N-L-M

The MTU 883 is not at all smaller than the AVDS 1790. The engines are approximately the same length, similar width (though the 883 is square and the AVDS is trapezoidal in section and a tad wider at the top), and with the cooling system on top similar height (though the MTU has a more optimised slope for hiding behind the glacis). You would note, that the engine compartment on the Merk 4 is not notably shorter than the same on the Merk 3.
Likewise, the Renk 325 transmission that goes with the 883 is slightly fatter than the Renk 304 which goes with the 1200 HP AVDS 1790, so there's no real room saved in the engine compartment. Definitely not the approximately 60 cm you'd need to cram in another seat.
I would also question the tactical utility of being able to seat more people in a Namer, as it already carries a full infantry squad.
 
The IDF don't appear to have said anything about it yet, but they tend to keep quiet anyway.

The MTU 883 is not at all smaller than the AVDS 1790. The engines are approximately the same length, similar width (though the 883 is square and the AVDS is trapezoidal in section and a tad wider at the top), and with the cooling system on top similar height (though the MTU has a more optimised slope for hiding behind the glacis). You would note, that the engine compartment on the Merk 4 is not notably shorter than the same on the Merk 3.
Likewise, the Renk 325 transmission that goes with the 883 is slightly fatter than the Renk 304 which goes with the 1200 HP AVDS 1790, so there's no real room saved in the engine compartment. Definitely not the approximately 60 cm you'd need to cram in another seat.
I would also question the tactical utility of being able to seat more people in a Namer, as it already carries a full infantry squad.
 
The IDF don't appear to have said anything about it yet, but they tend to keep quiet anyway.

Per "surviving the ride", the 6x6 with 2 front axles was intended to solve the problem of losing all mobility when the front wheel hit a landmine, by just having an extra sacrificial pair up front. This extra pair of wheels however led to substantial yaw stability issues and was not successful.

Per "surviving the ride", the 6x6 with 2 front axles was intended to solve the problem of losing all mobility when the front wheel hit a landmine, by just having an extra sacrificial pair up front. This extra pair of wheels however led to substantial yaw stability issues and was not successful.

Yooo @Toxn what were y'all smoking back in the days?

Landmines. And bush warfare. And the fumes of late colonialism. And whatever (probably radioactive) drug the cold war was. And, you know, industrial-strength racism.
 
Honestly, given the above, us making 6x6 mad max vehicles in the 70s and 80s seems positively sane.

Gonna have to ask you all to cool your jets and discuss things in a civilized manner. It's easy to get excited about things on the internet, please take it easy, especially in the current year.

Gonna have to ask you all to cool your jets and discuss things in a civilized manner. It's easy to get excited about things on the internet, please take it easy, especially in the current year.

Gonna have to ask you all to cool your jets and discuss things in a civilized manner. It's easy to get excited about things on the internet, please take it easy, especially in the current year.

Gonna have to ask you all to cool your jets and discuss things in a civilized manner. It's easy to get excited about things on the internet, please take it easy, especially in the current year.

And the vision of Naval Group (in charge of the design study).
 
 

 
 
Edit: More pics from different angles in this thread:
 

Having very recently finished a design cycle, I can now offer insight into how I do things.
The first thing I do is look at the requirements, and the available options (whether limited by name or simply similar in performance), and try to figure out a first order approximation of what it is I'm hoping to get done. It's usually at this point that I sketch out the design in pencil and make a list of design features I intend to include in the design - this typically helps solidify the concept in my mind, as well as making sure I don't miss anything major along the way. I set myself certain design goals to guide myself along the way at this point, as they shape to an extent how I want the design to end up.
It's also at this stage that I tend to obsessively google ballistic charts, gun blueprints, and internal pics of relevant vehicles, for cribbing the designs off later.

This approach is very "front heavy", in that it requires you to have a very good image of what you want to get done in your mind before you ever really touch the CAD software, but it does mean that other than minor tweaks, you only CAD once. The Norman, Fox, .224 Rapier, and now BT-5-76/43 were all substantially first shots. Some details were ironed out as the design progressed (typically, precise dimensions are initially guessed and then adjusted as needed), but the concept, down to, say, the location of the extra periscope on the roof, was sketched out on day 0. This approach also means modelling is easier, as you are focused on carrying out the decisions of the design committee (you) and not making the decisions themselves.

