Armor Penetration - 20mm vs. .50 cal.

[Soren]

That is obviously untrue. Just last night I was watching a interview with a Tiger tank commander, he said his tank and others broke down frequently, and that they waited for repairs "until the end of the war". He was talking about late in the defense of Normandy.

No it is definitely not untrue ! Only Tiger-II's had reliability problems from 44 and onwards !

The Panthers teething problems had been solved shortly after the Kursk battle (43), while at the same time the Tiger-I's were getting very reliable.

There was one problem though, if one DID brake down, the spear parts were very hard to get a hold of quickly.

All tanks broke down frequently. As I recall, the MTBF of the Sherman in typical operation was about 1300 miles, for the Panther, it was about 400 miles, and for the Tiger I, about 100 miles. Failure being defined as any repair that could not be made by the crew in half an hour - i.e., a track link replacement was not counted.

And that is the Biggest lie ever made about those tanks !

The Panther was VERY reliable after its problems from the Kursk battle had been solved, and the Tiger-I also became very reliable from then on.

The Tiger-II however was not so reliable, its gearbox would frequently break, as it couldnt handle all the weight. The Engine however had no problem pulling the tank, but the Gearbox wich was designed for the 25 ton lighter Panther just couldnt cope with the much extra weight put on it.

I think the crankers were not in a great position to see and properly aim the gun

Well they are.

Seriously, do you think 2-3 men can aim the gun effectively?

I don't think they could, I know they could.

For a main gun on a tank that is probably true

No for a tankgun this actually isnt true, wich the Soviets learned the hard way.

,

but for AA guns I don't believe it one bit. There is just no way a gun can be aimed as effectively by commitee as by one gunner.

Well then you go ahead and believe what you wanna believe, but this is the truth ! If electrically driven AA guns were both faster AND more accurate, then there wouldnt be any Crank driven ones made ! Simple as that.

Again, watch the movie - it is pretty darn clear the German small field AA was damn ineffective. So much so that the Tempests virtually ignore it.

That movie proves nothing, as its only 'one' movie and most probably a "staged" one.

 

[Anonymous]

That is obviously untrue. Just last night I was watching a interview with a Tiger tank commander, he said his tank and others broke down frequently, and that they waited for repairs "until the end of the war". He was talking about late in the defense of Normandy.

No it is definitely not untrue ! Only Tiger-II's had reliability problems from 44 and onwards !

The Panthers teething problems had been solved shortly after the Kursk battle (43), while at the same time the Tiger-I's were getting very reliable.

There was one problem though, if one DID brake down, the spear parts were very hard to get a hold of quickly.

Well, I'm watching "World War II - Greatest Military Clashes - Sherman vs. Tiger" right now, and Hans Bleidessel (not sure i got the spelling right) is giving a totally different story. Watch this show, 21 minutes into the episode, and listen to what he says. It will run again tommarow at 1am EST and 9am EST on The Military Channel. He very specifically says the Tiger I broke down frequently and that both parts and qualified mechanics were virtually unavailable. Very clearly he is talking about Normandy, not Kursk, and the Tiger I, not the Tiger II.

BTW: You should watch the second half hour too - Spitfire vs Bf109 in the BoB - listen to what "Charlie Brown", who flies both planes, has to say. Or Hans Eckkard Bob - a German pilot's comments. Both agree the 109 was much harder to handle than the Spitfire. The first impressions of the two WWII pilots in their opponent aircraft is interesting too.

All tanks broke down frequently. As I recall, the MTBF of the Sherman in typical operation was about 1300 miles, for the Panther, it was about 400 miles, and for the Tiger I, about 100 miles. Failure being defined as any repair that could not be made by the crew in half an hour - i.e., a track link replacement was not counted.

And that is the Biggest lie ever made about those tanks !

The Panther was VERY reliable after its problems from the Kursk battle had been solved, and the Tiger-I also became very reliable from then on.

The Tiger-II however was not so reliable, its gearbox would frequently break, as it couldnt handle all the weight. The Engine however had no problem pulling the tank, but the Gearbox wich was designed for the 25 ton lighter Panther just couldnt cope with the much extra weight put on it.

According to post-war studies performed by the US Bureau of Ordnance US tanks were 5 times more reliable than their German counterparts, and that is averaging all German armor types together. Soviet sources also claim that the T-34 was more reliable than the German Tanks, and that the lend lease M4A2 (deisle powered - least reliable of the Shermans) was more reliable than the T-34.

