British Afvs, What Good And Bad Things You Know About Them?

[istvan47]

As we have almost the 100y of the 'tank'..

 

Well, i'd be curious about the british armour in WWII..

 

Quite thick (ok)

 

Almost no sloped (bad!)

 

BUT... the concept of composite armour is very interesting.

 

We know (see german tests) about the danger of the spalling.

 

But british tanks did have two layers of steel, one mid-hardness, and the outer high hardness type.

 

How well and wise they performed with such system?

 

Did those two layers were joined, or they were effectively spaced?

 

I think this arrangment was much better than the simple steel plate, when you want to avoid spalling after hits, such HE, HESH and large non penetrating APs?

 

Remember, that the italian 'semoventi' had a crappy HEAT (EP) that actually performed better than it was meant, because the fuse was 'slow' to explode (=HESH effect, pratically).

 

This was happened also with other artillery shells.

 

So, what was the resilience of british armour vs non penetrating hits?

 

Would have been better to have a sloped armour (like the T-34) or the two layers of steel?

 

I know that this arrangement was later replaced by a complete steel armour (single plate) but this was more due to the AP shells rather than the HE/HESH/HEAT ones. Atleast this is what i figured out of this change.

[Przezdzieblo]

Churchills were found vulnerable to artillery shells hits into front hull. 25-pounder HE would deform internal steel plates under glacis enough to destroy controls - this count as mobility kill. Spaced layout did not helped.

And there was one accident with Churchill VII hit by German 105-150 mm shell. Result was glacis plate separated and fell down, crushing legs of two tankers.

[istvan47]

Really?

 

The Churchill had flawed armour, then?

 

KV-1 was almost impervious to the field gun fire, reading the clashes vs German army (one german 15 cm fired without success until the KV squashed the gun itself).

[nitflegal]

To be fair, the KV-1 was several tons heavier than both the Churchill Mk.1-Mk.VI as well as the heavier Mk.VII.

[scotsman]

Nearly any medium WWII tank is going to be vulnerable to plugged HE fire by 105mm or greater...independent of nationality. Lots of examples or German suffering catastrophic failure in the same circumstance. Take a look at 152mm did on the eastern front to any German AFV it hit...

[rmgill]

Why is thicker armor on a vertical face necessarily bad? If it's built large enough to enclose what it needs to enclose you can save some weight and go for thicker armor rather than sloping it and having more armor weight covering areas that don't actually need covering. Sloped armor requires that you have more space that are impossible to use. Men, ammo, radios and most boxes don't fit very well for servicing in tiny narrow, angled spaces. Fletcher makes this point in the Universal Tank. It has some logic to it I think.

[bojan]

Sure, that must be a reason everyone ditched sloped armor after war. Right.

[Markus Becker]

Remember, that the italian 'semoventi' had a crappy HEAT (EP) that actually performed better than it was meant, because the fuse was 'slow' to explode (=HESH effect, pratically).

 

This was happened also with other artillery shells.

 

Most interesting news to me. Thanks!

[BLAH]

Some website had up a whole heap of BDAs on Comets (pictures and accounts).

 

They seemed to stay in one piece and not blow up when hit with fausts and 75/88mm guns, which is pretty good if you're not the unlucky person in the line of penetration. 75 and 88mm didn't have much trouble penetrating them.

 

So, the ammunition stowage seemed to be pretty good. Though an AT mine breaching the floor probably would set it off.

[rmgill]

Sure, that must be a reason everyone ditched sloped armor after war. Right.

 

 

 

 

 

Edited September 8, 2014 by rmgill

[T-44]

 

Sure, that must be a reason everyone ditched sloped armor after war. Right.

[Leopard II image]

 

I would hardly situate the Leo II "after war" in the way Bojan was probably implying [namely: after the war and before ceramic armor developments: e.g. Paton series, T54/5, AMX, LEO I, Chieftain etc.]

Edited September 8, 2014 by T-44

[bojan]

But you can not have discussion with Ryan regarding British armor - heavens forbid Brits were wrong...

[Getz]

I think there is a valid point there. Whilst sloped armour is better, that doesn't make stepped armour of sufficient thickness bad.

 

The fact that the British did not adopt sloped armour until the Centurion does not mean the preceding designs were badly protected in the frontal arc per-se, merely that the protection scheme chosen was inefficient by weight compared to their contemporaries. I certainly wouldn't dismiss a tank as poorly armoured solely on the layout of it's hull front - but then again I'd think that this was too obvious to require stating. Which glacis plate would you rather be behind when your tank takes a hit? The stepped armour of a Churchill or the sloped armour of an M24 (to pick opposing extremes)?