As the design progresses, the day 0 first order approximations may turn out to be incorrect. The BT-5-76/43 was initially supposed to only have thick side-skirts along the fighting compartment, with thinner ones to the rear, but then I realized I had a sufficient mass budget to allow me to go wild, so I did.

As you go, it's important to keep whatever goals you set for yourself in mind. With a sufficiently blank slate, it's easy to get lost and start designing spaceships with All The Features TM, when you should be focusing on core capabilities. For the Norman, the core was a tank on par with late Centurions; for the BT-5-76/43, the core was "I do not want to touch the driveline or the turret ring in the process of improving this vehicle". Some features (like vision cupolas) are basically free improvements if you remember to include them; others (like fuckoff big guns) require substantial tradeoffs which must be viewed in the context of their effect on the bottom line of the design goal.

I tend to start from the turret, then the hull, then the armament, then systems, and finally suspensions and the like. The wonders of parametric modelling mean you can make a rough hull shape, design components to fit, and then rejigger the hull as required by the systems.

There's no good replacement for pencil sketches and barely legible scribbles on paper, in terms of focusing one's design intent into practice. CAD is just a way of translating that scribble into something others can understand too.

Final Judgement
 
Third place: Carro Armato P.35/105
 
I hate having to place this vehicle third, as it's the most impressive in terms of paper stats and just looks so... right. It looks like exactly the sort of late-war (for them, anyway) prototype that the Italians would have produced, only for it to become forgotten under a fountain of "hurr durr pasta tank" memes. And talk about performance! What @Lord_James has managed to do here is wring a Tiger-analogue out of a 28-tonne pre-war vehicle.
 
Unfortunately, when I try to game this thing out the numbers end up being stark. As something closer to a ground-level rebuild there would never have been more than a handful of these things around by the time that the Allies hit the beaches on Sicily. In combat, of course, this thing is a beast - a fully-equipped force riding in at the right moment would have easily made it to the outskirts of town and perhaps to hitting the beaches beyond. So I gave it its moment in the sun. From there, however, you're left with only a handful of these things pootling around amidst an ever-worsening spares situation. Which is a recipe for expensive bunkers.
 
Second place: T-28/43
 
As with the previous entry, I hate having to place this vehicle second. @heretic88did a great job in terms of coming up with a vehicle that required the absolute minimum amount of fabrication, but still materially added to the effectiveness of the tank. His additions were all well-chosen with the task in mind, and would have resulted in a very workable vehicle for an Italian army and industrial system that was rapidly backpedaling. Unfortunately he also chose the vehicle that I left in as a poison pill - the one which could only ever have been produced in miniscule numbers. I ran the math on all the vehicles captured by the Germans over the course of their first year on Soviet soil, and there's no way that they ever got ahold of more than a hundred T-28s in total. Add in a year and a half of back and forth warfare, neglect, wastage and (most likely) some tanks being fed into steel mills and you're never going to produce a fleet of these things worth talking about. This version of an up-gunned T-28 would, I feel, be destined to become an unfairly-forgotten curiosity that Allied crews chalked up as some sort of lesser-known German tank that somehow ended up being confined to a single island campaign.
 
Winner: Carro Armato BT-5-76/43
 
Yet again I have qualms about this one, not least because N-L-M is my eternal rival (flattering myself). I'm also decidedly leery of the look of the thing and his (admittedly brilliant) solution to up-gunning it. In the end the thing that swung it for me was this: the Germans probably had more BT-5s than they knew what to do with, and once you take away the 76mm autoloader thingy (and maybe the gun-linked HMG) all the changes N-L-M is proposing are eminently sensible. I feel that the BT series of tanks was and is criminally underrated, and its reputation for poor performance probably had more to do with how many of the damn things were captured in depots rather than in fighting. In my mind, the BT-5-76/43, with its horrific (and probably accurate) name, comes the closest to giving the Italians a foreign-derived vehicle that they can actually use effectively and in numbers.
 
