What prevented the QF 3.7-inch AA gun being used in the Anti Tank role.

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Gooner1
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Re: What prevented the QF 3.7-inch AA gun being used in the Anti Tank role.

Post by Gooner1 » 30 Nov 2018 18:05

Don Juan wrote:
30 Nov 2018 17:08
This is what the published German figures and scientific testing by the Ordnance Board confirm.
Different nations calculated their penetration estimates with differing criteria, against different qualities of armour plate at different ranges and angles. And then filled everything else in using a slide-rule.

For the Nth time, the 5cm gun had capped projectiles of roughly twice the weight of the uncapped 2-pdr shot. They were also High Explosive shells for the gun.

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Re: What prevented the QF 3.7-inch AA gun being used in the Anti Tank role.

Post by Don Juan » 30 Nov 2018 18:12

Gooner1 wrote:
30 Nov 2018 18:05
Different nations calculated their penetration estimates with differing criteria, against different qualities of armour plate at different ranges and angles. And then filled everything else in using a slide-rule.
And yet the British and Germans came up with remarkably similar figures.
Gooner1 wrote:
30 Nov 2018 18:05
For the Nth time, the 5cm gun had capped projectiles of roughly twice the weight of the uncapped 2-pdr shot. They were also High Explosive shells for the gun.
For the Nth time, a projectile from the 5cm KwK 38 left the barrel about 400 fps slower than a projectile from the 2 pounder.

Although I will admit that a 5cm APC round hitting the side of a Matilda from 1000 yards will make a much louder clang than 2 pounder AP.
"The demonstration, as a demonstration, was a failure. The sunshield would not fit the tank. Altogether it was rather typically Middle Easty."
- 7th Armoured Brigade War Diary, 30th August 1941

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Re: What prevented the QF 3.7-inch AA gun being used in the Anti Tank role.

Post by MarkN » 30 Nov 2018 18:34

Gooner1 wrote:
30 Nov 2018 17:59
Anyway In this instant its clear they were patient in their attack. Their superiority in armament allowed them to be.
Anyway, in numerous instances, its clear the Germans were patient in their attack, and did so when threats - such as the 2-pdr - had been neutralized. The British, on the otherhand, started their charge at a set time irrespective of the state of the enemy. The difference between the two has NOTHING to do with the equipment each held.

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Re: What prevented the QF 3.7-inch AA gun being used in the Anti Tank role.

Post by MarkN » 30 Nov 2018 18:39

Gooner1 wrote:
30 Nov 2018 18:05
Don Juan wrote:
30 Nov 2018 17:08
This is what the published German figures and scientific testing by the Ordnance Board confirm.

Different nations calculated their penetration estimates with differing criteria, against different qualities of armour plate at different ranges and angles. And then filled everything else in using a slide-rule.

For the Nth time, the 5cm gun had capped projectiles of roughly twice the weight of the uncapped 2-pdr shot. They were also High Explosive shells for the gun.
For the Nth time, the German and British testing produced rather similar results.

For the Nth time, the documentary and practical evidence suggests the 5cm gun capped projectiles of roughly twice the weight (KwK38 L/42) had similar hitting power to the uncapped 2-pdr shot.

For the Nth time, the lack of 2-pdr HE shell is a user problem not a failure of the gun.

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Re: What prevented the QF 3.7-inch AA gun being used in the Anti Tank role.

Post by Don Juan » 30 Nov 2018 18:54

MarkN wrote:
30 Nov 2018 18:39
For the Nth time, the documentary and practical evidence suggests the 5cm gun capped projectiles of roughly twice the weight (KwK38 L/42) had similar hitting power to the uncapped 2-pdr shot.
The weight thing is a bit of a red herring anyway. Any fule kno that the 3.23 kg 6 pounder APCBC round had much better penetration than the twice as heavy 6.63 kg US M61 75mm APCBC round. This was down to initial muzzle velocity.