The gearbox was not reliable on the Panther or especially Tiger. The final drive and drive sprocket shafts were problems for all large tanks on all sides until the late 50's and even into the 60's! The Panther was not so bad, but still not "reliable" when compared to smaller tanks like the Panzer IV or Sherman. The Tiger was unreliable througout its career.

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Well then you go ahead and believe what you wanna believe, but this is the truth ! If electrically driven AA guns were both faster AND more accurate, then there wouldnt be any Crank driven ones made ! Simple as that.

In order to not use a crank you have to have an alternative - the Germans did not. Hydrolic systems were too heavy and too unreliable in the field, and they were too slow anyway. The Tiger for instance (watch the episode above) took well over a minute to rotate the turret even under engine (hydrolic) power, where the Sherman's electric turret could rotate 360 degrees in 15 seconds in normal mode, faster in "burst mode" (I'm not sure it could do a whole rotation in burst mode).

And without the ALNICO magnet the Germans could not build a fast light electric motor. So they had to use muscle power for mobile AA. For fixed AA they could draw power from a generator and attain sufficent power to overcome the weakness of their iron magnets.

Again, watch the movie - it is pretty darn clear the German small field AA was damn ineffective. So much so that the Tempests virtually ignore it.

That movie proves nothing, as its only 'one' movie and most probably a "staged" one.

LOL - sure it's staged... BY THE GERMANS! It is a German propoganda film. You need to watch that movie Soren!

Right click on it and "save target as", then view it in Quicktime (or I think the latest Windows Media Player will show it too). Trying to run it direct off this website may cause it not to load.

=S=

Lunatic

 

[Soren]

Well, I'm watching "World War II - Greatest Military Clashes - Sherman vs. Tiger" right now,

And that right there totally neglates all your merits !

50% of all that is shown on History Channel is pure crap, and has been proved wrong by specialists thousands of times !

I must admit I'm surprised to hear that your relying on History Channel as a primary reference ! (No wonder your so Pro-U.S. )

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

Also how do you think that it could be established that U.S. tanks were 5 times more reliable than German ones ? Thats right it couldnt, and its pure History-channel crap !

The Tigers in Normandy were reliable if proper maintenance was done, but if broke down, parts were hard to get (Wich is why 'one' Vet's experience isnt at all enough to establish anything)

Read: "Tiger 1 Heavy Tank 1942-1945" by Tom Jentz and Hilary Doyle.

The Panthers were VERY reliable, and i havent heard or read a single account of one braking down in Normandy or beyond !

Perhaps you could find a more "Reliable" source than H-Channel that supports your claims ?

I find Tom Jentz's books very detailed.

 

[Anonymous]

Well, I'm watching "World War II - Greatest Military Clashes - Sherman vs. Tiger" right now,

And that right there totally neglates all your merits !

50% of all that is shown on History Channel is pure crap, and has been proved wrong by specialists thousands of times !

I must admit I'm surprised to hear that your relying on History Channel as a primary reference ! (No wonder your so Pro-U.S. )

The only comment I'm referencing is that of a German tank commander who commanded a Tiger I at Normandy. I agree the rest of the analysis is relatively meaningless.

Watch the show and listen to his comments about reliability, it will be comming on again in little over an hour.

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

Also how do you think that it could be established that U.S. tanks were 5 times more reliable than German ones ? Thats right it couldnt, and its pure History-channel crap !

No, if you would read, that figure comes from the US Army Ordinace department. If I recall correctly, that figure was based upon the number of miles the tank could travel before suffering a failure which would prevent it from being able to engage in combat. Simple tread repair and other quick (5-10 minute) repairs were not considered dehabilitating. The average distance traveled between such failures for German tanks of all types was about 300-350 miles, where for the Sherman it was 1200-1400 hundred miles.

The Tigers in Normandy were reliable if proper maintenance was done, but if broke down, parts were hard to get (Wich is why 'one' Vet's experience isnt at all enough to establish anything)

Read: "Tiger 1 Heavy Tank 1942-1945" by Tom Jentz and Hilary Doyle.

Sure, and "proper maintainence" consisted of significant work on the tank every couple of hundred miles.

The Panthers were VERY reliable, and i havent heard or read a single account of one braking down in Normandy or beyond !

Perhaps you could find a more "Reliable" source than H-Channel that supports your claims ?

Again, my source is the US Army Ordinance department's post-war reliability evaluation, I believe concluded in 1947. I'm trying to re-locate the report so I can fully quote it and how the figure was calculated. The focus was on what to expect if war broke out against the Soviets, and it was a classified report until the late 80's.

I find Tom Jentz's books very detailed.

Good for you. Quote it and give the references.