To @N-L-M: congratulations and please contact me about your $25 prize! To the rest of the contestants: well done, and damn you for making me work so hard to pick out a winner
 

Having very recently finished a design cycle, I can now offer insight into how I do things.
The first thing I do is look at the requirements, and the available options (whether limited by name or simply similar in performance), and try to figure out a first order approximation of what it is I'm hoping to get done. It's usually at this point that I sketch out the design in pencil and make a list of design features I intend to include in the design - this typically helps solidify the concept in my mind, as well as making sure I don't miss anything major along the way. I set myself certain design goals to guide myself along the way at this point, as they shape to an extent how I want the design to end up.
It's also at this stage that I tend to obsessively google ballistic charts, gun blueprints, and internal pics of relevant vehicles, for cribbing the designs off later.

This approach is very "front heavy", in that it requires you to have a very good image of what you want to get done in your mind before you ever really touch the CAD software, but it does mean that other than minor tweaks, you only CAD once. The Norman, Fox, .224 Rapier, and now BT-5-76/43 were all substantially first shots. Some details were ironed out as the design progressed (typically, precise dimensions are initially guessed and then adjusted as needed), but the concept, down to, say, the location of the extra periscope on the roof, was sketched out on day 0. This approach also means modelling is easier, as you are focused on carrying out the decisions of the design committee (you) and not making the decisions themselves.

As the design progresses, the day 0 first order approximations may turn out to be incorrect. The BT-5-76/43 was initially supposed to only have thick side-skirts along the fighting compartment, with thinner ones to the rear, but then I realized I had a sufficient mass budget to allow me to go wild, so I did.

As you go, it's important to keep whatever goals you set for yourself in mind. With a sufficiently blank slate, it's easy to get lost and start designing spaceships with All The Features TM, when you should be focusing on core capabilities. For the Norman, the core was a tank on par with late Centurions; for the BT-5-76/43, the core was "I do not want to touch the driveline or the turret ring in the process of improving this vehicle". Some features (like vision cupolas) are basically free improvements if you remember to include them; others (like fuckoff big guns) require substantial tradeoffs which must be viewed in the context of their effect on the bottom line of the design goal.

I tend to start from the turret, then the hull, then the armament, then systems, and finally suspensions and the like. The wonders of parametric modelling mean you can make a rough hull shape, design components to fit, and then rejigger the hull as required by the systems.

There's no good replacement for pencil sketches and barely legible scribbles on paper, in terms of focusing one's design intent into practice. CAD is just a way of translating that scribble into something others can understand too.

So our processes are basically opposites of each other 

Having very recently finished a design cycle, I can now offer insight into how I do things.
The first thing I do is look at the requirements, and the available options (whether limited by name or simply similar in performance), and try to figure out a first order approximation of what it is I'm hoping to get done. It's usually at this point that I sketch out the design in pencil and make a list of design features I intend to include in the design - this typically helps solidify the concept in my mind, as well as making sure I don't miss anything major along the way. I set myself certain design goals to guide myself along the way at this point, as they shape to an extent how I want the design to end up.
It's also at this stage that I tend to obsessively google ballistic charts, gun blueprints, and internal pics of relevant vehicles, for cribbing the designs off later.

This approach is very "front heavy", in that it requires you to have a very good image of what you want to get done in your mind before you ever really touch the CAD software, but it does mean that other than minor tweaks, you only CAD once. The Norman, Fox, .224 Rapier, and now BT-5-76/43 were all substantially first shots. Some details were ironed out as the design progressed (typically, precise dimensions are initially guessed and then adjusted as needed), but the concept, down to, say, the location of the extra periscope on the roof, was sketched out on day 0. This approach also means modelling is easier, as you are focused on carrying out the decisions of the design committee (you) and not making the decisions themselves.

