Sloped Panzer IV armor?
- Thread starter Shtudmuffin
- Start date
- Status
The M solved it by using a new gearbox and suspension. T34s were still running and fighting in places like Angola in the 70s. Most of the quality issues relate to the ones built in the desperate days of the winter of 41/42, in relocated factories by exausthed workers. The late production ones, and specially the Czechoslovakian built ones that got widely exported were much better built.
If you compare the built quality in early wartime Yak1 and postwar Yak9P you'll see the same quality issues.
Sure, and yet when you read the reports from the tests run in the US in WW2 and after the korean war you can just picture the people who wrote them looking at the picures of T34 in Berlin and saying "that ASB, that piece of junk will never beat the Germans"
To paraphrase Dennis Hulme "If it wins the war, it will be the most beautifull tank in the world"
I know that some of you chaps will have seen this before but for those who have not, I thought you might like to have a look at a sloped armour Panzer IV that I put together from an idea by LeoXiao. The PzKpfw IV SII Ausf B sports sloped armour, revamped suspension and running gear modelled on the VK3001P, up-rated engine a slightly enlarged turret and a 75mm L/56 gun.
Very cool! You are the modeler extraordinaire. Glad the Nazis never built this...
Last edited:
Thank you very much. Please visit https://www.alternatehistory.com/discussion/showthread.php?t=218561 for more on a similarish theme (posts 1213 and 1218 in particular).
Last edited:
Thank you very much. Please visit https://www.alternatehistory.com/discussion/showthread.php?t=218561 for more on a similarish theme (posts 1213 and 1218 in particular).
Looking forward to the Mac!
Sorry for nitpicking, but thats a Panzer III Chassis the Pz IV had 8 and not 6 roadwheels...
The 6 road wheels do make it look a little Panzer III-ish but I assure you, having built the said model, it is built upon a Panzer IV hull. As I pointed out earlier, the model was built for an idea by LeoXiao which not only saw the addition of sloped armour but also a revamped suspension and running gear modelled on the VK3001P prototype tank - 6 slightly larger wheels not 8.
The original model and the start of the process...
I'm not sure I understand sloped armour.
Okay, sloping the armour increases its effective thickness against a horizontal shot, which is Good. But sloping a plate also reduces its vertical height - if you want the sloped plate to extend to same height as a non-sloped plate then it needs to be longer, and the weight gain from the longer plate exactly cancels out effective-thickness increase gained from sloping.
But sloping the armour allows variations in the tank shape and its internal volume, taking it from a cube towards a pyramid with a less obvious profile... however, you also reduce the internal volume which makes it harder to fit inside important things like the crew and the engine, unless you make the tank broader or longer... maybe this is why it wasn't simple to design tanks with sloped armour, particularly not as a derivative of a current design?
But there's a further issue here that confuses me - battleships. The KGVs used thick external vertical belts, while the South Dakotas used inclined belts. Assuming that you want the same vertical height of armour whether you use an inclined or vertical belt, then there is no weight saving - the inclined belt has a greater effective thickness and hence can be thinner, but the weight saved is immediately lost because the plate needs to be higher. In this case how can there be an internal volume argument because the inclined belt was already internal...
Hmm another thing. Looking at the South Dakota wiki page says that it has a belt thickness of 12.2", inclined at 19 degrees, giving an effective thickness of 17.3". But a 12.2" plate inclined at 19 degrees has a horizontal thickness of only 12.2/cos 19 = 12.9".
This makes me think that the "effective-thickness" calculation that I've been using is fundamentally incorrect and that the benefits of sloping are described by a different formula. Can anyone explain please?
Okay, sloping the armour increases its effective thickness against a horizontal shot, which is Good. But sloping a plate also reduces its vertical height - if you want the sloped plate to extend to same height as a non-sloped plate then it needs to be longer, and the weight gain from the longer plate exactly cancels out effective-thickness increase gained from sloping.
But sloping the armour allows variations in the tank shape and its internal volume, taking it from a cube towards a pyramid with a less obvious profile... however, you also reduce the internal volume which makes it harder to fit inside important things like the crew and the engine, unless you make the tank broader or longer... maybe this is why it wasn't simple to design tanks with sloped armour, particularly not as a derivative of a current design?
But there's a further issue here that confuses me - battleships. The KGVs used thick external vertical belts, while the South Dakotas used inclined belts. Assuming that you want the same vertical height of armour whether you use an inclined or vertical belt, then there is no weight saving - the inclined belt has a greater effective thickness and hence can be thinner, but the weight saved is immediately lost because the plate needs to be higher. In this case how can there be an internal volume argument because the inclined belt was already internal...
Hmm another thing. Looking at the South Dakota wiki page says that it has a belt thickness of 12.2", inclined at 19 degrees, giving an effective thickness of 17.3". But a 12.2" plate inclined at 19 degrees has a horizontal thickness of only 12.2/cos 19 = 12.9".
This makes me think that the "effective-thickness" calculation that I've been using is fundamentally incorrect and that the benefits of sloping are described by a different formula. Can anyone explain please?
In the case of a battleship, the incoming shell is not flying horizontally. For example, at 20,000 yards South Dakota's own shells would be descending at 18.9 degrees. Thus at that range you should compare KGV's amidships 14 inch / cos (18.9[FONT=Times New Roman, serif]º[/FONT]) = 14/ 0.946085358828 = 14.8 with 12.2 inch /cos (18.9[FONT=Times New Roman, serif]º[/FONT]+19[FONT=Times New Roman, serif]º[/FONT]) = 12.2/0.810041640446 = 15.06. In addition, the outer 1.25 inch skin might (or might not) decap a shell and might also cause yaw. However, this is only true amidships. The KGV's armour was 15 inches thick at the magazine and at that point was significantly inclined because of the hull's flare.
I am not sure if the 14 and 15 inches were true inches or were defined by the 40 lb equals an inch sometimes used by the RN. There is also the point that British facehardened armour in WW2 was better than US class A armour against battleship shells.
I am not sure if the 14 and 15 inches were true inches or were defined by the 40 lb equals an inch sometimes used by the RN. There is also the point that British facehardened armour in WW2 was better than US class A armour against battleship shells.
As far as AFV go, the issue with sloped armour is relatively easy. There is no loss of internal volume. Take for example, my model of the sloped armour Panzer III, all of the additions went over the existing shape of the vehicle - nothing was cut away, consequently, if anything, the internal volume would be greater. Anywho, very few if any tanks have sloped armour retrofitted in reality and so you make the initial design to have the necessary internal volume you desire in the first place. More importantly, however, the point of sloping the armour is to effectively increase its relative thickness for any given weight. Whilst it is true that a sloped plate will need to be slightly longer in height than a vertical plate, the reduction in weight to produce the same degree of armoured protection far surpasses the additional size and weight of the of the slightly larger sloped plate. Consequently, you end up with a vehicle which might carry the same effective armoured protection as a vertically sided vehicle but is considerably lighter and therefore, faster and more mobile for the same engine power output.
- Status