[Colin]

Sloped armour for the A10 and A13 would have been way more useful than MG turrets!

 

 

 

Here is another candidate for some sloped armour

 

Edited September 9, 2014 by Colin

[rmgill]

But you can not have discussion with Ryan regarding British armor - heavens forbid Brits were wrong...

Yeah, that's it.

 

I argue that there was in fact some vein to allow for the design difference and your rebuttal is that it was TOTALLY wrong.

 

You're the one arguing on Right vs Wrong whereas I'm arguing that there are design tradeoffs with both styles.

 

What does sloped armor buy you now? What's the armor angle on the front of the Abrams? Does that buy ANY protection against projectiles by virtue of it's slope?

[Colin]

I suspect interwar and early WWII British tanks vertical plates and construction was due to financial cost and manufacturing limitations rather than weight or ballistic effect. After all they did build the Matilda 1 where costs ruled supreme. Where I suspect weight played a factor is that an increase in weight would require stronger components, making the tank cost more.

[bojan]

Ryan, M1 Glacis and front turret, Challenger front turret and upper front hull, Leo's glacis, T-xx glacis, etc etc. They still get you extra protection by virtue of slope and simple trigonometry.

But you can ignore and cherry pick issues as long as you like it, it won't make non-sloped armor good thing in WW2.

BTW, did not notice stepped hull front on Cent pic you posted... Or will you conveniently ignore it as turret armor is not sloped?

Edited September 9, 2014 by bojan

[sunday]

What I have always found remarkable in the Cruiser tanks is that they used sloped armor only on the turret sides. But turret front was vertical.

 

And do not forget rivets.

 

Nor TOG.

[rmgill]

The Universal Tank
David Fletcher
Ch 6 Consolidation, pp 91-92

It may be asked, why, instead of slapping more armor on to existing vertical surfaces, some attempt was not made to design sloped armor for British Tanks? The Sherman had this feature, on the front at least, while the T-34 and German Panther were renowned for it. Certainly most crews believed in it, and anyone who had wriggled out of his Sherman to see where an 88-mm round had gouged out a lump of armor as it glanced off, where it ought to have penetrated and killed him, was obviously going to be difficult to convince otherwise. A sober appraisal of the respective advantages was laid out in a brief discussion paper by Colonel F. W. Gordon-Hall and, as we have already seen, what that officer said on tank design generally deserved to be taken seriously. Gordon Hall stated that the first duty of any tank designer was to enclose the vital parts of a tank with a suit of armor in which no internal space was wasted. The ideal shape he suggested was a sphere, but in practical terms it had to be a box because major components such as the engine, transmission and fighting compartments formed natural rectangular blocks. Taking the basic plate to be 100mm thick, he showed that similar protection could be obtained from a plate sloped at 30 degrees which was 80-mm thick. However this would have a greeter surface area, also enclosing some inessential space, so the weight saving would be minimal.

As for the assumption that angled plates deflect shot, Gordon-Hall pointed out that this depended on the shape of the armour-piercing projectile, but that in any case this was only likely to happen at angles of slope between 40 and 55 degrees. Against 30-degree plate, the accepted norm, the shot would tend to turn inwards on striking, rather than glance off. In pursuing this, one is liable to become trapped in the heady realms of higher mathematics, and the Colonel's intention was to keep it simple enough or ordinary mortals to comprehend while also, no doubt, stirring up some discussion. He pointed out, for instance, that unless the ground was entirely level, two tanks engaged in a firefight could be at different elevations, in which the advantage of angled plate might be entirely negated. What he did not mention was that even a tank built of all vertical plates on a flat surface could meet its enemy obliquely and thus achieve the effect of angled plate in relation to a strike. His conclusion was that vertical plate would always give at least it's designed performance, whereas angled plate could not be relied upon because it depended very much on the angle of attack.

It would be wrong to assume from this that British tank designers were actually a lot more sensible than their foreign counterparts. Enough has already been written to suggest that expediency had as much to do with it as expertise, but Colonel Gordon-Hall's paper is an interesting challenge to accepted views both then and since.

 

Bojan, I suggest you read that and, if you are still butt-hurt about it, why you draft a pair of letters to both David Fletcher and Colonel F.W. Gordon-Hall. What you do with those letters is entirely up to you. You can sit on them for all I care.

Edited September 9, 2014 by rmgill

[rmgill]

What I have always found remarkable in the Cruiser tanks is that they used sloped armor only on the turret sides. But turret front was vertical.