Also worth remembering that when HV 2 pounder ammunition was introduced it actually out-performed the 5cm KwK 38 (though not the KwK 39).
"The demonstration, as a demonstration, was a failure. The sunshield would not fit the tank. Altogether it was rather typically Middle Easty."
- 7th Armoured Brigade War Diary, 30th August 1941

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Re: What prevented the QF 3.7-inch AA gun being used in the Anti Tank role.

Post by MarkN » 30 Nov 2018 19:19

Don Juan wrote:
30 Nov 2018 18:54
MarkN wrote:
30 Nov 2018 18:39
For the Nth time, the documentary and practical evidence suggests the 5cm gun capped projectiles of roughly twice the weight (KwK38 L/42) had similar hitting power to the uncapped 2-pdr shot.
The weight thing is a bit of a red herring anyway. Any fule kno that the 3.23 kg 6 pounder APCBC round had much better penetration than the twice as heavy 6.63 kg US M61 75mm APCBC round. This was down to initial muzzle velocity.

Also worth remembering that when HV 2 pounder ammunition was introduced it actually out-performed the 5cm KwK 38 (though not the KwK 39).
It's not a red herring, it's a straw being tightly grasped by Gooner1. :lol:

It's similar to other straws he's grasping at. Apparently, pantser crews only fired at - and hit - the most heavily armoured part of the opposing pantsers. The idea that a pantser crew might try to aim for and hit a weaker part of an opposing pantser is ignored - because that would deny the "bloody useless" claim and so on.

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Re: What prevented the QF 3.7-inch AA gun being used in the Anti Tank role.

Post by MarkN » 02 Dec 2018 21:40

Don Juan wrote:
30 Nov 2018 15:38
The 60mm armour of the Valentine and the 75mm armour of the Matilda were more than equal to the frontal armour of the Panzer III, and on those British tanks the thick armour covered a far larger portion of the vehicle.
PanzerArmeeAfrika had 16 of its 24 88mm guns sited in stutzpunkte between Sidi Omar and Halfaya. 15. And 21.Pz-Div had just 4 each. Orders had already been issued for a redeployment of 88s for the planned assault on Tobruk however, they were never implemented as Op CRUSADER kicked off. Only 4 of the 16 on the Sollum front were taken away ... and they were used to deal with the breakout from Tobruk.

Maybe it was planned or maybe it just fell that way, but the Germans ended up with 12 88mm to deal with 1ArmyTankBde's 150ish infantry tanks whilst just 8 were available to deal with the 450ish cruiser tanks of 7ArmdDiv.
Don Juan wrote:
30 Nov 2018 15:38
Its almost as though the British were using the wrong type of tank for their tank vs. tank engagements.
The 'lesson learned' from Op BREVITY was not to use infantry tanks in armoured divisions. Discuss. ;)

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Re: What prevented the QF 3.7-inch AA gun being used in the Anti Tank role.

Post by MarkN » 02 Dec 2018 21:45

MarkN wrote:
30 Nov 2018 17:22
Going back to the 'flaming tank' topic.

The second point to note, flowing from the reality that German pantsers also went up in flames, is the existence of yet another myth: the flaming tank was down to the Germans having AP rounds with bursting charges and the British reduced to solid shot AP only (and a few ex APHE rounds with sand inserted in the place of HE!!!).
Quoting myself and going back again...

I've found a 'lessons learned' document issued by GHQ ME stating this very point: Crusader tanks going up in flames due to German exploding rounds. Is this the start of the myth? Document is from beginning of December 1941?

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Re: What prevented the QF 3.7-inch AA gun being used in the Anti Tank role.

Post by Gooner1 » 03 Dec 2018 13:13

MarkN wrote:
30 Nov 2018 18:39
For the Nth time, the documentary and practical evidence suggests the 5cm gun capped projectiles of roughly twice the weight (KwK38 L/42) had similar hitting power to the uncapped 2-pdr shot.
Fantasy.
Kinetic energy at muzzle:
2-pdr: 338,723 Joules
5cm L/42: 483,302 Joules

For the Nth time, the lack of 2-pdr HE shell is a user problem not a failure of the gun.
What because the users lacked the ability to magick 2-pdr Shot into High Explosive?
The inadequacy of the 2-pdr is in no small part due to ammunition provided.