As the design progresses, the day 0 first order approximations may turn out to be incorrect. The BT-5-76/43 was initially supposed to only have thick side-skirts along the fighting compartment, with thinner ones to the rear, but then I realized I had a sufficient mass budget to allow me to go wild, so I did.

As you go, it's important to keep whatever goals you set for yourself in mind. With a sufficiently blank slate, it's easy to get lost and start designing spaceships with All The Features TM, when you should be focusing on core capabilities. For the Norman, the core was a tank on par with late Centurions; for the BT-5-76/43, the core was "I do not want to touch the driveline or the turret ring in the process of improving this vehicle". Some features (like vision cupolas) are basically free improvements if you remember to include them; others (like fuckoff big guns) require substantial tradeoffs which must be viewed in the context of their effect on the bottom line of the design goal.

I tend to start from the turret, then the hull, then the armament, then systems, and finally suspensions and the like. The wonders of parametric modelling mean you can make a rough hull shape, design components to fit, and then rejigger the hull as required by the systems.

There's no good replacement for pencil sketches and barely legible scribbles on paper, in terms of focusing one's design intent into practice. CAD is just a way of translating that scribble into something others can understand too.

At -10 degrees depression, the gun only just hits the turret roof at full recoil but the tube clips through.


Limiting depression to -5 degrees solves that problem.

Perhaps ejecting not with a tube but with a T-62 style roof hatch (only on the front of the turret) would allow the full 10 degrees of depression.


Also apparently elevation is +15 not +10 as previously stated. I dun goofed there.
The tube requires a bit of a mantlet expansion but nothing special.
 

The latter. At -5 degrees they're aligned, as the barrel elevates and the breech drops theres a bit of a drop from the height of the hopper feed to the ramming tray, but it isn't very far to go.

Carro Armato BT-5-76/43



General specs:
Weight:
15t nominal, 16 t loaded.
Length, gun forwards: 7m
Width: 2.3 m
Height: 2.3 m to turret roof

Crew: Commander, Gunner/loader, Driver.

Armament: 45mm, 75mm or 76mm gun, roof mounted HMG, coax MG, and grenade projectors.

Mobility: Slightly reduced from BT-5 to cope with added weight, but still excellent. 25 HP/T at 16 tons.

Survivability: Excellent against 37mm, acceptable vs 75mm, borderline against 57mm, none against 76mm.
Detailed description:
 

Carro Armato BT-5-76/43



General specs:
Weight:
15t nominal, 16 t loaded.
Length, gun forwards: 7m
Width: 2.3 m
Height: 2.3 m to turret roof

Crew: Commander, Gunner/loader, Driver.

Armament: 45mm, 75mm or 76mm gun, roof mounted HMG, coax MG, and grenade projectors.

Mobility: Slightly reduced from BT-5 to cope with added weight, but still excellent. 25 HP/T at 16 tons.

Survivability: Excellent against 37mm, acceptable vs 75mm, borderline against 57mm, none against 76mm.
Detailed description:
 

Carro Armato BT-5-76/43



General specs:
Weight:
15t nominal, 16 t loaded.
Length, gun forwards: 7m
Width: 2.3 m
Height: 2.3 m to turret roof

Crew: Commander, Gunner/loader, Driver.

Armament: 45mm, 75mm or 76mm gun, roof mounted HMG, coax MG, and grenade projectors.

Mobility: Slightly reduced from BT-5 to cope with added weight, but still excellent. 25 HP/T at 16 tons.

Survivability: Excellent against 37mm, acceptable vs 75mm, borderline against 57mm, none against 76mm.
Detailed description:
 

It's happening

Ok, here is my T-28 upgrade.
 
T-28/43
 
Mass: ~30 tons
Crew: 4
 
Protection:
(angles unchanged compared to original tank, except the side of driver's compartment)
 
Lower front hull: 30+50mm
Upper front hull: 30+50mm
Sides: 20mm base, 30mm at driver's compartment, 20+10mm suspension area
Top: 10-15mm
 
Frontal part of turret: 30+50mm
Rear part of turret: 30+30mm
Top: 15mm
Cupola: 100mm 
 
Main armament:
75mm Pak-97/38, 70 rounds (+optional racks on both sides of driver)
Useable ammunition: AP, HEAT, HE
Secondary armament:
1x DT machine gun, modified to use italian 8x59mm ammo. 2000 rounds.
 