 

And do not forget rivets.

 

Nor TOG.

Depending on the model, some of that was armor additions in the case of the A13 A2.

 

The riveting was a limitation of manufacturing methods available at the time. As soon as electric welding became more feasible and available, it was used in great form to compose the composite components as in the Turret of the Cromwell and Churchill as well as the welded hulls. Among other things it also enabled more tightly sealed hulls aiding in the deep wading functions or fording for that matter. This is a notable difference between early riveted hull Bren Carriers and later welded hull carriers.

[rmgill]

BTW, did not notice stepped hull front on Cent pic you posted... Or will you conveniently ignore it as turret armor is not sloped?

Now, to address that last point which you seemingly fail to understand.

 

The lack of a front mounted hull Machine gun absolves the need for a front vertical face. So does the lack of a direct vision aperture. Both apertures provides a weak point in the frontal armor. And in the case of the hull MG, the gunner's space is needed for ammo stowage.

 

Again from the Universal tank.

Page 121.

Some, the DRAC amongst them, still hankered after a hull machine gun as well, but this was finally rejected following trials in an experimental hull, for a variety of reasons. In the first place, such a mounting compromised the integrity of the sloping form thill plate, and it could only be fitted at the expense of ten rounds of ammunition. Furthermore, since no co-driver was contemplated, it was considered difficult for the driver to reload or clear stoppages while trying to drive.

 

Edited September 9, 2014 by rmgill

[Loopycrank]

The Universal Tank

David Fletcher

Ch 6 Consolidation, pp 91-92

 

It may be asked, why, instead of slapping more armor on to existing vertical surfaces, some attempt was not made to design sloped armor for British Tanks? The Sherman had this feature, on the front at least, while the T-34 and German Panther were renowned for it. Certainly most crews believed in it, and anyone who had wriggled out of his Sherman to see where an 88-mm round had gouged out a lump of armor as it glanced off, where it ought to have penetrated and killed him, was obviously going to be difficult to convince otherwise. A sober appraisal of the respective advantages was laid out in a brief discussion paper by Colonel F. W. Gordon-Hall and, as we have already seen, what that officer said on tank design generally deserved to be taken seriously. Gordon Hall stated that the first duty of any tank designer was to enclose the vital parts of a tank with a suit of armor in which no internal space was wasted. The ideal shape he suggested was a sphere, but in practical terms it had to be a box because major components such as the engine, transmission and fighting compartments formed natural rectangular blocks. Taking the basic plate to be 100mm thick, he showed that similar protection could be obtained from a plate sloped at 30 degrees which was 80-mm thick. However this would have a greeter surface area, also enclosing some inessential space, so the weight saving would be minimal.

 

As for the assumption that angled plates deflect shot, Gordon-Hall pointed out that this depended on the shape of the armour-piercing projectile, but that in any case this was only likely to happen at angles of slope between 40 and 55 degrees. Against 30-degree plate, the accepted norm, the shot would tend to turn inwards on striking, rather than glance off. In pursuing this, one is liable to become trapped in the heady realms of higher mathematics, and the Colonel's intention was to keep it simple enough or ordinary mortals to comprehend while also, no doubt, stirring up some discussion. He pointed out, for instance, that unless the ground was entirely level, two tanks engaged in a firefight could be at different elevations, in which the advantage of angled plate might be entirely negated. What he did not mention was that even a tank built of all vertical plates on a flat surface could meet its enemy obliquely and thus achieve the effect of angled plate in relation to a strike. His conclusion was that vertical plate would always give at least it's designed performance, whereas angled plate could not be relied upon because it depended very much on the angle of attack.

It would be wrong to assume from this that British tank designers were actually a lot more sensible than their foreign counterparts. Enough has already been written to suggest that expediency had as much to do with it as expertise, but Colonel Gordon-Hall's paper is an interesting challenge to accepted views both then and since.

 

Bojan, I suggest you read that and, if you are still butt-hurt about it, why you draft a pair of letters to both David Fletcher and Colonel F.W. Gordon-Hall. What you do with those letters is entirely up to you. You can sit on them for all I care.

 

 

Since when is basic trig "higher mathematics?"

 

It's quite simple; sloped armor is no lighter for a given areal density. This is so trivially easy to prove that I need not bother. The real question is whether slope gives any additional protection relative to its LOS thickness. Against full caliber AP and APDS sloped armor is disproportionately effective. Against HEAT slope is only modestly effective, since the slope per se does nothing against the jet, but the slope may cause asymmetric liner collapse. APFSDS apparently has a tendency to normalize or something, since as per the Odermatt equation sloped armor is less effective, pound for pound, than flat armor.