Soviet tests of the 2-pdr against a Pz38:
"The 40 mm AP shell does not penetrate front armour 50 (25+25) mm thick. The reason for this is poor quality of the shells. They are destroyed completely on impact.
The 30 mm side armour can be penetrated from 800-1000 meters."
Stug III
"At 50 meters, the 2-pounder only forms a 20 mm deep dent in the StuG's front armour. However, at 100 meters, it manages to penetrate the upper part of the front plate. That result does not repeat, as another shot from 100 meters only makes a 25 mm deep dent. 4 shots from the side, all at 850 meters, go through.
Conclusion: "The 40 mm tank gun penetrates the side of the hull, 30 mm thick, from 850 meters. The front of the hull, 50 mm thick, is not reliably penetrable at any distance due to the poor shell quality. Upon impact, the shells shatter into small fragments."
Pz III
The results are similar to the StuG. It cannot penetrate the front at 100, or even 50, meters.
In the conclusions, the following is noted: "The British 40 mm shell, when fired at a 50 mm armour plate from 50-100 meters, makes a 20-25 mm dent and shatters. "
http://tankarchives.blogspot.com/2013/0 ... tanks.html

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Re: What prevented the QF 3.7-inch AA gun being used in the Anti Tank role.

Post by Gooner1 » 03 Dec 2018 13:25

MarkN wrote:
02 Dec 2018 21:40
PanzerArmeeAfrika had 16 of its 24 88mm guns sited in stutzpunkte between Sidi Omar and Halfaya. 15. And 21.Pz-Div had just 4 each. Orders had already been issued for a redeployment of 88s for the planned assault on Tobruk however, they were never implemented as Op CRUSADER kicked off. Only 4 of the 16 on the Sollum front were taken away ... and they were used to deal with the breakout from Tobruk.

Maybe it was planned or maybe it just fell that way, but the Germans ended up with 12 88mm to deal with 1ArmyTankBde's 150ish infantry tanks whilst just 8 were available to deal with the 450ish cruiser tanks of 7ArmdDiv.
1st Army Tank Brigade only began Crusader with 132 tanks and had heavy losses - 46 tanks - taking the fortified Omars. Amongst the defenders were a
single battery of 88s.

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Re: What prevented the QF 3.7-inch AA gun being used in the Anti Tank role.

Post by Gooner1 » 03 Dec 2018 14:29

MarkN wrote:
30 Nov 2018 18:34
Anyway, in numerous instances, its clear the Germans were patient in their attack, and did so when threats - such as the 2-pdr - had been neutralized. The British, on the otherhand, started their charge at a set time irrespective of the state of the enemy. The difference between the two has NOTHING to do with the equipment each held.
Oh, FFS, the difference between the two is that the German guns had superior effective range.

That leaves the British side the option of advancing or retreating if tanks, and firing or just taking it if anti-tank guns.

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Re: What prevented the QF 3.7-inch AA gun being used in the Anti Tank role.

Post by Urmel » 03 Dec 2018 17:11

Gooner1 wrote:
03 Dec 2018 13:25
MarkN wrote:
02 Dec 2018 21:40
PanzerArmeeAfrika had 16 of its 24 88mm guns sited in stutzpunkte between Sidi Omar and Halfaya. 15. And 21.Pz-Div had just 4 each. Orders had already been issued for a redeployment of 88s for the planned assault on Tobruk however, they were never implemented as Op CRUSADER kicked off. Only 4 of the 16 on the Sollum front were taken away ... and they were used to deal with the breakout from Tobruk.

