Centurion received 105mm.

The 20pdr was found unable to cope (by the British) - hence the 105mm L7, mobility and protection were also far ahead. Optics were not that inferior - even to the 105mm, apparently.


An MBT?, thanks. - yes, this was starting to appear in WW2. Whether the T-34 can be considered one - or the Panther? Tank designations can get confusing at this time - with several different answers.

Shove the Maybach on 'our' KV-88/Panther and you have 30 mph pronto

I'm afraid it mght not be as easy as that - the small, steel wheels would be unsuitable for 30 mph - and would probably stress the engine even more than in the Panther - with its large dia wheels. Steel wheels proved unsuitable on both the Panther T-34 btw. For a heavy tank though, the design would be fine.

That's theory (even if I find some points debatable).
Practice says all-aft layout was better - and it dominated the tank world for some 60-70 years.

I think it only really became practical after the introduction of automatics (even then causing problems in the M6 M26). The Centurions crash gearbox was a pain, as was the T-54s IIRC? The T-34s was hard, but I'm not sure in the Cromwell/Comet - perhaps in lighter vehicles its acceptable? I wonder if you could have an all-aft Preselector setup? - Shortround?

By what accounts it was 'more modern'? The 60 degs are hardly magic, with 30 I'll agree...

Sorry, 60 degrees from vertical, not horizontal. I prefer to use vertical as a starting point when discussing armour.

You can read the Russian accounts when they've tested Pz-III(E?) and T-34 - Pz-III was faster (almost 70 km/h), with 5 crew members vs. 4 of T-34, better ergonomics radio of Pz-III...
Of course, T-34 have had better gun, much better protection off-road performance.

True, the T-34 was better in 'hard' areas of design, but < in 'soft' ones.

I thnk 70kph sounds a bit suss? The T-34 was developed to be more like the PzIII anyway (but far to late IMO).

The road wheels were replaced with ones with bigger radius.

I'll have to check that... I know they were lighter, anyway - reducing all-up unsprung weight (increasing off on-road performance comfort).

Too bad the Brits haven't found the way to convert pre-war 3in AA piece for AFV use in greater numbers; that one would've lay waste in N. Africa.

Actually, they did! - It was mounted in the hull of a Churchill - but onlyused for home defense, rejected. Britain failed to make a good tank destroyer - too obsessed with turrets. The Archer was an attempt though.

OTOH, Commonwealth forces suffered mostly in time Axis forces were equipped with Pz-II Italian tinclads, proving (again) that there is no remedy for bad tactic strategy (save the numeric advantage).

True, but at this time they had very vulnerable A9, A13 A15 Cruisers MKVI Lights.

Think from Normandy on

Thanks, I'll have to keep my eyes peeled for that. Strange I've never heard of it before though. The Fougasse was supposed to be to attack tanks IIRC - so I suppose it makes sense.

 

[tomo pauk]

Hi tomo,

Thats a good point on the ZiS-2s barrel wear. It would have been more expensive because it was a new calibre, probably? - but the construction of the gun itself was very 'Sten-like', so was used to reduce the price of the 76.2mm - the carriage, that is, dunno about the gun.

It was the barrel that was expensive IIRC, a problem further emphasized by notable barrel wear after not-so-many rounds are fired.

Someone else on here has posted that APCBC was very expensive for the D-10, so maybe it was for the ZiS-2 too? - explaining the higher price (especially per shot). That also explains why the D-10 didn't use APCBC so much - the 57mm was a new calibre, so new ammo could be developed - which was not the case for the old 100mm?

For the history of Russian ammo I'm not the good source

I think the ZiS-2 got a 'second wind' though, and was considered better than the 45mm L66? (Thanks for the info).

The difference in performance is akin to the difference between 5cm pak 7,5cm pak (yet, both Soviet ATGs (45L66 57mm) were light enough for manhandling).

It was used in T-34/57 SU-57 tank destroyers, after all - a serious weapon!8)
I suppose its main problem was in being a solution to a problem that didnt exist - then did. Still, better to have something, not need it than...?