 

There's a chart in Technology of Tanks showing the relationship between normal thickness, LOS thickness and "effective" thickness of various armor slopes against AP/APDS type threats. A plate sloped at 60 degrees from the vertical, for example, has LOS thickness twice as great as its normal thickness (think 30 60 90 triangle), but an "effective" thickness nearly four times greater. So, against AP/APDS type threats, armor sloped at 60 degrees from the vertical has nearly double the mass efficiency.

 

However, against APFSDS type threats, armor sloped 60 degrees from the vertical would only be about 60% as effective on a weight basis as flat armor.

[BLAH]

Even without sloped armor, the Comet was a better tank than the T-34-85 and Sherman (and effectively close to the Panther as far as gun and protection against powerful AT guns goes).

 

You can say that it wasn't hindered by such during that time, and it was in the same weight class as the above two.

[Max H]

Even without sloped armor, the Comet was a better tank than the T-34-85 and Sherman (and effectively close to the Panther as far as gun and protection against powerful AT guns goes).

 

You can say that it wasn't hindered by such during that time, and it was in the same weight class as the above two.

 

Uh, how? It has noticeably less front armour than either of the other mediums, which would make a substantial difference in vulnerability ranges for the common german 75's (and the panther is entirely superior). While it does have a powerful gun, it's only slightly better than the gun on T-34-85 so would still be unable to penetrate the panther upper glacis while penetrating just about everything else

[Colin]

The Universal Tank

David Fletcher

Ch 6 Consolidation, pp 91-92

 

It may be asked, why, instead of slapping more armor on to existing vertical surfaces, some attempt was not made to design sloped armor for British Tanks? The Sherman had this feature, on the front at least, while the T-34 and German Panther were renowned for it. Certainly most crews believed in it, and anyone who had wriggled out of his Sherman to see where an 88-mm round had gouged out a lump of armor as it glanced off, where it ought to have penetrated and killed him, was obviously going to be difficult to convince otherwise. A sober appraisal of the respective advantages was laid out in a brief discussion paper by Colonel F. W. Gordon-Hall and, as we have already seen, what that officer said on tank design generally deserved to be taken seriously. Gordon Hall stated that the first duty of any tank designer was to enclose the vital parts of a tank with a suit of armor in which no internal space was wasted. The ideal shape he suggested was a sphere, but in practical terms it had to be a box because major components such as the engine, transmission and fighting compartments formed natural rectangular blocks. Taking the basic plate to be 100mm thick, he showed that similar protection could be obtained from a plate sloped at 30 degrees which was 80-mm thick. However this would have a greeter surface area, also enclosing some inessential space, so the weight saving would be minimal.

 

As for the assumption that angled plates deflect shot, Gordon-Hall pointed out that this depended on the shape of the armour-piercing projectile, but that in any case this was only likely to happen at angles of slope between 40 and 55 degrees. Against 30-degree plate, the accepted norm, the shot would tend to turn inwards on striking, rather than glance off. In pursuing this, one is liable to become trapped in the heady realms of higher mathematics, and the Colonel's intention was to keep it simple enough or ordinary mortals to comprehend while also, no doubt, stirring up some discussion. He pointed out, for instance, that unless the ground was entirely level, two tanks engaged in a firefight could be at different elevations, in which the advantage of angled plate might be entirely negated. What he did not mention was that even a tank built of all vertical plates on a flat surface could meet its enemy obliquely and thus achieve the effect of angled plate in relation to a strike. His conclusion was that vertical plate would always give at least it's designed performance, whereas angled plate could not be relied upon because it depended very much on the angle of attack.

It would be wrong to assume from this that British tank designers were actually a lot more sensible than their foreign counterparts. Enough has already been written to suggest that expediency had as much to do with it as expertise, but Colonel Gordon-Hall's paper is an interesting challenge to accepted views both then and since.

 

Bojan, I suggest you read that and, if you are still butt-hurt about it, why you draft a pair of letters to both David Fletcher and Colonel F.W. Gordon-Hall. What you do with those letters is entirely up to you. You can sit on them for all I care.

Well the comments by the Colonel are somewhat useful, going by the overall results of the British tank designers in the interwar and early war period, their tank designs were poor as were the machinery components. So one has to ask as how much of the above is justification of a path already taken and no wish to deviate from it. Politics and interservice bickering has been around since the chariot at least.