WesWorld

As some of you read here, there is a large tank undergoing testing. I'm torn between a few ideas of what this could be. There are a few constants between the various ideas, these are noted below. Each design will have its own post. Please note the specs are very rough and Im more then willing to adjust them.

All designs will have:
Gun 90mm/53
MG: 2-3 8mm
Spaced Armor plating on front (will get a picture with what I mean soon)

A heavy tank designed to spearhead assaults.

Dimensions
Length: 9m without gun.
Width: 3m
Height: 2.8m

Handling
Weight 57 metric tons
Road Speed: 35kph
Off-road speed: 12kph
Range: 175 km
Engine: 700hp Isotta-Fraschini diesel
Power/Weight ratio: 12.28hp/ton
Suspension: Torsion Beam, seven road wheels

Armament
Main Gun: 90mm/53
Secondary Guns: Two 8mm MG, one hull mounted, one on top of the turret.

Armor(maximum thickness)
Hull Front: 110mm & 2x20mm Spaced plates
Hull Sides: 85mm
Hull Rear: 50mm
Hull Top: 30mm
Hull Bottom: 20mm
Turret Front: 110mm
Mantlet: 110mm
Turret Sides: 80mm & 1x20mm spaced plate
Turret Rear: 80mm & 1x20mm spaced plate
Turret Top: 30mm

Why the spaced armor? Against Anti-tank-rifles 80mm are more than enough...and against shaped charges...are they already common?

These tanks are designed to spearhead a push, and as such may be subjected to weapons fire above the calibers of more portable Ant-Tank weapons. The additional protection is desired to ensure the tanks say in action as long as possible.

Some more fleshed out stats for the P57/45 Princeps Heavy tank A proposal.

Dimensions
Length: 9m without gun.
Width: 3m
Height: 2.8m

Handling
Weight 57 metric tons
Road Speed: 35kph
Off-road speed: 12kph
Range: 175 km
Engine: 700hp Isotta-Fraschini diesel
Power/Weight ratio: 12.28hp/ton
Suspension: Torsion Beam, seven road wheels

Armament
Main Gun: 90mm/53
Secondary Guns: Two 8mm MG, one hull mounted, one on top of the turret.

Armor (degree inclinations are from vertical tilted into the body of the tank)

Front Upper Plate: 110mm @ 30 & 2x20mm Spaced plates
Front Lower Plate: 90mm @ 20 & 1x20mm Spaced plate
Front Upper Angled Plate*: 110mm @ 30 & 2x20mm Spaced plates
Front Lower Angled Plate*: 90mm @15 & 1x20mm Spaced plate
Side Upper Plate: 85mm @ 30
Side Lower Plate: 65mm @ 15
Rear Upper Angled Plate*: 85mm @ 30
Rear Lower Angled Plate*: 65mm @ 15
Rear Upper Plate: 65mm @ 30
Rear Lower Plate: 65mm @ 15
Top: 30mm @ 90
Bottom: 20mm @ 90
Turret Front: 110mm @ 30
Mantlet: 110mm @ Rounded
Turret Sides: 80mm @ 25 & 1x20mm spaced plate
Turret Rear: 80mm @ 15 & 1x20mm spaced plate
Turret Top: 30mm @ 90

*Angled plates run along the hypotenuse of a 45 degree triangle with the legs as a portion of the width and length of the tank.

Hmm.

To the best of my knowledge, no hollow-charge antitank weapons have been employed in combat, and certainly none by Italy. I wonder what experimental work Italy has done to determine that spaced armor adds to the protection of a vehicle from hollow-charge weaponry. And it the additional armor is intended to defeat more common weapons, would not the spacing defeat that? It strikes me as a concept well in advance of its time.

Secondly, I cannot quite follow:

Quoted

*Angled plates run along the hypotenuse of a 45 degree triangle with the legs as a portion of the width and length of the tank.

Could provide a sketch of what this is supposed to represent? I am unable to imagine what you are describing, and therefore cannot properly comment on this aspect of the design.

This design does seem to be in sharp contrast with other Italian tank designs which emphasize mobility. This vehicle has a power/weight ratio towards the lower end of the spectrum which will decrease its value in anything short of a set piece frontal assault. A vehicle of this size cannot be manufactured in infinite numbers, and supporting advancing infantry could be achieved by far less expensive vehicles. If they are expected to breakthrough an enemy's defenses unsupported... well, Iron Coffins would be a good descriptor - a tank is not going to achieve any sort of breakthrough on its on against any sort of prepared defense. JMHO.

Uhm... They're angled? I think I have a vague idea what he might mean...
The upper part of the hull from above would look like this...

\__/

... but then 45 degrees. That's what I think.

Correction, the lower part of the hull has that kind of angling as well. Also, those sections are sloped as well (30 degrees for the upper hull and 15 degrees for the lower hull)

Probably not like this, but it wil lgive you and idea as to what I think he means with the "Angled plates run along the hypotenuse of a 45 degree triangle with the legs as a portion of the width and length of the tank" bit...