Also, no one book is the "tell all" about such a subject either. From a brief research of Tom Jentz, he is clearly invested in the Panzers and as such is likely to portray them in an overly favorable light.

 

[Soren]

RG you didnt say anything about the Sherman !! You said U.S. tanks, as in General, wich isnt true at all !

Yes I will most definitely agree that the Sherman was more reliable, as it was THE most reliable tank of WW2 !

Russian Farmers have been using an old WW2 Sherman Chassis+Engine up until 1996 for farm work ! No'one is questioning the SHermans reliability here !

 

[Anonymous]

RG you didnt say anything about the Sherman !! You said U.S. tanks, as in General, wich isnt true at all !

Yes I will most definitely agree that the Sherman was more reliable, as it was THE most reliable tank of WW2 !

Russian Farmers have been using an old WW2 Sherman Chassis+Engine up until 1996 for farm work ! No'one is questioning the SHermans reliability here !

All USA tanks were very reliable (relatively speaking), with the possible exception of the Pershing. The Sherman however made up such a majority of the US tanks in service that it would dominate any statistic w.r.t. US Armor.

Which US tank are you implying was unreliable?

=S=

Lunatic

 

[Soren]

All USA tanks were very reliable (relatively speaking), with the possible exception of the Pershing.

Yes reliable, but not more reliable than the Panther or PzIV !

Don't compare the M4 Sherman with the Panther or Tiger, or even the PzIV in reliability as the M4 Sherman will make any tank look bad by comparison !

No WW2 tank tank beats the M4 Sherman in reliability !

The Sherman however made up such a majority of the US tanks in service that it would dominate any statistic w.r.t. US Armor.

Yes, and the statistic is probably only based on Shermans. (Although the statistic aint all good, as the Sherman got knocked out in huge numbers by the Germans !)

Alot of Shermans got knocked out after only 1 or 2 days in service.

Which US tank are you implying was unreliable?

The M26 Pershing for one, this tank was even worse in reliability than any German heavy tank !

 

[Anonymous]

All USA tanks were very reliable (relatively speaking), with the possible exception of the Pershing.

Yes reliable, but not more reliable than the Panther or PzIV !

Don't compare the M4 Sherman with the Panther or Tiger, or even the PzIV in reliability as the M4 Sherman will make any tank look bad by comparison !

No WW2 tank tank beats the M4 Sherman in reliability !

The Sherman however made up such a majority of the US tanks in service that it would dominate any statistic w.r.t. US Armor.

Yes, and the statistic is probably only based on Shermans. (Although the statistic aint all good, as the Sherman got knocked out in huge numbers by the Germans !)

Alot of Shermans got knocked out after only 1 or 2 days in service.

Which US tank are you implying was unreliable?

The M26 Pershing for one, this tank was even worse in reliability than any German heavy tank !

I specifically excluded the M26 Pershing, so why do you bring it up. Given that only a handful saw action, it is not significant. And it was no less reliable than the Tiger. Just like the Tiger, it had final drive problems, but other than this weakness, it was more reliable than the Tiger.

What other US tank was less reliable than the Panther or Tiger? NONE!

The Panther Ausf. G was not terrible, but the Ausf. A and D were. And something around half the Panthers in service were Ausf. A's and D's. By the time the Panther G's entered service, the German's were really already beaten anyway.

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Getting back to my original point, the Panzer IV was quite reliable. What the German's should have done was produced this tank in far greater numbers. Either it should have been upgraded with the 75mm L70 gun (possibly requring an updated turret) or the tank destroyer versions with that gun should have been produced in far greater numbers specifically to kill tanks. The Panther should have been brought into production more methodically, avoiding the production of almost 3000 highly unreliable units.

During the whole war, only about 9000 Panzer IV's, 5000 Panzer V's, and 1350 Panzer VI (Tiger I's) were produced. Had the German's sought to produce the Panzer IV in quantity rather than trying to change over to the Panther quickly and underake the Tiger at all, they might have produced 30,000 Panzer IV's and still managed another 3500-5000 Panthers before wars end. The Panzer IV was a very servicable tank in every respect, and it could probably have been significantly improved upon without having to add another 20+ tons of weight to it.

=S=

Lunatic

 

[Soren]

I specifically excluded the M26 Pershing, so why do you bring it up.

Oh, so the M26 Pershing aint a U.S. design or what ?

And it was no less reliable than the Tiger. Just like the Tiger, it had final drive problems, but other than this weakness, it was more reliable than the Tiger.

Total BS, even the Tiger-II was more reliable than the Pershing !

Read Hunnicut's book about the M26 Pershing, and you will ralize this.