Observation/aiming devices:
- telescopic sight TOP
- periscopic sight PT-1
- panoramic sight PTK
- 1x periscope for gunner, aimed to side (replacing the vision slit, now covered by armor)
- commander's cupola with 5 vision ports (Panzer IV type)
 
Engine:
M-17T/43, gasoline, uprated to 550hp.
Power to weight ratio: ~18.3 hp/ton
 
Other improvements:
- the removal of MG turrets resulted in a free space on both sides of the driver. It can be used for storing tools for maintenance, personal gear for crew, or extra ammo.
- added fume extractor fan on turret top
- replaced soviet radios
- modified, smaller hatch for loader, since the commander's cupola is quite big.
- turret became quite heavy (and probbly imbalanced to a degree) with add-on armor, so a reinforced traverse mechanism is added.
- old radio antenna rails retained, useful for attaching camouflage. 
 

 

Carro Armato P 35/105
 

 
Length (hull): 7.44m 
Width: 2.87m (3.52m with skirt)
Height: 2.9m 
 
Mass: 31.5 tonnes (+3.4 tonnes with applique) 
 
Armor (additional armor in parenthesis): 
Front Glacis: 45mm @ 53 degrees (+25mm)
Lower Glacis: 30mm @ 23 degrees
Hull Sides: 20mm (+8mm skirt)(+25mm upper hull sides)
Hull Roof: 15mm 
Drivers Front Hatch: 60mm @ 53 degrees (+8mm) 
Drivers Roof Hatch: 15mm 
 
Turret Front: 60mm (+25mm) 
Forward Turret Sides: 30mm (+25mm) 
Rear Turret Sides: 30mm (+8mm)
Turret Rear: 30mm (+8mm)
Turret roof: 15mm 
Commanders copula: 45mm (+25mm)
Gun Mantle: 45mm 
Roof Hatches: 15mm 
 
Armament: 
Cannone Ansaldo da 105/25 (34 rounds) 
8mm Breda mod. 38 machine gun (1008 rounds) 
An additional Breda 38 for anti air purposes can be mounted on the roof, operated by one of the loaders (the pole in the center of the turret)
Azimuth: 360 degrees
Elevation: -13 to +25 degrees 
 
Built in an effort to provide protected, versatile, and heavy firepower for the Regio Esercito, the P 35/105 is a heavily modified T-28 from the Russian army. Removing all previous armament, and widening the turret ring to accommodate a larger, 4 man turret, with commander's copula and radio (a rare luxury in the Italian army) and 105mm howitzer. During trials, it was found that the vehicles armor was far to light to combat the expected Allied tanks that she would be engaging (namely, the M4 Sherman), and an additional ~3.5 tons of spaced armor and armored skirts were added to provide resistance to the 75mm M1 gun. The main armament was the 105mm/25 Ansaldo cannon, the same fitted to the Semovente 105/25 SPG, and serviced by 2 loaders. Additional armament included a 8mm Breda 38 machine gun coaxially mounted with the main gun, and a 2nd 8mm Breda mounted on the roof, for defense against aircraft. The heavy armor and gun caused some stress on the suspension, namely the forward elements, which cause the tank to dip nose first. Regardless, the tank was still fielded in combat, but too late to be used by the Italian army, instead seeing service with the German army. 
 
P 35's in action!
 
 
She's a little heavier than I expected, but that's not a bad thing, because it's mostly all armor, which she'll need fighting M4s. The applique is reminiscent of the very new Pz.3M, while also reinforcing the vulnerable hull sides, similar to the T-28E; after all, "Imitation is the sincerest form of flattery" . Either way, Italy was on the ropes by 1943, so these tanks would have been captured by the Germans soon, anyway, and the company might be in a better situation afterwards if the overlords are impressed, or at least pleased, to see such a vehicle ripe and ready to use.