I think that snip's design also has a flat front top and bottom like this...

Will respond to this in full tomorrow. For now, this picture. This tank has a similar armor layout to what I am proposing.



And a render better showing the angling of the plates

More in-depth reply to Bruce.

Quoted

To the best of my knowledge, no hollow-charge antitank weapons have been employed in combat, and certainly none by Italy. I wonder what experimental work Italy has done to determine that spaced armor adds to the protection of a vehicle from hollow-charge weaponry. And it the additional armor is intended to defeat more common weapons, would not the spacing defeat that? It strikes me as a concept well in advance of its time.

When I refere to "weapons fire above the calibers of more portable Ant-Tank weapons" I am not referring to HEAT or HESH rounds, but to larger anti-tank guns then could be reasonably considered man-portable that would be found in more static emplacements. Think something like the 88mm Flak guns. Italy has been testing a 57mm fin-stabilized HEAT round for man-portable AT duties (said weapon has been detailed elsewhere and is beginning a phased service entry in the latter half of 1944). But that is not the purpace of the spaced plates (but it may come in handy against HEAT depending on how precise the warheads are). The spaced plates as included are for two reasons. Altering the trajectory of an incoming shell so it strikes the main armor plate in such a way that its practical ability to penetrate armor is reduced and also to serve as an external spall liner that is easily repaired. Think of it like a de-capping plate on a warship. While it is not meant to defeat the rounds on its own, it plays an important roll in the overall protective scheme.

Quoted

Could provide a sketch of what this is supposed to represent? I am unable to imagine what you are describing, and therefore cannot properly comment on this aspect of the design.

I hope the above post helped with visualizing that.

Quoted

This design does seem to be in sharp contrast with other Italian tank designs which emphasize mobility. This vehicle has a power/weight ratio towards the lower end of the spectrum which will decrease its value in anything short of a set piece frontal assault. A vehicle of this size cannot be manufactured in infinite numbers, and supporting advancing infantry could be achieved by far less expensive vehicles. If they are expected to breakthrough an enemy's defenses unsupported... well, Iron Coffins would be a good descriptor - a tank is not going to achieve any sort of breakthrough on its on against any sort of prepared defense. JMHO.

I still have a few ideas for what the tank referenced could be, this is just the first. I do intend for this possible version of the tank to be focused mostly on breakthroughs. I based most of the design off of the Porsche Tiger, which was a very unreliable tank, so I still need to tweek the design to make it more powerful. It might loose a bit of armor to mount a more powerful engine, which should help. In the end tho, variant A is a breakthrough heavy tank. Where it would be primarily used is in the concentrated push on a small part of a defensive line in conjunction with other assault assets to blast a hole for the faster mechanized forces to get though. While the Triarii is a capable tank, it lacks the all round armor to do frontal assaults against large-caliber AT guns when those guns may have shots on its flank.

The confusion, I think, comes from the following

Quoted

Front Upper Plate: 110mm @ 30 & 2x20mm Spaced plates
Front Lower Plate: 90mm @ 20 & 1x20mm Spaced plate
Front Upper Angled Plate*: 110mm @ 30 & 2x20mm Spaced plates
Front Lower Angled Plate*: 90mm @15 & 1x20mm Spaced plate

Based on the photographs you've chosen, I think you have duplicated the armor - you seem to be referring to the upper and lower glacis - the angled armor. Unless your design has hull armor that is upright - i.e. not sloped - I do not think that there is need for what seems a duplicate entry.

"Decapping plate" is a design feature I am completely unaware of for any World War Two tank design. Could you point me to something historical? I am still not convinced that the design is conceivable within the context of 1940s technology.

Quoted

Originally posted by snip
More in-depth reply to Bruce.

When I refere to "weapons fire above the calibers of more portable Ant-Tank weapons" I am not referring to HEAT or HESH rounds, but to larger anti-tank guns then could be reasonably considered man-portable that would be found in more static emplacements. Think something like the 88mm Flak guns. Italy has been testing a 57mm fin-stabilized HEAT round for man-portable AT duties (said weapon has been detailed elsewhere and is beginning a phased service entry in the latter half of 1944). But that is not the purpace of the spaced plates (but it may come in handy against HEAT depending on how precise the warheads are). The spaced plates as included are for two reasons. Altering the trajectory of an incoming shell so it strikes the main armor plate in such a way that its practical ability to penetrate armor is reduced and also to serve as an external spall liner that is easily repaired. Think of it like a de-capping plate on a warship. While it is not meant to defeat the rounds on its own, it plays an important roll in the overall protective scheme.

I understand the thought behind the concept but I am not sure if it makes sense. I am no physics expert but I don't think that a 88mm+ kinetic round would care for a 20mm spaced armor plate.
The OTL Pz. III and IV which had those add-on sideskirts and add-on turret armor were against the soviet AT-rifles as far as I know.
The armor of your tank is thick enough so that AT-Rifles shouldn't be a problem.
To defeat Panzerfaust-like heat rounds you probably wouldn't need 20mm of spaced armor. And as Bruce said the concept is rather advanced especially without combat experience.
Considering the heavy weight and poor power/weight ratio I would get rid of those addon armor plates.