What other US tank was less reliable than the Panther or Tiger? NONE!

Well what other U.S. Medium-Heavy tanks were there that didnt run on the same Sherman chassis ? Not many !

The Panther Ausf. G was not terrible, but the Ausf. A and D were.

No only the D model had severe reliability problems, this was corrected with the A model.

Read: "Panther Medium Tank 1942-45" by Stephen A. Hart.

 

[CharlesBronson]

Interesting pictures of tugsten core cal .50 versus 38,1 mm ( 1 1/2 inch) steel plate.

 

[Matt308]

Here is an interesting analysis...

http://www.geocities.com/CapeCanaveral/Hangar/8217/fgun/fgun-in.html

Matt

 

[delcyros]

Sorry for jumping that late into this debate.
It is all very interesting. I hope to contribute a bit.
At first armor penetration by massive objects (AP rounds, not HEAT- based damage) is mathematically reasonably known.
The main question was wether 0.50 cl. or 20mm Hispano´s are a better armor penetrator. The problem with armour penetration results is that
THERE ARE NO ARMOR QUALITY ANALYSIS GIVEN FOR THE TEST
SAMPLES.
This makes it very hard to verify the datas. It should also be considered how often the armour was weakened, where exactly the test sample was hit and under which circumstances (striking velocity and impact obliquity).
I would like to include MG 151/15, MK 101/30mm and MK 103/30 into comparison as well as soviet guns alike VYa 23mm (all these have been used against tanks in ww2).
Here are my computations on the base of M79APCLC (which´s basing projectile nose is in the middle between very pointed and blund shaped nose bodys) from Nathan Okun. I don´t know how to extrapolate the deceleration of the rounds and the correct angle of fall, so I start with theoretical max. penetration figures on pointblanc range (muzzle velocity=striking velocity). All against armor of 260 Brinell hardness in average (no more than 8% difference in acceptance limits by tapering down allowed) and 25% elongation (this is a very tough armor quality for ww2 tanks, considerably better than Panther, T-34, Matilda and even Tiger I and Sherman) KEEP IN MIND THAT "PENETRATION" IS HYPOTHETICAL, since I couldn´t perform computations due to a lack in deceleration and ballistic angle of fall for range figures. Any help with this is greatly appreciated, gentlemen! TAKE THESE FIGURES AS MAX. POSSIBLE AND UNEXCEEDABLE ONES.
gun---------poj.weight--------muzzle velocity------obliquity------penetration
UBK-----52 g (0.115lbs)-------860 m/s.--------------0--------------45 mm-
0.50M2--43.3 g.(0.095lbs)-----880 m/s.--------------0--------------40 mm-
15/151---52 g.(0.115lbs)------1040m/s.*------------0--------------62 mm-
20/151---117g (0.258lbs)-----720 m/s.---------------0--------------34 mm
20mm MKII-130g(0.29lbs)----880 m/s.---------------0--------------53 mm-
23mm YVa-200g(0.441lbs)----880 m/s.--------------0--------------60 mm-
Ho115-----253g(0.557lbs)-----710 m/s.--------------0--------------36 mm-
MK101----330g (0.767lbs)-----920 m/s---------------0--------------71 mm-
MK103----330g (0.767lbs)-----860 m/s.--------------0--------------64 mm-
US37M9--744g (1.638lbs)------860 m/s--------------0---------------87 mm-
NS37-----748g(1.647lbs)------890 m/s.--------------0---------------92 mm-


* other sources rate them to 905 m/s (HE-round as I now know). I took the APR-round figure (max. possible, thanks for the info!) And I recalculated. The theoretical penetration INCREASES because of a smaller tungsten core diameter despite of a somehow lower weight!!!, Here the max. possible penetration for original AP-ammo with 850m/s 72g Ap round MG 151/15: 46 mm!)
(to be continued for higher obluquities)

 

[Jabberwocky]

Del:

The Mg151/15 did indeed fire a round at 1,040 m/sec. It was a special, tungsten tipped AP round called the AP40. However, in order to boost the velocity so high, it was much lighter than the standard MG151/15 round, weighing just 52 grams, compared to the standard AP rounds 72 grams and 57 grams for the HE round.

So AP performance of the AP40 might be less than your theoretical maximum.