Maybe it was planned or maybe it just fell that way, but the Germans ended up with 12 88mm to deal with 1ArmyTankBde's 150ish infantry tanks whilst just 8 were available to deal with the 450ish cruiser tanks of 7ArmdDiv.
1st Army Tank Brigade only began Crusader with 132 tanks and had heavy losses - 46 tanks - taking the fortified Omars. Amongst the defenders were a
single battery of 88s.
And a substantial mine field.
The enemy had superiority in numbers, his tanks were more heavily armoured, they had larger calibre guns with nearly twice the effective range of ours, and their telescopes were superior. 5 RTR 19/11/41

The CRUSADER Project - The Winter Battle 1941/42

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Re: What prevented the QF 3.7-inch AA gun being used in the Anti Tank role.

Post by MarkN » 03 Dec 2018 17:59

Gooner1 wrote:
03 Dec 2018 13:13
MarkN wrote:
30 Nov 2018 18:39
For the Nth time, the documentary and practical evidence suggests the 5cm gun capped projectiles of roughly twice the weight (KwK38 L/42) had similar hitting power to the uncapped 2-pdr shot.
Fantasy.
Really? Is that how you describe docimented results from practical tests? :roll:
Gooner1 wrote:
03 Dec 2018 13:13
Kinetic energy at muzzle:
2-pdr: 338,723 Joules
5cm L/42: 483,302 Joules
And? You seem to have forgotten that the 40mm round presents a somewhat smaller surface area to the 50mm round on impact. Now calculate that into the penetrating power calculation.
Gooner1 wrote:
03 Dec 2018 13:13
For the Nth time, the lack of 2-pdr HE shell is a user problem not a failure of the gun.
What because the users lacked the ability to magick 2-pdr Shot into High Explosive?
The users didn't lack the ability to make a pure HE shell for the 2-pdr, they chose not to because it didn't suit their practical doctrine of how to do tank and anti-tank warfare. They had an APHE round from the very beginning of the war but decided it was less effective than the AP round so discontinued its manufacture and, in Egypt, even removed the HE content from their remaining APHE stocks and backfilled with sand.

What the man on th trigger had available was a product of what his collegues elsewhere in the user chain decided.
Gooner1 wrote:
03 Dec 2018 13:13
The inadequacy of the 2-pdr is in no small part due to ammunition provided.

Perhaps. Bit, the lack of APHE and simple HE for the 2-pdr was a user problem, not a problem of the equipment.
Gooner1 wrote:
03 Dec 2018 13:13
Soviet tests of the 2-pdr against a Pz38:
"The 40 mm AP shell does not penetrate front armour 50 (25+25) mm thick. The reason for this is poor quality of the shells. They are destroyed completely on impact.
The 30 mm side armour can be penetrated from 800-1000 meters."
Stug III
"At 50 meters, the 2-pounder only forms a 20 mm deep dent in the StuG's front armour. However, at 100 meters, it manages to penetrate the upper part of the front plate. That result does not repeat, as another shot from 100 meters only makes a 25 mm deep dent. 4 shots from the side, all at 850 meters, go through.
Conclusion: "The 40 mm tank gun penetrates the side of the hull, 30 mm thick, from 850 meters. The front of the hull, 50 mm thick, is not reliably penetrable at any distance due to the poor shell quality. Upon impact, the shells shatter into small fragments."
Pz III
The results are similar to the StuG. It cannot penetrate the front at 100, or even 50, meters.
In the conclusions, the following is noted: "The British 40 mm shell, when fired at a 50 mm armour plate from 50-100 meters, makes a 20-25 mm dent and shatters. "
http://tankarchives.blogspot.com/2013/0 ... tanks.html
And yet, all four of the Pz.III Specials with the L/60 gun and further upgraded armour protection inspected by Col Quilliam in July 1942, were all taken out by the "bloody useless" 2-pdr!!!

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Re: What prevented the QF 3.7-inch AA gun being used in the Anti Tank role.