Soviets were looking for a multi purpose tank gun, so 76,2mm served them better. Still, too bad they didn't make any more of T-34-57 than token numbers. Not only to tackle Tiger Panther, but to beat older, but improved German AFVs (mainly Pz-IVG/H StuG-IIIF/G).

This is where it might get confusing! The 1st ones were re-gunned IS-1s ( prototypes). There may have been those with the cranked/stepped glacis that were originally built as IS-2s, but I dont know. The 1944 model (sloped glacis) was a production IS-2 at least! There was a proper IS-2M - post-war refitted IS-2s. I think there were 2 version of these?: 1 with the stepped glacis, 1 with the cranked. The info should be on Wikipedia IIRC?

I recommend onwar.com wwiivehicles.com for a quick online reference, but people do tend to look at Wikipedia for that

Lots of drivers commented on it, theres a DVD with a mechanic of one in a Museum saying how bad it was. I don't know if the DVDs available in Croatia? Is there a Croatian Amazon? Anyway, it's called 'Killer Tanks KV'. - a very good DVD! (Also includes pre- post- KV - such as the SMK (IIRC) the IS-2 IS-3). Its cheap too (in the UK).

What's the name of the DVD?
Amazon does ship internationally...

Thats good info on the KwK 36, thankyou. I think though that HE shells were a lot lighter than AP shells – making for a bigger recoil than HE. Also, I think maybe that HE rounds may have had a reduced load in the cartridge? – further reducing recoil.

We can draw parralels between AP ammo too, but the net result wouldve been about the same.
The Soviets did have reduced load for HE shells of their 45mm, albeit with heavier shell - good concept. Think that Italians did the same with Bohler (47mm).

The KwK 36 was biased towards AT performance – the 85mm was more evenly balanced.

Don't think so. Both 'sets' of engineers tried to extract as much of the reliable performance as possible, and I do think both cannons were geared towards good all-around performance (and succeeded in it).

Yes, I think the 85mm should have been much better – it was massively downgraded from its base AA design – whereas the KwK 36 was apparently upgraded ( the 88 had more power than the 85 in the flak role to star with, IIRC).

85mm tank gun have had the same muzzle energy as 85mm AA gun (with same round), so no downgrade there
Sure enough about AA performance, 88L56 have had greater muzzle energy (up cca 20%?)

Whether the 85 was cut down to be put on the T-34 I dont know - but it was mouted on the SU-85 1st, the T-34 could almost handle the 100mm, so I dont think so - perhaps the designers were being over-cautious? If it wore the tank out quickly then thats not a problem - as T-34s didnt last that long. Thinking about it though, it was on the KV/85 1st - so maybe problems occured there?

Don't think there were any problems with 85mm aboard those hulls.

I'm afraid it mght not be as easy as that - the small, steel wheels would be unsuitable for 30 mph - and would probably stress the engine even more than in the Panther - with its large dia wheels. Steel wheels proved unsuitable on both the Panther T-34 btw. For a heavy tank though, the design would be fine.

If those 30mph are achieved on the road, think smallish wheels wouldn't present a problem. Off road, the max speed would have been reduced anyway.

Sorry, 60 degrees from vertical, not horizontal. I prefer to use vertical as a starting point when discussing armour.

That makes sense

Actually, they did! - It was mounted in the hull of a Churchill - but onlyused for home defense, rejected.

I know, that's why I've said 'in greater numbers'

Britain failed to make a good tank destroyer - too obsessed with turrets. The Archer was an attempt though.

They might have tried to mate it (3in) with hull of M3 (Grant).

 

[Shortround6]

"They might have tried to mate it (3in) with hull of M3 (Grant)."

It was done. It wasn't pretty.

Google Image Result for http://mailer.fsu.edu/~akirk/tanks/UnitedStates/selfpropelledguns/usspg-T24-a.jpg

Scroll down to the T24 and the T40

for real giggles see the T1/M5

OK it wasn't a British 3in gun but be careful what you ask for,

You just might get it

 

[tomo pauk]

Not very pretty

I wast thinking along the lines of an 'American StuG', or 'American SU-85' (US-85? ), but this (M3 with 3in) does look rather Marder-ish...

The other ones you post about are pretty ugly, though I like US self-propelled pieces.