 

[elmilitaro]

Nice info. 8)

 

[delcyros]

Here are the other figures:
Now on 30 degrees obliquity:------------and 60 degrees impact obliquity*:
gun----------------penetration(@30 degrees)------penetration (@60degr.)
UBK------------------40 mm--------------------------11.2 mm
US 0.50M2-----------36 mm--------------------------9 mm
15/151 AP 72g------45 mm--------------------------12 mm
15/151 APR 52g-----55 mm--------------------------14.7 mm
Hispano 20mm MKII 48 mm-------------------------12.9 mm
23mm YVa-----------54.6 mm-----------------------14.7 mm
Ho115----------------33.3 mm-----------------------11.2 mm
MK 101---------------64.8 mm-----------------------18.5 mm
MK 103---------------62.2 mm-----------------------17.5 mm
US 37mm M3--------79.5 mm-----------------------21.7 mm
NS 37----------------82 mm--------------------------22.6 mm


* The used figure of elongation, 25% makes the armor the most ductile and therefore extremely hard to penetrate at 60 degrees. It should be noted that most tank armor had less elongation (usually between 14 and 23%). Only naval ww2 armor, such as US class B in thin thicknesses or brand new US STS armor grade construction steels figured 25% elongation.

A last note. While all figures are pretty close at zero range, we still have to keep in mind that the projectiles have a different deceleration in flight. This means the figures will open up with the range, usually the haevier shells (or those with better ballistic coefficient) benefit more from this with longer range.

 

[red admiral]

http://www.quarry.nildram.co.uk/CannonMGs.htm

Have a read of this article.

 

[Twitch]

I enjoy and appreciate the data presented here on the aircraft weapons. But we must remember that it takes a pilot to put the ordnance on target no matter how potent or puny it may be. I have found most pilots did the best with what they had and scored kills nevertheless. The aces were genuine shooters and could connect ordnance with targets efficiently regardless of ballistics data. That's the key- compensating. Lead and deflection are acquired skills and can't be made up for with the weapon or ammo.

 

[delcyros]

You are correct, Twitch. But the original question was wether a aircraft gun will defeat armor of tanks or not. Pilot skills are necessary but You simply can´t overcome the shortness of your weapon in this regard. Armor penetration happens or happens not, and it doesn´t belong to pilot skill.

I prepare three examples: One for a Typhoon attacking a Tiger I, one for a P-47 attacking a Pz-IV and one for a Hs-129 B1 attacking a T-34. Both with guns only. Just to see if it is possible or not.

 

[delcyros]

1.) Hawker Typhoon Ib with four 20 mm Hispano Suiza MK II. The MK II has a slightly improved AP-capabilty thanks to a higher muzzle velocity. It fires a 130 gr. weight AP projectile with crh4 nose (ogaviel) at 880 m/sec. muzzle velocity. According to Lunatics database it´s striking velocitys in flight are as following:
0 m: 879 m/s; 100 m: 807 m/s.; 200 m: 738 m/s.; 300 m: 673 m/s.; 400m: 612 m/s. The initial penetration is up to 53 mm armor grade material at 0 degrees impact angle.
It´s target is the vaunted Tiger I tank (compare armor scheme of early models in clean configuration below). It´s armor is very ductile and comparably soft. 255-265 Brinell hardness with close to 21% elongation makes it one of the finest ww2 tank armors. The Tiger depends on verticle armor , this may be a disadvantage in close combat tank vs. tank, but as we will see, it makes it very problematic to attack from the air. The only theoretically penetratable armor area are the horizontal turret and hull roofs. Both have 28 mm (1.1") armor.
Since full 90 degrees dives are excluded for Typhoons and even 60 degrees doesn´t seem plausible to me (this is a fighter bomber, not a dive bomber) I expect an approach angle between 15 and 45 degrees from the vertical. This will imply an impact obliquity of between 45 and 75 degrees at perfect longitudinal direction. Let´s assume the pilot is a real scary one and will dive in for 45 degrees. He correctly aims for the tanks roof and opens fire at 600 m distance, leaving enough altitude (around 1000ft.) to recover from the dive. Are 20mm MKII able to hurt the Tiger?
Impossible. The aircraft round will have a striking velocity of 1.660 ft./sec. (+, since it will benefit from 45 degrees fall), but it would need 800 ft. /sec. more to penetrate 1.1" of Tiger-I armor. How close has the Typhoon to dive at the Tiger-I for succefull penetration of it´s guns at 45 degrees?
Can tell You. With 730 m/sec. minimum striking velocity the limit is reached at between 210 and 230 m distance. There would be only 300 ft. altitude left to recover from a 45 degrees five. This sounds like a dirty nap for me.

 

[Magister]

I think Lunatic's muzzle velocity is too high but I don't have any data to support my assertion.

Do not forget to add the velocity of the aircraft to the initial muzzle velocity of the projectile. At 375mph, that's 550 feet per second!