Post by MarkN » 03 Dec 2018 18:00

Gooner1 wrote:
03 Dec 2018 13:25
MarkN wrote:
02 Dec 2018 21:40
PanzerArmeeAfrika had 16 of its 24 88mm guns sited in stutzpunkte between Sidi Omar and Halfaya. 15. And 21.Pz-Div had just 4 each. Orders had already been issued for a redeployment of 88s for the planned assault on Tobruk however, they were never implemented as Op CRUSADER kicked off. Only 4 of the 16 on the Sollum front were taken away ... and they were used to deal with the breakout from Tobruk.

Maybe it was planned or maybe it just fell that way, but the Germans ended up with 12 88mm to deal with 1ArmyTankBde's 150ish infantry tanks whilst just 8 were available to deal with the 450ish cruiser tanks of 7ArmdDiv.
1st Army Tank Brigade only began Crusader with 132 tanks and had heavy losses - 46 tanks - taking the fortified Omars. Amongst the defenders were a single battery of 88s.
Handwaving again.

How many infantry tanks were taken out by 88s?

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Re: What prevented the QF 3.7-inch AA gun being used in the Anti Tank role.

Post by MarkN » 03 Dec 2018 18:21

Gooner1 wrote:
03 Dec 2018 14:29
MarkN wrote:
30 Nov 2018 18:34
Anyway, in numerous instances, its clear the Germans were patient in their attack, and did so when threats - such as the 2-pdr - had been neutralized. The British, on the otherhand, started their charge at a set time irrespective of the state of the enemy. The difference between the two has NOTHING to do with the equipment each held.
Oh, FFS, the difference between the two is that the German guns had superior effective range.
Oh, FFS, no it wasn't.

The difference was in tactical approach. The British advanced at a specific time regardless of the state of the enemy; the Germans approached when they felt comfortable that the enemy A/Tk guns had been neutralized.

27 May 1940
10th Hussars cavalry charged the 2.Inf-Div(Mot) at Huppy. They do so an hour early beacuse they had not received the message that the French preliminary arty bombardment had been delayed. It was more important for the commander to start his charge on time as per his orders than it was to wait until the German defences had been softened up. The 10th Hussars were ripped apart by PaK36 37mm guns. They didn't use any of their own CS pantsers in any way.

27 May 1940
Queen's Bays cavalry charged the 2.Inf-Div(Mot) at Huppy. Having received the message that the French prelimary bombardment had been delayed, they charged at the revised and correct time. However, the French bombardment was of a general softening up nature rather than specifically targetting German A/Tk defences. It was more important for the commander to start his charge on time as per his orders than it was to wait to see the effect of the softening up. The Queen's Bays were ripped apart by PaK36 37mm guns. They didn't use any of their own CS pantsers in any way.

19 November 1941
Scott-Cockburn's 22nd Armoured Brigade has CS tanks capable of lobbing HE into the Italian A/Tk screen. At least one for each of his pantser squadrons, often a pair. He also had a battery of eight 25-pdrs. He used neither to neutralize the Italian A/Tk screen. He just charged straight into it. The Queen's Bays were ripped apart by Italian 47mm guns as well as field arty firing over sights. His CS pantsers fired a lot of smoke that day. The arty battery was used rather belatedly to offer some pay-back.

21 November 1941
Davy's 4th Armoured Brigade is tasked to grab part of the escarpment overlooking the Trigh Capuzzo and to send a single panser squadron to link up with the Tobruk breakout. He allocates 48 x 25-pdrs to soften up the enemy position for a few minutes before the cavalry and infantry charge goes in. The arty regiments also have FOOs up in the front line with the pantsers to offer further support if necessary. The 6th RTR starts its charge at the alloted time as per the plan - a time which has NOTHING to do with the state of German defences. One squadron and RHQ is wiped out charging across the valley by 47mm Pz.Jag.I guns - perhaps some of SR.155's A/Tk guns too, whilst another is badly mauled trying to offer some flank protection. Also mauled by 47mm Pz.Jag.I and whatever SR.155's had to hand.

British practical doctrine did not allow for A/Tk defences to be neutralized before the cavalry charges commenced. Practical doctrine put the priority on starting at the time stated in the operational order. The range of the various weapons was completely irrelevant to when the charge started.

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