What Daidalos said, when metioning that, I immediately think of the H version of the Pz. IV...


From wiki:

Quoted

An early method of disabling shaped charges developed during World War II was to apply thin skirt armor or meshwire at a distance around the hull and turret of the tank. The skirt or mesh armor (cage armor) triggers the RPG on contact and much of the molten jet that a shaped charge produces dissipates before coming into contact with the main armor of the vehicle.

Side-skirts, of that sort, is not what Snip is describing, as far as I can tell. Called "bazooka plates" by some, they were intended to protect the thinner side armor from hollow-charge projectiles - they are far too thin and flimsy to protect against kinetic projectiles. The Princeps design has these "decapping" plates on its frontal arc and on its turret - and I know of no historical use of such in the period.

I dont think what I ment by de-capping plates carried over correctly. I only ment them as an example in regards to how these plates fit into the overall protection scheme, as something designed to increase the effectiveness of the main amored sections. They are not de-capping plates in the naval architecture sense.

Here is where i got the idea from. T26E4 Super Pershing

Note the front end of the tank.

Yes. And where did this design go? The dustbin.

Edit:

I should add that the vehicle in question was a single test vehicle shipped to Europe in 1945 where the spaced armor was added as a field modification by an ordnance maintenance unit. It appears to have never been tested in combat, and was not subsequently pursued.

Quoted

Originally posted by BruceDuncan
The confusion, I think, comes from the following

Quoted

Front Upper Plate: 110mm @ 30 & 2x20mm Spaced plates
Front Lower Plate: 90mm @ 20 & 1x20mm Spaced plate
Front Upper Angled Plate*: 110mm @ 30 & 2x20mm Spaced plates
Front Lower Angled Plate*: 90mm @15 & 1x20mm Spaced plate

Based on the photographs you've chosen, I think you have duplicated the armor - you seem to be referring to the upper and lower glacis - the angled armor. Unless your design has hull armor that is upright - i.e. not sloped - I do not think that there is need for what seems a duplicate entry.

Let us take a look at the render again. Its the backside of the tank, but the arrangement is correct.

Do you see how there is a third plate that makes up the transition from the side to rear plates? That is what I am trying to get at with the Angled Plate.

A lighter, less protected but more mobile tank for the same roll. Uses a more powerful engine. Basicly a slightly enlarged and uparmored Triarii.

Dimensions
Length: 7m without gun.
Width: 3.25m
Height: 2.8m

Handling
Weight 45 metric tons
Road Speed: 40kph
Off-road speed: 18kph
Range: 200 km
Engine: 700hp Isotta-Fraschini diesel
Power/Weight ratio: 15.55hp/ton
Suspension: Torsion Beam, six road wheels

Armament
Main Gun: 90mm/53
Secondary Guns: Two 8mm MG, one hull mounted, one on top of the turret.

Armor(maximum thickness)
Hull Front: 100mm & 2x20mm Spaced plates
Hull Sides: 85mm
Hull Rear: 50mm
Hull Top: 30mm
Hull Bottom: 20mm
Turret Front: 100mm
Mantlet: 100mm
Turret Sides: 80mm & 1x20mm spaced plate
Turret Rear: 80mm & 1x20mm spaced plate
Turret Top: 30mm

Quoted

Originally posted by Daidalos
I understand the thought behind the concept but I am not sure if it makes sense. I am no physics expert but I don't think that a 88mm+ kinetic round would care for a 20mm spaced armor plate.

Correct. In most applications, spaced armour is actually less effective than a single plate. For instance, five 20mm spaced plates will be less effective than a single 100mm plate, even though the overall thickness is still the same. Similarly, a 20mm sheet isn't going to do jack diddly to deflect a shell larger than, say, 57mm, unless it's fired at very low velocity.

The only time spaced armour actually increases your protection is when you're dealing with shaped charges. In that case, the outer plate causes the charge to fire, and the space between inner and outer plates helps distribute the blast force across a larger area.

A much longer developed design, this would succeed the Triarii in at most 4-5 years.

Dimensions
Length: 7.5m without gun.
Width: 3.5m
Height: 3m

Handling
Weight 50 metric tons
Road Speed: 51kph
Off-road speed: 22kph
Range: 400 km
Engine: 1000hp Isotta-Fraschini diesel
Power/Weight ratio: 20hp/ton
Suspension: Torsion Beam, six road wheels

Armament
Main Gun: 90mm/53 (would eventually get a 105mm gun)
Secondary Guns: Two 8mm MG, one hull mounted, one on top of the turret.

Armor(maximum thickness)
Hull Front: 120mm
Hull Sides: 80mm
Hull Rear: 60mm
Hull Top: 30mm
Hull Bottom: 20mm
Turret Front: 120mm
Mantlet: 120mm
Turret Sides: 80mm
Turret Rear: 80mm
Turret Top: 30mm